This is zsh.info, produced by makeinfo version 6.7 from zsh.texi.

     Zsh 5.9.999.3-test, Aug 08, 2026

     Zsh Development Group

     Copyright © 1990–2026, Zsh Development Group

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* zsh: (zsh.info). the Z shell
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File: zsh.info,  Node: Top,  Next: Introduction,  Up: (dir)

The Z Shell Manual
******************

     Zsh 5.9.999.3-test, Aug 08, 2026

     Zsh Development Group

     Copyright © 1990–2026, Zsh Development Group

Texinfo / Info entry point for the Z shell manual (Yodl ‘zsh.info’
chapter order).  Man-page wrappers (‘Zsh/zsh’, ‘Zsh/zshall’, ‘Zsh/misc’)
and the separate ‘intro_zsh’ tutorial are not part of this book.

* Menu:

* Introduction::
* Roadmap::
* Invocation::
* Files::
* Shell Grammar::
* Redirection::
* Command Execution::
* Functions::
* Jobs & Signals::
* Arithmetic Evaluation::
* Conditional Expressions::
* Prompt Expansion::
* Expansion::
* Parameters::
* Options: Options<2>.
* Shell Builtin Commands::
* Zsh Line Editor::
* Completion Widgets::
* Completion System::
* Completion Using compctl::
* Zsh Modules::
* Calendar Function System::
* TCP Function System::
* Zftp Function System::
* User Contributions::
* Index::

 — The Detailed Node Listing —

Introduction

* Author::
* Availability::
* Mailing Lists::
* The Zsh FAQ::
* The Zsh Web Page::
* The Zsh Userguide::
* See Also::

Roadmap

* When the shell starts::
* Interactive Use::
* Options::
* Pattern Matching::
* General Comments on Syntax::
* Programming::

Interactive Use

* Completion::
* Extending the Line Editor::

Invocation

* Invocation: Invocation<2>.
* Compatibility::

Files

* Startup/Shutdown Files::
* Files: Files<2>.

Shell Grammar

* Simple Commands & Pipelines::
* Precommand Modifiers::
* Complex Commands::
* Alternate Forms For Complex Commands::
* Reserved Words::
* Errors::
* Comments::
* Aliasing::
* Quoting::

Aliasing

* Alias Difficulties::

Redirection

* Multios::
* Redirections with no command::

Functions

* Autoloading Functions::
* Anonymous Functions::
* Special Functions::

Special Functions

* Hook Functions::
* Trap Functions::

Jobs & Signals

* Jobs::
* Signals::

Prompt Expansion

* Expansion of Prompt Sequences::
* Simple Prompt Escapes::
* Conditional Substrings in Prompts::

Simple Prompt Escapes

* Special Characters::
* Login Information::
* Shell State::
* Date and Time::
* Visual Effects::

Expansion

* Description::
* History Expansion::
* Process Substitution::
* Parameter Expansion::
* Command Substitution::
* Arithmetic Expansion::
* Brace Expansion::
* Filename Expansion::
* Filename Generation::

History Expansion

* Overview::
* Event Designators::
* Word Designators::
* Modifiers::

Parameter Expansion

* Parameter Expansion Flags::
* Named References::
* Rules::
* Examples::

Filename Expansion

* Dynamic Named Directories::
* Static Named Directories::
* `=’ Expansion::
* Notes::

Filename Generation

* Glob Operators::
* ksh-like Glob Operators::
* Precedence::
* Globbing Flags::
* Approximate Matching::
* Recursive Globbing::
* Glob Qualifiers::

Parameters

* Description: Description<2>.
* Array Parameters::
* Positional Parameters::
* Local Parameters::
* Named References: Named References<2>.
* Parameters Set by the Shell::
* Parameters Used by the Shell::

Array Parameters

* Array Subscripts::
* Array Element Assignment::
* Subscript Flags::
* Subscript Parsing::

Options

* Specifying Options::
* Description of Options::
* Option Aliases::
* Single Letter Options::

Description of Options

* Changing Directories::
* Completion: Completion<2>.
* Expansion and Globbing::
* History::
* Initialisation::
* Input/Output::
* Job Control::
* Prompting::
* Scripts and Functions::
* Shell Emulation::
* Shell State: Shell State<2>.
* Zle::

Single Letter Options

* Default Set::
* sh/ksh Emulation Set::
* Also Note::

Zsh Line Editor

* Description: Description<3>.
* Keymaps::
* Zle Builtins::
* Zle Widgets::
* User-Defined Widgets::
* Standard Widgets::
* Terminal Extensions::
* Character Highlighting::
* Cursor Shape and Color::

Keymaps

* Reading Commands::
* Local Keymaps::

User-Defined Widgets

* Special Widgets::

Standard Widgets

* Movement::
* History Control::
* Modifying Text::
* Arguments::
* Completion: Completion<3>.
* Miscellaneous::
* Text Objects::

Completion Widgets

* Description: Description<4>.
* Completion Special Parameters::
* Completion Builtin Commands::
* Completion Condition Codes::
* Completion Matching Control::
* Completion Widget Example::

Completion System

* Description: Description<5>.
* Initialization::
* Completion System Configuration::
* Control Functions::
* Bindable Commands::
* Utility Functions::
* Completion System Variables::
* Completion Directories::

Initialization

* Use of compinit::
* Autoloaded Files::
* Functions: Functions<2>.

Completion System Configuration

* Overview: Overview<2>.
* Standard Tags::
* Standard Styles::

Completion Using compctl

* Types of completion::
* Command Flags::
* Option Flags::
* Alternative Completion::
* Extended Completion::
* Example::

Option Flags

* Simple Flags::
* Flags with Arguments::
* Control Flags::

Zsh Modules

* Description: Description<6>.
* The zsh/attr Module::
* The zsh/cap Module::
* The zsh/clone Module::
* The zsh/compctl Module::
* The zsh/complete Module::
* The zsh/complist Module::
* The zsh/computil Module::
* The zsh/curses Module::
* The zsh/datetime Module::
* The zsh/db/gdbm Module::
* The zsh/deltochar Module::
* The zsh/example Module::
* The zsh/files Module::
* The zsh/hlgroup Module::
* The zsh/langinfo Module::
* The zsh/ksh93 Module::
* The zsh/mapfile Module::
* The zsh/mathfunc Module::
* The zsh/nearcolor Module::
* The zsh/newuser Module::
* The zsh/parameter Module::
* The zsh/pcre Module::
* The zsh/param/private Module::
* The zsh/regex Module::
* The zsh/random Module::
* The zsh/sched Module::
* The zsh/net/socket Module::
* The zsh/stat Module::
* The zsh/system Module::
* The zsh/net/tcp Module::
* The zsh/termcap Module::
* The zsh/terminfo Module::
* The zsh/watch Module::
* The zsh/zftp Module::
* The zsh/zle Module::
* The zsh/zleparameter Module::
* The zsh/zprof Module::
* The zsh/zpty Module::
* The zsh/zselect Module::
* The zsh/zutil Module::

The zsh/complist Module

* Colored Completion Listings::
* Scrolling in Completion Listings::
* Menu Selection::

The zsh/curses Module

* Builtin::
* Parameters: Parameters<2>.

The zsh/ksh93 Module

* Ksh Builtins::
* Ksh Parameters::
* Future Compatibility::
* Other Differences::

The zsh/mapfile Module

* Limitations::

The zsh/random Module

* Parameters: Parameters<3>.
* Math Functions::

The zsh/net/socket Module

* Outbound Connections::
* Inbound Connections::

The zsh/system Module

* Builtins::
* Math Functions: Math Functions<2>.
* Parameters: Parameters<4>.

The zsh/net/tcp Module

* Outbound Connections: Outbound Connections<2>.
* Inbound Connections: Inbound Connections<2>.
* Closing Connections::
* Example: Example<2>.

The zsh/zftp Module

* Subcommands::
* Parameters: Parameters<5>.
* Functions: Functions<3>.
* Problems::

Calendar Function System

* Description: Description<7>.
* File and Date Formats::
* User Functions::
* Styles::
* Utility functions::
* Bugs::

File and Date Formats

* Calendar File Format::
* Date Format::
* Relative Time Format::
* Example: Example<3>.

User Functions

* Calendar System Functions::
* Glob Qualifiers: Glob Qualifiers<2>.

TCP Function System

* Description: Description<8>.
* TCP User Functions::
* TCP User-defined Functions::
* TCP Utility Functions::
* TCP User Parameters::
* TCP User-defined Parameters::
* TCP Utility Parameters::
* TCP Examples::
* TCP Bugs::

TCP User Functions

* Basic I/O::
* Session Management::
* Advanced I/O::
* `One-shot’ File Transfer::

Zftp Function System

* Description: Description<9>.
* Installation::
* Functions: Functions<4>.
* Miscellaneous Features::

Functions

* Opening a Connection::
* Directory Management::
* Status Commands::
* Retrieving Files::
* Sending Files::
* Closing the Connection::
* Session Management: Session Management<2>.
* Bookmarks::
* Other Functions::

Miscellaneous Features

* Configuration::
* Remote Globbing::
* Automatic and Temporary Reopening::
* Completion: Completion<4>.

User Contributions

* Description: Description<10>.
* Utilities::
* Remembering Recent Directories::
* Abbreviated dynamic references to directories::
* Gathering information from version control systems::
* Prompt Themes::
* ZLE Functions::
* Exception Handling::
* MIME Functions::
* Mathematical Functions::
* User Configuration Functions::
* Other Functions: Other Functions<2>.

Utilities

* Accessing On-Line Help::
* Recompiling Functions::
* Keyboard Definition::
* Dumping Shell State::
* Manipulating Hook Functions::

Remembering Recent Directories

* Installation: Installation<2>.
* Use::
* Options: Options<3>.
* Configuration: Configuration<2>.
* Use with Dynamic Directory Naming::
* Details of Directory Handling::

Abbreviated dynamic references to directories

* Usage::
* Configuration: Configuration<3>.
* Complete Example::

Gathering information from version control systems

* Quickstart::
* Configuration: Configuration<4>.
* Oddities::
* Quilt Support::
* Function Descriptions (Public API): Function Descriptions Public API.
* Variable Description::
* Hooks in vcs_info::
* Examples: Examples<2>.

Prompt Themes

* Installation: Installation<3>.
* Theme Selection::
* Utility Themes::
* Writing Themes::

ZLE Functions

* Widgets::
* Utility Functions: Utility Functions<2>.
* Styles: Styles<2>.

Other Functions

* Descriptions::
* Styles: Styles<3>.



File: zsh.info,  Node: Introduction,  Next: Roadmap,  Prev: Top,  Up: Top

1 Introduction
**************

Zsh is a UNIX command interpreter (shell) usable as an interactive login
shell and as a shell script command processor.  Of the standard shells,
zsh most closely resembles ‘ksh’ but includes many enhancements.  It
does not provide compatibility with POSIX or other shells in its default
operating mode: see ‘Compatibility’.

Zsh has command line editing, builtin spelling correction, programmable
command completion, shell functions (with autoloading), a history
mechanism, and a host of other features.

* Menu:

* Author::
* Availability::
* Mailing Lists::
* The Zsh FAQ::
* The Zsh Web Page::
* The Zsh Userguide::
* See Also::


File: zsh.info,  Node: Author,  Next: Availability,  Up: Introduction

1.1 Author
==========

Zsh was originally written by Paul Falstad.  Zsh is now maintained by
the members of the zsh-workers mailing list ‘<zsh-workers@zsh.org>’.
The development is currently coordinated by Peter Stephenson
‘<pws@zsh.org>’.  The coordinator can be contacted at
‘<coordinator@zsh.org>’, but matters relating to the code should
generally go to the mailing list.


File: zsh.info,  Node: Availability,  Next: Mailing Lists,  Prev: Author,  Up: Introduction

1.2 Availability
================

Zsh is available from the following HTTP and anonymous FTP site.

     ftp://ftp.zsh.org/pub/
     https://www.zsh.org/pub/

The up-to-date source code is available via Git from Sourceforge.  See
‘https://sourceforge.net/projects/zsh/’ for details.  A summary of
instructions for the archive can be found at
‘https://zsh.sourceforge.io/’.


File: zsh.info,  Node: Mailing Lists,  Next: The Zsh FAQ,  Prev: Availability,  Up: Introduction

1.3 Mailing Lists
=================

Zsh has several mailing lists:

‘<zsh-announce@zsh.org>’

     Announcements about releases, major changes in the shell and the
     monthly posting of the Zsh FAQ. (moderated)

‘<zsh-users@zsh.org>’

     User discussions.

‘<zsh-workers@zsh.org>’

     Hacking, development, bug reports and patches.

‘<zsh-security@zsh.org>’

     Private mailing list (the general public cannot subscribe to it)
     for discussing bug reports with security implications, i.e.,
     potential vulnerabilities.

     If you find a security problem in zsh itself, please mail this
     address.

To subscribe or unsubscribe, send mail to the associated administrative
address for the mailing list.

        * ‘<zsh-announce-subscribe@zsh.org>’

        * ‘<zsh-users-subscribe@zsh.org>’

        * ‘<zsh-workers-subscribe@zsh.org>’

        * ‘<zsh-announce-unsubscribe@zsh.org>’

        * ‘<zsh-users-unsubscribe@zsh.org>’

        * ‘<zsh-workers-unsubscribe@zsh.org>’

YOU ONLY NEED TO JOIN ONE OF THE MAILING LISTS AS THEY ARE NESTED. All
submissions to ‘zsh-announce’ are automatically forwarded to
‘zsh-users’.  All submissions to ‘zsh-users’ are automatically forwarded
to ‘zsh-workers’.

If you have problems subscribing/unsubscribing to any of the mailing
lists, send mail to ‘<listmaster@zsh.org>’.

The mailing lists are archived; the archives can be accessed via the
administrative addresses listed above.  There is also a hypertext
archive available at ‘https://www.zsh.org/mla/’.


File: zsh.info,  Node: The Zsh FAQ,  Next: The Zsh Web Page,  Prev: Mailing Lists,  Up: Introduction

1.4 The Zsh FAQ
===============

Zsh has a list of Frequently Asked Questions (FAQ), maintained by Peter
Stephenson ‘<pws@zsh.org>’.  It is regularly posted to the newsgroup
‘comp.unix.shell’ and the ‘zsh-announce’ mailing list.  The latest
version can be found at any of the Zsh FTP sites, or at
‘https://www.zsh.org/FAQ/’.  The contact address for FAQ-related matters
is ‘<faqmaster@zsh.org>’.


File: zsh.info,  Node: The Zsh Web Page,  Next: The Zsh Userguide,  Prev: The Zsh FAQ,  Up: Introduction

1.5 The Zsh Web Page
====================

Zsh has a web page which is located at ‘https://www.zsh.org/’.  The
contact address for web-related matters is ‘<webmaster@zsh.org>’.


File: zsh.info,  Node: The Zsh Userguide,  Next: See Also,  Prev: The Zsh Web Page,  Up: Introduction

1.6 The Zsh Userguide
=====================

A userguide is currently in preparation.  It is intended to complement
the manual, with explanations and hints on issues where the manual can
be cabbalistic, hierographic, or downright mystifying (for example, the
word ‘hierographic’ does not exist).  It can be viewed in its current
state at ‘https://zsh.sourceforge.io/Guide/’.  At the time of writing,
chapters dealing with startup files and their contents and the new
completion system were essentially complete.


File: zsh.info,  Node: See Also,  Prev: The Zsh Userguide,  Up: Introduction

1.7 See Also
============

‘sh(1)’, ‘csh(1)’, ‘tcsh(1)’, ‘rc(1)’, ‘bash(1)’, ‘ksh(1)’

‘IEEE Standard for information Technology - Portable Operating System
Interface (POSIX) - Part 2: Shell and Utilities’, IEEE Inc, 1993, ISBN
1-55937-255-9.


File: zsh.info,  Node: Roadmap,  Next: Invocation,  Prev: Introduction,  Up: Top

2 Roadmap
*********

The Zsh Manual, like the shell itself, is large and often complicated.
This section of the manual provides some pointers to areas of the shell
that are likely to be of particular interest to new users, and indicates
where in the rest of the manual the documentation is to be found.

* Menu:

* When the shell starts::
* Interactive Use::
* Options::
* Pattern Matching::
* General Comments on Syntax::
* Programming::


File: zsh.info,  Node: When the shell starts,  Next: Interactive Use,  Up: Roadmap

2.1 When the shell starts
=========================

When it starts, the shell reads commands from various files.  These can
be created or edited to customize the shell.  See *note Startup/Shutdown
Files: e.

If no personal initialization files exist for the current user, a
function is run to help you change some of the most common settings.  It
won’t appear if your administrator has disabled the ‘zsh/newuser’
module.  The function is designed to be self-explanatory.  You can run
it by hand with ‘autoload -Uz zsh-newuser-install; zsh-newuser-install
-f’.  See also *note User Configuration Functions: f.


File: zsh.info,  Node: Interactive Use,  Next: Options,  Prev: When the shell starts,  Up: Roadmap

2.2 Interactive Use
===================

Interaction with the shell uses the builtin Zsh Line Editor, ZLE. This
is described in detail in ‘zshzle’.

The first decision a user must make is whether to use the Emacs or Vi
editing mode as the keys for editing are substantially different.  Emacs
editing mode is probably more natural for beginners and can be selected
explicitly with the command ‘bindkey -e’.

A history mechanism for retrieving previously typed lines (most simply
with the Up or Down arrow keys) is available; note that, unlike other
shells, zsh will not save these lines when the shell exits unless you
set appropriate variables, and the number of history lines retained by
default is quite small (30 lines).  See the description of the shell
variables (referred to in the documentation as parameters) ‘HISTFILE’,
‘HISTSIZE’ and ‘SAVEHIST’ in *note Parameters Used by the Shell: 11.
Note that it’s currently only possible to read and write files saving
history when the shell is interactive, i.e.  it does not work from
scripts.

The shell now supports the UTF-8 character set (and also others if
supported by the operating system).  This is (mostly) handled
transparently by the shell, but the degree of support in terminal
emulators is variable.  There is some discussion of this in the shell
FAQ, ‘https://www.zsh.org/FAQ/’.  Note in particular that for combining
characters to be handled the option ‘COMBINING_CHARS’ needs to be set.
Because the shell is now more sensitive to the definition of the
character set, note that if you are upgrading from an older version of
the shell you should ensure that the appropriate variable, either ‘LANG’
(to affect all aspects of the shell’s operation) or ‘LC_CTYPE’ (to
affect only the handling of character sets) is set to an appropriate
value.  This is true even if you are using a single-byte character set
including extensions of ASCII such as ‘ISO-8859-1’ or ‘ISO-8859-15’.
See the description of ‘LC_CTYPE’ in *note Parameters Used by the Shell:
11.

* Menu:

* Completion::
* Extending the Line Editor::


File: zsh.info,  Node: Completion,  Next: Extending the Line Editor,  Up: Interactive Use

2.2.1 Completion
----------------

Completion is a feature present in many shells.  It allows the user to
type only a part (usually the prefix) of a word and have the shell fill
in the rest.  The completion system in zsh is programmable.  For
example, the shell can be set to complete email addresses in arguments
to the mail command from your ‘~/.abook/addressbook’; usernames,
hostnames, and even remote paths in arguments to scp, and so on.
Anything that can be written in or glued together with zsh can be the
source of what the line editor offers as possible completions.

Zsh has two completion systems, an old, so called ‘compctl’ completion
(named after the builtin command that serves as its complete and only
user interface), and a new one, referred to as ‘compsys’, organized as
library of builtin and user-defined functions.  The two systems differ
in their interface for specifying the completion behavior.  The new
system is more customizable and is supplied with completions for many
commonly used commands; it is therefore to be preferred.

The completion system must be enabled explicitly when the shell starts.
For more information see ‘zshcompsys’.


File: zsh.info,  Node: Extending the Line Editor,  Prev: Completion,  Up: Interactive Use

2.2.2 Extending the Line Editor
-------------------------------

Apart from completion, the line editor is highly extensible by means of
shell functions.  Some useful functions are provided with the shell;
they provide facilities such as:

‘insert-composed-char’

     composing characters not found on the keyboard

‘match-words-by-style’

     configuring what the line editor considers a word when moving or
     deleting by word

‘history-beginning-search-backward-end’, etc.

     alternative ways of searching the shell history

‘replace-string’, ‘replace-pattern’

     functions for replacing strings or patterns globally in the command
     line

‘edit-command-line’

     edit the command line with an external editor.

See *note ZLE Functions: 14. for descriptions of these.


File: zsh.info,  Node: Options,  Next: Pattern Matching,  Prev: Interactive Use,  Up: Roadmap

2.3 Options
===========

The shell has a large number of options for changing its behaviour.
These cover all aspects of the shell; browsing the full documentation is
the only good way to become acquainted with the many possibilities.  See
‘zshoptions’.


File: zsh.info,  Node: Pattern Matching,  Next: General Comments on Syntax,  Prev: Options,  Up: Roadmap

2.4 Pattern Matching
====================

The shell has a rich set of patterns which are available for file
matching (described in the documentation as ‘filename generation’ and
also known for historical reasons as ‘globbing’) and for use when
programming.  These are described in *note Filename Generation: 17.

Of particular interest are the following patterns that are not commonly
supported by other systems of pattern matching:

‘**’

     for matching over multiple directories

‘|’

     for matching either of two alternatives

‘~’, ‘^’

     the ability to exclude patterns from matching when the
     ‘EXTENDED_GLOB’ option is set

‘(’…‘)’

     glob qualifiers, included in parentheses at the end of the pattern,
     which select files by type (such as directories) or attribute (such
     as size).


File: zsh.info,  Node: General Comments on Syntax,  Next: Programming,  Prev: Pattern Matching,  Up: Roadmap

2.5 General Comments on Syntax
==============================

Although the syntax of zsh is in ways similar to the Korn shell, and
therefore more remotely to the original UNIX shell, the Bourne shell,
its default behaviour does not entirely correspond to those shells.
General shell syntax is introduced in *note Shell Grammar: 19.

One commonly encountered difference is that variables substituted onto
the command line are not split into words.  See the description of the
shell option ‘SH_WORD_SPLIT’ in *note Parameter Expansion: 1a.  In zsh,
you can either explicitly request the splitting (e.g.  ‘${=foo}’) or use
an array when you want a variable to expand to more than one word.  See
*note Array Parameters: 1b.


File: zsh.info,  Node: Programming,  Prev: General Comments on Syntax,  Up: Roadmap

2.6 Programming
===============

The most convenient way of adding enhancements to the shell is typically
by writing a shell function and arranging for it to be autoloaded.
Functions are described in *note Functions: 1d.  Users changing from the
C shell and its relatives should notice that aliases are less used in
zsh as they don’t perform argument substitution, only simple text
replacement.

A few general functions, other than those for the line editor described
above, are provided with the shell and are described in ‘zshcontrib’.
Features include:

‘promptinit’

     a prompt theme system for changing prompts easily, see *note Prompt
     Themes: 1e.

‘zsh-mime-setup’

     a MIME-handling system which dispatches commands according to the
     suffix of a file as done by graphical file managers

‘zcalc’

     a calculator

‘zargs’

     a version of ‘xargs’ that makes the ‘find’ command redundant

‘zmv’

     a command for renaming files by means of shell patterns.


File: zsh.info,  Node: Invocation,  Next: Files,  Prev: Roadmap,  Up: Top

3 Invocation
************

* Menu:

* Invocation: Invocation<2>.
* Compatibility::


File: zsh.info,  Node: Invocation<2>,  Next: Compatibility,  Up: Invocation

3.1 Invocation
==============

The following flags are interpreted by the shell when invoked to
determine where the shell will read commands from:

‘-c’

     Take the first argument as a command to execute, rather than
     reading commands from a script or standard input.  If any further
     arguments are given, the first one is assigned to ‘$0’, rather than
     being used as a positional parameter.

‘-i’

     Force shell to be interactive.  It is still possible to specify a
     script to execute.

‘-s’

     Force shell to read commands from the standard input.  If the ‘-s’
     flag is not present and an argument is given, the first argument is
     taken to be the pathname of a script to execute.

If there are any remaining arguments after option processing, and
neither of the options ‘-c’ or ‘-s’ was supplied, the first argument is
taken as the file name of a script containing shell commands to be
executed.  If the option ‘PATH_SCRIPT’ is set, and the file name does
not contain a directory path (i.e.  there is no ‘/’ in the name), first
the current directory and then the command path given by the variable
‘PATH’ are searched for the script.  If the option is not set or the
file name contains a ‘/’ it is used directly.

After the first one or two arguments have been appropriated as described
above, the remaining arguments are assigned to the positional
parameters.

For further options, which are common to invocation and the ‘set’
builtin, see ‘zshoptions’.

The long option ‘--emulate’ followed (in a separate word) by an
emulation mode may be passed to the shell.  The emulation modes are
those described for the ‘emulate’ builtin, see ‘zshbuiltins’.  The
‘--emulate’ option must precede any other options (which might otherwise
be overridden), but following options are honoured, so may be used to
modify the requested emulation mode.  Note that certain extra steps are
taken to ensure a smooth emulation when this option is used compared
with the ‘emulate’ command within the shell: for example, variables that
conflict with POSIX usage such as ‘path’ are not defined within the
shell.

Options may be specified by name using the ‘-o’ option.  ‘-o’ acts like
a single-letter option, but takes a following string as the option name.
For example,

      zsh -x -o shwordsplit scr

runs the script ‘scr’, setting the ‘XTRACE’ option by the corresponding
letter ‘-x’ and the ‘SH_WORD_SPLIT’ option by name.  Options may be
turned ‘off’ by name by using ‘+o’ instead of ‘-o’.  ‘-o’ can be stacked
up with preceding single-letter options, so for example ‘-xo
shwordsplit’ or ‘-xoshwordsplit’ is equivalent to ‘-x -o shwordsplit’.

Options may also be specified by name in GNU long option style,
‘--’OPTION-NAME.  When this is done, ‘-’ characters in the option name
are permitted: they are translated into ‘_’, and thus ignored.  So, for
example, ‘zsh --sh-word-split’ invokes zsh with the ‘SH_WORD_SPLIT’
option turned on.  Like other option syntaxes, options can be turned off
by replacing the initial ‘-’ with a ‘+’; thus ‘+-sh-word-split’ is
equivalent to ‘--no-sh-word-split’.  Unlike other option syntaxes,
GNU-style long options cannot be stacked with any other options, so for
example ‘-x-shwordsplit’ is an error, rather than being treated like ‘-x
--shwordsplit’.

The special GNU-style option ‘--version’ is handled; it sends to
standard output the shell’s version information, then exits
successfully.  ‘--help’ is also handled; it sends to standard output a
list of options that can be used when invoking the shell, then exits
successfully.

Option processing may be finished, allowing following arguments that
start with ‘-’ or ‘+’ to be treated as normal arguments, in two ways.
Firstly, a lone ‘-’ (or ‘+’) as an argument by itself ends option
processing.  Secondly, a special option ‘--’ (or ‘+-’), which may be
specified on its own (which is the standard POSIX usage) or may be
stacked with preceding options (so ‘-x-’ is equivalent to ‘-x --’).
Options are not permitted to be stacked after ‘--’ (so ‘-x-f’ is an
error), but note the GNU-style option form discussed above, where
‘--shwordsplit’ is permitted and does not end option processing.

Except when the ‘sh’/‘ksh’ emulation single-letter options are in
effect, the option ‘-b’ (or ‘+b’) ends option processing.  ‘-b’ is like
‘--’, except that further single-letter options can be stacked after the
‘-b’ and will take effect as normal.


File: zsh.info,  Node: Compatibility,  Prev: Invocation<2>,  Up: Invocation

3.2 Compatibility
=================

Zsh tries to emulate ‘sh’ or ‘ksh’ when it is invoked as ‘sh’ or ‘ksh’
respectively; more precisely, it looks at the first letter of the name
by which it was invoked, and if that is ‘b’, ‘s’ or ‘k’ it will emulate
‘sh’ or ‘ksh’.  Furthermore, if invoked as ‘su’ (which happens on
certain systems when the shell is executed by the ‘su’ command), the
shell will try to find an alternative name from the ‘SHELL’ environment
variable and perform emulation based on that.

In ‘sh’ and ‘ksh’ compatibility modes the following parameters are not
special and not initialized by the shell: ‘ARGC’, ‘argv’, ‘cdpath’,
‘fignore’, ‘fpath’, ‘HISTCHARS’, ‘mailpath’, ‘MANPATH’, ‘manpath’,
‘path’, ‘prompt’, ‘PROMPT’, ‘PROMPT2’, ‘PROMPT3’, ‘PROMPT4’, ‘psvar’,
‘status’.

The usual zsh startup/shutdown scripts are not executed.  Login shells
source ‘/etc/profile’ followed by ‘$HOME/.profile’.  If the ‘ENV’
environment variable is set on invocation, ‘$ENV’ is sourced after the
profile scripts.  The value of ‘ENV’ is subjected to parameter
expansion, command substitution, and arithmetic expansion before being
interpreted as a pathname.  Note that the ‘PRIVILEGED’ option also
affects the execution of startup files.

The following options are set if the shell is invoked as ‘sh’ or ‘ksh’:
‘NO_BAD_PATTERN’, ‘NO_BANG_HIST’, ‘NO_BG_NICE’, ‘NO_EQUALS’,
‘NO_FUNCTION_ARGZERO’, ‘GLOB_SUBST’, ‘NO_GLOBAL_EXPORT’, ‘NO_HUP’,
‘INTERACTIVE_COMMENTS’, ‘KSH_ARRAYS’, ‘NO_MULTIOS’, ‘NO_NOMATCH’,
‘NO_NOTIFY’, ‘POSIX_BUILTINS’, ‘NO_PROMPT_PERCENT’, ‘RM_STAR_SILENT’,
‘SH_FILE_EXPANSION’, ‘SH_GLOB’, ‘SH_OPTION_LETTERS’, ‘SH_WORD_SPLIT’.
Additionally the ‘BSD_ECHO’ and ‘IGNORE_BRACES’ options are set if zsh
is invoked as ‘sh’.  Also, the ‘KSH_OPTION_PRINT’, ‘LOCAL_OPTIONS’,
‘PROMPT_BANG’, ‘PROMPT_SUBST’ and ‘SINGLE_LINE_ZLE’ options are set if
zsh is invoked as ‘ksh’.

Please note that, whilst reasonable efforts are taken to address
incompatibilities when they arise, zsh does not guarantee complete
emulation of other shells, nor POSIX compliance.  For more information
on the differences between zsh and other shells, please refer to
chapter 2 of the shell FAQ, ‘https://www.zsh.org/FAQ/’.


File: zsh.info,  Node: Files,  Next: Shell Grammar,  Prev: Invocation,  Up: Top

4 Files
*******

* Menu:

* Startup/Shutdown Files::
* Files: Files<2>.


File: zsh.info,  Node: Startup/Shutdown Files,  Next: Files<2>,  Up: Files

4.1 Startup/Shutdown Files
==========================

Commands are first read from ‘/etc/zshenv’; this cannot be overridden.
Subsequent behaviour is modified by the ‘RCS’ and ‘GLOBAL_RCS’ options;
the former affects all startup files, while the second only affects
global startup files (those shown here with a path starting with a ‘/’).
If one of the options is unset at any point, any subsequent startup
file(s) of the corresponding type will not be read.  It is also possible
for a file in ‘$ZDOTDIR’ to re-enable ‘GLOBAL_RCS’.  Both ‘RCS’ and
‘GLOBAL_RCS’ are set by default.

Commands are then read from ‘$ZDOTDIR/.zshenv’.  ..  index:: single:
LOGIN, use of; Program

If the shell is a login shell, commands are read from ‘/etc/zprofile’
and then ‘$ZDOTDIR/.zprofile’.  ..  index:: single: zshrc; Command

Then, if the shell is interactive, commands are read from ‘/etc/zshrc’
and then ‘$ZDOTDIR/.zshrc’.  ..  index:: single: zlogin; Command

Finally, if the shell is a login shell, ‘/etc/zlogin’ and
‘$ZDOTDIR/.zlogin’ are read.

When a login shell exits, the files ‘$ZDOTDIR/.zlogout’ and then
‘/etc/zlogout’ are read.  This happens with either an explicit exit via
the ‘exit’ or ‘logout’ commands, or an implicit exit by reading
end-of-file from the terminal.  However, if the shell terminates due to
‘exec’’ing another process, the logout files are not read.  These are
also affected by the ‘RCS’ and ‘GLOBAL_RCS’ options.  Note also that the
‘RCS’ option affects the saving of history files, i.e.  if ‘RCS’ is
unset when the shell exits, no history file will be saved.

If ‘ZDOTDIR’ is unset, ‘HOME’ is used instead.  Files listed above as
being in ‘/etc’ may be in another directory, depending on the
installation.

As ‘/etc/zshenv’ is run for all instances of zsh, it is important that
it be kept as small as possible.  In particular, it is a good idea to
put code that does not need to be run for every single shell behind a
test of the form ‘if [[ -o rcs ]]; then ...’ so that it will not be
executed when zsh is invoked with the ‘-f’ option.

Any of these files may be pre-compiled with the ‘zcompile’ builtin
command (see ‘zshbuiltins’).  If a compiled file exists (named for the
original file plus the ‘.zwc’ extension) and it is newer than the
original file, the compiled file will be used instead.


File: zsh.info,  Node: Files<2>,  Prev: Startup/Shutdown Files,  Up: Files

4.2 Files
=========


File: zsh.info,  Node: Shell Grammar,  Next: Redirection,  Prev: Files,  Up: Top

5 Shell Grammar
***************

* Menu:

* Simple Commands & Pipelines::
* Precommand Modifiers::
* Complex Commands::
* Alternate Forms For Complex Commands::
* Reserved Words::
* Errors::
* Comments::
* Aliasing::
* Quoting::


File: zsh.info,  Node: Simple Commands & Pipelines,  Next: Precommand Modifiers,  Up: Shell Grammar

5.1 Simple Commands & Pipelines
===============================

A ‘simple command’ is a sequence of optional parameter assignments
followed by blank-separated words, with optional redirections
interspersed.  For a description of assignment, see the beginning of
‘zshparam’.

The first word is the command to be executed, and the remaining words,
if any, are arguments to the command.  If a command name is given, the
parameter assignments modify the environment of the command when it is
executed.  The value of a simple command is its exit status, or 128 plus
the signal number if terminated by a signal.  For example,

      echo foo

is a simple command with arguments.

A ‘pipeline’ is either a simple command, or a sequence of two or more
simple commands where each command is separated from the next by ‘|’ or
‘|&’.  Where commands are separated by ‘|’, the standard output of the
first command is connected to the standard input of the next.  ‘|&’ is
shorthand for ‘2>&1 |’, which connects both the standard output and the
standard error of the command to the standard input of the next.  The
value of a pipeline is the value of the last command, unless the
pipeline is preceded by ‘!’ in which case the value is the logical
inverse of the value of the last command.  For example,

      echo foo | sed 's/foo/bar/'

is a pipeline, where the output (‘foo’ plus a newline) of the first
command will be passed to the input of the second.

If a pipeline is preceded by ‘coproc’, it is executed as a coprocess; a
two-way pipe is established between it and the parent shell.  The shell
can read from or write to the coprocess by means of the ‘>&p’ and ‘<&p’
redirection operators or with ‘print -p’ and ‘read -p’.  A pipeline
cannot be preceded by both ‘coproc’ and ‘!’.  If job control is active,
the coprocess can be treated in other than input and output as an
ordinary background job.

A ‘sublist’ is either a single pipeline, or a sequence of two or more
pipelines separated by ‘&&’ or ‘||’.  If two pipelines are separated by
‘&&’, the second pipeline is executed only if the first succeeds
(returns a zero status).  If two pipelines are separated by ‘||’, the
second is executed only if the first fails (returns a nonzero status).
Both operators have equal precedence and are left associative.  The
value of the sublist is the value of the last pipeline executed.  For
example,

      dmesg | grep panic && print yes

is a sublist consisting of two pipelines, the second just a simple
command which will be executed if and only if the ‘grep’ command returns
a zero status.  If it does not, the value of the sublist is that return
status, else it is the status returned by the ‘print’ (almost certainly
zero).

A ‘list’ is a sequence of zero or more sublists, in which each sublist
is terminated by ‘;’, ‘&’, ‘&|’, ‘&!’, or a newline.  This terminator
may optionally be omitted from the last sublist in the list when the
list appears as a complex command inside ‘(...)’ or ‘{...}’.  When a
sublist is terminated by ‘;’ or newline, the shell waits for it to
finish before executing the next sublist.  If a sublist is terminated by
a ‘&’, ‘&|’, or ‘&!’, the shell executes the last pipeline in it in the
background, and does not wait for it to finish (note the difference from
other shells which execute the whole sublist in the background).  A
backgrounded pipeline returns a status of zero.

More generally, a list can be seen as a set of any shell commands
whatsoever, including the complex commands below; this is implied
wherever the word ‘list’ appears in later descriptions.  For example,
the commands in a shell function form a special sort of list.


File: zsh.info,  Node: Precommand Modifiers,  Next: Complex Commands,  Prev: Simple Commands & Pipelines,  Up: Shell Grammar

5.2 Precommand Modifiers
========================

With the exception of ‘nocorrect’, which is a reserved word that affects
further parsing when it is found in command position, each of the
following builtin commands is a ‘precommand modifier’ which may precede
a simple command to alter how that command is interpreted.

‘-’

     The command is executed with a ‘-’ prepended to its ‘argv[0]’
     string.

‘builtin’

     The command word is taken to be the name of a builtin command,
     rather than a shell function or external command.

‘command’ [ ‘-pvV’ ]

     The command word is taken to be the name of an external command,
     rather than a shell function or builtin.  If the ‘POSIX_BUILTINS’
     option is set, builtins will also be executed but certain special
     properties of them are suppressed.  The ‘-p’ flag causes a default
     path to be searched instead of that in ‘$path’.  With the ‘-v’
     flag, ‘command’ is similar to ‘whence’ and with ‘-V’, it is
     equivalent to ‘whence -v’.

‘exec’ [ ‘-cl’ ] [ ‘-a’ ARGV0 ]

     The following command together with any arguments is run in place
     of the current process, rather than as a sub-process.  The shell
     does not fork and is replaced.  The shell does not invoke
     ‘TRAPEXIT’, nor does it source ‘zlogout’ files.  The options are
     provided for compatibility with other shells.

     The ‘-c’ option clears the environment.

     The ‘-l’ option is equivalent to the ‘-’ precommand modifier, to
     treat the replacement command as a login shell; the command is
     executed with a ‘-’ prepended to its ‘argv[0]’ string.  This flag
     has no effect if used together with the ‘-a’ option.

     The ‘-a’ option is used to specify explicitly the ‘argv[0]’ string
     (the name of the command as seen by the process itself) to be used
     by the replacement command and is directly equivalent to setting a
     value for the ‘ARGV0’ environment variable.

‘nocorrect’

     Spelling correction is not done on any of the words.  This must
     appear before any other precommand modifier, as it is interpreted
     immediately, before any parsing is done.  It has no effect in
     non-interactive shells.

‘noglob’

     Filename generation (globbing) is not performed on any of the
     words.


File: zsh.info,  Node: Complex Commands,  Next: Alternate Forms For Complex Commands,  Prev: Precommand Modifiers,  Up: Shell Grammar

5.3 Complex Commands
====================

A ‘complex command’ in zsh is one of the following:

‘if’ LIST ‘then’ LIST [ ‘elif’ LIST ‘then’ LIST ] … [ ‘else’ LIST ] ‘fi’

     The ‘if’ LIST is executed, and if it returns a zero exit status,
     the ‘then’ LIST is executed.  Otherwise, the ‘elif’ LIST is
     executed and if its status is zero, the ‘then’ LIST is executed.
     If each ‘elif’ LIST returns nonzero status, the ‘else’ LIST is
     executed.

‘for’ NAME … [ ‘in’ WORD … ] TERM ‘do’ LIST ‘done’

     Expand the list of WORDs, and set the parameter NAME to each of
     them in turn, executing LIST each time.  If the ‘in’ WORD is
     omitted, use the positional parameters instead of the WORDs.  If
     any NAME has been declared as a named reference, the corresponding
     WORD is treated as the name of a parameter and NAME is made a
     reference to that.  Note that for the positional parameters, this
     treats the value of each positional as parameter name rather than
     creating a reference to the position.

     The TERM consists of one or more newline or ‘;’ which terminate the
     WORDs, and are optional when the ‘in’ WORD is omitted.

     More than one parameter NAME can appear before the list of WORDs.
     If N NAMEs are given, then on each execution of the loop the next N
     WORDs are assigned to the corresponding parameters.  If there are
     more NAMEs than remaining WORDs, the remaining parameters are each
     set to the empty string.  Execution of the loop ends when there is
     no remaining WORD to assign to the first NAME.  It is only possible
     for ‘in’ to appear as the first NAME in the list, else it will be
     treated as marking the end of the list.

‘for ((’ [EXPR1] ‘;’ [EXPR2] ‘;’ [EXPR3] ‘)) do’ LIST ‘done’

     The arithmetic expression EXPR1 is evaluated first (see ‘Arithmetic
     Evaluation’).  The arithmetic expression EXPR2 is repeatedly
     evaluated until it evaluates to zero and when non-zero, LIST is
     executed and the arithmetic expression EXPR3 evaluated.  If any
     expression is omitted, then it behaves as if it evaluated to 1.

‘while’ LIST ‘do’ LIST ‘done’

     Execute the ‘do’ LIST as long as the ‘while’ LIST returns a zero
     exit status.

‘until’ LIST ‘do’ LIST ‘done’

     Execute the ‘do’ LIST as long as ‘until’ LIST returns a nonzero
     exit status.

‘repeat’ WORD ‘do’ LIST ‘done’

     WORD is expanded and treated as an arithmetic expression, which
     must evaluate to a number N.  LIST is then executed N times.

     The ‘repeat’ syntax is disabled by default when the shell starts in
     a mode emulating another shell.  It can be enabled with the command
     ‘enable -r repeat’

‘case’ WORD ‘in’ [ [‘(’] PATTERN [ ‘|’ PATTERN ] … ‘)’ LIST (‘;;|;&|;|’)
] … ‘esac’

     Execute the LIST associated with the first PATTERN that matches
     WORD, if any.  The form of the patterns is the same as that used
     for filename generation.  See *note Filename Generation: 17.

     Note further that, unless the ‘SH_GLOB’ option is set, the whole
     pattern with alternatives is treated by the shell as equivalent to
     a group of patterns within parentheses, although white space may
     appear about the parentheses and the vertical bar and will be
     stripped from the pattern at those points.  White space may appear
     elsewhere in the pattern; this is not stripped.  If the ‘SH_GLOB’
     option is set, so that an opening parenthesis can be unambiguously
     treated as part of the case syntax, the expression is parsed into
     separate words and these are treated as strict alternatives (as in
     other shells).

     If the LIST that is executed is terminated with ‘;&’ rather than
     ‘;;’, the following list is also executed.  The rule for the
     terminator of the following list ‘;;’, ‘;&’ or ‘;|’ is applied
     unless the ‘esac’ is reached.

     If the LIST that is executed is terminated with ‘;|’ the shell
     continues to scan the PATTERNs looking for the next match,
     executing the corresponding LIST, and applying the rule for the
     corresponding terminator ‘;;’, ‘;&’ or ‘;|’.  Note that WORD is not
     re-expanded; all applicable PATTERNs are tested with the same WORD.

‘select’ NAME [ ‘in’ WORD … TERM ] ‘do’ LIST ‘done’

     where TERM is one or more newline or ‘;’ to terminate the WORDs.
     ..  index:: single: REPLY, use of; Variable

     Print the set of WORDs, each preceded by a number.  If the ‘in’
     WORD is omitted, use the positional parameters.  The ‘PROMPT3’
     prompt is printed and a line is read from the line editor if the
     shell is interactive and that is active, or else standard input.
     If this line consists of the number of one of the listed WORDs,
     then the parameter NAME is set to the WORD corresponding to this
     number.  If this line is empty, the selection list is printed
     again.  Otherwise, the value of the parameter NAME is set to null.
     The contents of the line read from standard input is saved in the
     parameter ‘REPLY’.  LIST is executed for each selection until a
     break or end-of-file is encountered.

‘(’ LIST ‘)’

     Execute LIST in a subshell.  Traps set by the ‘trap’ builtin are
     reset to their default values while executing LIST; an exception is
     that ignored signals will continue to be ignored if the option
     ‘POSIXTRAPS’ is set.

‘{’ LIST ‘}’

     Execute LIST.

‘{’ TRY-LIST ‘} always {’ ALWAYS-LIST ‘}’

     First execute TRY-LIST.  Regardless of errors, or ‘break’ or
     ‘continue’ commands encountered within TRY-LIST, execute
     ALWAYS-LIST.  Execution then continues from the result of the
     execution of TRY-LIST; in other words, any error, or ‘break’ or
     ‘continue’ command is treated in the normal way, as if ALWAYS-LIST
     were not present.  The two chunks of code are referred to as the
     ‘try block’ and the ‘always block’.

     Optional newlines or semicolons may appear after the ‘always’;
     note, however, that they may ‘not’ appear between the preceding
     closing brace and the ‘always’.

     An ‘error’ in this context is a condition such as a syntax error
     which causes the shell to abort execution of the current function,
     script, or list.  Syntax errors encountered while the shell is
     parsing the code do not cause the ALWAYS-LIST to be executed.  For
     example, an erroneously constructed ‘if’ block in TRY-LIST would
     cause the shell to abort during parsing, so that ALWAYS-LIST would
     not be executed, while an erroneous substitution such as ‘${*foo*}’
     would cause a run-time error, after which ALWAYS-LIST would be
     executed.

     An error condition can be tested and reset with the special integer
     variable ‘TRY_BLOCK_ERROR’.  Outside an ALWAYS-LIST the value is
     irrelevant, but it is initialised to ‘-1’.  Inside ALWAYS-LIST, the
     value is 1 if an error occurred in the TRY-LIST, else 0.  If
     ‘TRY_BLOCK_ERROR’ is set to 0 during the ALWAYS-LIST, the error
     condition caused by the TRY-LIST is reset, and shell execution
     continues normally after the end of ALWAYS-LIST.  Altering the
     value during the TRY-LIST is not useful (unless this forms part of
     an enclosing ‘always’ block).

     Regardless of ‘TRY_BLOCK_ERROR’, after the end of ALWAYS-LIST the
     normal shell status ‘$?’ is the value returned from TRY-LIST.  This
     will be non-zero if there was an error, even if ‘TRY_BLOCK_ERROR’
     was set to zero.

     The following executes the given code, ignoring any errors it
     causes.  This is an alternative to the usual convention of
     protecting code by executing it in a subshell.

           {
               # code which may cause an error
             } always {
               # This code is executed regardless of the error.
               (( TRY_BLOCK_ERROR = 0 ))
           }
           # The error condition has been reset.

     When a ‘try’ block occurs outside of any function, a ‘return’ or a
     ‘exit’ encountered in TRY-LIST does ‘not’ cause the execution of
     ALWAYS-LIST.  Instead, the shell exits immediately after any ‘EXIT’
     trap has been executed.  Otherwise, a ‘return’ command encountered
     in TRY-LIST will cause the execution of ALWAYS-LIST, just like
     ‘break’ and ‘continue’.

‘function’ [ ‘-T’ ] WORD … [ ‘()’ ] [ TERM ] ‘{’ LIST ‘}’

WORD … ‘()’ [ TERM ] ‘{’ LIST ‘}’

WORD … ‘()’ [ TERM ] COMMAND

     where TERM is one or more newline or ‘;’.  Define a function which
     is referenced by any one of WORD.  Normally, only one WORD is
     provided; multiple WORDs are usually only useful for setting traps.
     The body of the function is the LIST between the ‘{’ and ‘}’.  See
     ‘Functions’.

     The options of ‘function’ have the following meanings:

     ‘-T’

          Enable tracing for this function, as though with ‘functions
          -T’.  See the documentation of the ‘-f’ option to the
          ‘typeset’ builtin, in *note Shell Builtin Commands: 2c.

     If the option ‘SH_GLOB’ is set for compatibility with other shells,
     then whitespace may appear between the left and right parentheses
     when there is a single WORD; otherwise, the parentheses will be
     treated as forming a globbing pattern in that case.

     In any of the forms above, a redirection may appear outside the
     function body, for example

           func() { ... } 2>&1

     The redirection is stored with the function and applied whenever
     the function is executed.  Any variables in the redirection are
     expanded at the point the function is executed, but outside the
     function scope.

‘time’ [ PIPELINE ]

     The PIPELINE is executed, and timing statistics are reported on the
     standard error in the form specified by the ‘TIMEFMT’ parameter.
     If PIPELINE is omitted, print statistics about the shell process
     and its children.

‘[[’ EXP ‘]]’

     Evaluates the conditional expression EXP and return a zero exit
     status if it is true.  See ‘Conditional Expressions’ for a
     description of EXP.


File: zsh.info,  Node: Alternate Forms For Complex Commands,  Next: Reserved Words,  Prev: Complex Commands,  Up: Shell Grammar

5.4 Alternate Forms For Complex Commands
========================================

Many of zsh’s complex commands have alternate forms.  These are
non-standard and are likely not to be obvious even to seasoned shell
programmers; they should not be used anywhere that portability of shell
code is a concern.

The short versions below only work if SUBLIST is of the form ‘{’ LIST
‘}’ or if the ‘SHORT_LOOPS’ option is set.  For the ‘if’, ‘while’ and
‘until’ commands, in both these cases the test part of the loop must
also be suitably delimited, such as by ‘[[’ … ‘]]’ or ‘((’ … ‘))’, else
the end of the test will not be recognized.  For the ‘for’, ‘repeat’,
‘case’ and ‘select’ commands no such special form for the arguments is
necessary, but the other condition (the special form of SUBLIST or use
of the ‘SHORT_LOOPS’ option) still applies.  The ‘SHORT_REPEAT’ option
is available to enable the short version only for the ‘repeat’ command.

‘if’ LIST ‘{’ LIST ‘}’ [ ‘elif’ LIST ‘{’ LIST ‘}’ ] … [ ‘else {’ LIST
‘}’ ]

     An alternate form of ‘if’.  The rules mean that

           if [[ -o ignorebraces ]] {
             print yes
           }

     works, but

           if true {  # Does not work!
             print yes
           }

     does ‘not’, since the test is not suitably delimited.

‘if’ LIST SUBLIST

     A short form of the alternate ‘if’.  The same limitations on the
     form of LIST apply as for the previous form.

‘for’ NAME … ‘(’ WORD … ‘)’ SUBLIST

     A short form of ‘for’.

‘for’ NAME … [ ‘in’ WORD … ] TERM SUBLIST

     where TERM is at least one newline or ‘;’.  Another short form of
     ‘for’.

‘for ((’ [EXPR1] ‘;’ [EXPR2] ‘;’ [EXPR3] ‘))’ SUBLIST

     A short form of the arithmetic ‘for’ command.

‘foreach’ NAME … ‘(’ WORD … ‘)’ LIST ‘end’

     Another form of ‘for’.

‘while’ LIST ‘{’ LIST ‘}’

     An alternative form of ‘while’.  Note the limitations on the form
     of LIST mentioned above.

‘until’ LIST ‘{’ LIST ‘}’

     An alternative form of ‘until’.  Note the limitations on the form
     of LIST mentioned above.

‘repeat’ WORD SUBLIST

     This is a short form of ‘repeat’.

‘case’ WORD ‘{’ [ [‘(’] PATTERN [ ‘|’ PATTERN ] … ‘)’ LIST (‘;;|;&|;|’)
] … ‘}’

     An alternative form of ‘case’.

‘select’ NAME [ ‘in’ WORD … TERM ] SUBLIST

     where TERM is at least one newline or ‘;’.  A short form of
     ‘select’.

‘function’ WORD … [ ‘()’ ] [ TERM ] SUBLIST

     This is a short form of ‘function’.


File: zsh.info,  Node: Reserved Words,  Next: Errors,  Prev: Alternate Forms For Complex Commands,  Up: Shell Grammar

5.5 Reserved Words
==================

The following words are recognized as reserved words when used as the
first word of a command unless quoted or disabled using ‘disable -r’:

‘do done esac then elif else fi for case if while function repeat time
until select coproc nocorrect foreach end ! [[ { } declare export float
integer local readonly typeset’

Additionally, ‘}’ is recognized in any position if neither the
‘IGNORE_BRACES’ option nor the ‘IGNORE_CLOSE_BRACES’ option is set.


File: zsh.info,  Node: Errors,  Next: Comments,  Prev: Reserved Words,  Up: Shell Grammar

5.6 Errors
==========

Certain errors are treated as fatal by the shell: in an interactive
shell, they cause control to return to the command line, and in a
non-interactive shell they cause the shell to be aborted.  In older
versions of zsh, a non-interactive shell running a script would not
abort completely, but would resume execution at the next command to be
read from the script, skipping the remainder of any functions or shell
constructs such as loops or conditions; this somewhat illogical
behaviour can be recovered by setting the option ‘CONTINUE_ON_ERROR’.

Fatal errors found in non-interactive shells include:

        * Failure to parse shell options passed when invoking the shell

        * Failure to change options with the ‘set’ builtin

        * Parse errors of all sorts, including failures to parse

     mathematical expressions * Failures to set or modify variable
     behaviour with ‘typeset’, ‘local’, ‘declare’, ‘export’, ‘integer’,
     ‘float’ * Execution of incorrectly positioned loop control
     structures (‘continue’, ‘break’) * Attempts to use regular
     expression with no regular expression module available * Failure to
     create a pipe needed for a pipeline * Failure to create a multio *
     Failure to autoload a module needed for a declared shell feature *
     Errors creating command or process substitutions * Syntax errors in
     glob qualifiers * File generation errors where not caught by the
     option ‘BAD_PATTERN’ * All bad patterns used for matching within
     case statements * File generation failures where not caused by
     ‘NOMATCH’ or similar options * All file generation errors where the
     pattern was used to create a multio * Memory errors where detected
     by the shell * Invalid subscripts to shell variables * Attempts to
     assign read-only variables * Logical errors with variables such as
     assignment to the wrong type * Use of invalid variable names *
     Errors in variable substitution syntax * Failure to convert
     characters in ‘$'...'’ expressions

If the ‘POSIX_BUILTINS’ option is set, more errors associated with shell
builtin commands are treated as fatal, as specified by the POSIX
standard.


File: zsh.info,  Node: Comments,  Next: Aliasing,  Prev: Errors,  Up: Shell Grammar

5.7 Comments
============

In non-interactive shells, or in interactive shells with the
‘INTERACTIVE_COMMENTS’ option set, a word beginning with the third
character of the ‘histchars’ parameter (‘#’ by default) causes that word
and all the following characters up to a newline to be ignored.


File: zsh.info,  Node: Aliasing,  Next: Quoting,  Prev: Comments,  Up: Shell Grammar

5.8 Aliasing
============

Every eligible ‘word’ in the shell input is checked to see if there is
an alias defined for it.  If so, it is replaced by the text of the alias
if it is in command position (if it could be the first word of a simple
command), or if the alias is global.  If the replacement text ends with
a space, the next word in the shell input is always eligible for
purposes of alias expansion.

It is an error for the function name, WORD, in the sh-compatible
function definition syntax WORD ‘()’ … to be a word that resulted from
alias expansion, unless the ‘ALIAS_FUNC_DEF’ option is set.

An alias is defined using the ‘alias’ builtin; global aliases may be
defined using the ‘-g’ option to that builtin.

A ‘word’ is defined as:

        * Any plain string or glob pattern

        * Any quoted string, using any quoting method (note that the
          quotes

     must be part of the alias definition for this to be eligible) * Any
     parameter reference or command substitution * Any series of the
     foregoing, concatenated without whitespace or other tokens between
     them * Any reserved word (‘case’, ‘do’, ‘else’, etc.)  * With
     global aliasing, any command separator, any redirection operator,
     and ‘(’ or ‘)’ when not part of a glob pattern

Alias expansion is done on the shell input before any other expansion
except history expansion.  Therefore, if an alias is defined for the
word ‘foo’, alias expansion may be avoided by quoting part of the word,
e.g.  ‘\foo’.  Any form of quoting works, although there is nothing to
prevent an alias being defined for the quoted form such as ‘\foo’ as
well.

In particular, note that quoting must be used when using ‘unalias’ to
remove global aliases:

      % alias -g foo=bar
      % unalias foo
      unalias: no such hash table element: bar
      % unalias \foo
      %

When ‘POSIX_ALIASES’ is set, only plain unquoted strings are eligible
for aliasing.  The ‘alias’ builtin does not reject ineligible aliases,
but they are not expanded.

For use with completion, which would remove an initial backslash
followed by a character that isn’t special, it may be more convenient to
quote the word by starting with a single quote, i.e.  ‘'foo’; completion
will automatically add the trailing single quote.

* Menu:

* Alias Difficulties::


File: zsh.info,  Node: Alias Difficulties,  Up: Aliasing

5.8.1 Alias Difficulties
------------------------

Although aliases can be used in ways that bend normal shell syntax, not
every string of non-white-space characters can be used as an alias.

Any set of characters not listed as a word above is not a word, hence no
attempt is made to expand it as an alias, no matter how it is defined
(i.e.  via the builtin or the special parameter ‘aliases’ described in
*note The zsh/parameter Module: 33.).  However, as noted in the case of
‘POSIX_ALIASES’ above, the shell does not attempt to deduce whether the
string corresponds to a word at the time the alias is created.

For example, an expression containing an ‘=’ at the start of a command
line is an assignment and cannot be expanded as an alias; a lone ‘=’ is
not an assignment but can only be set as an alias using the parameter,
as otherwise the ‘=’ is taken part of the syntax of the builtin command.

It is not presently possible to alias the ‘((’ token that introduces
arithmetic expressions, because until a full statement has been parsed,
it cannot be distinguished from two consecutive ‘(’ tokens introducing
nested subshells.  Also, if a separator such as ‘&&’ is aliased, ‘\&&’
turns into the two tokens ‘\&’ and ‘&’, each of which may have been
aliased separately.  Similarly for ‘\<<’, ‘\>|’, etc.

There is a commonly encountered problem with aliases illustrated by the
following code:

      alias echobar='echo bar'; echobar

This prints a message that the command ‘echobar’ could not be found.
This happens because aliases are expanded when the code is read in; the
entire line is read in one go, so that when ‘echobar’ is executed it is
too late to expand the newly defined alias.  This is often a problem in
shell scripts, functions, and code executed with ‘source’ or ‘.’.
Consequently, use of functions rather than aliases is recommended in
non-interactive code.


File: zsh.info,  Node: Quoting,  Prev: Aliasing,  Up: Shell Grammar

5.9 Quoting
===========

A character may be ‘quoted’ (that is, made to stand for itself) by
preceding it with a ‘\’.  ‘\’ followed by a newline is ignored.

A string enclosed between ‘$’’ and >>‘‘<<‘' is processed the same way as
the string arguments of the ``print’ builtin, and the resulting string
is considered to be entirely quoted.  A literal >>‘‘<<‘' character can
be included in the string by using the ``\’’ escape.

All characters enclosed between a pair of single quotes (‘''’) that is
not preceded by a ‘$’ are quoted.  A single quote cannot appear within
single quotes unless the option ‘RC_QUOTES’ is set, in which case a pair
of single quotes are turned into a single quote.  For example,

      print ''''

outputs nothing apart from a newline if ‘RC_QUOTES’ is not set, but one
single quote if it is set.

Inside double quotes (‘""’), parameter and command substitution occur,
and ‘\’ quotes the characters ‘\’, ‘`\’‘’, ‘"’, ‘$’, and the first
character of ‘$histchars’ (default ‘!’).


File: zsh.info,  Node: Redirection,  Next: Command Execution,  Prev: Shell Grammar,  Up: Top

6 Redirection
*************

If a command is followed by ‘&’ and job control is not active, then the
default standard input for the command is the empty file ‘/dev/null’.
Otherwise, the environment for the execution of a command contains the
file descriptors of the invoking shell as modified by input/output
specifications.

The following may appear anywhere in a simple command or may precede or
follow a complex command.  Expansion occurs before WORD or DIGIT is used
except as noted below.  If the result of substitution on WORD produces
more than one filename, redirection occurs for each separate filename in
turn.

‘<’ WORD

     Open file WORD for reading as standard input.  It is an error to
     open a file in this fashion if it does not exist.

‘<>’ WORD

     Open file WORD for reading and writing as standard input.  If the
     file does not exist then it is created.

‘>’ WORD

     Open file WORD for writing as standard output.  If the file does
     not exist then it is created.  If the file exists, and the
     ‘CLOBBER’ option is unset, this causes an error; otherwise, it is
     truncated to zero length.

‘>|’ WORD

‘>!’  WORD

     Same as ‘>’, except that the file is truncated to zero length if it
     exists, regardless of ‘CLOBBER’.

‘>>’ WORD

     Open file WORD for writing in append mode as standard output.  If
     the file does not exist, and the ‘CLOBBER’ and ‘APPEND_CREATE’
     options are both unset, this causes an error; otherwise, the file
     is created.

‘>>|’ WORD

‘>>!’  WORD

     Same as ‘>>’, except that the file is created if it does not exist,
     regardless of ‘CLOBBER’ and ‘APPEND_CREATE’.

‘<<[-’] WORD

     The shell input is read up to a line that is the same as WORD, or
     to an end-of-file.  No parameter expansion, command substitution or
     filename generation is performed on WORD.  The resulting document,
     called a ‘here-document’, becomes the standard input.

     If any character of WORD is quoted with single or double quotes or
     a ‘\’, no interpretation is placed upon the characters of the
     document.  Otherwise, parameter and command substitution occurs,
     ‘\’ followed by a newline is removed, and ‘\’ must be used to quote
     the characters ‘\’, ‘$’, ‘`\’‘’ and the first character of WORD.

     Note that WORD itself does not undergo shell expansion.  Backquotes
     in WORD do not have their usual effect; instead they behave
     similarly to double quotes, except that the backquotes themselves
     are passed through unchanged.  (This information is given for
     completeness and it is not recommended that backquotes be used.)
     Quotes in the form ‘$'’…‘'’ have their standard effect of expanding
     backslashed references to special characters.

     If ‘<<-’ is used, then all leading tabs are stripped from WORD and
     from the document.

‘<<<’ WORD

     Perform shell expansion on WORD and pass the result to standard
     input.  This is known as a ‘here-string’.  Compare the use of WORD
     in here-documents above, where WORD does not undergo shell
     expansion.  The result will have a trailing newline after it.

‘<&’ NUMBER

‘>&’ NUMBER

     The standard input/output is duplicated from file descriptor NUMBER
     (see ‘dup2(2)’).

‘<& -’

‘>& -’

     Close the standard input/output.

‘<& p’

‘>& p’

     The input/output from/to the coprocess is moved to the standard
     input/output.

‘>&’ WORD

‘&>’ WORD

     (Except where ‘>&’ WORD matches one of the above syntaxes; ‘&>’ can
     always be used to avoid this ambiguity.)  Redirects both standard
     output and standard error (file descriptor 2) in the manner of ‘>’
     WORD.  Note that this does ‘not’ have the same effect as ‘>’ WORD
     ‘2>&1’ in the presence of multios (see the section below).

‘>&|’ WORD

‘>&!’  WORD

‘&>|’ WORD

‘&>!’  WORD

     Redirects both standard output and standard error (file descriptor
     2) in the manner of ‘>|’ WORD.

‘>>&’ WORD

‘&>>’ WORD

     Redirects both standard output and standard error (file descriptor
     2) in the manner of ‘>>’ WORD.

‘>>&|’ WORD

‘>>&!’  WORD

‘&>>|’ WORD

‘&>>!’  WORD

     Redirects both standard output and standard error (file descriptor
     2) in the manner of ‘>>|’ WORD.

If one of the above is preceded by a digit, then the file descriptor
referred to is that specified by the digit instead of the default 0 or
1.  The order in which redirections are specified is significant.  The
shell evaluates each redirection in terms of the (‘file descriptor’,
‘file’) association at the time of evaluation.  For example:

     … ‘1>’FNAME ‘2>&1’

first associates file descriptor 1 with file FNAME.  It then associates
file descriptor 2 with the file associated with file descriptor 1 (that
is, FNAME).  If the order of redirections were reversed, file descriptor
2 would be associated with the terminal (assuming file descriptor 1 had
been) and then file descriptor 1 would be associated with file FNAME.

The ‘|&’ command separator described in *note Simple Commands &
Pipelines: 37. is a shorthand for ‘2>&1 |’.

The various forms of process substitution, ‘<(’LIST‘)’, and ‘=(’LIST‘)’
for input and ‘>(’LIST‘)’ for output, are often used together with
redirection.  For example, if WORD in an output redirection is of the
form ‘>(’LIST‘)’ then the output is piped to the command represented by
LIST.  See *note Process Substitution: 38.  Opening file descriptors
using parameters ——————————————————————————– ..  index:: single: file
descriptors, use with parameters; Command

When the shell is parsing arguments to a command, and the shell option
‘IGNORE_BRACES’ is not set, a different form of redirection is allowed:
instead of a digit before the operator there is a valid shell identifier
enclosed in braces.  The shell will open a new file descriptor that is
guaranteed to be at least 10 and set the parameter named by the
identifier to the file descriptor opened.  No whitespace is allowed
between the closing brace and the redirection character.  For example:

     … ‘{myfd}>&1’

This opens a new file descriptor that is a duplicate of file descriptor
1 and sets the parameter ‘myfd’ to the number of the file descriptor,
which will be at least 10.  The new file descriptor can be written to
using the syntax ‘>&$myfd’.  The file descriptor remains open in
subshells and forked external executables.

The syntax ‘{’VARID‘}>&-’, for example ‘{myfd}>&-’, may be used to close
a file descriptor opened in this fashion.  Note that the parameter given
by VARID must previously be set to a file descriptor in this case.

It is an error to open or close a file descriptor in this fashion when
the parameter is readonly.  However, it is not an error to read or write
a file descriptor using ‘<&$’PARAM or ‘>&$’PARAM if PARAM is readonly.

If the option ‘CLOBBER’ is unset, it is an error to open a file
descriptor using a parameter that is already set to an open file
descriptor previously allocated by this mechanism.  Unsetting the
parameter before using it for allocating a file descriptor avoids the
error.

Note that this mechanism merely allocates or closes a file descriptor;
it does not perform any redirections from or to it.  It is usually
convenient to allocate a file descriptor prior to use as an argument to
‘exec’.  The syntax does not in any case work when used around complex
commands such as parenthesised subshells or loops, where the opening
brace is interpreted as part of a command list to be executed in the
current shell.

The following shows a typical sequence of allocation, use, and closing
of a file descriptor:

      integer myfd
      exec {myfd}>~/logs/mylogfile.txt
      print This is a log message. >&$myfd
      exec {myfd}>&-

Note that the expansion of the variable in the expression ‘>&$myfd’
occurs at the point the redirection is opened.  This is after the
expansion of command arguments and after any redirections to the left on
the command line have been processed.

* Menu:

* Multios::
* Redirections with no command::


File: zsh.info,  Node: Multios,  Next: Redirections with no command,  Up: Redirection

6.1 Multios
===========

If the user tries to open a file descriptor for writing more than once,
the shell opens the file descriptor as a pipe to a process that copies
its input to all the specified outputs, similar to ‘tee’, provided the
‘MULTIOS’ option is set, as it is by default.  Thus:

      date >foo >bar

writes the date to two files, named ‘foo’ and ‘bar’.  Note that a pipe
is an implicit redirection; thus

      date >foo | cat

writes the date to the file ‘foo’, and also pipes it to cat.

Note that the shell opens all the files to be used in the multio process
immediately, not at the point they are about to be written.

Note also that redirections are always expanded in order.  This happens
regardless of the setting of the ‘MULTIOS’ option, but with the option
in effect there are additional consequences.  For example, the meaning
of the expression ‘>&1’ will change after a previous redirection:

      date >&1 >output

In the case above, the ‘>&1’ refers to the standard output at the start
of the line; the result is similar to the ‘tee’ command.  However,
consider:

      date >output >&1

As redirections are evaluated in order, when the ‘>&1’ is encountered
the standard output is set to the file ‘output’ and another copy of the
output is therefore sent to that file.  This is unlikely to be what is
intended.

If the ‘MULTIOS’ option is set, the word after a redirection operator is
also subjected to filename generation (globbing).  Thus

      : > *

will truncate all files in the current directory, assuming there’s at
least one.  (Without the ‘MULTIOS’ option, it would create an empty file
called ‘*’.)  Similarly, you can do

      echo exit 0 >> *.sh

If the user tries to open a file descriptor for reading more than once,
the shell opens the file descriptor as a pipe to a process that copies
all the specified inputs to its output in the order specified, provided
the ‘MULTIOS’ option is set.  It should be noted that each file is
opened immediately, not at the point where it is about to be read: this
behaviour differs from ‘cat’, so if strictly standard behaviour is
needed, ‘cat’ should be used instead.

Thus

      sort <foo <fubar

or even

      sort <f{oo,ubar}

is equivalent to ‘cat foo fubar | sort’.

Expansion of the redirection argument occurs at the point the
redirection is opened, at the point described above for the expansion of
the variable in ‘>&$myfd’.

Note that a pipe is an implicit redirection; thus

      cat bar | sort <foo

is equivalent to ‘cat bar foo | sort’ (note the order of the inputs).

If the ‘MULTIOS’ option is ‘un’set, each redirection replaces the
previous redirection for that file descriptor.  However, all files
redirected to are actually opened, so

      echo Hello > bar > baz

when ‘MULTIOS’ is unset will truncate ‘bar’, and write ‘Hello’ into
‘baz’.

There is a problem when an output multio is attached to an external
program.  A simple example shows this:

      cat file >file1 >file2
      cat file1 file2

Here, it is possible that the second ‘cat’ will not display the full
contents of ‘file1’ and ‘file2’ (i.e.  the original contents of ‘file’
repeated twice).

The reason for this is that the multios are spawned after the ‘cat’
process is forked from the parent shell, so the parent shell does not
wait for the multios to finish writing data.  This means the command as
shown can exit before ‘file1’ and ‘file2’ are completely written.  As a
workaround, it is possible to run the ‘cat’ process as part of a job in
the current shell:

      { cat file } >file >file2

Here, the ‘{’…‘}’ job will pause to wait for both files to be written.


File: zsh.info,  Node: Redirections with no command,  Prev: Multios,  Up: Redirection

6.2 Redirections with no command
================================

When a simple command consists of one or more redirection operators and
zero or more parameter assignments, but no command name, zsh can behave
in several ways.

If the parameter ‘NULLCMD’ is not set or the option ‘CSH_NULLCMD’ is
set, an error is caused.  This is the ‘csh’ behavior and ‘CSH_NULLCMD’
is set by default when emulating ‘csh’.

If the option ‘SH_NULLCMD’ is set, the builtin ‘:’ is inserted as a
command with the given redirections.  This is the default when emulating
‘sh’ or ‘ksh’.

Otherwise, if the parameter ‘NULLCMD’ is set, its value will be used as
a command with the given redirections.  If both ‘NULLCMD’ and
‘READNULLCMD’ are set, then the value of the latter will be used instead
of that of the former when the redirection is an input.  The default for
‘NULLCMD’ is ‘cat’ and for ‘READNULLCMD’ is ‘more’.  Thus

      < file

shows the contents of ‘file’ on standard output, with paging if that is
a terminal.  ‘NULLCMD’ and ‘READNULLCMD’ may refer to shell functions.


File: zsh.info,  Node: Command Execution,  Next: Functions,  Prev: Redirection,  Up: Top

7 Command Execution
*******************

If a command name contains no slashes, the shell attempts to locate it.
If there exists a shell function by that name, the function is invoked
as described in ‘Functions’.  If there exists a shell builtin by that
name, the builtin is invoked.

Otherwise, the shell searches each element of ‘$path’ for a directory
containing an executable file by that name.

If execution fails: an error message is printed, and one of the
following values is returned.

127

     The search was unsuccessful.  The error message is ‘command not
     found:’ CMD.

126

     The executable file has insufficient permissions, is a directory or
     special file, or is not a script and is in a format unrecognized by
     the operating system.  The exact conditions and error message are
     operating system-dependent; see ‘execve(2)’.

If execution fails because the file is not in executable format, and the
file is not a directory, it is assumed to be a shell script.  ‘/bin/sh’
is spawned to execute it.  If the program is a file beginning with ‘#!’,
the remainder of the first line specifies an interpreter for the
program.  The shell will execute the specified interpreter on operating
systems that do not handle this executable format in the kernel.

If no external command is found but a function
‘command_not_found_handler’ exists the shell executes this function with
all command line arguments.  The return status of the function becomes
the status of the command.  Note that the handler is executed in a
subshell forked to execute an external command, hence changes to
directories, shell parameters, etc.  have no effect on the main shell.


File: zsh.info,  Node: Functions,  Next: Jobs & Signals,  Prev: Command Execution,  Up: Top

8 Functions
***********

Shell functions are defined with the ‘function’ reserved word or the
special syntax FUNCNAME ‘()’.  Shell functions are read in and stored
internally.  Alias names are resolved when the function is read.
Functions are executed like commands with the arguments passed as
positional parameters.  (See Command Execution.)

Parameters declared by any of the ‘typeset’ family of commands during
the execution of a function become ‘local’ to the function unless the
‘-g’ option is used.  This is the ‘scope’ of the parameter, which
extends dynamically to any other functions called by the declaring
function.  In most cases, local parameters take the place of any other
parameter having the same name that was assigned or declared in an
earlier function scope.  (See *note Local Parameters: 40.)

A named parameter declared with the ‘-n’ option to any of the ‘typeset’
acts as a reference to another parameter, which may be at a different
call level than the declaring function.  When the ‘-u’ option is also
given, the referenced parameter is always found at a call level above
the function where the reference is declared, otherwise the reference
scope is dynamic.  For this reason, it is good practice to declare a
named reference as soon as the referent parameter is in scope, and as
early as possible in the function if the reference is to a parameter in
a calling scope.

A typical use of named references is to pass the name of the referent as
a positional parameter.  In this case it is good practice to use the
‘-u’ option to reference the calling scope.  For example,

      pop() {
        local -nu ref=$1
        local last=$ref[$#ref]
        ref[$#ref]=()
        print -r -- $last
      }
      array=( a list of five values )
      pop array

prints the word ‘values’ and shortens ‘$array’ to ‘( a list of five )’.
With ‘-nu’, ‘ref’ becomes a reference to ‘array’ in the caller.  There
are no local parameters in ‘pop’ at the time ‘ref=$1’ is assigned, so in
this example ‘-u’ could have been omitted, but it makes the intention
clear.

Functions execute in the same process as the caller and share all files
and present working directory with the caller.  A trap on ‘EXIT’ set
inside a function is executed after the function completes in the
environment of the caller.

The ‘return’ builtin is used to return from function calls.

Function identifiers can be listed with the ‘functions’ builtin.  ..
index:: single: unfunction, use of; Function

Functions can be undefined with the ‘unfunction’ builtin.

* Menu:

* Autoloading Functions::
* Anonymous Functions::
* Special Functions::


File: zsh.info,  Node: Autoloading Functions,  Next: Anonymous Functions,  Up: Functions

8.1 Autoloading Functions
=========================

A function can be marked as ‘undefined’ using the ‘autoload’ builtin (or
‘functions -u’ or ‘typeset -fu’).  Such a function has no body.  When
the function is first executed, the shell searches for its definition
using the elements of the ‘fpath’ variable.  Thus to define functions
for autoloading, a typical sequence is:

      fpath=(~/myfuncs $fpath)
      autoload myfunc1 myfunc2 ...

The usual alias expansion during reading will be suppressed if the
‘autoload’ builtin or its equivalent is given the option ‘-U’.  This is
recommended for the use of functions supplied with the zsh distribution.
..  index:: single: zcompile, use of; Function

Note that for functions precompiled with the ‘zcompile’ builtin command
the flag ‘-U’ must be provided when the ‘.zwc’ file is created, as the
corresponding information is compiled into the latter.

For each ELEMENT in ‘fpath’, the shell looks for three possible files,
the newest of which is used to load the definition for the function:

ELEMENT‘.zwc’

     A file created with the ‘zcompile’ builtin command, which is
     expected to contain the definitions for all functions in the
     directory named ELEMENT.  The file is treated in the same manner as
     a directory containing files for functions and is searched for the
     definition of the function.  If the definition is not found, the
     search for a definition proceeds with the other two possibilities
     described below.

     If ELEMENT already includes a ‘.zwc’ extension (i.e.  the extension
     was explicitly given by the user), ELEMENT is searched for the
     definition of the function without comparing its age to that of
     other files; in fact, there does not need to be any directory named
     ELEMENT without the suffix.  Thus including an element such as
     ‘/usr/local/funcs.zwc’ in ‘fpath’ will speed up the search for
     functions, with the disadvantage that functions included must be
     explicitly recompiled by hand before the shell notices any changes.

ELEMENT‘/’FUNCTION‘.zwc’

     A file created with ‘zcompile’, which is expected to contain the
     definition for FUNCTION.  It may include other function definitions
     as well, but those are neither loaded nor executed; a file found in
     this way is searched ‘only’ for the definition of FUNCTION.

ELEMENT‘/’FUNCTION

     A file of zsh command text, taken to be the definition for
     FUNCTION.

In summary, the order of searching is, first, in the ‘parents of’
directories in ‘fpath’ for the newer of either a compiled directory or a
directory in ‘fpath’; second, if more than one of these contains a
definition for the function that is sought, the leftmost in the ‘fpath’
is chosen; and third, within a directory, the newer of either a compiled
function or an ordinary function definition is used.

If the ‘KSH_AUTOLOAD’ option is set, or the file contains only a simple
definition of the function, the file’s contents will be executed.  This
will normally define the function in question, but may also perform
initialization, which is executed in the context of the function
execution, and may therefore define local parameters.  It is an error if
the function is not defined by loading the file.

Otherwise, the function body (with no surrounding FUNCNAME‘() {’…‘‘}‘‘)
is taken to be the complete contents of the file.  This form allows the
file to be used directly as an executable shell script.  If processing
of the file results in the function being re-defined, the function
itself is not re-executed.  To force the shell to perform initialization
and then call the function defined, the file should contain
initialization code (which will be executed then discarded) in addition
to a complete function definition (which will be retained for subsequent
calls to the function), and a call to the shell function, including any
arguments, at the end.

For example, suppose the autoload file ‘func’ contains

      func() { print This is func; }
      print func is initialized

then ‘func; func’ with ‘KSH_AUTOLOAD’ set will produce both messages on
the first call, but only the message ‘This is func’ on the second and
subsequent calls.  Without ‘KSH_AUTOLOAD’ set, it will produce the
initialization message on the first call, and the other message on the
second and subsequent calls.

It is also possible to create a function that is not marked as
autoloaded, but which loads its own definition by searching ‘fpath’, by
using ‘autoload -X’ within a shell function.  For example, the following
are equivalent:

      myfunc() {
        autoload -X
      }
      myfunc args...

and

      unfunction myfunc   # if myfunc was defined
      autoload myfunc
      myfunc args...

In fact, the ‘functions’ command outputs ‘builtin autoload -X’ as the
body of an autoloaded function.  This is done so that

      eval "$(functions)"

produces a reasonable result.  A true autoloaded function can be
identified by the presence of the comment ‘# undefined’ in the body,
because all comments are discarded from defined functions.

To load the definition of an autoloaded function ‘myfunc’ without
executing ‘myfunc’, use:

      autoload +X myfunc


File: zsh.info,  Node: Anonymous Functions,  Next: Special Functions,  Prev: Autoloading Functions,  Up: Functions

8.2 Anonymous Functions
=======================

If no name is given for a function, it is ‘anonymous’ and is handled
specially.  Either form of function definition may be used: a ‘()’ with
no preceding name, or a ‘function’ with an immediately following open
brace.  The function is executed immediately at the point of definition
and is not stored for future use.  The function name is set to ‘(anon)’.

Arguments to the function may be specified as words following the
closing brace defining the function, hence if there are none no
arguments (other than ‘$0’) are set.  This is a difference from the way
other functions are parsed: normal function definitions may be followed
by certain keywords such as ‘else’ or ‘fi’, which will be treated as
arguments to anonymous functions, so that a newline or semicolon is
needed to force keyword interpretation.

Note also that the argument list of any enclosing script or function is
hidden (as would be the case for any other function called at this
point).

Redirections may be applied to the anonymous function in the same manner
as to a current-shell structure enclosed in braces.  The main use of
anonymous functions is to provide a scope for local variables.  This is
particularly convenient in start-up files as these do not provide their
own local variable scope.

For example,

      variable=outside
      function {
        local variable=inside
        print "I am $variable with arguments $*"
      } this and that
      print "I am $variable"

outputs the following:

      I am inside with arguments this and that
      I am outside

Note that function definitions with arguments that expand to nothing,
for example ‘name=; function $name {’ … ‘}’, are not treated as
anonymous functions.  Instead, they are treated as normal function
definitions where the definition is silently discarded.


File: zsh.info,  Node: Special Functions,  Prev: Anonymous Functions,  Up: Functions

8.3 Special Functions
=====================

Certain functions, if defined, have special meaning to the shell.

* Menu:

* Hook Functions::
* Trap Functions::


File: zsh.info,  Node: Hook Functions,  Next: Trap Functions,  Up: Special Functions

8.3.1 Hook Functions
--------------------

For the functions below, it is possible to define an array that has the
same name as the function with ‘_functions’ appended.  Any element in
such an array is taken as the name of a function to execute; it is
executed in the same context and with the same arguments and same
initial value of ‘$?’ as the basic function.  For example, if
‘$chpwd_functions’ is an array containing the values ‘mychpwd’,
‘chpwd_save_dirstack’, then the shell attempts to execute the functions
‘chpwd’, ‘mychpwd’ and ‘chpwd_save_dirstack’, in that order.  Any
function that does not exist is silently ignored.  A function found by
this mechanism is referred to elsewhere as a ‘hook function’.  An error
in any function causes subsequent functions not to be run.  Note further
that an error in a ‘precmd’ hook causes an immediately following
‘periodic’ function not to run (though it may run at the next
opportunity).

‘chpwd’

     Executed whenever the current working directory is changed.

‘periodic’

     If the parameter ‘PERIOD’ is set, this function is executed every
     ‘$PERIOD’ seconds, just before a prompt.  Note that if multiple
     functions are defined using the array ‘periodic_functions’ only one
     period is applied to the complete set of functions, and the
     scheduled time is not reset if the list of functions is altered.
     Hence the set of functions is always called together.

‘precmd’

     Executed before each prompt.  Note that precommand functions are
     not re-executed simply because the command line is redrawn, as
     happens, for example, when a notification about an exiting job is
     displayed.

‘preexec’

     Executed just after a command has been read and is about to be
     executed.  If the history mechanism is active (regardless of
     whether the line was discarded from the history buffer), the string
     that the user typed is passed as the first argument, otherwise it
     is an empty string.  The actual command that will be executed
     (including expanded aliases) is passed in two different forms: the
     second argument is a single-line, size-limited version of the
     command (with things like function bodies elided); the third
     argument contains the full text that is being executed.

‘zshaddhistory’

     Executed when a history line has been read interactively, but
     before it is executed.  The sole argument is the complete history
     line (so that any terminating newline will still be present).

     If any of the hook functions returns status 1 (or any non-zero
     value other than 2, though this is not guaranteed for future
     versions of the shell) the history line will not be saved, although
     it lingers in the history until the next line is executed, allowing
     you to reuse or edit it immediately.

     If any of the hook functions returns status 2 the history line will
     be saved on the internal history list, but not written to the
     history file.  In case of a conflict, the first non-zero status
     value is taken.

     A hook function may call ‘fc -p’ … to switch the history context so
     that the history is saved in a different file from that in the
     global ‘HISTFILE’ parameter.  This is handled specially: the
     history context is automatically restored after the processing of
     the history line is finished.

     The following example function works with one of the options
     ‘INC_APPEND_HISTORY’ or ‘SHARE_HISTORY’ set, in order that the line
     is written out immediately after the history entry is added.  It
     first adds the history line to the normal history with the newline
     stripped, which is usually the correct behaviour.  Then it switches
     the history context so that the line will be written to a history
     file in the current directory.

           zshaddhistory() {
             print -sr -- ${1%%$'\n'}
             fc -p .zsh_local_history
           }

‘zshexit’

     Executed at the point where the main shell is about to exit
     normally.  This is not called by exiting subshells, nor when the
     ‘exec’ precommand modifier is used before an external command.
     Also, unlike ‘TRAPEXIT’, it is not called when functions exit.


File: zsh.info,  Node: Trap Functions,  Prev: Hook Functions,  Up: Special Functions

8.3.2 Trap Functions
--------------------

The functions below are treated specially but do not have corresponding
hook arrays.

‘TRAP’NAL

     If defined and non-null, this function will be executed whenever
     the shell catches a signal ‘SIG’NAL, where NAL is a signal name as
     specified for the ‘kill’ builtin.  The signal number will be passed
     as the first parameter to the function.

     If a function of this form is defined and null, the shell and
     processes spawned by it will ignore ‘SIG’NAL.

     The return status from the function is handled specially.  If it is
     zero, the signal is assumed to have been handled, and execution
     continues normally.  Otherwise, the shell will behave as
     interrupted except that the return status of the trap is retained.

     Programs terminated by uncaught signals typically return the status
     128 plus the signal number.  Hence the following causes the handler
     for ‘SIGINT’ to print a message, then mimic the usual effect of the
     signal.

           TRAPINT() {
             print "Caught SIGINT, aborting."
             return $(( 128 + $1 ))
           }

     The functions ‘TRAPZERR’, ‘TRAPDEBUG’ and ‘TRAPEXIT’ are never
     executed inside other traps.

‘TRAPDEBUG’

     If the option ‘DEBUG_BEFORE_CMD’ is set (as it is by default),
     executed before each command; otherwise executed after each
     command.  See the description of the ‘trap’ builtin in
     ‘zshbuiltins’ for details of additional features provided in debug
     traps.

‘TRAPEXIT’

     Executed when the shell exits, or when the current function exits
     if defined inside a function.  The value of ‘$?’ at the start of
     execution is the exit status of the shell or the return status of
     the function exiting.

‘TRAPZERR’

     Executed whenever a command has a non-zero exit status.  However,
     the function is not executed if the command occurred in a sublist
     followed by ‘&&’ or ‘||’; only the final command in a sublist of
     this type causes the trap to be executed.  The function ‘TRAPERR’
     acts the same as ‘TRAPZERR’ on systems where there is no ‘SIGERR’
     (this is the usual case).

The functions beginning ‘TRAP’ may alternatively be defined with the
‘trap’ builtin: this may be preferable for some uses.  Setting a trap
with one form removes any trap of the other form for the same signal;
removing a trap in either form removes all traps for the same signal.
The forms

      TRAPNAL() {
       # code
      }

(‘function traps’) and

      trap '
       # code
      ' NAL

(‘list traps’) are equivalent in most ways, the exceptions being the
following:

        * Function traps have all the properties of normal functions,

     appearing in the list of functions and being called with their own
     function context rather than the context where the trap was
     triggered.  * The return status from function traps is special,
     whereas a return from a list trap causes the surrounding context to
     return with the given status.  * Function traps are not reset
     within subshells, in accordance with zsh behaviour; list traps are
     reset, in accordance with POSIX behaviour.


File: zsh.info,  Node: Jobs & Signals,  Next: Arithmetic Evaluation,  Prev: Functions,  Up: Top

9 Jobs & Signals
****************

* Menu:

* Jobs::
* Signals::


File: zsh.info,  Node: Jobs,  Next: Signals,  Up: Jobs & Signals

9.1 Jobs
========

If the ‘MONITOR’ option is set, an interactive shell associates a ‘job’
with each pipeline.  It keeps a table of current jobs, printed by the
‘jobs’ command, and assigns them small integer numbers.  When a job is
started asynchronously with ‘&’, the shell prints a line to standard
error which looks like:

      [1] 1234

indicating that the job which was started asynchronously was job number
1 and had one (top-level) process, whose process ID was 1234.

If a job is started with ‘&|’ or ‘&!’, then that job is immediately
disowned.  After startup, it does not have a place in the job table, and
is not subject to the job control features described here.

If you are running a job and wish to do something else you may hit the
key ^Z (control-Z) which sends a ‘TSTP’ signal to the current job: this
key may be redefined by the ‘susp’ option of the external ‘stty’
command.  ..  index:: single: jobs, suspending; Command

The shell will then normally indicate that the job has been ‘suspended’,
and print another prompt.  You can then manipulate the state of this
job, ..  index:: single: bg, use of; Function

putting it in the background with the ‘bg’ command, or run some other
commands and then eventually bring the job back into the foreground with
..  index:: single: fg, use of; Function

the foreground command ‘fg’.  A ^Z takes effect immediately and is like
an interrupt in that pending output and unread input are discarded when
it is typed.

A job being run in the background will suspend if it tries to read from
the terminal.

Note that if the job running in the foreground is a shell function, then
suspending it will have the effect of causing the shell to fork.  This
is necessary to separate the function’s state from that of the parent
shell performing the job control, so that the latter can return to the
command line prompt.  As a result, even if ‘fg’ is used to continue the
job the function will no longer be part of the parent shell, and any
variables set by the function will not be visible in the parent shell.
Thus the behaviour is different from the case where the function was
never suspended.  Zsh is different from many other shells in this
regard.

One additional side effect is that use of ‘disown’ with a job created by
suspending shell code in this fashion is delayed: the job can only be
disowned once any process started from the parent shell has terminated.
At that point, the disowned job disappears silently from the job list.

The same behaviour is found when the shell is executing code as the
right hand side of a pipeline or any complex shell construct such as
‘if’, ‘for’, etc., in order that the entire block of code can be managed
as a single job.  ..  index:: single: background jobs, I/O; Command

Background jobs are normally allowed to produce output, but this can be
disabled by giving the command ‘stty tostop’.  If you set this tty
option, then background jobs will suspend when they try to produce
output like they do when they try to read input.

When a command is suspended and continued later with the ‘fg’ or ‘wait’
builtins, zsh restores tty modes that were in effect when it was
suspended.  This (intentionally) does not apply if the command is
continued via ‘kill -CONT’, nor when it is continued with ‘bg’.

There are several ways to refer to jobs in the shell.  A job can be
referred to by the process ID of any process of the job or by one of the
following:

‘%’NUMBER

     The job with the given number.

‘%’STRING

     The last job whose command line begins with STRING.

‘%?’STRING

     The last job whose command line contains STRING.

‘%%’

     Current job.

‘%+’

     Equivalent to ‘%%’.

‘%-’

     Previous job.

The shell learns immediately whenever a process changes state.  ..
index:: single: NOTIFY, use of; Program

It normally informs you whenever a job becomes blocked so that no
further progress is possible.  If the ‘NOTIFY’ option is not set, it
waits until just before it prints a prompt before it informs you.  All
such notifications are sent directly to the terminal, not to the
standard output or standard error.

When the monitor mode is on, each background job that completes triggers
any trap set for ‘CHLD’.

When you try to leave the shell while jobs are running or suspended, you
will be warned that ‘You have suspended (running) jobs’.  You may use
the ‘jobs’ command to see what they are.  If you do this or immediately
try to exit again, the shell will not warn you a second time; the
suspended jobs will be terminated, and the running jobs will be sent a
‘SIGHUP’ signal, if the ‘HUP’ option is set.  ..  index:: single: HUP,
use of; Program

To avoid having the shell terminate the running jobs, either use the
‘nohup(1)’ command or the ‘disown’ builtin.


File: zsh.info,  Node: Signals,  Prev: Jobs,  Up: Jobs & Signals

9.2 Signals
===========

The ‘INT’ and ‘QUIT’ signals for an invoked command are ignored if the
command is followed by ‘&’ and the ‘MONITOR’ option is not active.  The
shell itself always ignores the ‘QUIT’ signal.  Otherwise, signals have
the values inherited by the shell from its parent (but see the ‘TRAP’NAL
special functions in Functions).

Certain jobs are run asynchronously by the shell other than those
explicitly put into the background; even in cases where the shell would
usually wait for such jobs, an explicit ‘exit’ command or exit due to
the option ‘ERR_EXIT’ will cause the shell to exit without waiting.
Examples of such asynchronous jobs are process substitution, see *note
Process Substitution: 38, and the handler processes for multios, see
*note Multios: 4d.


File: zsh.info,  Node: Arithmetic Evaluation,  Next: Conditional Expressions,  Prev: Jobs & Signals,  Up: Top

10 Arithmetic Evaluation
************************

The shell can perform integer and floating point arithmetic, either
using the builtin ‘let’, or via a substitution of the form ‘$((’…‘))’.
For integers, the shell is usually compiled to use 8-byte precision
where this is available, otherwise precision is 4 bytes.  This can be
tested, for example, by giving the command ‘print - $(( 12345678901 ))’;
if the number appears unchanged, the precision is at least 8 bytes.
Floating point arithmetic always uses the ‘double’ type with whatever
corresponding precision is provided by the compiler and the library.

The ‘let’ builtin command takes arithmetic expressions as arguments;
each is evaluated separately.  Since many of the arithmetic operators,
as well as spaces, require quoting, an alternative form is provided: for
any command which begins with a ‘((’, all the characters until a
matching ‘))’ are treated as a double-quoted expression and arithmetic
expansion performed as for an argument of ‘let’.  More precisely,
‘((’…‘))’ is equivalent to ‘let "’…‘"’.  The return status is 0 if the
arithmetic value of the expression is non-zero, 1 if it is zero, and 2
if an error occurred.  Floating point exceptions (division by zero,
overflow, etc.)  are ignored and not considered as errors.

For example, the following statement

      (( val = 2 + 1 ))

is equivalent to

      let "val = 2 + 1"

both assigning the value 3 to the shell variable ‘val’ and returning a
zero status.

Integers can be in bases other than 10.  A leading ‘0x’ or ‘0X’ denotes
hexadecimal and a leading ‘0b’ or ‘0B’ binary.  Integers may also be of
the form BASE‘#’N, where BASE is a decimal number between two and
thirty-six representing the arithmetic base and N is a number in that
base (for example, ‘16#ff’ is 255 in hexadecimal).  The BASE‘#’ may also
be omitted, in which case base 10 is used.  For backwards compatibility
the form ‘[’BASE‘]’N is also accepted.

An integer expression or a base given in the form BASE‘#’N may contain
underscores (‘_’) after the leading digit for visual guidance; these are
ignored in computation.  Examples are ‘1_000_000’ or ‘0xffff_ffff’ which
are equivalent to ‘1000000’ and ‘0xffffffff’ respectively.

It is also possible to specify a base to be used for output in the form
‘[#’BASE‘]’, for example ‘[#16]’.  This is used when outputting
arithmetical substitutions or when assigning to scalar parameters, but
an explicitly defined integer or floating point parameter will not be
affected.  If an integer variable is implicitly defined by an arithmetic
expression, any base specified in this way will be set as the variable’s
output arithmetic base as if the option ‘-i’ BASE to the ‘typeset’
builtin had been used.  The expression has no precedence and if it
occurs more than once in a mathematical expression, the last encountered
is used.  For clarity it is recommended that it appear at the beginning
of an expression.  As an example:

      typeset -i 16 y
      print $(( [#8] x = 32, y = 32 ))
      print $x $y

outputs first ‘8#40’, the rightmost value in the given output base, and
then ‘8#40 16#20’, because ‘y’ has been explicitly declared to have
output base 16, while ‘x’ (assuming it does not already exist) is
implicitly typed by the arithmetic evaluation, where it acquires the
output base 8.

The BASE may be replaced or followed by an underscore, which may itself
be followed by a positive integer (if it is missing the value 3 is
used).  This indicates that underscores should be inserted into the
output string, grouping the number for visual clarity.  The following
integer specifies the number of digits to group together.  For example:

      setopt cbases
      print $(( [#16_4] 65536 ** 2 ))

outputs ‘0x1_0000_0000’.

The feature can be used with floating point numbers, in which case the
base must be omitted; grouping is away from the decimal point.  For
example,

      zmodload zsh/mathfunc
      print $(( [#_] sqrt(1e7) ))

outputs ‘3_162.277_660_168_379_5’ (the number of decimal places shown
may vary).

If the ‘C_BASES’ option is set, hexadecimal numbers are output in the
standard C format, for example ‘0xFF’ instead of the usual ‘16#FF’.  If
the option ‘OCTAL_ZEROES’ is also set (it is not by default), octal
numbers will be treated similarly and hence appear as ‘077’ instead of
‘8#77’.  This option has no effect on the output of bases other than
hexadecimal and octal, and these formats are always understood on input.

When an output base is specified using the ‘[#’BASE‘]’ syntax, an
appropriate base prefix will be output if necessary, so that the value
output is valid syntax for input.  If the ‘#’ is doubled, for example
‘[##16]’, then no base prefix is output.

Floating point constants are recognized by the presence of a decimal
point or an exponent.  The decimal point may be the first character of
the constant, but the exponent character ‘e’ or ‘E’ may not, as it will
be taken for a parameter name.  All numeric parts (before and after the
decimal point and in the exponent) may contain underscores after the
leading digit for visual guidance; these are ignored in computation.

The special floating point values NaN (not a number) and infinity are
fully supported in floating point arithmetic.  They may be produced by
certain operations, such as division by zero, or referenced explicitly
in arithmetic constructs and float assignments using the
case-insensitive constants ‘NaN’ and ‘Inf’.  Expansion syntax must be
used to reference a parameter with one of these names in these contexts:

      % nan=123 INF=456
      % print $(( nan )) $(( INF ))
      NaN Inf
      % print $(( $nan )) $(( $INF ))
      123 456
      % typeset -F f=nan && typeset -p f
      typeset -F f=NaN
      % typeset -F f=$nan && typeset -p f
      typeset -F f=123.0000000000

To check whether a value is NaN, either use the ‘isnan’ function
provided by the ‘zsh/mathfunc’ module or compare it to the string ‘NaN’:

      % zmodload zsh/mathfunc
      % (( isnan(0.0 / 0) )) && print is nan
      is nan
      % typeset -F f=nan && [[ $f == NaN ]] && print is nan
      is nan

An arithmetic expression uses nearly the same syntax and associativity
of expressions as in C.

In the native mode of operation, the following operators are supported
(listed in decreasing order of precedence):

‘+ - ! ~ ++ --’

     unary plus/minus, logical NOT, complement, {pre,post}{in,de}crement

‘<< >>’

     bitwise shift left, right

‘&’

     bitwise AND

‘^’

     bitwise XOR

‘|’

     bitwise OR

‘**’

     exponentiation

‘* / %’

     multiplication, division, modulus (remainder)

‘+ -’

     addition, subtraction

‘< > <= >=’

     comparison

‘== !=’

     equality and inequality

‘&&’

     logical AND

‘|| ^^’

     logical OR, XOR

‘? :’

     ternary operator

‘= += -= *= /= %= &= ^= |= <<= >>= &&= ||= ^^= **=’

     assignment

‘,’

     comma operator

The operators ‘&&’, ‘||’, ‘&&=’, and ‘||=’ are short-circuiting, and
only one of the latter two expressions in a ternary operator is
evaluated.  Note the precedence of the bitwise AND, OR, and XOR
operators.

With the option ‘C_PRECEDENCES’ the precedences (but no other
properties) of the operators are altered to be the same as those in most
other languages that support the relevant operators:

‘+ - ! ~ ++ --’

     unary plus/minus, logical NOT, complement, {pre,post}{in,de}crement

‘**’

     exponentiation

‘* / %’

     multiplication, division, modulus (remainder)

‘+ -’

     addition, subtraction

‘<< >>’

     bitwise shift left, right

‘< > <= >=’

     comparison

‘== !=’

     equality and inequality

‘&’

     bitwise AND

‘^’

     bitwise XOR

‘|’

     bitwise OR

‘&&’

     logical AND

‘^^’

     logical XOR

‘||’

     logical OR

‘? :’

     ternary operator

‘= += -= *= /= %= &= ^= |= <<= >>= &&= ||= ^^= **=’

     assignment

‘,’

     comma operator

Note the precedence of exponentiation in both cases is below that of
unary operators, hence ‘-3**2’ evaluates as ‘9’, not ‘-9’.  Use
parentheses where necessary: ‘-(3**2)’.  This is for compatibility with
other shells.

Mathematical functions can be called with the syntax FUNC‘(’ARGS‘)’,
where the function decides if the ARGS is used as a string or a
comma-separated list of arithmetic expressions.  The shell currently
defines no mathematical functions by default, but the module
‘zsh/mathfunc’ may be loaded with the ‘zmodload’ builtin to provide
standard floating point mathematical functions.

An expression of the form ‘##’X where X is any character sequence such
as ‘a’, ‘^A’, or ‘\M-\C-x’ gives the value of this character and an
expression of the form ‘#’NAME gives the value of the first character of
the contents of the parameter NAME.  Character values are according to
the character set used in the current locale; for multibyte character
handling the option ‘MULTIBYTE’ must be set.  Note that this form is
different from ‘$#’NAME, a standard parameter substitution which gives
the length of the parameter NAME.  ‘#\’ is accepted instead of ‘##’, but
its use is deprecated.

Named parameters and subscripted arrays can be referenced by name within
an arithmetic expression without using the parameter expansion syntax.
For example,

      ((val2 = val1 * 2))

assigns twice the value of ‘$val1’ to the parameter named ‘val2’.  If
the expansion of ‘$val1’ is text rather than a number, then when ‘val1’
is referenced that text is itself evaluated as a math expression as if
surrounded by parentheses ‘($val1)’.  Expansion continues until there
are no more parameter references, a number has resulted, or an
expression error occurs.

An internal integer representation of a named parameter can be specified
with the ‘integer’ builtin.  ..  index:: single: parameters, integer;
Command

Arithmetic evaluation is performed on the value of each assignment to a
named parameter declared integer in this manner.  Assigning a floating
point number to an integer results in rounding towards zero.

Likewise, floating point numbers can be declared with the ‘float’
builtin; there are two types, differing only in their output format, as
described for the ‘typeset’ builtin.  The output format can be bypassed
by using arithmetic substitution instead of the parameter substitution,
i.e.  ‘${’FLOAT‘}’ uses the defined format, but ‘$((’FLOAT‘))’ uses a
generic floating point format.

Promotion of integer to floating point values is performed where
necessary.  In addition, if any operator which requires an integer (‘&’,
‘|’, ‘^’, ‘<<’, ‘>>’ and their equivalents with assignment) is given a
floating point argument, it will be silently rounded towards zero except
for ‘~’ which rounds down.

Users should beware that, in common with many other programming
languages but not software designed for calculation, the evaluation of
an expression in zsh is taken a term at a time and promotion of integers
to floating point does not occur in terms only containing integers.  A
typical result of this is that a division such as ‘6/8’ is truncated, in
this being rounded towards 0.  The ‘FORCE_FLOAT’ shell option can be
used in scripts or functions where floating point evaluation is required
throughout.

Scalar variables can hold integer or floating point values at different
times; there is no memory of the numeric type in this case.

If a variable is first assigned in a numeric context without previously
being declared, it will be implicitly typed as ‘integer’ or ‘float’ and
retain that type either until the type is explicitly changed or until
the end of the scope.  This can have unforeseen consequences.  For
example, in the loop

      for (( f = 0; f < 1; f += 0.1 )); do
      # use $f
      done

if ‘f’ has not already been declared, the first assignment will cause it
to be created as an integer, and consequently the operation ‘f += 0.1’
will always cause the result to be truncated to zero, so that the loop
will fail.  A simple fix would be to turn the initialization into ‘f =
0.0’.  It is therefore best to declare numeric variables with explicit
types.


File: zsh.info,  Node: Conditional Expressions,  Next: Prompt Expansion,  Prev: Arithmetic Evaluation,  Up: Top

11 Conditional Expressions
**************************

A ‘conditional expression’ is used with the ‘[[’ compound command to
test attributes of files and to compare strings.  Each expression can be
constructed from one or more of the following unary or binary
expressions:

‘-a’ FILE

     true if FILE exists.

‘-b’ FILE

     true if FILE exists and is a block special file.

‘-c’ FILE

     true if FILE exists and is a character special file.

‘-d’ FILE

     true if FILE exists and is a directory.

‘-e’ FILE

     true if FILE exists.

‘-f’ FILE

     true if FILE exists and is a regular file.

‘-g’ FILE

     true if FILE exists and has its setgid bit set.

‘-h’ FILE

     true if FILE exists and is a symbolic link.

‘-k’ FILE

     true if FILE exists and has its sticky bit set.

‘-n’ STRING

     true if length of STRING is non-zero.

‘-o’ OPTION

     true if option named OPTION is on.  OPTION may be a single
     character, in which case it is a single letter option name.  (See
     *note Specifying Options: 52.)

     When no option named OPTION exists, and the ‘POSIX_BUILTINS’ option
     hasn’t been set, return 3 with a warning.  If that option is set,
     return 1 with no warning.

‘-p’ FILE

     true if FILE exists and is a FIFO special file (named pipe).

‘-r’ FILE

     true if FILE exists and is readable by current process.

‘-s’ FILE

     true if FILE exists and has size greater than zero.

‘-t’ FD

     true if file descriptor number FD is open and associated with a
     terminal device.  (note: FD is not optional)

‘-u’ FILE

     true if FILE exists and has its setuid bit set.

‘-v’ VARNAME

     true if shell variable VARNAME is set.

‘-w’ FILE

     true if FILE exists and is writable by current process.

‘-x’ FILE

     true if FILE exists and is executable by current process.  If FILE
     exists and is a directory, then the current process has permission
     to search in the directory.

‘-z’ STRING

     true if length of STRING is zero.

‘-L’ FILE

     true if FILE exists and is a symbolic link.

‘-O’ FILE

     true if FILE exists and is owned by the effective user ID of this
     process.

‘-G’ FILE

     true if FILE exists and its group matches the effective group ID of
     this process.

‘-S’ FILE

     true if FILE exists and is a socket.

‘-N’ FILE

     true if FILE exists and its access time is not newer than its
     modification time.

FILE1 ‘-nt’ FILE2

     true if FILE1 exists and is newer than FILE2.

FILE1 ‘-ot’ FILE2

     true if FILE1 exists and is older than FILE2.

FILE1 ‘-ef’ FILE2

     true if FILE1 and FILE2 exist and refer to the same file.

STRING ‘=’ PATTERN

STRING ‘==’ PATTERN

     true if STRING matches PATTERN.  The two forms are exactly
     equivalent.  The ‘=’ form is the traditional shell syntax (and
     hence the only one generally used with the ‘test’ and ‘[’
     builtins); the ‘==’ form provides compatibility with other sorts of
     computer language.

STRING ‘!=’ PATTERN

     true if STRING does not match PATTERN.

STRING ‘=~’ REGEXP

     true if STRING matches the regular expression REGEXP.  If the
     option ‘RE_MATCH_PCRE’ is set REGEXP is tested as a PCRE regular
     expression using the ‘zsh/pcre’ module, else it is tested as a
     POSIX extended regular expression using the ‘zsh/regex’ module.
     Upon successful match, some variables will be updated; no variables
     are changed if the matching fails.

     If the option ‘BASH_REMATCH’ is not set the scalar parameter
     ‘MATCH’ is set to the substring that matched the pattern and the
     integer parameters ‘MBEGIN’ and ‘MEND’ to the index of the start
     and end, respectively, of the match in STRING, such that if STRING
     is contained in variable ‘var’ the expression
     ‘${var[$MBEGIN,$MEND]}’ is identical to ‘$MATCH’.  The setting of
     the option ‘KSH_ARRAYS’ is respected.  Likewise, the array ‘match’
     is set to the substrings that matched parenthesised subexpressions
     and the arrays ‘mbegin’ and ‘mend’ to the indices of the start and
     end positions, respectively, of the substrings within STRING.  The
     arrays are not set if there were no parenthesised subexpressions.
     For example, if the string ‘a short string’ is matched against the
     regular expression ‘s(...)t’, then (assuming the option
     ‘KSH_ARRAYS’ is not set) ‘MATCH’, ‘MBEGIN’ and ‘MEND’ are ‘short’,
     ‘3’ and ‘7’, respectively, while ‘match’, ‘mbegin’ and ‘mend’ are
     single entry arrays containing the strings ‘hor’, ‘4’ and ‘6’,
     respectively.

     If the option ‘BASH_REMATCH’ is set the array ‘BASH_REMATCH’ is set
     to the substring that matched the pattern followed by the
     substrings that matched parenthesised subexpressions within the
     pattern.

STRING1 ‘<’ STRING2

     true if STRING1 comes before STRING2 based on ASCII value of their
     characters.

STRING1 ‘>’ STRING2

     true if STRING1 comes after STRING2 based on ASCII value of their
     characters.

EXP1 ‘-eq’ EXP2

     true if EXP1 is numerically equal to EXP2.  Note that for purely
     numeric comparisons use of the ‘((’…‘))’ builtin described in
     ‘Arithmetic Evaluation’ is more convenient than conditional
     expressions.

EXP1 ‘-ne’ EXP2

     true if EXP1 is numerically not equal to EXP2.

EXP1 ‘-lt’ EXP2

     true if EXP1 is numerically less than EXP2.

EXP1 ‘-gt’ EXP2

     true if EXP1 is numerically greater than EXP2.

EXP1 ‘-le’ EXP2

     true if EXP1 is numerically less than or equal to EXP2.

EXP1 ‘-ge’ EXP2

     true if EXP1 is numerically greater than or equal to EXP2.

‘(’ EXP ‘)’

     true if EXP is true.

‘!’  EXP

     true if EXP is false.

EXP1 ‘&&’ EXP2

     true if EXP1 and EXP2 are both true.

EXP1 ‘||’ EXP2

     true if either EXP1 or EXP2 is true.

For compatibility, if there is a single argument that is not
syntactically significant, typically a variable, the condition is
treated as a test for whether the expression expands as a string of
non-zero length.  In other words, ‘[[ $var ]]’ is the same as ‘[[ -n
$var ]]’.  It is recommended that the second, explicit, form be used
where possible.

Normal shell expansion is performed on the FILE, STRING and PATTERN
arguments, but the result of each expansion is constrained to be a
single word, similar to the effect of double quotes.

Filename generation is not performed on any form of argument to
conditions.  However, it can be forced in any case where normal shell
expansion is valid and when the option ‘EXTENDED_GLOB’ is in effect by
using an explicit glob qualifier of the form ‘(#q)’ at the end of the
string.  A normal glob qualifier expression may appear between the ‘q’
and the closing parenthesis; if none appears the expression has no
effect beyond causing filename generation.  The results of filename
generation are joined together to form a single word, as with the
results of other forms of expansion.

This special use of filename generation is only available with the ‘[[’
syntax.  If the condition occurs within the ‘[’ or ‘test’ builtin
commands then globbing occurs instead as part of normal command line
expansion before the condition is evaluated.  In this case it may
generate multiple words which are likely to confuse the syntax of the
test command.

For example,

      [[ -n file*(#qN) ]]

produces status zero if and only if there is at least one file in the
current directory beginning with the string ‘file’.  The globbing
qualifier ‘N’ ensures that the expression is empty if there is no
matching file.

Pattern metacharacters are active for the PATTERN arguments; the
patterns are the same as those used for filename generation, see *note
Filename Generation: 17, but there is no special behaviour of ‘/’ nor
initial dot, and the patterns ‘**/’ and ‘***/’ behave the same as ‘*/’,
in which the ‘*’ has its standard behaviour but may also match further
‘/’ characters.  Also, no bare glob qualifiers are allowed, though the
form ((#q):var:‘…’) is allowed as shown above.

In each of the above expressions, if FILE is of the form ‘/dev/fd/’N,
where N is an integer, then the test applied to the open file whose
descriptor number is N, even if the underlying system does not support
the ‘/dev/fd’ directory.

In the forms which do numeric comparison, the expressions EXP undergo
arithmetic expansion as if they were enclosed in ‘$((’…‘))’.

For example, the following:

      [[ ( -f foo || -f bar ) && $report = y* ]] && print File exists.

tests if either file ‘foo’ or file ‘bar’ exists, and if so, if the value
of the parameter ‘report’ begins with ‘y’; if the complete condition is
true, the message ‘File exists.’ is printed.


File: zsh.info,  Node: Prompt Expansion,  Next: Expansion,  Prev: Conditional Expressions,  Up: Top

12 Prompt Expansion
*******************

* Menu:

* Expansion of Prompt Sequences::
* Simple Prompt Escapes::
* Conditional Substrings in Prompts::


File: zsh.info,  Node: Expansion of Prompt Sequences,  Next: Simple Prompt Escapes,  Up: Prompt Expansion

12.1 Expansion of Prompt Sequences
==================================

Prompt sequences undergo a special form of expansion.  This type of
expansion is also available using the ‘-P’ option to the ‘print’
builtin.

If the ‘PROMPT_SUBST’ option is set, the prompt string is first
subjected to ‘parameter expansion’, ‘command substitution’ and
‘arithmetic expansion’.  See

Expansion.

Certain escape sequences may be recognised in the prompt string.

If the ‘PROMPT_BANG’ option is set, a ‘!’ in the prompt is replaced by
the current history event number.  A literal ‘!’ may then be represented
as ‘!!’.

If the ‘PROMPT_PERCENT’ option is set, certain escape sequences that
start with ‘%’ are expanded.  Many escapes (see *note Simple Prompt
Escapes: 57.) are followed by a single character, although some of these
take an optional integer argument that should appear between the ‘%’ and
the next character of the sequence.  More complicated escape sequences
(see *note Conditional Substrings in Prompts: 58.) are available to
provide conditional expansion.


File: zsh.info,  Node: Simple Prompt Escapes,  Next: Conditional Substrings in Prompts,  Prev: Expansion of Prompt Sequences,  Up: Prompt Expansion

12.2 Simple Prompt Escapes
==========================

* Menu:

* Special Characters::
* Login Information::
* Shell State::
* Date and Time::
* Visual Effects::


File: zsh.info,  Node: Special Characters,  Next: Login Information,  Up: Simple Prompt Escapes

12.2.1 Special Characters
-------------------------

‘%%’

     A ‘%’.

‘%)’

     A ‘)’.


File: zsh.info,  Node: Login Information,  Next: Shell State,  Prev: Special Characters,  Up: Simple Prompt Escapes

12.2.2 Login Information
------------------------

‘%l’

     The line (tty) the user is logged in on, without ‘/dev/’ prefix.
     If the name starts with ‘/dev/tty’, that prefix is stripped.

‘%M’

     The full machine hostname.

‘%m’

     The hostname up to the first ‘.’.  An integer may follow the ‘%’ to
     specify how many components of the hostname are desired.  With a
     negative integer, trailing components of the hostname are shown.

‘%n’

     ‘$USERNAME’.

‘%y’

     The line (tty) the user is logged in on, without ‘/dev/’ prefix.
     This does not treat ‘/dev/tty’ names specially.


File: zsh.info,  Node: Shell State,  Next: Date and Time,  Prev: Login Information,  Up: Simple Prompt Escapes

12.2.3 Shell State
------------------

‘%#’

     A ‘#’ if the shell is running with privileges, a ‘%’ if not.
     Equivalent to ‘%(!.#.%%)’.  The definition of ‘privileged’, for
     these purposes, is that either the effective user ID is zero, or,
     if POSIX.1e capabilities are supported, that at least one
     capability is raised in either the Effective or Inheritable
     capability vectors.

‘%?’

     The return status of the last command executed just before the
     prompt.

‘%_’

     The status of the parser, i.e.  the shell constructs (like ‘if’ and
     ‘for’) that have been started on the command line.  If given an
     integer number that many strings will be printed; zero or negative
     or no integer means print as many as there are.  This is most
     useful in prompts ‘PS2’ for continuation lines and ‘PS4’ for
     debugging with the ‘XTRACE’ option; in the latter case it will also
     work non-interactively.

‘%^’

     The status of the parser in reverse.  This is the same as ‘%_’
     other than the order of strings.  It is often used in ‘RPS2’.

‘%d’

‘%/’

     Current working directory.  If an integer follows the ‘%’, it
     specifies a number of trailing components of the current working
     directory to show; zero means the whole path.  A negative integer
     specifies leading components, i.e.  ‘%-1d’ specifies the first
     component.

‘%~’

     As ‘%d’ and ‘%/’, but if the current working directory starts with
     ‘$HOME’, that part is replaced by a ‘~’.  Furthermore, if it has a
     named directory as its prefix, that part is replaced by a ‘~’
     followed by the name of the directory, but only if the result is
     shorter than the full path; see ‘Dynamic’ and ‘Static Named
     Directories’ in *note Filename Expansion: 5d.

‘%e’

     Evaluation depth of the current sourced file, shell function, or
     ‘eval’.  This is incremented or decremented every time the value of
     ‘%N’ is set or reverted to a previous value, respectively.  This is
     most useful for debugging as part of ‘$PS4’.

‘%h’

‘%!’

     Current history event number.

‘%i’

     The line number currently being executed in the script, sourced
     file, or shell function given by ‘%N’.  This is most useful for
     debugging as part of ‘$PS4’.

‘%I’

     The line number currently being executed in the file ‘%x’.  This is
     similar to ‘%i’, but the line number is always a line number in the
     file where the code was defined, even if the code is a shell
     function.

‘%j’

     The number of jobs.

‘%L’

     The current value of ‘$SHLVL’.

‘%N’

     The name of the script, sourced file, or shell function that zsh is
     currently executing, whichever was started most recently.  If there
     is none, this is equivalent to the parameter ‘$0’.  An integer may
     follow the ‘%’ to specify a number of trailing path components to
     show; zero means the full path.  A negative integer specifies
     leading components.

‘%x’

     The name of the file containing the source code currently being
     executed.  This behaves as ‘%N’ except that function and eval
     command names are not shown, instead the file where they were
     defined.

‘%c’

‘%.’

‘%C’

     Trailing component of the current working directory.  An integer
     may follow the ‘%’ to get more than one component.  Unless ‘%C’ is
     used, tilde contraction is performed first.  These are deprecated
     as ‘%c’ and ‘%C’ are equivalent to ‘%1~’ and ‘%1/’, respectively,
     while explicit positive integers have the same effect as for the
     latter two sequences.


File: zsh.info,  Node: Date and Time,  Next: Visual Effects,  Prev: Shell State,  Up: Simple Prompt Escapes

12.2.4 Date and Time
--------------------

‘%D’

     The date in YY‘-’MM‘-’DD format.

‘%T’

     Current time of day, in 24-hour format.

‘%t’

‘%@’

     Current time of day, in 12-hour, am/pm format.

‘%*’

     Current time of day in 24-hour format, with seconds.

‘%w’

     The date in DAY‘-’DD format.

‘%W’

     The date in MM‘/’DD‘/’YY format.

‘%D{’STRING‘}’

     STRING is formatted using the ‘strftime’ function.  See
     ‘strftime(3)’ for more details.  Various zsh extensions provide
     numbers with no leading zero or space if the number is a single
     digit:

     ‘%f’

          a day of the month

     ‘%K’

          the hour of the day on the 24-hour clock

     ‘%L’

          the hour of the day on the 12-hour clock

     In addition, if the system supports the POSIX ‘clock_gettime’ or
     ‘gettimeofday’ system call, ‘%.’ provides decimal fractions of a
     second since the epoch with leading zeroes.  By default three
     decimal places are provided, but a number of digits up to 9 may be
     given following the ‘%’; hence ‘%6.’ outputs microseconds, and
     ‘%9.’ outputs nanoseconds.  (The latter requires a
     nanosecond-precision ‘clock_gettime’; systems lacking this will
     return a value multiplied by the appropriate power of 10.)  A
     typical example of this is the format ‘%D{%H:%M:%S.%.}’.

     The GNU extension ‘%N’ is handled as a synonym for ‘%9.’.

     Additionally, the GNU extension that a ‘-’ between the ‘%’ and the
     format character causes a leading zero or space to be stripped is
     handled directly by the shell for the format characters ‘d’, ‘f’,
     ‘H’, ‘k’, ‘l’, ‘m’, ‘M’, ‘S’ and ‘y’; any other format characters
     are provided to the system’s strftime(3) with any leading ‘-’
     present, so the handling is system dependent.  Further GNU (or
     other) extensions are also passed to strftime(3) and may work if
     the system supports them.


File: zsh.info,  Node: Visual Effects,  Prev: Date and Time,  Up: Simple Prompt Escapes

12.2.5 Visual Effects
---------------------

‘%B’ (‘%b’)

     Start (stop) boldface mode.

‘%E’

     Clear to end of line.

‘%U’ (‘%u’)

     Start (stop) underline mode.

‘%S’ (‘%s’)

     Start (stop) standout mode.

‘%F’ (‘%f’)

     Start (stop) using a different foreground colour, if supported by
     the terminal.  The colour may be specified two ways: either as a
     numeric argument, as normal, or by a sequence in braces following
     the ‘%F’, for example ‘%F{red}’.  In the latter case the values
     allowed are as described for the ‘fg’ ‘zle_highlight’ attribute;
     see *note Character Highlighting: 60.  This means that numeric
     colours are allowed in the second format also.

‘%K’ (‘%k’)

     Start (stop) using a different bacKground colour.  The syntax is
     identical to that for ‘%F’ and ‘%f’.

‘%H’

     Change all character visual attributes using a highlighting
     specification from the ‘.zle.hlgroups’ associative array.  The key
     is specified in following braces so, for example ‘%H{error}’ will
     use the highlighting specification for the ‘error’ group.  If the
     key is not found in the associative array then it has no effect.
     Highlighting specifications are in the same format as for the
     ‘zle_highlight’ parameter.  If the following braces are absent,
     attributes are reset to the defaults.

‘%{...%}’

     Include a string as a literal escape sequence.  The string within
     the braces should not change the cursor position.  Brace pairs can
     nest.

     A positive numeric argument between the ‘%’ and the ‘{’ is treated
     as described for ‘%G’ below.

‘%G’

     Within a ‘%{...%}’ sequence, include a ‘glitch’: that is, assume
     that a single character width will be output.  This is useful when
     outputting characters that otherwise cannot be correctly handled by
     the shell, such as the alternate character set on some terminals.
     The characters in question can be included within a ‘%{...%}’
     sequence together with the appropriate number of ‘%G’ sequences to
     indicate the correct width.  An integer between the ‘%’ and ‘G’
     indicates a character width other than one.  Hence ‘%{’SEQ‘%2G%}’
     outputs SEQ and assumes it takes up the width of two standard
     characters.

     Multiple uses of ‘%G’ accumulate in the obvious fashion; the
     position of the ‘%G’ is unimportant.  Negative integers are not
     handled.

     Note that when prompt truncation is in use it is advisable to
     divide up output into single characters within each ‘%{...%}’ group
     so that the correct truncation point can be found.


File: zsh.info,  Node: Conditional Substrings in Prompts,  Prev: Simple Prompt Escapes,  Up: Prompt Expansion

12.3 Conditional Substrings in Prompts
======================================

‘%v’

     The value of the first element of the ‘psvar’ array parameter.
     Following the ‘%’ with an integer gives that element of the array.
     Negative integers count from the end of the array.

‘%(’X‘.’TRUE-TEXT‘.’FALSE-TEXT‘)’

     Specifies a ternary expression.  The character following the X is
     arbitrary; the same character is used to separate the text for the
     ‘true’ result from that for the ‘false’ result.  This separator may
     not appear in the TRUE-TEXT, except as part of a %-escape sequence.
     A ‘)’ may appear in the FALSE-TEXT as ‘%)’.  TRUE-TEXT and
     FALSE-TEXT may both contain arbitrarily-nested escape sequences,
     including further ternary expressions.

     The left parenthesis may be preceded or followed by a positive
     integer N, which defaults to zero.  A negative integer will be
     multiplied by -1, except as noted below for ‘l’.  The test
     character X may be any of the following:

     ‘!’

          True if the shell is running with privileges.

     ‘#’

          True if the effective uid of the current process is N.

     ‘?’

          True if the exit status of the last command was N.

     ‘_’

          True if at least N shell constructs were started.

     ‘C’

     ‘/’

          True if the current absolute path has at least N elements
          relative to the root directory, hence ‘/’ is counted as 0
          elements.

     ‘c’

     ‘.’

     ‘~’

          True if the current path, with prefix replacement, has at
          least N elements relative to the root directory, hence ‘/’ is
          counted as 0 elements.

     ‘D’

          True if the month is equal to N (January = 0).

     ‘d’

          True if the day of the month is equal to N.

     ‘e’

          True if the evaluation depth is at least N.

     ‘g’

          True if the effective gid of the current process is N.

     ‘j’

          True if the number of jobs is at least N.

     ‘L’

          True if the ‘SHLVL’ parameter is at least N.

     ‘l’

          True if at least N characters have already been printed on the
          current line.  When N is negative, true if at least ‘abs(’N‘)’
          characters remain before the opposite margin (thus the left
          margin for ‘RPROMPT’).

     ‘S’

          True if the ‘SECONDS’ parameter is at least N.

     ‘T’

          True if the time in hours is equal to N.

     ‘t’

          True if the time in minutes is equal to N.

     ‘v’

          True if the array ‘psvar’ has at least N elements.

     ‘V’

          True if element N of the array ‘psvar’ is set and non-empty.

     ‘w’

          True if the day of the week is equal to N (Sunday = 0).

‘%<’STRING‘<’

‘%>’STRING‘>’

‘%[’XSTRING‘]’

     Specifies truncation behaviour for the remainder of the prompt
     string.  The third, deprecated, form is equivalent to ‘%’XSTRINGX,
     i.e.  X may be ‘<’ or ‘>’.  The STRING will be displayed in place
     of the truncated portion of any string; note this does not undergo
     prompt expansion.

     The numeric argument, which in the third form may appear
     immediately after the ‘[’, specifies the maximum permitted length
     of the various strings that can be displayed in the prompt.  In the
     first two forms, this numeric argument may be negative, in which
     case the truncation length is determined by subtracting the
     absolute value of the numeric argument from the number of character
     positions remaining on the current prompt line.  If this results in
     a zero or negative length, a length of 1 is used.  In other words,
     a negative argument arranges that after truncation at least N
     characters remain before the right margin (left margin for
     ‘RPROMPT’).

     The forms with ‘<’ truncate at the left of the string, and the
     forms with ‘>’ truncate at the right of the string.  For example,
     if the current directory is ‘/home/pike’, the prompt ‘%8<..<%/’
     will expand to ‘..e/pike’.  In this string, the terminating
     character (‘<’, ‘>’ or ‘]’), or in fact any character, may be
     quoted by a preceding ‘\’; note when using ‘print -P’, however,
     that this must be doubled as the string is also subject to standard
     ‘print’ processing, in addition to any backslashes removed by a
     double quoted string: the worst case is therefore ‘print -P
     "%<\\\\<<..."’.

     If the STRING is longer than the specified truncation length, it
     will appear in full, completely replacing the truncated string.

     The part of the prompt string to be truncated runs to the end of
     the string, or to the end of the next enclosing group of the ‘%(’
     construct, or to the next truncation encountered at the same
     grouping level (i.e.  truncations inside a ‘%(’ are separate),
     which ever comes first.  In particular, a truncation with argument
     zero (e.g., ‘%<<’) marks the end of the range of the string to be
     truncated while turning off truncation from there on.  For example,
     the prompt ‘%10<...<%~%<<%#’ will print a truncated representation
     of the current directory, followed by a ‘%’ or ‘#’, followed by a
     space.  Without the ‘%<<’, those two characters would be included
     in the string to be truncated.  Note that ‘%-0<<’ is not equivalent
     to ‘%<<’ but specifies that the prompt is truncated at the right
     margin.

     Truncation applies only within each individual line of the prompt,
     as delimited by embedded newlines (if any).  If the total length of
     any line of the prompt after truncation is greater than the
     terminal width, or if the part to be truncated contains embedded
     newlines, truncation behavior is undefined and may change in a
     future version of the shell.  Use
     ‘%-’N‘(l.’TRUE-TEXT‘.’FALSE-TEXT‘)’ to remove parts of the prompt
     when the available space is less than N.


File: zsh.info,  Node: Expansion,  Next: Parameters,  Prev: Prompt Expansion,  Up: Top

13 Expansion
************

* Menu:

* Description::
* History Expansion::
* Process Substitution::
* Parameter Expansion::
* Command Substitution::
* Arithmetic Expansion::
* Brace Expansion::
* Filename Expansion::
* Filename Generation::


File: zsh.info,  Node: Description,  Next: History Expansion,  Up: Expansion

13.1 Description
================

The following types of expansions are performed in the indicated order
in five steps:

‘History Expansion’

     This is performed only in interactive shells.

‘Alias Expansion’

     Aliases are expanded immediately before the command line is parsed
     as explained in *note Aliasing: 65.

‘Process Substitution’

‘Parameter Expansion’

‘Command Substitution’

‘Arithmetic Expansion’

‘Brace Expansion’

     These five are performed in left-to-right fashion.  On each
     argument, any of the five steps that are needed are performed one
     after the other.  Hence, for example, all the parts of parameter
     expansion are completed before command substitution is started.
     After these expansions, all unquoted occurrences of the characters
     ‘\,’’ and ‘"’ are removed.

‘Filename Expansion’

     If the ‘SH_FILE_EXPANSION’ option is set, the order of expansion is
     modified for compatibility with ‘sh’ and ‘ksh’.  In that case
     ‘filename expansion’ is performed immediately after ‘alias
     expansion’, preceding the set of five expansions mentioned above.

‘Filename Generation’

     This expansion, commonly referred to as ‘globbing’, is always done
     last.

The following sections explain the types of expansion in detail.


File: zsh.info,  Node: History Expansion,  Next: Process Substitution,  Prev: Description,  Up: Expansion

13.2 History Expansion
======================

History expansion allows you to use words from previous command lines in
the command line you are typing.  This simplifies spelling corrections
and the repetition of complicated commands or arguments.

Immediately before execution, each command is saved in the history list,
the size of which is controlled by the ‘HISTSIZE’ parameter.  The one
most recent command is always retained in any case.  Each saved command
in the history list is called a history ‘event’ and is assigned a
number, beginning with 1 (one) when the shell starts up.  The history
number that you may see in your prompt (see ‘%h’ or ‘%!’ prompt escape
described in *note Simple Prompt Escapes: 67.) is the number that is to
be assigned to the ‘next’ command.

* Menu:

* Overview::
* Event Designators::
* Word Designators::
* Modifiers::


File: zsh.info,  Node: Overview,  Next: Event Designators,  Up: History Expansion

13.2.1 Overview
---------------

A history expansion begins with the first character of the ‘histchars’
parameter, which is ‘!’ by default, and may occur anywhere on the
command line, including inside double quotes (but not inside single
quotes ‘'...'’ or C-style quotes ‘$'...'’ nor when escaped with a
backslash).

The first character is followed by an optional event designator (see
*note Event Designators: 69.) and then an optional word designator
(*note Word Designators: 6a.); if neither of these designators is
present, no history expansion occurs.

Input lines containing history expansions are echoed after being
expanded, but before any other expansions take place and before the
command is executed.  It is this expanded form that is recorded as the
history event for later references.

History expansions do not nest.

By default, a history reference with no event designator refers to the
same event as any preceding history reference on that command line; if
it is the only history reference in a command, it refers to the previous
command.  ..  index:: single: CSH_JUNKIE_HISTORY, use of; Program

However, if the option ‘CSH_JUNKIE_HISTORY’ is set, then every history
reference with no event specification ‘always’ refers to the previous
command.

For example, ‘!’ is the event designator for the previous command, so
‘!!:1’ always refers to the first word of the previous command, and
‘!!$’ always refers to the last word of the previous command.  With
‘CSH_JUNKIE_HISTORY’ set, then ‘!:1’ and ‘!$’ function in the same
manner as ‘!!:1’ and ‘!!$’, respectively.  Conversely, if
‘CSH_JUNKIE_HISTORY’ is unset, then ‘!:1’ and ‘!$’ refer to the first
and last words, respectively, of the same event referenced by the
nearest other history reference preceding them on the current command
line, or to the previous command if there is no preceding reference.

The character sequence ‘^’FOO‘^’BAR (where ‘^’ is actually the second
character of the ‘histchars’ parameter) repeats the last command,
replacing the string FOO with BAR.  More precisely, the sequence
‘^’FOO‘^’BAR‘^’ is synonymous with ‘!!:s^’FOO‘^’BAR‘^’, hence other
modifiers (see *note Modifiers: 6b.) may follow the final ‘^’.  In
particular, ‘^’FOO‘^’BAR‘^:G’ performs a global substitution.

If the shell encounters the character sequence ‘!"’ in the input, the
history mechanism is temporarily disabled until the current list (see
‘zshmisc’) is fully parsed.  The ‘!"’ is removed from the input, and any
subsequent ‘!’ characters have no special significance.

A less convenient but more comprehensible form of command history
support is provided by the ‘fc’ builtin.


File: zsh.info,  Node: Event Designators,  Next: Word Designators,  Prev: Overview,  Up: History Expansion

13.2.2 Event Designators
------------------------

An event designator is a reference to a command-line entry in the
history list.  In the list below, remember that the initial ‘\`!'’ in
each item may be changed to another character by setting the ‘histchars’
parameter.

‘!’

     Start a history expansion, except when followed by a blank,
     newline, ‘=’ or ‘(’.  If followed immediately by a word designator
     ( ..  only:: man

          see

     *note Word Designators: 6a.), this forms a history reference with
     no event designator ( ..  only:: man

          see

     *note Overview: 68.).

‘!!’

     Refer to the previous command.  By itself, this expansion repeats
     the previous command.

‘!’N

     Refer to command-line N.

‘!-’N

     Refer to the current command-line minus N.

‘!’STR

     Refer to the most recent command starting with STR.

‘!?’STR[‘?’]

     Refer to the most recent command containing STR.  The trailing ‘?’
     is necessary if this reference is to be followed by a modifier or
     followed by any text that is not to be considered part of STR.

‘!#’

     Refer to the current command line typed in so far.  The line is
     treated as if it were complete up to and including the word before
     the one with the ‘!#’ reference.

‘!{...}’

     Insulate a history reference from adjacent characters (if
     necessary).


File: zsh.info,  Node: Word Designators,  Next: Modifiers,  Prev: Event Designators,  Up: History Expansion

13.2.3 Word Designators
-----------------------

A word designator indicates which word or words of a given command line
are to be included in a history reference.  A ‘:’ usually separates the
event specification from the word designator.  It may be omitted only if
the word designator begins with a ‘^’, ‘$’, ‘*’, ‘-’ or ‘%’.  Word
designators include:

‘0’

     The first input word (command).

N

     The Nth argument.

‘^’

     The first argument.  That is, ‘1’.

‘$’

     The last argument.

‘%’

     The word matched by (the most recent) ‘?’STR search.

X‘-’Y

     A range of words; X defaults to ‘0’.

‘*’

     All the arguments, or a null value if there are none.

X‘*’

     Abbreviates X‘-$’.

X‘-’

     Like X‘*’ but omitting word ‘$’.

Note that a ‘%’ word designator works only when used in one of ‘!%’,
‘!:%’ or ‘!?’STR‘?:%’, and only when used after a ‘!?’ expansion
(possibly in an earlier command).  Anything else results in an error,
although the error may not be the most obvious one.


File: zsh.info,  Node: Modifiers,  Prev: Word Designators,  Up: History Expansion

13.2.4 Modifiers
----------------

After the optional word designator, you can add a sequence of one or
more of the following modifiers, each preceded by a ‘:’.  These
modifiers also work on the result of ‘filename generation’ and
‘parameter expansion’, except where noted.

‘a’

     Turn a file name into an absolute path: prepends the current
     directory, if necessary; remove ‘.’ path segments; and remove ‘..’
     path segments and the segments that immediately precede them.

     This transformation is agnostic about what is in the filesystem,
     i.e.  is on the logical, not the physical directory.  It takes
     place in the same manner as when changing directories when neither
     of the options ‘CHASE_DOTS’ or ‘CHASE_LINKS’ is set.  For example,
     ‘/before/here/../after’ is always transformed to ‘/before/after’,
     regardless of whether ‘/before/here’ exists or what kind of object
     (dir, file, symlink, etc.)  it is.

‘A’

     Turn a file name into an absolute path as the ‘a’ modifier does,
     and ‘then’ pass the result through the ‘realpath(3)’ library
     function to resolve symbolic links.

     Note: on systems that do not have a ‘realpath(3)’ library function,
     symbolic links are not resolved, so on those systems ‘a’ and ‘A’
     are equivalent.

     Note: ‘foo:A’ and ‘realpath(foo)’ are different on some inputs.
     For ‘realpath(foo)’ semantics, see the ‘`P’‘ modifier.

‘c’

     Resolve a command name into an absolute path by searching the
     command path given by the ‘PATH’ variable.  This does not work for
     commands containing directory parts.  Note also that this does not
     usually work as a glob qualifier unless a file of the same name is
     found in the current directory.

‘e’

     Remove all but the part of the filename extension following the
     ‘.’; see the definition of the filename extension in the
     description of the ‘r’ modifier below.  Note that according to that
     definition the result will be empty if the string ends with a ‘.’.

‘h’ [ DIGITS ]

     Remove a trailing pathname component, shortening the path by one
     directory level: this is the ‘head’ of the pathname.  This works
     like ‘dirname’.  If the ‘h’ is followed immediately (with no spaces
     or other separator) by any number of decimal digits, and the value
     of the resulting number is non-zero, that number of leading
     components is preserved instead of the final component being
     removed.  In an absolute path the leading ‘/’ is the first
     component, so, for example, if ‘var=/my/path/to/something’, then
     ‘${var:h3}’ substitutes ‘/my/path’.  Consecutive ‘/’s are treated
     the same as a single ‘/’.  In parameter substitution, digits may
     only be used if the expression is in braces, so for example the
     short form substitution ‘$var:h2’ is treated as ‘${var:h}2’, not as
     ‘${var:h2}’.  No restriction applies to the use of digits in
     history substitution or globbing qualifiers.  If more components
     are requested than are present, the entire path is substituted (so
     this does not trigger a ‘failed modifier’ error in history
     expansion).

‘l’

     Convert the words to all lowercase.

‘p’

     Print the new command but do not execute it.  Only works with
     history expansion.

‘P’

     Turn a file name into an absolute path, like ‘realpath(3)’.  The
     resulting path will be absolute, will refer to the same directory
     entry as the input filename, and none of its components will be
     symbolic links or equal to ‘.’ or ‘..’.

     Unlike ‘realpath(3)’, non-existent trailing components are
     permitted and preserved.

‘q’

     Quote the substituted words, escaping further substitutions.  Works
     with history expansion and parameter expansion, though for
     parameters it is only useful if the resulting text is to be
     re-evaluated such as by ‘eval’.

‘Q’

     Remove one level of quotes from the substituted words.

‘r’

     Remove a filename extension leaving the root name.  Strings with no
     filename extension are not altered.  A filename extension is a ‘.’
     followed by any number of characters (including zero) that are
     neither ‘.’ nor ‘/’ and that continue to the end of the string.
     For example, the extension of ‘foo.orig.c’ is ‘.c’, and ‘dir.c/foo’
     has no extension.

‘s/’L‘/’R[‘/’]

‘S/’L‘/’R[‘/’]

     Substitute R for L as described below.  The substitution is done
     only for the first string that matches L.  For arrays and for
     filename generation, this applies to each word of the expanded
     text.  See below for further notes on substitutions.

     The forms ‘gs/’L‘/’R and ‘s/’L‘/’R‘/:G’ perform global
     substitution, i.e.  substitute every occurrence of R for L.  Note
     that the ‘g’ or ‘:G’ must appear in exactly the position shown.

     The use of ‘S’ instead of ‘s’ is identical except that the source
     is treated as a pattern, just as if the option ‘HIST_SUBST_PATTERN’
     were set.

     See further notes on this form of substitution below.

‘&’

     Repeat the previous ‘s’ or ‘S’ substitution, whichever was most
     recent.  Like ‘s’ and ‘S’, may be preceded immediately by a ‘g’.
     In parameter expansion the ‘&’ must appear inside braces, and in
     filename generation it must be quoted with a backslash.

‘t’ [ DIGITS ]

     Remove all leading pathname components, leaving the final component
     (tail).  This works like ‘basename’.  Any trailing slashes are
     first removed.  Decimal digits are handled as described above for
     (h), but in this case that number of trailing components is
     preserved instead of the default 1; 0 is treated the same as 1.

‘u’

     Convert the words to all uppercase.

‘x’

     Like ‘q’, but break into words at whitespace.  Does not work with
     parameter expansion.

The ‘s/’L‘/’R‘/’ substitution works as follows.  By default the
left-hand side of substitutions are not patterns, but character strings.
Any character can be used as the delimiter in place of ‘/’.  A backslash
quotes the delimiter character.  The character ‘&’, in the
right-hand-side R, is replaced by the text from the left-hand-side L.
The ‘&’ can be quoted with a backslash.  A null L uses the previous
string either from the previous L or from the contextual scan string S
from ‘!?’S.  You can omit the rightmost delimiter if a newline
immediately follows R; the rightmost ‘?’ in a context scan can similarly
be omitted.  Note the same record of the last L and R is maintained
across all forms of expansion.

Note that if a ‘&’ is used within glob qualifiers an extra backslash is
needed as a ‘&’ is a special character in this case.

Also note that the order of expansions affects the interpretation of L
and R.  When used in a history expansion, which occurs before any other
expansions, L and R are treated as literal strings (except as explained
for ‘HIST_SUBST_PATTERN’ below).  When used in parameter expansion, the
replacement of R into the parameter’s value is done first, and then any
additional process, parameter, command, arithmetic, or brace references
are applied, which may evaluate those substitutions and expansions more
than once if L appears more than once in the starting value.  When used
in a glob qualifier, any substitutions or expansions are performed once
at the time the qualifier is parsed, even before the ‘:s’ expression
itself is divided into L and R sides.

If the option ‘HIST_SUBST_PATTERN’ is set or the original substitution
was started with a capital ‘S’, L is treated as a pattern of the usual
form described in *note Filename Generation: 17.  This can be used in
all the places where modifiers are available; note, however, that in
globbing qualifiers parameter substitution has already taken place, so
parameters in the replacement string should be quoted to ensure they are
replaced at the correct time.  Note also that complicated patterns used
in globbing qualifiers may need the extended glob qualifier notation
‘(#q:s/’…‘/’…‘/)’ in order for the shell to recognize the expression as
a glob qualifier.  Further, note that bad patterns in the substitution
are not subject to the ‘NO_BAD_PATTERN’ option so will cause an error.

When ‘HIST_SUBST_PATTERN’ is set, L may start with a ‘#’ to indicate
that the pattern must match at the start of the string to be
substituted, and a ‘%’ may appear at the start or after an ‘#’ to
indicate that the pattern must match at the end of the string to be
substituted.  The ‘%’ or ‘#’ may be quoted with two backslashes.

For example, the following piece of filename generation code with the
‘EXTENDED_GLOB’ option:

      print -r -- *.c(#q:s/#%(#b)s(*).c/'S${match[1]}.C'/)

takes the expansion of ‘*.c’ and applies the glob qualifiers in the
‘(#q’…‘)’ expression, which consists of a substitution modifier anchored
to the start and end of each word (‘#%’).  This turns on backreferences
(‘(#b)’), so that the parenthesised subexpression is available in the
replacement string as ‘${match[1]}’.  The replacement string is quoted
so that the parameter is not substituted before the start of filename
generation.

The following ‘f’, ‘F’, ‘w’ and ‘W’ modifiers work only with parameter
expansion and filename generation.  They are listed here to provide a
single point of reference for all modifiers.

‘f’

     Repeats the immediately (without a colon) following modifier until
     the resulting word doesn’t change any more.

‘F:’EXPR‘:’

     Like ‘f’, but repeats only N times if the expression EXPR evaluates
     to N.  Any character can be used instead of the ‘:’; if ‘(’, ‘[’,
     or ‘{’ is used as the opening delimiter, the closing delimiter
     should be ‘‘)’’, ‘]’, or ‘}’, respectively.

‘w’

     Makes the immediately following modifier work on each word in the
     string.

‘W:’SEP‘:’

     Like ‘w’ but words are considered to be the parts of the string
     that are separated by SEP.  Any character can be used instead of
     the ‘:’; opening parentheses are handled specially, see above.


File: zsh.info,  Node: Process Substitution,  Next: Parameter Expansion,  Prev: History Expansion,  Up: Expansion

13.3 Process Substitution
=========================

Each part of a command argument that takes the form ‘<(’LIST‘)’,
‘>(’LIST‘)’ or ‘=(’LIST‘)’ is subject to process substitution.  The
expression may be preceded or followed by other strings except that, to
prevent clashes with commonly occurring strings and patterns, the last
form must occur at the start of a command argument, and the forms are
only expanded when first parsing command or assignment arguments.
Process substitutions may be used following redirection operators; in
this case, the substitution must appear with no trailing string.

Note that ‘<<(’LIST‘)’ is not a special syntax; it is equivalent to ‘<
<(’LIST‘)’, redirecting standard input from the result of process
substitution.  Hence all the following documentation applies.  The
second form (with the space) is recommended for clarity.

In the case of the ‘<’ or ‘>’ forms, the shell runs the commands in LIST
as a subprocess of the job executing the shell command line.  If the
system supports the ‘/dev/fd’ mechanism, the command argument is the
name of the device file corresponding to a file descriptor; otherwise,
if the system supports named pipes (FIFOs), the command argument will be
a named pipe.  If the form with ‘>’ is selected then writing on this
special file will provide input for LIST.  If ‘<’ is used, then the file
passed as an argument will be connected to the output of the LIST
process.  For example,

      paste <(cut -f1 FILE1) <(cut -f3 FILE2) |
      tee >(PROCESS1``) >(:var:`process2`) >/dev/null``

cuts fields 1 and 3 from the files FILE1 and FILE2 respectively, pastes
the results together, and sends it to the processes PROCESS1 and
PROCESS2.

If ‘=(’…‘)’ is used instead of ‘<(’…‘)’, then the file passed as an
argument will be the name of a temporary file containing the output of
the LIST process.  This may be used instead of the ‘<’ form for a
program that expects to lseek (see ‘lseek(2)’) on the input file.

There is an optimisation for substitutions of the form ‘=(<<<’ARG‘)’,
where ARG is a single-word argument to the here-string redirection
‘<<<’.  This form produces a file name containing the value of ARG after
any substitutions have been performed.  This is handled entirely within
the current shell.  This is effectively the reverse of the special form
‘$(<’ARG‘)’ which treats ARG as a file name and replaces it with the
file’s contents.

The ‘=’ form is useful as both the ‘/dev/fd’ and the named pipe
implementation of ‘<(’…‘)’ have drawbacks.  In the former case, some
programmes may automatically close the file descriptor in question
before examining the file on the command line, particularly if this is
necessary for security reasons such as when the programme is running
setuid.  In the second case, if the programme does not actually open the
file, the subshell attempting to read from or write to the pipe will (in
a typical implementation, different operating systems may have different
behaviour) block for ever and have to be killed explicitly.  In both
cases, the shell actually supplies the information using a pipe, so that
programmes that expect to lseek (see ‘lseek(2)’) on the file will not
work.

Also note that the previous example can be more compactly and
efficiently written (provided the ‘MULTIOS’ option is set) as:

      paste <(cut -f1 FILE1) <(cut -f3 FILE2)
      > >(PROCESS1) > >(PROCESS2)

The shell uses pipes instead of FIFOs to implement the latter two
process substitutions in the above example.

There is an additional problem with ‘>(’PROCESS‘)’; when this is
attached to an external command, the parent shell does not wait for
PROCESS to finish and hence an immediately following command cannot rely
on the results being complete.  The problem and solution are the same as
described in the section *note Multios: 6c.  Hence in a simplified
version of the example above:

      paste <(cut -f1 FILE1) <(cut -f3 FILE2) > >(PROCESS)

(note that no ‘MULTIOS’ are involved), PROCESS will be run
asynchronously as far as the parent shell is concerned.  The workaround
is:

      { paste <(cut -f1 FILE1) <(cut -f3 FILE2) } > >(PROCESS)

The extra processes here are spawned from the parent shell which will
wait for their completion.

Another problem arises any time a job with a substitution that requires
a temporary file is disowned by the shell, including the case where ‘&!’
or ‘&|’ appears at the end of a command containing a substitution.  In
that case the temporary file will not be cleaned up as the shell no
longer has any memory of the job.  A workaround is to use a subshell,
for example,

      (mycmd =(myoutput)) &!

as the forked subshell will wait for the command to finish then remove
the temporary file.

A general workaround to ensure a process substitution endures for an
appropriate length of time is to pass it as a parameter to an anonymous
shell function (a piece of shell code that is run immediately with
function scope).  For example, this code:

      () {
         print File $1:
         cat $1
      } =(print This be the verse)

outputs something resembling the following

      File /tmp/zsh6nU0kS:
      This be the verse

The temporary file created by the process substitution will be deleted
when the function exits.


File: zsh.info,  Node: Parameter Expansion,  Next: Command Substitution,  Prev: Process Substitution,  Up: Expansion

13.4 Parameter Expansion
========================

The character ‘$’ is used to introduce parameter expansions.  See
‘zshparam’ for a description of parameters, including arrays,
associative arrays, and subscript notation to access individual array
elements.

Note in particular the fact that words of unquoted parameters are not
automatically split on whitespace unless the option ‘SH_WORD_SPLIT’ is
set; see references to this option below for more details.  This is an
important difference from other shells.  However, as in other shells,
null words are elided from unquoted parameters’ expansions.

With default options, after the assignments:

      array=("first word" "" "third word")
      scalar="only word"

then ‘$array’ substitutes two words, ‘first word’ and ‘third word’,
and‘‘ $scalar ‘substitutes a single word’ only word‘‘.  Note that second
element of ‘array’ was elided.  Scalar parameters can be elided too if
their value is null (empty).  To avoid elision, use quoting as follows:
‘"$scalar"’ for scalars and ‘"${array[@]}"’ or ‘"${(@)array}"’ for
arrays.  (The last two forms are equivalent.)

Parameter expansions can involve ‘flags’, as in ‘${(@kv)aliases}’, and
other operators, such as ‘${PREFIX:-"/usr/local"}’.  Parameter
expansions can also be nested.  These topics will be introduced below.
The full rules are complicated and are noted at the end.

Parameter expansions may optionally include a ‘namespace’ prefix in the
format ‘.’IDENTIFIER‘.’ This currently has no special meaning to the
shell, but provides a convenient means of grouping related parameters.
Expansions using a namespace ‘must’ include braces (‘{’ and ‘}’) as
shown in the descriptions below, and only one namespace prefix is
allowed.

In the expansions discussed below that require a pattern, the form of
the pattern is the same as that used for filename generation; see *note
Filename Generation: 17.  Note that these patterns, along with the
replacement text of any substitutions, are themselves subject to
parameter expansion, command substitution, and arithmetic expansion.

In addition to the following operations, the colon modifiers described
in *note Modifiers: 6b. in *note History Expansion: 66. can be applied:
for example, ‘${i:s/foo/bar/}’ performs string substitution on the
expansion of parameter ‘$i’.

In the following descriptions, WORD refers to a single word substituted
on the command line, not necessarily a space delimited word.  The
reference to NAME in each description presumes any optional namespace
prefix.

‘${’NAME‘}’

     The value, if any, of the parameter NAME is substituted.  The
     braces are required if the expansion is to be followed by a letter,
     digit, or underscore that is not to be interpreted as part of NAME.
     In addition, more complicated forms of substitution usually require
     the braces to be present; exceptions, which only apply if the
     option ‘KSH_ARRAYS’ is not set, are a single subscript or any colon
     modifiers appearing after the name, or any of the characters ‘^’,
     ‘=’, ‘~’, ‘#’ or ‘+’ appearing before the name, all of which work
     with or without braces.

     If NAME is an array parameter, and the ‘KSH_ARRAYS’ option is not
     set, then the value of each element of NAME is substituted, one
     element per word.  Otherwise, the expansion results in one word
     only; with ‘KSH_ARRAYS’, this is the first element of an array.  No
     field splitting is done on the result unless the ‘SH_WORD_SPLIT’
     option is set.  See also the flags ‘=’ and ‘s:’STRING‘:’.

‘${+’NAME‘}’

     If NAME is the name of a set parameter ‘1’ is substituted,
     otherwise ‘0’ is substituted.

‘${’NAME‘-’WORD‘}’

‘${’NAME‘:-’WORD‘}’

     If NAME is set, or in the second form is non-null, then substitute
     its value; otherwise substitute WORD.  In the second form NAME may
     be omitted, in which case WORD is always substituted.

‘${’NAME‘+’WORD‘}’

‘${’NAME‘:+’WORD‘}’

     If NAME is set, or in the second form is non-null, then substitute
     WORD; otherwise substitute nothing.

‘${’NAME‘=’WORD‘}’

‘${’NAME‘:=’WORD‘}’

‘${’NAME‘::=’WORD‘}’

     In the first form, if NAME is unset then set it to WORD; in the
     second form, if NAME is unset or null then set it to WORD; and in
     the third form, unconditionally set NAME to WORD.  In all forms,
     the value of NAME is then substituted.

‘${’NAME‘?’WORD‘}’

‘${’NAME‘:?’WORD‘}’

     In the first form, if NAME is set, or in the second form if NAME is
     both set and non-null, then substitute its value; otherwise, print
     WORD and exit from the shell.  Interactive shells instead return to
     the prompt.  If WORD is omitted, then a standard message is
     printed.  Note that WORD is expanded even though its value is not
     substituted onto the command line.

In any of the above expressions that test a variable and substitute an
alternate WORD, note that you can use standard shell quoting in the WORD
value to selectively override the splitting done by the ‘SH_WORD_SPLIT’
option and the ‘=’ flag, but not splitting by the ‘s:’STRING‘:’ flag.

In the following expressions, when NAME is an array and the substitution
is not quoted, or if the ‘(@)’ flag or the NAME‘[@]’ syntax is used,
matching and replacement is performed on each array element separately.

‘${’NAME‘#’PATTERN‘}’

‘${’NAME‘##’PATTERN‘}’

     If the PATTERN matches the beginning of the value of NAME, then
     substitute the value of NAME with the matched portion deleted;
     otherwise, just substitute the value of NAME.  In the first form,
     the smallest matching pattern is preferred; in the second form, the
     largest matching pattern is preferred.

‘${’NAME‘%’PATTERN‘}’

‘${’NAME‘%%’PATTERN‘}’

     If the PATTERN matches the end of the value of NAME, then
     substitute the value of NAME with the matched portion deleted;
     otherwise, just substitute the value of NAME.  In the first form,
     the smallest matching pattern is preferred; in the second form, the
     largest matching pattern is preferred.

‘${’NAME‘:#’PATTERN‘}’

     If the PATTERN matches the value of NAME, then substitute the empty
     string; otherwise, just substitute the value of NAME.  If NAME is
     an array the matching array elements are removed (use the ‘(M)’
     flag to remove the non-matched elements).

‘${’NAME‘:|’ARRAYNAME‘}’

     If ARRAYNAME is the name (N.B., not contents) of an array variable,
     then any elements contained in ARRAYNAME are removed from the
     substitution of NAME.  If the substitution is scalar, either
     because NAME is a scalar variable or the expression is quoted, the
     elements of ARRAYNAME are instead tested against the entire
     expression.

‘${’NAME‘:*’ARRAYNAME‘}’

     Similar to the preceding substitution, but in the opposite sense,
     so that entries present in both the original substitution and as
     elements of ARRAYNAME are retained and others removed.

‘${’NAME‘:^’ARRAYNAME‘}’

‘${’NAME‘:^^’ARRAYNAME‘}’

     Zips two arrays, such that the output array is twice as long as the
     shortest (longest for ‘:^^’) of ‘name’ and ‘arrayname’, with the
     elements alternatingly being picked from them.  For ‘:^’, if one of
     the input arrays is longer, the output will stop when the end of
     the shorter array is reached.  Thus,

           a=(1 2 3 4); b=(a b); print ${a:^b}

     will output ‘1 a 2 b’.  For ‘:^^’, then the input is repeated until
     all of the longer array has been used up and the above will output
     ‘1 a 2 b 3 a 4 b’.

     Either or both inputs may be a scalar, they will be treated as an
     array of length 1 with the scalar as the only element.  If either
     array is empty, the other array is output with no extra elements
     inserted.

     Currently the following code will output ‘a b’ and ‘1’ as two
     separate elements, which can be unexpected.  The second print
     provides a workaround which should continue to work if this is
     changed.

           a=(a b); b=(1 2); print -l "${a:^b}"; print -l "${${a:^b}}"

‘${’NAME‘:’OFFSET‘}’

‘${’NAME‘:’OFFSET‘:’LENGTH‘}’

     This syntax gives effects similar to parameter subscripting in the
     form ‘$’NAME‘[’START‘,’END‘]’, but is compatible with other shells;
     note that both OFFSET and LENGTH are interpreted differently from
     the components of a subscript.

     If OFFSET is non-negative, then if the variable NAME is a scalar
     substitute the contents starting OFFSET characters from the first
     character of the string, and if NAME is an array substitute
     elements starting OFFSET elements from the first element.  If
     LENGTH is given, substitute that many characters or elements,
     otherwise the entire rest of the scalar or array.

     A positive OFFSET is always treated as the offset of a character or
     element in NAME from the first character or element of the array
     (this is different from native zsh subscript notation).  Hence 0
     refers to the first character or element regardless of the setting
     of the option ‘KSH_ARRAYS’.

     A negative offset counts backwards from the end of the scalar or
     array, so that -1 corresponds to the last character or element, and
     so on.

     When positive, LENGTH counts from the OFFSET position toward the
     end of the scalar or array.  When negative, LENGTH counts back from
     the end.  If this results in a position smaller than OFFSET, a
     diagnostic is printed and nothing is substituted.

     The option ‘MULTIBYTE’ is obeyed, i.e.  the offset and length count
     multibyte characters where appropriate.

     OFFSET and LENGTH undergo the same set of shell substitutions as
     for scalar assignment; in addition, they are then subject to
     arithmetic evaluation.  Hence, for example

           print ${foo:3}
           print ${foo: 1 + 2}
           print ${foo:$(( 1 + 2))}
           print ${foo:$(echo 1 + 2)}

     all have the same effect, extracting the string starting at the
     fourth character of ‘$foo’ if the substitution would otherwise
     return a scalar, or the array starting at the fourth element if
     ‘$foo’ would return an array.  Note that with the option
     ‘KSH_ARRAYS’ ‘$foo’ always returns a scalar (regardless of the use
     of the offset syntax) and a form such as ‘${foo[*]:3}’ is required
     to extract elements of an array named ‘foo’.

     If OFFSET is negative, the ‘-’ may not appear immediately after the
     ‘:’ as this indicates the ‘${’NAME‘:-’WORD‘}’ form of substitution.
     Instead, a space may be inserted before the ‘-’.  Furthermore,
     neither OFFSET nor LENGTH may begin with an alphabetic character or
     ‘&’ as these are used to indicate history-style modifiers.  To
     substitute a value from a variable, the recommended approach is to
     precede it with a ‘$’ as this signifies the intention (parameter
     substitution can easily be rendered unreadable); however, as
     arithmetic substitution is performed, the expression ‘${var: offs}’
     does work, retrieving the offset from ‘$offs’.

     For further compatibility with other shells there is a special case
     for array offset 0.  This usually accesses the first element of the
     array.  However, if the substitution refers to the positional
     parameter array, e.g.  ‘$@’ or ‘$*’, then offset 0 instead refers
     to ‘$0’, offset 1 refers to ‘$1’, and so on.  In other words, the
     positional parameter array is effectively extended by prepending
     ‘$0’.  Hence ‘${*:0:1}’ substitutes ‘$0’ and ‘${*:1:1}’ substitutes
     ‘$1’.

‘${’NAME‘/’PATTERN‘/’REPL‘}’

‘${’NAME‘//’PATTERN‘/’REPL‘}’

‘${’NAME‘:/’PATTERN‘/’REPL‘}’

     Replace the longest possible match of PATTERN in the expansion of
     parameter NAME by string REPL.  The first form replaces just the
     first occurrence, the second form all occurrences, and the third
     form replaces only if PATTERN matches the entire string.  Both
     PATTERN and REPL are subject to double-quoted substitution, so that
     expressions like ‘${name/$opat/$npat}’ will work, but obey the
     usual rule that pattern characters in ‘$opat’ are not treated
     specially unless either the option ‘GLOB_SUBST’ is set, or ‘$opat’
     is instead substituted as ‘${~opat}’.

     The PATTERN may begin with a ‘#’, in which case the PATTERN must
     match at the start of the string, or ‘%’, in which case it must
     match at the end of the string, or ‘#%’ in which case the PATTERN
     must match the entire string.  The REPL may be an empty string, in
     which case the final ‘/’ may also be omitted.  To quote the final
     ‘/’ in other cases it should be preceded by a single backslash;
     this is not necessary if the ‘/’ occurs inside a substituted
     parameter.  Note also that the ‘#’, ‘%’ and ‘`#%’ are not active if
     they occur inside a substituted parameter, even at the start.

     If, after quoting rules apply, ‘${’NAME‘}’ expands to an array, the
     replacements act on each element individually.  Note also the
     effect of the ‘I’ and ‘S’ parameter expansion flags below; however,
     the flags ‘M’, ‘R’, ‘B’, ‘E’ and ‘N’ are not useful.

     For example,

           foo="twinkle twinkle little star" sub="t*e" rep="spy"
           print ${foo//${~sub}/$rep}
           print ${(S)foo//${~sub}/$rep}

     Here, the ‘~’ ensures that the text of ‘$sub’ is treated as a
     pattern rather than a plain string.  In the first case, the longest
     match for ‘t*e’ is substituted and the result is ‘spy star’, while
     in the second case, the shortest matches are taken and the result
     is ‘spy spy lispy star’.

‘${#’SPEC‘}’

     If SPEC is one of the above substitutions, substitute the length in
     characters of the result instead of the result itself.  If SPEC is
     an array expression, substitute the number of elements of the
     result.  This has the side-effect that joining is skipped even in
     quoted forms, which may affect other sub-expressions in SPEC.  Note
     that ‘^’, ‘=’, and ‘~’, below, must appear to the left of ‘#’ when
     these forms are combined.

     If the option ‘POSIX_IDENTIFIERS’ is not set, and SPEC is a simple
     name, then the braces are optional; this is true even for special
     parameters so e.g.  ‘$#-’ and ‘$#*’ take the length of the string
     ‘$-’ and the array ‘$*’ respectively.  If ‘POSIX_IDENTIFIERS’ is
     set, then braces are required for the ‘#’ to be treated in this
     fashion.

‘${^’SPEC‘}’

‘${^^’SPEC‘}’

     Turn on the ‘RC_EXPAND_PARAM’ option for the evaluation of SPEC; if
     the ‘^’ is doubled, turn it off.  When this option is set, array
     expansions of the form FOO‘${’XX‘}’BAR, where the parameter XX is
     set to ‘(’A B C‘)’, are substituted with FOOABAR FOOBBAR FOOCBAR
     instead of the default FOOA B CBAR.  Note that an empty array will
     therefore cause all arguments to be removed.

     Internally, each such expansion is converted into the equivalent
     list for brace expansion.  E.g., ‘${^var}’ becomes
     ‘{$var[1],$var[2],...}’, and is processed as described in Brace
     Expansion below: note, however, the expansion happens immediately,
     with any explicit brace expansion happening later.  If word
     splitting is also in effect the ‘$var[’N‘]’ may themselves be split
     into different list elements.

‘${=’SPEC‘}’

‘${==’SPEC‘}’

     Perform word splitting using the rules for ‘SH_WORD_SPLIT’ during
     the evaluation of SPEC, but regardless of whether the parameter
     appears in double quotes; if the ‘=’ is doubled, turn it off.  ..
     index:: single: IFS, use of; Variable

     This forces parameter expansions to be split into separate words
     before substitution, using ‘IFS’ as a delimiter.  This is done by
     default in most other shells.

     Note that splitting is applied to WORD in the assignment forms of
     SPEC ‘before’ the assignment to NAME is performed.  This affects
     the result of array assignments with the ‘A’ flag.

‘${~’SPEC‘}’

‘${~~’SPEC‘}’

     Turn on the ‘GLOB_SUBST’ option for the evaluation of SPEC; if the
     ‘~’ is doubled, turn it off.  When this option is set, the string
     resulting from the expansion will be interpreted as a pattern
     anywhere that is possible, such as in filename expansion and
     filename generation and pattern-matching contexts like the right
     hand side of the ‘=’ and ‘!=’ operators in conditions.

     In nested substitutions, note that the effect of the ‘~’ applies to
     the result of the current level of substitution.  A surrounding
     pattern operation on the result may cancel it.  Hence, for example,
     if the parameter ‘foo’ is set to ‘*’, ‘${~foo//\*/*.c}’ is
     substituted by the pattern ‘*.c’, which may be expanded by filename
     generation, but ‘${${~foo}//\*/*.c}’ substitutes to the string
     ‘*.c’, which will not be further expanded.

If a ‘${...}’ type parameter expression or a ‘$(...)’ type command
substitution is used in place of NAME above, it is expanded first and
the result is used as if it were the value of NAME.  Thus it is possible
to perform nested operations: ‘${${foo#head}%tail}’ substitutes the
value of ‘$foo’ with both ‘head’ and ‘tail’ deleted.  The form with
‘$(...)’ is often useful in combination with the flags described next;
see the examples below.  Each NAME or nested ‘${...}’ in a parameter
expansion may also be followed by a subscript expression as described in
*note Array Parameters: 1b.

Note that double quotes may appear around nested expressions, in which
case only the part inside is treated as quoted; for example,
‘${(f)"$(foo)"}’ quotes the result of ‘$(foo)’, but the flag ‘(f)’ (see
below) is applied using the rules for unquoted expansions.  Note further
that quotes are themselves nested in this context; for example, in
‘"${(@f)"$(foo)"}"’, there are two sets of quotes, one surrounding the
whole expression, the other (redundant) surrounding the ‘$(foo)’ as
before.

* Menu:

* Parameter Expansion Flags::
* Named References::
* Rules::
* Examples::


File: zsh.info,  Node: Parameter Expansion Flags,  Next: Named References,  Up: Parameter Expansion

13.4.1 Parameter Expansion Flags
--------------------------------

If the opening brace is directly followed by an opening parenthesis, the
string up to the matching closing parenthesis will be taken as a list of
flags.  In cases where repeating a flag is meaningful, the repetitions
need not be consecutive; for example, (‘q%q%q’) means the same thing as
the more readable (‘%%qqq’).  The following flags are supported:

‘!’

     When the parameter being expanded is a named reference, the
     reference itself is examined and thus is ‘not’ resolved to its
     referent.  In ksh emulation, the parens around this flag are
     optional.

‘#’

     Evaluate the resulting words as numeric expressions and interpret
     these as character codes.  Output the corresponding characters.
     Note that this form is entirely distinct from use of the ‘#’
     without parentheses.

     If the ‘MULTIBYTE’ option is set and the number is greater than 127
     (i.e.  not an ASCII character) it is treated as a Unicode
     character.

‘%’

     Expand all ‘%’ escapes in the resulting words in the same way as in
     prompts (see *note Expansion of Prompt Sequences: 6f.).  If this
     flag is given twice, full prompt expansion is done on the resulting
     words, depending on the setting of the ‘PROMPT_PERCENT’,
     ‘PROMPT_SUBST’ and ‘PROMPT_BANG’ options.

‘@’

     In double quotes, array elements are put into separate words.
     E.g., ‘"${(@)foo}"’ is equivalent to ‘"${foo[@]}"’ and
     ‘"${(@)foo[1,2]}"’ is the same as ‘"$foo[1]" "$foo[2]"’.  This is
     distinct from ‘field splitting’ by the ‘f’, ‘s’ or ‘z’ flags, which
     still applies within each array element.

‘A’

     Convert the substitution into an array expression, even if it
     otherwise would be scalar.  This has lower precedence than
     subscripting, so one level of nested expansion is required in order
     that subscripts apply to array elements.  Thus ‘${${(A)’NAME‘}[1]}’
     yields the full value of NAME when NAME is scalar.

     This assigns an array parameter with ‘${...=...}’, ‘${...:=...}’ or
     ‘${...::=...}’.  If this flag is repeated (as in ‘AA’), assigns an
     associative array parameter.  Assignment is made before sorting or
     padding; if field splitting is active, the WORD part is split
     before assignment.  The NAME part may be a subscripted range for
     ordinary arrays; when assigning an associative array, the WORD part
     ‘must’ be converted to an array, for example by using
     ‘${(AA)=’NAME‘=...}’ to activate field splitting.

     Surrounding context such as additional nesting or use of the value
     in a scalar assignment may cause the array to be joined back into a
     single string again.

‘a’

     Sort in array index order; when combined with ‘O’ sort in reverse
     array index order.  Note that ‘a’ is therefore equivalent to the
     default but ‘Oa’ is useful for obtaining an array’s elements in
     reverse order.

‘b’

     Quote with backslashes only characters that are special to pattern
     matching.  This is useful when the contents of the variable are to
     be tested using ‘GLOB_SUBST’, including the ‘${~’…‘}’ switch.

     Quoting using one of the ‘q’ family of flags does not work for this
     purpose since quotes are not stripped from non-pattern characters
     by ‘GLOB_SUBST’.  In other words,

           pattern=${(q)str}
           [[ $str = ${~pattern} ]]

     works if ‘$str’ is ‘a*b’ but not if it is ‘a b’, whereas

           pattern=${(b)str}
           [[ $str = ${~pattern} ]]

     is always true for any possible value of ‘$str’.

‘c’

     With ‘${#’NAME‘}’, count the total number of characters in an
     array, as if the elements were concatenated with spaces between
     them.  This is not a true join of the array, so other expressions
     used with this flag may have an effect on the elements of the array
     before it is counted.

‘C’

     Capitalize the resulting words.  ‘Words’ in this case refers to
     sequences of alphanumeric characters separated by
     non-alphanumerics, ‘not’ to words that result from field splitting.

‘D’

     Assume the string or array elements contain directories and attempt
     to substitute the leading part of these by names.  The remainder of
     the path (the whole of it if the leading part was not substituted)
     is then quoted so that the whole string can be used as a shell
     argument.  This is the reverse of ‘~’ substitution: see *note
     Filename Expansion: 5d.

‘e’

     Perform single word shell expansions, namely ‘parameter expansion’,
     ‘command substitution’ and ‘arithmetic expansion’, on the result.
     Such expansions can be nested but too deep recursion may have
     unpredictable effects.

‘f’

     Split the result of the expansion at newlines.  This is a shorthand
     for ‘ps:\n:’.

‘F’

     Join the words of arrays together using newline as a separator.
     This is a shorthand for ‘pj:\n:’.

‘g:’OPTS‘:’

     Process escape sequences like the echo builtin when no options are
     given (‘g::’).  With the ‘o’ option, octal escapes don’t take a
     leading zero.  With the ‘c’ option, sequences like ‘^X’ are also
     processed.  With the ‘e’ option, processes ‘\M-t’ and similar
     sequences like the print builtin.  With both of the ‘o’ and ‘e’
     options, behaves like the print builtin except that in none of
     these modes is ‘\c’ interpreted.

‘i’

     Sort case-insensitively.  May be combined with ‘n’ or ‘O’.

‘k’

     If NAME refers to an associative array, substitute the ‘keys’
     (element names) rather than the values of the elements.  Used with
     subscripts (including ordinary arrays), force indices or keys to be
     substituted even if the subscript form refers to values.  However,
     this flag may not be combined with subscript ranges.  With the
     ‘KSH_ARRAYS’ option a subscript ‘[*]’ or ‘[@]’ is needed to operate
     on the whole array, as usual.

‘L’

     Convert all letters in the result to lower case, like ‘typeset -l’.

‘n’

     Sort decimal integers numerically; if the first differing
     characters of two test strings are not digits, sorting is lexical.
     ‘+’ and ‘-’ are not treated specially; they are treated as any
     other non-digit.  Integers with more initial zeroes are sorted
     before those with fewer or none.  Hence the array ‘foo+24 foo1
     foo02 foo2 foo3 foo20 foo23’ is sorted into the order shown.  May
     be combined with ‘i’ or ‘O’.

‘-’

     As ‘n’, but a leading minus sign indicates a negative decimal
     integer.  A leading minus sign not followed by an integer does not
     trigger numeric sorting.  Note that ‘+’ signs are not handled
     specially (this may change in the future).

‘o’

     Sort the resulting words in ascending order; if this appears on its
     own the sorting is lexical and case-sensitive (unless the locale
     renders it case-insensitive).  Sorting in ascending order is the
     default for other forms of sorting, so this is ignored if combined
     with ‘a’, ‘i’, ‘n’ or ‘-’.

‘O’

     Sort the resulting words in descending order; ‘O’ without ‘a’, ‘i’,
     ‘n’ or ‘-’ sorts in reverse lexical order.  May be combined with
     ‘a’, ‘i’, ‘n’ or ‘-’ to reverse the order of sorting.

‘P’

     This forces the value of the parameter NAME to be interpreted as a
     further parameter name, whose value will be used where appropriate.
     Note that flags set with one of the ‘typeset’ family of commands
     (in particular case transformations) are not applied to the value
     of NAME used in this fashion.

     If used with a nested parameter or command substitution, the result
     of that will be taken as a parameter name in the same way.  For
     example, if you have ‘foo=bar’ and ‘bar=baz’, the strings
     ‘${(P)foo}’, ‘${(P)${foo}}’, and ‘${(P)$(echo bar)}’ will be
     expanded to ‘baz’.

     Likewise, if the reference is itself nested, the expression with
     the flag is treated as if it were directly replaced by the
     parameter name.  It is an error if this nested substitution
     produces an array with more than one word.  For example, if
     ‘name=assoc’ where the parameter ‘assoc’ is an associative array,
     then ‘${${(P)name}[elt]}’ refers to the element of the associative
     subscripted ‘elt’.

‘q’

     Quote characters that are special to the shell in the resulting
     words with backslashes; unprintable or invalid characters are
     quoted using the ‘$'\’NNN‘'’ form, with separate quotes for each
     octet.

     If this flag is given twice, the resulting words are quoted in
     single quotes and if it is given three times, the words are quoted
     in double quotes; in these forms no special handling of unprintable
     or invalid characters is attempted.  If the flag is given four
     times, the words are quoted in single quotes preceded by a ‘$’.
     Note that in all three of these forms quoting is done
     unconditionally, even if this does not change the way the resulting
     string would be interpreted by the shell.

     If a ‘q-’ is given (only a single ‘q’ may appear), a minimal form
     of single quoting is used that only quotes the string if needed to
     protect special characters.  Typically this form gives the most
     readable output.

     If a ‘q+’ is given, an extended form of minimal quoting is used
     that causes unprintable characters to be rendered using ‘$'’…‘'’.
     This quoting is similar to that used by the output of values by the
     ‘typeset’ family of commands.

‘Q’

     Remove one level of quotes from the resulting words.

‘t’

     Use a string describing the type of the parameter where the value
     of the parameter would usually appear.  This string consists of
     keywords separated by hyphens (‘-’).  The first keyword in the
     string describes the main type, it can be one of ‘scalar’, ‘array’,
     ‘integer’, ‘float’ or ‘association’.  The other keywords describe
     the type in more detail, in most cases corresponding to options of
     the ‘typeset’ command:

     ‘local’

          for local parameters

     ‘left’

          for left justified parameters (‘-L’)

     ‘right_blanks’

          for right justified parameters with leading blanks (‘-R’)

     ‘right_zeros’

          for right justified parameters with leading zeros (‘-Z’)

     ‘lower’

          for parameters whose value is converted to all lower case when
          it is expanded (‘-l’)

     ‘upper’

          for parameters whose value is converted to all upper case when
          it is expanded (‘-u’)

     ‘readonly’

          for readonly parameters (‘-r’)

     ‘tag’

          for tagged parameters (‘-t’)

     ‘tied’

          for parameters tied to another parameter in the manner of
          ‘PATH’ (colon-separated list) and ‘path’ (array), whether
          these are special parameters or user-defined with ‘typeset -T’

     ‘export’

          for exported parameters (‘-x’ or ‘export’)

     ‘unique’

          for arrays which keep only the first occurrence of duplicated
          values (‘-U’)

     ‘hide’

          for parameters with the ‘hide’ flag (‘-h’)

     ‘hideval’

          for parameters with the ‘hideval’ flag (‘-H’)

     ‘nameref’

          for named references (‘typeset -n’) either having an empty
          value or when combined with ‘!’ as in ‘${(!t):var:`rname`}’

     ‘special’

          for special parameters defined by the shell

‘u’

     Expand only the first occurrence of each unique word, like ‘typeset
     -U’.

‘U’

     Convert all letters in the result to upper case, like ‘typeset -u’.

‘v’

     Used with ‘k’, substitute (as two consecutive words) both the key
     and the value of each associative array element.  Used with
     subscripts, force values to be substituted even if the subscript
     form refers to indices or keys.

‘V’

     Make any special characters in the resulting words visible.

‘w’

     With ‘${#’NAME‘}’, count words in arrays or strings; the ‘s’ flag
     may be used to set a word delimiter.

‘W’

     Similar to ‘w’ with the difference that empty words between
     repeated delimiters are also counted.

‘X’

     With this flag, parsing errors occurring with the ‘Q’, ‘e’ and ‘#’
     flags or the pattern matching forms such as ‘${’NAME‘#’PATTERN‘}’
     are reported.  Without the flag, errors are silently ignored.

‘z’

     Split the result of the expansion into words using shell parsing to
     find the words, i.e.  taking into account any quoting in the value.
     Comments are not treated specially but as ordinary strings, similar
     to interactive shells with the ‘INTERACTIVE_COMMENTS’ option unset
     (however, see the ‘Z’ flag below for related options)

     Note that this is done very late, even later than the ‘(s)’ flag.
     So to access single words in the result use nested expansions as in
     ‘${${(z)foo}[2]}’.  Likewise, to remove the quotes in the resulting
     words use ‘${(Q)${(z)foo}}’.

‘0’

     Split the result of the expansion on null bytes.  This is a
     shorthand for ‘ps:\0:’.

The following flags (except ‘p’) are followed by one or more arguments
as shown.  Any character, or the matching pairs ‘(...)’, ‘{...}’,
‘[...]’, or ‘<...>’, may be used in place of a colon as delimiters, but
note that when a flag takes more than one argument, a matched pair of
delimiters must surround each argument.

‘p’

     Recognize the same escape sequences as the ‘print’ builtin in
     string arguments to any of the flags described below that follow
     this argument.

     Alternatively, with this option string arguments may be in the form
     ‘$’VAR in which case the value of the variable is substituted.
     Note this form is strict; the string argument does not undergo
     general parameter expansion.

     For example,

           sep=:
           val=a:b:c
           print ${(ps.$sep.)val}

     splits the variable on a ‘:’.

‘~’

     Strings inserted into the expansion by any of the flags below are
     to be treated as patterns.  This applies to the string arguments of
     flags that follow ‘~’ within the same set of parentheses.  Compare
     with ‘~’ outside parentheses, which forces the entire substituted
     string to be treated as a pattern.  Hence, for example,

           [[ "?" = ${(~j.|.)array} ]]

     treats ‘|’ as a pattern and succeeds if and only if ‘$array’
     contains the string ‘?’ as an element.  The ‘~’ may be repeated to
     toggle the behaviour; its effect only lasts to the end of the
     parenthesised group.

‘j:’STRING‘:’

     Join the words of arrays together using STRING as a separator.  ..
     index:: single: SH_WORD_SPLIT, use of; Program

     Note that this occurs before field splitting by the ‘s:’STRING‘:’
     flag or the ‘SH_WORD_SPLIT’ option.

‘l:’EXPR‘::’STRING1‘::’STRING2‘:’

     Pad the resulting words on the left.  Each word will be truncated
     if required and placed in a field EXPR characters wide.

     The arguments ‘:’STRING1‘:’ and ‘:’STRING2‘:’ are optional;
     neither, the first, or both may be given.  Note that the same pairs
     of delimiters must be used for each of the three arguments.  The
     space to the left will be filled with STRING1 (concatenated as
     often as needed) or spaces if STRING1 is not given.  If both
     STRING1 and STRING2 are given, STRING2 is inserted once directly to
     the left of each word, truncated if necessary, before STRING1 is
     used to produce any remaining padding.

     If either of STRING1 or STRING2 is present but empty, i.e.  there
     are two delimiters together at that point, the first character of
     ‘$IFS’ is used instead.

     If the ‘MULTIBYTE’ option is in effect, the flag ‘m’ may also be
     given, in which case widths will be used for the calculation of
     padding; otherwise individual multibyte characters are treated as
     occupying one unit of width.

     If the ‘MULTIBYTE’ option is not in effect, each byte in the string
     is treated as occupying one unit of width.

     Control characters are always assumed to be one unit wide; this
     allows the mechanism to be used for generating repetitions of
     control characters.

‘m’

     Only useful together with one of the flags ‘l’ or ‘r’ or with the
     ‘#’ length operator when the ‘MULTIBYTE’ option is in effect.  Use
     the character width reported by the system in calculating how much
     of the string it occupies or the overall length of the string.
     Most printable characters have a width of one unit, however certain
     Asian character sets and certain special effects use wider
     characters; combining characters have zero width.  Non-printable
     characters are arbitrarily counted as zero width; how they would
     actually be displayed will vary.

     If the ‘m’ is repeated, the character either counts zero (if it has
     zero width), else one.  For printable character strings this has
     the effect of counting the number of glyphs (visibly separate
     characters), except for the case where combining characters
     themselves have non-zero width (true in certain alphabets).

‘r:’EXPR‘::’STRING1‘::’STRING2‘:’

     As ‘l’, but pad the words on the right and insert STRING2
     immediately to the right of the string to be padded.

     Left and right padding may be used together.  In this case the
     strategy is to apply left padding to the first half width of each
     of the resulting words, and right padding to the second half.  If
     the string to be padded has odd width the extra padding is applied
     on the left.

‘s:’STRING‘:’

     Force field splitting at the separator STRING.  Note that a STRING
     of two or more characters means that all of them must match in
     sequence; this differs from the treatment of two or more characters
     in the ‘IFS’ parameter.  See also the ‘=’ flag and the
     ‘SH_WORD_SPLIT’ option.  An empty string may also be given in which
     case every character will be a separate element.

     For historical reasons, the usual behaviour that empty array
     elements are retained inside double quotes is disabled for arrays
     generated by splitting; hence the following:

           line="one::three"
           print -l "${(s.:.)line}"

     produces two lines of output for ‘one’ and ‘three’ and elides the
     empty field.  To override this behaviour, supply the ‘(@)’ flag as
     well, i.e.  ‘"${(@s.:.)line}"’.

‘Z:’OPTS‘:’

     As ‘z’ but takes a combination of option letters between a
     following pair of delimiter characters.  With no options the effect
     is identical to ‘z’.  The following options are available:

     ‘(Z+c+)’

          causes comments to be parsed as a string and retained; any
          field in the resulting array beginning with an unquoted
          comment character is a comment.

     ‘(Z+C+)’

          causes comments to be parsed and removed.  The rule for
          comments is standard: anything between a word starting with
          the third character of ‘$HISTCHARS’, default ‘#’, up to the
          next newline is a comment.

     ‘(Z+n+)’

          causes unquoted newlines to be treated as ordinary whitespace,
          else they are treated as if they are shell code delimiters and
          converted to semicolons.

     Options are combined within the same set of delimiters, e.g.
     ‘(Z+Cn+)’.

‘_:’FLAGS‘:’

     The underscore (‘_’) flag is reserved for future use.  As of this
     revision of zsh, there are no valid FLAGS; anything following an
     underscore, other than an empty pair of delimiters, is treated as
     an error, and the flag itself has no effect.

The following flags are meaningful with the ‘${...#...}’ or ‘${...%...}’
forms.  The ‘S’, ‘I’, and ‘*’ flags may also be used with the
‘${.../...}’ forms.

‘S’

     With ‘#’ or ‘##’, search for the match that starts closest to the
     start of the string (a ‘substring match’).  Of all matches at a
     particular position, ‘#’ selects the shortest and ‘##’ the longest:

           % str="aXbXc"
           % echo ${(S)str#X*}
           abXc
           % echo ${(S)str##X*}
           a
           %

     With ‘%’ or ‘%%’, search for the match that starts closest to the
     end of the string:

           % str="aXbXc"
           % echo ${(S)str%X*}
           aXbc
           % echo ${(S)str%%X*}
           aXb
           %

     (Note that ‘%’ and ‘%%’ don’t search for the match that ends
     closest to the end of the string, as one might expect.)

     With substitution via ‘${.../...}’ or ‘${...//...}’, specifies
     non-greedy matching, i.e.  that the shortest instead of the longest
     match should be replaced:

           % str="abab"
           % echo ${str/*b/_}
           _
           % echo ${(S)str/*b/_}
           _ab
           %

‘I:’EXPR‘:’

     Search the EXPRth match (where EXPR evaluates to a number).  This
     only applies when searching for substrings, either with the ‘S’
     flag, or with ‘${.../...}’ (only the EXPRth match is substituted)
     or ‘${...//...}’ (all matches from the EXPRth on are substituted).
     The default is to take the first match.

     The EXPRth match is counted such that there is either one or zero
     matches from each starting position in the string, although for
     global substitution matches overlapping previous replacements are
     ignored.  With the ‘${...%...}’ and ‘${...%%...}’ forms, the
     starting position for the match moves backwards from the end as the
     index increases, while with the other forms it moves forward from
     the start.

     Hence with the string

           which switch is the right switch for Ipswich?

     substitutions of the form ‘${(SI:’N‘:)string#w*ch}’ as N increases
     from 1 will match and remove ‘which’, ‘witch’, ‘witch’ and ‘wich’;
     the form using ‘##’ will match and remove ‘which switch is the
     right switch for Ipswich’,‘‘ witch is the right switch for
     Ipswich‘‘,‘‘ witch for Ipswich ‘and’ wich‘‘.  The form using‘‘ %‘‘
     will remove the same matches as for ‘#’, but in reverse order, and
     the form using ‘%%’ will remove the same matches as for ‘##’ in
     reverse order.

‘*’

     Enable ‘EXTENDED_GLOB’ for substitution via ‘${.../...}’ or
     ‘${...//...}’.  Note that ‘**’ does not disable extendedglob.

‘B’

     Include the index of the beginning of the match in the result.

‘E’

     Include the index one character past the end of the match in the
     result (note this is inconsistent with other uses of parameter
     index).

‘M’

     Include the matched portion in the result.

‘N’

     Include the length of the match in the result.

‘R’

     Include the unmatched portion in the result (the ‘R’est).


File: zsh.info,  Node: Named References,  Next: Rules,  Prev: Parameter Expansion Flags,  Up: Parameter Expansion

13.4.2 Named References
-----------------------

The command

     ‘typeset -n’ PNAME‘=’RNAME

initializes a parameter PNAME as a reference to a second parameter
RNAME.  The RNAME may also be omitted, in which case PNAME is a
placeholder which, the first time it is assigned, is initialized to an
active reference to the assigned RNAME.  See *note Named References: 71.
..  only:: not man

     under Parameters

for more about placeholders.

With the few exceptions described here, when PNAME is used in any of the
expansion forms described above, the parameter RNAME is expanded
instead.  This is similar to the action of the ‘(P)’ expansion flag, but
when RNAME has itself been declared a named reference, that third
parameter referenced by PNAME is also expanded, and so on.  With ‘(P)’
this must be done explicitly, so for example ‘${(P)${(P)’NAME‘}}’.

Unlike ‘(P)’, named references in substitutions that perform assignment,
such as ‘${’PNAME‘::=’WORD‘}’, do not create new arrays when RNAME is in
the form of an array element or slice and no such array (or associative
array) is presently set.  This includes arrays declared, but not
initialized, when the option ‘TYPESET_TO_UNSET’ is in effect.  The WORD
is substituted but no assignment occurs.

Also unlike ‘(P)’ named references always expand parameters at the scope
in which RNAME exists when PNAME is initialized.  This can be used to
expand or assign parameters from an earlier scope even if a local of the
same name has been declared at a later scope.  Example:

      caller=OUTER
      func () {
        print before local: $caller
        typeset -n outer=$1
        local caller=INNER
        print by reference: $outer
        outer=RESULT
      }
      func caller
      print after func: $caller

displays the output

      before local: OUTER
      by reference: OUTER
      after func: RESULT

To force a named reference to refer to the outer scope, even if a local
has already been declared, add the ‘-u’ option when declaring the named
reference.  In this case RNAME should already exist in the outer scope
before PNAME is initialized, otherwise the behavior of assignment
through PNAME is not defined and may change the scope of the reference
or fail with a status of 1.  Example of correct usage:

      caller=OUTER
      func () {
        print before local: $caller
        local caller=INNER
        print after local: $caller
        typeset -n -u outer=$1
        print by reference: $outer
        outer=RESULT
      }
      func caller
      print after func: $caller

Note, however, that named references to ‘special’ parameters acquire the
behavior of the special parameter, regardless of the scope where the
reference is declared.

In the event that the local PNAME goes out of scope (its declaring
function returns) before the reference RNAME goes out of scope, the
reference may change to another parameter having the same name as PNAME,
or assignments may fail as described above.  Keep the declaration of
RNAME as close as possible to its initialization to PNAME to avoid
confusion.

When RNAME includes an array subscript, the subscript expression is
interpreted at the time ‘${’PNAME‘}’ is expanded.  Any form of subscript
is allowed, including those that select individual elements, substrings
of scalar strings, or multiple elements as with array slices or the
‘(i)’, ‘(I)’, ‘(r)’, ‘(R)’ and ‘(w)’ subscript flags.  However, the
subscript is evaluated with the ‘NO_EXEC’ option in effect, so command
substitution and other similar constructs produce no output, although
are not syntactically excluded.

When RNAME is an array (but not an array element or slice), the named
reference may also be used in substitutions requiring an ARRAYNAME, so
these are equivalent:

      ${NAME:|RNAME}
      ${NAME:|PNAME}

Expansions of the form ‘${(t)’PNAME‘}’ expand the type information of
RNAME, unless RNAME is empty, in which case the expansion is ‘nameref’,
or when no variable RNAME exists, in which case the expansion is empty.

See also ‘zshparam’.


File: zsh.info,  Node: Rules,  Next: Examples,  Prev: Named References,  Up: Parameter Expansion

13.4.3 Rules
------------

Here is a summary of the rules for substitution; this assumes that
braces are present around the substitution, i.e.  ‘${’…‘}’.  Some
particular examples are given below.  Note that the Zsh Development
Group accepts ‘no responsibility’ for any brain damage which may occur
during the reading of the following rules.

‘1.’ ‘Nested substitution’

     If multiple nested ‘${’…‘}’ forms are present, substitution is
     performed from the inside outwards.  At each level, the
     substitution takes account of whether the current value is a scalar
     or an array, whether the whole substitution is in double quotes,
     and what flags are supplied to the current level of substitution,
     just as if the nested substitution were the outermost.  The flags
     are not propagated up to enclosing substitutions; the nested
     substitution will return either a scalar or an array as determined
     by the flags, possibly adjusted for quoting.  All the following
     steps take place where applicable at all levels of substitution.

     Note that, unless the ‘(P)’ flag or a named reference is present,
     the flags and any subscripts apply directly to the value of the
     nested substitution; for example, the expansion ‘${${foo}}’ behaves
     exactly the same as ‘${foo}’.  When a named reference or the ‘(P)’
     flag is used in a nested substitution, the other substitution rules
     are applied to the value ‘before’ it is interpreted as a name, so
     ‘${${(P)foo}}’ may differ from ‘${(P)foo}’.  When both a named
     reference and the ‘(P)’ flag appear, the named reference is
     resolved before ‘(P)’ is applied.

     At each nested level of substitution, the substituted words undergo
     all forms of single-word substitution (i.e.  not filename
     generation), including command substitution, arithmetic expansion
     and filename expansion (i.e.  leading ‘~’ and ‘=’).  Thus, for
     example, ‘${${:-=cat}:h}’ expands to the directory where the ‘cat’
     program resides.  (Explanation: the internal substitution has no
     parameter but a default value ‘=cat’, which is expanded by filename
     expansion to a full path; the outer substitution then applies the
     modifier ‘:h’ and takes the directory part of the path.)

‘2.’ ‘Internal parameter flags’

     Any parameter flags set by one of the ‘typeset’ family of commands,
     in particular the ‘-L’, ‘-R’, ‘-Z’, ‘-u’ and ‘-l’ options for
     padding and capitalization, are applied directly to the parameter
     value.  Note these flags are options to the command, e.g.  ‘typeset
     -Z’; they are not the same as the flags used within parameter
     substitutions.

     At the outermost level of substitution, the ‘(P)’ flag (rule ‘4.’)
     ignores these transformations and uses the unmodified value of the
     parameter as the name to be replaced.  This is usually the desired
     behavior because padding may make the value syntactically invalid
     as a parameter name, but if capitalization changes are desired, use
     the ‘${${(P)foo}}’ form (rule ‘25.’).

‘3.’ ‘Parameter subscripting’

     If the value is a raw parameter reference with a subscript, such as
     ‘${’VAR‘[3]}’, the effect of subscripting is applied directly to
     the parameter.  Subscripts are evaluated left to right; subsequent
     subscripts apply to the scalar or array value yielded by the
     previous subscript.  Thus if ‘var’ is an array, ‘${var[1][2]}’ is
     the second character of the first word, but ‘${var[2,4][2]}’ is the
     entire third word (the second word of the range of words two
     through four of the original array).  Any number of subscripts may
     appear.  Flags such as ‘(k)’ and ‘(v)’ which alter the result of
     subscripting are applied.

‘4.’ ‘Parameter name replacement’

     At the outermost level of nesting only, the ‘(P)’ flag is applied.
     This treats the value so far as a parameter name (which may include
     a subscript expression) and replaces that with the corresponding
     value.  This replacement occurs later if the ‘(P)’ flag appears in
     a nested substitution.

     If the value so far names a parameter that has internal flags (rule
     ‘2.’), those internal flags are applied to the new value after
     replacement.

‘5.’ ‘Double-quoted joining’

     If the value after this process is an array, and the substitution
     appears in double quotes, and neither an ‘(@)’ flag nor a ‘#’
     length operator is present at the current level, then words of the
     value are joined with the first character of the parameter ‘$IFS’,
     by default a space, between each word (single word arrays are not
     modified).  If the ‘(j)’ flag is present, that is used for joining
     instead of ‘$IFS’.

‘6.’ ‘Nested subscripting’

     Any remaining subscripts (i.e.  of a nested substitution) are
     evaluated at this point, based on whether the value is an array or
     a scalar.  As with ‘3.’, multiple subscripts can appear.  Note that
     ‘${foo[2,4][2]}’ is thus equivalent to ‘${${foo[2,4]}[2]}’ and also
     to ‘"${${(@)foo[2,4]}[2]}"’ (the nested substitution returns an
     array in both cases), but not to ‘"${${foo[2,4]}[2]}"’ (the nested
     substitution returns a scalar because of the quotes).

‘7.’ ‘Modifiers’

     Any modifiers, as specified by a trailing ‘#’, ‘%’, ‘/’ (possibly
     doubled) or by a set of modifiers of the form ‘:...’ (see *note
     Modifiers: 6b. in *note History Expansion: 66.), are applied to the
     words of the value at this level.

‘8.’ ‘Character evaluation’

     Any ‘(#)’ flag is applied, evaluating the result so far numerically
     as a character.

‘9.’ ‘Length’

     Any initial ‘#’ modifier, i.e.  in the form ‘${#’VAR‘}’, is used to
     evaluate the length of the expression so far.

‘10.’ ‘Forced joining’

     If the ‘(j)’ flag is present, or no ‘(j)’ flag is present but the
     string is to be split as given by rule ‘11.’, and joining did not
     take place at rule ‘5.’, any words in the value are joined together
     using the given string or the first character of ‘$IFS’ if none.
     Note that the ‘(F)’ flag implicitly supplies a string for joining
     in this manner.

‘11.’ ‘Simple word splitting’

     If one of the ‘(s)’ or ‘(f)’ flags are present, or the ‘=’
     specifier was present (e.g.  ‘${=’VAR‘}’), the word is split on
     occurrences of the specified string, or (for ‘=’ with neither of
     the two flags present) any of the characters in ‘$IFS’.

     If no ‘(s)’, ‘(f)’ or ‘=’ was given, but the word is not quoted and
     the option ‘SH_WORD_SPLIT’ is set, the word is split on occurrences
     of any of the characters in ‘$IFS’.  Note this step, too, takes
     place at all levels of a nested substitution.

‘12.’ ‘Case modification’

     Any case modification from one of the flags ‘(L)’, ‘(U)’ or ‘(C)’
     is applied.

‘13.’ ‘Escape sequence replacement’

     First any replacements from the ‘(g)’ flag are performed, then any
     prompt-style formatting from the ‘(%)’ family of flags is applied.

‘14.’ ‘Quote application’

     Any quoting or unquoting using ‘(q)’ and ‘(Q)’ and related flags is
     applied.

‘15.’ ‘Directory naming’

     Any directory name substitution using ‘(D)’ flag is applied.

‘16.’ ‘Visibility enhancement’

     Any modifications to make characters visible using the ‘(V)’ flag
     are applied.

‘17.’ ‘Lexical word splitting’

     If the ‘‘(z)’’ flag or one of the forms of the ‘‘(Z)’’ flag is
     present, the word is split as if it were a shell command line, so
     that quotation marks and other metacharacters are used to decide
     what constitutes a word.  Note this form of splitting is entirely
     distinct from that described by rule ‘11.’: it does not use ‘$IFS’,
     and does not cause forced joining.

‘18.’ ‘Uniqueness’

     If the result is an array and the ‘(u)’ flag was present, duplicate
     elements are removed from the array.

‘19.’ ‘Ordering’

     If the result is still an array and one of the ‘(o)’ or ‘(O)’ flags
     was present, the array is reordered.

‘20.’  ‘RC_EXPAND_PARAM’

     At this point the decision is made whether any resulting array
     elements are to be combined element by element with surrounding
     text, as given by either the ‘RC_EXPAND_PARAM’ option or the ‘^’
     flag.

‘21.’ ‘Re-evaluation’

     Any ‘(e)’ flag is applied to the value, forcing it to be
     re-examined for new parameter substitutions, but also for command
     and arithmetic substitutions.

‘22.’ ‘Padding’

     Any padding of the value by the ‘(l.’FILL‘.)’ or ‘(r.’FILL‘.)’
     flags is applied.

‘23.’ ‘Semantic joining’

     In contexts where expansion semantics requires a single word to
     result, all words are rejoined with the first character of ‘IFS’
     between.  So in ‘${(P)${(f)lines}}’ the value of ‘${lines}’ is
     split at newlines, but then must be joined again before the ‘(P)’
     flag can be applied.

     If a single word is not required, this rule is skipped.

‘24.’ ‘Empty argument removal’

     If the substitution does not appear in double quotes, any resulting
     zero-length argument, whether from a scalar or an element of an
     array, is elided from the list of arguments inserted into the
     command line.

     Strictly speaking, the removal happens later as the same happens
     with other forms of substitution; the point to note here is simply
     that it occurs after any of the above parameter operations.

‘25.’ ‘Nested parameter name replacement’

     If the ‘(P)’ flag is present and rule ‘4.’ has not applied, the
     value so far is treated as a parameter name (which may include a
     subscript expression) and replaced with the corresponding value,
     with internal flags (rule ‘2.’) applied to the new value.


File: zsh.info,  Node: Examples,  Prev: Rules,  Up: Parameter Expansion

13.4.4 Examples
---------------

The flag ‘f’ is useful to split a double-quoted substitution line by
line.  For example, ‘${(f)"$(<’FILE‘)"}’ substitutes the contents of
FILE divided so that each line is an element of the resulting array.
Compare this with the effect of ‘$(<’FILE‘)’ alone, which divides the
file up by words, or the same inside double quotes, which makes the
entire content of the file a single string.

The following illustrates the rules for nested parameter expansions.
Suppose that ‘$foo’ contains the array ‘(bar baz)’:

‘"${(@)${foo}[1]}"’

     This produces the result ‘b’.  First, the inner substitution
     ‘"${foo}"’, which has no array (‘@’) flag, produces a single word
     result ‘"bar baz"’.  The outer substitution ‘"${(@)...[1]}"’
     detects that this is a scalar, so that (despite the ‘(@)’ flag) the
     subscript picks the first character.

‘"${${(@)foo}[1]}"’

     This produces the result ‘bar’.  In this case, the inner
     substitution ‘"${(@)foo}"’ produces the array ‘(bar baz)’.  The
     outer substitution ‘"${...[1]}"’ detects that this is an array and
     picks the first word.  This is similar to the simple case
     ‘"${foo[1]}"’.

As an example of the rules for word splitting and joining, suppose
‘$foo’ contains the array ‘(ax1 bx1)’.  Then

‘${(s/x/)foo}’

     produces the words ‘a’, ‘1 b’ and ‘1’.

‘${(j/x/s/x/)foo}’

     produces ‘a’, ‘1’, ‘b’ and ‘1’.

‘${(s/x/)foo%%1*}’

     produces ‘a’ and ‘b’ (note the extra space).  As substitution
     occurs before either joining or splitting, the operation first
     generates the modified array ‘(ax bx)’, which is joined to give
     ‘"ax bx"’, and then split to give ‘a’, ‘b’ and >>‘<<’.  The final
     empty string will then be elided, as it is not in double quotes.


File: zsh.info,  Node: Command Substitution,  Next: Arithmetic Expansion,  Prev: Parameter Expansion,  Up: Expansion

13.5 Command Substitution
=========================

A command enclosed in parentheses preceded by a dollar sign, like
‘$(...)’, or quoted with grave accents, like ‘...\`', is executed in a
subshell and replaced by its standard output, with any trailing newlines
deleted. If the substitution is not enclosed in double quotes, the
output is broken into words using the ``IFS’ parameter.  ..  index::
single: IFS, use of; Variable

The substitution ‘$(cat’ FOO‘)’ may be replaced by the faster $(<FOO‘)’.
In this case FOO undergoes single word shell expansions (‘parameter
expansion’, ‘command substitution’ and ‘arithmetic expansion’), but not
filename generation.  No subshell is created.

If the option ‘GLOB_SUBST’ is set, the result of any unquoted command
substitution, including the special form just mentioned, is eligible for
filename generation.

A command with a leading pipe character, enclosed in braces prefixed by
a dollar sign, as in ${>>|<<…}, is executed in the current shell
context, rather than in a subshell, and is replaced by the value of the
parameter ‘REPLY’ at the end of the command.  There ‘must not’ be any
whitespace between the opening brace and the pipe character.  Any prior
value of ‘$REPLY’ is saved and restored around this substitution, in the
manner of a function local parameter.  Other parameters declared within
the substitution also behave as locals, as if in a function, unless
‘typeset -g’ is used.  Trailing newlines are ‘not’ deleted from the
final replacement in this case, and it is subject to filename generation
in the same way as $(…) but is ‘not’ split on ‘IFS’ unless the
‘SH_WORD_SPLIT’ option is set.

Substitutions of the form ${{PARAM‘}’ …} are similar, except that the
substitution is replaced by the value of the parameter named by PARAM.
No implicit save or restore applies to PARAM and PARAM should ‘not’ be
declared within the command.  No space is allowed within ${{ and space
or newline is required after {PARAM‘}’.  The PARAM may include a
subscript, and if, after evaluating the expression, PARAM names an
array, then array expansion rules apply to the final substitution.

A command enclosed in braces preceded by a dollar sign, and set off from
the braces by whitespace, like ‘${’ … ‘}’, is replaced by its standard
output.  Like ${>>|<<…} and unlike $(…), the command executes in the
current shell context with function local behaviors and does not create
a subshell.  Word splitting does not apply unless ‘SH_WORD_SPLIT’ is
set, but a single trailing newline is stripped unless the substitution
is enclosed in double quotes.

Note that because ${>>|<<…} and the two related substitutions must be
parsed at once as both string tokens and commands, all other braces ({
or }) within the command either must be quoted, or must appear in
syntactically valid pairs, such as around complex commands, function
bodies, or parameter references.  Furthermore, comments are always
recognized, even when ‘NO_INTERACTIVE_COMMENTS’ is in effect.


File: zsh.info,  Node: Arithmetic Expansion,  Next: Brace Expansion,  Prev: Command Substitution,  Up: Expansion

13.6 Arithmetic Expansion
=========================

A string of the form $[EXP‘]’ or $((EXP‘))’ is substituted with the
value of the arithmetic expression EXP.  EXP is subjected to ‘parameter
expansion’, ‘command substitution’ and ‘arithmetic expansion’ before it
is evaluated.  See *note Arithmetic Evaluation: 76.


File: zsh.info,  Node: Brace Expansion,  Next: Filename Expansion,  Prev: Arithmetic Expansion,  Up: Expansion

13.7 Brace Expansion
====================

A string of the form FOO‘{’XX‘,’YY‘,’ZZ‘}’BAR is expanded to the
individual words FOOXXBAR, FOOYYBAR and FOOZZBAR.  Left-to-right order
is preserved.  This construct may be nested.  Commas may be quoted in
order to include them literally in a word.

An expression of the form {N1‘..’N2‘}’, where N1 and N2 are integers, is
expanded to every number between N1 and N2 inclusive.  If either number
begins with a zero, all the resulting numbers will be padded with
leading zeroes to that minimum width, but for negative numbers the -
character is also included in the width.  If the numbers are in
decreasing order the resulting sequence will also be in decreasing
order.

An expression of the form {N1‘..’N2‘..’N3‘}’, where N1, N2, and N3 are
integers, is expanded as above, but only every N3th number starting from
N1 is output.  If N3 is negative the numbers are output in reverse
order, this is slightly different from simply swapping N1 and N2 in the
case that the step N3 doesn’t evenly divide the range.  Zero padding can
be specified in any of the three numbers, specifying it in the third can
be useful to pad for example ‘{-99..100..01}’ which is not possible to
specify by putting a 0 on either of the first two numbers (i.e.  pad to
two characters).

An expression of the form {C1‘..’C2‘}’, where C1 and C2 are single
characters (which may be multibyte characters), is expanded to every
character in the range from C1 to C2 in whatever character sequence is
used internally.  For characters with code points below 128 this is US
ASCII (this is the only case most users will need).  If any intervening
character is not printable, appropriate quotation is used to render it
printable.  If the character sequence is reversed, the output is in
reverse order, e.g.  ‘{d..a}’ is substituted as ‘d c b a’.

If a brace expression matches none of the above forms, it is left
unchanged, unless the option ‘BRACE_CCL’ (an abbreviation for ‘brace
character class’) is set.  ..  index:: single: BRACE_CCL, use of;
Program

In that case, it is expanded to a list of the individual characters
between the braces sorted into the order of the characters in the ASCII
character set (multibyte characters are not currently handled).  The
syntax is similar to a […] expression in filename generation: - is
treated specially to denote a range of characters, but ^ or !  as the
first character is treated normally.  For example, ‘{abcdef0-9}’ expands
to 16 words ‘0 1 2 3 4 5 6 7 8 9 a b c d e f’.

Note that brace expansion is not part of filename generation (globbing);
an expression such as ‘*/{foo,bar}’ is split into two separate words
‘*/foo’ and ‘*/bar’ before filename generation takes place.  In
particular, note that this is liable to produce a ‘no match’ error if
‘either’ of the two expressions does not match; this is to be contrasted
with ‘*/(foo|bar)’, which is treated as a single pattern but otherwise
has similar effects.

To combine brace expansion with array expansion, see the
${^:var:‘spec’‘}’ form described in *note Parameter Expansion: 1a.
above.


File: zsh.info,  Node: Filename Expansion,  Next: Filename Generation,  Prev: Brace Expansion,  Up: Expansion

13.8 Filename Expansion
=======================

Each word is checked to see if it begins with an unquoted ~.  If it
does, then the word up to a /, or the end of the word if there is no /,
is checked to see if it can be substituted in one of the ways described
here.  If so, then the ~ and the checked portion are replaced with the
appropriate substitute value.

A ~ by itself is replaced by the value of ‘$HOME’.  A ~ followed by a +
or a - is replaced by current or previous working directory,
respectively.

A ~ followed by a number is replaced by the directory at that position
in the directory stack.  ‘~0’ is equivalent to ~+, and ‘~1’ is the top
of the stack.  ~+ followed by a number is replaced by the directory at
that position in the directory stack.  ‘~+0’ is equivalent to ~+, and
‘~+1’ is the top of the stack.  ~- followed by a number is replaced by
the directory that many positions from the bottom of the stack.  ‘~-0’
is the bottom of the stack.  ..  index:: single: PUSHD_MINUS, use of;
Program

The ‘PUSHD_MINUS’ option exchanges the effects of ~+ and ~- where they
are followed by a number.

* Menu:

* Dynamic Named Directories::
* Static Named Directories::
* `=’ Expansion::
* Notes::


File: zsh.info,  Node: Dynamic Named Directories,  Next: Static Named Directories,  Up: Filename Expansion

13.8.1 Dynamic Named Directories
--------------------------------

If the function ‘zsh_directory_name’ exists, or the shell variable
‘zsh_directory_name_functions’ exists and contains an array of function
names, then the functions are used to implement dynamic directory
naming.  The functions are tried in order until one returns status zero,
so it is important that functions test whether they can handle the case
in question and return an appropriate status.

A ~ followed by a string NAMSTR in unquoted square brackets is treated
specially as a dynamic directory name.  Note that the first unquoted
closing square bracket always terminates NAMSTR.  The shell function is
passed two arguments: the string ‘n’ (for name) and NAMSTR.  It should
either set the array ‘reply’ to a single element which is the directory
corresponding to the name and return status zero (executing an
assignment as the last statement is usually sufficient), or it should
return status non-zero.  In the former case the element of reply is used
as the directory; in the latter case the substitution is deemed to have
failed.  If all functions fail and the option ‘NOMATCH’ is set, an error
results.

The functions defined as above are also used to see if a directory can
be turned into a name, for example when printing the directory stack or
when expanding %~ in prompts.  In this case each function is passed two
arguments: the string ‘d’ (for directory) and the candidate for dynamic
naming.  The function should either return non-zero status, if the
directory cannot be named by the function, or it should set the array
reply to consist of two elements: the first is the dynamic name for the
directory (as would appear within ~[…‘]’), and the second is the prefix
length of the directory to be replaced.  For example, if the trial
directory is ‘/home/myname/src/zsh’ and the dynamic name for
‘/home/myname/src’ (which has 16 characters) is ‘s’, then the function
sets

      reply=(s 16)

The directory name so returned is compared with possible static names
for parts of the directory path, as described below; it is used if the
prefix length matched (16 in the example) is longer than that matched by
any static name.

It is not a requirement that a function implements both ‘n’ and ‘d’
calls; for example, it might be appropriate for certain dynamic forms of
expansion not to be contracted to names.  In that case any call with the
first argument ‘d’ should cause a non-zero status to be returned.

The completion system calls ‘zsh_directory_name c’ followed by
equivalent calls to elements of the array
‘zsh_directory_name_functions’, if it exists, in order to complete
dynamic names for directories.  The code for this should be as for any
other completion function as described in ‘zsycompsys’.

As a working example, here is a function that expands any dynamic names
beginning with the string ‘p:’ to directories below
‘/home/pws/perforce’.  In this simple case a static name for the
directory would be just as effective.

      zsh_directory_name() {
        emulate -L zsh -o extendedglob
        local -a match mbegin mend
        local base=/home/pws/perforce
        case $1 in
        ( d )  # Turn the directory into a name.
          [[ $2 == (#b)($base/)([^/]##)* ]] &&
              reply=( p:$match[2] $(( $#match[1] + $#match[2] )) )
        ;;
        ( n )  # Turn the name into a directory.
          [[ $2 == (#b)p:(?*) ]] &&
              reply=( $base/$match[1] )
        ;;
        ( c )  # Complete names.
          local -a dirs=( $base/*(/:t) )
          # Completion system populates $expl with flags for compadd.
          compadd "$expl[@]" p:$^dirs
        ;;
        esac
      }


File: zsh.info,  Node: Static Named Directories,  Next: `=’ Expansion,  Prev: Dynamic Named Directories,  Up: Filename Expansion

13.8.2 Static Named Directories
-------------------------------

A ~ followed by anything not already covered consisting of any number of
alphanumeric characters or underscore (‘_’), hyphen (-), or dot (.)  is
looked up as a named directory, and replaced by the value of that named
directory if found.  Named directories are typically home directories
for users on the system.  They may also be defined if the text after the
~ is the name of a string shell parameter whose value begins with a /.
Note that trailing slashes will be removed from the path to the
directory (though the original parameter is not modified).

It is also possible to define directory names using the ‘-d’ option to
the ‘hash’ builtin.

When the shell prints a path (e.g.  when expanding %~ in prompts or when
printing the directory stack), the path is checked to see if it has a
named directory as its prefix.  If so, then the prefix portion is
replaced with a ~ followed by the name of the directory.  The shorter of
the two ways of referring to the directory is used, i.e.  either the
directory name or the full path; the name is used if they are the same
length.  The parameters ‘$PWD’ and ‘$OLDPWD’ are never abbreviated in
this fashion.


File: zsh.info,  Node: `=’ Expansion,  Next: Notes,  Prev: Static Named Directories,  Up: Filename Expansion

13.8.3 ‘=’ Expansion
--------------------

If a word begins with an unquoted = and the ‘EQUALS’ option is set, the
remainder of the word is taken as the name of a command.  If a command
exists by that name, the word is replaced by the full pathname of the
command.


File: zsh.info,  Node: Notes,  Prev: `=’ Expansion,  Up: Filename Expansion

13.8.4 Notes
------------

Filename expansion is performed on the right hand side of a parameter
assignment, including those appearing after commands of the ‘typeset’
family.  In this case, the right hand side will be treated as a
colon-separated list in the manner of the ‘PATH’ parameter, so that a ~
or an = following a : is eligible for expansion.  All such behaviour can
be disabled by quoting the ~, the =, or the whole expression (but not
simply the colon); the ‘EQUALS’ option is also respected.

If the option ‘MAGIC_EQUAL_SUBST’ is set, any unquoted shell argument in
the form IDENTIFIER‘=’EXPRESSION becomes eligible for file expansion as
described in the previous paragraph.  Quoting the first = also inhibits
this.


File: zsh.info,  Node: Filename Generation,  Prev: Filename Expansion,  Up: Expansion

13.9 Filename Generation
========================

If a word contains an unquoted instance of one of the characters >>*<<,
(, >>|<<, <, [, or ?, it is regarded as a pattern for filename
generation, unless the ‘GLOB’ option is unset.  ..  index:: single:
GLOB, use of; Program

If the ‘EXTENDED_GLOB’ option is set, ..  index:: single: EXTENDED_GLOB,
use of; Program

the ^ and # characters also denote a pattern; otherwise they are not
treated specially by the shell.

The word is replaced with a list of sorted filenames that match the
pattern.  If no matching pattern is found, the shell gives an error
message, unless the ‘NULL_GLOB’ option is set, ..  index:: single:
NULL_GLOB, use of; Program

in which case the word is deleted; or unless the ‘NOMATCH’ option is
unset, in which case the word is left unchanged.  ..  index:: single:
NOMATCH, use of; Program

In filename generation, the character / must be matched explicitly;
also, a .  must be matched explicitly at the beginning of a pattern or
after a /, unless the ‘GLOB_DOTS’ option is set.  ..  index:: single:
GLOB_DOTS, use of; Program

No filename generation pattern matches the files .  or … In other
instances of pattern matching, the / and .  are not treated specially.

* Menu:

* Glob Operators::
* ksh-like Glob Operators::
* Precedence::
* Globbing Flags::
* Approximate Matching::
* Recursive Globbing::
* Glob Qualifiers::


File: zsh.info,  Node: Glob Operators,  Next: ksh-like Glob Operators,  Up: Filename Generation

13.9.1 Glob Operators
---------------------

   * Matches any string, including the null string.

?

     Matches any character.

[…]

     Matches any of the enclosed characters.  Ranges of characters can
     be specified by separating two characters by a -.  A - or ] may be
     matched by including it as the first character in the list.  ..
     index:: single: character classes; Command

     There are also several named classes of characters, in the form
     [:NAME‘:]’ with the following meanings.  The first set use the
     macros provided by the operating system to test for the given
     character combinations, including any modifications due to local
     language settings, see ‘ctype(3)’:

     ‘[:alnum:]’

          The character is alphanumeric

     ‘[:alpha:]’

          The character is alphabetic

     ‘[:ascii:]’

          The character is 7-bit, i.e.  is a single-byte character
          without the top bit set.

     ‘[:blank:]’

          The character is a blank character

     ‘[:cntrl:]’

          The character is a control character

     ‘[:digit:]’

          The character is a decimal digit

     ‘[:graph:]’

          The character is a printable character other than whitespace

     ‘[:lower:]’

          The character is a lowercase letter

     ‘[:print:]’

          The character is printable

     ‘[:punct:]’

          The character is printable but neither alphanumeric nor
          whitespace

     ‘[:space:]’

          The character is whitespace

     ‘[:upper:]’

          The character is an uppercase letter

     ‘[:xdigit:]’

          The character is a hexadecimal digit

     Another set of named classes is handled internally by the shell and
     is not sensitive to the locale:

     ‘[:IDENT:]’

          The character is allowed to form part of a shell identifier,
          such as a parameter name; this test respects the
          ‘POSIX_IDENTIFIERS’ option

     ‘[:IFS:]’

          The character is used as an input field separator, i.e.  is
          contained in the ‘IFS’ parameter

     ‘[:IFSSPACE:]’

          The character is an IFS white space character; see the
          documentation for ‘IFS’ in *note Parameters Used by the Shell:
          11.

     ‘[:INCOMPLETE:]’

          Matches a byte that starts an incomplete multibyte character.
          Note that there may be a sequence of more than one bytes that
          taken together form the prefix of a multibyte character.  To
          test for a potentially incomplete byte sequence, use the
          pattern ‘[[:INCOMPLETE:]]*’.  This will never match a sequence
          starting with a valid multibyte character.

     ‘[:INVALID:]’

          Matches a byte that does not start a valid multibyte
          character.  Note this may be a continuation byte of an
          incomplete multibyte character as any part of a multibyte
          string consisting of invalid and incomplete multibyte
          characters is treated as single bytes.

     ‘[:WORD:]’

          The character is treated as part of a word; this test is
          sensitive to the value of the ‘WORDCHARS’ parameter

     Note that the square brackets are additional to those enclosing the
     whole set of characters, so to test for a single alphanumeric
     character you need ‘[[:alnum:]]’.  Named character sets can be used
     alongside other types, e.g.  ‘[[:alpha:]0-9]’.

[^…]

[!…]

     Like […], except that it matches any character which is not in the
     given set.

<[X]-[Y]>

     Matches any number in the range X to Y, inclusive.  Either of the
     numbers may be omitted to make the range open-ended; hence <->
     matches any number.  To match individual digits, the […] form is
     more efficient.

     Be careful when using other wildcards adjacent to patterns of this
     form; for example, ‘<0-9>*’ will actually match any number
     whatsoever at the start of the string, since the ‘<0-9>’ will match
     the first digit, and the * will match any others.  This is a trap
     for the unwary, but is in fact an inevitable consequence of the
     rule that the longest possible match always succeeds.  Expressions
     such as ‘<0-9>[^[:digit:]]*’ can be used instead.

(…)

     Matches the enclosed pattern.  This is used for grouping.  If the
     ‘KSH_GLOB’ option is set, then a @, >>*<<, +, ?  or !  immediately
     preceding the ( is treated specially, as detailed below.  The
     option ‘SH_GLOB’ prevents bare parentheses from being used in this
     way, though the ‘KSH_GLOB’ option is still available.

     Note that grouping cannot extend over multiple directories: it is
     an error to have a / within a group (this only applies for patterns
     used in filename generation).  There is one exception: a group of
     the form (PAT‘/)#’ appearing as a complete path segment can match a
     sequence of directories.  For example, ‘foo/(a*/)#bar’ matches
     ‘foo/bar’, ‘foo/any/bar’, ‘foo/any/anyother/bar’, and so on.

X‘|’Y

     Matches either X or Y.  This operator has lower precedence than any
     other.  The | character must be within parentheses, to avoid
     interpretation as a pipeline.  The alternatives are tried in order
     from left to right.

^:var:‘x’

     (Requires ‘EXTENDED_GLOB’ to be set.)  Matches anything except the
     pattern X.  This has a higher precedence than /, so ‘^foo/bar’ will
     search directories in .  except ‘./foo’ for a file named ‘bar’.

X‘~’Y

     (Requires ‘EXTENDED_GLOB’ to be set.)  Match anything that matches
     the pattern X but does not match Y.  This has lower precedence than
     any operator except >>|<<, so ‘*/*~foo/bar’ will search for all
     files in all directories in .  and then exclude ‘foo/bar’ if there
     was such a match.  Multiple patterns can be excluded by
     FOO‘~’BAR‘~’BAZ.  In the exclusion pattern (Y), / and .  are not
     treated specially the way they usually are in globbing.

X‘#’

     (Requires ‘EXTENDED_GLOB’ to be set.)  Matches zero or more
     occurrences of the pattern X.  This operator has high precedence;
     ‘12#’ is equivalent to ‘1(2#)’, rather than ‘(12)#’.  It is an
     error for an unquoted # to follow something which cannot be
     repeated; this includes an empty string, a pattern already followed
     by ##, or parentheses when part of a ‘KSH_GLOB’ pattern (for
     example, !(FOO‘)#’ is invalid and must be replaced by
     >>*<<(!(FOO‘))’).

X‘##’

     (Requires ‘EXTENDED_GLOB’ to be set.)  Matches one or more
     occurrences of the pattern X.  This operator has high precedence;
     ‘12##’ is equivalent to ‘1(2##)’, rather than ‘(12)##’.  No more
     than two active # characters may appear together.  (Note the
     potential clash with glob qualifiers in the form ‘1(2##)’ which
     should therefore be avoided.)


File: zsh.info,  Node: ksh-like Glob Operators,  Next: Precedence,  Prev: Glob Operators,  Up: Filename Generation

13.9.2 ksh-like Glob Operators
------------------------------

If the ‘KSH_GLOB’ option is set, the effects of parentheses can be
modified by a preceding @, >>*<<, +, ?  or !.  This character need not
be unquoted to have special effects, but the ( must be.

@(…)

     Match the pattern in the parentheses.  (Like (…).)

>>*<<(…)

     Match any number of occurrences.  (Like (…)#, except that recursive
     directory searching is not supported.)

+(…)

     Match at least one occurrence.  (Like (…)##, except that recursive
     directory searching is not supported.)

?(…)

     Match zero or one occurrence.  (Like (>>|<<…).)

!(…)

     Match anything but the expression in parentheses.  (Like (^(…)).)


File: zsh.info,  Node: Precedence,  Next: Globbing Flags,  Prev: ksh-like Glob Operators,  Up: Filename Generation

13.9.3 Precedence
-----------------

The precedence of the operators given above is (highest) ^, /, ~, |
(lowest); the remaining operators are simply treated from left to right
as part of a string, with # and ## applying to the shortest possible
preceding unit (i.e.  a character, ?, […], <…>, or a parenthesised
expression).  As mentioned above, a / used as a directory separator may
not appear inside parentheses, while a | must do so; in patterns used in
other contexts than filename generation (for example, in ‘case’
statements and tests within [[…]]), a / is not special; and / is also
not special after a ~ appearing outside parentheses in a filename
pattern.


File: zsh.info,  Node: Globbing Flags,  Next: Approximate Matching,  Prev: Precedence,  Up: Filename Generation

13.9.4 Globbing Flags
---------------------

There are various flags which affect any text to their right up to the
end of the enclosing group or to the end of the pattern; they require
the ‘EXTENDED_GLOB’ option.  All take the form (#:var:‘X’‘)’ where X may
have one of the following forms:

‘i’

     Case insensitive: upper or lower case characters in the pattern
     match upper or lower case characters.

‘l’

     Lower case characters in the pattern match upper or lower case
     characters; upper case characters in the pattern still only match
     upper case characters.

‘I’

     Case sensitive: locally negates the effect of ‘i’ or ‘l’ from that
     point on.

‘b’

     Activate backreferences for parenthesised groups in the pattern;
     this does not work in filename generation.  When a pattern with a
     set of active parentheses is matched, the strings matched by the
     groups are stored in the array ‘$match’, the indices of the
     beginning of the matched parentheses in the array ‘$mbegin’, and
     the indices of the end in the array ‘$mend’, with the first element
     of each array corresponding to the first parenthesised group, and
     so on.  These arrays are not otherwise special to the shell.  The
     indices use the same convention as does parameter substitution, so
     that elements of ‘$mend’ and ‘$mbegin’ may be used in subscripts;
     the ‘KSH_ARRAYS’ option is respected.  Sets of globbing flags are
     not considered parenthesised groups; only the first nine active
     parentheses can be referenced.

     For example,

           foo="a_string_with_a_message"
           if [[ $foo = (a|an)_(#b)(*) ]]; then
             print ${foo[$mbegin[1],$mend[1]]}
           fi

     prints ‘string_with_a_message’.  Note that the first set of
     parentheses is before the ‘(#b)’ and does not create a
     backreference.

     Backreferences work with all forms of pattern matching other than
     filename generation, but note that when performing matches on an
     entire array, such as ${ARRAY‘#’PATTERN‘}’, or a global
     substitution, such as ${PARAM‘//’PAT‘/’REPL‘}’, only the data for
     the last match remains available.  In the case of global
     replacements this may still be useful.  See the example for the ‘m’
     flag below.

     The numbering of backreferences strictly follows the order of the
     opening parentheses from left to right in the pattern string,
     although sets of parentheses may be nested.  There are special
     rules for parentheses followed by # or ##.  Only the last match of
     the parenthesis is remembered: for example, in ‘[[ abab =
     (#b)([ab])# ]]’, only the final ‘b’ is stored in ‘match[1]’.  Thus
     extra parentheses may be necessary to match the complete segment:
     for example, use ‘X((ab|cd)#)Y’ to match a whole string of either
     ‘ab’ or ‘cd’ between ‘X’ and ‘Y’, using the value of ‘$match[1]’
     rather than ‘$match[2]’.

     If the match fails none of the parameters is altered, so in some
     cases it may be necessary to initialise them beforehand.  If some
     of the backreferences fail to match – which happens if they are in
     an alternate branch which fails to match, or if they are followed
     by # and matched zero times – then the matched string is set to the
     empty string, and the start and end indices are set to -1.

     Pattern matching with backreferences is slightly slower than
     without.

‘B’

     Deactivate backreferences, negating the effect of the ‘b’ flag from
     that point on.

‘c’N‘,’M

     The flag ‘(#c’N‘,’M‘)’ can be used anywhere that the # or ##
     operators can be used except in the expressions (‘/)# and (’/)## in
     filename generation, where / has special meaning; it cannot be
     combined with other globbing flags and a bad pattern error occurs
     if it is misplaced.  It is equivalent to the form {N‘,’M‘}’ in
     regular expressions.  The previous character or group is required
     to match between N and M times, inclusive.  The form ‘(#c’N‘)’
     requires exactly ‘N’ matches; ‘(#c,’M‘)’ is equivalent to
     specifying N as 0; ‘(#c’N‘,)’ specifies that there is no maximum
     limit on the number of matches.

‘m’

     Set references to the match data for the entire string matched;
     this is similar to backreferencing and does not work in filename
     generation.  The flag must be in effect at the end of the pattern,
     i.e.  not local to a group.  The parameters ‘$MATCH’, ‘$MBEGIN’ and
     ‘$MEND’ will be set to the string matched and to the indices of the
     beginning and end of the string, respectively.  This is most useful
     in parameter substitutions, as otherwise the string matched is
     obvious.

     For example,

           arr=(veldt jynx grimps waqf zho buck)
           print ${arr//(#m)[aeiou]/${(U)MATCH}}

     forces all the matches (i.e.  all vowels) into uppercase, printing
     ‘vEldt jynx grImps wAqf zhO bUck’.

     Unlike backreferences, there is no speed penalty for using match
     references, other than the extra substitutions required for the
     replacement strings in cases such as the example shown.

‘M’

     Deactivate the ‘m’ flag, hence no references to match data will be
     created.

‘a’NUM

     Approximate matching: NUM errors are allowed in the string matched
     by the pattern.  The rules for this are described in the next
     subsection.

‘s’, ‘e’

     Unlike the other flags, these have only a local effect, and each
     must appear on its own: ‘(#s)’ and ‘(#e)’ are the only valid forms.
     The ‘(#s)’ flag succeeds only at the start of the test string, and
     the ‘(#e)’ flag succeeds only at the end of the test string; they
     correspond to ^ and $ in standard regular expressions.  They are
     useful for matching path segments in patterns other than those in
     filename generation (where path segments are in any case treated
     separately).  For example, ‘*((#s)|/)test((#e)|/)*’ matches a path
     segment ‘test’ in any of the following strings: ‘test’,
     ‘test/at/start’, ‘at/end/test’, ‘in/test/middle’.

     Another use is in parameter substitution; for example
     ‘${array/(#s)A*Z(#e)}’ will remove only elements of an array which
     match the complete pattern ‘A*Z’.  There are other ways of
     performing many operations of this type, however the combination of
     the substitution operations / and // with the ‘(#s)’ and ‘(#e)’
     flags provides a single simple and memorable method.

     Note that assertions of the form ‘(^(#s))’ also work, i.e.  match
     anywhere except at the start of the string, although this actually
     means ‘anything except a zero-length portion at the start of the
     string’; you need to use ‘(""~(#s))’ to match a zero-length portion
     of the string not at the start.

‘q’

     A ‘q’ and everything up to the closing parenthesis of the globbing
     flags are ignored by the pattern matching code.  This is intended
     to support the use of glob qualifiers, see below.  The result is
     that the pattern ‘(#b)(*).c(#q.)’ can be used both for globbing and
     for matching against a string.  In the former case, the ‘(#q.)’
     will be treated as a glob qualifier and the ‘(#b)’ will not be
     useful, while in the latter case the ‘(#b)’ is useful for
     backreferences and the ‘(#q.)’ will be ignored.  Note that colon
     modifiers in the glob qualifiers are also not applied in ordinary
     pattern matching.

‘u’

     Respect the current locale in determining the presence of multibyte
     characters in a pattern, provided the shell was compiled with
     ‘MULTIBYTE_SUPPORT’.  This overrides the ‘MULTIBYTE’ option; the
     default behaviour is taken from the option.  Compare ‘U’.
     (Mnemonic: typically multibyte characters are from Unicode in the
     UTF-8 encoding, although any extension of ASCII supported by the
     system library may be used.)

‘U’

     All characters are considered to be a single byte long.  The
     opposite of ‘u’.  This overrides the ‘MULTIBYTE’ option.

For example, the test string ‘fooxx’ can be matched by the pattern
‘(#i’‘)FOOXX’, but not by ‘(#l’‘)FOOXX’, ‘(#i’‘)FOO’‘(#I’‘)XX’ or
‘((#i’‘)FOOX’‘)X’.  The string ‘(#ia2’‘)readme’ specifies
case-insensitive matching of ‘readme’ with up to two errors.

When using the ksh syntax for grouping both ‘KSH_GLOB’ and
‘EXTENDED_GLOB’ must be set and the left parenthesis should be preceded
by @.  Note also that the flags do not affect letters inside […] groups,
in other words ‘(#i’‘)[a-z]’ still matches only lowercase letters.
Finally, note that when examining whole paths case-insensitively every
directory must be searched for all files which match, so that a pattern
of the form ‘(#i’‘)/foo/bar/...’ is potentially slow.


File: zsh.info,  Node: Approximate Matching,  Next: Recursive Globbing,  Prev: Globbing Flags,  Up: Filename Generation

13.9.5 Approximate Matching
---------------------------

When matching approximately, the shell keeps a count of the errors
found, which cannot exceed the number specified in the ‘(#a’NUM‘)’
flags.  Four types of error are recognised:

  1. Different characters, as in ‘fooxbar’ and ‘fooybar’.

  2. Transposition of characters, as in ‘banana’ and ‘abnana’.

  3. A character missing in the target string, as with the pattern
     ‘road’ and target string ‘rod’.

  4. An extra character appearing in the target string, as with ‘stove’
     and ‘strove’.

Thus, the pattern ‘(#a3’‘)abcd’ matches ‘dcba’, with the errors
occurring by using the first rule twice and the second once, grouping
the string as ‘[d][cb][a]’ and ‘[a][bc][d]’.

Non-literal parts of the pattern must match exactly, including
characters in character ranges: hence ‘(#a1’)???  matches strings of
length four, by applying rule 4 to an empty part of the pattern, but not
strings of length two, since all the ?  must match.  Other characters
which must match exactly are initial dots in filenames (unless the
‘GLOB_DOTS’ option is set), and all slashes in filenames, so that ‘a/bc’
is two errors from ‘ab/c’ (the slash cannot be transposed with another
character).  Similarly, errors are counted separately for non-contiguous
strings in the pattern, so that ‘(ab|cd’‘)ef’ is two errors from ‘aebf’.

When using exclusion via the ~ operator, approximate matching is treated
entirely separately for the excluded part and must be activated
separately.  Thus, ‘(#a1’‘)README~READ_ME’ matches ‘READ.ME’ but not
‘READ_ME’, as the trailing ‘READ_ME’ is matched without approximation.
However, ‘(#a1’‘)README~(#a1’‘)READ_ME’ does not match any pattern of
the form ‘READ’?‘ME’ as all such forms are now excluded.

Apart from exclusions, there is only one overall error count; however,
the maximum errors allowed may be altered locally, and this can be
delimited by grouping.  For example, ‘(#a1’‘)cat’‘((#a0’‘)dog’‘)fox’
allows one error in total, which may not occur in the ‘dog’ section, and
the pattern ‘(#a1’‘)cat’‘(#a0’‘)dog’‘(#a1’‘)fox’ is equivalent.  Note
that the point at which an error is first found is the crucial one for
establishing whether to use approximation; for example,
‘(#a1)abc(#a0)xyz’ will not match ‘abcdxyz’, because the error occurs at
the ‘x’, where approximation is turned off.

Entire path segments may be matched approximately, so that
‘(#a1)/foo/d/is/available/at/the/bar’ allows one error in any path
segment.  This is much less efficient than without the ‘(#a1)’, however,
since every directory in the path must be scanned for a possible
approximate match.  It is best to place the ‘(#a1)’ after any path
segments which are known to be correct.


File: zsh.info,  Node: Recursive Globbing,  Next: Glob Qualifiers,  Prev: Approximate Matching,  Up: Filename Generation

13.9.6 Recursive Globbing
-------------------------

A pathname component of the form (FOO‘/)#’ matches a path consisting of
zero or more directories matching the pattern FOO.

As a shorthand, >>**<</ is equivalent to (>>*<</)#; note that this
therefore matches files in the current directory as well as
subdirectories.  Thus:

      ls -ld -- (*/)#bar

or

      ls -ld -- **/bar

does a recursive directory search for files named ‘bar’ (potentially
including the file ‘bar’ in the current directory).  This form does not
follow symbolic links; the alternative form >>**<<>>*<</ does, but is
otherwise identical.  Neither of these can be combined with other forms
of globbing within the same path segment; in that case, the * operators
revert to their usual effect.

Even shorter forms are available when the option ‘GLOB_STAR_SHORT’ is
set.  In that case if no / immediately follows a ** or >>**<<* they are
treated as if both a / plus a further * are present.  Hence:

      setopt GLOBSTARSHORT
      ls -ld -- **.c

is equivalent to

      ls -ld -- **/*.c


File: zsh.info,  Node: Glob Qualifiers,  Prev: Recursive Globbing,  Up: Filename Generation

13.9.7 Glob Qualifiers
----------------------

Patterns used for filename generation may end in a list of qualifiers
enclosed in parentheses.  The qualifiers specify which filenames that
otherwise match the given pattern will be inserted in the argument list.

If the option ‘BARE_GLOB_QUAL’ is set, then a trailing set of
parentheses containing no unquoted | or ( characters (or ~ if it is
special due to ‘EXTENDED_GLOB’) is taken as a set of glob qualifiers.  A
glob subexpression that would normally be taken as glob qualifiers, for
example ‘(^x)’, can be forced to be treated as part of the glob pattern
by doubling the parentheses, in this case producing ‘((^x))’.

If the option ‘EXTENDED_GLOB’ is set, a different syntax for glob
qualifiers is available, namely ‘(#q’X‘)’ where X is any of the same
glob qualifiers used in the other format.  The qualifiers must still
appear at the end of the pattern.  However, with this syntax multiple
glob qualifiers may be chained together.  They are treated as a logical
AND of the individual sets of flags.  Also, as the syntax is
unambiguous, the expression will be treated as glob qualifiers just as
long any parentheses contained within it are balanced; appearance of
>>|<<, ( or ~ does not negate the effect.  Note that qualifiers will be
recognised in this form even if a bare glob qualifier exists at the end
of the pattern, for example ‘*(#q*)(.)’ will recognise executable
regular files if both options are set; however, mixed syntax should
probably be avoided for the sake of clarity.  Note that within
conditions using the [[ form the presence of a parenthesised expression
‘(#q’…‘)’ at the end of a string indicates that globbing should be
performed; the expression may include glob qualifiers, but it is also
valid if it is simply ‘(#q)’.  This does not apply to the right hand
side of pattern match operators as the syntax already has special
significance.

With either syntax, normal quoting and expansion rules apply to the list
of qualifiers, so that the forms >>*<<(.), ‘*(#q".")’, and ‘qual=.;’ …
‘*(#q$qual)’ are generally equivalent.

A qualifier may be any one of the following:

/

     directories

‘F’

     ‘full’ (i.e.  non-empty) directories.  Note that the opposite sense
     ‘(^F’) expands to empty directories and all non-directories.  Use
     ‘(/^F’) for empty directories.

.

     plain files

@

     symbolic links

=

     sockets

‘p’

     named pipes (FIFOs)

   * executable plain files (0100 or 0010 or 0001)

%

     device files (character or block special)

‘%b’

     block special files

‘%c’

     character special files

‘r’

     owner-readable files (0400)

‘w’

     owner-writable files (0200)

‘x’

     owner-executable files (0100)

‘A’

     group-readable files (0040)

‘I’

     group-writable files (0020)

‘E’

     group-executable files (0010)

‘R’

     world-readable files (0004)

‘W’

     world-writable files (0002)

‘X’

     world-executable files (0001)

‘s’

     setuid files (04000)

‘S’

     setgid files (02000)

‘t’

     files with the sticky bit (01000)

‘f’SPEC

     files with access rights matching SPEC.  This SPEC may be a octal
     number optionally preceded by a =, a +, or a -.  If none of these
     characters is given, the behavior is the same as for =.  The octal
     number describes the mode bits to be expected, if combined with a
     =, the value given must match the file-modes exactly, with a +, at
     least the bits in the given number must be set in the file-modes,
     and with a -, the bits in the number must not be set.  Giving a ?
     instead of a octal digit anywhere in the number ensures that the
     corresponding bits in the file-modes are not checked, this is only
     useful in combination with =.

     If the qualifier ‘f’ is followed by any other character anything up
     to the next matching character ([, {, and < match ], }, and >
     respectively, any other character matches itself) is taken as a
     list of comma-separated SUB-SPECs.  Each SUB-SPEC may be either an
     octal number as described above or a list of any of the characters
     ‘u’, ‘g’, ‘o’, and ‘a’, followed by a =, a +, or a -, followed by a
     list of any of the characters ‘r’, ‘w’, ‘x’, ‘s’, and ‘t’, or an
     octal digit.  The first list of characters specify which access
     rights are to be checked.  If a ‘u’ is given, those for the owner
     of the file are used, if a ‘g’ is given, those of the group are
     checked, a ‘o’ means to test those of other users, and the ‘a’ says
     to test all three groups.  The =, +, and - again says how the modes
     are to be checked and have the same meaning as described for the
     first form above.  The second list of characters finally says which
     access rights are to be expected: ‘r’ for read access, ‘w’ for
     write access, ‘x’ for the right to execute the file (or to search a
     directory), ‘s’ for the setuid and setgid bits, and ‘t’ for the
     sticky bit.

     Thus, ‘*(f70?)’ gives the files for which the owner has read,
     write, and execute permission, and for which other group members
     have no rights, independent of the permissions for other users.
     The pattern ‘*(f-100)’ gives all files for which the owner does not
     have execute permission, and ‘*(f:gu+w,o-rx:)’ gives the files for
     which the owner and the other members of the group have at least
     write permission, and for which other users don’t have read or
     execute permission.

‘e’STRING

+:var:‘cmd’

     The STRING or CMD will be executed as shell code.  The filename
     will be included in the list if and only if the code returns a zero
     status (usually the status of the last command).

     In the first form, the first character after the ‘e’ will be used
     as a separator and anything up to the next matching separator will
     be taken as the STRING; (, [, {, and < match ), ], }, and >,
     respectively, while any other character matches itself.  As with
     glob qualifiers in general, normal quoting and expansion rules
     apply to the entire STRING.  Thus expansions must be quoted to
     prevent them from being expanded before globbing is done, and
     quoting does not normally protect the end separator if it appears
     in the code.  However, if an unquoted metacharacter is used as the
     separator, its quoted/expanded form is protected.

     STRING is then executed as shell code.  The string ‘globqual’ is
     appended to the array ‘zsh_eval_context’ the duration of execution.

     During the execution of STRING the filename currently being tested
     is available in the parameter ‘REPLY’; the parameter may be altered
     to a string to be inserted into the list instead of the original
     filename.  In addition, the parameter ‘reply’ may be set to an
     array or a string, which overrides the value of ‘REPLY’.  If set to
     an array, the latter is inserted into the command line word by
     word.

     For example, suppose a directory contains a single file ‘lonely’.
     Then the expression ‘*(e:reply=(${REPLY}{1,2})':)’’ will cause the
     words ‘lonely1’ and ‘lonely2’ to be inserted into the command line.
     Note the quoting of STRING.

     The form +:var:‘cmd’ has the same effect, but no delimiters appear
     around CMD.  Instead, CMD is taken as the longest sequence of
     characters following the + that are alphanumeric or underscore.
     Typically CMD will be the name of a shell function that contains
     the appropriate test.  For example,

           nt() { [[ $REPLY -nt $NTREF ]] }
           NTREF=reffile
           ls -ld -- *(+nt)

     lists all files in the directory that have been modified more
     recently than ‘reffile’.

‘d’DEV

     files on the device DEV

‘l’[->>|<<+]:var:‘ct’

     files having a link count less than CT (-), greater than CT (+), or
     equal to CT

‘U’

     files owned by the effective user ID

‘G’

     files owned by the effective group ID

‘u’ID

     files owned by user ID ID if that is a number.  Otherwise, ID
     specifies a user name: the character after the ‘u’ will be taken as
     a separator and the string between it and the next matching
     separator will be taken as a user name.  The starting separators [,
     {, and < match the final separators ], }, and >, respectively; any
     other character matches itself.  The selected files are those owned
     by this user.  For example, ‘u:foo:’ or ‘u[foo]’ selects files
     owned by user ‘foo’.

‘g’ID

     like ‘u’ID but with group IDs or names

‘a’[‘Mwhms’][->>|<<+]:var:‘n’

     files accessed exactly N days ago.  Files accessed within the last
     N days are selected using a negative value for N (-N).  Files
     accessed more than N days ago are selected by a positive N value
     (+:var:‘n’).  Optional unit specifiers ‘M’, ‘w’, ‘h’, ‘m’ or ‘s’
     (e.g.  ‘ah5’) cause the check to be performed with months (of 30
     days), weeks, hours, minutes or seconds instead of days,
     respectively.  An explicit ‘d’ for days is also allowed.

     Any fractional part of the difference between the access time and
     the current part in the appropriate units is ignored in the
     comparison.  For instance, ‘echo *(ah-5)’ would echo files accessed
     within the last five hours, while ‘echo *(ah+5)’ would echo files
     accessed at least six hours ago, as times strictly between five and
     six hours are treated as five hours.

‘m’[‘Mwhms’][->>|<<+]:var:‘n’

     like the file access qualifier, except that it uses the file
     modification time.

‘c’[‘Mwhms’][->>|<<+]:var:‘n’

     like the file access qualifier, except that it uses the file inode
     change time.

‘L’[+|-]:var:‘n’

     files less than N bytes (-), more than N bytes (+), or exactly N
     bytes in length.

     If this flag is directly followed by a ‘size specifier’ ‘k’ (‘K’),
     ‘m’ (‘M’), or ‘p’ (‘P’) (e.g.  ‘Lk-50’) the check is performed with
     kilobytes, megabytes, or blocks (of 512 bytes) instead.  (On some
     systems additional specifiers are available for gigabytes, ‘g’ or
     ‘G’, and terabytes, ‘t’ or ‘T’.)  If a size specifier is used a
     file is regarded as “exactly” the size if the file size rounded up
     to the next unit is equal to the test size.  Hence ‘*(Lm1)’ matches
     files from 1 byte up to 1 Megabyte inclusive.  Note also that the
     set of files “less than” the test size only includes files that
     would not match the equality test; hence ‘*(Lm-1)’ only matches
     files of zero size.

^

     negates all qualifiers following it

   - toggles between making the qualifiers work on symbolic links (the
     default) and the files they point to, if any; any symbolic link for
     whose target the ‘stat’ system call fails (whatever the cause of
     the failure) is treated as a file in its own right

‘M’

     sets the ‘MARK_DIRS’ option for the current pattern ..  index::
     single: MARK_DIRS, setting in pattern; Program

‘T’

     appends a trailing qualifier mark to the filenames, analogous to
     the ‘LIST_TYPES’ option, for the current pattern (overrides ‘M’)

‘N’

     sets the ‘NULL_GLOB’ option for the current pattern ..  index::
     single: NULL_GLOB, setting in pattern; Program

‘D’

     sets the ‘GLOB_DOTS’ option for the current pattern ..  index::
     single: GLOB_DOTS, setting in pattern; Program

‘n’

     sets the ‘NUMERIC_GLOB_SORT’ option for the current pattern ..
     index:: single: NUMERIC_GLOB_SORT, setting in pattern; Program

‘Y’N

     enables short-circuit mode: the pattern will expand to at most N
     filenames.  If more than N matches exist, only the first N matches
     in directory traversal order will be considered.

     Any sorting specified with an ‘o’C or ‘O’C qualifier is applied
     ‘after’ the N matches are returned; ‘oN’ is implied otherwise.

‘o’C

     specifies how the names of the files should be sorted.  The
     following values of C sort in the following ways:

     ‘n’

          By name.

     ‘L’

          By the size (length) of the files.

     ‘l’

          By number of links.

     ‘a’

          By time of last access, youngest first.

     ‘m’

          By time of last modification, youngest first.

     ‘c’

          By time of last inode change, youngest first.

     ‘d’

          By directories: files in subdirectories appear before those in
          the current directory at each level of the search – this is
          best combined with other criteria, for example ‘odon’ to sort
          on names for files within the same directory.

     ‘N’

          No sorting is performed.

     ‘e’STRING

     +:var:‘cmd’

          Sort by shell code (see below).

     Note that the modifiers ^ and - are used, so ‘*(^-oL)’ gives a list
     of all files sorted by file size in descending order, following any
     symbolic links.  Unless ‘oN’ is used, multiple order specifiers may
     occur to resolve ties.

     The default sorting is ‘n’ (by name) unless the ‘Y’ glob qualifier
     is used, in which case it is ‘N’ (unsorted).

     ‘oe’ and ‘o+’ are special cases; they are each followed by shell
     code, delimited as for the ‘e’ glob qualifier and the + glob
     qualifier respectively (see above).  The code is executed for each
     matched file with the parameter ‘REPLY’ set to the name of the file
     on entry and ‘globsort’ appended to ‘zsh_eval_context’.  The code
     should modify the parameter ‘REPLY’ in some fashion.  On return,
     the value of the parameter is used instead of the file name as the
     string on which to sort.  Unlike other sort operators, ‘oe’ and
     ‘o+’ may be repeated, but note that the maximum number of sort
     operators of any kind that may appear in any glob expression is 12.

‘O’C

     like ‘o’, but sorts in descending order; i.e.  ‘*(^o’C‘)’ is the
     same as ‘*(O’C‘)’ and ‘*(^O’C‘)’ is the same as ‘*(o’C‘)’; ‘Od’
     puts files in the current directory before those in subdirectories
     at each level of the search.

[BEG[,:var:‘end’]]

     specifies which of the matched filenames should be included in the
     returned list.  The syntax is the same as for array subscripts.
     BEG and the optional END may be mathematical expressions.  As in
     parameter subscripting they may be negative to make them count from
     the last match backward.  E.g.: ‘*(-OL[1,3])’ gives a list of the
     names of the three largest files.

‘P’STRING

     The STRING will be prepended to each glob match as a separate word.
     STRING is delimited in the same way as arguments to the ‘e’ glob
     qualifier described above.  The qualifier can be repeated; the
     words are prepended separately so that the resulting command line
     contains the words in the same order they were given in the list of
     glob qualifiers.

     A typical use for this is to prepend an option before all
     occurrences of a file name; for example, the pattern ‘*(P:-f:)’
     produces the command line arguments ‘-f’ FILE1 ‘-f’ FILE2 …

     If the modifier ^ is active, then STRING will be appended instead
     of prepended.  Prepending and appending is done independently so
     both can be used on the same glob expression; for example by
     writing ‘*(P:foo:^P:bar:^P:baz:)’ which produces the command line
     arguments ‘foo’ ‘baz’ FILE1 ‘bar’ …

Multiple consecutive qualifiers are joined into a list by implicit
logical AND. More than one of these lists can be combined using comma ,
as logical OR. The whole list matches if at least one of the sublists
matches.  Some qualifiers, however, affect all matches generated,
independent of the sublist in which they are given.  These are the
qualifiers ‘M’, ‘T’, ‘N’, ‘D’, ‘n’, ‘o’, ‘O’ and the subscripts given in
brackets ([…‘]’).

If a : appears in a qualifier list, the remainder of the expression in
parenthesis is interpreted as a modifier (see *note Modifiers: 6b. in
*note History Expansion: 66.).  Each modifier must be introduced by a
separate :.  Note also that the result after modification does not have
to be an existing file.  The name of any existing file can be followed
by a modifier of the form (:…‘)’ even if no actual filename generation
is performed, although note that the presence of the parentheses causes
the entire expression to be subjected to any global pattern matching
options such as ‘NULL_GLOB’.  Thus:

      ls -ld -- *(-/)

lists all directories and symbolic links that point to directories, and

      ls -ld -- *(-@)

lists all broken symbolic links, and

      ls -ld -- *(%W)

lists all world-writable device files in the current directory, and

      ls -ld -- *(W,X)

lists all files in the current directory that are world-writable or
world-executable, and

      print -rC1 /tmp/foo*(u0^@:t)

outputs the basename of all root-owned files beginning with the string
‘foo’ in ‘/tmp’, ignoring symlinks, and

      ls -ld -- *.*~(lex|parse).[ch](^D^l1)

lists all files having a link count of one whose names contain a dot
(but not those starting with a dot, since ‘GLOB_DOTS’ is explicitly
switched off) except for ‘lex.c’, ‘lex.h’, ‘parse.c’ and ‘parse.h’.

      print -rC1 b*.pro(#q:s/pro/shmo/)(#q.:s/builtin/shmiltin/)

demonstrates how colon modifiers and other qualifiers may be chained
together.  The ordinary qualifier .  is applied first, then the colon
modifiers in order from left to right.  So if ‘EXTENDED_GLOB’ is set and
the base pattern matches the regular file ‘builtin.pro’, the shell will
print ‘shmiltin.shmo’.


File: zsh.info,  Node: Parameters,  Next: Options<2>,  Prev: Expansion,  Up: Top

14 Parameters
*************

* Menu:

* Description: Description<2>.
* Array Parameters::
* Positional Parameters::
* Local Parameters::
* Named References: Named References<2>.
* Parameters Set by the Shell::
* Parameters Used by the Shell::


File: zsh.info,  Node: Description<2>,  Next: Array Parameters,  Up: Parameters

14.1 Description
================

A parameter has a name, a value, and a number of attributes.
User-assignable parameter names may contain alphanumeric characters,
underscores, and (per the description of namespaces below) dots.  They
may not begin with a number, except for positional parameters (‘$1’,
‘$2’, etc.), whose names consist ‘only’ of numbers.  There are also
special shell parameters with single-character names such as ‘*’, ‘@’,
‘#’, ‘?’, ‘-’, ‘$’, and ‘!’.  These are described below.  A parameter
whose name begins with an alphanumeric or underscore is also referred to
as a ‘variable’.

The attributes of a parameter determine the ‘type’ of its value, often
referred to as the parameter type or variable type, and also control
other processing that may be applied to the value when it is referenced.
The value type may be a ‘scalar’ (a string, an integer, or a floating
point number), an array (indexed numerically), or an ‘associative’ array
(an unordered set of name-value pairs, indexed by name, also referred to
as a ‘hash’).

Named scalar parameters may have the ‘exported’, ‘-x’, attribute, to
copy them into the process environment, which is then passed from the
shell to any new processes that it starts.  Exported parameters are
called ‘environment variables’.  The shell also ‘imports’ environment
variables at startup time and automatically marks the corresponding
parameters as exported.  Some environment variables are not imported for
reasons of security or because they would interfere with the correct
operation of other shell features.

Parameters may also be ‘special’, that is, they have a predetermined
meaning to the shell.  Special parameters cannot have their type changed
or their readonly attribute turned off, and if a special parameter is
unset, then later recreated, the special properties will be retained.

To declare the type of a parameter, or to assign a string or numeric
value to a scalar parameter, use the ‘typeset’ builtin.  ..  index::
single: typeset, use of; Function

The value of a scalar parameter may also be assigned by writing: ..
index:: single: assignment; Command

     NAME‘=’VALUE

The NAME in an assignment may optionally include a ‘namespace’ prefix:

     ‘.’NAMESPACE‘.’PARAMETER‘=’VALUE

Namespaces have no special meaning to the shell except that parameters
with a ‘.’ prefix are not listed by the ‘set’ builtin, nor shown by the
‘typeset’ builtin unless explicitly named or the ‘-m’ option is used.
They provide a convenient way to group related variables.  Note that,
for support of possible future features, the first ‘.’ is optional, but
omitting it is discouraged.  Note also that a name starting with a ‘.’
does not refer to the same parameter as one that does not, eg,
‘.foo.bar’ and ‘foo.bar’ are distinct parameters.  Unlike ksh, a
namespace need not be declared before it is referenced.

In scalar assignment, VALUE is expanded as a single string, in which the
elements of arrays are joined together; filename expansion is not
performed unless the option ‘GLOB_ASSIGN’ is set.

When the integer attribute, ‘-i’, or a floating point attribute, ‘-E’ or
‘-F’, is set for NAME, the VALUE is subject to arithmetic evaluation.
Furthermore, by replacing ‘=’ with ‘+=’, a parameter can be incremented
or appended to.  See *note Array Parameters: 1b. and *note Arithmetic
Evaluation: 89. for additional forms of assignment.

Note that assignment may implicitly change the attributes of a
parameter.  For example, assigning a number to a variable in arithmetic
evaluation may change its type to integer or float, and with
‘GLOB_ASSIGN’ assigning a pattern to a variable may change its type to
an array.

To reference the value of a parameter, write ‘$’NAME or ‘${’NAME‘}’.
The latter form is required when NAME includes a namespace prefix.  See
*note Parameter Expansion: 1a. for complete details.  That section also
explains the effect of the difference between scalar and array
assignment on parameter expansion.


File: zsh.info,  Node: Array Parameters,  Next: Positional Parameters,  Prev: Description<2>,  Up: Parameters

14.2 Array Parameters
=====================

To assign an array value, write one of: ..  index:: single: set, use of;
Function

     ‘set -A’ NAME VALUE …

     NAME‘=(’VALUE …‘‘)‘‘

     NAME‘=([’KEY‘]=’VALUE …‘‘)‘‘

If no parameter NAME exists, an ordinary array parameter is created.  If
the parameter NAME exists and is a scalar, it is replaced by a new
array.

In the third form, KEY is an expression that will be evaluated in
arithmetic context (in its simplest form, an integer) that gives the
index of the element to be assigned with VALUE.  In this form any
elements not explicitly mentioned that come before the largest index to
which a value is assigned are assigned an empty string.  The indices may
be in any order.  Note that this syntax is strict: ‘[’ and ‘]=’ must not
be quoted, and KEY may not consist of the unquoted string ‘]=’, but is
otherwise treated as a simple string.  The enhanced forms of subscript
expression that may be used when directly subscripting a variable name,
described in *note Array Subscripts: 8a, are not available.

The syntaxes with and without the explicit key may be mixed.  An
implicit KEY is deduced by incrementing the index from the previously
assigned element.  Note that it is not treated as an error if latter
assignments in this form overwrite earlier assignments.

For example, assuming the option ‘KSH_ARRAYS’ is not set, the following:

      array=(one [3]=three four)

causes the array variable ‘array’ to contain four elements ‘one’, an
empty string, ‘three’ and ‘four’, in that order.

In the forms where only VALUE is specified, full command line expansion
is performed.

In the ‘[’KEY‘]=’VALUE form, both KEY and VALUE undergo all forms of
expansion allowed for single word shell expansions (this does not
include filename generation); these are as performed by the parameter
expansion flag ‘(e)’ as described in *note Parameter Expansion Flags:
6e.  Nested parentheses may surround VALUE and are included as part of
the value, which is joined into a plain string; this differs from ksh
which allows the values themselves to be arrays.  A future version of
zsh may support that.  To cause the brackets to be interpreted as a
character class for filename generation, and therefore to treat the
resulting list of files as a set of values, quote the equal sign using
any form of quoting.  Example:

     NAME‘=([a-z]'='*)’

To append to an array without changing the existing values, use one of
the following:

     NAME‘+=(’VALUE …‘‘)‘‘

     NAME‘+=([’KEY‘]=’VALUE …‘‘)‘‘

In the second form KEY may specify an existing index as well as an index
off the end of the old array; any existing value is overwritten by
VALUE.  Also, it is possible to use ‘[’KEY‘]+=’VALUE to append to the
existing value at that index.

Within the parentheses on the right hand side of either form of the
assignment, newlines and semicolons are treated the same as white space,
separating individual VALUEs.  Any consecutive sequence of such
characters has the same effect.

Ordinary array parameters may also be explicitly declared with: ..
index:: single: typeset, use of; Function

     ‘typeset -a’ NAME

Associative arrays ‘must’ be declared before assignment, by using:

     ‘typeset -A’ NAME

When NAME refers to an associative array, the list in an assignment is
interpreted as alternating keys and values:

     ‘set -A’ NAME KEY VALUE …

     NAME‘=(’KEY VALUE …‘‘)‘‘

     NAME‘=([’KEY‘]=’VALUE …‘‘)‘‘

Note that only one of the two syntaxes above may be used in any given
assignment; the forms may not be mixed.  This is unlike the case of
numerically indexed arrays.

Every KEY must have a VALUE in this case.  Note that this assigns to the
entire array, deleting any elements that do not appear in the list.  The
append syntax may also be used with an associative array:

     NAME‘+=(’KEY VALUE …‘‘)‘‘

     NAME‘+=([’KEY‘]=’VALUE …‘‘)‘‘

This adds a new key/value pair if the key is not already present, and
replaces the value for the existing key if it is.  In the second form it
is also possible to use ‘[’KEY‘]+=’VALUE to append to the existing value
at that key.  Expansion is performed identically to the corresponding
forms for normal arrays, as described above.

To create an empty array (including associative arrays), use one of:

     ‘set -A’ NAME

     NAME‘=()’

* Menu:

* Array Subscripts::
* Array Element Assignment::
* Subscript Flags::
* Subscript Parsing::


File: zsh.info,  Node: Array Subscripts,  Next: Array Element Assignment,  Up: Array Parameters

14.2.1 Array Subscripts
-----------------------

Individual elements of an array may be selected using a subscript.  A
subscript of the form ‘[’EXP‘]’ selects the single element EXP, where
EXP is an arithmetic expression which will be subject to arithmetic
expansion as if it were surrounded by ‘$((...))’.  The elements are
numbered beginning with 1, unless the ‘KSH_ARRAYS’ option is set in
which case they are numbered from zero.  ..  index:: single: KSH_ARRAYS,
use of; Program

Subscripts may be used inside braces used to delimit a parameter name,
thus ‘${foo[2]}’ is equivalent to ‘$foo[2]’.  If the ‘KSH_ARRAYS’ option
is set, the braced form is the only one that works, as bracketed
expressions otherwise are not treated as subscripts.

If the ‘KSH_ARRAYS’ option is not set, then by default accesses to an
array element with a subscript that evaluates to zero return an empty
string, while an attempt to write such an element is treated as an
error.  For backward compatibility the ‘KSH_ZERO_SUBSCRIPT’ option can
be set to cause subscript values 0 and 1 to be equivalent; see the
description of the option in ‘zshoptions’.

The same subscripting syntax is used for associative arrays, except that
no arithmetic expansion is applied to EXP.  However, the parsing rules
for arithmetic expressions still apply, which affects the way that
certain special characters must be protected from interpretation.  See
‘Subscript Parsing’ below for details.

A subscript of the form ‘[*]’ or ‘[@]’ evaluates to all elements of an
array; there is no difference between the two except when they appear
within double quotes.  ‘"$foo[*]"’ evaluates to ‘"$foo[1] $foo[2] ..."’,
whereas ‘"$foo[@]"’ evaluates to ‘"$foo[1]" "$foo[2]"’ ….  For
associative arrays, ‘[*]’ or ‘[@]’ evaluate to all the values, in no
particular order.  Note that this does not substitute the keys; see the
documentation for the ‘k’ flag under *note Parameter Expansion Flags:
6e. for complete details.  When an array parameter is referenced as
‘$’NAME (with no subscript) it evaluates to ‘$’NAME‘[*]’, unless the
‘KSH_ARRAYS’ option is set in which case it evaluates to ‘${’NAME‘[0]}’
(for an associative array, this means the value of the key ‘0’, which
may not exist even if there are values for other keys).

A subscript of the form ‘[’EXP1‘,’EXP2‘]’ selects all elements in the
range EXP1 to EXP2, inclusive.  (Associative arrays are unordered, and
so do not support ranges.)  If one of the subscripts evaluates to a
negative number, say ‘-’N, then the Nth element from the end of the
array is used.  Thus ‘$foo[-3]’ is the third element from the end of the
array ‘foo’, and ‘$foo[1,-1]’ is the same as ‘$foo[*]’.

Subscripting may also be performed on non-array values, in which case
the subscripts specify a substring to be extracted.  For example, if
‘FOO’ is set to ‘foobar’, then ‘echo $FOO[2,5]’ prints ‘ooba’.  Note
that some forms of subscripting described below perform pattern
matching, and in that case the substring extends from the start of the
match of the first subscript to the end of the match of the second
subscript.  For example,

      string="abcdefghijklm"
      print ${string[(r)d?,(r)h?]}

prints ‘defghi’.  This is an obvious generalisation of the rule for
single-character matches.  For a single subscript, only a single
character is referenced (not the range of characters covered by the
match).

Note that in substring operations the second subscript is handled
differently by the ‘r’ and ‘R’ subscript flags: the former takes the
shortest match as the length and the latter the longest match.  Hence in
the former case a ‘*’ at the end is redundant while in the latter case
it matches the whole remainder of the string.  This does not affect the
result of the single subscript case as here the length of the match is
irrelevant.


File: zsh.info,  Node: Array Element Assignment,  Next: Subscript Flags,  Prev: Array Subscripts,  Up: Array Parameters

14.2.2 Array Element Assignment
-------------------------------

A subscript may be used on the left side of an assignment like so:

     NAME‘[’EXP‘]=’VALUE

In this form of assignment the element or range specified by EXP is
replaced by the expression on the right side.  An array (but not an
associative array) may be created by assignment to a range or element.
Arrays do not nest, so assigning a parenthesized list of values to an
element or range changes the number of elements in the array, shifting
the other elements to accommodate the new values.  (This is not
supported for associative arrays.)

This syntax also works as an argument to the ‘typeset’ command:

     ‘typeset’ ‘"’NAME‘[’EXP‘]"=’VALUE

The VALUE may ‘not’ be a parenthesized list in this case; only
single-element assignments may be made with ‘typeset’.  Note that quotes
are necessary in this case to prevent the brackets from being
interpreted as filename generation operators.  The ‘noglob’ precommand
modifier could be used instead.

To delete an element of an ordinary array, assign ‘()’ to that element.
To delete an element of an associative array, use the ‘unset’ command:

     ‘unset’ ‘"’NAME‘[’EXP‘]"’


File: zsh.info,  Node: Subscript Flags,  Next: Subscript Parsing,  Prev: Array Element Assignment,  Up: Array Parameters

14.2.3 Subscript Flags
----------------------

If the opening bracket, or the comma in a range, in any subscript
expression is directly followed by an opening parenthesis, the string up
to the matching closing one is considered to be a list of flags, as in
NAME‘[(’FLAGS‘)’EXP‘]’.

The flags ‘s’, ‘n’ and ‘b’ take an argument; the delimiter is shown
below as ‘:’, but any character, or the matching pairs ‘(...)’, ‘{...}’,
‘[...]’, or ‘<...>’, may be used, but note that ‘<...>’ can only be used
if the subscript is inside a double quoted expression or a parameter
substitution enclosed in braces as otherwise the expression is
interpreted as a redirection.

The flags currently understood are:

‘w’

     If the parameter subscripted is a scalar then this flag makes
     subscripting work on words instead of characters.  The default word
     separator is whitespace.  When combined with the ‘i’ or ‘I’ flag,
     the effect is to produce the index of the first character of the
     first/last word which matches the given pattern; note that a failed
     match in this case always yields 0.

‘s:’STRING‘:’

     This gives the STRING that separates words (for use with the ‘w’
     flag).  The delimiter character ‘:’ is arbitrary; see above.

‘p’

     Recognize the same escape sequences as the ‘print’ builtin in the
     string argument of a subsequent ‘s’ flag.

‘f’

     If the parameter subscripted is a scalar then this flag makes
     subscripting work on lines instead of characters, i.e.  with
     elements separated by newlines.  This is a shorthand for ‘pws:\n:’.

‘r’

     Reverse subscripting: if this flag is given, the EXP is taken as a
     pattern and the result is the first matching array element,
     substring or word (if the parameter is an array, if it is a scalar,
     or if it is a scalar and the ‘w’ flag is given, respectively).  The
     subscript used is the number of the matching element, so that pairs
     of subscripts such as ‘$foo[(r)??,3]’ and ‘$foo[(r)??,(r)f*]’ are
     possible if the parameter is not an associative array.  If the
     parameter is an associative array, only the value part of each pair
     is compared to the pattern, and the result is that value.

     If a search through an ordinary array failed, the search sets the
     subscript to one past the end of the array, and hence
     ‘${array[(r)’PATTERN‘]}’ will substitute the empty string.  Thus
     the success of a search can be tested by using the ‘(i)’ flag, for
     example (assuming the option ‘KSH_ARRAYS’ is not in effect):

           [[ ${array[(i)pattern]} -le ${#array} ]]

     If ‘KSH_ARRAYS’ is in effect, the ‘-le’ should be replaced by
     ‘-lt’.

‘R’

     Like ‘r’, but gives the last match.  For associative arrays, gives
     all possible matches.  May be used for assigning to ordinary array
     elements, but not for assigning to associative arrays.  On failure,
     for normal arrays this has the effect of returning the element
     corresponding to subscript 0; this is empty unless one of the
     options ‘KSH_ARRAYS’ or ‘KSH_ZERO_SUBSCRIPT’ is in effect.

     Note that in subscripts with both ‘r’ and ‘R’ pattern characters
     are active even if they were substituted for a parameter
     (regardless of the setting of ‘GLOB_SUBST’ which controls this
     feature in normal pattern matching).  The flag ‘e’ can be added to
     inhibit pattern matching.  As this flag does not inhibit other
     forms of substitution, care is still required; using a parameter to
     hold the key has the desired effect:

           key2='original key'
           print ${array[(Re)$key2]}

‘i’

     Like ‘r’, but gives the index of the match instead; this may not be
     combined with a second argument.  On the left side of an
     assignment, behaves like ‘r’.  For associative arrays, the key part
     of each pair is compared to the pattern, and the first matching key
     found is the result.  On failure substitutes the length of the
     array plus one, as discussed under the description of ‘r’, or the
     empty string for an associative array.

     Note: Although ‘i’ may be applied to a scalar substitution to find
     the offset of a substring, the results are likely to be misleading
     when searching within substitutions that yield an empty string, or
     when searching for the empty substring.

‘I’

     Like ‘i’, but gives the index of the last match, or all possible
     matching keys in an associative array.  On failure substitutes 0,
     or the empty string for an associative array.  This flag is best
     when testing for values or keys that do not exist.

     Note: If the option ‘KSH_ARRAYS’ is in effect and no match is
     found, the result is indistinguishable from the case when the first
     element of the array matches.

‘k’

     If used in a subscript on an associative array, this flag causes
     the keys to be interpreted as patterns, and returns the value for
     the first key found where EXP is matched by the key.  Note this
     could be any such key as no ordering of associative arrays is
     defined.  This flag does not work on the left side of an assignment
     to an associative array element.  If used on another type of
     parameter, this behaves like ‘r’.

‘K’

     On an associative array this is like ‘k’ but returns all values
     where EXP is matched by the keys.  On other types of parameters
     this has the same effect as ‘R’.

‘n:’EXPR‘:’

     If combined with ‘r’, ‘R’, ‘i’ or ‘I’, makes them give the Nth or
     Nth last match (if EXPR evaluates to N).  This flag is ignored when
     the array is associative.  The delimiter character ‘:’ is
     arbitrary; see above.

‘b:’EXPR‘:’

     If combined with ‘r’, ‘R’, ‘i’ or ‘I’, makes them begin at the Nth
     or Nth last element, word, or character (if EXPR evaluates to N).
     This flag is ignored when the array is associative.  The delimiter
     character ‘:’ is arbitrary; see above.

‘e’

     This flag causes any pattern matching that would be performed on
     the subscript to use plain string matching instead.  Hence
     ‘${array[(re)*]}’ matches only the array element whose value is
     ‘*’.  Note that other forms of substitution such as parameter
     substitution are not inhibited.

     This flag can also be used to force ‘*’ or ‘@’ to be interpreted as
     a single key rather than as a reference to all values.  It may be
     used for either purpose on the left side of an assignment.

See *note Parameter Expansion Flags: 6e. for additional ways to
manipulate the results of array subscripting.


File: zsh.info,  Node: Subscript Parsing,  Prev: Subscript Flags,  Up: Array Parameters

14.2.4 Subscript Parsing
------------------------

This discussion applies mainly to associative array key strings and to
patterns used for reverse subscripting (the ‘r’, ‘R’, ‘i’, etc.  flags),
but it may also affect parameter substitutions that appear as part of an
arithmetic expression in an ordinary subscript.

To avoid subscript parsing limitations in assignments to associative
array elements, use the append syntax:

      aa+=('key with "*strange*" characters' 'value string')

The basic rule to remember when writing a subscript expression is that
all text between the opening ‘[’ and the closing ‘]’ is interpreted ‘as
if’ it were in double quotes (see *note Quoting: 8f.).  However, unlike
double quotes which normally cannot nest, subscript expressions may
appear inside double-quoted strings or inside other subscript
expressions (or both!), so the rules have two important differences.

The first difference is that brackets (‘[’ and ‘]’) must appear as
balanced pairs in a subscript expression unless they are preceded by a
backslash (‘\’).  Therefore, within a subscript expression (and unlike
true double-quoting) the sequence ‘\[’ becomes ‘[’, and similarly ‘\]’
becomes ‘]’.  This applies even in cases where a backslash is not
normally required; for example, the pattern ‘[^[]’ (to match any
character other than an open bracket) should be written ‘[^\[]’ in a
reverse-subscript pattern.  However, note that ‘\[^\[\]’ and even
‘\[^[]’ mean the ‘same’ thing, because backslashes are always stripped
when they appear before brackets!

The same rule applies to parentheses (‘(’ and ‘)’) and braces (‘{’ and
‘}’): they must appear either in balanced pairs or preceded by a
backslash, and backslashes that protect parentheses or braces are
removed during parsing.  This is because parameter expansions may be
surrounded by balanced braces, and subscript flags are introduced by
balanced parentheses.

The second difference is that a double-quote (‘"’) may appear as part of
a subscript expression without being preceded by a backslash, and
therefore that the two characters ‘\"’ remain as two characters in the
subscript (in true double-quoting, ‘\"’ becomes ‘"’).  However, because
of the standard shell quoting rules, any double-quotes that appear must
occur in balanced pairs unless preceded by a backslash.  This makes it
more difficult to write a subscript expression that contains an odd
number of double-quote characters, but the reason for this difference is
so that when a subscript expression appears inside true double-quotes,
one can still write ‘\"’ (rather than ‘\\\"’) for ‘"’.

To use an odd number of double quotes as a key in an assignment, use the
‘typeset’ builtin and an enclosing pair of double quotes; to refer to
the value of that key, again use double quotes:

      typeset -A aa
      typeset "aa[one\"two\"three\"quotes]"=QQQ
      print "$aa[one\"two\"three\"quotes]"

It is important to note that the quoting rules do not change when a
parameter expansion with a subscript is nested inside another subscript
expression.  That is, it is not necessary to use additional backslashes
within the inner subscript expression; they are removed only once, from
the innermost subscript outwards.  Parameters are also expanded from the
innermost subscript first, as each expansion is encountered left to
right in the outer expression.

A further complication arises from a way in which subscript parsing is
‘not’ different from double quote parsing.  As in true double-quoting,
the sequences ‘\*’, and ‘\@’ remain as two characters when they appear
in a subscript expression.  To use a literal ‘*’ or ‘@’ as an
associative array key, the ‘e’ flag must be used:

      typeset -A aa
      aa[(e)*]=star
      print $aa[(e)*]

A last detail must be considered when reverse subscripting is performed.
Parameters appearing in the subscript expression are first expanded and
then the complete expression is interpreted as a pattern.  This has two
effects: first, parameters behave as if ‘GLOB_SUBST’ were on (and it
cannot be turned off); second, backslashes are interpreted twice, once
when parsing the array subscript and again when parsing the pattern.  In
a reverse subscript, it’s necessary to use ‘four’ backslashes to cause a
single backslash to match literally in the pattern.  For complex
patterns, it is often easiest to assign the desired pattern to a
parameter and then refer to that parameter in the subscript, because
then the backslashes, brackets, parentheses, etc., are seen only when
the complete expression is converted to a pattern.  To match the value
of a parameter literally in a reverse subscript, rather than as a
pattern, use ‘${(q)’NAME‘}’ (*note Parameter Expansion: 1a.) to quote
the expanded value.

Note that the ‘k’ and ‘K’ flags are reverse subscripting for an ordinary
array, but are ‘not’ reverse subscripting for an associative array!
(For an associative array, the keys in the array itself are interpreted
as patterns by those flags; the subscript is a plain string in that
case.)

One final note, not directly related to subscripting: the numeric names
of positional parameters ( ..  only:: man

     described below

Positional Parameters

) are parsed specially, so for example ‘$2foo’ is equivalent to
‘${2}foo’.  Therefore, to use subscript syntax to extract a substring
from a positional parameter, the expansion must be surrounded by braces;
for example, ‘${2[3,5]}’ evaluates to the third through fifth characters
of the second positional parameter, but ‘$2[3,5]’ is the entire second
parameter concatenated with the filename generation pattern ‘[3,5]’.


File: zsh.info,  Node: Positional Parameters,  Next: Local Parameters,  Prev: Array Parameters,  Up: Parameters

14.3 Positional Parameters
==========================

The positional parameters provide access to the command-line arguments
of a shell function, shell script, or the shell itself; see *note
Invocation: 91, and also *note Functions: 92.  The parameter N, where N
is a number, is the Nth positional parameter.  The parameter ‘$0’ is a
special case, see *note Parameters Set by the Shell: 93.

The parameters ‘*’, ‘@’ and ‘argv’ are arrays containing all the
positional parameters; thus ‘$argv[’N‘]’, etc., is equivalent to simply
‘$’N.  Note that the options ‘KSH_ARRAYS’ or ‘KSH_ZERO_SUBSCRIPT’ apply
to these arrays as well, so with either of those options set,
‘${argv[0]}’ is equivalent to ‘$1’ and so on.

Positional parameters may be changed after the shell or function starts
by using the ‘set’ builtin, by assigning to the ‘argv’ array, or by
direct assignment of the form N‘=’VALUE where N is the number of the
positional parameter to be changed.  This also creates (with empty
values) any of the positions from 1 to N that do not already have
values.  Note that, because the positional parameters form an array, an
array assignment of the form N‘=(’VALUE …‘‘)‘‘ is allowed, and has the
effect of shifting all the values at positions greater than N by as many
positions as necessary to accommodate the new values.


File: zsh.info,  Node: Local Parameters,  Next: Named References<2>,  Prev: Positional Parameters,  Up: Parameters

14.4 Local Parameters
=====================

Shell function executions delimit scopes for shell parameters.
(Parameters are dynamically scoped.)  The ‘typeset’ builtin, and its
alternative forms ‘declare’, ‘integer’, ‘local’ and ‘readonly’ (but not
‘export’), can be used to declare a parameter as being local to the
innermost scope.

When a parameter is read or assigned to, the innermost existing
parameter of that name is used.  (That is, the local parameter hides any
less-local parameter.)  However, assigning to a non-existent parameter,
or declaring a new parameter with ‘export’, causes it to be created in
the ‘outer’most scope.

Local parameters disappear when their scope ends.  ‘unset’ can be used
to delete a parameter while it is still in scope; any outer parameter of
the same name remains hidden.

Special parameters may also be made local; they retain their special
attributes unless either the existing or the newly-created parameter has
the ‘-h’ (hide) attribute.  This may have unexpected effects: there is
no default value, so if there is no assignment at the point the variable
is made local, it will be set to an empty value (or zero in the case of
integers).  The following:

      typeset PATH=/new/directory:$PATH

is valid for temporarily allowing the shell or programmes called from it
to find the programs in ‘/new/directory’ inside a function.

Note that the restriction in older versions of zsh that local parameters
were never exported has been removed.


File: zsh.info,  Node: Named References<2>,  Next: Parameters Set by the Shell,  Prev: Local Parameters,  Up: Parameters

14.5 Named References
=====================

Zsh supports two different mechanisms for indirect parameter
referencing:

      typeset NAME=RNAME
      print -r -- ${(P)NAME}

      typeset -n PNAME=RNAME
      print -r -- ${PNAME}

The ‘(P)’ flag method is older and should be used when a script needs to
be backwards-compatible.  This is described fully in *note Parameter
Expansion Flags: 6e.  Zsh versions ‘greater than’ ‘5.9.0’ are required
for ‘typeset -n’.  This manual was generated with Zsh ‘|release|’ .

When a ‘named reference’ is created with ‘typeset -n’, all uses of PNAME
in assignments and expansions instead assign to or expand RNAME.  This
also applies to ‘unset’ PNAME and to most subsequent uses of ‘typeset’
with the exceptions of declaring a local in a called function, or
updating a current-scope parameter with ‘typeset -n’ or ‘typeset +n’.
Thus to remove a named reference, use either ‘unset -n’ PNAME
(preferred) or one of:

      typeset -n PNAME=
      typeset +n PNAME

followed by

     ‘unset’ PNAME

An empty reference such as one of

      typeset -n PNAME
      typeset -n PNAME=

acts as a placeholder.  The first non-empty assignment to PNAME
initializes the reference, and subsequently any expansions of, or
assignments to, PNAME act on the referenced parameter.  This is
explained in *note Named References: 70.

A placeholder PNAME in a calling function may be initialized in a called
function to reference a local parameter RNAME.  In this case, when the
called function returns, PNAME is no longer associated with that local.
However, the initializer RNAME continues to be substituted when ‘$’PNAME
is used, and therefore may become a reference to another parameter in
the calling function.  It is recommended that placeholders be
initialized soon after they are declared, to make it clear what they
reference.


File: zsh.info,  Node: Parameters Set by the Shell,  Next: Parameters Used by the Shell,  Prev: Named References<2>,  Up: Parameters

14.6 Parameters Set by the Shell
================================

In the parameter lists that follow, the mark ‘<S>’ indicates that the
parameter is special.  ‘<Z>’ indicates that the parameter does not exist
when the shell initializes in ‘sh’ or ‘ksh’ emulation mode.

The parameters ‘!’, ‘#’, ‘*’, ‘-’, ‘?’, ‘@’, ‘$’, ‘ARGC’, ‘HISTCMD’,
‘LINENO’, ‘PPID’, ‘status’, ‘TTYIDLE’, ‘zsh_eval_context’,
‘ZSH_EVAL_CONTEXT’, and ‘ZSH_SUBSHELL’ are read-only and thus cannot be
restored by the user, so they are not output by ‘typeset -p’.  This also
applies to many read-only parameters loaded from modules.

The following parameters are automatically set by the shell:

‘!’ <S>

     The process ID of the last command started in the background with
     ‘&’, put into the background with the ‘bg’ builtin, or spawned with
     ‘coproc’.

‘#’ <S>

     The number of positional parameters in decimal.  Note that some
     confusion may occur with the syntax ‘$#’PARAM which substitutes the
     length of PARAM.  Use ‘${#}’ to resolve ambiguities.  In
     particular, the sequence ‘$#-’… in an arithmetic expression is
     interpreted as the length of the parameter ‘-’, q.v.

‘ARGC’ <S> <Z>

     Same as ‘#’.

‘$’ <S>

     The process ID of this shell, set when the shell initializes.
     Processes forked from the shell without executing a new program,
     such as command substitutions and commands grouped with ‘(’…‘)’,
     are subshells that duplicate the current shell, and thus substitute
     the same value for ‘$$’ as their parent shell.

‘-’ <S>

     Flags supplied to the shell on invocation or by the ‘set’ or
     ‘setopt’ commands.

‘*’ <S>

     An array containing the positional parameters.

‘argv’ <S> <Z>

     Same as ‘*’.  Assigning to ‘argv’ changes the local positional
     parameters, but ‘argv’ is ‘not’ itself a local parameter.  Deleting
     ‘argv’ with ‘unset’ in any function deletes it everywhere.  This
     can be avoided by declaring ‘local +h argv’ before unsetting.  Even
     when not so declared, only the innermost positional parameter array
     is deleted (so ‘*’ and ‘@’ in other scopes are not affected).

     A named reference to ‘argv’ ‘does not’ permit a called function to
     access the positional parameters of its caller.

‘@’ <S>

     Same as ‘argv[@]’, even when ‘argv’ is not set.

‘?’ <S>

     The exit status returned by the last command.

‘0’ <S>

     The name used to invoke the current shell, or as set by the ‘-c’
     command line option upon invocation.  If the ‘FUNCTION_ARGZERO’
     option is set, ‘$0’ is set upon entry to a shell function to the
     name of the function, and upon entry to a sourced script to the
     name of the script, and reset to its previous value when the
     function or script returns.

‘status’ <S> <Z>

     Same as ‘?’.

‘pipestatus’ <S> <Z>

     An array containing the exit statuses returned by all commands in
     the last pipeline.

‘_’ <S>

     Initially, if ‘_’ exists in the environment, then this parameter is
     set to its value.  This value may be the full pathname of the
     current zsh executable or the script command file.  Later, this
     parameter is set to the last argument of the previous command.
     Also, this parameter is set in the environment of every command
     executed to the full pathname of the command.

‘CPUTYPE’

     The machine type (microprocessor class or machine model), as
     determined at run time.

‘EGID’ <S>

     The effective group ID of the shell process.  If you have
     sufficient privileges, you may change the effective group ID of the
     shell process by assigning to this parameter.  Also (assuming
     sufficient privileges), you may start a single command with a
     different effective group ID by ‘(EGID=’GID‘; command)’

     If this is made local, it is not implicitly set to 0, but may be
     explicitly set locally.

‘EUID’ <S>

     The effective user ID of the shell process.  If you have sufficient
     privileges, you may change the effective user ID of the shell
     process by assigning to this parameter.  Also (assuming sufficient
     privileges), you may start a single command with a different
     effective user ID by ‘(EUID=’UID‘; command)’

     If this is made local, it is not implicitly set to 0, but may be
     explicitly set locally.

‘ERRNO’ <S>

     The value of ‘errno’ (see ‘errno(3)’) as set by the most recently
     failed system call.  This value is system dependent and is intended
     for debugging purposes.  It is also useful with the ‘zsh/system’
     module which allows the number to be turned into a name or message.

     To use this parameter, it must first be assigned a value (typically
     0 (zero)).  It is initially unset for scripting compatibility.

‘FUNCNEST’ <S>

     Integer.  If greater than or equal to zero, the maximum nesting
     depth of shell functions.  When it is exceeded, an error is raised
     at the point where a function is called.  The default value is
     determined when the shell is configured, but is typically 500.
     Increasing the value increases the danger of a runaway function
     recursion causing the shell to crash.  Setting a negative value
     turns off the check.

‘GID’ <S>

     The real group ID of the shell process.  If you have sufficient
     privileges, you may change the group ID of the shell process by
     assigning to this parameter.  Also (assuming sufficient
     privileges), you may start a single command under a different group
     ID by ‘(GID=’GID‘; command)’

     If this is made local, it is not implicitly set to 0, but may be
     explicitly set locally.

‘HISTCMD’

     The current history event number in an interactive shell, in other
     words the event number for the command that caused ‘$HISTCMD’ to be
     read.  If the current history event modifies the history, ‘HISTCMD’
     changes to the new maximum history event number.

‘HOST’

     The current hostname.

‘LINENO’ <S>

     The line number of the current line within the current script,
     sourced file, or shell function being executed, whichever was
     started most recently.  Note that in the case of shell functions
     the line number refers to the function as it appeared in the
     original definition, not necessarily as displayed by the
     ‘functions’ builtin.

‘LOGNAME’

     If the corresponding variable is not set in the environment of the
     shell, it is initialized to the login name corresponding to the
     current login session.  This parameter is exported by default but
     this can be disabled using the ‘typeset’ builtin.  The value is set
     to the string returned by the ‘getlogin(3)’ system call if that is
     available.

‘MACHTYPE’

     The machine type (microprocessor class or machine model), as
     determined at compile time.

‘OLDPWD’

     The previous working directory.  This is set when the shell
     initializes and whenever the directory changes.

‘OPTARG’ <S>

     The value of the last option argument processed by the ‘getopts’
     command.

‘OPTIND’ <S>

     The index of the last option argument processed by the ‘getopts’
     command.

‘OSTYPE’

     The operating system, as determined at compile time.

‘PPID’ <S>

     The process ID of the parent of the shell, set when the shell
     initializes.  As with ‘$$’, the value does not change in subshells
     created as a duplicate of the current shell.

‘PWD’

     The present working directory.  This is set when the shell
     initializes and whenever the directory changes.

‘RANDOM’ <S>

     A pseudo-random integer from 0 to 32767, newly generated each time
     this parameter is referenced.  The random number generator can be
     seeded by assigning a numeric value to ‘RANDOM’.

     The values of ‘RANDOM’ form an intentionally-repeatable
     pseudo-random sequence; subshells that reference ‘RANDOM’ will
     result in identical pseudo-random values unless the value of
     ‘RANDOM’ is referenced or seeded in the parent shell in between
     subshell invocations.

     ‘RANDOM’ uses the system’s library function ‘rand(3)’.  If higher
     degree of randomness is required, please consider using the
     autoloadable parameter ‘SRANDOM’ from

     *note The zsh/random Module: 94.

     .

‘SECONDS’ <S>

     The number of seconds since shell invocation.  On most platforms,
     this is a monotonic value, so it is not affected by NTP time jumps
     or other clock changes (though it may be affected by slewing).  If
     this parameter is assigned a value, then the value returned upon
     reference will be the value that was assigned plus the number of
     seconds since the assignment.

     Unlike other special parameters, the type of the ‘SECONDS’
     parameter can be changed using the ‘typeset’ command.  The type may
     be changed only to one of the floating point types or back to
     integer.  For example, ‘typeset -F SECONDS’ causes the value to be
     reported as a floating point number.  The value is nominally
     available to nanosecond precision, although this varies by platform
     (and probably isn’t accurate to 1 ns regardless), and the shell may
     show more or fewer digits depending on the use of ‘typeset’.  See
     the documentation for the builtin ‘typeset’ in ‘zshbuiltins’ for
     more details.

‘SHLVL’ <S>

     Incremented by one each time a new shell is started.

‘signals’

     An array containing the names of the signals.  Note that with the
     standard zsh numbering of array indices, where the first element
     has index 1, the signals are offset by 1 from the signal number
     used by the operating system.  For example, on typical Unix-like
     systems ‘HUP’ is signal number 1, but is referred to as
     ‘$signals[2]’.  This is because of ‘EXIT’ at position 1 in the
     array, which is used internally by zsh but is not known to the
     operating system.  On many systems there is a block of reserved or
     unused signal numbers before the POSIX real-time signals so the
     array index can’t be used as an accurate indicator of their signal
     number.  Use, for example, ‘kill -l SIGRTMIN’ instead.

‘.term.cursor’

     The default color of the cursor.

     See also the ‘.term.extensions’ parameter.

‘.term.bg’

     The background color of the terminal if the terminal supports the
     necessary interface for retrieving this information.

     See also the ‘.term.extensions’ parameter.

‘.term.fg’

     Like ‘.term.bg’ but for the foreground color.

‘.term.id’

     Like the ‘TERM’ parameter, this identifies the terminal but is
     obtained by querying the terminal.  Many terminals name a different
     common terminal in ‘TERM’ that they then emulate, often
     imperfectly.  This allows them to work without the need to
     distribute updates to terminal capability databases.  The more
     accurate identification in this parameter may be useful when
     configuring aspects of the shell differently for specific
     terminals.

     See also the ‘.term.extensions’ parameter.

‘.term.version’

     The version number of the terminal application, set in conjunction
     with ‘.term.id’.

‘.term.mode’

     Either ‘light’ or ‘dark’.  In cases where the terminal background
     color is detected and set in ‘.term.bg’, this is set to provide a
     basic indication of how light that color is.  This may help with
     configuring readable color combinations.

‘TRY_BLOCK_ERROR’ <S>

     In an ‘always’ block, indicates whether the preceding list of code
     caused an error.  The value is 1 to indicate an error, 0 otherwise.
     It may be reset, clearing the error condition.  See *note Complex
     Commands: 95.

‘TRY_BLOCK_INTERRUPT’ <S>

     This variable works in a similar way to ‘TRY_BLOCK_ERROR’, but
     represents the status of an interrupt from the signal SIGINT, which
     typically comes from the keyboard when the user types ‘^C’.  If set
     to 0, any such interrupt will be reset; otherwise, the interrupt is
     propagated after the ‘always’ block.

     Note that it is possible that an interrupt arrives during the
     execution of the ‘always’ block; this interrupt is also propagated.

‘TTY’

     The name of the tty associated with the shell, if any.

‘TTYIDLE’ <S>

     The idle time of the tty associated with the shell in seconds or -1
     if there is no such tty.

‘UID’ <S>

     The real user ID of the shell process.  If you have sufficient
     privileges, you may change the user ID of the shell by assigning to
     this parameter.  Also (assuming sufficient privileges), you may
     start a single command under a different user ID by ‘(UID=’UID‘;
     command)’

     If this is made local, it is not implicitly set to 0, but may be
     explicitly set locally.

‘USERNAME’ <S>

     The username corresponding to the real user ID of the shell
     process.  If you have sufficient privileges, you may change the
     username (and also the user ID and group ID) of the shell by
     assigning to this parameter.  Also (assuming sufficient
     privileges), you may start a single command under a different
     username (and user ID and group ID) by ‘(USERNAME=’USERNAME‘;
     command)’

‘VENDOR’

     The vendor, as determined at compile time.

‘zsh_eval_context’ <S> <Z> (‘ZSH_EVAL_CONTEXT’ <S>)

     An array (colon-separated list) indicating the context of shell
     code that is being run.  Each time a piece of shell code that is
     stored within the shell is executed a string is temporarily
     appended to the array to indicate the type of operation that is
     being performed.  Read in order the array gives an indication of
     the stack of operations being performed with the most immediate
     context last.

     Note that the variable does not give information on syntactic
     context such as pipelines or subshells.  Use ‘$ZSH_SUBSHELL’ to
     detect subshells.

     The context is one of the following:

     ‘cmdarg’

          Code specified by the ‘-c’ option to the command line that
          invoked the shell.

     ‘cmdsubst’

          Command substitution using the >>‘‘<<‘\`:var:`...`\ ``’,
          ‘$(’…‘)’, ‘${{’NAME‘}’ …‘}’, ‘${|’…‘}’, or ‘${’ … ‘}’
          constructs.

     ‘equalsubst’

          The ‘=(’…‘)’ form of process substitution.

     ‘eval’

          Code executed by the ‘eval’ builtin.

     ‘evalautofunc’

          Code executed with the ‘KSH_AUTOLOAD’ mechanism in order to
          define an autoloaded function.

     ‘fc’

          Code from the shell history executed by the ‘-e’ option to the
          ‘fc’ builtin.

     ‘file’

          Lines of code being read directly from a file, for example by
          the ‘source’ builtin.

     ‘filecode’

          Lines of code being read from a ‘.zwc’ file instead of
          directly from the source file.

     ‘globqual’

          Code executed by the ‘e’ or ‘+’ glob qualifier.

     ‘globsort’

          Code executed to order files by the ‘o’ glob qualifier.

     ‘insubst’

          The ‘>(’…‘)’ form of process substitution.

     ‘loadautofunc’

          Code read directly from a file to define an autoloaded
          function.

     ‘math’

          Code executed in the ‘$((’…‘))’ or ‘((’…‘))’ constructs, by
          the ‘let’ builtin, in an array subscript, or in another
          arithmetic context.

     ‘outsubst’

          The ‘<(’…‘)’ form of process substitution.

     ‘sched’

          Code executed by the ‘sched’ builtin.

     ‘shfunc’

          A shell function.

     ‘stty’

          Code passed to ‘stty’ by the ‘STTY’ environment variable.
          Normally this is passed directly to the systems ‘stty’
          command, so this value is unlikely to be seen in practice.

     ‘style’

          Code executed as part of a style retrieved by the ‘zstyle’
          builtin from the ‘zsh/zutil’ module.

     ‘toplevel’

          The highest execution level of a script or interactive shell.

     ‘trap’

          Code executed as a trap defined by the ‘trap’ builtin.  Traps
          defined as functions have the context ‘shfunc’.  As traps are
          asynchronous they may have a different hierarchy from other
          code.

     ‘zpty’

          Code executed by the ‘zpty’ builtin from the ‘zsh/zpty’
          module.

     ‘zregexparse-guard’

          Code executed as a guard by the ‘zregexparse’ command from the
          ‘zsh/zutil’ module.

     ‘zregexparse-action’

          Code executed as an action by the ‘zregexparse’ command from
          the ‘zsh/zutil’ module.

‘ZSH_ARGZERO’

     If zsh was invoked to run a script, this is the name of the script.
     Otherwise, it is the name used to invoke the current shell.  This
     is the same as the value of ‘$0’ when the ‘POSIX_ARGZERO’ option is
     set, but is always available.

‘ZSH_EXECUTION_STRING’

     If the shell was started with the option ‘-c’, this contains the
     argument passed to the option.  Otherwise it is not set.

‘ZSH_EXEPATH’

     Full pathname of the executable file of the current zsh process.
     This value should be accurate on Linux, macOS, FreeBSD,
     DragonflyBSD, NetBSD, Solaris, Cygwin, and their derivatives.  On
     other systems, it is determined from ‘argv[0]’, which is not always
     accurate.

‘ZSH_NAME’

     Expands to the basename of the command used to invoke this instance
     of zsh.

‘ZSH_PATCHLEVEL’

     The output of ‘git describe --tags --long’ for the zsh repository
     used to build the shell.  This is most useful in order to keep
     track of versions of the shell during development between releases;
     hence most users should not use it and should instead rely on
     ‘$ZSH_VERSION’.

‘zsh_scheduled_events’

     See *note The zsh/sched Module: 96.

‘ZSH_SCRIPT’

     If zsh was invoked to run a script, this is the name of the script,
     otherwise it is unset.

‘ZSH_SUBSHELL’

     Readonly integer.  Initially zero, incremented each time the shell
     forks to create a subshell for executing code.  Hence ‘(print
     $ZSH_SUBSHELL)’ and ‘print $(print $ZSH_SUBSHELL)’ output 1, while
     ‘( (print $ZSH_SUBSHELL) )’ outputs 2.

‘ZSH_VERSION’

     The version number of the release of zsh.


File: zsh.info,  Node: Parameters Used by the Shell,  Prev: Parameters Set by the Shell,  Up: Parameters

14.7 Parameters Used by the Shell
=================================

The following parameters are used by the shell.  Again, ‘<S>’ indicates
that the parameter is special and ‘<Z>’ indicates that the parameter
does not exist when the shell initializes in ‘sh’ or ‘ksh’ emulation
mode.

In cases where there are two parameters with an upper- and lowercase
form of the same name, such as ‘path’ and ‘PATH’, the lowercase form is
an array and the uppercase form is a scalar with the elements of the
array joined together by colons.  These are similar to tied parameters
created via ‘typeset -T’.  The normal use for the colon-separated form
is for exporting to the environment, while the array form is easier to
manipulate within the shell.  Note that unsetting either of the pair
will unset the other; they retain their special properties when
recreated, and recreating one of the pair will recreate the other.

‘ARGV0’

     If exported, its value is used as the ‘argv[0]’ of external
     commands.  Usually used in constructs like ‘ARGV0=emacs nethack’.

‘BAUD’

     The rate in bits per second at which data reaches the terminal.
     The line editor will use this value in order to compensate for a
     slow terminal by delaying updates to the display until necessary.
     If the parameter is unset or the value is zero the compensation
     mechanism is turned off.  The parameter is not set by default.

     This parameter may be profitably set in some circumstances, e.g.
     for slow modems dialing into a communications server, or on a slow
     wide area network.  It should be set to the baud rate of the
     slowest part of the link for best performance.

‘cdpath’ <S> <Z> (‘CDPATH’ <S>)

     An array (colon-separated list) of directories specifying the
     search path for the ‘cd’ command.

‘COLUMNS’ <S>

     The number of columns for this terminal session.  Used for printing
     select lists and for the line editor.  If the shell is
     non-interactive and a legal value is imported from the environment,
     it is preserved.  Otherwise, the value is reset on start-up and in
     response to certain events such as the receipt of a ‘SIGWINCH’
     signal.  Explicitly setting it to an illegal value such as ‘0’ also
     resets it.  (Unsetting the parameter does not have this effect; it
     simply ‘hides’ the value that the shell is tracking internally.)

‘CORRECT_IGNORE’

     If set, is treated as a pattern during spelling correction.  Any
     potential correction that matches the pattern is ignored.  For
     example, if the value is ‘_*’ then completion functions (which, by
     convention, have names beginning with ‘_’) will never be offered as
     spelling corrections.  The pattern does not apply to the correction
     of file names, as applied by the ‘CORRECT_ALL’ option (so with the
     example just given files beginning with ‘_’ in the current
     directory would still be completed).

‘CORRECT_IGNORE_FILE’

     If set, is treated as a pattern during spelling correction of file
     names.  Any file name that matches the pattern is never offered as
     a correction.  For example, if the value is ‘.*’ then dot file
     names will never be offered as spelling corrections.  This is
     useful with the ‘CORRECT_ALL’ option.

‘DIRSTACKSIZE’

     The maximum size of the directory stack, by default there is no
     limit.  If the stack gets larger than this, it will be truncated
     automatically.  This is useful with the ‘AUTO_PUSHD’ option.  ..
     index:: single: AUTO_PUSHD, use of; Program

‘ENV’

     If the ‘ENV’ environment variable is set when zsh is invoked as
     ‘sh’ or ‘ksh’, ‘$ENV’ is sourced after the profile scripts.  The
     value of ‘ENV’ is subjected to parameter expansion, command
     substitution, and arithmetic expansion before being interpreted as
     a pathname.  Note that ‘ENV’ is ‘not’ used unless the shell is
     interactive and zsh is emulating ‘sh’ or ‘ksh’.

‘FCEDIT’

     The default editor for the ‘fc’ builtin.  If ‘FCEDIT’ is not set,
     the parameter ‘EDITOR’ is used; if that is not set either, a
     builtin default, usually ‘vi’, is used.

‘fignore’ <S> <Z> (‘FIGNORE’ <S>)

     An array (colon separated list) containing the suffixes of files to
     be ignored during filename completion.  However, if completion only
     generates files with suffixes in this list, then these files are
     completed anyway.

‘fpath’ <S> <Z> (‘FPATH’ <S>)

     An array (colon separated list) of directories specifying the
     search path for function definitions.  This path is searched when a
     function with the ‘-u’ attribute is referenced.  If an executable
     file is found, then it is read and executed in the current
     environment.

‘histchars’ <S>

     Three characters used by the shell’s history and lexical analysis
     mechanism.  The first character signals the start of a history
     expansion (default ‘!’).  The second character signals the start of
     a quick history substitution (default ‘^’).  The third character is
     the comment character (default ‘#’).

     The characters must be in the ASCII character set; any attempt to
     set ‘histchars’ to characters with a locale-dependent meaning will
     be rejected with an error message.

‘HISTCHARS’ <S> <Z>

     Same as ‘histchars’.  (Deprecated.)

‘HISTFILE’

     The file to save the history in when an interactive shell exits.
     If unset, the history is not saved.

‘HISTORY_IGNORE’

     If set, is treated as a pattern at the time history files are
     written.  Any potential history entry that matches the pattern is
     skipped.  For example, if the value is ‘fc *’ then commands that
     invoke the interactive history editor are never written to the
     history file.

     Note that ‘HISTORY_IGNORE’ defines a single pattern: to specify
     alternatives use the ‘(’FIRST‘|’SECOND‘|’…‘)’ syntax.

     Compare the ‘HIST_NO_STORE’ option or the ‘zshaddhistory’ hook,
     either of which would prevent such commands from being added to the
     interactive history at all.  If you wish to use ‘HISTORY_IGNORE’ to
     stop history being added in the first place, you can define the
     following hook:

           zshaddhistory() {
             emulate -L zsh
             ## uncomment if HISTORY_IGNORE
             ## should use EXTENDED_GLOB syntax
             # setopt extendedglob
             [[ $1 != ${~HISTORY_IGNORE} ]]
           }

‘HISTSIZE’ <S>

     The maximum number of events stored in the internal history list.
     If you use the ‘HIST_EXPIRE_DUPS_FIRST’ option, setting this value
     larger than the ‘SAVEHIST’ size will give you the difference as a
     cushion for saving duplicated history events.

     If this is made local, it is not implicitly set to 0, but may be
     explicitly set locally.

‘HOME’ <S>

     The default argument for the ‘cd’ command.  This is not set
     automatically by the shell in ‘sh’, ‘ksh’ or ‘csh’ emulation, but
     it is typically present in the environment anyway, and if it
     becomes set it has its usual special behaviour.

‘IFS’ <S>

     Internal field separators (by default space, tab, newline and NUL),
     that are used to separate words which result from command or
     parameter expansion and words read by the ‘read’ builtin.  Any
     characters from the set space, tab and newline that appear in the
     ‘IFS’ are called ‘IFS white space’.  One or more IFS white space
     characters or one non-IFS white space character together with any
     adjacent IFS white space character delimit a field.  If an IFS
     white space character appears twice consecutively in the ‘IFS’,
     this character is treated as if it were not an IFS white space
     character.

     If the parameter is unset, the default is used.  Note this has a
     different effect from setting the parameter to an empty string.

     If ‘MULTIBYTE’ option is on and ‘IFS’ contains invalid characters
     in the current locale, it is reset to the default.

‘KEYBOARD_HACK’

     This variable defines a character to be removed from the end of the
     command line before interpreting it (interactive shells only).  It
     is intended to fix the problem with keys placed annoyingly close to
     return and replaces the ‘SUNKEYBOARDHACK’ option which did this for
     backquotes only.  Should the chosen character be one of
     singlequote, doublequote or backquote, there must also be an odd
     number of them on the command line for the last one to be removed.

     For backward compatibility, if the ‘SUNKEYBOARDHACK’ option is
     explicitly set, the value of ‘KEYBOARD_HACK’ reverts to backquote.
     If the option is explicitly unset, this variable is set to empty.

‘KEYTIMEOUT’

     The time the shell waits, in hundredths of seconds, for another key
     to be pressed when reading bound multi-character sequences.

‘LANG’ <S>

     This variable determines the locale category for any category not
     specifically selected via a variable starting with ‘LC_’.

‘LC_ALL’ <S>

     This variable overrides the value of the ‘LANG’ variable and the
     value of any of the other variables starting with ‘LC_’.

‘LC_COLLATE’ <S>

     This variable determines the locale category for character
     collation information within ranges in glob brackets and for
     sorting.

‘LC_CTYPE’ <S>

     This variable determines the locale category for character handling
     functions.  If the ‘MULTIBYTE’ option is in effect this variable or
     ‘LANG’ should contain a value that reflects the character set in
     use, even if it is a single-byte character set, unless only the
     7-bit subset (ASCII) is used.  For example, if the character set is
     ISO-8859-1, a suitable value might be ‘en_US.iso88591’ (certain
     Linux distributions) or ‘en_US.ISO8859-1’ (MacOS).

‘LC_MESSAGES’ <S>

     This variable determines the language in which messages should be
     written.  Note that zsh does not use message catalogs.

‘LC_NUMERIC’ <S>

     This variable affects the decimal point character and thousands
     separator character for the formatted input/output functions and
     string conversion functions.  Note that zsh ignores this setting
     when parsing floating point mathematical expressions.

‘LC_TIME’ <S>

     This variable determines the locale category for date and time
     formatting in prompt escape sequences.

‘LINES’ <S>

     The number of lines for this terminal session.  Used for printing
     select lists and for the line editor.  See ‘COLUMNS’.

‘LISTMAX’

     In the line editor, the number of matches to list without asking
     first.  If the value is negative, the list will be shown if it
     spans at most as many lines as given by the absolute value.  If set
     to zero, the shell asks only if the top of the listing would scroll
     off the screen.

‘MAIL’

     If this parameter is set and ‘mailpath’ is not set, the shell looks
     for mail in the specified file.

‘MAILCHECK’

     The interval in seconds between checks for new mail.

‘mailpath’ <S> <Z> (‘MAILPATH’ <S>)

     An array (colon-separated list) of filenames to check for new mail.
     Each filename can be followed by a ‘?’ and a message that will be
     printed.  The message will undergo parameter expansion, command
     substitution and arithmetic expansion with the variable ‘$_’
     defined as the name of the file that has changed.  The default
     message is ‘You have new mail’.  If an element is a directory
     instead of a file the shell will recursively check every file in
     every subdirectory of the element.

‘manpath’ <S> <Z> (‘MANPATH’ <S> <Z>)

     An array (colon-separated list) whose value is not used by the
     shell.  The ‘manpath’ array can be useful, however, since setting
     it also sets ‘MANPATH’, and vice versa.

‘match’

‘mbegin’

‘mend’

     Arrays set by the shell when the ‘b’ globbing flag is used in
     pattern matches.  See *note Globbing Flags: 80.

‘MATCH’

‘MBEGIN’

‘MEND’

     Set by the shell when the ‘m’ globbing flag is used in pattern
     matches.  See *note Globbing Flags: 80.

‘module_path’ <S> <Z> (‘MODULE_PATH’ <S>)

     An array (colon-separated list) of directories that ‘zmodload’
     searches for dynamically loadable modules.  This is initialized to
     a standard pathname, usually ‘/usr/local/lib/zsh/$ZSH_VERSION’.
     (The ‘/usr/local/lib’ part varies from installation to
     installation.)  For security reasons, any value set in the
     environment when the shell is started will be ignored.

     These parameters only exist if the installation supports dynamic
     module loading.

‘NULLCMD’ <S>

     The command name to assume if a redirection is specified with no
     command.  Defaults to ‘cat’.  For ‘sh’/‘ksh’ behavior, change this
     to ‘:’.  For ‘csh’-like behavior, unset this parameter; the shell
     will print an error message if null commands are entered.

‘path’ <S> <Z> (‘PATH’ <S>)

     An array (colon-separated list) of directories to search for
     commands.  When this parameter is set, each directory is scanned
     and all files found are put in a hash table.  Directories named by
     relative path are not scanned for hashing.

‘POSTEDIT’ <S>

     This string is output whenever the line editor exits.  It usually
     contains termcap strings to reset the terminal.

‘PROMPT’ <S> <Z>

‘PROMPT2’ <S> <Z>

‘PROMPT3’ <S> <Z>

‘PROMPT4’ <S> <Z>

     Same as ‘PS1’, ‘PS2’, ‘PS3’ and ‘PS4’, respectively.

‘prompt’ <S> <Z>

     Same as ‘PS1’.

‘PROMPT_EOL_MARK’

     When the ‘PROMPT_CR’ and ‘PROMPT_SP’ options are set, the
     ‘PROMPT_EOL_MARK’ parameter can be used to customize how the end of
     partial lines are shown.  This parameter undergoes prompt
     expansion, with the ‘PROMPT_PERCENT’ option set.  If not set, the
     default behavior is equivalent to the value ‘%B%S%#%s%b’.

‘PS1’ <S>

     The primary prompt string, printed before a command is read.  It
     undergoes a special form of expansion before being displayed; see
     *note Expansion of Prompt Sequences: 97.  The default is ‘%m%#’ .

‘PS2’ <S>

     The secondary prompt, printed when the shell needs more information
     to complete a command.  It is expanded in the same way as ‘PS1’.
     The default is ‘%_>’ , which displays any shell constructs or
     quotation marks which are currently being processed.

‘PS3’ <S>

     Selection prompt used within a ‘select’ loop.  It is expanded in
     the same way as ‘PS1’.  The default is ‘?#’ .

‘PS4’ <S>

     The execution trace prompt.  Default is ‘+%N:%i>’ , which displays
     the name of the current shell structure and the line number within
     it.  In sh or ksh emulation, the default is ‘+’ .

‘psvar’ <S> <Z> (‘PSVAR’ <S>)

     An array (colon-separated list) whose elements can be used in
     ‘PROMPT’ strings.  Setting ‘psvar’ also sets ‘PSVAR’, and vice
     versa.

‘READNULLCMD’ <S>

     The command name to assume if a single input redirection is
     specified with no command.  Defaults to ‘more’.

‘REPORTMEMORY’

     If nonnegative, commands whose maximum resident set size (roughly
     speaking, main memory usage) in kilobytes is greater than this
     value have timing statistics reported.  The format used to output
     statistics is the value of the ‘TIMEFMT’ parameter, which is the
     same as for the ‘REPORTTIME’ variable and the ‘time’ builtin; note
     that by default this does not output memory usage.  Appending ‘"
     max RSS %M"’ to the value of ‘TIMEFMT’ causes it to output the
     value that triggered the report.  If ‘REPORTTIME’ is also in use,
     at most a single report is printed for both triggers.  This feature
     requires the ‘getrusage()’ system call, commonly supported by
     modern Unix-like systems.

‘REPORTTIME’

     If nonnegative, commands whose combined user and system execution
     times (measured in seconds) are greater than this value have timing
     statistics printed for them.  Output is suppressed for commands
     executed within the line editor, including completion; commands
     explicitly marked with the ‘time’ keyword still cause the summary
     to be printed in this case.

‘REPLY’

     This parameter is reserved by convention to pass string values
     between shell scripts and shell builtins in situations where a
     function call or redirection are impossible or undesirable.  The
     ‘read’ builtin and the ‘select’ complex command may set ‘REPLY’,
     and filename generation both sets and examines its value when
     evaluating certain expressions.  Some modules also employ ‘REPLY’
     for similar purposes.

‘reply’

     As ‘REPLY’, but for array values rather than strings.

‘RPROMPT’ <S>

‘RPS1’ <S>

     This prompt is displayed on the right-hand side of the screen when
     the primary prompt is being displayed on the left.  This does not
     work if the ‘SINGLE_LINE_ZLE’ option is set.  It is expanded in the
     same way as ‘PS1’.

‘RPROMPT2’ <S>

‘RPS2’ <S>

     This prompt is displayed on the right-hand side of the screen when
     the secondary prompt is being displayed on the left.  This does not
     work if the ‘SINGLE_LINE_ZLE’ option is set.  It is expanded in the
     same way as ‘PS2’.

‘SAVEHIST’

     The maximum number of history events to save in the history file.

     If this is made local, it is not implicitly set to 0, but may be
     explicitly set locally.

‘SPROMPT’ <S>

     The prompt used for spelling correction.  The sequence ‘%R’ expands
     to the string which presumably needs spelling correction, and ‘%r’
     expands to the proposed correction.  All other prompt escapes are
     also allowed.

     The actions available at the prompt are ‘[nyae]’:

     ‘n’ (‘no’) (default)

          Discard the correction.  If there are no more corrections,
          accept the command line, else (with ‘CORRECT_ALL’) prompt for
          the next.

     ‘y’ (‘yes’)

          Make the correction.  If there are no more corrections, accept
          the command line.

     ‘a’ (‘abort’)

          Place the entire command line in the history for later edit,
          but without accepting it.

     ‘e’ (‘edit’)

          Resume editing the command line.

‘STTY’

     If this parameter is set in a command’s environment, the shell runs
     the ‘stty’ command with the value of this parameter as arguments in
     order to set up the terminal before executing the command.  The
     modes apply only to the command, and are reset when it finishes or
     is suspended.  If the command is suspended and continued later with
     the ‘fg’ or ‘wait’ builtins it will see the modes specified by
     ‘STTY’, as if it were not suspended.  This (intentionally) does not
     apply if the command is continued via ‘kill -CONT’.‘‘ STTY‘‘ is
     ignored if the command is run in the background, or if it is in the
     environment of the shell but not explicitly assigned to in the
     input line.  This avoids running stty at every external command by
     accidentally exporting it.  Also note that ‘STTY’ should not be
     used for window size specifications; these will not be local to the
     command.

     If the parameter is set and empty, all of the above applies except
     that ‘stty’ is not run.  This can be useful as a way to freeze the
     tty around a single command, blocking its changes to tty settings,
     similar to the ‘ttyctl’ builtin.

‘TERM’ <S>

     The type of terminal in use.  This is used when looking up termcap
     sequences.  An assignment to ‘TERM’ causes zsh to re-initialize the
     terminal, even if the value does not change (e.g., ‘TERM=$TERM’).
     It is necessary to make such an assignment upon any change to the
     terminal definition database or terminal type in order for the new
     settings to take effect.

‘TERMINFO’ <S>

     A reference to your terminfo database, used by the ‘terminfo’
     library when the system has it; see ‘terminfo(5)’.  If set, this
     causes the shell to reinitialise the terminal, making the
     workaround ‘TERM=$TERM’ unnecessary.

‘TERMINFO_DIRS’ <S>

     A colon-seprarated list of terminfo databases, used by the
     ‘terminfo’ library when the system has it; see ‘terminfo(5)’.  This
     variable is only used by certain terminal libraries, in particular
     ncurses; see ‘terminfo(5)’ to check support on your system.  If
     set, this causes the shell to reinitialise the terminal, making the
     workaround ‘TERM=$TERM’ unnecessary.  Note that unlike other
     colon-separated arrays this is not tied to a zsh array.

‘.term.extensions’

     An array containing a list of extension features of the terminal.
     See *note Terminal Extensions: 98.

‘.term.querywait’

     The time the shell waits, in hundredths of seconds, for the
     response to terminal queries.  A value of ‘\`0'’ disables the
     timeout and the shell will wait indefinitely.  If not set, a
     default of ‘\`50'’ or half a second is used.

‘TIMEFMT’

     The format of process time reports with the ‘time’ keyword.  The
     default is ‘%J %U user %S system %P cpu %*E total’.  Recognizes the
     following escape sequences, although not all may be available on
     all systems, and some that are available may not be useful:

     ‘%%’

          A ‘%’.

     ‘%U’

          CPU seconds spent in user mode.

     ‘%S’

          CPU seconds spent in kernel mode.

     ‘%E’

          Elapsed time in seconds.

     ‘%P’

          The CPU percentage, computed as 100*(‘%U+%S)/%E’.

     ‘%W’

          Number of times the process was swapped.

     ‘%X’

          The average amount in (shared) text space used in kilobytes.

     ‘%D’

          The average amount in (unshared) data/stack space used in
          kilobytes.

     ‘%K’

          The total space used (‘%X+%D’) in kilobytes.

     ‘%M’

          The maximum memory the process had in use at any time in
          kilobytes.

     ‘%F’

          The number of major page faults (page needed to be brought
          from disk).

     ‘%R’

          The number of minor page faults.

     ‘%I’

          The number of input operations.

     ‘%O’

          The number of output operations.

     ‘%r’

          The number of socket messages received.

     ‘%s’

          The number of socket messages sent.

     ‘%k’

          The number of signals received.

     ‘%w’

          Number of voluntary context switches (waits).

     ‘%c’

          Number of involuntary context switches.

     ‘%J’

          The name of this job.

     A star may be inserted between the percent sign and flags printing
     time (e.g., ‘%*E’); this causes the time to be printed in
     HH‘:’MM‘:’SS‘.’TTT format (hours and minutes are only printed if
     they are not zero).  Alternatively, ‘m’, ‘u’, or ‘n’ may be used
     (e.g., ‘%mE’) to produce time output in milliseconds, microseconds,
     or nanoseconds, respectively.  Note that some timings on some
     platforms are not actually nanosecond-precise (nor accurate to 1 ns
     when they are); in fact on many systems user and kernel times are
     not even microsecond-precise.

‘TMOUT’

     If this parameter is nonzero, the shell will receive an ‘ALRM’
     signal if a command is not entered within the specified number of
     seconds after issuing a prompt.  If there is a trap on ‘SIGALRM’,
     it will be executed and a new alarm is scheduled using the value of
     the ‘TMOUT’ parameter after executing the trap.  If no trap is set,
     and the idle time of the terminal is not less than the value of the
     ‘TMOUT’ parameter, zsh terminates.  Otherwise a new alarm is
     scheduled to ‘TMOUT’ seconds after the last keypress.

‘TMPPREFIX’

     A pathname prefix which the shell will use for all temporary files.
     Note that this should include an initial part for the file name as
     well as any directory names.  The default is ‘/tmp/zsh’.

‘TMPSUFFIX’

     A filename suffix which the shell will use for temporary files
     created by process substitutions (e.g., ‘=(’LIST‘)’).  Note that
     the value should include a leading dot ‘.’ if intended to be
     interpreted as a file extension.  The default is not to append any
     suffix, thus this parameter should be assigned only when needed and
     then unset again.

‘WORDCHARS’ <S>

     A list of non-alphanumeric characters considered part of a word by
     the line editor.

‘ZBEEP’

     If set, this gives a string of characters, which can use all the
     same codes as the ‘bindkey’ command as described in *note The
     zsh/zle Module: 99, that will be output to the terminal instead of
     beeping.  This may have a visible instead of an audible effect; for
     example, the string ‘\e[?5h\e[?5l’ on a vt100 or xterm will have
     the effect of flashing reverse video on and off (if you usually use
     reverse video, you should use the string ‘\e[?5l\e[?5h’ instead).
     This takes precedence over the ‘NOBEEP’ option.

‘ZDOTDIR’

     The directory to search for shell startup files (.zshrc, etc), if
     not ‘$HOME’.

‘zle_bracketed_paste’

     This two-element array contains the terminal escape sequences for
     enabling and disabling the bracketed paste feature which allows ZLE
     to discern text that is pasted into the terminal.  These escape
     sequences are used to enable bracketed paste when ZLE is active and
     disable it at other times.  Unsetting the parameter has the effect
     of ensuring that bracketed paste remains disabled.  However, see
     also the ‘.term.extensions’ parameter which provides a single place
     to enable or disable terminal features.

‘zle_cursorform’

     An array describing contexts in which ZLE should change the shape
     and color of the cursor.  See ..  only:: man

          ‘Cursor Shape and Color’ in ‘zshzle(1)’

     Cursor Shape and Color

     .

‘zle_highlight’

     An array describing contexts in which ZLE should highlight the
     input text.  See *note Character Highlighting: 60.

‘ZLE_LINE_ABORTED’

     This parameter is set by the line editor when an error occurs.  It
     contains the line that was being edited at the point of the error.
     ‘print -zr -- $ZLE_LINE_ABORTED’ can be used to recover the line.
     Only the most recent line of this kind is remembered.

‘ZLE_REMOVE_SUFFIX_CHARS’

‘ZLE_SPACE_SUFFIX_CHARS’

     These parameters are used by the line editor.  In certain
     circumstances suffixes (typically space or slash) added by the
     completion system will be removed automatically, either because the
     next editing command was not an insertable character, or because
     the character was marked as requiring the suffix to be removed.

     These variables can contain the sets of characters that will cause
     the suffix to be removed.  If ‘ZLE_REMOVE_SUFFIX_CHARS’ is set,
     those characters will cause the suffix to be removed; if
     ‘ZLE_SPACE_SUFFIX_CHARS’ is set, those characters will cause the
     suffix to be removed and replaced by a space.

     If ‘ZLE_REMOVE_SUFFIX_CHARS’ is not set, the default behaviour is
     equivalent to:

           ZLE_REMOVE_SUFFIX_CHARS=$' \t\n;&|'

     If ‘ZLE_REMOVE_SUFFIX_CHARS’ is set but is empty, no characters
     have this behaviour.  ‘ZLE_SPACE_SUFFIX_CHARS’ takes precedence, so
     that the following:

           ZLE_SPACE_SUFFIX_CHARS=$'&|'

     causes the characters ‘&’ and ‘|’ to remove the suffix but to
     replace it with a space.

     To illustrate the difference, suppose that the option
     ‘AUTO_REMOVE_SLASH’ is in effect and the directory ‘DIR’ has just
     been completed, with an appended ‘/’, following which the user
     types ‘&’.  The default result is ‘DIR&’.  With
     ‘ZLE_REMOVE_SUFFIX_CHARS’ set but without including ‘&’ the result
     is ‘DIR/&’.  With ‘ZLE_SPACE_SUFFIX_CHARS’ set to include ‘&’ the
     result is ‘DIR &’.

     Note that certain completions may provide their own suffix removal
     or replacement behaviour which overrides the values described here.
     See the completion system documentation in ‘zshcompsys’.

‘ZLE_RPROMPT_INDENT’ <S>

     If set, used to give the indentation between the right hand side of
     the right prompt in the line editor as given by ‘RPS1’ or ‘RPROMPT’
     and the right hand side of the screen.  If not set, the value 1 is
     used.

     Typically this will be used to set the value to 0 so that the
     prompt appears flush with the right hand side of the screen.  This
     is not the default as many terminals do not handle this correctly,
     in particular when the prompt appears at the extreme bottom right
     of the screen.  Recent virtual terminals are more likely to handle
     this case correctly.  Some experimentation is necessary.


File: zsh.info,  Node: Options<2>,  Next: Shell Builtin Commands,  Prev: Parameters,  Up: Top

15 Options
**********

* Menu:

* Specifying Options::
* Description of Options::
* Option Aliases::
* Single Letter Options::


File: zsh.info,  Node: Specifying Options,  Next: Description of Options,  Up: Options<2>

15.1 Specifying Options
=======================

Options are primarily referred to by name.  These names are case
insensitive and underscores are ignored.  For example, ‘allexport’ is
equivalent to ‘A__lleXP_ort’.

The sense of an option name may be inverted by preceding it with ‘no’,
so ‘setopt No_Beep’ is equivalent to ‘unsetopt beep’.  This inversion
can only be done once, so ‘nonobeep’ is ‘not’ a synonym for ‘beep’.
Similarly, ‘tify’ is not a synonym for ‘nonotify’ (the inversion of
‘notify’).

Some options also have one or more single letter names.  There are two
sets of single letter options: one used by default, and another used to
emulate ‘sh’/‘ksh’ (used when the ‘SH_OPTION_LETTERS’ option is set).
The single letter options can be used on the shell command line, or with
the ‘set’, ‘setopt’ and ‘unsetopt’ builtins, as normal Unix options
preceded by ‘-’.

The sense of the single letter options may be inverted by using ‘+’
instead of ‘-’.  Some of the single letter option names refer to an
option being off, in which case the inversion of that name refers to the
option being on.  For example, ‘+n’ is the short name of ‘exec’, and
‘-n’ is the short name of its inversion, ‘noexec’.

In strings of single letter options supplied to the shell at startup,
trailing whitespace will be ignored; for example the string ‘-f’ will be
treated just as ‘-f’, but the string ‘-f i’ is an error.  This is
because many systems which implement the ‘#!’ mechanism for calling
scripts do not strip trailing whitespace.

It is possible for options to be set within a function scope.  See the
description of the option ‘LOCAL_OPTIONS’ below.


File: zsh.info,  Node: Description of Options,  Next: Option Aliases,  Prev: Specifying Options,  Up: Options<2>

15.2 Description of Options
===========================

In the following list, options set by default in all emulations are
marked <D>; those set by default only in csh, ksh, sh, or zsh emulations
are marked <C>, <K>, <S>, <Z> as appropriate.  When listing options (by
‘setopt’, ‘unsetopt’, ‘set -o’ or ‘set +o’), those turned on by default
appear in the list prefixed with ‘no’.  Hence (unless ‘KSH_OPTION_PRINT’
is set), ‘setopt’ shows all options whose settings are changed from the
default.

* Menu:

* Changing Directories::
* Completion: Completion<2>.
* Expansion and Globbing::
* History::
* Initialisation::
* Input/Output::
* Job Control::
* Prompting::
* Scripts and Functions::
* Shell Emulation::
* Shell State: Shell State<2>.
* Zle::


File: zsh.info,  Node: Changing Directories,  Next: Completion<2>,  Up: Description of Options

15.2.1 Changing Directories
---------------------------

‘AUTO_CD’ (‘-J’)

     If a command is issued that can’t be executed as a normal command,
     and the command is the name of a directory, perform the ‘cd’
     command to that directory.  This option is only applicable if the
     option ‘SHIN_STDIN’ is set, i.e.  if commands are being read from
     standard input.  The option is designed for interactive use; it is
     recommended that ‘cd’ be used explicitly in scripts to avoid
     ambiguity.

‘AUTO_PUSHD’ (‘-N’)

     Make ‘cd’ push the old directory onto the directory stack.

‘CDABLE_VARS’ (‘-T’)

     If the argument to a ‘cd’ command (or an implied ‘cd’ with the
     ‘AUTO_CD’ option set) is not a directory, and does not begin with a
     slash, try to expand the expression as if it were preceded by a ‘~’
     (see *note Filename Expansion: 5d.).

‘CD_SILENT’

     Never print the working directory after a ‘cd’ (whether explicit or
     implied with the ‘AUTO_CD’ option set).  ‘cd’ normally prints the
     working directory when the argument given to it was ‘-’, a stack
     entry, or the name of a directory found under ‘CDPATH’.  Note that
     this is distinct from ‘pushd’’s stack-printing behaviour, which is
     controlled by ‘PUSHD_SILENT’.  This option overrides the
     printing-related effects of ‘POSIX_CD’.

‘CHASE_DOTS’

     When changing to a directory containing a path segment ‘..’ which
     would otherwise be treated as canceling the previous segment in the
     path (in other words, ‘foo/..’ would be removed from the path, or
     if ‘..’ is the first part of the path, the last part of the current
     working directory would be removed), instead resolve the path to
     the physical directory.  This option is overridden by
     ‘CHASE_LINKS’.

     For example, suppose ‘/foo/bar’ is a link to the directory
     ‘/alt/rod’.  Without this option set, ‘cd /foo/bar/..’ changes to
     ‘/foo’; with it set, it changes to ‘/alt’.  The same applies if the
     current directory is ‘/foo/bar’ and ‘cd ..’ is used.  Note that all
     other symbolic links in the path will also be resolved.

‘CHASE_LINKS’ (‘-w’)

     Resolve symbolic links to their true values when changing
     directory.  This also has the effect of ‘CHASE_DOTS’, i.e.  a ‘..’
     path segment will be treated as referring to the physical parent,
     even if the preceding path segment is a symbolic link.

‘POSIX_CD’ <K> <S>

     Modifies the behaviour of ‘cd’, ‘chdir’ and ‘pushd’ commands to
     make them more compatible with the POSIX standard.  The behaviour
     with the option unset is described in the documentation for the
     ‘cd’ builtin in ‘zshbuiltins’.  If the option is set, the shell
     does not test for directories beneath the local directory (‘.’)
     until after all directories in ‘cdpath’ have been tested, and the
     ‘cd’ and ‘chdir’ commands do not recognise arguments of the form
     {‘+|-’}:var:‘n’ as directory stack entries.

     Also, if the option is set, the conditions under which the shell
     prints the new directory after changing to it are modified.  It is
     no longer restricted to interactive shells (although printing of
     the directory stack with ‘pushd’ is still limited to interactive
     shells); and any use of a component of ‘CDPATH’, including a ‘.’
     but excluding an empty component that is otherwise treated as ‘.’,
     causes the directory to be printed.

‘PUSHD_IGNORE_DUPS’

     Don’t push multiple copies of the same directory onto the directory
     stack.

‘PUSHD_MINUS’

     Exchanges the meanings of ‘+’ and ‘-’ when used with a number to
     specify a directory in the stack.

‘PUSHD_SILENT’ (‘-E’)

     Do not print the directory stack after ‘pushd’ or ‘popd’.

‘PUSHD_TO_HOME’ (‘-D’)

     Have ‘pushd’ with no arguments act like ‘pushd $HOME’.


File: zsh.info,  Node: Completion<2>,  Next: Expansion and Globbing,  Prev: Changing Directories,  Up: Description of Options

15.2.2 Completion
-----------------

‘ALWAYS_LAST_PROMPT’ <D>

     If unset, key functions that list completions try to return to the
     last prompt if given a numeric argument.  If set these functions
     try to return to the last prompt if given ‘no’ numeric argument.

‘ALWAYS_TO_END’

     If a completion is performed with the cursor within a word, and a
     full completion is inserted, the cursor is moved to the end of the
     word.  That is, the cursor is moved to the end of the word if
     either a single match is inserted or menu completion is performed.

‘AUTO_LIST’ (‘-9’) <D>

     Automatically list choices on an ambiguous completion.

‘AUTO_MENU’ <D>

     Automatically use menu completion after the second consecutive
     request for completion, for example by pressing the tab key
     repeatedly.  This option is overridden by ‘MENU_COMPLETE’.

‘AUTO_NAME_DIRS’

     Any global parameter that is set to the absolute name of a
     directory immediately becomes a name for that directory, that will
     be used by the ‘%~’ and related prompt sequences, and will be
     available when completion is performed on a word starting with ‘~’.
     (Otherwise, the parameter must be used in the form ‘~’PARAM first.)

‘AUTO_PARAM_KEYS’ <D>

     If a parameter name was completed and a following character
     (normally a space) automatically inserted, and the next character
     typed is one of those that have to come directly after the name
     (like ‘}’, ‘:’, etc.), the automatically added character is
     deleted, so that the character typed comes immediately after the
     parameter name.  Completion in a brace expansion is affected
     similarly: the added character is a ‘,’, which will be removed if
     ‘}’ is typed next.

‘AUTO_PARAM_SLASH’ <D>

     If a parameter is completed whose content is the name of a
     directory, then add a trailing slash instead of a space.

‘AUTO_REMOVE_SLASH’ <D>

     When the last character resulting from a completion is a slash and
     the next character typed is a word delimiter, a slash, or a
     character that ends a command (such as a semicolon or an
     ampersand), remove the slash.

‘BASH_AUTO_LIST’

     On an ambiguous completion, automatically list choices when the
     completion function is called twice in succession.  This takes
     precedence over ‘AUTO_LIST’.  The setting of ‘LIST_AMBIGUOUS’ is
     respected.  If ‘AUTO_MENU’ is set, the menu behaviour will then
     start with the third press.  Note that this will not work with
     ‘MENU_COMPLETE’, since repeated completion calls immediately cycle
     through the list in that case.

‘COMPLETE_ALIASES’

     Prevents aliases on the command line from being internally
     substituted before completion is attempted.  The effect is to make
     the alias a distinct command for completion purposes.

‘COMPLETE_IN_WORD’

     If unset, the cursor is set to the end of the word if completion is
     started.  Otherwise it stays there and completion is done from both
     ends.

‘GLOB_COMPLETE’

     When the current word has a glob pattern, do not insert all the
     words resulting from the expansion but generate matches as for
     completion and cycle through them like ‘MENU_COMPLETE’.  The
     matches are generated as if a ‘*’ was added to the end of the word,
     or inserted at the cursor when ‘COMPLETE_IN_WORD’ is set.  This
     actually uses pattern matching, not globbing, so it works not only
     for files but for any completion, such as options, user names, etc.

     Note that when the pattern matcher is used, matching control (for
     example, case-insensitive or anchored matching) cannot be used.
     This limitation only applies when the current word contains a
     pattern; simply turning on the ‘GLOB_COMPLETE’ option does not have
     this effect.

‘HASH_LIST_ALL’ <D>

     Whenever a command completion or spelling correction is attempted,
     make sure the entire command path is hashed first.  This makes the
     first completion slower but avoids false reports of spelling
     errors.

‘LIST_AMBIGUOUS’ <D>

     This option works when ‘AUTO_LIST’ or ‘BASH_AUTO_LIST’ is also set.
     If there is an unambiguous prefix to insert on the command line,
     that is done without a completion list being displayed; in other
     words, auto-listing behaviour only takes place when nothing would
     be inserted.  In the case of ‘BASH_AUTO_LIST’, this means that the
     list will be delayed to the third call of the function.

‘LIST_BEEP’ <D>

     Beep on an ambiguous completion.  More accurately, this forces the
     completion widgets to return status 1 on an ambiguous completion,
     which causes the shell to beep if the option ‘BEEP’ is also set;
     this may be modified if completion is called from a user-defined
     widget.

‘LIST_PACKED’

     Try to make the completion list smaller (occupying less lines) by
     printing the matches in columns with different widths.

‘LIST_ROWS_FIRST’

     Lay out the matches in completion lists sorted horizontally, that
     is, the second match is to the right of the first one, not under it
     as usual.

‘LIST_TYPES’ (‘-X’) <D>

     When listing files that are possible completions, show the type of
     each file with a trailing identifying mark.

‘MENU_COMPLETE’ (‘-Y’)

     On an ambiguous completion, instead of listing possibilities or
     beeping, insert the first match immediately.  Then when completion
     is requested again, remove the first match and insert the second
     match, etc.  When there are no more matches, go back to the first
     one again.  ‘reverse-menu-complete’ may be used to loop through the
     list in the other direction.  This option overrides ‘AUTO_MENU’.

‘REC_EXACT’ (‘-S’)

     If the string on the command line exactly matches one of the
     possible completions, it is accepted, even if there is another
     completion (i.e.  that string with something else added) that also
     matches.


File: zsh.info,  Node: Expansion and Globbing,  Next: History,  Prev: Completion<2>,  Up: Description of Options

15.2.3 Expansion and Globbing
-----------------------------

‘BAD_PATTERN’ (‘+2’) <C> <Z>

     If a pattern for filename generation is badly formed, print an
     error message.  (If this option is unset, the pattern will be left
     unchanged.)

‘BARE_GLOB_QUAL’ <Z>

     In a glob pattern, treat a trailing set of parentheses as a
     qualifier list, if it contains no unquoted ‘|’, ‘(’ or (if special)
     ‘~’ characters.  See *note Filename Generation: 17.

‘BRACE_CCL’

     Expand expressions in braces which would not otherwise undergo
     brace expansion to a lexically ordered list of all the characters.
     See *note Brace Expansion: 77.

‘CASE_GLOB’ <D>

     Make globbing (filename generation) sensitive to case.  Note that
     other uses of patterns are always sensitive to case.  If the option
     is unset, the presence of any character which is special to
     filename generation will cause case-insensitive matching.  For
     example, ‘cvs(/)’ can match the directory ‘CVS’ owing to the
     presence of the globbing flag (unless the option ‘BARE_GLOB_QUAL’
     is unset).

‘CASE_MATCH’ <D>

     Make regular expressions using the ‘zsh/regex’ module (including
     matches with ‘=~’) sensitive to case.

‘CASE_PATHS’

     If ‘CASE_PATHS’ is not set (the default), ‘CASE_GLOB’ affects the
     interpretation of ‘every’ path component, whenever a special
     character appears in ‘any’ component.  When ‘CASE_PATHS’ is set,
     file path components that do ‘not’ contain special filename
     generation characters are always sensitive to case, thus
     restricting ‘NO_CASE_GLOB’ to components that contain globbing
     characters.

     Note that if the filesystem itself is not sensitive to case, then
     ‘CASE_PATHS’ has no effect.

‘CSH_NULL_GLOB’ <C>

     If a pattern for filename generation has no matches, delete the
     pattern from the argument list; do not report an error unless all
     the patterns in a command have no matches.  Overrides ‘NOMATCH’.

‘EQUALS’ <Z>

     Perform ‘=’ filename expansion.  (See *note Filename Expansion:
     5d.)

‘EXTENDED_GLOB’

     Treat the ‘#’, ‘~’ and ‘^’ characters as part of patterns for
     filename generation, etc.  (An initial unquoted ‘~’ always produces
     named directory expansion.)

‘FORCE_FLOAT’

     Constants in arithmetic evaluation will be treated as floating
     point even without the use of a decimal point; the values of
     integer variables will be converted to floating point when used in
     arithmetic expressions.  Integers in any base will be converted.

‘GLOB’ (‘+F’, ksh: ‘+f’) <D>

     Perform filename generation (globbing).  (See *note Filename
     Generation: 17.)

‘GLOB_ASSIGN’ <C>

     If this option is set, filename generation (globbing) is performed
     on the right hand side of scalar parameter assignments of the form
     ‘:var:‘name’‘=’PATTERN (e.g.  ‘foo=*’).  If the result has more
     than one word the parameter will become an array with those words
     as arguments.  This option is provided for backwards compatibility
     only: globbing is always performed on the right hand side of array
     assignments of the form NAME‘=(’VALUE‘)’ (e.g.  ‘foo=(*)’) and this
     form is recommended for clarity; with this option set, it is not
     possible to predict whether the result will be an array or a
     scalar.

‘GLOB_DOTS’ (‘-4’)

     Do not require a leading ‘.’ in a filename to be matched
     explicitly.

‘GLOB_STAR_SHORT’

     When this option is set and the default zsh-style globbing is in
     effect, the pattern ‘**/*’ can be abbreviated to ‘**’ and the
     pattern ‘***/*’ can be abbreviated to ‘***’.  Hence ‘**.c’ finds a
     file ending in ‘.c’ in any subdirectory, and ‘***.c’ does the same
     while also following symbolic links.  A ‘/’ immediately after the
     ‘**’ or ‘***’ forces the pattern to be treated as the unabbreviated
     form.

‘GLOB_SUBST’ <C> <K> <S>

     Treat any characters resulting from parameter expansion as being
     eligible for filename expansion and filename generation, and any
     characters resulting from command substitution as being eligible
     for filename generation.  Braces (and commas in between) do not
     become eligible for expansion.

‘HIST_SUBST_PATTERN’

     Substitutions using the ‘:s’ and ‘:&’ history modifiers are
     performed with pattern matching instead of string matching.  This
     occurs wherever history modifiers are valid, including glob
     qualifiers and parameters.  See *note Modifiers: 6b.

‘IGNORE_BRACES’ (‘-I’) <S>

     Do not perform brace expansion.  For historical reasons this also
     includes the effect of the ‘IGNORE_CLOSE_BRACES’ option.

‘IGNORE_CLOSE_BRACES’

     When neither this option nor ‘IGNORE_BRACES’ is set, a sole close
     brace character ‘}’ is syntactically significant at any point on a
     command line.  This has the effect that no semicolon or newline is
     necessary before the brace terminating a function or current shell
     construct.  When either option is set, a closing brace is
     syntactically significant only in command position.  Unlike
     ‘IGNORE_BRACES’, this option does not disable brace expansion.

     For example, with both options unset a function may be defined in
     the following fashion:

           args() { echo $# }

     while if either option is set, this does not work and something
     equivalent to the following is required:

           args() { echo $#; }

‘KSH_GLOB’ <K>

     In pattern matching, the interpretation of parentheses is affected
     by a preceding ‘@’, ‘*’, ‘+’, ‘?’ or ‘!’.  See *note Filename
     Generation: 17.

‘MAGIC_EQUAL_SUBST’

     All unquoted arguments of the form ANYTHING‘=’EXPRESSION appearing
     after the command name have filename expansion (that is, where
     EXPRESSION has a leading ‘~’ or ‘=’) performed on EXPRESSION as if
     it were a parameter assignment.  The argument is not otherwise
     treated specially; it is passed to the command as a single
     argument, and not used as an actual parameter assignment.  For
     example, in ‘echo foo=~/bar:~/rod’, both occurrences of ‘~’ would
     be replaced.  Note that this happens anyway with ‘typeset’ and
     similar statements.

     This option respects the setting of the ‘KSH_TYPESET’ option.  In
     other words, if both options are in effect, arguments looking like
     assignments will not undergo word splitting.

‘MARK_DIRS’ (‘-8’, ksh: ‘-X’)

     Append a trailing ‘/’ to all directory names resulting from
     filename generation (globbing).

‘MULTIBYTE’ <D>

     Respect multibyte characters when found in strings.  When this
     option is set, strings are examined using the system library to
     determine how many bytes form a character, depending on the current
     locale.  This affects the way characters are counted in pattern
     matching, parameter values and various delimiters.

     The option is on by default if the shell was compiled with
     ‘MULTIBYTE_SUPPORT’; otherwise it is off by default and has no
     effect if turned on.

     If the option is off a single byte is always treated as a single
     character.  This setting is designed purely for examining strings
     known to contain raw bytes or other values that may not be
     characters in the current locale.  It is not necessary to unset the
     option merely because the character set for the current locale does
     not contain multibyte characters.

     The option does not affect the shell’s editor, which always uses
     the locale to determine multibyte characters.  This is because the
     character set displayed by the terminal emulator is independent of
     shell settings.

‘NOMATCH’ (‘+3’) <C> <Z>

     If a pattern for filename generation has no matches, print an
     error, instead of leaving it unchanged in the argument list.  This
     also applies to file expansion of an initial ‘~’ or ‘=’.

‘NULL_GLOB’ (‘-G’)

     If a pattern for filename generation has no matches, delete the
     pattern from the argument list instead of reporting an error.
     Overrides ‘NOMATCH’.

‘NUMERIC_GLOB_SORT’

     If numeric filenames are matched by a filename generation pattern,
     sort the filenames numerically rather than lexicographically.

‘RC_EXPAND_PARAM’ (‘-P’)

     Array expansions of the form FOO‘${’XX‘}’BAR, where the parameter
     XX is set to ‘(’A B C‘)’, are substituted with FOOABAR FOOBBAR
     FOOCBAR instead of the default FOOA B CBAR.  Note that an empty
     array will therefore cause all arguments to be removed.

‘REMATCH_PCRE’

     If set, regular expression matching with the ‘=~’ operator will use
     Perl-Compatible Regular Expressions from the PCRE library.  (The
     ‘zsh/pcre’ module must be available.)  If not set, regular
     expressions will use the extended regexp syntax provided by the
     system libraries.

‘SH_GLOB’ <K> <S>

     Disables the special meaning of ‘(’, ‘|’, ‘)’ and ‘‘<’’ for
     globbing the result of parameter and command substitutions, and in
     some other places where the shell accepts patterns.  If ‘SH_GLOB’
     is set but ‘KSH_GLOB’ is not, the shell allows the interpretation
     of subshell expressions enclosed in parentheses in some cases where
     there is no space before the opening parenthesis, e.g.  ‘!(true)’
     is interpreted as if there were a space after the ‘!’.  This option
     is set by default if zsh is invoked as ‘sh’ or ‘ksh’.

‘UNSET’ (‘+u’, ksh: ‘+u’) <K> <S> <Z>

     Treat unset parameters as if they were empty when substituting, and
     as if they were zero when reading their values in arithmetic
     expansion and arithmetic commands.  Otherwise they are treated as
     an error.

‘WARN_CREATE_GLOBAL’

     Print a warning message when a global parameter is created in a
     function by an assignment or in math context.  This often indicates
     that a parameter has not been declared local when it should have
     been.  Parameters explicitly declared global from within a function
     using ‘typeset -g’ do not cause a warning.  Note that there is no
     warning when a local parameter is assigned to in a nested function,
     which may also indicate an error.

‘WARN_NESTED_VAR’

     Print a warning message when an existing parameter from an
     enclosing function scope, or global, is set in a function by an
     assignment or in math context.  Assignment to shell special
     parameters does not cause a warning.  This is the companion to
     ‘WARN_CREATE_GLOBAL’ as in this case the warning is only printed
     when a parameter is ‘not’ created.  Where possible, use of ‘typeset
     -g’ to set the parameter suppresses the error, but note that this
     needs to be used every time the parameter is set.  To restrict the
     effect of this option to a single function scope, use ‘functions
     -W’.

     For example, the following code produces a warning for the
     assignment inside the function ‘nested’ as that overrides the value
     within ‘toplevel’

           toplevel() {
             local foo="in fn"
             nested
           }
           nested() {
                foo="in nested"
           }
           setopt warn_nested_var
           toplevel


File: zsh.info,  Node: History,  Next: Initialisation,  Prev: Expansion and Globbing,  Up: Description of Options

15.2.4 History
--------------

‘APPEND_HISTORY’ <D>

     If this is set, zsh sessions will append their history list to the
     history file, rather than replace it.  Thus, multiple parallel zsh
     sessions will all have the new entries from their history lists
     added to the history file, in the order that they exit.  The file
     will still be periodically re-written to trim it when the number of
     lines grows 20% beyond the value specified by ‘$SAVEHIST’ (see also
     the ‘HIST_SAVE_BY_COPY’ option).

‘BANG_HIST’ (‘+K’) <C> <Z>

     Perform textual history expansion, ‘csh’-style, treating the
     character ‘!’ specially.

‘EXTENDED_HISTORY’ <C>

     Save each command’s beginning timestamp (in seconds since the
     epoch) and the duration (in seconds) to the history file.  The
     format of this prefixed data is:

     ‘:’ <BEGINNING TIME>‘:’<ELAPSED SECONDS>‘;’<COMMAND>.

‘HIST_ALLOW_CLOBBER’

     Add ‘|’ to output redirections in the history.  This allows history
     references to clobber files even when ‘CLOBBER’ is unset.

‘HIST_BEEP’ <D>

     Beep in ZLE when a widget attempts to access a history entry which
     isn’t there.

‘HIST_EXPIRE_DUPS_FIRST’

     If the internal history needs to be trimmed to add the current
     command line, setting this option will cause the oldest history
     event that has a duplicate to be lost before losing a unique event
     from the list.  You should be sure to set the value of ‘HISTSIZE’
     to a larger number than ‘SAVEHIST’ in order to give you some room
     for the duplicated events, otherwise this option will behave just
     like ‘HIST_IGNORE_ALL_DUPS’ once the history fills up with unique
     events.

‘HIST_FCNTL_LOCK’

     When writing out the history file, by default zsh uses ad-hoc file
     locking to avoid known problems with locking on some operating
     systems.  With this option locking is done by means of the system’s
     ‘fcntl’ call, where this method is available.  On recent operating
     systems this may provide better performance, in particular avoiding
     history corruption when files are stored on NFS.

‘HIST_FIND_NO_DUPS’

     When searching for history entries in the line editor, do not
     display duplicates of a line previously found, even if the
     duplicates are not contiguous.

‘HIST_IGNORE_ALL_DUPS’

     If a new command line being added to the history list duplicates an
     older one, the older command is removed from the list (even if it
     is not the previous event).

‘HIST_IGNORE_DUPS’ (‘-h’)

     Do not enter command lines into the history list if they are
     duplicates of the previous event.

‘HIST_IGNORE_SPACE’ (‘-g’)

     Remove command lines from the history list when the first character
     on the line is a space, or when one of the expanded aliases
     contains a leading space.  Only normal aliases (not global or
     suffix aliases) have this behaviour.  Note that the command lingers
     in the internal history until the next command is entered before it
     vanishes, allowing you to briefly reuse or edit the line.  If you
     want to make it vanish right away without entering another command,
     type a space and press return.

‘HIST_LEX_WORDS’

     By default, shell history that is read in from files is split into
     words on all white space.  This means that arguments with quoted
     whitespace are not correctly handled, with the consequence that
     references to words in history lines that have been read from a
     file may be inaccurate.  When this option is set, words read in
     from a history file are divided up in a similar fashion to normal
     shell command line handling.  Although this produces more
     accurately delimited words, if the size of the history file is
     large this can be slow.  Trial and error is necessary to decide.

‘HIST_NO_FUNCTIONS’

     Remove function definitions from the history list.  Note that the
     function lingers in the internal history until the next command is
     entered before it vanishes, allowing you to briefly reuse or edit
     the definition.

‘HIST_NO_STORE’

     Remove the ‘history’ (‘fc -l’) command from the history list when
     invoked.  Note that the command lingers in the internal history
     until the next command is entered before it vanishes, allowing you
     to briefly reuse or edit the line.

‘HIST_REDUCE_BLANKS’

     Remove superfluous blanks from each command line being added to the
     history list.

‘HIST_SAVE_BY_COPY’ <D>

     When the history file is re-written, we normally write out a copy
     of the file named ‘$HISTFILE.new’ and then rename it over the old
     one.  However, if this option is unset, we instead truncate the old
     history file and write out the new version in-place.  If one of the
     history-appending options is enabled, this option only has an
     effect when the enlarged history file needs to be re-written to
     trim it down to size.  Disable this only if you have special needs,
     as doing so makes it possible to lose history entries if zsh gets
     interrupted during the save.

     When writing out a copy of the history file, zsh preserves the old
     file’s permissions and group information, but will refuse to write
     out a new file if it would change the history file’s owner.

‘HIST_SAVE_NO_DUPS’

     When writing out the history file, older commands that duplicate
     newer ones are omitted.

‘HIST_VERIFY’

     Whenever the user enters a line with history expansion, don’t
     execute the line directly; instead, perform history expansion and
     reload the line into the editing buffer.

‘INC_APPEND_HISTORY’

     This option works like ‘APPEND_HISTORY’ except that new history
     lines are added to the ‘$HISTFILE’ incrementally (as soon as they
     are entered), rather than waiting until the shell exits.  The file
     will still be periodically re-written to trim it when the number of
     lines grows 20% beyond the value specified by ‘$SAVEHIST’ (see also
     the ‘HIST_SAVE_BY_COPY’ option).

‘INC_APPEND_HISTORY_TIME’

     This option is a variant of ‘INC_APPEND_HISTORY’ in which, where
     possible, the history entry is written out to the file after the
     command is finished, so that the time taken by the command is
     recorded correctly in the history file in ‘EXTENDED_HISTORY’
     format.  This means that the history entry will not be available
     immediately from other instances of the shell that are using the
     same history file.

     This option is only useful if ‘INC_APPEND_HISTORY’ and
     ‘SHARE_HISTORY’ are turned off.  The three options should be
     considered mutually exclusive.

‘SHARE_HISTORY’ <K>

     This option both imports new commands from the history file, and
     also causes your typed commands to be appended to the history file
     (the latter is like specifying ‘INC_APPEND_HISTORY’, which should
     be turned off if this option is in effect).  The history lines are
     also output with timestamps ala ‘EXTENDED_HISTORY’ (which makes it
     easier to find the spot where we left off reading the file after it
     gets re-written).

     By default, history movement commands visit the imported lines as
     well as the local lines, but you can toggle this on and off with
     the set-local-history zle binding.  It is also possible to create a
     zle widget that will make some commands ignore imported commands,
     and some include them.

     If you find that you want more control over when commands get
     imported, you may wish to turn ‘SHARE_HISTORY’ off,
     ‘INC_APPEND_HISTORY’ or ‘INC_APPEND_HISTORY_TIME’ (see above) on,
     and then manually import commands whenever you need them using ‘fc
     -RI’.


File: zsh.info,  Node: Initialisation,  Next: Input/Output,  Prev: History,  Up: Description of Options

15.2.5 Initialisation
---------------------

‘ALL_EXPORT’ (‘-a’, ksh: ‘-a’)

     All parameters subsequently defined are automatically exported.

‘GLOBAL_EXPORT’ <Z>

     If this option is set, passing the ‘-x’ flag to the builtins
     ‘declare’, ‘float’, ‘integer’, ‘readonly’ and ‘typeset’ (but not
     ‘local’) will also set the ‘-g’ flag; hence parameters exported to
     the environment will not be made local to the enclosing function,
     unless they were already or the flag ‘+g’ is given explicitly.  If
     the option is unset, exported parameters will be made local in just
     the same way as any other parameter.

     This option is set by default for backward compatibility; it is not
     recommended that its behaviour be relied upon.  Note that the
     builtin ‘export’ always sets both the ‘-x’ and ‘-g’ flags, and
     hence its effect extends beyond the scope of the enclosing
     function; this is the most portable way to achieve this behaviour.

‘GLOBAL_RCS’ (‘+d’) <D>

     If this option is unset, the startup files ‘/etc/zprofile’,
     ‘/etc/zshrc’, ‘/etc/zlogin’ and ‘/etc/zlogout’ will not be run.  It
     can be disabled and re-enabled at any time, including inside local
     startup files (‘.zshrc’, etc.).

‘RCS’ (‘+f’) <D>

     After ‘/etc/zshenv’ is sourced on startup, source the ‘.zshenv’,
     ‘/etc/zprofile’, ‘.zprofile’, ‘/etc/zshrc’, ‘.zshrc’,
     ‘/etc/zlogin’, ‘.zlogin’, and ‘.zlogout’ files, as described in
     *note Startup/Shutdown Files: e.  If this option is unset, the
     ‘/etc/zshenv’ file is still sourced, but any of the others will not
     be; it can be set at any time to prevent the remaining startup
     files after the currently executing one from being sourced.


File: zsh.info,  Node: Input/Output,  Next: Job Control,  Prev: Initialisation,  Up: Description of Options

15.2.6 Input/Output
-------------------

‘ALIASES’ <D>

     Expand aliases.

‘CLOBBER’ (‘+C’, ksh: ‘+C’) <D>

     Allows ‘>’ redirection to truncate existing files.  Otherwise ‘>!’
     or ‘>|’ must be used to truncate a file.

     If the option is not set, and the option ‘APPEND_CREATE’ is also
     not set, ‘>>!’ or ‘>>|’ must be used to create a file.  If either
     option is set, ‘>>’ may be used.

‘CLOBBER_EMPTY’

     This option is only used if the option ‘CLOBBER’ is not set: note
     that it is set by default.

     If this option is set, then regular files of zero length may be
     overwritten (‘clobbered’).  Note that it is possible another
     process has written to the file between this test and use of the
     file by the current process.  This option should therefore not be
     used in cases where files to be clobbered may be written to
     asynchronously.

‘CORRECT’ (‘-0’)

     Try to correct the spelling of commands.  Note that, when the
     ‘HASH_LIST_ALL’ option is not set or when some directories in the
     path are not readable, this may falsely report spelling errors the
     first time some commands are used.

     Refer to the shell variable ‘SPROMPT’ for an explanation of the
     ‘[nyae]’ (no/yes/abort/edit) prompt that is offered.

     The shell variable ‘CORRECT_IGNORE’ may be set to a pattern to
     match words that will never be offered as corrections.

‘CORRECT_ALL’ (‘-O’)

     Try to correct the spelling of all arguments in a line, in order
     from left to right, treating each as a file name.  Answering ‘a’ or
     ‘e’ at any prompt stops all corrections, otherwise every correction
     is prompted for.

     The shell variable ‘CORRECT_IGNORE_FILE’ may be set to a pattern to
     match file names that will never be offered as corrections.

‘DVORAK’

     Use the Dvorak keyboard instead of the standard qwerty keyboard as
     a basis for examining spelling mistakes for the ‘CORRECT’ and
     ‘CORRECT_ALL’ options and the ‘spell-word’ editor command.

‘FLOW_CONTROL’ <D>

     If this option is unset, output flow control via start/stop
     characters (usually assigned to ^S/^Q) is disabled in the shell’s
     editor.

‘IGNORE_EOF’ (‘-7’)

     Do not exit on end-of-file.  Require the use of ‘exit’ or ‘logout’
     instead.  However, ten consecutive EOFs will cause the shell to
     exit anyway, to avoid the shell hanging if its tty goes away.

     Also, if this option is set and the Zsh Line Editor is used,
     widgets implemented by shell functions can be bound to EOF
     (normally Control-D) without printing the normal warning message.
     This works only for normal widgets, not for completion widgets.

‘INTERACTIVE_COMMENTS’ (‘-k’) <K> <S>

     Allow comments even in interactive shells.

‘HASH_CMDS’ <D>

     Note the location of each command the first time it is executed.
     Subsequent invocations of the same command will use the saved
     location, avoiding a path search.  If this option is unset, no path
     hashing is done at all.  However, when ‘CORRECT’ is set, commands
     whose names do not appear in the functions or aliases hash tables
     are hashed in order to avoid reporting them as spelling errors.

‘HASH_DIRS’ <D>

     Whenever a command name is hashed, hash the directory containing
     it, as well as all directories that occur earlier in the path.  Has
     no effect if neither ‘HASH_CMDS’ nor ‘CORRECT’ is set.

‘HASH_EXECUTABLES_ONLY’

     When hashing commands because of ‘HASH_CMDS’, check that the file
     to be hashed is actually an executable.  This option is unset by
     default as if the path contains a large number of commands, or
     consists of many remote files, the additional tests can take a long
     time.  Trial and error is needed to show if this option is
     beneficial.

‘MAIL_WARNING’ (‘-U’)

     Print a warning message if a mail file has been accessed since the
     shell last checked.

‘PATH_DIRS’ (‘-Q’)

     Perform a path search even on command names with slashes in them.
     Thus if ‘/usr/local/bin’ is in the user’s path, and he or she types
     ‘X11/xinit’, the command ‘/usr/local/bin/X11/xinit’ will be
     executed (assuming it exists).  Commands explicitly beginning with
     ‘/’, ‘./’ or ‘../’ are not subject to the path search.  This also
     applies to the ‘.’ and ‘source’ builtins.

     Note that subdirectories of the current directory are always
     searched for executables specified in this form.  This takes place
     before any search indicated by this option, and regardless of
     whether ‘.’ or the current directory appear in the command search
     path.

‘PATH_SCRIPT’ <K> <S>

     If this option is not set, a script passed as the first non-option
     argument to the shell must contain the name of the file to open.
     If this option is set, and the script does not specify a directory
     path, the script is looked for first in the current directory, then
     in the command path.  See *note Invocation: a3.

‘PRINT_EIGHT_BIT’

     Print eight bit characters literally in completion lists, etc.
     This option is not necessary if your system correctly returns the
     printability of eight bit characters (see ‘ctype(3)’).

‘PRINT_EXIT_VALUE’ (‘-1’)

     Print the exit value of programs with non-zero exit status.  This
     is only available at the command line in interactive shells.

‘RC_QUOTES’

     Allow the character sequence ‘'’’ to signify a single quote within
     singly quoted strings.  Note this does not apply in quoted strings
     using the format ‘$'’…‘'’, where a backslashed single quote can be
     used.

‘RM_STAR_SILENT’ (‘-H’) <K> <S>

     Do not query the user before executing ‘rm *’ or ‘rm path/*’.

‘RM_STAR_WAIT’

     If querying the user before executing ‘rm *’ or ‘rm path/*’, first
     wait ten seconds and ignore anything typed in that time.  This
     avoids the problem of reflexively answering ‘yes’ to the query when
     one didn’t really mean it.  The wait and query can always be
     avoided by expanding the ‘*’ in ZLE (with tab).

‘SHORT_LOOPS’ <C> <Z>

     Allow the short forms of ‘for’, ‘repeat’, ‘select’, ‘if’, and
     ‘function’ constructs.

‘SHORT_REPEAT’

     Allow the short form ‘repeat’ as ‘SHORT_LOOPS’ but without enabling
     it for the other constructs.

‘SUN_KEYBOARD_HACK’ (‘-L’)

     If a line ends with a backquote, and there are an odd number of
     backquotes on the line, ignore the trailing backquote.  This is
     useful on some keyboards where the return key is too small, and the
     backquote key lies annoyingly close to it.  As an alternative the
     variable ‘KEYBOARD_HACK’ lets you choose the character to be
     removed.


File: zsh.info,  Node: Job Control,  Next: Prompting,  Prev: Input/Output,  Up: Description of Options

15.2.7 Job Control
------------------

‘AUTO_CONTINUE’

     With this option set, stopped jobs that are removed from the job
     table with the ‘disown’ builtin command are automatically sent a
     ‘CONT’ signal to make them running.

‘AUTO_RESUME’ (‘-W’)

     Treat single word simple commands without redirection as candidates
     for resumption of an existing job.

‘BG_NICE’ (‘-6’) <C> <Z>

     Run all background jobs at a lower priority.  This option is set by
     default.

‘CHECK_JOBS’ <Z>

     Report the status of background and suspended jobs before exiting a
     shell with job control; a second attempt to exit the shell will
     succeed.  ‘NO_CHECK_JOBS’ is best used only in combination with
     ‘NO_HUP’, else such jobs will be killed automatically.

     The check is omitted if the commands run from the previous command
     line included a ‘jobs’ command, since it is assumed the user is
     aware that there are background or suspended jobs.  A ‘jobs’
     command run from one of the hook functions defined in *note Special
     Functions: a5. is not counted for this purpose.

‘CHECK_RUNNING_JOBS’ <Z>

     Check for both running and suspended jobs when ‘CHECK_JOBS’ is
     enabled.  When this option is disabled, zsh checks only for
     suspended jobs, which matches the default behavior of bash.

     This option has no effect unless ‘CHECK_JOBS’ is set.

‘HUP’ <Z>

     Send the ‘HUP’ signal to running jobs when the shell exits.

‘LONG_LIST_JOBS’ (‘-R’)

     Print job notifications in the long format by default.

‘MONITOR’ (‘-m’, ksh: ‘-m’)

     Allow job control.  Set by default in interactive shells.

‘NOTIFY’ (‘-5’, ksh: ‘-b’) <Z>

     Report the status of background jobs immediately, rather than
     waiting until just before printing a prompt.

‘POSIX_JOBS’ <K> <S>

     This option makes job control more compliant with the POSIX
     standard.

     When the option is not set, the ‘MONITOR’ option is unset on entry
     to subshells, so that job control is no longer active.  When the
     option is set, the ‘MONITOR’ option and job control remain active
     in the subshell, but note that the subshell has no access to jobs
     in the parent shell.

     When the option is not set, jobs put in the background or
     foreground with ‘bg’ or ‘fg’ are displayed with the same
     information that would be reported by ‘jobs’.  When the option is
     set, only the text is printed.  The output from ‘jobs’ itself is
     not affected by the option.

     When the option is not set, job information from the parent shell
     is saved for output within a subshell (for example, within a
     pipeline).  When the option is set, the output of ‘jobs’ is empty
     until a job is started within the subshell.

     In previous versions of the shell, it was necessary to enable
     ‘POSIX_JOBS’ in order for the builtin command ‘wait’ to return the
     status of background jobs that had already exited.  This is no
     longer the case.


File: zsh.info,  Node: Prompting,  Next: Scripts and Functions,  Prev: Job Control,  Up: Description of Options

15.2.8 Prompting
----------------

‘PROMPT_BANG’ <K>

     If set, ‘!’ is treated specially in prompt expansion.  See *note
     Expansion of Prompt Sequences: a7.

‘PROMPT_CR’ (‘+V’) <D>

     Print a carriage return just before printing a prompt in the line
     editor.  This is on by default as multi-line editing is only
     possible if the editor knows where the start of the line appears.

‘PROMPT_SP’ <D>

     Attempt to preserve a partial line (i.e.  a line that did not end
     with a newline) that would otherwise be covered up by the command
     prompt due to the ‘PROMPT_CR’ option.  This works by outputting
     some cursor-control characters, including a series of spaces, that
     should make the terminal wrap to the next line when a partial line
     is present (note that this is only successful if your terminal has
     automatic margins, which is typical).

     When a partial line is preserved, by default you will see an
     inverse+bold character at the end of the partial line: a ‘%’ for a
     normal user or a ‘#’ for root.  If set, the shell parameter
     ‘PROMPT_EOL_MARK’ can be used to customize how the end of partial
     lines are shown.

     NOTE: if the ‘PROMPT_CR’ option is not set, enabling this option
     will have no effect.  This option is on by default.

‘PROMPT_PERCENT’ <C> <Z>

     If set, ‘%’ is treated specially in prompt expansion.  See *note
     Expansion of Prompt Sequences: a7.

‘PROMPT_SUBST’ <K> <S>

     If set, ‘parameter expansion’, ‘command substitution’ and
     ‘arithmetic expansion’ are performed in prompts.  Substitutions
     within prompts do not affect the command status.

‘TRANSIENT_RPROMPT’

     Remove any right prompt from display when accepting a command line.
     This may be useful with terminals with other cut/paste methods.


File: zsh.info,  Node: Scripts and Functions,  Next: Shell Emulation,  Prev: Prompting,  Up: Description of Options

15.2.9 Scripts and Functions
----------------------------

‘ALIAS_FUNC_DEF’ <S>

     By default, zsh does not allow the definition of functions using
     the NAME ‘()’ syntax if NAME was expanded as an alias: this causes
     an error.  This is usually the desired behaviour, as otherwise the
     combination of an alias and a function based on the same definition
     can easily cause problems.

     When this option is set, aliases can be used for defining
     functions.

     For example, consider the following definitions as they might occur
     in a startup file.

           alias foo=bar
           foo() {
             print This probably does not do what you expect.
           }

     Here, ‘foo’ is expanded as an alias to ‘bar’ before the ‘()’ is
     encountered, so the function defined would be named ‘bar’.  By
     default this is instead an error in native mode.  Note that quoting
     any part of the function name, or using the keyword ‘function’,
     avoids the problem, so is recommended when the function name can
     also be an alias.

‘C_BASES’

     Output hexadecimal numbers in the standard C format, for example
     ‘0xFF’ instead of the usual ‘16#FF’.  If the option ‘OCTAL_ZEROES’
     is also set (it is not by default), octal numbers will be treated
     similarly and hence appear as ‘077’ instead of ‘8#77’.  This option
     has no effect on the choice of the output base, nor on the output
     of bases other than hexadecimal and octal.  Note that these formats
     will be understood on input irrespective of the setting of
     ‘C_BASES’.

‘C_PRECEDENCES’

     This alters the precedence of arithmetic operators to be more like
     C and other programming languages; *note Arithmetic Evaluation: a9.
     has an explicit list.

‘DEBUG_BEFORE_CMD’ <D>

     Run the ‘DEBUG’ trap before each command; otherwise it is run after
     each command.  Setting this option mimics the behaviour of ksh 93;
     with the option unset the behaviour is that of ksh 88.

‘ERR_EXIT’ (‘-e’, ksh: ‘-e’)

     If a command has a non-zero exit status, execute the ‘ZERR’ trap,
     if set, and exit.

     The option is ignored when executing the commands following
     ‘while’, ‘until’, ‘if’, or ‘elif’, a pipeline beginning with ‘!’,
     or any command other than the last in command list containing ‘&&’
     or ‘||’.  Hence neither ‘if foo; then true; fi’, nor ‘foo && true
     ``trigger exit when’ foo‘‘ returns with a non-zero exit status.
     Note that if ‘foo’ is a function, the option is also ignored during
     its whole execution.

     The option is also ignored when executing a complex command (‘if’,
     ‘for’, ‘while’, ‘until’, ‘repeat’, ‘case’, ‘select’, ‘always’, or a
     list in braces) if its exit status comes from a command executed
     while the option is ignored.  Hence, the ‘if’ command in ‘if true;
     then false && true; fi’ does not trigger exit.

     Finally, the option is also ignored while running initialization
     scripts and inside ‘DEBUG’ traps.  In the latter case, the option
     is handled specially: it is unset on entry to the trap.  If the
     option ‘DEBUG_BEFORE_CMD’ is set, as it is by default, and the
     option ‘ERR_EXIT’ is found to have been set on exit, then the
     command for which the ‘DEBUG’ trap is being executed is skipped.
     The option is restored after the trap exits.

     Exiting due to ‘ERR_EXIT’ has certain interactions with
     asynchronous jobs noted in *note Signals: aa.

     Note this behaviour is not disabled in interactive shells — a
     non-zero status on the command line causes the shell to exit.

‘ERR_RETURN’

     If a command has a non-zero exit status, return immediately from
     the enclosing function.  Except as explained below, an implicit
     ‘return’ statement is executed following the same logic described
     for ‘ERR_EXIT’.  This will trigger an exit at the outermost level
     of a non-interactive script.  At the top level of an interactive
     shell, it will trigger a return to the command prompt; in other
     words, the sequence of commands typed by the user may be thought of
     as a function for this purpose.

     Unlike for ‘ERR_EXIT’, when a function is called while the option
     is being ignored, the option is NOT ignored during the execution of
     the function.  Hence, if ‘foo’ in ‘foo && true’ is a function, code
     inside it is considered separately: it may force a return from
     ‘foo’ (assuming the option remains set within ‘foo’).

     Like for ‘ERR_EXIT’, the option is ignored inside ‘DEBUG’ traps but
     it’s not unset on entry to the trap and setting or unsetting it
     inside the trap has no special effect.

     If ‘ERR_RETURN’ and ‘ERR_EXIT’ are both set, it may happen that
     both exit and return should be triggered.  In that case only exit
     is triggered.

‘EVAL_LINENO’ <Z>

     If set, line numbers of expressions evaluated using the builtin
     ‘eval’ are tracked separately of the enclosing environment.  This
     applies both to the parameter ‘LINENO’ and the line number output
     by the prompt escape ‘%i’.  If the option is set, the prompt escape
     ‘%N’ will output the string ‘(eval)’ instead of the script or
     function name as an indication.  (The two prompt escapes are
     typically used in the parameter ‘PS4’ to be output when the option
     ‘XTRACE’ is set.)  If ‘EVAL_LINENO’ is unset, the line number of
     the surrounding script or function is retained during the
     evaluation.

‘EXEC’ (‘+n’, ksh: ‘+n’) <D>

     Do execute commands.  Without this option, commands are read and
     checked for syntax errors, but not executed.  This option cannot be
     turned off in an interactive shell, except when ‘-n’ is supplied to
     the shell at startup.

‘FUNCTION_ARGZERO’ <C> <Z>

     When executing a shell function or sourcing a script, set ‘$0’
     temporarily to the name of the function/script.  Note that toggling
     ‘FUNCTION_ARGZERO’ from on to off (or off to on) does not change
     the current value of ‘$0’.  Only the state upon entry to the
     function or script has an effect.  Compare ‘POSIX_ARGZERO’.

‘LOCAL_LOOPS’

     When this option is not set, the effect of ‘break’ and ‘continue’
     commands may propagate outside function scope, affecting loops in
     calling functions.  When the option is set in a calling function, a
     ‘break’ or a ‘continue’ that is not caught within a called function
     (regardless of the setting of the option within that function)
     produces a warning and the effect is cancelled.

‘LOCAL_OPTIONS’ <K>

     If this option is set at the point of return from a shell function,
     most options (including this one) which were in force upon entry to
     the function are restored; the ‘PRIVILEGED’ option is not restored.
     Otherwise, only this option, and the ‘LOCAL_LOOPS’, ‘XTRACE’ and
     ‘PRINT_EXIT_VALUE’ options are restored.  Hence if this is
     explicitly unset by a shell function the other options in force at
     the point of return will remain so.  A shell function can also
     guarantee itself a known shell configuration with a formulation
     like ‘emulate -L zsh’; the ‘-L’ activates ‘LOCAL_OPTIONS’.

‘LOCAL_PATTERNS’

     If this option is set at the point of return from a shell function,
     the state of pattern disables, as set with the builtin command
     ‘disable -p’, is restored to what it was when the function was
     entered.  The behaviour of this option is similar to the effect of
     ‘LOCAL_OPTIONS’ on options; hence ‘emulate -L sh’ (or indeed any
     other emulation with the ‘-L’ option) activates ‘LOCAL_PATTERNS’.

‘LOCAL_TRAPS’ <K>

     If this option is set when a signal trap is set inside a function,
     then the previous status of the trap for that signal will be
     restored when the function exits.  Note that this option must be
     set ‘prior’ to altering the trap behaviour in a function; unlike
     ‘LOCAL_OPTIONS’, the value on exit from the function is irrelevant.
     However, it does not need to be set before any global trap for that
     to be correctly restored by a function.  For example,

           unsetopt localtraps
           trap - INT
           fn() { setopt localtraps; trap '' INT; sleep 3; }

     will restore normal handling of ‘SIGINT’ after the function exits.

‘MULTI_FUNC_DEF’ <Z>

     Allow definitions of multiple functions at once in the form ‘fn1
     fn2’…‘‘()‘‘; if the option is not set, this causes a parse error.
     Definition of multiple functions with the ‘function’ keyword is
     always allowed.  Multiple function definitions are not often used
     and can cause obscure errors.

     Note that no error is raised if multiple functions are defined as a
     result of a set of names that were originally read as a single word
     on the command line, for example ‘TRAP{INT,QUIT}’.  Although there
     are no plans to change this behaviour at present, it is not
     guaranteed.

‘MULTIOS’ <Z>

     Perform implicit ‘tee’s or ‘cat’s when multiple redirections are
     attempted (see *note Redirection: ab.).

‘OCTAL_ZEROES’ <S>

     Interpret any integer constant beginning with a 0 as octal, per
     IEEE Std 1003.2-1992 (ISO 9945-2:1993).  This is not enabled by
     default as it causes problems with parsing of, for example, date
     and time strings with leading zeroes.

     Sequences of digits indicating a numeric base such as the ‘08’
     component in ‘08#77’ are always interpreted as decimal, regardless
     of leading zeroes.

‘PIPE_FAIL’

     By default, when a pipeline exits the exit status recorded by the
     shell and returned by the shell variable ‘$?’ reflects that of the
     rightmost element of a pipeline.  If this option is set, the exit
     status instead reflects the status of the rightmost element of the
     pipeline that was non-zero, or zero if all elements exited with
     zero status.

‘SOURCE_TRACE’

     If set, zsh will print an informational message announcing the name
     of each file it loads.  The format of the output is similar to that
     for the ‘XTRACE’ option, with the message ‘<sourcetrace>’.  A file
     may be loaded by the shell itself when it starts up and shuts down
     (‘Startup/Shutdown Files’) or by the use of the ‘source’ and ‘dot’
     builtin commands.

‘TYPESET_SILENT’

     If this is unset, executing any of the ‘typeset’ family of commands
     with no options and a list of parameters that have no values to be
     assigned but already exist will display the value of the parameter.
     If the option is set, they will only be shown when parameters are
     selected with the ‘-m’ option.  The option ‘-p’ is available
     whether or not the option is set.

‘TYPESET_TO_UNSET’ <K> <S>

     When declaring a new parameter with any of the ‘typeset’ family of
     related commands, the parameter remains unset unless and until a
     value is explicitly assigned to it, either in the ‘typeset’ command
     itself or as a later assignment statement.

‘VERBOSE’ (‘-v’, ksh: ‘-v’)

     Print shell input lines as they are read.

‘XTRACE’ (‘-x’, ksh: ‘-x’)

     Print commands and their arguments as they are executed.  The
     output is preceded by the value of ‘$PS4’, formatted as described
     in *note Expansion of Prompt Sequences: a7.


File: zsh.info,  Node: Shell Emulation,  Next: Shell State<2>,  Prev: Scripts and Functions,  Up: Description of Options

15.2.10 Shell Emulation
-----------------------

‘APPEND_CREATE’ <K> <S>

     This option only applies when ‘NO_CLOBBER’ (-‘C’) is in effect.

     If this option is not set, the shell will report an error when a
     append redirection (‘>>’) is used on a file that does not already
     exists (the traditional zsh behaviour of ‘NO_CLOBBER’).  If the
     option is set, no error is reported (POSIX behaviour).

‘BASH_REMATCH’

     When set, matches performed with the ‘=~’ operator will set the
     ‘BASH_REMATCH’ array variable, instead of the default ‘MATCH’ and
     ‘match’ variables.  The first element of the ‘BASH_REMATCH’ array
     will contain the entire matched text and subsequent elements will
     contain extracted substrings.  This option makes more sense when
     ‘KSH_ARRAYS’ is also set, so that the entire matched portion is
     stored at index 0 and the first substring is at index 1.  Without
     this option, the ‘MATCH’ variable contains the entire matched text
     and the ‘match’ array variable contains substrings.

‘BSD_ECHO’ <S>

     Make the ‘echo’ builtin compatible with the BSD ‘echo(1)’ command.
     This disables backslashed escape sequences in echo strings unless
     the ‘-e’ option is specified.

‘CONTINUE_ON_ERROR’

     If a fatal error is encountered (see *note Errors: ad.), and the
     code is running in a script, the shell will resume execution at the
     next statement in the script at the top level, in other words
     outside all functions or shell constructs such as loops and
     conditions.  This mimics the behaviour of interactive shells, where
     the shell returns to the line editor to read a new command; it was
     the normal behaviour in versions of zsh before 5.0.1.

‘CSH_JUNKIE_HISTORY’ <C>

     A history reference without an event specifier will always refer to
     the previous command.  Without this option, such a history
     reference refers to the same event as the previous history
     reference on the current command line, defaulting to the previous
     command.

‘CSH_JUNKIE_LOOPS’ <C>

     Allow loop bodies to take the form LIST‘; end’ instead of ‘do’
     LIST‘; done’.

‘CSH_JUNKIE_QUOTES’ <C>

     Changes the rules for single- and double-quoted text to match that
     of ‘csh’.  These require that embedded newlines be preceded by a
     backslash; unescaped newlines will cause an error message.  In
     double-quoted strings, it is made impossible to escape ‘$’, ‘`\’‘’
     or ‘"’ (and ‘\’ itself no longer needs escaping).  Command
     substitutions are only expanded once, and cannot be nested.

‘CSH_NULLCMD’ <C>

     Do not use the values of ‘NULLCMD’ and ‘READNULLCMD’ when running
     redirections with no command.  This make such redirections fail
     (see *note Redirection: ab.).

‘KSH_ARRAYS’ <K> <S>

     Emulate ‘ksh’ array handling as closely as possible.  If this
     option is set, array elements are numbered from zero, an array
     parameter without subscript refers to the first element instead of
     the whole array, and braces are required to delimit a subscript
     (‘${path[2]}’ rather than just ‘$path[2]’) or to apply modifiers to
     any parameter (‘${PWD:h}’ rather than ‘$PWD:h’).

‘KSH_AUTOLOAD’ <K> <S>

     Emulate ‘ksh’ function autoloading.  This means that when a
     function is autoloaded, the corresponding file is merely executed,
     and must define the function itself.  (By default, the function is
     defined to the contents of the file.  However, the most common
     ‘ksh’-style case - of the file containing only a simple definition
     of the function - is always handled in the ‘ksh’-compatible
     manner.)

‘KSH_OPTION_PRINT’ <K>

     Alters the way options settings are printed: instead of separate
     lists of set and unset options, all options are shown, marked ‘on’
     if they are in the non-default state, ‘off’ otherwise.

‘KSH_TYPESET’

     This option is now obsolete: a better approximation to the
     behaviour of other shells is obtained with the reserved word
     interface to ‘declare’, ‘export’, ‘float’, ‘integer’, ‘local’,
     ‘readonly’ and ‘typeset’.  Note that the option is only applied
     when the reserved word interface is ‘not’ in use.

     Alters the way arguments to the ‘typeset’ family of commands,
     including ‘declare’, ‘export’, ‘float’, ‘integer’, ‘local’ and
     ‘readonly’, are processed.  Without this option, zsh will perform
     normal word splitting after command and parameter expansion in
     arguments of an assignment; with it, word splitting does not take
     place in those cases.

‘KSH_ZERO_SUBSCRIPT’

     Treat use of a subscript of value zero in array or string
     expressions as a reference to the first element, i.e.  the element
     that usually has the subscript 1.  Ignored if ‘KSH_ARRAYS’ is also
     set.

     If neither this option nor ‘KSH_ARRAYS’ is set, accesses to an
     element of an array or string with subscript zero return an empty
     element or string, while attempts to set element zero of an array
     or string are treated as an error.  However, attempts to set an
     otherwise valid subscript range that includes zero will succeed.
     For example, if ‘KSH_ZERO_SUBSCRIPT’ is not set,

           array[0]=(element)

     is an error, while

           array[0,1]=(element)

     is not and will replace the first element of the array.

     This option is for compatibility with older versions of the shell
     and is not recommended in new code.

‘POSIX_ALIASES’ <K> <S>

     When this option is set, reserved words are not candidates for
     alias expansion: it is still possible to declare any of them as an
     alias, but the alias will never be expanded.  Reserved words are
     described in *note Reserved Words: ae.

     Alias expansion takes place while text is being read; hence when
     this option is set it does not take effect until the end of any
     function or other piece of shell code parsed as one unit.  Note
     this may cause differences from other shells even when the option
     is in effect.  For example, when running a command with ‘zsh -c’,
     or even ‘zsh -o posixaliases -c’, the entire command argument is
     parsed as one unit, so aliases defined within the argument are not
     available even in later lines.  If in doubt, avoid use of aliases
     in non-interactive code.

‘POSIX_ARGZERO’

     This option may be used to temporarily disable ‘FUNCTION_ARGZERO’
     and thereby restore the value of ‘$0’ to the name used to invoke
     the shell (or as set by the ‘-c’ command line option).  For
     compatibility with previous versions of the shell, emulations use
     ‘NO_FUNCTION_ARGZERO’ instead of ‘POSIX_ARGZERO’, which may result
     in unexpected scoping of ‘$0’ if the emulation mode is changed
     inside a function or script.  To avoid this, explicitly enable
     ‘POSIX_ARGZERO’ in the ‘emulate’ command:

           emulate sh -o POSIX_ARGZERO

     Note that ‘NO_POSIX_ARGZERO’ has no effect unless
     ‘FUNCTION_ARGZERO’ was already enabled upon entry to the function
     or script.

‘POSIX_BUILTINS’ <K> <S>

     When this option is set the ‘command’ builtin can be used to
     execute shell builtin commands.  Parameter assignments specified
     before shell functions and special builtins are kept after the
     command completes unless the special builtin is prefixed with the
     ‘command’ builtin.  Special builtins are ‘.’, ‘:’, ‘break’,
     ‘continue’, ‘declare’, ‘eval’, ‘exit’, ‘export’, ‘integer’,
     ‘local’, ‘readonly’, ‘return’, ‘set’, ‘shift’, ‘source’, ‘times’,
     ‘trap’ and ‘unset’.

     In addition, various error conditions associated with the above
     builtins or ‘exec’ cause a non-interactive shell to exit and an
     interactive shell to return to its top-level processing.

     Furthermore, functions and shell builtins are not executed after an
     ‘exec’ prefix; the command to be executed must be an external
     command found in the path.

     Moreover, the warning and special exit code from ‘[[ -o’
     NON_EXISTENT_OPTION ‘]]’ are suppressed.

     Other builtins may be affected as described in

     Shell Builtin Commands

     .

‘POSIX_IDENTIFIERS’ <K> <S>

     When this option is set, only the ASCII characters ‘a’ to ‘z’, ‘A’
     to ‘Z’, ‘0’ to ‘9’ and ‘_’ may be used in identifiers (names of
     shell parameters and modules).

     In addition, setting this option limits the effect of parameter
     substitution with no braces, so that the expression ‘$#’ is treated
     as the parameter ‘$#’ even if followed by a valid parameter name.
     When it is unset, zsh allows expressions of the form ‘$#’NAME to
     refer to the length of ‘$’NAME, even for special variables, for
     example in expressions such as ‘$#-’ and ‘$#*’.

     Another difference is that with the option set assignment to an
     unset variable in arithmetic context causes the variable to be
     created as a scalar rather than a numeric type.  So after ‘unset t;
     (( t = 3 ))’, without‘‘ POSIX_IDENTIFIERS ‘set’ t‘‘ has integer
     type, while with it set it has scalar type.

     When the option is unset and multibyte character support is enabled
     (i.e.  it is compiled in and the option ‘MULTIBYTE’ is set), then
     additionally any alphanumeric characters in the local character set
     may be used in identifiers.  Note that scripts and functions
     written with this feature are not portable, and also that both
     options must be set before the script or function is parsed;
     setting them during execution is not sufficient as the syntax
     VARIABLE‘=’VALUE has already been parsed as a command rather than
     an assignment.

     If multibyte character support is not compiled into the shell this
     option is ignored; all octets with the top bit set may be used in
     identifiers.  This is non-standard but is the traditional zsh
     behaviour.

‘POSIX_STRINGS’ <K> <S>

     This option affects processing of quoted strings.  Currently it
     only affects the behaviour of null characters, i.e.  character 0 in
     the portable character set corresponding to US ASCII.

     When this option is not set, null characters embedded within
     strings of the form ‘$'’…‘'’ are treated as ordinary characters.
     The entire string is maintained within the shell and output to
     files where necessary, although owing to restrictions of the
     library interface the string is truncated at the null character in
     file names, environment variables, or in arguments to external
     programs.

     When this option is set, the ‘$'’…‘'’ expression is truncated at
     the null character.  Note that remaining parts of the same string
     beyond the termination of the quotes are not truncated.

     For example, the command line argument ‘a$'b\0c'd’ is treated with
     the option off as the characters ‘a’, ‘b’, null, ‘c’, ‘d’, and with
     the option on as the characters ‘a’, ‘b’, ‘d’.

‘POSIX_TRAPS’ <K> <S>

     When this option is set, the usual zsh behaviour of executing traps
     for ‘EXIT’ on exit from shell functions is suppressed.  In that
     case, manipulating ‘EXIT’ traps always alters the global trap for
     exiting the shell; the ‘LOCAL_TRAPS’ option is ignored for the
     ‘EXIT’ trap.

     Also, a ‘return’ statement executed in a trap with no argument
     passes back from the function the value from the surrounding
     context, not from code executed within the trap.

     Furthermore, if a trap is set to be ignored, this state persists
     when a subshell is entered.  Without the option, the trap would be
     reset to its default state at this point.

‘SH_FILE_EXPANSION’ <K> <S>

     Perform filename expansion (e.g., ‘~’ expansion) ‘before’ parameter
     expansion, command substitution, arithmetic expansion and brace
     expansion.  If this option is unset, it is performed ‘after’ brace
     expansion, so things like ‘~$USERNAME’ and ‘~{pfalstad,rc}’ will
     work.

‘SH_NULLCMD’ <K> <S>

     Do not use the values of ‘NULLCMD’ and ‘READNULLCMD’ when doing
     redirections, use ‘:’ instead (see *note Redirection: ab.).

‘SH_OPTION_LETTERS’ <K> <S>

     If this option is set the shell tries to interpret single letter
     options (which are used with ‘set’ and ‘setopt’) like ‘ksh’ does.
     This also affects the value of the ‘-’ special parameter.

‘SH_WORD_SPLIT’ (‘-y’) <K> <S>

     Causes field splitting to be performed on unquoted parameter
     expansions.  Note that this option has nothing to do with word
     splitting.  (See *note Parameter Expansion: 1a.)

‘TRAPS_ASYNC’

     While waiting for a program to exit, handle signals and run traps
     immediately.  Otherwise the trap is run after a child process has
     exited.  Note this does not affect the point at which traps are run
     for any case other than when the shell is waiting for a child
     process.


File: zsh.info,  Node: Shell State<2>,  Next: Zle,  Prev: Shell Emulation,  Up: Description of Options

15.2.11 Shell State
-------------------

‘INTERACTIVE’ (‘-i’, ksh: ‘-i’)

     This is an interactive shell.  This option is set upon
     initialisation if the standard input is a tty and commands are
     being read from standard input.  (See the discussion of
     ‘SHIN_STDIN’.)  This heuristic may be overridden by specifying a
     state for this option on the command line.  The value of this
     option can only be changed via flags supplied at invocation of the
     shell.  It cannot be changed once zsh is running.

‘LOGIN’ (‘-l’, ksh: ‘-l’)

     This is a login shell.  If this option is not explicitly set, the
     shell becomes a login shell if the first character of the ‘argv[0]’
     passed to the shell is a ‘-’.

‘PRIVILEGED’ (‘-p’, ksh: ‘-p’)

     Turn on privileged mode.  Typically this is used when script is to
     be run with elevated privileges.  This should be done as follows
     directly with the ‘-p’ option to zsh so that it takes effect during
     startup.

           #!/bin/zsh -p

     The option is enabled automatically on startup if the effective
     user (group) ID is not equal to the real user (group) ID. In this
     case, turning the option off causes the effective user and group
     IDs to be set to the real user and group IDs.  Be aware that if
     that fails the shell may be running with different IDs than was
     intended so a script should check for failure and act accordingly,
     for example:

           unsetopt privileged || exit

     The ‘PRIVILEGED’ option disables sourcing user startup files.  If
     zsh is invoked as ‘sh’ or ‘ksh’ with this option set,
     ‘/etc/suid_profile’ is sourced (after ‘/etc/profile’ on interactive
     shells).  Sourcing ‘~/.profile’ is disabled and the contents of the
     ‘ENV’ variable is ignored.  This option cannot be changed using the
     ‘-m’ option of ‘setopt’ and ‘unsetopt’, and changing it inside a
     function always changes it globally regardless of the
     ‘LOCAL_OPTIONS’ option.

‘SHIN_STDIN’ (‘-s’, ksh: ‘-s’)

     Commands are being read from the standard input.  Commands are read
     from standard input if no command is specified with ‘-c’ and no
     file of commands is specified.  If ‘SHIN_STDIN’ is set explicitly
     on the command line, any argument that would otherwise have been
     taken as a file to run will instead be treated as a normal
     positional parameter.  Note that setting or unsetting this option
     on the command line does not necessarily affect the state the
     option will have while the shell is running - that is purely an
     indicator of whether or not commands are ‘actually’ being read from
     standard input.  The value of this option can only be changed via
     flags supplied at invocation of the shell.  It cannot be changed
     once zsh is running.

‘SINGLE_COMMAND’ (‘-t’, ksh: ‘-t’)

     If the shell is reading from standard input, it exits after a
     single command has been executed.  This also makes the shell
     non-interactive, unless the ‘INTERACTIVE’ option is explicitly set
     on the command line.  The value of this option can only be changed
     via flags supplied at invocation of the shell.  It cannot be
     changed once zsh is running.


File: zsh.info,  Node: Zle,  Prev: Shell State<2>,  Up: Description of Options

15.2.12 Zle
-----------

‘BEEP’ (‘+B’) <D>

     Beep on error in ZLE.

‘COMBINING_CHARS’

     Assume that the terminal displays combining characters correctly.
     Specifically, if a base alphanumeric character is followed by one
     or more zero-width punctuation characters, assume that the
     zero-width characters will be displayed as modifications to the
     base character within the same width.  Not all terminals handle
     this.  If this option is not set, zero-width characters are
     displayed separately with special mark-up.

     If this option is set, the pattern test ‘[[:WORD:]]’ matches a
     zero-width punctuation character on the assumption that it will be
     used as part of a word in combination with a word character.
     Otherwise the base shell does not handle combining characters
     specially.

‘EMACS’

     If ZLE is loaded, turning on this option has the equivalent effect
     of ‘bindkey -e’.  In addition, the ‘VI’ option is unset.  Turning
     it off has no effect.  The option setting is not guaranteed to
     reflect the current keymap, and the ‘LOCALOPTIONS’ option does not
     work correctly.  This option is provided only for compatibility,
     and its use is highly discouraged.  ‘bindkey’ is the recommended
     interface.

‘OVERSTRIKE’

     Start up the line editor in overstrike mode.

‘SINGLE_LINE_ZLE’ (‘-M’) <K>

     Use single-line command line editing instead of multi-line.

     Note that although this is on by default in ksh emulation it only
     provides superficial compatibility with the ksh line editor and
     reduces the effectiveness of the zsh line editor.  As it has no
     effect on shell syntax, many users may wish to disable this option
     when using ksh emulation interactively.

‘VI’

     If ZLE is loaded, turning on this option has the equivalent effect
     of ‘bindkey -v’.  In addition, the ‘EMACS’ option is unset.
     Turning it off has no effect.  The option setting is not guaranteed
     to reflect the current keymap, and the ‘LOCALOPTIONS’ option does
     not work correctly.  This option is provided only for
     compatibility, and its use is highly discouraged.  ‘bindkey’ is the
     recommended interface.

‘ZLE’ (‘-Z’)

     Use the zsh line editor.  Set by default in interactive shells
     connected to a terminal.


File: zsh.info,  Node: Option Aliases,  Next: Single Letter Options,  Prev: Description of Options,  Up: Options<2>

15.3 Option Aliases
===================

Some options have alternative names.  These aliases are never used for
output, but can be used just like normal option names when specifying
options to the shell.

‘BRACE_EXPAND’

     ‘NO_’‘IGNORE_BRACES’ (ksh and bash compatibility)

‘DOT_GLOB’

     ‘GLOB_DOTS’ (bash compatibility)

‘HASH_ALL’

     ‘HASH_CMDS’ (bash compatibility)

‘HIST_APPEND’

     ‘APPEND_HISTORY’ (bash compatibility)

‘HIST_EXPAND’

     ‘BANG_HIST’ (bash compatibility)

‘LOG’

     ‘NO_’‘HIST_NO_FUNCTIONS’ (ksh compatibility)

‘MAIL_WARN’

     ‘MAIL_WARNING’ (bash compatibility)

‘ONE_CMD’

     ‘SINGLE_COMMAND’ (bash compatibility)

‘PHYSICAL’

     ‘CHASE_LINKS’ (ksh and bash compatibility)

‘PROMPT_VARS’

     ‘PROMPT_SUBST’ (bash compatibility)

‘STDIN’

     ‘SHIN_STDIN’ (ksh compatibility)

‘TRACK_ALL’

     ‘HASH_CMDS’ (ksh compatibility)


File: zsh.info,  Node: Single Letter Options,  Prev: Option Aliases,  Up: Options<2>

15.4 Single Letter Options
==========================

* Menu:

* Default Set::
* sh/ksh Emulation Set::
* Also Note::


File: zsh.info,  Node: Default Set,  Next: sh/ksh Emulation Set,  Up: Single Letter Options

15.4.1 Default Set
------------------

‘-0’

     CORRECT

‘-1’

     PRINT_EXIT_VALUE

‘-2’

     ‘NO_’BAD_PATTERN

‘-3’

     ‘NO_’NOMATCH

‘-4’

     GLOB_DOTS

‘-5’

     NOTIFY

‘-6’

     BG_NICE

‘-7’

     IGNORE_EOF

‘-8’

     MARK_DIRS

‘-9’

     AUTO_LIST

‘-B’

     ‘NO_’BEEP

‘-C’

     ‘NO_’CLOBBER

‘-D’

     PUSHD_TO_HOME

‘-E’

     PUSHD_SILENT

‘-F’

     ‘NO_’GLOB

‘-G’

     NULL_GLOB

‘-H’

     RM_STAR_SILENT

‘-I’

     IGNORE_BRACES

‘-J’

     AUTO_CD

‘-K’

     ‘NO_’BANG_HIST

‘-L’

     SUN_KEYBOARD_HACK

‘-M’

     SINGLE_LINE_ZLE

‘-N’

     AUTO_PUSHD

‘-O’

     CORRECT_ALL

‘-P’

     RC_EXPAND_PARAM

‘-Q’

     PATH_DIRS

‘-R’

     LONG_LIST_JOBS

‘-S’

     REC_EXACT

‘-T’

     CDABLE_VARS

‘-U’

     MAIL_WARNING

‘-V’

     ‘NO_’PROMPT_CR

‘-W’

     AUTO_RESUME

‘-X’

     LIST_TYPES

‘-Y’

     MENU_COMPLETE

‘-Z’

     ZLE

‘-a’

     ALL_EXPORT

‘-e’

     ERR_EXIT

‘-f’

     ‘NO_’RCS

‘-g’

     HIST_IGNORE_SPACE

‘-h’

     HIST_IGNORE_DUPS

‘-i’

     INTERACTIVE

‘-k’

     INTERACTIVE_COMMENTS

‘-l’

     LOGIN

‘-m’

     MONITOR

‘-n’

     ‘NO_’EXEC

‘-p’

     PRIVILEGED

‘-r’

     RESTRICTED

‘-s’

     SHIN_STDIN

‘-t’

     SINGLE_COMMAND

‘-u’

     ‘NO_’UNSET

‘-v’

     VERBOSE

‘-w’

     CHASE_LINKS

‘-x’

     XTRACE

‘-y’

     SH_WORD_SPLIT


File: zsh.info,  Node: sh/ksh Emulation Set,  Next: Also Note,  Prev: Default Set,  Up: Single Letter Options

15.4.2 sh/ksh Emulation Set
---------------------------

‘-C’

     ‘NO_’CLOBBER

‘-T’

     TRAPS_ASYNC

‘-X’

     MARK_DIRS

‘-a’

     ALL_EXPORT

‘-b’

     NOTIFY

‘-e’

     ERR_EXIT

‘-f’

     ‘NO_’GLOB

‘-i’

     INTERACTIVE

‘-l’

     LOGIN

‘-m’

     MONITOR

‘-n’

     ‘NO_’EXEC

‘-p’

     PRIVILEGED

‘-r’

     RESTRICTED

‘-s’

     SHIN_STDIN

‘-t’

     SINGLE_COMMAND

‘-u’

     ‘NO_’UNSET

‘-v’

     VERBOSE

‘-x’

     XTRACE


File: zsh.info,  Node: Also Note,  Prev: sh/ksh Emulation Set,  Up: Single Letter Options

15.4.3 Also Note
----------------

‘-A’

     Used by ‘set’ for setting arrays

‘-b’

     Used on the command line to specify end of option processing

‘-c’

     Used on the command line to specify a single command

‘-m’

     Used by ‘setopt’ for pattern-matching option setting

‘-o’

     Used in all places to allow use of long option names

‘-s’

     Used by ‘set’ to sort positional parameters


File: zsh.info,  Node: Shell Builtin Commands,  Next: Zsh Line Editor,  Prev: Options<2>,  Up: Top

16 Shell Builtin Commands
*************************

Some shell builtin commands take options as described in individual
entries; these are often referred to in the list below as ‘flags’ to
avoid confusion with shell options, which may also have an effect on the
behaviour of builtin commands.  In this introductory section, ‘option’
always has the meaning of an option to a command that should be familiar
to most command line users.

Typically, options are single letters preceded by a hyphen (‘-’).
Options that take an argument accept it either immediately following the
option letter or after white space, for example ‘print -C3 {1..9}’ or
‘print -C 3 {1..9}’ are equivalent.  Arguments to options are not the
same as arguments to the command; the documentation indicates which is
which.  Options that do not take an argument may be combined in a single
word, for example ‘print -rca -- *’ and ‘print -r -c -a -- *’ are
equivalent.

Some shell builtin commands also take options that begin with ‘+’
instead of ‘-’.  The list below makes clear which commands these are.

Options (together with their individual arguments, if any) must appear
in a group before any non-option arguments; once the first non-option
argument has been found, option processing is terminated.

All builtin commands other than ‘echo’ and precommand modifiers, even
those that have no options, can be given the argument ‘--’ to terminate
option processing.  This indicates that the following words are
non-option arguments, but is otherwise ignored.  This is useful in cases
where arguments to the command may begin with ‘-’.  For historical
reasons, most builtin commands (including ‘echo’) also recognize a
single ‘-’ in a separate word for this purpose; note that this is less
standard and use of ‘--’ is recommended.

‘-’ SIMPLE COMMAND

     See *note Precommand Modifiers: b7.

‘.’  FILE [ ARG … ]

     Read commands from FILE and execute them in the current shell
     environment.

     If FILE does not contain a slash, or if ‘PATH_DIRS’ is set, the
     shell looks in the components of ‘$path’ to find the directory
     containing FILE.  Files in the current directory are not read
     unless ‘.’ appears somewhere in ‘$path’.  If a file named
     FILE‘.zwc’ is found, is newer than FILE, and is the compiled form
     (created with the ‘zcompile’ builtin) of FILE, then commands are
     read from that file instead of FILE.

     If any arguments ARG are given, they become the positional
     parameters; the old positional parameters are restored when the
     FILE is done executing.  However, if no arguments are given, the
     positional parameters remain those of the calling context, and no
     restoring is done.

     If FILE was not found the return status is 127; if FILE was found
     but contained a syntax error the return status is 126; else the
     return status is the exit status of the last command executed.

‘:’ [ ARG … ]

     This command does nothing, although normal argument expansions is
     performed which may have effects on shell parameters.  A zero exit
     status is returned.

‘alias’ [ {‘+|-}gmrsL’ ] [ NAME[‘=’VALUE] … ]

     For each NAME with a corresponding VALUE, define an alias with that
     value.  A trailing space in VALUE causes the next word to be
     checked for alias expansion.  If the ‘-g’ flag is present, define a
     global alias; global aliases are expanded even if they do not occur
     in command position:

           % perldoc --help 2>&1 | grep 'built-in functions'
               -f   Search Perl built-in functions
           % alias -g HG='--help 2>&1 | grep'
           % perldoc HG 'built-in functions'
               -f   Search Perl built-in functions

     If the ‘-s’ flag is present, define a suffix alias: if the command
     word on a command line is in the form TEXT‘.’NAME, where TEXT is
     any non-empty string, it is replaced by the text VALUE TEXT‘.’NAME.
     Note that NAME is treated as a literal string, not a pattern.  A
     trailing space in VALUE is not special in this case.  For example,

           alias -s ps='gv --'

     will cause the command ‘*.ps’ to be expanded to ‘gv -- *.ps’.  As
     alias expansion is carried out earlier than globbing, the ‘*.ps’
     will then be expanded.  Suffix aliases constitute a different name
     space from other aliases (so in the above example it is still
     possible to create an alias for the command ‘ps’) and the two sets
     are never listed together.

     For each NAME with no VALUE, print the value of NAME, if any.  With
     no arguments, print all currently defined aliases other than suffix
     aliases.  If the ‘-m’ flag is given the arguments are taken as
     patterns (they should be quoted to preserve them from being
     interpreted as glob patterns), and the aliases matching these
     patterns are printed.  When printing aliases and one of the ‘-g’,
     ‘-r’ or ‘-s’ flags is present, restrict the printing to global,
     regular or suffix aliases, respectively; a regular alias is one
     which is neither a global nor a suffix alias.  Using ‘+’ instead of
     ‘-’, or ending the option list with a single ‘+’, prevents the
     values of the aliases from being printed.

     If the ‘-L’ flag is present, then print each alias in a manner
     suitable for putting in a startup script.  The exit status is
     nonzero if a NAME (with no VALUE) is given for which no alias has
     been defined.

     For more on aliases, including common problems, see *note Aliasing:
     b8.

‘autoload’ [ {‘+|-}RTUXdkmrtWz’ ] [ ‘-w’ ] [ NAME … ]

     See *note Autoloading Functions: b9. for full details.  The ‘fpath’
     parameter will be searched to find the function definition when the
     function is first referenced.

     If NAME consists of an absolute path, the function is defined to
     load from the file given (searching as usual for dump files in the
     given location).  The name of the function is the basename
     (non-directory part) of the file.  It is normally an error if the
     function is not found in the given location; however, if the option
     ‘-d’ is given, searching for the function defaults to ‘$fpath’.  If
     a function is loaded by absolute path, any functions loaded from it
     that are marked for ‘autoload’ without an absolute path have the
     load path of the parent function temporarily prepended to ‘$fpath’.

     If the option ‘-r’ or ‘-R’ is given, the function is searched for
     immediately and the location is recorded internally for use when
     the function is executed; a relative path is expanded using the
     value of ‘$PWD’.  This protects against a change to ‘$fpath’ after
     the call to ‘autoload’.  With ‘-r’, if the function is not found,
     it is silently left unresolved until execution; with ‘-R’, an error
     message is printed and command processing aborted immediately the
     search fails, i.e.  at the ‘autoload’ command rather than at
     function execution..

     The flag ‘-X’ may be used only inside a shell function.  It causes
     the calling function to be marked for autoloading and then
     immediately loaded and executed, with the current array of
     positional parameters as arguments.  This replaces the previous
     definition of the function.  If no function definition is found, an
     error is printed and the function remains undefined and marked for
     autoloading.  If an argument is given, it is used as a directory
     (i.e.  it does not include the name of the function) in which the
     function is to be found; this may be combined with the ‘-d’ option
     to allow the function search to default to ‘$fpath’ if it is not in
     the given location.

     The flag ‘+X’ attempts to load each NAME as an autoloaded function,
     but does ‘not’ execute it.  The exit status is zero (success) if
     the function was not previously defined ‘and’ a definition for it
     was found.  This does ‘not’ replace any existing definition of the
     function.  The exit status is nonzero (failure) if the function was
     already defined or when no definition was found.  In the latter
     case the function remains undefined and marked for autoloading.  If
     ksh-style autoloading is enabled, the function created will contain
     the contents of the file plus a call to the function itself
     appended to it, thus giving normal ksh autoloading behaviour on the
     first call to the function.  If the ‘-m’ flag is also given each
     NAME is treated as a pattern and all functions already marked for
     autoload that match the pattern are loaded.

     With the ‘-t’ flag, turn on execution tracing; with ‘-T’, turn on
     execution tracing only for the current function, turning it off on
     entry to any called functions that do not also have tracing
     enabled.

     With the ‘-U’ flag, alias expansion is suppressed when the function
     is loaded.

     With the ‘-w’ flag, the NAMEs are taken as names of files compiled
     with the ‘zcompile’ builtin, and all functions defined in them are
     marked for autoloading.

     The flags ‘-z’ and ‘-k’ mark the function to be autoloaded using
     the zsh or ksh style, as if the option ‘KSH_AUTOLOAD’ were unset or
     were set, respectively.  The flags override the setting of the
     option at the time the function is loaded.

     Note that the ‘autoload’ command makes no attempt to ensure the
     shell options set during the loading or execution of the file have
     any particular value.  For this, the ‘emulate’ command can be used:

           emulate zsh -c 'autoload -Uz FUNC'

     arranges that when FUNC is loaded the shell is in native ‘zsh’
     emulation, and this emulation is also applied when FUNC is run.

     Some of the functions of ‘autoload’ are also provided by ‘functions
     -u ``or’ functions -U‘‘, but‘‘ autoload‘‘ is a more comprehensive
     interface.

‘bg’ [ JOB … ]

JOB … ‘&’

     Put each specified JOB in the background, or the current job if
     none is specified.

‘bindkey’

     See *note Zle Builtins: ba.

‘break’ [ N ]

     Exit from an enclosing ‘for’, ‘while’, ‘until’, ‘select’ or
     ‘repeat’ loop.  If an arithmetic expression N is specified, then
     break N levels instead of just one.

‘builtin’ NAME [ ARGS … ]

     Executes the builtin NAME, with the given ARGS.

‘bye’

     Same as ‘exit’.

‘cap’

     See *note The zsh/cap Module: bb.

‘cd’ [ ‘-qsLP’ ] [ ARG ]

‘cd’ [ ‘-qsLP’ ] OLD NEW

‘cd’ [ ‘-qsLP’ ] {‘+|-’}:var:‘n’

     Change the current directory.  In the first form, change the
     current directory to ARG, or to the value of ‘$HOME’ if ARG is not
     specified.  If ARG is ‘-’, change to the previous directory.

     Otherwise, if ARG begins with a slash, attempt to change to the
     directory given by ARG.

     If ARG does not begin with a slash, the behaviour depends on
     whether the current directory ‘.’ occurs in the list of directories
     contained in the shell parameter ‘cdpath’.  If it does not, first
     attempt to change to the directory ARG under the current directory,
     and if that fails but ‘cdpath’ is set and contains at least one
     element attempt to change to the directory ARG under each component
     of ‘cdpath’ in turn until successful.  If ‘.’ occurs in ‘cdpath’,
     then ‘cdpath’ is searched strictly in order so that ‘.’ is only
     tried at the appropriate point.

     The order of testing ‘cdpath’ is modified if the option ‘POSIX_CD’
     is set, as described in the documentation for the option.

     If no directory is found, the option ‘CDABLE_VARS’ is set, and a
     parameter named ARG exists whose value begins with a slash, treat
     its value as the directory.  In that case, the parameter is added
     to the named directory hash table.

     The second form of ‘cd’ substitutes the string NEW for the string
     OLD in the name of the current directory, and tries to change to
     this new directory.

     The third form of ‘cd’ extracts an entry from the directory stack,
     and changes to that directory.  An argument of the form ‘+’N
     identifies a stack entry by counting from the left of the list
     shown by the ‘dirs’ command, starting with zero.  An argument of
     the form ‘-’N counts from the right.  If the ‘PUSHD_MINUS’ option
     is set, the meanings of ‘+’ and ‘-’ in this context are swapped.
     If the ‘POSIX_CD’ option is set, this form of ‘cd’ is not
     recognised and will be interpreted as the first form.

     If the ‘-q’ (quiet) option is specified, the hook function ‘chpwd’
     and the functions in the array ‘chpwd_functions’ are not called.
     This is useful for calls to ‘cd’ that do not change the environment
     seen by an interactive user.

     If the ‘-s’ option is specified, ‘cd’ refuses to change the current
     directory if the given pathname contains symlinks.  If the ‘-P’
     option is given or the ‘CHASE_LINKS’ option is set, symbolic links
     are resolved to their true values.  If the ‘-L’ option is given
     symbolic links are retained in the directory (and not resolved)
     regardless of the state of the ‘CHASE_LINKS’ option.

‘chdir’

     Same as ‘cd’.

‘clone’

     See *note The zsh/clone Module: bc.

‘command’ [ ‘-pvV’ ] SIMPLE COMMAND

     The simple command argument is taken as an external command instead
     of a function or builtin and is executed.  If the ‘POSIX_BUILTINS’
     option is set, builtins will also be executed but certain special
     properties of them are suppressed.  The ‘-p’ flag causes a default
     path to be searched instead of that in ‘$path’.  With the ‘-v’
     flag, ‘command’ is similar to ‘whence’ and with ‘-V’, it is
     equivalent to ‘whence -v’.

     See also *note Precommand Modifiers: b7.

‘comparguments’

     See *note The zsh/computil Module: bd.

‘compcall’

     See *note The zsh/compctl Module: be.

‘compctl’

     See *note The zsh/compctl Module: be.

‘compdescribe’

     See *note The zsh/computil Module: bd.

‘compfiles’

     See *note The zsh/computil Module: bd.

‘compgroups’

     See *note The zsh/computil Module: bd.

‘compquote’

     See *note The zsh/computil Module: bd.

‘comptags’

     See *note The zsh/computil Module: bd.

‘comptry’

     See *note The zsh/computil Module: bd.

‘compvalues’

     See *note The zsh/computil Module: bd.

‘continue’ [ N ]

     Resume the next iteration of the enclosing ‘for’, ‘while’, ‘until’,
     ‘select’ or ‘repeat’ loop.  If an arithmetic expression N is
     specified, break out of N-1 loops and resume at the Nth enclosing
     loop.

‘declare’

     Same as ‘typeset’.

‘dirs’ [ ‘-c’ ] [ ARG … ]

‘dirs’ [ ‘-lpv’ ]

     With no arguments, print the contents of the directory stack.
     Directories are added to this stack with the ‘pushd’ command, and
     removed with the ‘cd’ or ‘popd’ commands.  If arguments are
     specified, load them onto the directory stack, replacing anything
     that was there, and push the current directory onto the stack.

     ‘-c’

          clear the directory stack.

     ‘-l’

          print directory names in full instead of using ‘~’ expressions
          (see *note Filename Expansion: 5d.).

     ‘-p’

          print directory entries one per line.

     ‘-v’

          number the directories in the stack when printing.

‘disable’ [ ‘-afmprs’ ] NAME …

     Temporarily disable the NAMEd hash table elements or patterns.  The
     default is to disable builtin commands.  This allows you to use an
     external command with the same name as a builtin command.  The ‘-a’
     option causes ‘disable’ to act on regular or global aliases.  The
     ‘-s’ option causes ‘disable’ to act on suffix aliases.  The ‘-f’
     option causes ‘disable’ to act on shell functions.  The ‘-r’
     options causes ‘disable’ to act on reserved words.  Without
     arguments all disabled hash table elements from the corresponding
     hash table are printed.  With the ‘-m’ flag the arguments are taken
     as patterns (which should be quoted to prevent them from undergoing
     filename expansion), and all hash table elements from the
     corresponding hash table matching these patterns are disabled.
     Disabled objects can be enabled with the ‘enable’ command.

     With the option ‘-p’, NAME … refer to elements of the shell’s
     pattern syntax as described in *note Filename Generation: 17.
     Certain elements can be disabled separately, as given below.

     Note that patterns not allowed by the current settings for the
     options ‘EXTENDED_GLOB’, ‘KSH_GLOB’ and ‘SH_GLOB’ are never
     enabled, regardless of the setting here.  For example, if
     ‘EXTENDED_GLOB’ is not active, the pattern ‘^’ is ineffective even
     if ‘disable -p "^"’ has not been issued.  The list below indicates
     any option settings that restrict the use of the pattern.  It
     should be noted that setting ‘SH_GLOB’ has a wider effect than
     merely disabling patterns as certain expressions, in particular
     those involving parentheses, are parsed differently.

     The following patterns may be disabled; all the strings need
     quoting on the command line to prevent them from being interpreted
     immediately as patterns and the patterns are shown below in single
     quotes as a reminder.

     ‘'?'’

          The pattern character ‘?’ wherever it occurs, including when
          preceding a parenthesis with ‘KSH_GLOB’.

     ‘'*'’

          The pattern character ‘*’ wherever it occurs, including
          recursive globbing and when preceding a parenthesis with
          ‘KSH_GLOB’.

     ‘'['’

          Character classes.

     ‘'<'’ (‘NO_SH_GLOB’)

          Numeric ranges.

     ‘'|'’ (‘NO_SH_GLOB’)

          Alternation in grouped patterns, case statements, or KSH_GLOB
          parenthesised expressions.

     ‘'('’ (‘NO_SH_GLOB’)

          Grouping using single parentheses.  Disabling this does not
          disable the use of parentheses for ‘KSH_GLOB’ where they are
          introduced by a special character, nor for glob qualifiers
          (use ‘setopt NO_BARE_GLOB_QUAL’ to disable glob qualifiers
          that use parentheses only).

     ‘'~'’ (‘EXTENDED_GLOB’)

          Exclusion in the form A‘~’B.

     ‘'^'’ (‘EXTENDED_GLOB’)

          Exclusion in the form A‘^’B.

     ‘'#'’ (‘EXTENDED_GLOB’)

          The pattern character ‘#’ wherever it occurs, both for
          repetition of a previous pattern and for indicating globbing
          flags.

     ‘'?('’ (‘KSH_GLOB’)

          The grouping form ‘?(’…‘)’.  Note this is also disabled if
          ‘'?'’ is disabled.

     ‘'*('’ (‘KSH_GLOB’)

          The grouping form ‘*(’…‘)’.  Note this is also disabled if
          ‘'*'’ is disabled.

     ‘'+('’ (‘KSH_GLOB’)

          The grouping form ‘+(’…‘)’.

     ‘'!('’ (‘KSH_GLOB’)

          The grouping form ‘!(’…‘)’.

     ‘'@('’ (‘KSH_GLOB’)

          The grouping form ‘@(’…‘)’.

‘disown’ [ ‘-a’ | JOB … ]

JOB … ‘&|’

JOB … ‘&!’

     Remove the specified JOBs from the job table; the shell will no
     longer report their status, and will not complain if you try to
     exit an interactive shell with them running or stopped.  If no JOB
     is specified, disown the current job.  With ‘-a’, disown all jobs.

     If the JOBs are currently stopped and the ‘AUTO_CONTINUE’ option is
     not set, a warning is printed containing information about how to
     make them running after they have been disowned.  If one of the
     latter two forms is used, the JOBs will automatically be made
     running, independent of the setting of the ‘AUTO_CONTINUE’ option.

‘echo’ [ ‘-neE’ ] [ ARG … ]

     Write each ARG on the standard output, with a space separating each
     one.  If the ‘-n’ flag is not present, print a newline at the end.
     ‘echo’ recognizes the following escape sequences:

     ‘\a’

          bell character

     ‘\b’

          backspace

     ‘\c’

          suppress subsequent characters and final newline

     ‘\e’

          escape

     ‘\f’

          form feed

     ‘\n’

          linefeed (newline)

     ‘\r’

          carriage return

     ‘\t’

          horizontal tab

     ‘\v’

          vertical tab

     ‘\\’

          backslash

     ‘\0’NNN

          character code in octal

     ‘\x’NN

          character code in hexadecimal

     ‘\u’NNNN

          unicode character code in hexadecimal

     ‘\U’NNNNNNNN

          unicode character code in hexadecimal

     The ‘-E’ flag, or the ‘BSD_ECHO’ option, can be used to disable
     these escape sequences.  In the latter case, ‘-e’ flag can be used
     to enable them.

     Note that for standards compliance a double dash does not terminate
     option processing; instead, it is printed directly.  However, a
     single dash does terminate option processing, so the first dash,
     possibly following options, is not printed, but everything
     following it is printed as an argument.  The single dash behaviour
     is different from other shells.  For a more portable way of
     printing text, see ‘printf’, and for a more controllable way of
     printing text within zsh, see ‘print’.

‘echotc’

     See *note The zsh/termcap Module: bf.

‘echoti’

     See *note The zsh/terminfo Module: c0.

‘emulate’ [ ‘-lLR’ ] [ {‘zsh|sh|ksh|csh’} [ FLAGS … ] ]

     Without any argument print current emulation mode.

     With single argument set up zsh options to emulate the specified
     shell as much as possible.  ‘csh’ will never be fully emulated.  If
     the argument is not one of the shells listed above, ‘zsh’ will be
     used as a default; more precisely, the tests performed on the
     argument are the same as those used to determine the emulation at
     startup based on the shell name, see *note Compatibility: c1.  In
     addition to setting shell options, the command also restores the
     pristine state of pattern enables, as if all patterns had been
     enabled using ‘enable -p’.

     If the ‘emulate’ command occurs inside a function that has been
     marked for execution tracing with ‘functions -t’ then the ‘xtrace’
     option will be turned on regardless of emulation mode or other
     options.  Note that code executed inside the function by the ‘.’,
     ‘source’, or ‘eval’ commands is not considered to be running
     directly from the function, hence does not provoke this behaviour.

     If the ‘-R’ switch is given, all settable options are reset to
     their default value corresponding to the specified emulation mode,
     except for certain options describing the interactive environment;
     otherwise, only those options likely to cause portability problems
     in scripts and functions are altered.  If the ‘-L’ switch is given,
     the options ‘LOCAL_OPTIONS’, ‘LOCAL_PATTERNS’ and ‘LOCAL_TRAPS’
     will be set as well, causing the effects of the ‘emulate’ command
     and any ‘setopt’, ‘disable -p’ or ‘enable -p’, and ‘trap’ commands
     to be local to the immediately surrounding shell function, if any;
     normally these options are turned off in all emulation modes except
     ‘ksh’.  The ‘-L’ switch is mutually exclusive with the use of ‘-c’
     in FLAGS.

     If there is a single argument and the ‘-l’ switch is given, the
     options that would be set or unset (the latter indicated with the
     prefix ‘no’) are listed.  ‘-l’ can be combined with ‘-L’ or ‘-R’
     and the list will be modified in the appropriate way.  Note the
     list does not depend on the current setting of options, i.e.  it
     includes all options that may in principle change, not just those
     that would actually change.

     The FLAGS may be any of the invocation-time flags described in
     *note Invocation: c2, except that ‘-o EMACS’ and ‘-o VI’ may not be
     used.

     If ‘-c’ ARG appears in FLAGS, ARG is evaluated while the requested
     emulation is temporarily in effect.  In this case the emulation
     mode and all options are restored to their previous values before
     ‘emulate’ returns.  The ‘-R’ switch may precede the name of the
     shell to emulate; note this has a meaning distinct from including
     ‘-R’ in FLAGS.

     Use of ‘-c’ enables ‘sticky’ emulation mode for functions defined
     within the evaluated expression: the emulation mode is associated
     thereafter with the function so that whenever the function is
     executed the emulation (respecting the ‘-R’ switch, if present) and
     all options are set (and pattern disables cleared) before entry to
     the function, and the state is restored after exit.  If the
     function is called when the sticky emulation is already in effect,
     either within an ‘emulate’ SHELL ‘-c’ expression or within another
     function with the same sticky emulation, entry and exit from the
     function do not cause options to be altered (except due to standard
     processing such as the ‘LOCAL_OPTIONS’ option).  This also applies
     to functions marked for autoload within the sticky emulation; the
     appropriate set of options will be applied at the point the
     function is loaded as well as when it is run.

     For example:

           emulate sh -c 'fni() { setopt cshnullglob; }
           fno() { fni; }'
           fno

     The two functions ‘fni’ and ‘fno’ are defined with sticky ‘sh’
     emulation.  ‘fno’ is then executed, causing options associated with
     emulations to be set to their values in ‘sh’.  ‘fno’ then calls
     ‘fni’; because ‘fni’ is also marked for sticky ‘sh’ emulation, no
     option changes take place on entry to or exit from it.  Hence the
     option ‘cshnullglob’, turned off by ‘sh’ emulation, will be turned
     on within ‘fni’ and remain on return to ‘fno’.  On exit from ‘fno’,
     the emulation mode and all options will be restored to the state
     they were in before entry to the temporary emulation.

     The documentation above is typically sufficient for the intended
     purpose of executing code designed for other shells in a suitable
     environment.  More detailed rules follow.

       1. The sticky emulation environment provided by ‘emulate’ SHELL
          ‘-c’ is identical to that provided by entry to a function
          marked for sticky emulation as a consequence of being defined
          in such an environment.  Hence, for example, the sticky
          emulation is inherited by subfunctions defined within
          functions with sticky emulation.

       2. No change of options takes place on entry to or exit from
          functions that are not marked for sticky emulation, other than
          those that would normally take place, even if those functions
          are called within sticky emulation.

       3. No special handling is provided for functions marked for
          ‘autoload’ nor for functions present in wordcode created by
          the ‘zcompile’ command.

       4. The presence or absence of the ‘-R’ switch to ‘emulate’
          corresponds to different sticky emulation modes, so for
          example ‘emulate sh -c’, ‘emulate -R sh -c’ and ‘emulate csh
          -c’ are treated as three distinct sticky emulations.

       5. Difference in shell options supplied in addition to the basic
          emulation also mean the sticky emulations are different, so
          for example ‘emulate zsh -c’ and ‘emulate zsh -o cbases -c’
          are treated as distinct sticky emulations.

‘enable’ [ ‘-afmprs’ ] NAME …

     Enable the NAMEd hash table elements, presumably disabled earlier
     with ‘disable’.  The default is to enable builtin commands.  The
     ‘-a’ option causes ‘enable’ to act on regular or global aliases.
     The ‘-s’ option causes ‘enable’ to act on suffix aliases.  The ‘-f’
     option causes ‘enable’ to act on shell functions.  The ‘-r’ option
     causes ‘enable’ to act on reserved words.  Without arguments all
     enabled hash table elements from the corresponding hash table are
     printed.  With the ‘-m’ flag the arguments are taken as patterns
     (should be quoted) and all hash table elements from the
     corresponding hash table matching these patterns are enabled.
     Enabled objects can be disabled with the ‘disable’ builtin command.

     ‘enable -p’ reenables patterns disabled with ‘disable -p’.  Note
     that it does not override globbing options; for example, ‘enable -p
     "~" ``does not cause the pattern character’ ~‘‘ to be active unless
     the ‘EXTENDED_GLOB’ option is also set.  To enable all possible
     patterns (so that they may be individually disabled with ‘disable
     -p’), use ‘setopt EXTENDED_GLOB KSH_GLOB NO_SH_GLOB’.

‘eval’ [ ARG … ]

     Read the arguments as input to the shell and execute the resulting
     command(s) in the current shell process.  The return status is the
     same as if the commands had been executed directly by the shell; if
     there are no ARGS or they contain no commands (i.e.  are an empty
     string or whitespace) the return status is zero.

‘exec’ [ ‘-cl’ ] [ ‘-a’ ARGV0 ] [ COMMAND [ ARG … ] ]

     Replace the current shell with COMMAND rather than forking.  If
     COMMAND is a shell builtin command or a shell function, the shell
     executes it, and exits when the command is complete.

     With ‘-c’ clear the environment; with ‘-l’ prepend ‘-’ to the
     ‘argv[0]’ string of the command executed (to simulate a login
     shell); with ‘-a’ ARGV0 set the ‘argv[0]’ string of the command
     executed.  See *note Precommand Modifiers: b7.

     If the option ‘POSIX_BUILTINS’ is set, COMMAND is never interpreted
     as a shell builtin command or shell function.  This means further
     precommand modifiers such as ‘builtin’ and ‘noglob’ are also not
     interpreted within the shell.  Hence COMMAND is always found by
     searching the command path.

     If COMMAND is omitted but any redirections are specified, then the
     redirections will take effect in the current shell.

‘exit’ [ N ]

     Exit the shell with the exit status specified by an arithmetic
     expression N; if none is specified, use the exit status from the
     last command executed.  ..  index:: single: IGNORE_EOF, use of;
     Program

     An EOF condition will also cause the shell to exit, unless the
     ‘IGNORE_EOF’ option is set.

     See notes at the end of *note Signals: c3. for some possibly
     unexpected interactions of the ‘exit’ command with jobs.

‘export’ [ NAME[‘=’VALUE] … ]

     The specified NAMEs are marked for automatic export to the
     environment of subsequently executed commands.  Equivalent to
     ‘typeset -gx’.  If a parameter specified does not already exist, it
     is created in the global scope.

‘false’ [ ARG … ]

     Do nothing and return an exit status of 1.

‘fc’ [ ‘-e’ ENAME ] [ ‘-s’ ] [ ‘-LI’ ] [ ‘-m’ MATCH ] [ OLD‘=’NEW … ] [
FIRST [ LAST ] ]

‘fc -l’ [ ‘-LI’ ] [ ‘-nrdfEiD’ ] [ ‘-t’ TIMEFMT ] [ ‘-m’ MATCH ]

     [ OLD‘=’NEW … ] [ FIRST [ LAST ] ]

‘fc -p’ [ ‘-a’ ] [ FILENAME [ HISTSIZE [ SAVEHISTSIZE ] ] ]

‘fc’ ‘-P’

‘fc’ ‘-ARWI’ [ FILENAME ]

     The ‘fc’ command controls the interactive history mechanism.  Note
     that reading and writing of history options is only performed if
     the shell is interactive.  Usually this is detected automatically,
     but it can be forced by setting the ‘interactive’ option when
     starting the shell.

     The first two forms of this command select a range of events from
     FIRST to LAST from the history list.  The arguments FIRST and LAST
     may be specified as a number or as a string.  A negative number is
     used as an offset to the current history event number.  A string
     specifies the most recent event beginning with the given string.
     All substitutions OLD‘=’NEW, if any, are then performed on the text
     of the events.

     The range of events selected by numbers can be narrowed further by
     the following flags.

     ‘-I’

          restricts to only internal events (not from ‘$HISTFILE’)

     ‘-L’

          restricts to only local events (not from other shells, see
          ‘SHARE_HISTORY’ in ‘zshoptions’ – note that ‘$HISTFILE’ is
          considered local when read at startup)

     ‘-m’

          takes the first argument as a pattern (which should be quoted)
          and only the history events matching this pattern are
          considered

     If FIRST is not specified, it will be set to -1 (the most recent
     event), or to -16 if the ‘-l’ flag is given.  If LAST is not
     specified, it will be set to FIRST, or to -1 if the ‘-l’ flag is
     given.  However, if the current event has added entries to the
     history with ‘print -s’ or ‘fc -R’, then the default LAST for ‘-l’
     includes all new history entries since the current event began.

     When the ‘-l’ flag is given, the resulting events are listed on
     standard output.  Otherwise the editor program specified by ‘-e’
     ENAME is invoked on a file containing these history events.  If
     ‘-e’ is not given, the value of the parameter ‘FCEDIT’ is used; if
     that is not set the value of the parameter ‘EDITOR’ is used; if
     that is not set a builtin default, usually ‘vi’ is used.  If ENAME
     is ‘-’, no editor is invoked.  When editing is complete, the edited
     command is executed.

     The flag ‘-s’ is equivalent to ‘-e -’.  The flag ‘-r’ reverses the
     order of the events and the flag ‘-n’ suppresses event numbers when
     listing.

     Also when listing,

     ‘-d’

          prints timestamps for each event

     ‘-f’

          prints full time-date stamps in the US MM‘/’DD‘/’YY HH‘:’MM
          format

     ‘-E’

          prints full time-date stamps in the European DD‘.’MM‘.’YYYY
          HH‘:’MM format

     ‘-i’

          prints full time-date stamps in ISO8601 YYYY‘-’MM‘-’DD HH‘:’MM
          format

     ‘-t’ FMT

          prints time and date stamps in the given format; FMT is
          formatted with the strftime function with the zsh extensions
          described for the ‘%D{’STRING‘}’ prompt format in *note Simple
          Prompt Escapes: c4.  The resulting formatted string must be no
          more than 256 characters or will not be printed

     ‘-D’

          prints elapsed times; may be combined with one of the options
          above

     ‘fc -p’ pushes the current history list onto a stack and switches
     to a new history list.  If the ‘-a’ option is also specified, this
     history list will be automatically popped when the current function
     scope is exited, which is a much better solution than creating a
     trap function to call ‘fc -P’ manually.  If no arguments are
     specified, the history list is left empty, ‘$HISTFILE’ is unset,
     and ‘$HISTSIZE’ & ‘$SAVEHIST’ are set to their default values.  If
     one argument is given, ‘$HISTFILE’ is set to that filename,
     ‘$HISTSIZE’ & ‘$SAVEHIST’ are left unchanged, and the history file
     is read in (if it exists) to initialize the new list.  If a second
     argument is specified, ‘$HISTSIZE’ & ‘$SAVEHIST’ are instead set to
     the single specified numeric value.  Finally, if a third argument
     is specified, ‘$SAVEHIST’ is set to a separate value from
     ‘$HISTSIZE’.  You are free to change these environment values for
     the new history list however you desire in order to manipulate the
     new history list.

     ‘fc -P’ pops the history list back to an older list saved by ‘fc
     -p’.  The current list is saved to its ‘$HISTFILE’ before it is
     destroyed (assuming that ‘$HISTFILE’ and ‘$SAVEHIST’ are set
     appropriately, of course).  The values of ‘$HISTFILE’, ‘$HISTSIZE’,
     and ‘$SAVEHIST’ are restored to the values they had when ‘fc -p’
     was called.  Note that this restoration can conflict with making
     these variables “local”, so your best bet is to avoid local
     declarations for these variables in functions that use ‘fc -p’.
     The one other guaranteed-safe combination is declaring these
     variables to be local at the top of your function and using the
     automatic option (‘-a’) with ‘fc -p’.  Finally, note that it is
     legal to manually pop a push marked for automatic popping if you
     need to do so before the function exits.

     ‘fc -R’ reads the history from the given file, ‘fc -W’ writes the
     history out to the given file, and ‘fc -A’ appends the history out
     to the given file.  If no filename is specified, the ‘$HISTFILE’ is
     assumed.  If the ‘-I’ option is added to ‘-R’, only those events
     that are not already contained within the internal history list are
     added.  If the ‘-I’ option is added to ‘-A’ or ‘-W’, only those
     events that are new since last incremental append/write to the
     history file are appended/written.  In any case, the created file
     will have no more than ‘$SAVEHIST’ entries.

‘fg’ [ JOB … ]

JOB …

     Bring each specified JOB in turn to the foreground.  If no JOB is
     specified, resume the current job.

‘float’ [ {‘+|-}Hghlprtux’ ] [ {‘+|-}EFLRZ’ [ N ] ] [ NAME[‘=’VALUE] … ]

     Equivalent to ‘typeset -E’, except that options irrelevant to
     floating point numbers are not permitted.

‘functions’ [ {‘+|-}UkmtTuWz’ ] [ ‘-x’ NUM ] [ NAME … ]

‘functions -c’ OLDFN NEWFN

‘functions -M’ [‘-s’] MATHFN [ MIN [ MAX [ SHELLFN ] ] ]

‘functions -M’ [ ‘-m’ PATTERN … ]

‘functions +M’ [ ‘-m’ ] MATHFN …

     Equivalent to ‘typeset -f’, with the exception of the ‘-c’, ‘-x’,
     ‘-M’ and ‘-W’ options.  For ‘functions -u’ and ‘functions -U’, see
     ‘autoload’, which provides additional options.  For ‘functions -t’
     and ‘functions -T’, see ‘typeset -f’.

     The ‘-x’ option indicates that any functions output will have each
     leading tab for indentation, added by the shell to show syntactic
     structure, expanded to the given number NUM of spaces.  NUM can
     also be 0 to suppress all indentation.

     The ‘-W’ option turns on the option ‘WARN_NESTED_VAR’ for the named
     function or functions only.  The option is turned off at the start
     of nested functions (apart from anonymous functions) unless the
     called function also has the ‘-W’ attribute.

     The ‘-c’ option causes OLDFN to be copied to NEWFN.  The copy is
     efficiently handled internally by reference counting.  If OLDFN was
     marked for autoload it is first loaded and if this fails the copy
     fails.  Either function may subsequently be redefined without
     affecting the other.  A typical idiom is that OLDFN is the name of
     a library shell function which is then redefined to call ‘newfn’,
     thereby installing a modified version of the function.

     ‘The ‘‘’-M‘‘:emphasis:‘ and ‘‘‘+M‘’:emphasis:‘ flags‘ ..  index::
     single: defining mathematical functions; Command

     Use of the ‘-M’ option may not be combined with any of the options
     handled by ‘typeset -f’.

     ‘functions -M’ MATHFN defines MATHFN as the name of a mathematical
     function recognised in all forms of arithmetical expressions; see
     *note Arithmetic Evaluation: c5.  By default MATHFN may take any
     number of comma-separated arguments.  If MIN is given, it must have
     exactly MIN args; if MIN and MAX are both given, it must have at
     least MIN and at most MAX args.  MAX may be -1 to indicate that
     there is no upper limit.

     By default the function is implemented by a shell function of the
     same name; if SHELLFN is specified it gives the name of the
     corresponding shell function while MATHFN remains the name used in
     arithmetical expressions.  The name of the function in ‘$0’ is
     MATHFN (not SHELLFN as would usually be the case), provided the
     option ‘FUNCTION_ARGZERO’ is in effect.  The positional parameters
     in the shell function correspond to the arguments of the
     mathematical function call.

     The result of the last arithmetical expression evaluated inside the
     shell function gives the result of the mathematical function.  This
     is not limited to arithmetic substitutions of the form ‘$((’…‘))’,
     but also includes arithmetical expressions evaluated in any other
     way, including by the ‘let’ builtin, by ‘((’…‘))’ statements, and
     even by the ‘return’ builtin and by array subscripts.  Therefore,
     care must be taken not to use syntactical constructs that perform
     arithmetic evaluation after evaluating what is to be the result of
     the function.  For example:

           # WRONG
           zmath_cube() {
             (( $1 * $1 * $1 ))
             return 0
           }
           functions -M cube 1 1 zmath_cube
           print $(( cube(3) ))

     This will print ‘0’ because of the ‘return’.

     Commenting the ‘return’ out would lead to a different problem: the
     ‘((’…‘))’ statement would become the last statement in the
     function, so the ‘return status’ (‘$?’) of the function would be
     non-zero (indicating failure) whenever the ‘arithmetic result’ of
     the function would happen to be zero (numerically):

           # WRONG
           zmath_cube() {
             (( $1 * $1 * $1 ))
           }
           functions -M cube 1 1 zmath_cube
           print $(( cube(0) ))

     Instead, the ‘true’ builtin can be used:

           # RIGHT
           zmath_cube() {
             (( $1 * $1 * $1 ))
             true
           }
           functions -M cube 1 1 zmath_cube
           print $(( cube(3) ))

     If the additional option ‘-s’ is given to ‘functions -M’, the
     argument to the function is a single string: anything between the
     opening and matching closing parenthesis is passed to the function
     as a single argument, even if it includes commas or white space.
     The minimum and maximum argument specifiers must therefore be 1 if
     given.  An empty argument list is passed as a zero-length string.
     Thus, the following string function takes a single argument,
     including the commas, and prints 11:

           stringfn() { (( $#1 )); true }
           functions -Ms stringfn
           print $(( stringfn(foo,bar,rod) ))

     ‘functions -M’ with no arguments lists all such user-defined
     functions in the same form as a definition.  With the additional
     option ‘-m’ and a list of arguments, all functions whose MATHFN
     matches one of the pattern arguments are listed.

     ‘function +M’ removes the list of mathematical functions; with the
     additional option ‘-m’ the arguments are treated as patterns and
     all functions whose MATHFN matches the pattern are removed.  Note
     that the shell function implementing the behaviour is not removed
     (regardless of whether its name coincides with MATHFN).

‘getcap’

     See *note The zsh/cap Module: bb.

‘getln’ [ ‘-AclneE’ ] NAME …

     Read the top value from the buffer stack and put it in the shell
     parameter NAME.  Equivalent to ‘read -zr’.

‘getopts’ [ ‘-p’ ] OPTSTRING NAME [ ARG … ]

     Checks the ARGs for legal options.  If the ARGs are omitted, the
     positional parameters are used.  A valid option argument begins
     with a ‘+’ or a ‘-’.  An argument not beginning with a ‘+’ or a
     ‘-’, or the argument ‘--’, ends the options.  Note that a single
     ‘-’ is not considered a valid option argument.  OPTSTRING contains
     the letters that ‘getopts’ recognizes.  If a letter is followed by
     a ‘:’, that option requires an argument.  The argument may appear
     either immediately following the option in the same word, or in the
     next word.

     Each time it is invoked, ‘getopts’ places the option letter it
     finds in the shell parameter NAME, prepended with a ‘+’ when ARG
     begins with a ‘+’.  The index of the next ARG is stored in
     ‘OPTIND’.  The option argument, if any, is stored in ‘OPTARG’.  ..
     index:: single: OPTIND, use of; Variable

     When the terminator ‘--’ is encountered, ‘OPTIND’ is incremented
     such that it can be ‘shift’ed away with the options.  This is not
     true of other non-option arguments, including a single ‘-’.

     The first option to be examined may be changed by explicitly
     assigning to ‘OPTIND’.  ‘OPTIND’ has an initial value of ‘1’, and
     is normally set to ‘1’ upon entry to a shell function and restored
     upon exit.  ‘OPTARG’ is not reset and retains its value from the
     most recent call to ‘getopts’.  If either of ‘OPTIND’ or ‘OPTARG’
     is explicitly unset, it remains unset, and the index or option
     argument is not stored.  The option itself is still stored in NAME
     in this case.

     A leading ‘:’ in OPTSTRING causes ‘getopts’ to store the letter of
     any invalid option in ‘OPTARG’, and to set NAME to ‘?’ for an
     unknown option and to ‘:’ when a required argument is missing.
     Otherwise, ‘getopts’ sets NAME to ‘?’ and prints an error message
     when an option is invalid.  The exit status is nonzero when there
     are no more options.

     When either the ‘POSIX_BUILTINS’ option is enabled or the ‘-p’
     option is given to ‘getopts’ itself, ‘getopts’ behaves in a more
     POSIX-compatible manner.  Specifically, handling of ‘+’-prefixed
     options is disabled (they are treated as non-options) and the value
     of ‘OPTIND’ is calculated differently.  Additionally, with
     ‘POSIX_BUILTINS’ (but not with ‘-p’), the value of ‘OPTIND’ is not
     kept local to the calling function.

‘hash’ [ ‘-Ldfmrv’ ] [ NAME[‘=’VALUE] ] …

     ‘hash’ can be used to directly modify the contents of the command
     hash table, and the named directory hash table.  Normally one would
     modify these tables by modifying one’s ‘PATH’ (for the command hash
     table) or by creating appropriate shell parameters (for the named
     directory hash table).  The choice of hash table to work on is
     determined by the ‘-d’ option; without the option the command hash
     table is used, and with the option the named directory hash table
     is used.

     A command NAME starting with a ‘/’ or with a relative path starting
     with ‘./’ or ‘../’ is never executed by lookup in the command hash
     table, and these can only be added to the table by explicit use of
     the ‘hash’ command.  Such a command is always found by direct look
     up in the file system.

     Given no arguments, and neither the ‘-r’ or ‘-f’ options, the
     selected hash table will be listed in full.

     The ‘-r’ option causes the selected hash table to be emptied.  It
     will be subsequently rebuilt in the normal fashion.  The ‘-f’
     option causes the selected hash table to be fully rebuilt
     immediately.  For the command hash table this hashes all (and
     ‘only’) the absolute directories in the ‘PATH’, and for the named
     directory hash table this adds all users’ home directories.  These
     two options cannot be used with any arguments.  Both options remove
     any explicitly-added elements.

     The ‘-m’ option causes the arguments to be taken as patterns (which
     should be quoted) and the elements of the hash table matching those
     patterns are printed.  This is the only way to display a limited
     selection of hash table elements.

     For each NAME with a corresponding VALUE, put NAME in the selected
     hash table, associating it with the pathname VALUE.  In the command
     hash table, this means that whenever NAME is used as a command
     argument, the shell will try to execute the file given by VALUE.
     In the named directory hash table, this means that VALUE may be
     referred to as ‘~’NAME.

     For each NAME with no corresponding VALUE, attempt to add NAME to
     the hash table, checking what the appropriate ‘value’ is in the
     normal manner for that hash table.  If an appropriate ‘value’ can’t
     be found, then the hash table will be unchanged.

     The ‘-v’ option causes hash table entries to be listed as they are
     added by explicit specification.  If has no effect if used with
     ‘-f’.

     If the ‘-L’ flag is present, then each hash table entry is printed
     in the form of a call to hash.

‘history’

     Same as ‘fc -l’.

‘integer’ [ {‘+|-}Hghlprtux’ ] [ {‘+|-}LRZi’ [ N ] ] [ NAME[‘=’VALUE] …
]

     Equivalent to ‘typeset -i’, except that options irrelevant to
     integers are not permitted.

‘jobs’ [ ‘-dlprs’ ] [ JOB … ]

‘jobs -Z’ STRING

     Lists information about each given job, or all jobs if JOB is
     omitted.  The ‘-l’ flag lists process IDs, and the ‘-p’ flag lists
     process groups.  If the ‘-r’ flag is specified only running jobs
     will be listed and if the ‘-s’ flag is given only stopped jobs are
     shown.  If the ‘-d’ flag is given, the directory from which the job
     was started (which may not be the current directory of the job)
     will also be shown.

     The ‘-Z’ option replaces the shell’s argument and environment space
     with the given string, truncated if necessary to fit.  This will
     normally be visible in ‘ps’ (‘ps(1)’) listings.  This feature is
     typically used by daemons, to indicate their state.

     Full job control is only available in the top-level interactive
     shell, not in commands run in the left hand side of pipelines or
     within the ‘(’…‘)’ construct.  However, a snapshot of the job state
     at that point is taken, so it is still possible to use the ‘jobs’
     builtin, or any parameter providing job information.  This gives
     information about the state of jobs at the point the subshell was
     created.  If background processes are created within the subshell,
     then instead information about those processes is provided.

     For example,

           sleep 10 &    # Job in background
           (             # Shell forks
           jobs          # Shows information about "sleep 10 &"
           sleep 5 &     # Process in background (no job control)
           jobs          # Shows information about "sleep 5 &"
           )

‘kill’ [ ‘-s’ SIGNAL_NAME | ‘-n’ SIGNAL_NUMBER | ‘-’SIG ] [ ‘-q’ VALUE ]
JOB …

‘kill’ ‘-l’ [ SIG … ]

‘kill’ ‘-L’

     Sends either ‘SIGTERM’ or the specified signal to the given jobs or
     processes.  Signals are given by number or by names, with or
     without the ‘SIG’ prefix.  If the signal being sent is not ‘KILL’
     or ‘CONT’, then the job will be sent a ‘CONT’ signal if it is
     stopped.  The argument JOB can be the process ID of a job not in
     the job list.  In the second form, ‘kill -l’, if SIG is not
     specified the signal names are listed.  Otherwise, for each SIG
     that is a name, the corresponding signal number is listed.  For
     each SIG that is a signal number or a number representing the exit
     status of a process which was terminated or stopped by a signal the
     name of the signal is printed.  The final form with ‘-L’ lists each
     signal name with its corresponding number.

     On some systems, alternative signal names are allowed for a few
     signals.  Typical examples are ‘SIGCHLD’ and ‘SIGCLD’ or ‘SIGPOLL’
     and ‘SIGIO’, assuming they correspond to the same signal number.
     ‘kill -l ``will only list the preferred form, however’ kill -l‘‘
     ALT will show if the alternative form corresponds to a signal
     number.  For example, under Linux ‘kill -l IO’ and ‘kill -l POLL’
     both output 29, hence ‘kill -IO’ and ‘kill -POLL’ have the same
     effect.

     Many systems will allow process IDs to be negative to kill a
     process group or zero to kill the current process group.

     The ‘-q’ option allows an integer value to be sent with the signal
     on systems that support ‘sigqueue()’.

‘let’ ARG …

     Evaluate each ARG as an arithmetic expression.  See *note
     Arithmetic Evaluation: c5. for a description of arithmetic
     expressions.  The exit status is 0 if the value of the last
     expression is nonzero, 1 if it is zero, and 2 if an error occurred.

‘limit’ [ ‘-hs’ ] [ RESOURCE [ LIMIT ] ] …

     Set or display resource limits.  Unless the ‘-s’ flag is given, the
     limit applies only the children of the shell.  If ‘-s’ is given
     without other arguments, the resource limits of the current shell
     is set to the previously set resource limits of the children.

     If LIMIT is not specified, print the current limit placed on
     RESOURCE, otherwise set the limit to the specified value.  If the
     ‘-h’ flag is given, use hard limits instead of soft limits.  If no
     RESOURCE is given, print all limits.

     When looping over multiple resources, the shell will abort
     immediately if it detects a badly formed argument.  However, if it
     fails to set a limit for some other reason it will continue trying
     to set the remaining limits.

     RESOURCE can be one of:

     ‘addressspace’

          Maximum amount of address space used.

     ‘aiomemorylocked’

          Maximum amount of memory locked in RAM for AIO operations.

     ‘aiooperations’

          Maximum number of AIO operations.

     ‘cachedthreads’

          Maximum number of cached threads.

     ‘coredumpsize’

          Maximum size of a core dump.

     ‘cputime’

          Maximum CPU seconds per process.

     ‘datasize’

          Maximum data size (including stack) for each process.

     ‘descriptors’

          Maximum value for a file descriptor.

     ‘filesize’

          Largest single file allowed.

     ‘kqueues’

          Maximum number of kqueues allocated.

     ‘maxfilelocks’

          Maximum number of file locks.

     ‘maxproc’

          Maximum number of processes.

     ‘maxpthreads’

          Maximum number of threads per process.

     ‘memorylocked’

          Maximum amount of memory locked in RAM.

     ‘memoryuse’

          Maximum resident set size.

     ‘msgqueue’

          Maximum number of bytes in POSIX message queues.

     ‘nice’

          Maximum nice value.

     ‘pipebuf’

          Maximum size of buffers for pipes/fifos.

     ‘posixlocks’

          Maximum number of POSIX locks per user.

     ‘pseudoterminals’

          Maximum number of pseudo-terminals.

     ‘resident’

          Maximum resident set size.

     ‘rt_priority’

          Maximum real-time priority.

     ‘rt_time’

          Maximum CPU time without a blocking system call.

     ‘sigpending’

          Maximum number of pending signals.

     ‘sockbufsize’

          Maximum size of all socket buffers.

     ‘stacksize’

          Maximum stack size for each process.

     ‘swapsize’

          Maximum amount of swap used.

     ‘umtxp’

          Maximum number of POSIX thread library objects.

     ‘vmemorysize’

          Maximum amount of virtual memory.

     ‘vnodemonitors’

          Maximum number of open vnode monitors.

     Which of these resource limits are available depends on the system.
     RESOURCE can be abbreviated to any unambiguous prefix.  It can also
     be an integer, which corresponds to the integer defined for the
     resource by the operating system.

     If argument corresponds to a number which is out of the range of
     the resources configured into the shell, the shell will try to read
     or write the limit anyway, and will report an error if this fails.
     As the shell does not store such resources internally, an attempt
     to set the limit will fail unless the ‘-s’ option is present.

     LIMIT is a number, with an optional scaling factor, as follows:

     N‘h’

          hours

     N‘k’

          kilobytes (default)

     N‘m’

          megabytes or minutes

     N‘g’

          gigabytes

     [MM‘:’]:var:‘ss’

          minutes and seconds

     The ‘limit’ command is not made available by default when the shell
     starts in a mode emulating another shell.  It can be made available
     with the command ‘zmodload -F zsh/rlimits b:limit’.

‘local’ [ {‘+|-}AHUahlprtux’ ] [ {‘+|-}EFLRZi’ [ N ] ] [ NAME[‘=’VALUE]
… ]

     Same as ‘typeset’, except that the options ‘-g’, and ‘-f’ are not
     permitted.  In this case the ‘-x’ option does not force the use of
     ‘-g’, i.e.  exported variables will be local to functions.

‘logout’ [ N ]

     Same as ‘exit’, except that it only works in a login shell.

‘noglob’ SIMPLE COMMAND

     See *note Precommand Modifiers: b7.

‘popd’ [ ‘-q’ ] [ {‘+|-’}:var:‘n’ ]

     Remove an entry from the directory stack, and perform a ‘cd’ to the
     new top directory.  With no argument, the current top entry is
     removed.  An argument of the form ‘+’N identifies a stack entry by
     counting from the left of the list shown by the ‘dirs’ command,
     starting with zero.  An argument of the form ‘-’N counts from the
     right.  ..  index:: single: PUSHD_MINUS, use of; Program

     If the ‘PUSHD_MINUS’ option is set, the meanings of ‘+’ and ‘-’ in
     this context are swapped.

     If the ‘-q’ (quiet) option is specified, the hook function ‘chpwd’
     and the functions in the array ‘$chpwd_functions’ are not called,
     and the new directory stack is not printed.  This is useful for
     calls to ‘popd’ that do not change the environment seen by an
     interactive user.

‘print’ [ ‘-abcDilmnNoOpPrsSz’ ] [ ‘-u’ N ] [ ‘-f’ FORMAT ] [ ‘-C’ COLS
]

          [ ‘-v’ NAME ] [ ‘-xX’ TABSTOP ] [ ‘-R’ [ ‘-en’ ]] [ ARG … ]

     With the ‘-f’ option the arguments are printed as described by
     ‘printf’.  With no flags or with the flag ‘-’, the arguments are
     printed on the standard output as described by ‘echo’, with the
     following differences: the escape sequence ‘\M-’X (or ‘\M’X)
     metafies the character X (sets the highest bit), ‘\C-’X (or ‘\C’X)
     produces a control character (‘\C-@’ and ‘\C-?’ give the characters
     NULL and delete), a character code in octal is represented by
     ‘\’NNN (instead of ‘\0’NNN), and ‘\E’ is a synonym for ‘\e’.
     Finally, if not in an escape sequence, ‘\’ escapes the following
     character and is not printed.

     ‘-a’

          Print arguments with the column incrementing first.  Only
          useful with the ‘-c’ and ‘-C’ options.

     ‘-b’

          Recognize all the escape sequences defined for the ‘bindkey’
          command, see *note Zle Builtins: ba.

     ‘-c’

          Print the arguments in columns.  Unless ‘-a’ is also given,
          arguments are printed with the row incrementing first.

     ‘-C’ COLS

          Print the arguments in COLS columns.  Unless ‘-a’ is also
          given, arguments are printed with the row incrementing first.

     ‘-D’

          Treat the arguments as paths, replacing directory prefixes
          with ‘~’ expressions corresponding to directory names, as
          appropriate.

     ‘-i’

          If given together with ‘-o’ or ‘-O’, sorting is performed
          case-independently.

     ‘-l’

          Print the arguments separated by newlines instead of spaces.
          Note: if the list of arguments is empty, ‘print -l’ will still
          output one empty line.  To print a possibly-empty list of
          arguments one per line, use ‘print -C1’, as in ‘print -rC1 --
          "$list[@]"’.

     ‘-m’

          Take the first argument as a pattern (should be quoted), and
          remove it from the argument list together with subsequent
          arguments that do not match this pattern.

     ‘-n’

          Do not add a newline to the output.

     ‘-N’

          Print the arguments separated and terminated by nulls.  Again,
          ‘print -rNC1 -- "$list[@]"’ is a canonical way to print an
          arbitrary list as null-delimited records.

     ‘-o’

          Print the arguments sorted in ascending order.

     ‘-O’

          Print the arguments sorted in descending order.

     ‘-p’

          Print the arguments to the input of the coprocess.

     ‘-P’

          Perform prompt expansion (see *note Expansion of Prompt
          Sequences: c6.).  In combination with ‘-f’, prompt escape
          sequences are parsed only within interpolated arguments, not
          within the format string.

     ‘-r’

          Ignore the escape conventions of ‘echo’.

     ‘-R’

          Emulate the BSD ‘echo’ command, which does not process escape
          sequences unless the ‘-e’ flag is given.  The ‘-n’ flag
          suppresses the trailing newline.  Only the ‘-e’ and ‘-n’ flags
          are recognized after ‘-R’; all other arguments and options are
          printed.

     ‘-s’

          Place the results in the history list instead of on the
          standard output.  Each argument to the ‘print’ command is
          treated as a single word in the history, regardless of its
          content.

     ‘-S’

          Place the results in the history list instead of on the
          standard output.  In this case only a single argument is
          allowed; it will be split into words as if it were a full
          shell command line.  The effect is similar to reading the line
          from a history file with the ‘HIST_LEX_WORDS’ option active.

     ‘-u’ N

          Print the arguments to file descriptor N.

     ‘-v’ NAME

          Store the printed arguments as the value of the parameter
          NAME.

     ‘-x’ TAB-STOP

          Expand leading tabs on each line of output in the printed
          string assuming a tab stop every TAB-STOP characters.  This is
          appropriate for formatting code that may be indented with
          tabs.  Note that leading tabs of any argument to print, not
          just the first, are expanded, even if ‘print’ is using spaces
          to separate arguments (the column count is maintained across
          arguments but may be incorrect on output owing to previous
          unexpanded tabs).

          The start of the output of each print command is assumed to be
          aligned with a tab stop.  Widths of multibyte characters are
          handled if the option ‘MULTIBYTE’ is in effect.  This option
          is ignored if other formatting options are in effect, namely
          column alignment or ‘printf’ style, or if output is to a
          special location such as shell history or the command line
          editor.

     ‘-X’ TAB-STOP

          This is similar to ‘-x’, except that all tabs in the printed
          string are expanded.  This is appropriate if tabs in the
          arguments are being used to produce a table format.

     ‘-z’

          Push the arguments onto the editing buffer stack, separated by
          spaces.

     If any of ‘-m’, ‘-o’ or ‘-O’ are used in combination with ‘-f’ and
     there are no arguments (after the removal process in the case of
     ‘-m’) then nothing is printed.

‘printf’ [ ‘-v’ NAME ] FORMAT [ ARG … ]

     Print the arguments according to the format specification.
     Formatting rules are the same as used in C. The same escape
     sequences as for ‘echo’ are recognised in the format.  All C
     conversion specifications ending in one of ‘csdiouxXeEfgGn’ are
     handled.  In addition to this, ‘%b’ can be used instead of ‘%s’ to
     cause escape sequences in the argument to be recognised and ‘%q’
     can be used to quote the argument in such a way that allows it to
     be reused as shell input.  With the numeric format specifiers, if
     the corresponding argument starts with a quote character, the
     numeric value of the following character is used as the number to
     print; otherwise the argument is evaluated as an arithmetic
     expression.  See *note Arithmetic Evaluation: c5. for a description
     of arithmetic expressions.  With ‘%n’, the corresponding argument
     is taken as an identifier which is created as an integer parameter.

     Normally, conversion specifications are applied to each argument in
     order but they can explicitly specify the Nth argument is to be
     used by replacing ‘%’ by ‘%’N‘$’ and ‘*’ by ‘*’N‘$’.  It is
     recommended that you do not mix references of this explicit style
     with the normal style and the handling of such mixed styles may be
     subject to future change.

     If arguments remain unused after formatting, the format string is
     reused until all arguments have been consumed.  With the ‘print’
     builtin, this can be suppressed by using the ‘-r’ option.  If more
     arguments are required by the format than have been specified, the
     behaviour is as if zero or an empty string had been specified as
     the argument.

     The ‘-v’ option causes the output to be stored as the value of the
     parameter NAME, instead of printed.  If NAME is an array and the
     format string is reused when consuming arguments then one array
     element will be used for each use of the format string.

‘pushd’ [ ‘-qsLP’ ] [ ARG ]

‘pushd’ [ ‘-qsLP’ ] OLD NEW

‘pushd’ [ ‘-qsLP’ ] {‘+|-’}:var:‘n’

     Change the current directory, and push the old current directory
     onto the directory stack.  In the first form, change the current
     directory to ARG.  If ARG is not specified, change to the second
     directory on the stack (that is, exchange the top two entries), or
     change to ‘$HOME’ if the ‘PUSHD_TO_HOME’ option is set or if there
     is only one entry on the stack.  Otherwise, ARG is interpreted as
     it would be by ‘cd’.  The meaning of OLD and NEW in the second form
     is also the same as for ‘cd’.

     The third form of ‘pushd’ changes directory by rotating the
     directory list.  An argument of the form ‘+’N identifies a stack
     entry by counting from the left of the list shown by the ‘dirs’
     command, starting with zero.  An argument of the form ‘-’N counts
     from the right.  If the ‘PUSHD_MINUS’ option is set, the meanings
     of ‘+’ and ‘-’ in this context are swapped.

     If the ‘-q’ (quiet) option is specified, the hook function ‘chpwd’
     and the functions in the array ‘$chpwd_functions’ are not called,
     and the new directory stack is not printed.  This is useful for
     calls to ‘pushd’ that do not change the environment seen by an
     interactive user.

     If the option ‘-q’ is not specified and the shell option
     ‘PUSHD_SILENT’ is not set, the directory stack will be printed
     after a ‘pushd’ is performed.

     The options ‘-s’, ‘-L’ and ‘-P’ have the same meanings as for the
     ‘cd’ builtin.

‘pushln’ [ ARG … ]

     Equivalent to ‘print -nz’.

‘pwd’ [ ‘-rLP’ ]

     Print the absolute pathname of the current working directory.  If
     the ‘-r’ or the ‘-P’ flag is specified, or the ‘CHASE_LINKS’ option
     is set and the ‘-L’ flag is not given, the printed path will not
     contain symbolic links.

‘r’

     Same as ‘fc -e -’.

‘read’ [ ‘-rszpqAclneE’ ] [ ‘-t’ [ NUM ] ] [ ‘-k’ [ NUM ] ] [ ‘-d’ DELIM
]

          [ ‘-u’ N ] [ [NAME][‘?’PROMPT] ] [ NAME … ]

     Read one line and break it into fields using the characters in
     ‘$IFS’ as separators, except as noted below.  The first field is
     assigned to the first NAME, the second field to the second NAME,
     etc., with leftover fields assigned to the last NAME.  If NAME is
     omitted then ‘REPLY’ is used for scalars and ‘reply’ for arrays.

     ‘-r’

          Raw mode: a ‘\’ at the end of a line does not signify line
          continuation and backslashes in the line don’t quote the
          following character and are not removed.

     ‘-s’

          Don’t echo back characters if reading from the terminal.

     ‘-q’

          Read only one character from the terminal and set NAME to ‘y’
          if this character was ‘y’ or ‘Y’ and to ‘n’ otherwise.  With
          this flag set the return status is zero only if the character
          was ‘y’ or ‘Y’.  This option may be used with a timeout (see
          ‘-t’); if the read times out, or encounters end of file,
          status 2 is returned.  Input is read from the terminal unless
          one of ‘-u’ or ‘-p’ is present.  This option may also be used
          within zle widgets.

     ‘-k’ [ NUM ]

          Read only one (or NUM) characters.  All are assigned to the
          first NAME, without word splitting.  This flag is ignored when
          ‘-q’ is present.  Input is read from the terminal unless one
          of ‘-u’ or ‘-p’ is present.  This option may also be used
          within zle widgets.

          Note that despite the mnemonic ‘key’ this option does read
          full characters, which may consist of multiple bytes if the
          option ‘MULTIBYTE’ is set.

     ‘-z’

          Read one entry from the editor buffer stack and assign it to
          the first NAME, without word splitting.  Text is pushed onto
          the stack with ‘print -z’ or with ‘push-line’ from the line
          editor (see ‘zshzle’).  This flag is ignored when the ‘-k’ or
          ‘-q’ flags are present.

     ‘-e’

     ‘-E’

          The input read is printed (echoed) to the standard output.  If
          the ‘-e’ flag is used, no input is assigned to the parameters.

     ‘-A’

          The first NAME is taken as the name of an array and all words
          are assigned to it.

     ‘-c’

     ‘-l’

          These flags are allowed only if called inside a function used
          for completion (specified with the ‘-K’ flag to ‘compctl’).
          If the ‘-c’ flag is given, the words of the current command
          are read.  If the ‘-l’ flag is given, the whole line is
          assigned as a scalar.  If both flags are present, ‘-l’ is used
          and ‘-c’ is ignored.

     ‘-n’

          Together with ‘-c’, the number of the word the cursor is on is
          read.  With ‘-l’, the index of the character the cursor is on
          is read.  Note that the command name is word number 1, not
          word 0, and that when the cursor is at the end of the line,
          its character index is the length of the line plus one.

     ‘-u’ N

          Input is read from file descriptor N.

     ‘-p’

          Input is read from the coprocess.

     ‘-d’ DELIM

          Input is terminated by the first character of DELIM instead of
          by newline.  For compatibility with other shells, if DELIM is
          an empty string, input is terminated at the first NUL.

     ‘-t’ [ NUM ]

          Test if input is available before attempting to read.  If NUM
          is present, it must begin with a digit and will be evaluated
          to give a number of seconds, which may be a floating point
          number; in this case the read times out if input is not
          available within this time.  If NUM is not present, it is
          taken to be zero, so that ‘read’ returns immediately if no
          input is available.  If no input is available, return status 1
          and do not set any variables.

          This option is not available when reading from the editor
          buffer with ‘-z’, when called from within completion with ‘-c’
          or ‘-l’, with ‘-q’ which clears the input queue before
          reading, or within zle where other mechanisms should be used
          to test for input.

          Note that read does not attempt to alter the input processing
          mode.  The default mode is canonical input, in which an entire
          line is read at a time, so usually ‘read -t’ will not read
          anything until an entire line has been typed.  However, when
          reading from the terminal with ‘-k’ input is processed one key
          at a time; in this case, only availability of the first
          character is tested, so that e.g.  ‘read -t -k 2’ can still
          block on the second character.  Use two instances of ‘read -t
          -k’ if this is not what is wanted.

     If the first argument contains a ‘?’, the remainder of this word is
     used as a PROMPT on standard error when the shell is interactive.

     The value (exit status) of ‘read’ is 1 when an end-of-file is
     encountered, or when ‘-c’ or ‘-l’ is present and the command is not
     called from a ‘compctl’ function, or as described for ‘-q’.
     Otherwise the value is 0.

     The behavior of some combinations of the ‘-k’, ‘-p’, ‘-q’, ‘-u’ and
     ‘-z’ flags is undefined.  Presently ‘-q’ cancels all the others,
     ‘-p’ cancels ‘-u’, ‘-k’ cancels ‘-z’, and otherwise ‘-z’ cancels
     both ‘-p’ and ‘-u’.

     The ‘-c’ or ‘-l’ flags cancel any and all of ‘-kpquz’.

‘readonly’

     Same as ‘typeset -r’.  With the ‘POSIX_BUILTINS’ option set, same
     as ‘typeset -gr’.

‘rehash’

     Same as ‘hash -r’.

‘return’ [ N ]

     Causes a shell function or ‘.’ script to return to the invoking
     script with the return status specified by an arithmetic expression
     N.  Also causes a non-interactive shell to exit, allowing files
     containing shell code to be used both as scripts and as
     autoloadable shell functions.  For example, the following prints
     ‘42’:

           () { integer foo=40; return "foo + 2" }
           echo $?

     If N is omitted, the return status is that of the last command
     executed.

     If ‘return’ was executed from a trap in a ‘TRAP’NAL function, the
     effect is different for zero and non-zero return status.  With zero
     status (or after an implicit return at the end of the trap), the
     shell will return to whatever it was previously processing; with a
     non-zero status, the shell will behave as interrupted except that
     the return status of the trap is retained.  Note that the numeric
     value of the signal which caused the trap is passed as the first
     argument, so the statement ‘return "128+$1"’ will return the same
     status as if the signal had not been trapped.

‘sched’

     See *note The zsh/sched Module: 96.

‘set’ [ {‘+|-’}:var:‘options’ | {‘+|-}o’ [ OPTION_NAME ] ] … [ {‘+|-}A’
[ NAME ] ]

     [ ARG … ]

     Set the options for the shell and/or set the positional parameters,
     or declare and set an array.  If the ‘-s’ option is given, it
     causes the specified arguments to be sorted before assigning them
     to the positional parameters (or to the array NAME if ‘-A’ is
     used).  With ‘+s’ sort arguments in descending order.  For the
     meaning of the other flags, see ‘zshoptions’.  Flags may be
     specified by name using the ‘-o’ option.  If no option name is
     supplied with ‘-o’, the current option states are printed: see the
     description of ‘setopt’ below for more information on the format.
     With ‘+o’ they are printed in a form that can be used as input to
     the shell.

     If the ‘-A’ flag is specified, NAME is set to an array containing
     the given ARGs; if no NAME is specified, all arrays are printed
     together with their values.

     If ‘+A’ is used and NAME is an array, the given arguments will
     replace the initial elements of that array; if no NAME is
     specified, all arrays are printed without their values.

     The behaviour of arguments after ‘-A’ NAME or ‘+A’ NAME depends on
     whether the option ‘KSH_ARRAYS’ is set.  If it is not set, all
     arguments following NAME are treated as values for the array,
     regardless of their form.  If the option is set, normal option
     processing continues at that point; only regular arguments are
     treated as values for the array.  This means that

           set -A array -x -- foo

     sets ‘array’ to ‘-x -- foo’ if ‘KSH_ARRAYS’ is not set, but sets
     the array to ‘foo’ and turns on the option ‘-x’ if it is set.

     If the ‘-A’ flag is not present, but there are arguments beyond the
     options, the positional parameters are set.  If the option list (if
     any) is terminated by ‘--’, and there are no further arguments, the
     positional parameters will be unset.

     If no arguments and no ‘--’ are given, then the names and values of
     all parameters are printed on the standard output.  If the only
     argument is ‘+’, the names of all parameters are printed.

     For historical reasons, ‘set -’ is treated as ‘set +xv’ and ‘set -’
     ARGS as ‘set +xv --’ ARGS when in any other emulation mode than
     zsh’s native mode.

‘setcap’

     See *note The zsh/cap Module: bb.

‘setopt’ [ {‘+|-’}:var:‘options’ | {‘+|-}o’ OPTION_NAME ] [ ‘-m’ ] [
NAME … ]

     Set the options for the shell.  All options specified either with
     flags or by name are set.

     If no arguments are supplied, the names of all options currently
     set are printed.  The form is chosen so as to minimize the
     differences from the default options for the current emulation (the
     default emulation being native ‘zsh’, shown as ‘<Z>’ in *note
     Description of Options: 9c.).  Options that are on by default for
     the emulation are shown with the prefix ‘no’ only if they are off,
     while other options are shown without the prefix ‘no’ and only if
     they are on.  In addition to options changed from the default state
     by the user, any options activated automatically by the shell (for
     example, ‘SHIN_STDIN’ or ‘INTERACTIVE’) will be shown in the list.
     The format is further modified by the option ‘KSH_OPTION_PRINT’,
     however the rationale for choosing options with or without the ‘no’
     prefix remains the same in this case.

     If the ‘-m’ flag is given the arguments are taken as patterns
     (which should be quoted to protect them from filename expansion),
     and all options with names matching these patterns are set.

     Note that a bad option name does not cause execution of subsequent
     shell code to be aborted; this behaviour is different from that of
     ‘set -o’.  This is because‘‘ set‘‘ is regarded as a special builtin
     by the POSIX standard, but ‘setopt’ is not.

‘shift’ [ ‘-p’ ] [ N ] [ NAME … ]

     The positional parameters ‘${’N+1‘‘}‘‘ … are renamed to ‘$1’ …,
     where N is an arithmetic expression that defaults to 1.  If any
     NAMEs are given then the arrays with these names are shifted
     instead of the positional parameters.

     If the option ‘-p’ is given arguments are instead removed (popped)
     from the end rather than the start of the array.

‘source’ FILE [ ARG … ]

     Same as ‘.’, except that the current directory is always searched
     and is always searched first, before directories in ‘$path’.

‘stat’

     See *note The zsh/stat Module: c7.

‘suspend’ [ ‘-f’ ]

     Suspend the execution of the shell (send it a ‘SIGTSTP’) until it
     receives a ‘SIGCONT’.  Unless the ‘-f’ option is given, this will
     refuse to suspend a login shell.

‘test’ [ ARG … ]

‘[’ [ ARG … ] ‘]’

     Like the system version of ‘test’.  Added for compatibility; use
     conditional expressions instead (see *note Conditional Expressions:
     c8.).  The main differences between the conditional expression
     syntax and the ‘test’ and ‘[’ builtins are: these commands are not
     handled syntactically, so for example an empty variable expansion
     may cause an argument to be omitted; syntax errors cause status 2
     to be returned instead of a shell error; and arithmetic operators
     expect integer arguments rather than arithmetic expressions.

     The command attempts to implement POSIX and its extensions where
     these are specified.  Unfortunately there are intrinsic ambiguities
     in the syntax; in particular there is no distinction between test
     operators and strings that resemble them.  The standard attempts to
     resolve these for small numbers of arguments (up to four); for five
     or more arguments compatibility cannot be relied on.  Users are
     urged wherever possible to use the ‘[[’ test syntax which does not
     have these ambiguities.

‘times’

     Print the accumulated user and system times for the shell and for
     processes run from the shell.

‘trap’ [ ARG ] [ SIG … ]

     ARG is a series of commands (usually quoted to protect it from
     immediate evaluation by the shell) to be read and executed when the
     shell receives any of the signals specified by one or more SIG
     args.  Each SIG can be given as a number, or as the name of a
     signal either with or without the string ‘SIG’ in front (e.g.  1,
     HUP, and SIGHUP are all the same signal).

     If ARG is ‘-’, then the specified signals are reset to their
     defaults, or, if no SIG args are present, all traps are reset.

     If ARG is an empty string, then the specified signals are ignored
     by the shell (and by the commands it invokes).

     If ARG is omitted but one or more SIG args are provided (i.e.  the
     first argument is a valid signal number or name), the effect is the
     same as if ARG had been specified as ‘-’.

     The ‘trap’ command with no arguments prints a list of commands
     associated with each signal.

     If SIG is ‘ZERR’ then ARG will be executed after each command with
     a nonzero exit status.  ‘ERR’ is an alias for ‘ZERR’ on systems
     that have no ‘SIGERR’ signal (this is the usual case).

     If SIG is ‘DEBUG’ then ARG will be executed before each command if
     the option ‘DEBUG_BEFORE_CMD’ is set (as it is by default), else
     after each command.  Here, a ‘command’ is what is described as a
     ‘sublist’ in the shell grammar, see *note Simple Commands &
     Pipelines: c9.  If ‘DEBUG_BEFORE_CMD’ is set various additional
     features are available.  First, it is possible to skip the next
     command by setting the option ‘ERR_EXIT’; see the description of
     the ‘ERR_EXIT’ option in ‘zshoptions’.  Also, the shell parameter
     ‘ZSH_DEBUG_CMD’ is set to the string corresponding to the command
     to be executed following the trap.  Note that this string is
     reconstructed from the internal format and may not be formatted the
     same way as the original text.  The parameter is unset after the
     trap is executed.

     If SIG is ‘0’ or ‘EXIT’ and the ‘trap’ statement is executed inside
     the body of a function, then the command ARG is executed after the
     function completes.  The value of ‘$?’ at the start of execution is
     the exit status of the shell or the return status of the function
     exiting.  If SIG is ‘0’ or ‘EXIT’ and the ‘trap’ statement is not
     executed inside the body of a function, then the command ARG is
     executed when the shell terminates; the trap runs before any
     ‘zshexit’ hook functions.

     ‘ZERR’, ‘DEBUG’, and ‘EXIT’ traps are not executed inside other
     traps.  ‘ZERR’ and ‘DEBUG’ traps are kept within subshells, while
     other traps are reset.

     Note that traps defined with the ‘trap’ builtin are slightly
     different from those defined as ‘TRAP’NAL () { … }, as the latter
     have their own function environment (line numbers, local variables,
     etc.)  while the former use the environment of the command in which
     they were called.  For example,

           trap 'print $LINENO' DEBUG

     will print the line number of a command executed after it has run,
     while

           TRAPDEBUG() { print $LINENO; }

     will always print the number zero.

     Alternative signal names are allowed as described under ‘kill’
     above.  Defining a trap under either name causes any trap under an
     alternative name to be removed.  However, it is recommended that
     for consistency users stick exclusively to one name or another.

‘true’ [ ARG … ]

     Do nothing and return an exit status of 0.

‘ttyctl’ [ ‘-fu’ ]

     The ‘-f’ option freezes the tty (i.e.  terminal or terminal
     emulator), and ‘-u’ unfreezes it.  When the tty is frozen, no
     changes made to the tty settings by external programs will be
     honored by the shell, except for changes in the size of the screen;
     the shell will simply reset the settings to their previous values
     as soon as each command exits or is suspended.  Thus, ‘stty’ and
     similar programs have no effect when the tty is frozen.  Freezing
     the tty does not cause the current state to be remembered: instead,
     it causes future changes to the state to be blocked.

     Without options it reports whether the terminal is frozen or not.

     Note that, regardless of whether the tty is frozen or not, the
     shell needs to change the settings when the line editor starts, so
     unfreezing the tty does not guarantee settings made on the command
     line are preserved.  Strings of commands run between editing the
     command line will see a consistent tty state.  See also the shell
     variable ‘STTY’ for a means of initialising the tty before running
     external commands and/or freezing the tty around a single command.

‘type’ [ ‘-wfpamsS’ ] NAME …

     Equivalent to ‘whence -v’.

‘typeset’ [ {‘+|-}AHUaghlmrtux’ ] [ {‘+|-}EFLRZip’ [ N ] ]

     [ ‘+’ ] [ NAME[‘=’VALUE] … ]

‘typeset {+|-}n’ [ ‘-g’ ] [ {‘+|-}r’ ] [ NAME[‘=’VALUE] … ]

‘typeset -T’ [ {‘+|-}Uglrux’ ] [ {‘+|-}LRZp’ [ N ] ]

     [ ‘+’ | SCALAR[‘=’VALUE] ARRAY[‘=(’VALUE …‘‘)‘‘] [ SEP ] ]

‘typeset’ ‘-f’ [ {‘+|-}TUkmtuz’ ] [ ‘+’ ] [ NAME … ]

     Set or display attributes and values for shell parameters.

     Except as noted below for control flags that change the behavior, a
     parameter is created for each NAME that does not already refer to
     one.  When inside a function, a new parameter is created for every
     NAME (even those that already exist), and is unset again when the
     function completes.  See *note Local Parameters: 40.  The same
     rules apply to special shell parameters, which retain their special
     attributes when made local.

     For each NAME‘=’VALUE assignment, the parameter NAME is set to
     VALUE.  If the assignment is omitted and NAME does ‘not’ refer to
     an existing parameter, a new parameter is initialized to empty
     string, zero, or empty array (as appropriate), ‘unless’ the shell
     option ‘TYPESET_TO_UNSET’ is set.  When that option is set, the
     parameter attributes are recorded but the parameter remains unset.

     If the shell option ‘TYPESET_SILENT’ is not set, for each remaining
     NAME that refers to a parameter that is already set, the name and
     value of the parameter are printed in the form of an assignment.
     Nothing is printed for newly-created parameters, or when any
     attribute flags listed below are given along with the NAME.  Using
     ‘+’ instead of minus to introduce an attribute turns it off.

     If no NAME is present, the names and values of all parameters are
     printed.  In this case the attribute flags restrict the display to
     only those parameters that have the specified attributes, and using
     ‘+’ rather than ‘-’ to introduce the flag suppresses printing of
     the values of parameters when there is no parameter name.

     All forms of the command handle scalar assignment.  Array
     assignment is possible if any of the reserved words ‘declare’,
     ‘export’, ‘float’, ‘integer’, ‘local’, ‘readonly’ or ‘typeset’ is
     matched when the line is parsed (N.B. not when it is executed).  In
     this case the arguments are parsed as assignments, except that the
     ‘+=’ syntax and the ‘GLOB_ASSIGN’ option are not supported, and
     scalar values after ‘=’ are ‘not’ split further into words, even if
     expanded (regardless of the setting of the ‘KSH_TYPESET’ option;
     this option is obsolete).

     Examples of the differences between command and reserved word
     parsing:

           # Reserved word parsing
           typeset svar=$(echo one word) avar=(several words)

     The above creates a scalar parameter ‘svar’ and an array parameter
     ‘avar’ as if the assignments had been

           svar="one word"
           avar=(several words)

     On the other hand:

           # Normal builtin interface
           builtin typeset svar=$(echo two words)

     The ‘builtin’ keyword causes the above to use the standard builtin
     interface to ‘typeset’ in which argument parsing is performed in
     the same way as for other commands.  This example creates a scalar
     ‘svar’ containing the value ‘two’ and another scalar parameter
     ‘words’ with no value.  An array value in this case would either
     cause an error or be treated as an obscure set of glob qualifiers.

     Arbitrary arguments are allowed if they take the form of
     assignments after command line expansion; however, these only
     perform scalar assignment:

           var='svar=val'
           typeset $var

     The above sets the scalar parameter ‘svar’ to the value ‘val’.
     Parentheses around the value within ‘var’ would not cause array
     assignment as they will be treated as ordinary characters when
     ‘$var’ is substituted.  Any non-trivial expansion in the name part
     of the assignment causes the argument to be treated in this
     fashion:

           typeset {var1,var2,var3}=name

     The above syntax is valid, and has the expected effect of setting
     the three parameters to the same value, but the command line is
     parsed as a set of three normal command line arguments to ‘typeset’
     after expansion.  Hence it is not possible to assign to multiple
     arrays by this means.

     Note that each interface to any of the commands may be disabled
     separately.  For example, ‘disable -r typeset’ disables the
     reserved word interface to ‘typeset’, exposing the builtin
     interface, while ‘disable typeset’ disables the builtin.  Note that
     disabling the reserved word interface for ‘typeset’ may cause
     problems with the output of ‘typeset -p’, which assumes the
     reserved word interface is available in order to restore array and
     associative array values.

     Unlike parameter assignment statements, ‘typeset’’s exit status on
     an assignment that involves a command substitution does not reflect
     the exit status of the command substitution.  Therefore, to test
     for an error in a command substitution, separate the declaration of
     the parameter from its initialization:

           # WRONG
           typeset var1=$(exit 1) || echo "Trouble with var1"

           # RIGHT
           typeset var1 && var1=$(exit 1) || echo "Trouble with var1"

     To initialize a parameter PARAM to a command output and mark it
     readonly, use ‘typeset -r’ PARAM or ‘readonly’ PARAM after the
     parameter assignment statement.

     The flag ‘-n’ creates a ‘named reference’ to another parameter.
     The second parameter need not exist at the time the reference is
     created.  Only the ‘-H’, ‘-g’, and ‘-r’ flags may be used in
     conjunction with ‘-n’, having their usual meanings.  The ‘-u’ flag
     is special and may be applied to alter the scope of the reference.
     The NAME so created may not be an array element nor use a
     subscript, but the VALUE assigned may be any valid parameter name
     syntax, even a subscripted array element (including an associative
     array element) or an array slice, which is evaluated when the named
     reference is expanded.  It is an error for a named reference to
     refer to itself, even indirectly through a chain of references.
     When ‘-u’ is applied to a named reference, the parameter identified
     by VALUE is always found in the calling function scope rather than
     the current local scope.  In this case, if there is no such
     parameter in the calling scope, assignments to the named reference
     may fail, setting ‘$?’ to 1.  See *note Parameter Expansion: 1a.
     and *note Named References: 71. for details of the behavior of
     named references.

     Local function scoping rules for ‘typeset’ do apply with ‘-n’, so a
     declaration within a function persists only until the end of the
     function unless ‘-g -n’ is specified, and any local parameter (of
     any type) with the same NAME supplants a named reference from a
     surrounding scope.

     A scalar parameter, including an existing named reference, may be
     converted to a new named reference by ‘typeset -n’ NAME, so the
     ‘-p’ option must be included to display the value of a specific
     named reference NAME.

     If no attribute flags are given, and either no NAME arguments are
     present or the flag ‘+m’ is used, then each parameter name printed
     is preceded by a list of the attributes of that parameter (‘array’,
     ‘association’, ‘exported’, ‘float’, ‘integer’, ‘readonly’, or
     ‘undefined’ for autoloaded parameters not yet loaded).  If ‘+m’ is
     used with attribute flags, and all those flags are introduced with
     ‘+’, the matching parameter names are printed but their values are
     not.

     The following control flags change the behavior of ‘typeset’:

     ‘+’

          If ‘+’ appears by itself in a separate word as the last
          option, then the names of all parameters (functions with ‘-f’)
          are printed, but the values (function bodies) are not.  If
          NAME arguments appear, both those names and their values are
          printed in the form of assignments.  It is an error for any
          other options to follow ‘+’, but the effect of ‘+’ is as if
          all attribute flags which precede it were given with a ‘+’
          prefix.  For example, ‘typeset -U +’ is equivalent to ‘typeset
          +U’ and displays the names of all arrays having the uniqueness
          attribute, whereas ‘typeset -f -U +’ displays the names of all
          autoloadable functions.  If ‘+’ is the only option, then type
          information (array, readonly, etc.)  is also printed for each
          parameter, in the same manner as ‘typeset +m "*"’.

     ‘-g’

          The ‘-g’ (global) means that any resulting parameter will not
          be restricted to local scope.  Note that this does not
          necessarily mean that the parameter will be global, as the
          flag will apply to any existing parameter (even if unset) from
          an enclosing function.  This flag does not affect the
          parameter after creation, hence it has no effect when listing
          existing parameters, nor does the flag ‘+g’ have any effect
          except in combination with ‘-m’ (see below).

     ‘-m’

          If the ‘-m’ flag is given the NAME arguments are taken as
          patterns (use quoting to prevent these from being interpreted
          as file patterns).  With no attribute flags, all parameters
          (or functions with the ‘-f’ flag) with matching names are
          printed (the shell option ‘TYPESET_SILENT’ is not used in this
          case).

          If the ‘+g’ flag is combined with ‘-m’, a new local parameter
          is created for every matching parameter that is not already
          local.  Otherwise ‘-m’ applies all other flags or assignments
          to the existing parameters, except that the ‘-n’ option cannot
          create named references in this way.

          Except when assignments are made with NAME‘=’VALUE, using ‘+m’
          forces the matching parameters and their attributes to be
          printed, even inside a function.  Note that ‘-m’ is ignored if
          no patterns are given, so ‘typeset -m’ displays attributes but
          ‘typeset -a +m’ does not.  Ordinary scalar string parameters
          have no attributes, so for those ‘+m’ prints only the names.

     ‘-p’ [ N ]

          If the ‘-p’ option is given, parameters and values are printed
          in the form of a typeset command with an assignment,
          regardless of other flags and options.  Note that the ‘-H’
          flag on parameters is respected; no value will be shown for
          these parameters.

          ‘-p’ may be followed by an optional integer argument.
          Currently only the value ‘1’ is supported.  In this case
          arrays and associative arrays are printed with newlines
          between indented elements for readability.

          The names and values of readonly special parameters (most of
          the parameters marked ‘<S>’ in *note Parameters Set by the
          Shell: 93, except those documented as settable) are not
          printed with ‘-p’ because to execute those typeset commands
          would cause errors.  However, these parameters are printed
          when they have been made local to the scope where ‘typeset -p’
          is run.

     ‘-T’ [ SCALAR[‘=’VALUE] ARRAY[‘=(’VALUE …‘‘)‘‘] [ SEP ] ]

          This flag has a different meaning when used with ‘-f’; see
          below.  Otherwise the ‘-T’ option requires zero, two, or three
          arguments to be present.  With no arguments, the list of
          parameters created in this fashion is shown.  With two or
          three arguments, the first two are the name of a scalar and of
          an array parameter (in that order) that will be tied together
          in the manner of ‘$PATH’ and ‘$path’.  The optional third
          argument is a single-character separator which will be used to
          join the elements of the array to form the scalar; if absent,
          a colon is used, as with ‘$PATH’.  Only the first character of
          the separator is significant; any remaining characters are
          ignored.  Multibyte characters are not yet supported.

          Only one of the scalar and array parameters may be assigned an
          initial value (the restrictions on assignment forms described
          above also apply).

          Both the scalar and the array may be manipulated as normal.
          If one is unset, the other will automatically be unset too.
          There is no way of untying the variables without unsetting
          them, nor of converting the type of one of them with another
          ‘typeset’ command; ‘+T’ does not work, assigning an array to
          SCALAR is an error, and assigning a scalar to ARRAY sets it to
          be a single-element array.

          Note that both ‘typeset -xT ...’ and ‘export -T ...’ work, but
          only the scalar will be marked for export.  Setting the value
          using the scalar version causes a split on all separators
          (which cannot be quoted).  It is possible to apply ‘-T’ to two
          previously tied variables but with a different separator
          character, in which case the variables remain joined as before
          but the separator is changed.

          When an existing scalar is tied to a new array, the value of
          the scalar is preserved but no attribute other than export
          will be preserved.

     Attribute flags that transform the final value (‘-L’, ‘-R’, ‘-Z’,
     ‘-l’, ‘-u’) are only applied to the expanded value at the point of
     a parameter expansion expression using ‘$’.  They are not applied
     when a parameter is retrieved internally by the shell for any
     purpose.

     The following attribute flags may be specified:

     ‘-A’

          The names refer to associative array parameters; see *note
          Array Parameters: 1b.

     ‘-L’ [ N ]

          Left justify and remove leading blanks from the value when the
          parameter is expanded.  If N is nonzero, it defines the width
          of the field.  If N is zero, the width is determined by the
          width of the value of the first assignment.  In the case of
          numeric parameters, the length of the complete value assigned
          to the parameter is used to determine the width, not the value
          that would be output.

          The width is the count of characters, which may be multibyte
          characters if the ‘MULTIBYTE’ option is in effect.  Note that
          the screen width of the character is not taken into account;
          if this is required, use padding with parameter expansion
          flags ‘${(ml’…‘)’…‘}’ as described in *note Parameter
          Expansion Flags: 6e.

          When the parameter is expanded, it is filled on the right with
          blanks or truncated if necessary to fit the field.  Note
          truncation can lead to unexpected results with numeric
          parameters.  Leading zeros are removed if the ‘-Z’ flag is
          also set.

     ‘-R’ [ N ]

          Similar to ‘-L’, except that right justification is used; when
          the parameter is expanded, the field is left filled with
          blanks or truncated from the end.  May not be combined with
          the ‘-Z’ flag.

     ‘-U’

          For arrays (but not for associative arrays), keep only the
          first occurrence of each duplicated value.  This may also be
          set for tied parameters (see ‘-T’) or colon-separated special
          parameters like ‘PATH’ or ‘FIGNORE’, etc.  Note the flag takes
          effect on assignment, and the type of the variable being
          assigned to is determinative; for variables with shared values
          it is therefore recommended to set the flag for all
          interfaces, e.g.  ‘typeset -U PATH path’.

          This flag has a different meaning when used with ‘-f’; see
          below.

     ‘-Z’ [ N ]

          Specially handled if set along with the ‘-L’ flag.  Otherwise,
          similar to ‘-R’, except that leading zeros are used for
          padding instead of blanks if the first non-blank character is
          a digit.  Numeric parameters are specially handled: they are
          always eligible for padding with zeroes, and the zeroes are
          inserted at an appropriate place in the output.

     ‘-a’

          The names refer to array parameters.  An array parameter may
          be created this way, but it may be assigned to in the
          ‘typeset’ statement only if the reserved word form of
          ‘typeset’ is enabled (as it is by default).  When displaying,
          both normal and associative arrays are shown.

     ‘-f’

          The names refer to functions rather than parameters.  No
          assignments can be made, and the only other valid flags are
          ‘-t’, ‘-T’, ‘-k’, ‘-u’, ‘-U’ and ‘-z’.  The flag ‘-t’ turns on
          execution tracing for this function; the flag ‘-T’ does the
          same, but turns off tracing for any named (not anonymous)
          function called from the present one, unless that function
          also has the ‘-t’ or ‘-T’ flag.  The ‘-u’ and ‘-U’ flags cause
          the function to be marked for autoloading; ‘-U’ also causes
          alias expansion to be suppressed when the function is loaded.
          See the description of the ‘autoload’ builtin for details.

          Note that the builtin ‘functions’ provides the same basic
          capabilities as ‘typeset -f’ but gives access to a few extra
          options; ‘autoload’ gives further additional options for the
          case ‘typeset -fu’ and ‘typeset -fU’.

     ‘-h’

          Hide: only useful for special parameters (those marked ‘<S>’
          in the table in *note Parameters Set by the Shell: 93.), and
          for local parameters with the same name as a special
          parameter, though harmless for others.  A special parameter
          with this attribute will not retain its special effect when
          made local.  Thus after ‘typeset -h PATH’, a function
          containing‘‘ typeset PATH‘‘ will create an ordinary local
          parameter without the usual behaviour of ‘PATH’.
          Alternatively, the local parameter may itself be given this
          attribute; hence inside a function ‘typeset -h PATH’ creates
          an ordinary local parameter and the special ‘PATH’ parameter
          is not altered in any way.  It is also possible to create a
          local parameter using ‘typeset +h’ SPECIAL, where the local
          copy of SPECIAL will retain its special properties regardless
          of having the ‘-h’ attribute.  Global special parameters
          loaded from shell modules (for example, those in ‘zsh/mapfile’
          and ‘zsh/parameter’) are automatically given the ‘-h’
          attribute to avoid name clashes.

     ‘-H’

          Hide value: specifies that ‘typeset’ will not display the
          value of the parameter when listing parameters; the display
          for such parameters is always as if the ‘+’ flag were given,
          but use of the parameter is in other respects normal.  This
          effect does not apply when the parameter is specified by name
          or by pattern with the ‘-m’ option.  This is on by default for
          the parameters in the ‘zsh/parameter’ and ‘zsh/mapfile’
          modules.  Note, however, that unlike the ‘-h’ flag this is
          also useful for non-special parameters.

     ‘-i’ [ N ]

          Use an internal integer representation.  If N is nonzero it
          defines the output arithmetic base, otherwise it is determined
          by the first assignment.  Bases from 2 to 36 inclusive are
          allowed.

     ‘-E’ [ N ]

          Use an internal double-precision floating point
          representation.  On output the variable will be converted to
          scientific notation.  If N is nonzero it defines the number of
          significant figures to display; the default is ten.

     ‘-F’ [ N ]

          Use an internal double-precision floating point
          representation.  On output the variable will be converted to
          fixed-point decimal notation.  If N is nonzero it defines the
          number of digits to display after the decimal point; the
          default is ten.

     ‘-l’

          Convert the result to lower case whenever the parameter is
          expanded.  The value is ‘not’ converted when assigned.

     ‘-r’

          The given NAMEs are marked readonly.  Note that if NAME is a
          special parameter, the readonly attribute can be turned on,
          but cannot then be turned off.

          If the ‘POSIX_BUILTINS’ option is set, the readonly attribute
          is more restrictive: unset variables can be marked readonly
          and cannot then be set; furthermore, the readonly attribute
          cannot be removed from any variable.

          It is still possible to change other attributes of the
          variable though, some of which like ‘-U’ or ‘-Z’ would affect
          the value.  More generally, the readonly attribute should not
          be relied on as a security mechanism.

          Note that in zsh (like in pdksh but unlike most other shells)
          it is still possible to create a local variable of the same
          name as this is considered a different variable (though this
          variable, too, can be marked readonly).  Special variables
          that have been made readonly retain their value and readonly
          attribute when made local.

     ‘-t’

          Tags the named parameters.  Tags only exist to flag the
          parameter for the user’s own purposes — the list of tagged
          parameters can be queried using ‘typeset -t’.  Tags have no
          other use.  Note that the ‘-t’ flag has a different meaning
          when used with ‘-f’; see above.

     ‘-u’

          Convert the result to upper case whenever the parameter is
          expanded.  The value is ‘not’ converted when assigned.  This
          flag has different meanings when used with ‘-f’ or ‘-n’; see
          above.

     ‘-x’

          Mark for automatic export to the environment of subsequently
          executed commands.  If the option ‘GLOBAL_EXPORT’ is set, this
          implies the option ‘-g’, unless ‘+g’ is also explicitly given;
          in other words the parameter is not made local to the
          enclosing function.  This is for compatibility with previous
          versions of zsh.

‘ulimit’ [ ‘-HSa’ ] [ { ‘-bcdfiklmnpqrsTtvwx’ | ‘-N’ RESOURCE } [ LIMIT
] … ]

     Set or display resource limits of the shell and the processes
     started by the shell.  The value of LIMIT can be a number in the
     unit specified below or one of the values ‘unlimited’, which
     removes the limit on the resource, or ‘hard’, which uses the
     current value of the hard limit on the resource.

     By default, only soft limits are manipulated.  If the ‘-H’ flag is
     given use hard limits instead of soft limits.  If the ‘-S’ flag is
     given together with the ‘-H’ flag set both hard and soft limits.

     If no options are used, the file size limit (‘-f’) is assumed.

     If LIMIT is omitted the current value of the specified resources
     are printed.  When more than one resource value is printed, the
     limit name and unit is printed before each value.

     When looping over multiple resources, the shell will abort
     immediately if it detects a badly formed argument.  However, if it
     fails to set a limit for some other reason it will continue trying
     to set the remaining limits.

     Not all the following resources are supported on all systems.
     Running ‘ulimit -a’ will show which are supported.

     ‘-a’

          List all of the current resource limits.

     ‘-b’

          Socket buffer size in bytes (N.B. not kilobytes)

     ‘-c’

          512-byte blocks on the size of core dumps.

     ‘-d’

          Kilobytes on the size of the data segment.

     ‘-e’

          Maximum nice value.

     ‘-f’

          512-byte blocks on the size of files written.

     ‘-i’

          The number of pending signals.

     ‘-k’

          The number of kqueues allocated.

     ‘-l’

          Kilobytes on the size of locked-in memory.

     ‘-m’

          Kilobytes on the size of physical memory.

     ‘-n’

          Open file descriptors.

     ‘-o’

          Maximum number of POSIX thread library objects.

     ‘-p’

          The number of pseudo-terminals.

     ‘-q’

          Bytes in POSIX message queues.

     ‘-r’

          Maximum real time priority.  On some systems where this is not
          available, such as NetBSD, this has the same effect as ‘-T’
          for compatibility with ‘sh’.

     ‘-s’

          Kilobytes on the size of the stack.

     ‘-T’

          The number of simultaneous threads available to the user.

     ‘-t’

          CPU seconds to be used.

     ‘-u’

          The number of processes available to the user.

     ‘-v’

          Kilobytes on the size of virtual memory.  On some systems this
          refers to the limit called ‘address space’.

     ‘-w’

          Kilobytes on the size of swapped out memory.

     ‘-x’

          The number of locks on files.

     ‘-y’

          Maximum size of buffers for pipes/fifos.

     A resource may also be specified by integer in the form ‘-N’
     RESOURCE, where RESOURCE corresponds to the integer defined for the
     resource by the operating system.  This may be used to set the
     limits for resources known to the shell which do not correspond to
     option letters.  Such limits will be shown by number in the output
     of ‘ulimit -a’.

     The number may alternatively be out of the range of limits compiled
     into the shell.  The shell will try to read or write the limit
     anyway, and will report an error if this fails.

‘umask’ [ ‘-S’ ] [ MASK ]

     The umask is set to MASK.  MASK can be either an octal number or a
     symbolic value as described in the ‘chmod(1)’ man page.  If MASK is
     omitted, the current value is printed.  The ‘-S’ option causes the
     mask to be printed as a symbolic value.  Otherwise, the mask is
     printed as an octal number.  Note that in the symbolic form the
     permissions you specify are those which are to be allowed (not
     denied) to the users specified.

‘unalias’ [ ‘-ams’ ] NAME …

     Removes aliases.  This command works the same as ‘unhash -a’,
     except that the ‘-a’ option removes all regular or global aliases,
     or with ‘-s’ all suffix aliases: in this case no NAME arguments may
     appear.  The options ‘-m’ (remove by pattern) and ‘-s’ without ‘-a’
     (remove listed suffix aliases) behave as for ‘unhash -a’.  Note
     that the meaning of ‘-a’ is different between ‘unalias’ and
     ‘unhash’.

‘unfunction’

     Same as ‘unhash -f’.

‘unhash’ [ ‘-adfms’ ] NAME …

     Remove the element named NAME from an internal hash table.  The
     default is remove elements from the command hash table.  The ‘-a’
     option causes ‘unhash’ to remove regular or global aliases; note
     when removing a global aliases that the argument must be quoted to
     prevent it from being expanded before being passed to the command.
     The ‘-s’ option causes ‘unhash’ to remove suffix aliases.  The ‘-f’
     option causes ‘unhash’ to remove shell functions.  The ‘-d’ options
     causes ‘unhash’ to remove named directories.  If the ‘-m’ flag is
     given the arguments are taken as patterns (should be quoted) and
     all elements of the corresponding hash table with matching names
     will be removed.

‘unlimit’ [ ‘-hs’ ] RESOURCE …

     The resource limit for each RESOURCE is set to the hard limit.  If
     the ‘-h’ flag is given and the shell has appropriate privileges,
     the hard resource limit for each RESOURCE is removed.  The
     resources of the shell process are only changed if the ‘-s’ flag is
     given.

     The ‘unlimit’ command is not made available by default when the
     shell starts in a mode emulating another shell.  It can be made
     available with the command ‘zmodload -F zsh/rlimits b:unlimit’.

‘unset’ [ ‘-fmv’ ] [ ‘-n’ ] NAME …

     Each named parameter is unset.  Local parameters remain local even
     if unset; they appear unset within scope, but the previous value
     will still reappear when the scope ends.

     Individual elements of associative array parameters may be unset by
     using subscript syntax on NAME, which should be quoted (or the
     entire command prefixed with ‘noglob’) to protect the subscript
     from filename generation.

     If the ‘-m’ flag is specified the arguments are taken as patterns
     (should be quoted) and all parameters with matching names are
     unset.  Note that this cannot be used when unsetting associative
     array elements, as the subscript will be treated as part of the
     pattern.

     The ‘-v’ flag specifies that NAME refers to parameters.  This is
     the default behaviour.  If the ‘-n’ option is supplied, and NAME is
     a a named reference, NAME will be unset rather than the variable it
     references.

     ‘unset -f’ is equivalent to ‘unfunction’.  The ‘-n’ option has no
     effect with ‘-f’.

‘unsetopt’ [ {‘+|-’}:var:‘options’ | {‘+|-}o’ OPTION_NAME ] [ NAME … ]

     Unset the options for the shell.  All options specified either with
     flags or by name are unset.  If no arguments are supplied, the
     names of all options currently unset are printed.  If the ‘-m’ flag
     is given the arguments are taken as patterns (which should be
     quoted to preserve them from being interpreted as glob patterns),
     and all options with names matching these patterns are unset.

‘vared’

     See *note Zle Builtins: ba.

‘wait’ [ JOB … ]

     Wait for the specified jobs or processes.  If JOB is not given then
     all currently active child processes are waited for.  Each JOB can
     be either a job specification or the process ID of a job in the job
     table.  The exit status from this command is that of the job waited
     for.  If JOB represents an unknown job or process ID, a warning is
     printed (unless the ‘POSIX_BUILTINS’ option is set) and the exit
     status is 127.

     It is possible to wait for recent processes (specified by process
     ID, not by job) that were running in the background even if the
     process has exited.  Typically the process ID will be recorded by
     capturing the value of the variable ‘$!’ immediately after the
     process has been started.  There is a limit on the number of
     process IDs remembered by the shell; this is given by the value of
     the system configuration parameter ‘CHILD_MAX’.  When this limit is
     reached, older process IDs are discarded, least recently started
     processes first.

     Note there is no protection against the process ID wrapping, i.e.
     if the wait is not executed soon enough there is a chance the
     process waited for is the wrong one.  A conflict implies both
     process IDs have been generated by the shell, as other processes
     are not recorded, and that the user is potentially interested in
     both, so this problem is intrinsic to process IDs.

‘whence’ [ ‘-vcwfpamsS’ ] [ ‘-x’ NUM ] NAME …

     For each NAME, indicate how it would be interpreted if used as a
     command name.

     If NAME is not an alias, built-in command, external command, shell
     function, hashed command, or a reserved word, the exit status shall
     be non-zero, and – if ‘-v’, ‘-c’, or ‘-w’ was passed – a message
     will be written to standard output.  (This is different from other
     shells that write that message to standard error.)

     ‘whence’ is most useful when NAME is only the last path component
     of a command, i.e.  does not include a ‘/’; in particular, pattern
     matching only succeeds if just the non-directory component of the
     command is passed.

     ‘-v’

          Produce a more verbose report.

     ‘-c’

          Print the results in a ‘csh’-like format.  This takes
          precedence over ‘-v’.

     ‘-w’

          For each NAME, print NAME‘:’ WORD where WORD is one of
          ‘alias’, ‘builtin’, ‘command’, ‘function’, ‘hashed’,
          ‘reserved’ or ‘none’, according as NAME corresponds to an
          alias, a built-in command, an external command, a shell
          function, a command defined with the ‘hash’ builtin, a
          reserved word, or is not recognised.  This takes precedence
          over ‘-v’ and ‘-c’.

     ‘-f’

          Causes the contents of a shell function to be displayed, which
          would otherwise not happen unless the ‘-c’ flag were used.

     ‘-p’

          Do a path search for NAME even if it is an alias, reserved
          word, shell function or builtin.

     ‘-a’

          Do a search for all occurrences of NAME throughout the command
          path.  Normally only the first occurrence is printed.  When
          combined with ‘-m’, only names appearing in the command hash
          table are searched, but all occurrences of those names are
          printed.

     ‘-m’

          The arguments are taken as patterns (pattern characters should
          be quoted), and the information is displayed for each entry in
          the command hash table matching one of these patterns.  The
          hash table is first refilled, in case of changes to ‘PATH’.

     ‘-s’

          If a pathname contains symlinks, print the symlink-free
          pathname as well.

     ‘-S’

          As ‘-s’, but if the pathname had to be resolved by following
          multiple symlinks, the intermediate steps are printed, too.
          The symlink resolved at each step might be anywhere in the
          path.

     ‘-x’ NUM

          Expand tabs when outputting shell functions using the ‘-c’
          option.  This has the same effect as the ‘-x’ option to the
          ‘functions’ builtin.

‘where’ [ ‘-wpmsS’ ] [ ‘-x’ NUM ] NAME …

     Equivalent to ‘whence -ca’.

‘which’ [ ‘-wpamsS’ ] [ ‘-x’ NUM ] NAME …

     Equivalent to ‘whence -c’.

‘zcompile’ [ ‘-U’ ] [ ‘-z’ | ‘-k’ ] [ ‘-R’ | ‘-M’ ] FILE [ NAME … ]

‘zcompile’ ‘-ca’ [ ‘-m’ ] [ ‘-R’ | ‘-M’ ] FILE [ NAME … ]

‘zcompile -t’ FILE [ NAME … ]

     This builtin command can be used to compile functions or scripts,
     storing the compiled form in a file, and to examine files
     containing the compiled form.  This allows faster autoloading of
     functions and sourcing of scripts by avoiding parsing of the text
     when the files are read.

     The first form (without the ‘-c’, ‘-a’ or ‘-t’ options) creates a
     compiled file.  If only the FILE argument is given, the output file
     has the name FILE‘.zwc’ and will be placed in the same directory as
     the FILE.  The shell will load the compiled file instead of the
     normal function file when the function is autoloaded; see *note
     Autoloading Functions: b9. for a description of how autoloaded
     functions are searched.  The extension ‘.zwc’ stands for ‘zsh word
     code’.

     If there is at least one NAME argument, all the named files are
     compiled into the output FILE given as the first argument.  If FILE
     does not end in ‘.zwc’, this extension is automatically appended.
     Files containing multiple compiled functions are called ‘digest’
     files, and are intended to be used as elements of the ‘FPATH/fpath’
     special array.

     The second form, with the ‘-c’ or ‘-a’ options, writes the compiled
     definitions for all the named functions into FILE.  For ‘-c’, the
     names must be functions currently defined in the shell, not those
     marked for autoloading.  Undefined functions that are marked for
     autoloading may be written by using the ‘-a’ option, in which case
     the ‘fpath’ is searched and the contents of the definition files
     for those functions, if found, are compiled into FILE.  If both
     ‘-c’ and ‘-a’ are given, names of both defined functions and
     functions marked for autoloading may be given.  In either case, the
     functions in files written with the ‘-c’ or ‘-a’ option will be
     autoloaded as if the ‘KSH_AUTOLOAD’ option were unset.

     The reason for handling loaded and not-yet-loaded functions with
     different options is that some definition files for autoloading
     define multiple functions, including the function with the same
     name as the file, and, at the end, call that function.  In such
     cases the output of ‘zcompile -c’ does not include the additional
     functions defined in the file, and any other initialization code in
     the file is lost.  Using ‘zcompile -a’ captures all this extra
     information.

     If the ‘-m’ option is combined with ‘-c’ or ‘-a’, the NAMEs are
     used as patterns and all functions whose names match one of these
     patterns will be written.  If no NAME is given, the definitions of
     all functions currently defined or marked as autoloaded will be
     written.

     Note the second form cannot be used for compiling functions that
     include redirections as part of the definition rather than within
     the body of the function; for example

           fn1() { { ... } >~/logfile }

     can be compiled but

           fn1() { ... } >~/logfile

     cannot.  It is possible to use the first form of ‘zcompile’ to
     compile autoloadable functions that include the full function
     definition instead of just the body of the function.

     The third form, with the ‘-t’ option, examines an existing compiled
     file.  Without further arguments, the names of the original files
     compiled into it are listed.  The first line of output shows the
     version of the shell which compiled the file and how the file will
     be used (i.e.  by reading it directly or by mapping it into
     memory).  With arguments, nothing is output and the return status
     is set to zero if definitions for ‘all’ NAMEs were found in the
     compiled file, and non-zero if the definition for at least one NAME
     was not found.

     Other options:

     ‘-U’

          Aliases are not expanded when compiling the NAMEd files.

     ‘-R’

          When the compiled file is read, its contents are copied into
          the shell’s memory, rather than memory-mapped (see ‘-M’).
          This happens automatically on systems that do not support
          memory mapping.

          When compiling scripts instead of autoloadable functions, it
          is often desirable to use this option; otherwise the whole
          file, including the code to define functions which have
          already been defined, will remain mapped, consequently wasting
          memory.

     ‘-M’

          The compiled file is mapped into the shell’s memory when read.
          This is done in such a way that multiple instances of the
          shell running on the same host will share this mapped file.
          If neither ‘-R’ nor ‘-M’ is given, the ‘zcompile’ builtin
          decides what to do based on the size of the compiled file.

     ‘-k’

     ‘-z’

          These options are used when the compiled file contains
          functions which are to be autoloaded.  If ‘-z’ is given, the
          function will be autoloaded as if the ‘KSH_AUTOLOAD’ option is
          ‘not’ set, even if it is set at the time the compiled file is
          read, while if the ‘-k’ is given, the function will be loaded
          as if ‘KSH_AUTOLOAD’ ‘is’ set.  These options also take
          precedence over any ‘-k’ or ‘-z’ options specified to the
          ‘autoload’ builtin.  If neither of these options is given, the
          function will be loaded as determined by the setting of the
          ‘KSH_AUTOLOAD’ option at the time the compiled file is read.

          These options may also appear as many times as necessary
          between the listed NAMEs to specify the loading style of all
          following functions, up to the next ‘-k’ or ‘-z’.

     The created file always contains two versions of the compiled
     format, one for big-endian machines and one for small-endian
     machines.  The upshot of this is that the compiled file is machine
     independent and if it is read or mapped, only one half of the file
     is actually used (and mapped).

     ‘zformat’

          See *note The zsh/zutil Module: ca.

     ‘zftp’

          See *note The zsh/zftp Module: cb.

     ‘zle’

          See *note Zle Builtins: ba.

     ‘zmodload’ [ ‘-dL’ ] [ ‘-s’ ] [ … ]

     ‘zmodload -F’ [ ‘-alLme’ ‘-P’ PARAM ] MODULE [ [‘+-’]:var:‘feature’
     … ]

     ‘zmodload -e’ [ ‘-A’ ] [ … ]

     ‘zmodload’ [ ‘-a’ [ ‘-bcpf’ [ ‘-I’ ] ] ] [ ‘-iL’ ] …

     ‘zmodload’ ‘-u’ [ ‘-abcdpf’ [ ‘-I’ ] ] [ ‘-iL’ ] …

     ‘zmodload’ ‘-A’ [ ‘-L’ ] [ MODALIAS[‘=’MODULE] … ]

     ‘zmodload’ ‘-R’ MODALIAS …

          Performs operations relating to zsh’s loadable modules.
          Loading of modules while the shell is running (‘dynamical
          loading’) is not available on all operating systems, or on all
          installations on a particular operating system, although the
          ‘zmodload’ command itself is always available and can be used
          to manipulate modules built into versions of the shell
          executable without dynamical loading.

          Without arguments the names of all currently loaded binary
          modules are printed.  The ‘-L’ option causes this list to be
          in the form of a series of ‘zmodload’ commands.  Forms with
          arguments are:

          ‘zmodload’ [ ‘-is’ ] NAME …

          ‘zmodload’ ‘-u’ [ ‘-i’ ] NAME …

               In the simplest case, ‘zmodload’ loads a binary module.
               The module must be in a file with a name consisting of
               the specified NAME followed by a standard suffix, usually
               ‘.so’ (‘.sl’ on HPUX). If the module to be loaded is
               already loaded the duplicate module is ignored.  If
               ‘zmodload’ detects an inconsistency, such as an invalid
               module name or circular dependency list, the current code
               block is aborted.  If it is available, the module is
               loaded if necessary, while if it is not available,
               non-zero status is silently returned.  The option ‘-i’ is
               accepted for compatibility but has no effect.

               The NAMEd module is searched for in the same way a
               command is, using ‘$module_path’ instead of ‘$path’.
               However, the path search is performed even when the
               module name contains a ‘/’, which it usually does.  There
               is no way to prevent the path search.

               If the module supports features (see below), ‘zmodload’
               tries to enable all features when loading a module.  If
               the module was successfully loaded but not all features
               could be enabled, ‘zmodload’ returns status 2.

               If the option ‘-s’ is given, no error is printed if the
               module was not available (though other errors indicating
               a problem with the module are printed).  The return
               status indicates if the module was loaded.  This is
               appropriate if the caller considers the module optional.

               With ‘-u’, ‘zmodload’ unloads modules.  The same NAME
               must be given that was given when the module was loaded,
               but it is not necessary for the module to exist in the
               file system.  The ‘-i’ option suppresses the error if the
               module is already unloaded (or was never loaded).

               Each module has a boot and a cleanup function.  The
               module will not be loaded if its boot function fails.
               Similarly a module can only be unloaded if its cleanup
               function runs successfully.

          ‘zmodload -F’ [ ‘-almLe’ ‘-P’ PARAM ] MODULE [
          [‘+-’]:var:‘feature’ … ]

               ‘zmodload -F’ allows more selective control over the
               features provided by modules.  With no options apart from
               ‘-F’, the module named MODULE is loaded, if it was not
               already loaded, and the list of FEATUREs is set to the
               required state.  If no FEATUREs are specified, the module
               is loaded, if it was not already loaded, but the state of
               features is unchanged.  Each feature may be preceded by a
               ‘+’ to turn the feature on, or ‘-’ to turn it off; the
               ‘+’ is assumed if neither character is present.  Any
               feature not explicitly mentioned is left in its current
               state; if the module was not previously loaded this means
               any such features will remain disabled.  The return
               status is zero if all features were set, 1 if the module
               failed to load, and 2 if some features could not be set
               (for example, a parameter couldn’t be added because there
               was a different parameter of the same name) but the
               module was loaded.

               The standard features are builtins, conditions,
               parameters and math functions; these are indicated by the
               prefix ‘b:’, ‘c:’ (‘C:’ for an infix condition), ‘p:’ and
               ‘f:’, respectively, followed by the name that the
               corresponding feature would have in the shell.  For
               example, ‘b:strftime’ indicates a builtin named
               ‘strftime’ and ‘p:EPOCHSECONDS’ indicates a parameter
               named ‘EPOCHSECONDS’.  The module may provide other
               (‘abstract’) features of its own as indicated by its
               documentation; these have no prefix.

               With ‘-l’ or ‘-L’, features provided by the module are
               listed.  With ‘-l’ alone, a list of features together
               with their states is shown, one feature per line.  With
               ‘-L’ alone, a ‘zmodload -F’ command that would cause
               enabled features of the module to be turned on is shown.
               With ‘-lL’, a ‘zmodload -F’ command that would cause all
               the features to be set to their current state is shown.
               If one of these combinations is given with the option
               ‘-P’ PARAM then the parameter PARAM is set to an array of
               features, either features together with their state or
               (if ‘-L’ alone is given) enabled features.

               With the option ‘-L’ the module name may be omitted; then
               a list of all enabled features for all modules providing
               features is printed in the form of ‘zmodload -F’
               commands.  If ‘-l’ is also given, the state of both
               enabled and disabled features is output in that form.

               A set of features may be provided together with ‘-l’ or
               ‘-L’ and a module name; in that case only the state of
               those features is considered.  Each feature may be
               preceded by ‘+’ or ‘-’ but the character has no effect.
               If no set of features is provided, all features are
               considered.

               With ‘-e’, the command first tests that the module is
               loaded; if it is not, status 1 is returned.  If the
               module is loaded, the list of features given as an
               argument is examined.  Any feature given with no prefix
               is simply tested to see if the module provides it; any
               feature given with a prefix ‘+’ or ‘-’ is tested to see
               if is provided and in the given state.  If the tests on
               all features in the list succeed, status 0 is returned,
               else status 1.

               With ‘-m’, each entry in the given list of features is
               taken as a pattern to be matched against the list of
               features provided by the module.  An initial ‘+’ or ‘-’
               must be given explicitly.  This may not be combined with
               the ‘-a’ option as autoloads must be specified
               explicitly.

               With ‘-a’, the given list of features is marked for
               autoload from the specified module, which may not yet be
               loaded.  An optional ‘+’ may appear before the feature
               name.  If the feature is prefixed with ‘-’, any existing
               autoload is removed.  The options ‘-l’ and ‘-L’ may be
               used to list autoloads.  Autoloading is specific to
               individual features; when the module is loaded only the
               requested feature is enabled.  Autoload requests are
               preserved if the module is subsequently unloaded until an
               explicit ‘zmodload -Fa’ MODULE ‘-’FEATURE is issued.  It
               is not an error to request an autoload for a feature of a
               module that is already loaded.

               When the module is loaded each autoload is checked
               against the features actually provided by the module; if
               the feature is not provided the autoload request is
               deleted.  A warning message is output; if the module is
               being loaded to provide a different feature, and that
               autoload is successful, there is no effect on the status
               of the current command.  If the module is already loaded
               at the time when ‘zmodload -Fa’ is run, an error message
               is printed and status 1 returned.

               ‘zmodload -Fa’ can be used with the ‘-l’, ‘-L’, ‘-e’ and
               ‘-P’ options for listing and testing the existence of
               autoloadable features.  In this case ‘-l’ is ignored if
               ‘-L’ is specified.  ‘zmodload -FaL’ with no module name
               lists autoloads for all modules.

               Note that only standard features as described above can
               be autoloaded; other features require the module to be
               loaded before enabling.

          ‘zmodload’ ‘-d’ [ ‘-L’ ] [ NAME ]

          ‘zmodload’ ‘-d’ NAME DEP …

          ‘zmodload’ ‘-ud’ NAME [ DEP … ]

               The ‘-d’ option can be used to specify module
               dependencies.  The modules named in the second and
               subsequent arguments will be loaded before the module
               named in the first argument.

               With ‘-d’ and one argument, all dependencies for that
               module are listed.  With ‘-d’ and no arguments, all
               module dependencies are listed.  This listing is by
               default in a Makefile-like format.  The ‘-L’ option
               changes this format to a list of ‘zmodload -d’ commands.

               If ‘-d’ and ‘-u’ are both used, dependencies are removed.
               If only one argument is given, all dependencies for that
               module are removed.

          ‘zmodload’ ‘-ab’ [ ‘-L’ ]

          ‘zmodload’ ‘-ab’ [ ‘-i’ ] NAME [ BUILTIN … ]

          ‘zmodload’ ‘-ub’ [ ‘-i’ ] BUILTIN …

               The ‘-ab’ option defines autoloaded builtins.  It defines
               the specified BUILTINs.  When any of those builtins is
               called, the module specified in the first argument is
               loaded and all its features are enabled (for selective
               control of features use ‘zmodload -F -a’ as described
               above).  If only the NAME is given, one builtin is
               defined, with the same name as the module.  ‘-i’
               suppresses the error if the builtin is already defined or
               autoloaded, but not if another builtin of the same name
               is already defined.

               With ‘-ab’ and no arguments, all autoloaded builtins are
               listed, with the module name (if different) shown in
               parentheses after the builtin name.  The ‘-L’ option
               changes this format to a list of ‘zmodload -a’ commands.

               If ‘-b’ is used together with the ‘-u’ option, it removes
               builtins previously defined with ‘-ab’.  This is only
               possible if the builtin is not yet loaded.  ‘-i’
               suppresses the error if the builtin is already removed
               (or never existed).

               Autoload requests are retained if the module is
               subsequently unloaded until an explicit ‘zmodload -ub’
               BUILTIN is issued.

          ‘zmodload’ ‘-ac’ [ ‘-IL’ ]

          ‘zmodload’ ‘-ac’ [ ‘-iI’ ] NAME [ COND … ]

          ‘zmodload’ ‘-uc’ [ ‘-iI’ ] COND …

               The ‘-ac’ option is used to define autoloaded condition
               codes.  The COND strings give the names of the conditions
               defined by the module.  The optional ‘-I’ option is used
               to define infix condition names.  Without this option
               prefix condition names are defined.

               If given no condition names, all defined names are listed
               (as a series of ‘zmodload’ commands if the ‘-L’ option is
               given).

               The ‘-uc’ option removes definitions for autoloaded
               conditions.

          ‘zmodload’ ‘-ap’ [ ‘-L’ ]

          ‘zmodload’ ‘-ap’ [ ‘-i’ ] NAME [ PARAMETER … ]

          ‘zmodload’ ‘-up’ [ ‘-i’ ] PARAMETER …

               The ‘-p’ option is like the ‘-b’ and ‘-c’ options, but
               makes ‘zmodload’ work on autoloaded parameters instead.

          ‘zmodload’ ‘-af’ [ ‘-L’ ]

          ‘zmodload’ ‘-af’ [ ‘-i’ ] NAME [ FUNCTION … ]

          ‘zmodload’ ‘-uf’ [ ‘-i’ ] FUNCTION …

               The ‘-f’ option is like the ‘-b’, ‘-p’, and ‘-c’ options,
               but makes ‘zmodload’ work on autoloaded math functions
               instead.

          ‘zmodload’ ‘-a’ [ ‘-L’ ]

          ‘zmodload’ ‘-a’ [ ‘-i’ ] NAME [ BUILTIN … ]

          ‘zmodload’ ‘-ua’ [ ‘-i’ ] BUILTIN …

               Equivalent to ‘-ab’ and ‘-ub’.

          ‘zmodload -e’ [ ‘-A’ ] [ STRING … ]

               The ‘-e’ option without arguments lists all loaded
               modules; if the ‘-A’ option is also given, module aliases
               corresponding to loaded modules are also shown.  If
               arguments are provided, nothing is printed; the return
               status is set to zero if all STRINGs given as arguments
               are names of loaded modules and to one if at least on
               STRING is not the name of a loaded module.  This can be
               used to test for the availability of things implemented
               by modules.  In this case, any aliases are automatically
               resolved and the ‘-A’ flag is not used.

          ‘zmodload’ ‘-A’ [ ‘-L’ ] [ MODALIAS[‘=’MODULE] … ]

               For each argument, if both MODALIAS and MODULE are given,
               define MODALIAS to be an alias for the module MODULE.  If
               the module MODALIAS is ever subsequently requested,
               either via a call to ‘zmodload’ or implicitly, the shell
               will attempt to load MODULE instead.  If MODULE is not
               given, show the definition of MODALIAS.  If no arguments
               are given, list all defined module aliases.  When
               listing, if the ‘-L’ flag was also given, list the
               definition as a ‘zmodload’ command to recreate the alias.

               The existence of aliases for modules is completely
               independent of whether the name resolved is actually
               loaded as a module: while the alias exists, loading and
               unloading the module under any alias has exactly the same
               effect as using the resolved name, and does not affect
               the connection between the alias and the resolved name
               which can be removed either by ‘zmodload -R’ or by
               redefining the alias.  Chains of aliases (i.e.  where the
               first resolved name is itself an alias) are valid so long
               as these are not circular.  As the aliases take the same
               format as module names, they may include path separators:
               in this case, there is no requirement for any part of the
               path named to exist as the alias will be resolved first.
               For example, ‘any/old/alias’ is always a valid alias.

               Dependencies added to aliased modules are actually added
               to the resolved module; these remain if the alias is
               removed.  It is valid to create an alias whose name is
               one of the standard shell modules and which resolves to a
               different module.  However, if a module has dependencies,
               it will not be possible to use the module name as an
               alias as the module will already be marked as a loadable
               module in its own right.

               Apart from the above, aliases can be used in the
               ‘zmodload’ command anywhere module names are required.
               However, aliases will not be shown in lists of loaded
               modules with a bare ‘zmodload’.

          ‘zmodload’ ‘-R’ MODALIAS …

               For each MODALIAS argument that was previously defined as
               a module alias via ‘zmodload -A’, delete the alias.  If
               any was not defined, an error is caused and the remainder
               of the line is ignored.

          Note that ‘zsh’ makes no distinction between modules that were
          linked into the shell and modules that are loaded dynamically.
          In both cases this builtin command has to be used to make
          available the builtins and other things defined by modules
          (unless the module is autoloaded on these definitions).  This
          is true even for systems that don’t support dynamic loading of
          modules.

     ‘zparseopts’

          See *note The zsh/zutil Module: ca.

     ‘zprof’

          See *note The zsh/zprof Module: cc.

     ‘zpty’

          See *note The zsh/zpty Module: cd.

     ‘zregexparse’

          See *note The zsh/zutil Module: ca.

     ‘zsocket’

          See *note The zsh/net/socket Module: ce.

     ‘zstyle’

          See *note The zsh/zutil Module: ca.

     ‘ztcp’

          See *note The zsh/net/tcp Module: cf.


File: zsh.info,  Node: Zsh Line Editor,  Next: Completion Widgets,  Prev: Shell Builtin Commands,  Up: Top

17 Zsh Line Editor
******************

* Menu:

* Description: Description<3>.
* Keymaps::
* Zle Builtins::
* Zle Widgets::
* User-Defined Widgets::
* Standard Widgets::
* Terminal Extensions::
* Character Highlighting::
* Cursor Shape and Color::


File: zsh.info,  Node: Description<3>,  Next: Keymaps,  Up: Zsh Line Editor

17.1 Description
================

If the ‘ZLE’ option is set (which it is by default in interactive
shells) and the shell input is attached to the terminal, the user is
able to edit command lines.

There are two display modes.  The first, multiline mode, is the default.
It only works if the ‘TERM’ parameter is set to a valid terminal type
that can move the cursor up.  The second, single line mode, is used if
‘TERM’ is invalid or incapable of moving the cursor up, or if the
‘SINGLE_LINE_ZLE’ option is set.  ..  index:: single: SINGLE_LINE_ZLE,
use of; Program

This mode is similar to ‘ksh’, and uses no termcap sequences.  If ‘TERM’
is “emacs”, the ‘ZLE’ option will be unset by default.

The parameters ‘BAUD’, ‘COLUMNS’, and ‘LINES’ are also used by the line
editor.  See *note Parameters Used by the Shell: 11.

The parameter ‘zle_highlight’ is also used by the line editor; see *note
Character Highlighting: 60.  Highlighting of special characters and the
region between the cursor and the mark (as set with ‘set-mark-command’
in Emacs mode, or by ‘visual-mode’ in Vi mode) is enabled by default;
consult this reference for more information.  Irascible conservatives
will wish to know that all highlighting may be disabled by the following
setting:

      zle_highlight=(none)

In many places, references are made to the ‘numeric argument’.  This can
by default be entered in emacs mode by holding the alt key and typing a
number, or pressing escape before each digit, and in vi command mode by
typing the number before entering a command.  Generally the numeric
argument causes the next command entered to be repeated the specified
number of times, unless otherwise noted below; this is implemented by
the ‘digit-argument’ widget.  See also *note Arguments: d3. for some
other ways the numeric argument can be modified.


File: zsh.info,  Node: Keymaps,  Next: Zle Builtins,  Prev: Description<3>,  Up: Zsh Line Editor

17.2 Keymaps
============

A keymap in ZLE contains a set of bindings between key sequences and ZLE
commands.  The empty key sequence cannot be bound.

There can be any number of keymaps at any time, and each keymap has one
or more names.  If all of a keymap’s names are deleted, it disappears.
..  index:: single: bindkey, use of; Function

‘bindkey’ can be used to manipulate keymap names.

Initially, there are eight keymaps:

‘emacs’

     EMACS emulation

‘viins’

     vi emulation - insert mode

‘vicmd’

     vi emulation - command mode

‘viopp’

     vi emulation - operator pending

‘visual’

     vi emulation - selection active

‘isearch’

     incremental search mode

‘command’

     read a command name

‘.safe’

     fallback keymap

The ‘.safe’ keymap is special.  It can never be altered, and the name
can never be removed.  However, it can be linked to other names, which
can be removed.  In the future other special keymaps may be added; users
should avoid using names beginning with ‘.’ for their own keymaps.

In addition to these names, either ‘emacs’ or ‘viins’ is also linked to
the name ‘main’.  If one of the ‘VISUAL’ or ‘EDITOR’ environment
variables contain the string ‘vi’ when the shell starts up then it will
be ‘viins’, otherwise it will be ‘emacs’.  ‘bindkey’’s ‘-e’ and ‘-v’
options provide a convenient way to override this default choice.

When the editor starts up, it will select the ‘main’ keymap.  If that
keymap doesn’t exist, it will use ‘.safe’ instead.

In the ‘.safe’ keymap, each single key is bound to ‘self-insert’, except
for ^J (line feed) and ^M (return) which are bound to ‘accept-line’.
This is deliberately not pleasant to use; if you are using it, it means
you deleted the main keymap, and you should put it back.

* Menu:

* Reading Commands::
* Local Keymaps::


File: zsh.info,  Node: Reading Commands,  Next: Local Keymaps,  Up: Keymaps

17.2.1 Reading Commands
-----------------------

When ZLE is reading a command from the terminal, it may read a sequence
that is bound to some command and is also a prefix of a longer bound
string.  In this case ZLE will wait a certain time to see if more
characters are typed, and if not (or they don’t match any longer string)
it will execute the binding.  This timeout is defined by the
‘KEYTIMEOUT’ parameter; its default is 0.4 sec.  There is no timeout if
the prefix string is not itself bound to a command.

The key timeout is also applied when ZLE is reading the bytes from a
multibyte character string when it is in the appropriate mode.  (This
requires that the shell was compiled with multibyte mode enabled;
typically also the locale has characters with the UTF-8 encoding,
although any multibyte encoding known to the operating system is
supported.)  If the second or a subsequent byte is not read within the
timeout period, the shell acts as if ‘?’ were typed and resets the input
state.

As well as ZLE commands, key sequences can be bound to other strings, by
using ‘bindkey -s’.  When such a sequence is read, the replacement
string is pushed back as input, and the command reading process starts
again using these fake keystrokes.  This input can itself invoke further
replacement strings, but in order to detect loops the process will be
stopped if there are twenty such replacements without a real command
being read.

A key sequence typed by the user can be turned into a command name for
use in user-defined widgets with the ‘read-command’ widget, described in
*note Miscellaneous: d6.


File: zsh.info,  Node: Local Keymaps,  Prev: Reading Commands,  Up: Keymaps

17.2.2 Local Keymaps
--------------------

While for normal editing a single keymap is used exclusively, in many
modes a local keymap allows for some keys to be customised.  For
example, in an incremental search mode, a binding in the ‘isearch’
keymap will override a binding in the ‘main’ keymap but all keys that
are not overridden can still be used.

If a key sequence is defined in a local keymap, it will hide a key
sequence in the global keymap that is a prefix of that sequence.  An
example of this occurs with the binding of ‘iw’ in ‘viopp’ as this hides
the binding of ‘i’ in ‘vicmd’.  However, a longer sequence in the global
keymap that shares the same prefix can still apply so for example the
binding of ‘^Xa’ in the global keymap will be unaffected by the binding
of ‘^Xb’ in the local keymap.


File: zsh.info,  Node: Zle Builtins,  Next: Zle Widgets,  Prev: Keymaps,  Up: Zsh Line Editor

17.3 Zle Builtins
=================

The ZLE module contains three related builtin commands.  The ‘bindkey’
command manipulates keymaps and key bindings; the ‘vared’ command
invokes ZLE on the value of a shell parameter; and the ‘zle’ command
manipulates editing widgets and allows command line access to ZLE
commands from within shell functions.

‘bindkey’ [ OPTIONS ] ‘-l’ [ ‘-L’ ] [ KEYMAP … ]

‘bindkey’ [ OPTIONS ] ‘-d’

‘bindkey’ [ OPTIONS ] ‘-D’ KEYMAP …

‘bindkey’ [ OPTIONS ] ‘-A’ OLD-KEYMAP NEW-KEYMAP

‘bindkey’ [ OPTIONS ] ‘-N’ NEW-KEYMAP [ OLD-KEYMAP ]

‘bindkey’ [ OPTIONS ] ‘-m’

‘bindkey’ [ OPTIONS ] ‘-r’ IN-STRING …

‘bindkey’ [ OPTIONS ] ‘-s’ IN-STRING OUT-STRING …

‘bindkey’ [ OPTIONS ] IN-STRING COMMAND …

‘bindkey’ [ OPTIONS ] [ IN-STRING ]

     ‘bindkey’’s options can be divided into three categories: keymap
     selection for the current command, operation selection, and others.
     The keymap selection options are:

     ‘-e’

          Selects keymap ‘emacs’ for any operations by the current
          command, and also links ‘emacs’ to ‘main’ so that it is
          selected by default the next time the editor starts.

     ‘-v’

          Selects keymap ‘viins’ for any operations by the current
          command, and also links ‘viins’ to ‘main’ so that it is
          selected by default the next time the editor starts.

     ‘-a’

          Selects keymap ‘vicmd’ for any operations by the current
          command.

     ‘-M’ KEYMAP

          The KEYMAP specifies a keymap name that is selected for any
          operations by the current command.

     If a keymap selection is required and none of the options above are
     used, the ‘main’ keymap is used.  Some operations do not permit a
     keymap to be selected, namely:

     ‘-l’

          List all existing keymap names; if any arguments are given,
          list just those keymaps.

          If the ‘-L’ option is also used, list in the form of ‘bindkey’
          commands to create or link the keymaps.  ‘bindkey -lL main
          ``shows which keymap is linked to’ main‘‘, if any, and hence
          if the standard emacs or vi emulation is in effect.  This
          option does not show the ‘.safe’ keymap because it cannot be
          created in that fashion; however, neither is ‘bindkey -lL
          .safe’ reported as an error, it simply outputs nothing.

     ‘-d’

          Delete all existing keymaps and reset to the default state.

     ‘-D’ KEYMAP …

          Delete the named KEYMAPs.

     ‘-A’ OLD-KEYMAP NEW-KEYMAP

          Make the NEW-KEYMAP name an alias for OLD-KEYMAP, so that both
          names refer to the same keymap.  The names have equal
          standing; if either is deleted, the other remains.  If there
          is already a keymap with the NEW-KEYMAP name, it is deleted.

     ‘-N’ NEW-KEYMAP [ OLD-KEYMAP ]

          Create a new keymap, named NEW-KEYMAP.  If a keymap already
          has that name, it is deleted.  If an OLD-KEYMAP name is given,
          the new keymap is initialized to be a duplicate of it,
          otherwise the new keymap will be empty.

     To use a newly created keymap, it should be linked to ‘main’.
     Hence the sequence of commands to create and use a new keymap
     ‘mymap’ initialized from the ‘emacs’ keymap (which remains
     unchanged) is:

           bindkey -N mymap emacs
           bindkey -A mymap main

     Note that while ‘bindkey -A’ NEWMAP ‘main’ will work when NEWMAP is
     ‘emacs’ or ‘viins’, it will not work for ‘vicmd’, as switching from
     vi insert to command mode becomes impossible.

     The following operations act on the ‘main’ keymap if no keymap
     selection option was given:

     ‘-m’

          Add the built-in set of meta-key bindings to the selected
          keymap.  Only keys that are unbound or bound to ‘self-insert’
          are affected.

     ‘-r’ IN-STRING …

          Unbind the specified IN-STRINGs in the selected keymap.  This
          is exactly equivalent to binding the strings to
          ‘undefined-key’.

          When ‘-R’ is also used, interpret the IN-STRINGs as ranges.

          When ‘-p’ is also used, the IN-STRINGs specify prefixes.  Any
          binding that has the given IN-STRING as a prefix, not
          including the binding for the IN-STRING itself, if any, will
          be removed.  For example,

                bindkey -rpM viins '^['

          will remove all bindings in the vi-insert keymap beginning
          with an escape character (probably cursor keys), but leave the
          binding for the escape character itself (probably
          ‘vi-cmd-mode’).  This is incompatible with the option ‘-R’.

     ‘-s’ IN-STRING OUT-STRING …

          Bind each IN-STRING to each OUT-STRING.  When IN-STRING is
          typed, OUT-STRING will be pushed back and treated as input to
          the line editor.  When ‘-R’ is also used, interpret the
          IN-STRINGs as ranges.

          Note that both IN-STRING and OUT-STRING are subject to the
          same form of interpretation, as described below.

     IN-STRING COMMAND …

          Bind each IN-STRING to each COMMAND.  When ‘-R’ is used,
          interpret the IN-STRINGs as ranges.

     [ IN-STRING ]

          List key bindings.  If an IN-STRING is specified, the binding
          of that string in the selected keymap is displayed.
          Otherwise, all key bindings in the selected keymap are
          displayed.  (As a special case, if the ‘-e’ or ‘-v’ option is
          used alone, the keymap is ‘not’ displayed - the implicit
          linking of keymaps is the only thing that happens.)

          When the option ‘-p’ is used, the IN-STRING must be present.
          The listing shows all bindings which have the given key
          sequence as a prefix, not including any bindings for the key
          sequence itself.

          When the ‘-L’ option is used, the list is in the form of
          ‘bindkey’ commands to create the key bindings.

     When the ‘-R’ option is used as noted above, a valid range consists
     of two characters, with an optional ‘-’ between them.  All
     characters between the two specified, inclusive, are bound as
     specified.

     For either IN-STRING or OUT-STRING, the following escape sequences
     are recognised:

     ‘\a’

          bell character

     ‘\b’

          backspace

     ‘\e’, ‘\E’

          escape

     ‘\f’

          form feed

     ‘\n’

          linefeed (newline)

     ‘\r’

          carriage return

     ‘\t’

          horizontal tab

     ‘\v’

          vertical tab

     ‘\’NNN

          character code in octal

     ‘\x’NN

          character code in hexadecimal

     ‘\u’NNNN

          unicode character code in hexadecimal

     ‘\U’NNNNNNNN

          unicode character code in hexadecimal

     ‘\M[-’]:var:‘X’

          character with meta bit set

     ‘\C[-’]:var:‘X’

          control character

     ‘^’X

          control character

     In all other cases, ‘\’ escapes the following character.  Delete is
     written as ‘^?’.  Note that ‘\M^?’ and ‘^\M?’ are not the same, and
     that (unlike emacs), the bindings ‘\M-’X and ‘\e’X are entirely
     distinct, although they are initialized to the same bindings by
     ‘bindkey -m’.

‘vared’ [ ‘-Aacghe’ ] [ ‘-p’ PROMPT ] [ ‘-r’ RPROMPT ]

          [ ‘-M’ MAIN-KEYMAP ] [ ‘-m’ VICMD-KEYMAP ]

          [ ‘-i’ INIT-WIDGET ] [ ‘-f’ FINISH-WIDGET ]

          [ ‘-t’ TTY ] NAME

     The value of the parameter NAME is loaded into the edit buffer, and
     the line editor is invoked.  When the editor exits, NAME is set to
     the string value returned by the editor.  When the ‘-c’ flag is
     given, the parameter is created if it doesn’t already exist.  The
     ‘-a’ flag may be given with ‘-c’ to create an array parameter, or
     the ‘-A’ flag to create an associative array.  If the type of an
     existing parameter does not match the type to be created, the
     parameter is unset and recreated.  The ‘-g’ flag may be given to
     suppress warnings from the ‘WARN_CREATE_GLOBAL’ and
     ‘WARN_NESTED_VAR’ options.

     If an array or array slice is being edited, separator characters as
     defined in ‘$IFS’ will be shown quoted with a backslash, as will
     backslashes themselves.  Conversely, when the edited text is split
     into an array, a backslash quotes an immediately following
     separator character or backslash; no other special handling of
     backslashes, or any handling of quotes, is performed.

     Individual elements of existing array or associative array
     parameters may be edited by using subscript syntax on NAME.  New
     elements are created automatically, even without ‘-c’.

     If the ‘-p’ flag is given, the following string will be taken as
     the prompt to display at the left.  If the ‘-r’ flag is given, the
     following string gives the prompt to display at the right.  If the
     ‘-h’ flag is specified, the history can be accessed from ZLE. If
     the ‘-e’ flag is given, typing ‘^D’ (Control-D) in an empty buffer
     causes ‘vared’ to exit immediately with a non-zero return value.

     The ‘-M’ option gives a keymap to link to the ‘main’ keymap during
     editing, and the ‘-m’ option gives a keymap to link to the ‘vicmd’
     keymap during editing.  For vi-style editing, this allows a pair of
     keymaps to override ‘viins’ and ‘vicmd’.  For emacs-style editing,
     only ‘-M’ is normally needed but the ‘-m’ option may still be used.
     On exit, the previous keymaps will be restored.

     ‘Vared’ calls the usual ‘zle-line-init’ and ‘zle-line-finish’ hooks
     before and after it takes control.  Using the ‘-i’ and ‘-f’
     options, it is possible to replace these with other custom widgets.

     If ‘-t’ TTY is given, TTY is the name of a terminal device to be
     used instead of the default ‘/dev/tty’.  If TTY does not refer to a
     terminal an error is reported.

‘zle’

‘zle’ ‘-l’ [ ‘-L’ | ‘-a’ ] [ STRING … ]

‘zle’ ‘-D’ WIDGET …

‘zle’ ‘-A’ OLD-WIDGET NEW-WIDGET

‘zle’ ‘-N’ WIDGET [ FUNCTION ]

‘zle’ ‘-f’ FLAG [ FLAG… ]

‘zle’ ‘-C’ WIDGET COMPLETION-WIDGET FUNCTION

‘zle’ ‘-R’ [ ‘-c’ ] [ DISPLAY-STRING ] [ STRING … ]

‘zle’ ‘-M’ STRING

‘zle’ ‘-U’ STRING

‘zle’ ‘-K’ KEYMAP

‘zle’ ‘-F’ [ ‘-L’ | ‘-w’ ] [ FD [ HANDLER ] ]

‘zle’ ‘-I’

‘zle’ ‘-T’ [ ‘tc’ FUNCTION | ‘-r’ ‘tc’ | ‘-L’ ]

‘zle’ WIDGET [ ‘-n’ NUM ] [ ‘-f’ FLAG ] [ ‘-Nw’ ] [ ‘-K’ KEYMAP ] ARGS …

     The ‘zle’ builtin performs a number of different actions concerning
     ZLE.

     With no options and no arguments, only the return status will be
     set.  It is zero if ZLE is currently active and widgets could be
     invoked using this builtin command and non-zero otherwise.  Note
     that even if non-zero status is returned, zle may still be active
     as part of the completion system; this does not allow direct calls
     to ZLE widgets.

     Otherwise, which operation it performs depends on its options:

     ‘-l’ [ ‘-L’ | ‘-a’ ] [ STRING ]

          List all existing user-defined widgets.  If the ‘-L’ option is
          used, list in the form of ‘zle’ commands to create the
          widgets.

          When combined with the ‘-a’ option, all widget names are
          listed, including the builtin ones.  In this case the ‘-L’
          option is ignored.

          If at least one STRING is given, and ‘-a’ is present or ‘-L’
          is not used, nothing will be printed.  The return status will
          be zero if all STRINGs are names of existing widgets and
          non-zero if at least one STRING is not a name of a defined
          widget.  If ‘-a’ is also present, all widget names are used
          for the comparison including builtin widgets, else only
          user-defined widgets are used.

          If at least one STRING is present and the ‘-L’ option is used,
          user-defined widgets matching any STRING are listed in the
          form of ‘zle’ commands to create the widgets.

     ‘-D’ WIDGET …

          Delete the named WIDGETs.

     ‘-A’ OLD-WIDGET NEW-WIDGET

          Make the NEW-WIDGET name an alias for OLD-WIDGET, so that both
          names refer to the same widget.  The names have equal
          standing; if either is deleted, the other remains.  If there
          is already a widget with the NEW-WIDGET name, it is deleted.

     ‘-N’ WIDGET [ FUNCTION ]

          Create a user-defined widget.  If there is already a widget
          with the specified name, it is overwritten.  When the new
          widget is invoked from within the editor, the specified shell
          FUNCTION is called.  If no function name is specified, it
          defaults to the same name as the widget.  For further
          information, see *note Zle Widgets: d8.

     ‘-f’ FLAG [ FLAG… ]

          Set various flags on the running widget.  Possible values for
          FLAG are:

          ‘yank’ for indicating that the widget has yanked text into the
          buffer.  If the widget is wrapping an existing internal
          widget, no further action is necessary, but if it has inserted
          the text manually, then it should also take care to set
          ‘YANK_START’ and ‘YANK_END’ correctly.  ‘yankbefore’ does the
          same but is used when the yanked text appears after the
          cursor.

          ‘kill’ for indicating that text has been killed into the
          cutbuffer.  When repeatedly invoking a kill widget, text is
          appended to the cutbuffer instead of replacing it, but when
          wrapping such widgets, it is necessary to call ‘zle -f kill’
          to retain this effect.

          ‘vichange’ for indicating that the widget represents a vi
          change that can be repeated as a whole with
          ‘vi-repeat-change’.  The flag should be set early in the
          function before inspecting the value of ‘NUMERIC’ or invoking
          other widgets.  This has no effect for a widget invoked from
          insert mode.  If insert mode is active when the widget
          finishes, the change extends until next returning to command
          mode.

     ‘-C’ WIDGET COMPLETION-WIDGET FUNCTION

          Create a user-defined completion widget named WIDGET.  The
          completion widget will behave like the built-in
          completion-widget whose name is given as COMPLETION-WIDGET.
          To generate the completions, the shell function FUNCTION will
          be called.  For further information, see ‘zshcompwid’.

     ‘-R’ [ ‘-c’ ] [ DISPLAY-STRING ] [ STRING … ]

          Redisplay the command line.  If a DISPLAY-STRING is given and
          not empty, this is shown in the status line (immediately below
          the line being edited).

          If the optional STRINGs are given they are listed below the
          prompt in the same way as completion lists are printed.  If no
          STRINGs are given but the ‘-c’ option is used such a list is
          cleared.

          Note that immediately after returning from running widgets,
          the command line will be redisplayed and the strings displayed
          will be erased.  Therefore, this option is only useful for
          widgets that do not exit immediately after using it.

          This command can safely be called outside user defined
          widgets; if zle is active, the display will be refreshed,
          while if zle is not active, the command has no effect.  In
          this case there will usually be no other arguments.

          The status is zero if zle was active, else one.

     ‘-M’ STRING

          As with the ‘-R’ option, the STRING will be displayed below
          the command line; unlike the ‘-R’ option, the string will not
          be put into the status line but will instead be printed
          normally below the prompt.  This means that the STRING will
          still be displayed after the widget returns (until it is
          overwritten by subsequent commands).

     ‘-U’ STRING

          This pushes the characters in the STRING onto the input stack
          of ZLE. After the widget currently executed finishes ZLE will
          behave as if the characters in the STRING were typed by the
          user.

          As ZLE uses a stack, if this option is used repeatedly the
          last string pushed onto the stack will be processed first.
          However, the characters in each STRING will be processed in
          the order in which they appear in the string.

     ‘-K’ KEYMAP

          Selects the keymap named KEYMAP.  An error message will be
          displayed if there is no such keymap.

          This keymap selection affects the interpretation of following
          keystrokes within this invocation of ZLE. Any following
          invocation (e.g., the next command line) will start as usual
          with the ‘main’ keymap selected.

     ‘-F’ [ ‘-L’ | ‘-w’ ] [ FD [ HANDLER ] ]

          Only available if your system supports one of the ‘poll’ or
          ‘select’ system calls; most modern systems do.

          Installs HANDLER (the name of a shell function) to handle
          input from file descriptor FD.  Installing a handler for an FD
          which is already handled causes the existing handler to be
          replaced.  Any number of handlers for any number of readable
          file descriptors may be installed.  Note that zle makes no
          attempt to check whether this FD is actually readable when
          installing the handler.  The user must make their own
          arrangements for handling the file descriptor when zle is not
          active.

          When zle is attempting to read data, it will examine both the
          terminal and the list of handled FD’s.  If data becomes
          available on a handled FD, zle calls HANDLER with the fd which
          is ready for reading as the first argument.  Under normal
          circumstances this is the only argument, but if an error was
          detected, a second argument provides details: ‘hup’ for a
          disconnect, ‘nval’ for a closed or otherwise invalid
          descriptor, or ‘err’ for any other condition.  Systems that
          support only the ‘select’ system call always use ‘err’.

          If the option ‘-w’ is also given, the HANDLER is instead a
          line editor widget, typically a shell function made into a
          widget using ‘zle -N’.  In that case HANDLER can use all the
          facilities of zle to update the current editing line.  Note,
          however, that as handling FD takes place at a low level
          changes to the display will not automatically appear; the
          widget should call ‘zle -R’ to force redisplay.  As of this
          writing, widget handlers only support a single argument and
          thus are never passed a string for error state, so widgets
          must be prepared to test the descriptor themselves.

          If either type of handler produces output to the terminal, it
          should call ‘zle -I’ before doing so (see below).  Handlers
          should not attempt to read from the terminal.

          If no HANDLER is given, but an FD is present, any handler for
          that FD is removed.  If there is none, an error message is
          printed and status 1 is returned.

          If no arguments are given, or the ‘-L’ option is supplied, a
          list of handlers is printed in a form which can be stored for
          later execution.

          An FD (but not a HANDLER) may optionally be given with the
          ‘-L’ option; in this case, the function will list the handler
          if any, else silently return status 1.

          Note that this feature should be used with care.  Activity on
          one of the FD’s which is not properly handled can cause the
          terminal to become unusable.  Removing an FD handler from
          within a signal trap may cause unpredictable behavior.

          Here is a simple example of using this feature.  A connection
          to a remote TCP port is created using the ztcp command; see
          *note The zsh/net/tcp Module: cf.  Then a handler is installed
          which simply prints out any data which arrives on this
          connection.  Note that ‘select’ will indicate that the file
          descriptor needs handling if the remote side has closed the
          connection; we handle that by testing for a failed read.

                if ztcp pwspc 2811; then
                  tcpfd=$REPLY
                  handler() {
                    zle -I
                    local line
                    if ! read -r line <&$1; then
                      # select marks this fd if we reach EOF,
                      # so handle this specially.
                      print "[Read on fd $1 failed, removing.]" >&2
                      zle -F $1
                      return 1
                    fi
                    print -r - $line
                  }
                  zle -F $tcpfd handler
                fi

     ‘-I’

          Unusually, this option is most useful outside ordinary widget
          functions, though it may be used within if normal output to
          the terminal is required.  It invalidates the current zle
          display in preparation for output; typically this will be from
          a trap function.  It has no effect if zle is not active.  When
          a trap exits, the shell checks to see if the display needs
          restoring, hence the following will print output in such a way
          as not to disturb the line being edited:

                TRAPUSR1() {
                  # Invalidate zle display
                  [[ -o zle ]] && zle -I
                  # Show output
                  print Hello
                }

          In general, the trap function may need to test whether zle is
          active before using this method (as shown in the example),
          since the ‘zsh/zle’ module may not even be loaded; if it is
          not, the command can be skipped.

          It is possible to call ‘zle -I’ several times before control
          is returned to the editor; the display will only be
          invalidated the first time to minimise disruption.

          Note that there are normally better ways of manipulating the
          display from within zle widgets; see, for example, ‘zle -R’
          above.

          The returned status is zero if zle was invalidated, even
          though this may have been by a previous call to ‘zle -I’ or by
          a system notification.  To test if a zle widget may be called
          at this point, execute ‘zle’ with no arguments and examine the
          return status.

     ‘-T’

          This is used to add, list or remove internal transformations
          on the processing performed by the line editor.  It is
          typically used only for debugging or testing and is therefore
          of little interest to the general user.

          ‘zle -T’ TRANSFORMATION FUNC specifies that the given
          TRANSFORMATION (see below) is effected by shell function FUNC.

          ‘zle -Tr’ TRANSFORMATION removes the given TRANSFORMATION if
          it was present (it is not an error if none was).

          ‘zle -TL’ can be used to list all transformations currently in
          operation.

          Currently the only transformation is ‘tc’.  This is used
          instead of outputting termcap codes to the terminal.  When the
          transformation is in operation the shell function is passed
          the termcap code that would be output as its first argument;
          if the operation required a numeric argument, that is passed
          as a second argument.  The function should set the shell
          variable ‘REPLY’ to the transformed termcap code.  Typically
          this is used to produce some simply formatted version of the
          code and optional argument for debugging or testing.  Note
          that this transformation is not applied to other non-printing
          characters such as carriage returns and newlines.

     WIDGET [ ‘-n’ NUM ] [ ‘-f’ FLAG ] [ ‘-Nw’ ] [ ‘-K’ KEYMAP ] ARGS …

          Invoke the specified WIDGET.  This can only be done when ZLE
          is active; normally this will be within a user-defined widget.

          With the options ‘-n’ and ‘-N’, the current numeric argument
          will be saved and then restored after the call to WIDGET; ‘-n’
          NUM sets the numeric argument temporarily to NUM, while ‘-N’
          sets it to the default, i.e.  as if there were none.

          With the option ‘-K’, KEYMAP will be used as the current
          keymap during the execution of the widget.  The previous
          keymap will be restored when the widget exits.

          Normally, calling a widget in this way does not set the
          special parameter ‘WIDGET’ and related parameters, so that the
          environment appears as if the top-level widget called by the
          user were still active.  With the option ‘-w’, ‘WIDGET’ and
          related parameters are set to reflect the widget being
          executed by the ‘zle’ call.

          Normally, when WIDGET returns the special parameter
          ‘LASTWIDGET’ will point to it.  This can be inhibited by
          passing the option ‘-f nolast’.

          Any further arguments will be passed to the widget; note that
          as standard argument handling is performed, any general
          argument list should be preceded by ‘--’.  If it is a shell
          function, these are passed down as positional parameters; for
          builtin widgets it is up to the widget in question what it
          does with them.  Currently arguments are only handled by the
          incremental-search commands, the ‘history-search-forward’ and
          ‘-backward’ and the corresponding functions prefixed by ‘vi-’,
          and by ‘universal-argument’.  No error is flagged if the
          command does not use the arguments, or only uses some of them.

          The return status reflects the success or failure of the
          operation carried out by the widget, or if it is a
          user-defined widget the return status of the shell function.

          A non-zero return status causes the shell to beep when the
          widget exits, unless the ‘BEEP’ options was unset or the
          widget was called via the ‘zle’ command.  Thus if a user
          defined widget requires an immediate beep, it should call the
          ‘beep’ widget directly.


File: zsh.info,  Node: Zle Widgets,  Next: User-Defined Widgets,  Prev: Zle Builtins,  Up: Zsh Line Editor

17.4 Zle Widgets
================

All actions in the editor are performed by ‘widgets’.  A widget’s job is
simply to perform some small action.  The ZLE commands that key
sequences in keymaps are bound to are in fact widgets.  Widgets can be
user-defined or built in.

The standard widgets built into ZLE are listed in *note Standard
Widgets: d9.  Other built-in widgets can be defined by other modules
(see ‘zshmodules’).  Each built-in widget has two names: its normal
canonical name, and the same name preceded by a ‘.’.  The ‘.’ name is
special: it can’t be rebound to a different widget.  This makes the
widget available even when its usual name has been redefined.

User-defined widgets are defined using ‘zle -N’, and implemented as
shell functions.  When the widget is executed, the corresponding shell
function is executed, and can perform editing (or other) actions.  It is
recommended that user-defined widgets should not have names starting
with ‘.’.


File: zsh.info,  Node: User-Defined Widgets,  Next: Standard Widgets,  Prev: Zle Widgets,  Up: Zsh Line Editor

17.5 User-Defined Widgets
=========================

User-defined widgets, being implemented as shell functions, can execute
any normal shell command.  They can also run other widgets (whether
built-in or user-defined) using the ‘zle’ builtin command.  The standard
input of the function is redirected from /dev/null to prevent external
commands from unintentionally blocking ZLE by reading from the terminal,
but ‘read -k’ or ‘read -q’ can be used to read characters.  Finally,
they can examine and edit the ZLE buffer being edited by reading and
setting the special parameters described below.

These special parameters are always available in widget functions, but
are not in any way special outside ZLE. If they have some normal value
outside ZLE, that value is temporarily inaccessible, but will return
when the widget function exits.  These special parameters in fact have
local scope, like parameters created in a function using ‘local’.

Inside completion widgets and traps called while ZLE is active, these
parameters are available read-only.

Note that the parameters appear as local to any ZLE widget in which they
appear.  Hence if it is desired to override them this needs to be done
within a nested function:

      widget-function() {
        # $WIDGET here refers to the special variable
        # that is local inside widget-function
        () {
           # This anonymous nested function allows WIDGET
           # to be used as a local variable.  The -h
           # removes the special status of the variable.
           local -h WIDGET
        }
      }

‘BUFFER’ (scalar)

     The entire contents of the edit buffer.  If it is written to, the
     cursor remains at the same offset, unless that would put it outside
     the buffer.

‘BUFFERLINES’ (integer)

     The number of screen lines needed for the edit buffer currently
     displayed on screen (i.e.  without any changes to the preceding
     parameters done after the last redisplay); read-only.

‘CONTEXT’ (scalar)

     The context in which zle was called to read a line; read-only.  One
     of the values:

     ‘start’

          The start of a command line (at prompt ‘PS1’).

     ‘cont’

          A continuation to a command line (at prompt ‘PS2’).

     ‘select’

          In a ‘select’ loop (at prompt ‘PS3’).

     ‘vared’

          Editing a variable in ‘vared’.

‘CURSOR’ (integer)

     The offset of the cursor, within the edit buffer.  This is in the
     range 0 to ‘$#BUFFER’, and is by definition equal to ‘$#LBUFFER’.
     Attempts to move the cursor outside the buffer will result in the
     cursor being moved to the appropriate end of the buffer.

‘CUTBUFFER’ (scalar)

     The last item cut using one of the ‘kill-’ commands; the string
     which the next yank would insert in the line.  Later entries in the
     kill ring are in the array ‘killring’.  Note that the command ‘zle
     copy-region-as-kill’ STRING can be used to set the text of the cut
     buffer from a shell function and cycle the kill ring in the same
     way as interactively killing text.

‘HISTNO’ (integer)

     The current history number.  Setting this has the same effect as
     moving up or down in the history to the corresponding history line.
     An attempt to set it is ignored if the line is not stored in the
     history.  Note this is not the same as the parameter ‘HISTCMD’,
     which always gives the number of the history line being added to
     the main shell’s history.  ‘HISTNO’ refers to the line being
     retrieved within zle.

‘ISEARCHMATCH_ACTIVE’ (integer)

‘ISEARCHMATCH_START’ (integer)

‘ISEARCHMATCH_END’ (integer)

     ‘ISEARCHMATCH_ACTIVE’ indicates whether a part of the ‘BUFFER’ is
     currently matched by an incremental search pattern.
     ‘ISEARCHMATCH_START’ and ‘ISEARCHMATCH_END’ give the location of
     the matched part and are in the same units as ‘CURSOR’.  They are
     only valid for reading when ‘ISEARCHMATCH_ACTIVE’ is non-zero.

     All parameters are read-only.

‘KEYMAP’ (scalar)

     The name of the currently selected keymap; read-only.

‘KEYS’ (scalar)

     The keys typed to invoke this widget, as a literal string;
     read-only.

‘KEYS_QUEUED_COUNT’ (integer)

     The number of bytes pushed back to the input queue and therefore
     available for reading immediately before any I/O is done;
     read-only.  See also ‘PENDING’; the two values are distinct.

‘killring’ (array)

     The array of previously killed items, with the most recently killed
     first.  This gives the items that would be retrieved by a
     ‘yank-pop’ in the same order.  Note, however, that the most
     recently killed item is in ‘$CUTBUFFER’; ‘$killring’ shows the
     array of previous entries.

     The default size for the kill ring is eight, however the length may
     be changed by normal array operations.  Any empty string in the
     kill ring is ignored by the ‘yank-pop’ command, hence the size of
     the array effectively sets the maximum length of the kill ring,
     while the number of non-zero strings gives the current length, both
     as seen by the user at the command line.

‘LASTABORTEDSEARCH’ (scalar)

     The last search string used by an interactive search that was
     aborted by the user (status 3 returned by the search widget).

‘LASTSEARCH’ (scalar)

     The last search string used by an interactive search; read-only.
     This is set even if the search failed (status 0, 1 or 2 returned by
     the search widget), but not if it was aborted by the user.

‘LASTWIDGET’ (scalar)

     The name of the last widget that was executed; read-only.

‘LBUFFER’ (scalar)

     The part of the buffer that lies to the left of the cursor
     position.  If it is assigned to, only that part of the buffer is
     replaced, and the cursor remains between the new ‘$LBUFFER’ and the
     old ‘$RBUFFER’.

‘MARK’ (integer)

     Like ‘CURSOR’, but for the mark.  With vi-mode operators that wait
     for a movement command to select a region of text, setting ‘MARK’
     allows the selection to extend in both directions from the initial
     cursor position.

‘NUMERIC’ (integer)

     The numeric argument.  If no numeric argument was given, this
     parameter is unset.  When this is set inside a widget function,
     builtin widgets called with the ‘zle’ builtin command will use the
     value assigned.  If it is unset inside a widget function, builtin
     widgets called behave as if no numeric argument was given.

‘PENDING’ (integer)

     The number of bytes pending for input, i.e.  the number of bytes
     which have already been typed and can immediately be read.  On
     systems where the shell is not able to get this information, this
     parameter will always have a value of zero.  Read-only.  See also
     ‘KEYS_QUEUED_COUNT’; the two values are distinct.

‘PREBUFFER’ (scalar)

     In a multi-line input at the secondary prompt, this read-only
     parameter contains the contents of the lines before the one the
     cursor is currently in.

‘PREDISPLAY’ (scalar)

     Text to be displayed before the start of the editable text buffer.
     This does not have to be a complete line; to display a complete
     line, a newline must be appended explicitly.  The text is reset on
     each new invocation (but not recursive invocation) of zle.

‘POSTDISPLAY’ (scalar)

     Text to be displayed after the end of the editable text buffer.
     This does not have to be a complete line; to display a complete
     line, a newline must be prepended explicitly.  The text is reset on
     each new invocation (but not recursive invocation) of zle.

‘RBUFFER’ (scalar)

     The part of the buffer that lies to the right of the cursor
     position.  If it is assigned to, only that part of the buffer is
     replaced, and the cursor remains between the old ‘$LBUFFER’ and the
     new ‘$RBUFFER’.

‘REGION_ACTIVE’ (integer)

     Indicates if the region is currently active.  It can be assigned 0
     or 1 to deactivate and activate the region respectively.  A value
     of 2 activates the region in line-wise mode with the highlighted
     text extending for whole lines only; see *note Character
     Highlighting: 60.

‘region_highlight’ (array)

     Each element of this array may be set to a string that describes
     highlighting for an arbitrary region of the command line that will
     take effect the next time the command line is redisplayed.
     Highlighting of the non-editable parts of the command line in
     ‘PREDISPLAY’ and ‘POSTDISPLAY’ are possible, but note that the ‘P’
     flag is needed for character indexing to include ‘PREDISPLAY’.

     Each string consists of the following whitespace-separated parts:

             * Optionally, a ‘P’ to signify that the start and end
               offset that

          follow include any string set by the ‘PREDISPLAY’ special
          parameter; this is needed if the predisplay string itself is
          to be highlighted.  Whitespace between the ‘P’ and the start
          offset is optional.  * A start offset in the same units as
          ‘CURSOR’.  * An end offset in the same units as ‘CURSOR’.  * A
          highlight specification in the same format as used for
          contexts in the parameter ‘zle_highlight’, see *note Character
          Highlighting: 60.; for example, ‘standout’ or ‘fg=red,bold’.
          * Optionally, a string of the form ‘memo=’TOKEN.  The TOKEN
          consists of everything between the ‘=’ and the next
          whitespace, comma, NUL, or the end of the string.  The TOKEN
          is preserved verbatim but not parsed in any way.

          Plugins may use this to identify array elements they have
          added: for example, a plugin might set TOKEN to its (the
          plugin’s) name and then use ‘region_highlight=(
          ${region_highlight:#*memo=’TOKEN‘} )’ in order to remove array
          elements it added.

          (This example uses the ‘${’NAME‘:#’PATTERN‘}’ array-grepping
          syntax described in *note Parameter Expansion: 1a.)

     For example,

           region_highlight=("P0 20 bold memo=foobar")

     specifies that the first twenty characters of the text including
     any predisplay string should be highlighted in bold.

     Note that the effect of ‘region_highlight’ is not saved and
     disappears as soon as the line is accepted.

     Note that zsh 5.8 and older do not support the ‘memo=’TOKEN field
     and may misparse the third (highlight specification) field when a
     memo is given.

     Where a particular region is covered by multiple entries in
     ‘region_highlight’, their effects are merged.  In the case of
     conflicts, later entries take precedence over earlier ones.  This
     precedence ordering can be overridden by specifying layers.

     The final highlighting on the command line depends on both
     ‘region_highlight’ and ‘zle_highlight’; see *note Character
     Highlighting: 60. for details.

‘registers’ (associative array)

     The contents of each of the vi register buffers.  These are
     typically set using ‘vi-set-buffer’ followed by a delete, change or
     yank command.

‘SUFFIX_ACTIVE’ (integer)

‘SUFFIX_START’ (integer)

‘SUFFIX_END’ (integer)

     ‘SUFFIX_ACTIVE’ indicates whether an auto-removable completion
     suffix is currently active.  ‘SUFFIX_START’ and ‘SUFFIX_END’ give
     the location of the suffix and are in the same units as ‘CURSOR’.
     They are only valid for reading when ‘SUFFIX_ACTIVE’ is non-zero.

     All parameters are read-only.

‘UNDO_CHANGE_NO’ (integer)

     A number representing the state of the undo history.  The only use
     of this is passing as an argument to the ‘undo’ widget in order to
     undo back to the recorded point.  Read-only.

‘UNDO_LIMIT_NO’ (integer)

     A number corresponding to an existing change in the undo history;
     compare ‘UNDO_CHANGE_NO’.  If this is set to a value greater than
     zero, the ‘undo’ command will not allow the line to be undone
     beyond the given change number.  It is still possible to use ‘zle
     undo’ CHANGE in a widget to undo beyond that point; in that case,
     it will not be possible to undo at all until ‘UNDO_LIMIT_NO’ is
     reduced.  Set to 0 to disable the limit.

     A typical use of this variable in a widget function is as follows
     (note the additional function scope is required):

           () {
             local UNDO_LIMIT_NO=$UNDO_CHANGE_NO
             # Perform some form of recursive edit.
           }

‘WIDGET’ (scalar)

     The name of the widget currently being executed; read-only.

‘WIDGETFUNC’ (scalar)

     The name of the shell function that implements a widget defined
     with either ‘zle -N’ or ‘zle -C’.  In the former case, this is the
     second argument to the ‘zle -N’ command that defined the widget, or
     the first argument if there was no second argument.  In the latter
     case this is the third argument to the ‘zle -C’ command that
     defined the widget.  Read-only.

‘WIDGETSTYLE’ (scalar)

     Describes the implementation behind the completion widget currently
     being executed; the second argument that followed ‘zle -C’ when the
     widget was defined.  This is the name of a builtin completion
     widget.  For widgets defined with ‘zle -N’ this is set to the empty
     string.  Read-only.

‘YANK_ACTIVE’ (integer)

‘YANK_START’ (integer)

‘YANK_END’ (integer)

     ‘YANK_ACTIVE’ indicates whether text has just been yanked (pasted)
     into the buffer.  ‘YANK_START’ and ‘YANK_END’ give the location of
     the pasted text and are in the same units as ‘CURSOR’.  They are
     only valid for reading when ‘YANK_ACTIVE’ is non-zero.  They can
     also be assigned by widgets that insert text in a yank-like
     fashion, for example wrappers of ‘bracketed-paste’.  See also ‘zle
     -f’.

     ‘YANK_ACTIVE’ is read-only.

‘ZLE_RECURSIVE’ (integer)

     Usually zero, but incremented inside any instance of
     ‘recursive-edit’.  Hence indicates the current recursion level.

     ‘ZLE_RECURSIVE’ is read-only.

‘ZLE_STATE’ (scalar)

     Contains a set of space-separated words that describe the current
     ‘zle’ state.

     Currently, the states shown are the insert mode as set by the
     ‘overwrite-mode’ or ‘vi-replace’ widgets and whether history
     commands will visit imported entries as controlled by the
     set-local-history widget.  The string contains ‘insert’ if
     characters to be inserted on the command line move existing
     characters to the right or ‘overwrite’ if characters to be inserted
     overwrite existing characters.  It contains ‘localhistory’ if only
     local history commands will be visited or ‘globalhistory’ if
     imported history commands will also be visited.

     The substrings are sorted in alphabetical order so that if you want
     to test for two specific substrings in a future-proof way, you can
     do match by doing:

           if [[ $ZLE_STATE == *globalhistory*insert* ]]; then ...; fi

* Menu:

* Special Widgets::


File: zsh.info,  Node: Special Widgets,  Up: User-Defined Widgets

17.5.1 Special Widgets
----------------------

There are a few user-defined widgets which are special to the shell.  If
they do not exist, no special action is taken.  The environment provided
is identical to that for any other editing widget.

‘zle-isearch-exit’

     Executed at the end of incremental search at the point where the
     isearch prompt is removed from the display.  See
     ‘zle-isearch-update’ for an example.

‘zle-isearch-update’

     Executed within incremental search when the display is about to be
     redrawn.  Additional output below the incremental search prompt can
     be generated by using ‘zle -M’ within the widget.  For example,

           zle-isearch-update() { zle -M "Line $HISTNO"; }
           zle -N zle-isearch-update

     Note the line output by ‘zle -M’ is not deleted on exit from
     incremental search.  This can be done from a ‘zle-isearch-exit’
     widget:

           zle-isearch-exit() { zle -M ""; }
           zle -N zle-isearch-exit

‘zle-line-pre-redraw’

     Executed whenever the input line is about to be redrawn, providing
     an opportunity to update the region_highlight array.

‘zle-line-init’

     Executed every time the line editor is started to read a new line
     of input.  The following example puts the line editor into vi
     command mode when it starts up.

           zle-line-init() { zle -K vicmd; }
           zle -N zle-line-init

     (The command inside the function sets the keymap directly; it is
     equivalent to ‘zle vi-cmd-mode’.)

‘zle-line-finish’

     This is similar to ‘zle-line-init’ but is executed every time the
     line editor has finished reading a line of input.

‘zle-history-line-set’

     Executed when the history line changes.

‘zle-keymap-select’

     Executed every time the keymap changes, i.e.  the special parameter
     ‘KEYMAP’ is set to a different value, while the line editor is
     active.  Initialising the keymap when the line editor starts does
     not cause the widget to be called.

     The value ‘$KEYMAP’ within the function reflects the new keymap.
     The old keymap is passed as the sole argument.

     This can be used for detecting switches between the vi command
     (‘vicmd’) and insert (usually ‘main’) keymaps.


File: zsh.info,  Node: Standard Widgets,  Next: Terminal Extensions,  Prev: User-Defined Widgets,  Up: Zsh Line Editor

17.6 Standard Widgets
=====================

The following is a list of all the standard widgets, and their default
bindings in emacs mode, vi command mode and vi insert mode (the ‘emacs’,
‘vicmd’ and ‘viins’ keymaps, respectively).

Note that cursor keys are bound to movement keys in all three keymaps;
the shell assumes that the cursor keys send the key sequences reported
by the terminal-handling library (termcap or terminfo).  The key
sequences shown in the list are those based on the VT100, common on many
modern terminals, but in fact these are not necessarily bound.  In the
case of the ‘viins’ keymap, the initial escape character of the
sequences serves also to return to the ‘vicmd’ keymap: whether this
happens is determined by the ‘KEYTIMEOUT’ parameter, see *note
Parameters Used by the Shell: 11.

* Menu:

* Movement::
* History Control::
* Modifying Text::
* Arguments::
* Completion: Completion<3>.
* Miscellaneous::
* Text Objects::


File: zsh.info,  Node: Movement,  Next: History Control,  Up: Standard Widgets

17.6.1 Movement
---------------

‘vi-backward-blank-word’ (unbound) (‘B’) (unbound)

     Move backward one word, where a word is defined as a series of
     non-blank characters.

‘vi-backward-blank-word-end’ (unbound) (‘gE’) (unbound)

     Move to the end of the previous word, where a word is defined as a
     series of non-blank characters.

‘backward-char’ (‘^B ESC-[D’) (unbound) (unbound)

     Move backward one character.

‘vi-backward-char’ (unbound) (‘^H h ^?’) (‘ESC-[D’)

     Move backward one character, without changing lines.

‘backward-word’ (‘ESC-B ESC-b’) (unbound) (unbound)

     Move to the beginning of the previous word.

‘emacs-backward-word’

     Move to the beginning of the previous word.

‘vi-backward-word’ (unbound) (‘b’) (unbound)

     Move to the beginning of the previous word, vi-style.

‘vi-backward-word-end’ (unbound) (‘ge’) (unbound)

     Move to the end of the previous word, vi-style.

‘beginning-of-line’ (‘^A’) (unbound) (unbound)

     Move to the beginning of the line.  If already at the beginning of
     the line, move to the beginning of the previous line, if any.

‘vi-beginning-of-line’

     Move to the beginning of the line, without changing lines.

‘down-line’ (unbound) (unbound) (unbound)

     Move down a line in the buffer.

‘end-of-line’ (‘^E’) (unbound) (unbound)

     Move to the end of the line.  If already at the end of the line,
     move to the end of the next line, if any.

‘vi-end-of-line’ (unbound) (‘$’) (unbound)

     Move to the end of the line.  If an argument is given to this
     command, the cursor will be moved to the end of the line (argument
     - 1) lines down.

‘vi-forward-blank-word’ (unbound) (‘W’) (unbound)

     Move forward one word, where a word is defined as a series of
     non-blank characters.

‘vi-forward-blank-word-end’ (unbound) (‘E’) (unbound)

     Move to the end of the current word, or, if at the end of the
     current word, to the end of the next word, where a word is defined
     as a series of non-blank characters.

‘forward-char’ (‘^F ESC-[C’) (unbound) (unbound)

     Move forward one character.

‘vi-forward-char’ (unbound) (‘space l’) (‘ESC-[C’)

     Move forward one character.

‘vi-find-next-char’ (‘^X^F’) (‘f’) (unbound)

     Read a character from the keyboard, and move to the next occurrence
     of it in the line.

‘vi-find-next-char-skip’ (unbound) (‘t’) (unbound)

     Read a character from the keyboard, and move to the position just
     before the next occurrence of it in the line.

‘vi-find-prev-char’ (unbound) (‘F’) (unbound)

     Read a character from the keyboard, and move to the previous
     occurrence of it in the line.

‘vi-find-prev-char-skip’ (unbound) (‘T’) (unbound)

     Read a character from the keyboard, and move to the position just
     after the previous occurrence of it in the line.

‘vi-first-non-blank’ (unbound) (‘_ ^’) (unbound)

     Move to the first non-blank character in the line.

‘vi-forward-word’ (unbound) (‘w’) (unbound)

     Move forward one word, vi-style.

‘forward-word’ (‘ESC-F ESC-f’) (unbound) (unbound)

     Move to the beginning of the next word.  The editor’s idea of a
     word is specified with the ‘WORDCHARS’ parameter.

‘emacs-forward-word’

     Move to the end of the next word.

‘vi-forward-word-end’ (unbound) (‘e’) (unbound)

     Move to the end of the next word.

‘vi-goto-column’ (‘ESC-|’) (‘|’) (unbound)

     Move to the column specified by the numeric argument.

‘vi-goto-mark’ (unbound) (>>‘‘<<>>‘‘<<) (unbound)

     Move to the specified mark.

‘vi-goto-mark-line’ (unbound) (>>‘‘<<>>‘‘<<) (unbound)

     Move to beginning of the line containing the specified mark.

‘vi-repeat-find’ (unbound) (‘;’) (unbound)

     Repeat the last ‘vi-find’ command.

‘vi-rev-repeat-find’ (unbound) (‘,’) (unbound)

     Repeat the last ‘vi-find’ command in the opposite direction.

‘up-line’ (unbound) (unbound) (unbound)

     Move up a line in the buffer.


File: zsh.info,  Node: History Control,  Next: Modifying Text,  Prev: Movement,  Up: Standard Widgets

17.6.2 History Control
----------------------

‘beginning-of-buffer-or-history’ (‘ESC-<’) (‘gg’) (unbound)

     Move to the beginning of the buffer, or if already there, move to
     the first event in the history list.

‘beginning-of-line-hist’

     Move to the beginning of the line.  If already at the beginning of
     the buffer, move to the previous history line.

‘beginning-of-history’

     Move to the first event in the history list.

‘down-line-or-history’ (‘^N ESC-[B’) (‘j’) (‘ESC-[B’)

     Move down a line in the buffer, or if already at the bottom line,
     move to the next event in the history list.

‘vi-down-line-or-history’ (unbound) (‘+’) (unbound)

     Move down a line in the buffer, or if already at the bottom line,
     move to the next event in the history list.  Then move to the first
     non-blank character on the line.

‘down-line-or-search’

     Move down a line in the buffer, or if already at the bottom line,
     search forward in the history for a line beginning with the first
     word in the buffer.

     If called from a function by the ‘zle’ command with arguments, the
     first argument is taken as the string for which to search, rather
     than the first word in the buffer.

‘down-history’ (unbound) (‘^N’) (unbound)

     Move to the next event in the history list.

‘history-beginning-search-backward’

     Search backward in the history for a line beginning with the
     current line up to the cursor.  This leaves the cursor in its
     original position.

‘end-of-buffer-or-history’ (‘ESC->’) (unbound) (unbound)

     Move to the end of the buffer, or if already there, move to the
     last event in the history list.

‘end-of-line-hist’

     Move to the end of the line.  If already at the end of the buffer,
     move to the next history line.

‘end-of-history’

     Move to the last event in the history list.

‘vi-fetch-history’ (unbound) (‘G’) (unbound)

     Fetch the history line specified by the numeric argument.  This
     defaults to the current history line (i.e.  the one that isn’t
     history yet).

‘history-incremental-search-backward’ (‘^R ^Xr’) (unbound) (unbound)

     Search backward incrementally for a specified string.  The search
     is case-insensitive if the search string does not have uppercase
     letters and no numeric argument was given.  The string may begin
     with ‘^’ to anchor the search to the beginning of the line.  When
     called from a user-defined function returns the following statuses:
     0, if the search succeeded; 1, if the search failed; 2, if the
     search term was a bad pattern; 3, if the search was aborted by the
     ‘send-break’ command.

     A restricted set of editing functions is available in the
     mini-buffer.  Keys are looked up in the special ‘isearch’ keymap,
     and if not found there in the main keymap (note that by default the
     ‘isearch’ keymap is empty).  An interrupt signal, as defined by the
     stty setting, will stop the search and go back to the original
     line.  An undefined key will have the same effect.  Note that the
     following always perform the same task within incremental searches
     and cannot be replaced by user defined widgets, nor can the set of
     functions be extended.  The supported functions are:

     ‘accept-and-hold’

     ‘accept-and-infer-next-history’

     ‘accept-line’

     ‘accept-line-and-down-history’

          Perform the usual function after exiting incremental search.
          The command line displayed is executed.

     ‘backward-delete-char’

     ‘vi-backward-delete-char’

          Back up one place in the search history.  If the search has
          been repeated this does not immediately erase a character in
          the minibuffer.

     ‘accept-search’

          Exit incremental search, retaining the command line but
          performing no further action.  Note that this function is not
          bound by default and has no effect outside incremental search.

     ‘backward-delete-word’

     ‘backward-kill-word’

     ‘vi-backward-kill-word’

          Back up one character in the minibuffer; if multiple searches
          have been performed since the character was inserted the
          search history is rewound to the point just before the
          character was entered.  Hence this has the effect of repeating
          ‘backward-delete-char’.

     ‘clear-screen’

          Clear the screen, remaining in incremental search mode.

     ‘history-incremental-search-backward’

          Find the next occurrence of the contents of the mini-buffer.
          If the mini-buffer is empty, the most recent previously used
          search string is reinstated.

     ‘history-incremental-search-forward’

          Invert the sense of the search.

     ‘magic-space’

          Inserts a non-magical space.

     ‘quoted-insert’

     ‘vi-quoted-insert’

          Quote the character to insert into the minibuffer.

     ‘redisplay’

          Redisplay the command line, remaining in incremental search
          mode.

     ‘vi-cmd-mode’

          Select the ‘vicmd’ keymap; the ‘main’ keymap (insert mode)
          will be selected initially.

          In addition, the modifications that were made while in vi
          insert mode are merged to form a single undo event.

     ‘vi-repeat-search’

     ‘vi-rev-repeat-search’

          Repeat the search.  The direction of the search is indicated
          in the mini-buffer.

     Any character that is not bound to one of the above functions, or
     ‘self-insert’ or ‘self-insert-unmeta’, will cause the mode to be
     exited.  The character is then looked up and executed in the keymap
     in effect at that point.

     When called from a widget function by the ‘zle’ command, the
     incremental search commands can take a string argument.  This will
     be treated as a string of keys, as for arguments to the ‘bindkey’
     command, and used as initial input for the command.  Any characters
     in the string which are unused by the incremental search will be
     silently ignored.  For example,

           zle history-incremental-search-backward forceps

     will search backwards for ‘forceps’, leaving the minibuffer
     containing the string ‘forceps’.

‘history-incremental-search-forward’ (‘^S ^Xs’) (unbound) (unbound)

     Search forward incrementally for a specified string.  The search is
     case-insensitive if the search string does not have uppercase
     letters and no numeric argument was given.  The string may begin
     with ‘^’ to anchor the search to the beginning of the line.  The
     functions available in the mini-buffer are the same as for
     ‘history-incremental-search-backward’.

‘history-incremental-pattern-search-backward’

‘history-incremental-pattern-search-forward’

     These widgets behave similarly to the corresponding widgets with no
     ‘-pattern’, but the search string typed by the user is treated as a
     pattern, respecting the current settings of the various options
     affecting pattern matching.  See *note Filename Generation: 17. for
     a description of patterns.  If no numeric argument was given
     lowercase letters in the search string may match uppercase letters
     in the history.  The string may begin with ‘^’ to anchor the search
     to the beginning of the line.

     The prompt changes to indicate an invalid pattern; this may simply
     indicate the pattern is not yet complete.

     Note that only non-overlapping matches are reported, so an
     expression with wildcards may return fewer matches on a line than
     are visible by inspection.

‘history-search-backward’ (‘ESC-P ESC-p’) (unbound) (unbound)

     Search backward in the history for a line beginning with the first
     word in the buffer.

     If called from a function by the ‘zle’ command with arguments, the
     first argument is taken as the string for which to search, rather
     than the first word in the buffer.

‘vi-history-search-backward’ (unbound) (‘/’) (unbound)

     Search backward in the history for a specified string.  The string
     may begin with ‘^’ to anchor the search to the beginning of the
     line.

     A restricted set of editing functions is available in the
     mini-buffer.  An interrupt signal, as defined by the stty setting,
     will stop the search.  The functions available in the mini-buffer
     are: ‘accept-line’, ‘backward-delete-char’,
     ‘vi-backward-delete-char’, ‘backward-kill-word’,
     ‘vi-backward-kill-word’, ‘clear-screen’, ‘redisplay’,
     ‘quoted-insert’ and ‘vi-quoted-insert’.

     ‘vi-cmd-mode’ is treated the same as accept-line, and ‘magic-space’
     is treated as a space.  Any other character that is not bound to
     self-insert or self-insert-unmeta will beep and be ignored.  If the
     function is called from vi command mode, the bindings of the
     current insert mode will be used.

     If called from a function by the ‘zle’ command with arguments, the
     first argument is taken as the string for which to search, rather
     than the first word in the buffer.

‘history-search-forward’ (‘ESC-N ESC-n’) (unbound) (unbound)

     Search forward in the history for a line beginning with the first
     word in the buffer.

     If called from a function by the ‘zle’ command with arguments, the
     first argument is taken as the string for which to search, rather
     than the first word in the buffer.

‘vi-history-search-forward’ (unbound) (‘?’) (unbound)

     Search forward in the history for a specified string.  The string
     may begin with ‘^’ to anchor the search to the beginning of the
     line.  The functions available in the mini-buffer are the same as
     for ‘vi-history-search-backward’.  Argument handling is also the
     same as for that command.

‘infer-next-history’ (‘^X^N’) (unbound) (unbound)

     Search in the history list for a line matching the current one and
     fetch the event following it.

‘insert-last-word’ (‘ESC-_ ESC-.’) (unbound) (unbound)

     Insert the last word from the previous history event at the cursor
     position.  If a positive numeric argument is given, insert that
     word from the end of the previous history event.  If the argument
     is zero or negative insert that word from the left (zero inserts
     the previous command word).  Repeating this command replaces the
     word just inserted with the last word from the history event prior
     to the one just used; numeric arguments can be used in the same way
     to pick a word from that event.

     When called from a shell function invoked from a user-defined
     widget, the command can take one to three arguments.  The first
     argument specifies a history offset which applies to successive
     calls to this widget: if it is -1, the default behaviour is used,
     while if it is 1, successive calls will move forwards through the
     history.  The value 0 can be used to indicate that the history line
     examined by the previous execution of the command will be
     reexamined.  Note that negative numbers should be preceded by a
     ‘--’ argument to avoid confusing them with options.

     If two arguments are given, the second specifies the word on the
     command line in normal array index notation (as a more natural
     alternative to the numeric argument).  Hence 1 is the first word,
     and -1 (the default) is the last word.

     If a third argument is given, its value is ignored, but it is used
     to signify that the history offset is relative to the current
     history line, rather than the one remembered after the previous
     invocations of ‘insert-last-word’.

     For example, the default behaviour of the command corresponds to

           zle insert-last-word -- -1 -1

     while the command

           zle insert-last-word -- -1 1 -

     always copies the first word of the line in the history immediately
     before the line being edited.  This has the side effect that later
     invocations of the widget will be relative to that line.

‘vi-repeat-search’ (unbound) (‘n’) (unbound)

     Repeat the last vi history search.

‘vi-rev-repeat-search’ (unbound) (‘N’) (unbound)

     Repeat the last vi history search, but in reverse.

‘up-line-or-history’ (‘^P ESC-[A’) (‘k’) (‘ESC-[A’)

     Move up a line in the buffer, or if already at the top line, move
     to the previous event in the history list.

‘vi-up-line-or-history’ (unbound) (‘-’) (unbound)

     Move up a line in the buffer, or if already at the top line, move
     to the previous event in the history list.  Then move to the first
     non-blank character on the line.

‘up-line-or-search’

     Move up a line in the buffer, or if already at the top line, search
     backward in the history for a line beginning with the first word in
     the buffer.

     If called from a function by the ‘zle’ command with arguments, the
     first argument is taken as the string for which to search, rather
     than the first word in the buffer.

‘up-history’ (unbound) (‘^P’) (unbound)

     Move to the previous event in the history list.

‘history-beginning-search-forward’

     Search forward in the history for a line beginning with the current
     line up to the cursor.  This leaves the cursor in its original
     position.

‘set-local-history’

     By default, history movement commands visit the imported lines as
     well as the local lines.  This widget lets you toggle this on and
     off, or set it with the numeric argument.  Zero for both local and
     imported lines and nonzero for only local lines.


File: zsh.info,  Node: Modifying Text,  Next: Arguments,  Prev: History Control,  Up: Standard Widgets

17.6.3 Modifying Text
---------------------

‘vi-add-eol’ (unbound) (‘A’) (unbound)

     Move to the end of the line and enter insert mode.

‘vi-add-next’ (unbound) (‘a’) (unbound)

     Enter insert mode after the current cursor position, without
     changing lines.

‘backward-delete-char’ (‘^H ^?’) (unbound) (unbound)

     Delete the character behind the cursor.

‘vi-backward-delete-char’ (unbound) (‘X’) (‘^H’)

     Delete the character behind the cursor, without changing lines.  If
     in insert mode, this won’t delete past the point where insert mode
     was last entered.

‘backward-delete-word’

     Delete the word behind the cursor.

‘backward-kill-line’

     Kill from the beginning of the line to the cursor position.

‘backward-kill-word’ (‘^W ESC-^H ESC-^?’) (unbound) (unbound)

     Kill the word behind the cursor.

‘vi-backward-kill-word’ (unbound) (unbound) (‘^W’)

     Kill the word behind the cursor, without going past the point where
     insert mode was last entered.

‘capitalize-word’ (‘ESC-C ESC-c’) (unbound) (unbound)

     Capitalize the current word and move past it.

‘vi-change’ (unbound) (‘c’) (unbound)

     Read a movement command from the keyboard, and kill from the cursor
     position to the endpoint of the movement.  Then enter insert mode.
     If the command is ‘vi-change’, change the current line.

     For compatibility with vi, if the command is ‘vi-forward-word’ or
     ‘vi-forward-blank-word’, the whitespace after the word is not
     included.  If you prefer the more consistent behaviour with the
     whitespace included use the following key binding:

           bindkey -a -s cw dwi

‘vi-change-eol’ (unbound) (‘C’) (unbound)

     Kill to the end of the line and enter insert mode.

‘vi-change-whole-line’ (unbound) (‘S’) (unbound)

     Kill the current line and enter insert mode.

‘copy-region-as-kill’ (‘ESC-W ESC-w’) (unbound) (unbound)

     Copy the area from the cursor to the mark to the kill buffer.

     If called from a ZLE widget function in the form ‘zle
     copy-region-as-kill’ STRING then STRING will be taken as the text
     to copy to the kill buffer.  The cursor, the mark and the text on
     the command line are not used in this case.

‘copy-prev-word’ (‘ESC-^_’) (unbound) (unbound)

     Duplicate the word to the left of the cursor.

‘copy-prev-shell-word’

     Like ‘copy-prev-word’, but the word is found by using shell
     parsing, whereas ‘copy-prev-word’ looks for blanks.  This makes a
     difference when the word is quoted and contains spaces.

‘vi-delete’ (unbound) (‘d’) (unbound)

     Read a movement command from the keyboard, and kill from the cursor
     position to the endpoint of the movement.  If the command is
     ‘vi-delete’, kill the current line.

‘delete-char’

     Delete the character under the cursor.

‘vi-delete-char’ (unbound) (‘x’) (unbound)

     Delete the character under the cursor, without going past the end
     of the line.

‘delete-word’

     Delete the current word.

‘down-case-word’ (‘ESC-L ESC-l’) (unbound) (unbound)

     Convert the current word to all lowercase and move past it.

‘vi-down-case’ (unbound) (‘gu’) (unbound)

     Read a movement command from the keyboard, and convert all
     characters from the cursor position to the endpoint of the movement
     to lowercase.  If the movement command is ‘vi-down-case’, swap the
     case of all characters on the current line.

‘kill-word’ (‘ESC-D ESC-d’) (unbound) (unbound)

     Kill the current word.

‘gosmacs-transpose-chars’

     Exchange the two characters behind the cursor.

‘vi-indent’ (unbound) (‘>’) (unbound)

     Indent a number of lines.

‘vi-insert’ (unbound) (‘i’) (unbound)

     Enter insert mode.

‘vi-insert-bol’ (unbound) (‘I’) (unbound)

     Move to the first non-blank character on the line and enter insert
     mode.

‘vi-join’ (‘^X^J’) (‘J’) (unbound)

     Join the current line with the next one.

‘kill-line’ (‘^K’) (unbound) (unbound)

     Kill from the cursor to the end of the line.  If already on the end
     of the line, kill the newline character.

‘vi-kill-line’ (unbound) (unbound) (‘^U’)

     Kill from the cursor back to wherever insert mode was last entered.

‘vi-kill-eol’ (unbound) (‘D’) (unbound)

     Kill from the cursor to the end of the line.

‘kill-region’

     Kill from the cursor to the mark.

‘kill-buffer’ (‘^X^K’) (unbound) (unbound)

     Kill the entire buffer.

‘kill-whole-line’ (‘^U’) (unbound) (unbound)

     Kill the current line.

‘vi-match-bracket’ (‘^X^B’) (‘%’) (unbound)

     Move to the bracket character (one of ‘{}’, ‘()’ or ‘[]’) that
     matches the one under the cursor.  If the cursor is not on a
     bracket character, move forward without going past the end of the
     line to find one, and then go to the matching bracket.

‘vi-open-line-above’ (unbound) (‘O’) (unbound)

     Open a line above the cursor and enter insert mode.

‘vi-open-line-below’ (unbound) (‘o’) (unbound)

     Open a line below the cursor and enter insert mode.

‘vi-oper-swap-case’ (unbound) (‘g~’) (unbound)

     Read a movement command from the keyboard, and swap the case of all
     characters from the cursor position to the endpoint of the
     movement.  If the movement command is ‘vi-oper-swap-case’, swap the
     case of all characters on the current line.

‘overwrite-mode’ (‘^X^O’) (unbound) (unbound)

     Toggle between overwrite mode and insert mode.

‘vi-put-before’ (unbound) (‘P’) (unbound)

     Insert the contents of the kill buffer before the cursor.  If the
     kill buffer contains a sequence of lines (as opposed to
     characters), paste it above the current line.

‘vi-put-after’ (unbound) (‘p’) (unbound)

     Insert the contents of the kill buffer after the cursor.  If the
     kill buffer contains a sequence of lines (as opposed to
     characters), paste it below the current line.

‘put-replace-selection’ (unbound) (unbound) (unbound)

     Replace the contents of the current region or selection with the
     contents of the kill buffer.  If the kill buffer contains a
     sequence of lines (as opposed to characters), the current line will
     be split by the pasted lines.

‘quoted-insert’ (‘^V’) (unbound) (unbound)

     Insert the next character typed into the buffer literally.  An
     interrupt character will not be inserted.

‘vi-quoted-insert’ (unbound) (unbound) (‘^Q ^V’)

     Display a ‘^’ at the cursor position, and insert the next character
     typed into the buffer literally.  An interrupt character will not
     be inserted.

‘quote-line’ (‘ESC-'’) (unbound) (unbound)

     Quote the current line; that is, put a >>‘‘<<‘' character at the
     beginning and the end, and convert all ``’’ characters to ‘\''’’.

‘quote-region’ (‘ESC-"’) (unbound) (unbound)

     Quote the region from the cursor to the mark.

‘vi-replace’ (unbound) (‘R’) (unbound)

     Enter overwrite mode.

‘vi-repeat-change’ (unbound) (‘.’) (unbound)

     Repeat the last vi mode text modification.  If a count was used
     with the modification, it is remembered.  If a count is given to
     this command, it overrides the remembered count, and is remembered
     for future uses of this command.  The cut buffer specification is
     similarly remembered.

‘vi-replace-chars’ (unbound) (‘r’) (unbound)

     Replace the character under the cursor with a character read from
     the keyboard.

‘self-insert’ (printable characters) (unbound) (printable characters and
some control characters)

     Insert a character into the buffer at the cursor position.

‘self-insert-unmeta’ (‘ESC-^I ESC-^J ESC-^M’) (unbound) (unbound)

     Insert a character into the buffer after stripping the meta bit and
     converting ^M to ^J.

‘vi-substitute’ (unbound) (‘s’) (unbound)

     Substitute the next character(s).

‘vi-swap-case’ (unbound) (‘~’) (unbound)

     Swap the case of the character under the cursor and move past it.

‘transpose-chars’ (‘^T’) (unbound) (unbound)

     Exchange the two characters to the left of the cursor if at end of
     line, else exchange the character under the cursor with the
     character to the left.

‘transpose-words’ (‘ESC-T ESC-t’) (unbound) (unbound)

     Exchange the current word with the one before it.

     With a positive numeric argument ‘N’, the word around the cursor,
     or following it if the cursor is between words, is transposed with
     the preceding ‘N’ words.  The cursor is put at the end of the
     resulting group of words.

     With a negative numeric argument ‘-N’, the effect is the same as
     using a positive argument ‘N’ except that the original cursor
     position is retained, regardless of how the words are rearranged.

‘vi-unindent’ (unbound) (‘<’) (unbound)

     Unindent a number of lines.

‘vi-up-case’ (unbound) (‘gU’) (unbound)

     Read a movement command from the keyboard, and convert all
     characters from the cursor position to the endpoint of the movement
     to lowercase.  If the movement command is ‘vi-up-case’, swap the
     case of all characters on the current line.

‘up-case-word’ (‘ESC-U ESC-u’) (unbound) (unbound)

     Convert the current word to all caps and move past it.

‘yank’ (‘^Y’) (unbound) (unbound)

     Insert the contents of the kill buffer at the cursor position.

‘yank-pop’ (‘ESC-y’) (unbound) (unbound)

     Remove the text just yanked, rotate the kill-ring (the history of
     previously killed text) and yank the new top.  Only works following
     ‘yank’, ‘vi-put-before’, ‘vi-put-after’ or ‘yank-pop’.

‘vi-yank’ (unbound) (‘y’) (unbound)

     Read a movement command from the keyboard, and copy the region from
     the cursor position to the endpoint of the movement into the kill
     buffer.  If the command is ‘vi-yank’, copy the current line.

‘vi-yank-whole-line’ (unbound) (‘Y’) (unbound)

     Copy the current line into the kill buffer.

‘vi-yank-eol’

     Copy the region from the cursor position to the end of the line
     into the kill buffer.  Arguably, this is what Y should do in vi,
     but it isn’t what it actually does.


File: zsh.info,  Node: Arguments,  Next: Completion<3>,  Prev: Modifying Text,  Up: Standard Widgets

17.6.4 Arguments
----------------

‘digit-argument’ (‘ESC-0..ESC-9’) (‘1-9’) (unbound)

     Start a new numeric argument, or add to the current one.  See also
     ‘vi-digit-or-beginning-of-line’.  This only works if bound to a key
     sequence ending in a decimal digit.

     Inside a widget function, a call to this function treats the last
     key of the key sequence which called the widget as the digit.

‘neg-argument’ (‘ESC--’) (unbound) (unbound)

     Changes the sign of the following argument.

‘universal-argument’

     Multiply the argument of the next command by 4.  Alternatively, if
     this command is followed by an integer (positive or negative), use
     that as the argument for the next command.  Thus digits cannot be
     repeated using this command.  For example, if this command occurs
     twice, followed immediately by ‘forward-char’, move forward sixteen
     spaces; if instead it is followed by ‘-2’, then ‘forward-char’,
     move backward two spaces.

     Inside a widget function, if passed an argument, i.e.  ‘zle
     universal-argument’ NUM, the numeric argument will be set to NUM;
     this is equivalent to ‘NUMERIC=’NUM.

‘argument-base’

     Use the existing numeric argument as a numeric base, which must be
     in the range 2 to 36 inclusive.  Subsequent use of ‘digit-argument’
     and ‘universal-argument’ will input a new numeric argument in the
     given base.  The usual hexadecimal convention is used: the letter
     ‘a’ or ‘A’ corresponds to 10, and so on.  Arguments in bases
     requiring digits from 10 upwards are more conveniently input with
     ‘universal-argument’, since ‘ESC-a’ etc.  are not usually bound to
     ‘digit-argument’.

     The function can be used with a command argument inside a
     user-defined widget.  The following code sets the base to 16 and
     lets the user input a hexadecimal argument until a key out of the
     digit range is typed:

           zle argument-base 16
           zle universal-argument


File: zsh.info,  Node: Completion<3>,  Next: Miscellaneous,  Prev: Arguments,  Up: Standard Widgets

17.6.5 Completion
-----------------

‘accept-and-menu-complete’

     In a menu completion, insert the current completion into the
     buffer, and advance to the next possible completion.

‘complete-word’

     Attempt completion on the current word.

‘delete-char-or-list’ (‘^D’) (unbound) (unbound)

     Delete the character under the cursor.  If the cursor is at the end
     of the line, list possible completions for the current word.

‘expand-cmd-path’

     Expand the current command to its full pathname.

‘expand-or-complete’ (‘TAB’) (unbound) (‘TAB’)

     Attempt shell expansion on the current word.  If that fails,
     attempt completion.

‘expand-or-complete-prefix’

     Attempt shell expansion on the current word up to cursor.

‘expand-history’ (‘ESC-space ESC-!’) (unbound) (unbound)

     Perform history expansion on the edit buffer.

‘expand-word’ (‘^X*’) (unbound) (unbound)

     Attempt shell expansion on the current word.

‘list-choices’ (‘ESC-^D’) (‘^D =’) (‘^D’)

     List possible completions for the current word.

‘list-expand’ (‘^Xg ^XG’) (‘^G’) (‘^G’)

     List the expansion of the current word.

‘magic-space’

     Perform history expansion and insert a space into the buffer.  This
     is intended to be bound to space.

‘menu-complete’

     Like ‘complete-word’, except that menu completion is used.  See the
     ‘MENU_COMPLETE’ option.

‘menu-expand-or-complete’

     Like ‘expand-or-complete’, except that menu completion is used.

‘reverse-menu-complete’

     Perform menu completion, like ‘menu-complete’, except that if a
     menu completion is already in progress, move to the ‘previous’
     completion rather than the next.

‘end-of-list’

     When a previous completion displayed a list below the prompt, this
     widget can be used to move the prompt below the list.


File: zsh.info,  Node: Miscellaneous,  Next: Text Objects,  Prev: Completion<3>,  Up: Standard Widgets

17.6.6 Miscellaneous
--------------------

‘accept-and-hold’ (‘ESC-A ESC-a’) (unbound) (unbound)

     Push the contents of the buffer on the buffer stack and execute it.

‘accept-and-infer-next-history’

     Execute the contents of the buffer.  Then search the history list
     for a line matching the current one and push the event following
     onto the buffer stack.

‘accept-line’ (‘^J ^M’) (‘^J ^M’) (‘^J ^M’)

     Finish editing the buffer.  Normally this causes the buffer to be
     executed as a shell command.

‘accept-line-and-down-history’ (‘^O’) (unbound) (unbound)

     Execute the current line, and push the next history event on the
     buffer stack.

‘auto-suffix-remove’

     If the previous action added a suffix (space, slash, etc.)  to the
     word on the command line, remove it.  Otherwise do nothing.
     Removing the suffix ends any active menu completion or menu
     selection.

     This widget is intended to be called from user-defined widgets to
     enforce a desired suffix-removal behavior.

‘auto-suffix-retain’

     If the previous action added a suffix (space, slash, etc.)  to the
     word on the command line, force it to be preserved.  Otherwise do
     nothing.  Retaining the suffix ends any active menu completion or
     menu selection.

     This widget is intended to be called from user-defined widgets to
     enforce a desired suffix-preservation behavior.

‘beep’

     Beep, unless the ‘BEEP’ option is unset.

‘bracketed-paste’ (‘^[[200~’) (‘^[[200~’) (‘^[[200~’)

     This widget is invoked when text is pasted to the terminal
     emulator.  It is not intended to be bound to actual keys but
     instead to the special sequence generated by the terminal emulator
     when text is pasted.

     When invoked interactively, the pasted text is inserted to the
     buffer and placed in the cutbuffer.  If a numeric argument is
     given, shell quoting will be applied to the pasted text before it
     is inserted.

     When a named buffer is specified with ‘vi-set-buffer’ (‘"x’), the
     pasted text is stored in that named buffer but not inserted.

     When called from a widget function as ‘`bracketed-paste’ NAME‘, the
     pasted text is assigned to the variable NAME and no other
     processing is done.

     See also the ‘zle_bracketed_paste’ parameter.

‘vi-cmd-mode’ (‘^X^V’) (unbound) (^[)

     Enter command mode; that is, select the ‘vicmd’ keymap.  Yes, this
     is bound by default in emacs mode.

‘vi-caps-lock-panic’

     Hang until any lowercase key is pressed.  This is for vi users
     without the mental capacity to keep track of their caps lock key
     (like the author).

‘clear-screen’ (‘^L ESC-^L’) (‘^L’) (‘^L’)

     Clear the screen and redraw the prompt.

‘deactivate-region’

     Make the current region inactive.  This disables vim-style visual
     selection mode if it is active.

‘describe-key-briefly’

     Reads a key sequence, then prints the function bound to that
     sequence.

‘exchange-point-and-mark’ (‘^X^X’) (unbound) (unbound)

     Exchange the cursor position (point) with the position of the mark.
     Unless a negative numeric argument is given, the region between
     point and mark is activated so that it can be highlighted.  If a
     zero numeric argument is given, the region is activated but point
     and mark are not swapped.

‘execute-named-cmd’ (‘ESC-x’) (:) (unbound)

     Read the name of an editor command and execute it.  Aliasing this
     widget with ‘zle -A’ or replacing it with ‘zle -N’ has no effect
     when interpreting key bindings, but ‘zle execute-named-cmd’ will
     invoke such an alias or replacement.

     A restricted set of editing functions is available in the
     mini-buffer.  Keys are looked up in the special ‘command’ keymap,
     and if not found there in the main keymap.  An interrupt signal, as
     defined by the stty setting, will abort the function.  Note that
     the following always perform the same task within the
     ‘executed-named-cmd’ environment and cannot be replaced by user
     defined widgets, nor can the set of functions be extended.  The
     allowed functions are: ‘backward-delete-char’,
     ‘vi-backward-delete-char’, ‘clear-screen’, ‘redisplay’,
     ‘quoted-insert’, ‘vi-quoted-insert’, ‘backward-kill-word’,
     ‘vi-backward-kill-word’, ‘kill-whole-line’, ‘vi-kill-line’,
     ‘backward-kill-line’, ‘list-choices’, ‘delete-char-or-list’,
     ‘complete-word’, ‘accept-line’, ‘expand-or-complete’ and
     ‘expand-or-complete-prefix’.

     ‘kill-region’ kills the last word, and vi-cmd-mode is treated the
     same as accept-line.  The space and tab characters, if not bound to
     one of these functions, will complete the name and then list the
     possibilities if the ‘AUTO_LIST’ option is set.  Any other
     character that is not bound to ‘self-insert’ or
     ‘self-insert-unmeta’ will beep and be ignored.  The bindings of the
     current insert mode will be used.

     Currently this command may not be redefined or called by name.

‘execute-last-named-cmd’ (‘ESC-z’) (unbound) (unbound)

     Redo the last function executed with ‘execute-named-cmd’.

     Like ‘execute-named-cmd’, this command may not be redefined, but it
     may be called by name.

‘get-line’ (‘ESC-G ESC-g’) (unbound) (unbound)

     Pop the top line off the buffer stack and insert it at the cursor
     position.

‘pound-insert’ (unbound) (#) (unbound)

     If there is no # character at the beginning of the buffer, add one
     to the beginning of each line.  If there is one, remove a # from
     each line that has one.  In either case, accept the current line.
     The ‘INTERACTIVE_COMMENTS’ option must be set for this to have any
     usefulness.

‘vi-pound-insert’

     If there is no # character at the beginning of the current line,
     add one.  If there is one, remove it.  The ‘INTERACTIVE_COMMENTS’
     option must be set for this to have any usefulness.

‘push-input’

     Push the entire current multiline construct onto the buffer stack
     and return to the top-level (‘PS1’) prompt.  If the current parser
     construct is only a single line, this is exactly like ‘push-line’.
     Next time the editor starts up or is popped with ‘get-line’, the
     construct will be popped off the top of the buffer stack and loaded
     into the editing buffer.

‘push-line’ (‘^Q ESC-Q ESC-q’) (unbound) (unbound)

     Push the current buffer onto the buffer stack and clear the buffer.
     Next time the editor starts up, the buffer will be popped off the
     top of the buffer stack and loaded into the editing buffer.

‘push-line-or-edit’

     At the top-level (‘PS1’) prompt, equivalent to ‘push-line’.  At a
     secondary (‘PS2’) prompt, move the entire current multiline
     construct into the editor buffer.  The latter is equivalent to
     ‘push-input’ followed by ‘get-line’.

‘read-command’

     Only useful from a user-defined widget.  A keystroke is read just
     as in normal operation, but instead of the command being executed
     the name of the command that would be executed is stored in the
     shell parameter ‘REPLY’.  This can be used as the argument of a
     future ‘zle’ command.  If the key sequence is not bound, status 1
     is returned; typically, however, ‘REPLY’ is set to ‘undefined-key’
     to indicate a useless key sequence.

‘recursive-edit’

     Only useful from a user-defined widget.  At this point in the
     function, the editor regains control until one of the standard
     widgets which would normally cause zle to exit (typically an
     ‘accept-line’ caused by hitting the return key) is executed.
     Instead, control returns to the user-defined widget.  The status
     returned is non-zero if the return was caused by an error, but the
     function still continues executing and hence may tidy up.  This
     makes it safe for the user-defined widget to alter the command line
     or key bindings temporarily.

     The following widget, ‘caps-lock’, serves as an example.

           self-insert-ucase() {
             LBUFFER+=${(U)KEYS[-1]}
           }

           integer stat

           zle -N self-insert self-insert-ucase
           zle -A caps-lock save-caps-lock
           zle -A accept-line caps-lock

           zle recursive-edit
           stat=$?

           zle -A .self-insert self-insert
           zle -A save-caps-lock caps-lock
           zle -D save-caps-lock

           (( stat )) && zle send-break

           return $stat

     This causes typed letters to be inserted capitalised until either
     ‘accept-line’ (i.e.  typically the return key) is typed or the
     ‘caps-lock’ widget is invoked again; the later is handled by saving
     the old definition of ‘caps-lock’ as ‘save-caps-lock’ and then
     rebinding it to invoke ‘accept-line’.  Note that an error from the
     recursive edit is detected as a non-zero return status and
     propagated by using the ‘send-break’ widget.

‘redisplay’ (unbound) (‘^R’) (‘^R’)

     Redisplays the edit buffer.

‘reset-prompt’ (unbound) (unbound) (unbound)

     Force the prompts on both the left and right of the screen to be
     re-expanded, then redisplay the edit buffer.  This reflects changes
     both to the prompt variables themselves and changes in the
     expansion of the values (for example, changes in time or directory,
     or changes to the value of variables referred to by the prompt).

     Otherwise, the prompt is only expanded each time zle starts, and
     when the display has been interrupted by output from another part
     of the shell (such as a job notification) which causes the command
     line to be reprinted.

     ‘reset-prompt’ doesn’t alter the special parameter ‘LASTWIDGET’.

‘send-break’ (‘^G ESC-^G’) (unbound) (unbound)

     Abort the current editor function, e.g.  ‘execute-named-command’,
     or the editor itself, e.g.  if you are in ‘vared’.  Otherwise abort
     the parsing of the current line; in this case the aborted line is
     available in the shell variable ‘ZLE_LINE_ABORTED’.  If the editor
     is aborted from within ‘vared’, the variable ‘ZLE_VARED_ABORTED’ is
     set.

‘run-help’ (‘ESC-H ESC-h’) (unbound) (unbound)

     Push the buffer onto the buffer stack, and execute the command
     ‘run-help’ CMD, where CMD is the current command.  ‘run-help’ is
     normally aliased to ‘man’.

‘vi-set-buffer’ (unbound) (”) (unbound)

     Specify a buffer to be used in the following command.  There are 39
     buffers that can be specified: the 26 ‘named’ buffers ‘"a’ to ‘"z’,
     the ‘yank’ buffer ‘"0’, the nine ‘queued’ buffers ‘"1’ to ‘"9’, the
     ‘black hole’ buffer ‘"_’ and the system selection “* and clipboard
     “+.  The named buffers can also be specified as ‘"A’ to ‘"Z’.

     When a buffer is specified for a cut, change or yank command, the
     text concerned replaces the previous contents of the specified
     buffer.  If a named buffer is specified using a capital, the newly
     cut text is appended to the buffer instead of overwriting it.  When
     using the ‘"_’ buffer, nothing happens.  This can be useful for
     deleting text without affecting any buffers.

     Accessing and updating the system clipboard relies on specific
     support from the terminal.

     If no buffer is specified for a cut or change command, ‘"1’ is
     used, and the contents of ‘"1’ to ‘"8’ are each shifted along one
     buffer; the contents of ‘"9’ is lost.  If no buffer is specified
     for a yank command, ‘"0’ is used.  Finally, a paste command without
     a specified buffer will paste the text from the most recent command
     regardless of any buffer that might have been used with that
     command.

     When called from a widget function by the ‘zle’ command, the buffer
     can optionally be specified with an argument.  For example,

           zle vi-set-buffer A

‘vi-set-mark’ (unbound) (‘m’) (unbound)

     Set the specified mark at the cursor position.

‘set-mark-command’ (^@) (unbound) (unbound)

     Set the mark at the cursor position.  If called with a negative
     numeric argument, do not set the mark but deactivate the region so
     that it is no longer highlighted (it is still usable for other
     purposes).  Otherwise the region is marked as active.

‘spell-word’ (‘ESC-$ ESC-S ESC-s’) (unbound) (unbound)

     Attempt spelling correction on the current word.

‘split-undo’

     Breaks the undo sequence at the current change.  This is useful in
     vi mode as changes made in insert mode are coalesced on entering
     command mode.  Similarly, ‘undo’ will normally revert as one all
     the changes made by a user-defined widget.

‘undefined-key’

     This command is executed when a key sequence that is not bound to
     any command is typed.  By default it beeps.

‘undo’ (‘^_ ^Xu ^X^U’) (‘u’) (unbound)

     Incrementally undo the last text modification.  When called from a
     user-defined widget, takes an optional argument indicating a
     previous state of the undo history as returned by the
     ‘UNDO_CHANGE_NO’ variable; modifications are undone until that
     state is reached, subject to any limit imposed by the
     ‘UNDO_LIMIT_NO’ variable.

     Note that when invoked from vi command mode, the full prior change
     made in insert mode is reverted, the changes having been merged
     when command mode was selected.

‘redo’ (unbound) (‘^R’) (unbound)

     Incrementally redo undone text modifications.

‘vi-undo-change’ (unbound) (unbound) (unbound)

     Undo the last text modification.  If repeated, redo the
     modification.

‘visual-mode’ (unbound) (‘v’) (unbound)

     Toggle vim-style visual selection mode.  If line-wise visual mode
     is currently enabled then it is changed to being character-wise.
     If used following an operator, it forces the subsequent movement
     command to be treated as a character-wise movement.

‘visual-line-mode’ (unbound) (‘V’) (unbound)

     Toggle vim-style line-wise visual selection mode.  If
     character-wise visual mode is currently enabled then it is changed
     to being line-wise.  If used following an operator, it forces the
     subsequent movement command to be treated as a line-wise movement.

‘what-cursor-position’ (‘^X=’) (‘ga’) (unbound)

     Print the character under the cursor, its code as an octal, decimal
     and hexadecimal number, the current cursor position within the
     buffer and the column of the cursor in the current line.

‘where-is’

     Read the name of an editor command and print the listing of key
     sequences that invoke the specified command.  A restricted set of
     editing functions is available in the mini-buffer.  Keys are looked
     up in the special ‘command’ keymap, and if not found there in the
     main keymap.

‘which-command’ (‘ESC-?’) (unbound) (unbound)

     Push the buffer onto the buffer stack, and execute the command
     ‘which-command’ CMD, where CMD is the current command.
     ‘which-command’ is normally aliased to ‘whence’.

‘vi-digit-or-beginning-of-line’ (unbound) (‘0’) (unbound)

     If the last command executed was a digit as part of an argument,
     continue the argument.  Otherwise, execute vi-beginning-of-line.


File: zsh.info,  Node: Text Objects,  Prev: Miscellaneous,  Up: Standard Widgets

17.6.7 Text Objects
-------------------

Text objects are commands that can be used to select a block of text
according to some criteria.  They are a feature of the vim text editor
and so are primarily intended for use with vi operators or from visual
selection mode.  However, they can also be used from vi-insert or emacs
mode.  Key bindings listed below apply to the ‘viopp’ and ‘visual’
keymaps.

‘select-a-blank-word’ (‘aW’)

     Select a word including adjacent blanks, where a word is defined as
     a series of non-blank characters.  With a numeric argument,
     multiple words will be selected.

‘select-a-shell-word’ (‘aa’)

     Select the current command argument applying the normal rules for
     quoting.

‘select-a-word’ (‘aw’)

     Select a word including adjacent blanks, using the normal vi-style
     word definition.  With a numeric argument, multiple words will be
     selected.

‘select-in-blank-word’ (‘iW’)

     Select a word, where a word is defined as a series of non-blank
     characters.  With a numeric argument, multiple words will be
     selected.

‘select-in-shell-word’ (‘ia’)

     Select the current command argument applying the normal rules for
     quoting.  If the argument begins and ends with matching quote
     characters, these are not included in the selection.

‘select-in-word’ (‘iw’)

     Select a word, using the normal vi-style word definition.  With a
     numeric argument, multiple words will be selected.


File: zsh.info,  Node: Terminal Extensions,  Next: Character Highlighting,  Prev: Standard Widgets,  Up: Zsh Line Editor

17.7 Terminal Extensions
========================

Modern terminals often carry functionality that is not covered by the
‘terminfo’ library.  For these cases, the availability of a feature can
be asserted by including it in the array parameter ‘.term.extensions’.
Similarly the absence of a feature can be indicated via it’s inclusion
with a - prefix.  Where a feature isn’t listed, the status of terminal
support is unknown and defaults apply as to whether ZLE will use the
feature.  This is often harmless as terminals ignore extra instructions
they don’t recognise.  Even if your terminal does support a particular
extension, you may choose to list it with an initial - as a way to
disable the associated feature.  Many extensions are named with common
prefixes to group related extensions.  This allows a whole class of
extensions to be disabled with a single entry such as by adding
‘-cursor’ to disable cursor shape and color changing.

When ZLE starts, it will add entries for features that were
auto-detected.  This auto-detection uses extensions itself, all named
with a ‘query’ prefix.  As this happens when ZLE starts, disabling them
needs to be done early in the startup files.  A value of ‘-query’ will
disable all terminal queries on startup, including those that query
terminal properties such as colors rather than detecting features.
Populating the array with the status of auto-detected features will mean
that associated terminal queries are not needed and will be skipped.

Extensions can be any of the following, where the marks ‘<D>’ and ‘<E>’
indicate whether each one is disabled or enabled by default:

‘bracketed-paste’ <E>

     Many terminal emulators have a feature that allows applications to
     identify when text is pasted into the terminal rather than being
     typed normally.  For ZLE, this means that special characters such
     as tabs and newlines can be inserted instead of invoking editor
     commands.  Furthermore, pasted text forms a single undo event and
     if the region is active, pasted text will replace the region.

‘cursor-color’ <E>

     Support for changing the color of the cursor.

‘cursor-shape’ <E>

     Support for changing the shape of the cursor.

‘integration-output’ <E>

     This provides the terminal with semantic information regarding
     where the output from commands start and finish.  Some terminals
     use this information to make it easy to select just the output from
     a single command.

‘integration-prompt’ <E>

     This informs the terminal when the shell displays a prompt.  This
     enables a variety of terminal features such as displaying markers,
     allowing you to jump to previous commands in the scroll-back buffer
     and ensuring that right prompts are handled correctly when the
     window is resized.  The end of the prompt also provides the
     terminal with a marker for the start of user input.

‘integration-pwd’ <E>

     This advises the terminal of the shell’s current directory which
     allows it to create new windows with the same current working
     directory.

‘query-bg’ <E>

     Query the terminal background color which is used for ‘.term.bg’
     and ‘.term.mode’.

‘query-cursorcolor’ <E>

     Query the cursor color.  This facilitates restoring the cursor to
     its original color if it has been configured via ‘zle_cursorform’.
     The color is also assigned to ‘.term.cursor’.

‘query-fg’ <E>

     Query the terminal foreground color which is used for ‘.term.fg’.

‘query-id’ <E>

     Query the terminal identification which is used for ‘.term.id’ and
     ‘.term.version’.

‘modkeys-kitty’ <D>

‘query-modkeys-kitty’ <D>

     Support for the kitty keyboard handling protocol which enables
     reporting of a wider range of key combinations and resolves
     problems with ambiguous key sequences.  Currently there is only
     support for detecting whether the terminal supports this feature.

‘modkeys-xterm’ <D>

     Support for the keyboard handling sequences associated with xterm’s
     ‘modifyOtherKeys’ X resource.  This enables reporting of a wider
     range of key combinations and resolves some problems with ambiguous
     key sequences.

‘truecolor’ <D>

‘query-truecolor’ <E>

     Support for 24-bit truecolor escape sequences.  Auto-detection also
     tries termcap and the ‘COLORTERM’ environment variable.


File: zsh.info,  Node: Character Highlighting,  Next: Cursor Shape and Color,  Prev: Terminal Extensions,  Up: Zsh Line Editor

17.8 Character Highlighting
===========================

The line editor has the ability to highlight characters or regions of
the line that have a particular significance.  This is controlled by the
array parameter ‘zle_highlight’, if it has been set by the user.

If the parameter contains the single entry ‘none’ all highlighting is
turned off.  Note the parameter is still expected to be an array.

Otherwise each entry of the array should consist of a word indicating a
context for highlighting, then a colon, then a comma-separated list of
the types of highlighting to apply in that context.

The contexts available for highlighting are the following:

‘default’

     Any text within the command line not affected by any other
     highlighting.  Text outside the editable area of the command line
     is not affected.

‘isearch’

     When one of the incremental history search widgets is active, the
     area of the command line matched by the search string or pattern.

‘region’

     The currently selected text.  In emacs terminology, this is
     referred to as the region and is bounded by the cursor (point) and
     the mark.  The region is only highlighted if it is active, which is
     the case after the mark is modified with ‘set-mark-command’ or
     ‘exchange-point-and-mark’.  Note that whether or not the region is
     active has no effect on its use within emacs style widgets, it
     simply determines whether it is highlighted.  In vi mode, the
     region corresponds to selected text in visual mode.

‘special’

     Individual characters that have no direct printable representation
     but are shown in a special manner by the line editor.  These
     characters are described below.

‘suffix’

     This context is used in completion for characters that are marked
     as suffixes that will be removed if the completion ends at that
     point, the most obvious example being a slash (/) after a directory
     name.  Note that suffix removal is configurable; the circumstances
     under which the suffix will be removed may differ for different
     completions.

‘paste’

     Following a command to paste text, the characters that were
     inserted.

‘ellipsis’

     Markers used to indicate where the text doesn’t fit within the
     terminal.

When ‘region_highlight’ is set, the contexts that describe a region –
‘isearch’, ‘region’, ‘suffix’, and ‘paste’ – are applied first, then
‘region_highlight’ is applied, then the remaining ‘zle_highlight’
contexts are applied.  If a particular character is affected by multiple
specifications, the last specification wins.

‘zle_highlight’ may contain additional fields for controlling how
terminal sequences to change colours are output.  Each of the following
is followed by a colon and a string in the same form as for key
bindings.  This will not be necessary for the vast majority of terminals
as the defaults shown in parentheses are widely used.

‘fg_start_code’ (‘\e[3’)

     The start of the escape sequence for the foreground colour.  This
     is followed by one to three ASCII digits representing the colour.
     Only used for palette colors, i.e.  not 24-bit colors specified via
     a color triplet.

‘fg_default_code’ (‘9’)

     The number to use instead of the colour to reset the default
     foreground colour.

‘fg_end_code’ (‘m’)

     The end of the escape sequence for the foreground colour.

‘bg_start_code’ (‘\e[4’)

     The start of the escape sequence for the background colour.  See
     ‘fg_start_code’ above.

‘bg_default_code’ (‘9’)

     The number to use instead of the colour to reset the default
     background colour.

‘bg_end_code’ (‘m’)

     The end of the escape sequence for the background colour.

The available types of highlighting are the following.  Note that not
all types of highlighting are available on all terminals:

‘none’

     No additional highlighting is applied to the given context.  It is
     not useful for this to appear with other types of highlighting; it
     is used to override a default.  Any inherited highlighting is
     retained so for example, with ‘region:none’, highlighting
     associated with ‘default’ is still used for the region.

‘reset’

     The terminal’s default highlighting is applied to the given
     context.  This can be useful as a way to clear all inherited
     highlighting, so may be used before naming other types of
     highlighting.

‘fg=’COLOUR

     The foreground colour should be set to COLOUR, a decimal integer,
     the name of one of the eight most widely-supported colours or as a
     # followed by an RGB triplet in hexadecimal format.

     Not all terminals support this and, of those that do, not all
     provide facilities to test the support, hence the user should
     decide based on the terminal type.  Most terminals support the
     colours ‘black’, ‘red’, ‘green’, ‘yellow’, ‘blue’, ‘magenta’,
     ‘cyan’ and ‘white’, which can be set by name.  In addition.
     ‘default’ may be used to set the terminal’s default foreground
     colour.  Abbreviations are allowed; ‘b’ or ‘bl’ selects black.
     Some terminals may generate additional colours if the ‘bold’
     attribute is also present.

     On recent terminals and on systems with an up-to-date terminal
     database the number of colours supported may be tested by the
     command ‘echotc Co’; if this succeeds, it indicates a limit on the
     number of colours which will be enforced by the line editor.  The
     number of colours is in any case limited to 256 (i.e.  the range 0
     to 255).

     Some modern terminal emulators have support for 24-bit true colour
     (16 million colours).  In this case, the hex triplet format can be
     used.  This consists of a # followed by either a three or six digit
     hexadecimal number describing the red, green and blue components of
     the colour.  Hex triplets can also be used with 88 and 256 colour
     terminals via the ‘zsh/nearcolor’ module (see ‘zshmodules’).

     Colour is also known as color.

‘bg=’COLOUR

     The background colour should be set to COLOUR.  This works
     similarly to the foreground colour, except the background is not
     usually affected by the bold attribute.

‘bold’

     The characters in the given context are shown with a bold font
     weight.  Not all terminals distinguish bold fonts.

‘faint’

     The characters in the given context are shown with a faint font
     weight.  Not all terminals distinguish faint fonts.

‘standout’

     The characters in the given context are shown in the terminal’s
     standout mode.  The actual effect is specific to the terminal; on
     many terminals it is inverse video.  On some such terminals, where
     the cursor does not blink it appears with standout mode negated,
     making it less than clear where the cursor actually is.  On such
     terminals one of the other effects may be preferable for
     highlighting the region and matched search string.

‘underline’

     The characters in the given context are shown underlined.  Some
     terminals show the foreground in a different colour instead; in
     this case whitespace will not be highlighted.

‘italic’

     The characters in the given context are shown in a italic font.
     Not all terminals support italic fonts.

‘hl=’GROUP

     Use the specified highlighting group.  The GROUP is used as a key
     into the associative array ‘.zle.hlgroups’ to determine the actual
     highlighting.

‘layer=’LAYER

     The layer is used to determine precedence when multiple
     highlighting regions overlap.  The LAYER is a decimal integer, with
     higher numbers taking precedence over lower numbers.  This cannot
     be used with the ‘default’ and ‘ellipsis’ fields of ‘zle_highlight’
     because they treated as base layers.  With the other fields 30
     applies by default for ‘special’, 20 for ‘region’ and ‘isearch’ and
     15 for ‘paste’.  Highlighting defined in ‘region_highlight’
     defaults to layer 10 and would take precedence over highlighting
     for any fields of ‘zle_highlight’ that are assigned to the same
     layer.

‘opacity=’FG‘%’[/BG‘%’]

     Instead of replacing colors in higher layers, the colors can be
     mixed.  The opacity is specified as a percentage where ‘0%’ is
     fully transparent and ‘100%’ represents the default behavior of
     replacing the underlying colour.  If a single value is specified,
     it applies to both foreground and background.

In addition, the simple highlighting types can be prefixed with ‘"no"’
to explicitly disable them.  This is useful where highlighting is merged
with inherited highlighting from other definitions.  Note that ‘nobold’
selects a normal font weight so also has the effect of disabling
‘faint’.

The characters described above as ‘special’ are as follows.  The
formatting described here is used irrespective of whether the characters
are highlighted:

ASCII control characters

     Control characters in the ASCII range are shown as ^ followed by
     the base character.

Unprintable multibyte characters

     This item applies to control characters not in the ASCII range,
     plus other characters as follows.  If the ‘MULTIBYTE’ option is in
     effect, multibyte characters not in the ASCII character set that
     are reported as having zero width are treated as combining
     characters when the option ‘COMBINING_CHARS’ is on.  If the option
     is off, or if a character appears where a combining character is
     not valid, the character is treated as unprintable.

     Unprintable multibyte characters are shown as a hexadecimal number
     between angle brackets.  The number is the code point of the
     character in the wide character set; this may or may not be
     Unicode, depending on the operating system.

Invalid multibyte characters

     If the ‘MULTIBYTE’ option is in effect, any sequence of one or more
     bytes that does not form a valid character in the current character
     set is treated as a series of bytes each shown as a special
     character.  This case can be distinguished from other unprintable
     characters as the bytes are represented as two hexadecimal digits
     between angle brackets, as distinct from the four or eight digits
     that are used for unprintable characters that are nonetheless valid
     in the current character set.

     Not all systems support this: for it to work, the system’s
     representation of wide characters must be code values from the
     Universal Character Set, as defined by IS0 10646 (also known as
     Unicode).

Wrapped double-width characters

     When a double-width character appears in the final column of a
     line, it is instead shown on the next line.  The empty space left
     in the original position is highlighted as a special character.

If ‘zle_highlight’ is not set or no value applies to a particular
context, the defaults applied are equivalent to

      zle_highlight=(region:standout special:standout
      suffix:bold isearch:underline paste:standout)

i.e.  both the region and special characters are shown in standout mode.

Within widgets, arbitrary regions may be highlighted by setting the
special array parameter ‘region_highlight’; see

Zle Widgets

.


File: zsh.info,  Node: Cursor Shape and Color,  Prev: Character Highlighting,  Up: Zsh Line Editor

17.9 Cursor Shape and Color
===========================

Some terminals support the ability to change the shape and color of the
cursor.  On such terminals, the line editor will use cursor styles
appropriate to different contexts.  This is controlled via the array
parameter ‘zle_cursorform’.  To disable all cursor changes, see the
‘.term.extensions’ parameter.

Each element of the array should consist of a word indicating a context
followed by a colon, then a comma-separated list of properties
describing the shape and color to apply to the cursor.

The available contexts follow with the default value shown in
parentheses.  Where no default is given, the terminal’s default is
applied:

‘command’

     Used for vi normal mode.

‘edit’

     The default form used in the line editor and for editing text in
     emacs mode.

‘insert’ (‘bar’)

     Used for vi editing mode.

‘overwrite’

     Used when editing text in overwrite mode or with the vi replace
     command.

‘pending’ (‘underline’)

     Used where the line editor is waiting for a single key press such
     as the vi operator pending mode widget.

‘region’

     Applied for both ‘regionstart’ and ‘regionend’ contexts.

‘regionstart’

     Used when the region is active and the cursor is positioned at the
     start of the region.  The region includes the text under the cursor
     when it is positioned at the start so it is best to configure the
     cursor so that it does not obscure this fact.

‘regionend’

     Used when the region is active and the cursor is positioned at the
     end of the region.  Note that when this is the case, the region
     does not include the cursor position.

‘visual’

     Used when vi visual mode is active.  The visual selection always
     includes the cursor position so the same advice as for
     ‘regionstart’ applies.

The available cursor shapes are ‘none’, ‘bar’, ‘block’, ‘underline’ and
‘hidden’.  Additionally, you can specify either ‘blink’ or ‘steady’ to
indicate whether the cursor should flash and specify a color as an RGB
triplet in hexadecimal format with ‘color=’#XXXXXX.  The value ‘none’
applies the terminal’s defaults.  Note that on many terminals, this may
differ from the initial cursor state from when the shell started.


File: zsh.info,  Node: Completion Widgets,  Next: Completion System,  Prev: Zsh Line Editor,  Up: Top

18 Completion Widgets
*********************

* Menu:

* Description: Description<4>.
* Completion Special Parameters::
* Completion Builtin Commands::
* Completion Condition Codes::
* Completion Matching Control::
* Completion Widget Example::


File: zsh.info,  Node: Description<4>,  Next: Completion Special Parameters,  Up: Completion Widgets

18.1 Description
================

The shell’s programmable completion mechanism can be manipulated in two
ways; here the low-level features supporting the newer, function-based
mechanism are defined.  A complete set of shell functions based on these
features is described in

the next chapter, Completion System

, and users with no interest in adding to that system (or, potentially,
writing their own – see dictionary entry for ‘hubris’) should skip the
current section.  The older system based on the ‘compctl’ builtin
command is described in ‘zshcompctl’.

Completion widgets are defined by the ‘-C’ option to the ‘zle’ builtin
command provided by the ‘zsh/zle’ module (see *note Zle Builtins: ba.).
For example,

      zle -C complete expand-or-complete completer

defines a widget named ‘complete’.  The second argument is the name of
any of the builtin widgets that handle completions: ‘complete-word’,
‘expand-or-complete’, ‘expand-or-complete-prefix’, ‘menu-complete’,
‘menu-expand-or-complete’, ‘reverse-menu-complete’, ‘list-choices’, or
‘delete-char-or-list’.  Note that this will still work even if the
widget in question has been re-bound.

When this newly defined widget is bound to a key using the ‘bindkey’
builtin command defined in the ‘zsh/zle’ module (see *note Zle Builtins:
ba.), typing that key will call the shell function ‘completer’.  This
function is responsible for generating completion matches using the
builtins described below.  As with other ZLE widgets, the function is
called with its standard input closed.

Once the function returns, the completion code takes over control again
and treats the matches in the same manner as the specified builtin
widget, in this case ‘expand-or-complete’.


File: zsh.info,  Node: Completion Special Parameters,  Next: Completion Builtin Commands,  Prev: Description<4>,  Up: Completion Widgets

18.2 Completion Special Parameters
==================================

The parameters ‘ZLE_REMOVE_SUFFIX_CHARS’ and ‘ZLE_SPACE_SUFFIX_CHARS’
are used by the completion mechanism, but are not special.  See *note
Parameters Used by the Shell: 11.

Inside completion widgets, and any functions called from them, some
parameters have special meaning; outside these functions they are not
special to the shell in any way.  These parameters are used to pass
information between the completion code and the completion widget.  Some
of the builtin commands and the condition codes use or change the
current values of these parameters.  Any existing values will be hidden
during execution of completion widgets; except for ‘compstate’, the
parameters are reset on each function exit (including nested function
calls from within the completion widget) to the values they had when the
function was entered.

‘CURRENT’

     This is the number of the current word, i.e.  the word the cursor
     is currently on in the ‘words’ array.  Note that this value is only
     correct if the ‘ksharrays’ option is not set.

‘IPREFIX’

     Initially this will be set to the empty string.  This parameter
     functions like ‘PREFIX’; it contains a string which precedes the
     one in ‘PREFIX’ and is not considered part of the list of matches.
     Typically, a string is transferred from the beginning of ‘PREFIX’
     to the end of ‘IPREFIX’, for example:

           IPREFIX=${PREFIX%%\=*}=
           PREFIX=${PREFIX#*=}

     causes the part of the prefix up to and including the first equal
     sign not to be treated as part of a matched string.  This can be
     done automatically by the ‘compset’ builtin, see below.

‘ISUFFIX’

     As ‘IPREFIX’, but for a suffix that should not be considered part
     of the matches; note that the ‘ISUFFIX’ string follows the ‘SUFFIX’
     string.

‘PREFIX’

     Initially this will be set to the part of the current word from the
     beginning of the word up to the position of the cursor; it may be
     altered to give a common prefix for all matches.

‘QIPREFIX’

     This parameter is read-only and contains the quoted string up to
     the word being completed.  E.g.  when completing ‘"foo’, this
     parameter contains the double quote.  If the ‘-q’ option of
     ‘compset’ is used (see below), and the original string was ‘"foo
     bar’ with the cursor on the ‘bar’, this parameter contains ‘"foo’ .

‘QISUFFIX’

     Like ‘QIPREFIX’, but containing the suffix.

‘SUFFIX’

     Initially this will be set to the part of the current word from the
     cursor position to the end; it may be altered to give a common
     suffix for all matches.  It is most useful when the option
     ‘COMPLETE_IN_WORD’ is set, as otherwise the whole word on the
     command line is treated as a prefix.

‘compstate’

     This is an associative array with various keys and values that the
     completion code uses to exchange information with the completion
     widget.  The keys are:

     ‘all_quotes’

          The ‘-q’ option of the ‘compset’ builtin command (see below)
          allows a quoted string to be broken into separate words; if
          the cursor is on one of those words, that word will be
          completed, possibly invoking ‘compset -q’ recursively.  With
          this key it is possible to test the types of quoted strings
          which are currently broken into parts in this fashion.  Its
          value contains one character for each quoting level.  The
          characters are a single quote or a double quote for strings
          quoted with these characters, a dollars sign for strings
          quoted with ‘$'’…‘'’ and a backslash for strings not starting
          with a quote character.  The first character in the value
          always corresponds to the innermost quoting level.

     ‘context’

          This will be set by the completion code to the overall context
          in which completion is attempted.  Possible values are:

          ‘array_value’

               when completing inside the value of an array parameter
               assignment; in this case the ‘words’ array contains the
               words inside the parentheses.

          ‘brace_parameter’

               when completing the name of a parameter in a parameter
               expansion beginning with ‘${’.  This context will also be
               set when completing parameter flags following ‘${(’; the
               full command line argument is presented and the handler
               must test the value to be completed to ascertain that
               this is the case.

          ‘assign_parameter’

               when completing the name of a parameter in a parameter
               assignment.

          ‘command’

               when completing for a normal command (either in command
               position or for an argument of the command).

          ‘condition’

               when completing inside a ‘[[...]]’ conditional
               expression; in this case the ‘words’ array contains only
               the words inside the conditional expression.

          ‘math’

               when completing in a mathematical environment such as a
               ‘((...))’ construct.

          ‘parameter’

               when completing the name of a parameter in a parameter
               expansion beginning with ‘$’ but not ‘${’.

          ‘redirect’

               when completing after a redirection operator.

          ‘subscript’

               when completing inside a parameter subscript.

          ‘value’

               when completing the value of a parameter assignment.

     ‘exact’

          Controls the behaviour when the ‘REC_EXACT’ option is set.  It
          will be set to ‘accept’ if an exact match would be accepted,
          and will be unset otherwise.

          If it was set when at least one match equal to the string on
          the line was generated, the match is accepted.

     ‘exact_string’

          The string of an exact match if one was found, otherwise
          unset.

     ‘ignored’

          The number of completions that were ignored because they
          matched one of the patterns given with the ‘-F’ option to the
          ‘compadd’ builtin command.

     ‘insert’

          This controls the manner in which a match is inserted into the
          command line.  On entry to the widget function, if it is unset
          the command line is not to be changed; if set to
          ‘unambiguous’, any prefix common to all matches is to be
          inserted; if set to ‘automenu-unambiguous’, the common prefix
          is to be inserted and the next invocation of the completion
          code may start menu completion (due to the ‘AUTO_MENU’ option
          being set); if set to ‘menu’ or ‘automenu’ menu completion
          will be started for the matches currently generated (in the
          latter case this will happen because the ‘AUTO_MENU’ is set).
          The value may also contain the string ‘tab’ when the
          completion code would normally not really do completion, but
          only insert the TAB character.

          On exit it may be set to any of the values above (where
          setting it to the empty string is the same as unsetting it),
          or to a number, in which case the match whose number is given
          will be inserted into the command line.  Negative numbers
          count backward from the last match (with ‘-1’ selecting the
          last match) and out-of-range values are wrapped around, so
          that a value of zero selects the last match and a value one
          more than the maximum selects the first.  Unless the value of
          this key ends in a space, the match is inserted as in a menu
          completion, i.e.  without automatically appending a space.

          Both ‘menu’ and ‘automenu’ may also specify the number of the
          match to insert, given after a colon.  For example, ‘menu:2’
          says to start menu completion, beginning with the second
          match.

          Note that a value containing the substring ‘tab’ makes the
          matches generated be ignored and only the TAB be inserted.

          Finally, it may also be set to ‘all’, which makes all matches
          generated be inserted into the line.

     ‘insert_positions’

          When the completion system inserts an unambiguous string into
          the line, there may be multiple places where characters are
          missing or where the character inserted differs from at least
          one match.  The value of this key contains a colon separated
          list of all these positions, as indexes into the command line.

     ‘last_prompt’

          If this is set to a non-empty string for every match added,
          the completion code will move the cursor back to the previous
          prompt after the list of completions has been displayed.
          Initially this is set or unset according to the
          ‘ALWAYS_LAST_PROMPT’ option.

     ‘list’

          This controls whether or how the list of matches will be
          displayed.  If it is unset or empty they will never be listed;
          if its value begins with ‘list’, they will always be listed;
          if it begins with ‘autolist’ or ‘ambiguous’, they will be
          listed when the ‘AUTO_LIST’ or ‘LIST_AMBIGUOUS’ options
          respectively would normally cause them to be.

          If the substring ‘force’ appears in the value, this makes the
          list be shown even if there is only one match.  Normally, the
          list would be shown only if there are at least two matches.

          The value contains the substring ‘packed’ if the ‘LIST_PACKED’
          option is set.  If this substring is given for all matches
          added to a group, this group will show the ‘LIST_PACKED’
          behavior.  The same is done for the ‘LIST_ROWS_FIRST’ option
          with the substring ‘rows’.

          Finally, if the value contains the string ‘explanations’, only
          the explanation strings, if any, will be listed and if it
          contains ‘messages’, only the messages (added with the ‘-x’
          option of ‘compadd’) will be listed.  If it contains both
          ‘explanations’ and ‘messages’ both kinds of explanation
          strings will be listed.  It will be set appropriately on entry
          to a completion widget and may be changed there.

     ‘list_lines’

          This gives the number of lines that are needed to display the
          full list of completions.  Note that to calculate the total
          number of lines to display you need to add the number of lines
          needed for the command line to this value, this is available
          as the value of the ‘BUFFERLINES’ special parameter.

     ‘list_max’

          Initially this is set to the value of the ‘LISTMAX’ parameter.
          It may be set to any other value; when the widget exits this
          value will be used in the same way as the value of ‘LISTMAX’.

     ‘nmatches’

          The number of matches added by the completion code so far.

     ‘old_insert’

          On entry to the widget this will be set to the number of the
          match of an old list of completions that is currently inserted
          into the command line.  If no match has been inserted, this is
          unset.

          As with ‘old_list’, the value of this key will only be used if
          it is the string ‘keep’.  If it was set to this value by the
          widget and there was an old match inserted into the command
          line, this match will be kept and if the value of the ‘insert’
          key specifies that another match should be inserted, this will
          be inserted after the old one.

     ‘old_list’

          This is set to ‘yes’ if there is still a valid list of
          completions from a previous completion at the time the widget
          is invoked.  This will usually be the case if and only if the
          previous editing operation was a completion widget or one of
          the builtin completion functions.  If there is a valid list
          and it is also currently shown on the screen, the value of
          this key is ‘shown’.

          After the widget has exited the value of this key is only used
          if it was set to ‘keep’.  In this case the completion code
          will continue to use this old list.  If the widget generated
          new matches, they will not be used.

     ‘parameter’

          The name of the parameter when completing in a subscript or in
          the value of a parameter assignment.

     ‘pattern_insert’

          Normally this is set to ‘menu’, which specifies that menu
          completion will be used whenever a set of matches was
          generated using ‘pattern_match’ (see below).  If it is set to
          any other non-empty string by the user and menu completion is
          not selected by other option settings, the code will instead
          insert any common prefix for the generated matches as with
          normal completion.

     ‘pattern_match’

          Locally controls the behaviour given by the ‘GLOB_COMPLETE’
          option.  Initially it is set to ‘*’ if and only if the option
          is set.  The completion widget may set it to this value, to an
          empty string (which has the same effect as unsetting it), or
          to any other non-empty string.  If it is non-empty, unquoted
          metacharacters on the command line will be treated as
          patterns; if it is ‘*’, then additionally a wildcard ‘*’ is
          assumed at the cursor position; if it is empty or unset,
          metacharacters will be treated literally.

          Note that the match specifications given to the ‘compadd’
          builtin command are not used if this is set to a non-empty
          string.

     ‘quote’

          When completing inside quotes, this contains the quotation
          character (i.e.  either a single quote, a double quote, or a
          backtick).  Otherwise it is unset.

     ‘quoting’

          When completing inside single quotes, this is set to the
          string ‘single’; inside double quotes, the string ‘double’;
          inside backticks, the string ‘backtick’.  Otherwise it is
          unset.

     ‘redirect’

          The redirection operator when completing in a redirection
          position, i.e.  one of ‘<’, ‘>’, etc.

     ‘restore’

          This is set to ‘auto’ before a function is entered, which
          forces the special parameters mentioned above (‘words’,
          ‘CURRENT’, ‘PREFIX’, ‘IPREFIX’, ‘SUFFIX’, and ‘ISUFFIX’) to be
          restored to their previous values when the function exits.  If
          a function unsets it or sets it to any other string, they will
          not be restored.

     ‘to_end’

          Specifies the occasions on which the cursor is moved to the
          end of a string when a match is inserted.  On entry to a
          widget function, it may be ‘single’ if this will happen when a
          single unambiguous match was inserted or ‘match’ if it will
          happen any time a match is inserted (for example, by menu
          completion; this is likely to be the effect of the
          ‘ALWAYS_TO_END’ option).

          On exit, it may be set to ‘single’ as above.  It may also be
          set to ‘always’, or to the empty string or unset; in those
          cases the cursor will be moved to the end of the string always
          or never respectively.  Any other string is treated as
          ‘match’.

     ‘unambiguous’

          This key is read-only and will always be set to the common
          (unambiguous) prefix the completion code has generated for all
          matches added so far.

     ‘unambiguous_cursor’

          This gives the position the cursor would be placed at if the
          common prefix in the ‘unambiguous’ key were inserted, relative
          to the value of that key.  The cursor would be placed before
          the character whose index is given by this key.

     ‘unambiguous_positions’

          This contains all positions where characters in the
          unambiguous string are missing or where the character inserted
          differs from at least one of the matches.  The positions are
          given as indexes into the string given by the value of the
          ‘unambiguous’ key.

     ‘vared’

          If completion is called while editing a line using the ‘vared’
          builtin, the value of this key is set to the name of the
          parameter given as an argument to ‘vared’.  This key is only
          set while a ‘vared’ command is active.

‘words’

     This array contains the words present on the command line currently
     being edited.


File: zsh.info,  Node: Completion Builtin Commands,  Next: Completion Condition Codes,  Prev: Completion Special Parameters,  Up: Completion Widgets

18.3 Completion Builtin Commands
================================

‘compadd’ [ ‘-akqQfenUl12C’ ] [ ‘-F’ ARRAY ]

          ‘[-P’ PREFIX ] [ ‘-S’ SUFFIX ]

          ‘[-p’ HIDDEN-PREFIX ] [ ‘-s’ HIDDEN-SUFFIX ]

          ‘[-i’ IGNORED-PREFIX ] [ ‘-I’ IGNORED-SUFFIX ]

          ‘[-W’ FILE-PREFIX ] [ ‘-d’ ARRAY ]

          ‘[-J’ GROUP-NAME ] [ ‘-X’ EXPLANATION ] [ ‘-x’ MESSAGE ]

          ‘[-V’ GROUP-NAME ] [ ‘-o’ [ ORDER ] ]

          ‘[-r’ REMOVE-CHARS ] [ ‘-R’ REMOVE-FUNC ]

          ‘[-D’ ARRAY ] [ ‘-O’ ARRAY ] [ ‘-A’ ARRAY ]

          ‘[-E’ NUMBER ]

          ‘[-M’ MATCH-SPEC ] [ ‘--’ ] [ COMPLETIONS … ]

     This builtin command can be used to add matches directly and
     control all the information the completion code stores with each
     possible completion.  The return status is zero if at least one
     match was added and non-zero if no matches were added.

     The completion code breaks each match into seven fields in the
     order:

          <IPRE><APRE><HPRE><BODY><HSUF><ASUF><ISUF>

     The first field is an ignored prefix taken from the command line,
     the contents of the ‘IPREFIX’ parameter plus the string given with
     the ‘-i’ option.  With the ‘-U’ option, only the string from the
     ‘-i’ option is used.  The field <APRE> is an optional prefix string
     given with the ‘-P’ option.  The <HPRE> field is a string that is
     considered part of the match but that should not be shown when
     listing completions, given with the ‘-p’ option; for example,
     functions that do filename generation might specify a common path
     prefix this way.  <BODY> is the part of the match that should
     appear in the list of matches shown to the user.  The suffixes
     <HSUF>, <ASUF> and <ISUF> correspond to the prefixes <HPRE>, <APRE>
     and <IPRE> and are given by the options ‘-s’, ‘-S’ and ‘-I’,
     respectively.

     The supported flags are:

     ‘-P’ PREFIX

          This gives a string to be inserted before each match.  The
          string given is not considered as part of the match and any
          shell metacharacters in it will not be quoted when the string
          is inserted.

     ‘-S’ SUFFIX

          Like ‘-P’, but gives a string to be inserted after each match.

     ‘-p’ HIDDEN-PREFIX

          This gives a string that should be inserted before each match
          but that should not appear in the list of matches.  Unless the
          ‘-U’ option is given, this string must be matched as part of
          the string on the command line.

     ‘-s’ HIDDEN-SUFFIX

          Like ‘-p’, but gives a string to insert after each match.

     ‘-i’ IGNORED-PREFIX

          This gives a string to insert just before any string given
          with the ‘-P’ option.  Without ‘-P’ the string is inserted
          before the string given with ‘-p’ or directly before each
          match.

     ‘-I’ IGNORED-SUFFIX

          Like ‘-i’, but gives an ignored suffix.

     ‘-a’

          With this flag the COMPLETIONS are taken as names of arrays
          and the actual completions are their values.  If only some
          elements of the arrays are needed, the COMPLETIONS may also
          contain subscripts, as in ‘foo[2,-1]’.

     ‘-k’

          With this flag the COMPLETIONS are taken as names of
          associative arrays and the actual completions are their keys.
          As for ‘-a’, the WORDS may also contain subscripts, as in
          ‘foo[(R)*bar*]’.

     ‘-d’ ARRAY

          This adds per-completion display strings.  The ARRAY should
          contain one element per COMPLETION given.  The completion code
          will then display the first element instead of the first
          COMPLETION, and so on.  The ARRAY may be given as the name of
          an array parameter, or directly as a literal array enclosed in
          parentheses.  A literal array is a space or comma separated
          list of words; quotes have no special meaning and backslashes
          can be used for escaping (for example, ‘(foo\ bar)’ produces
          one element, ‘foo bar’, while ‘(foo bar)’ produces two
          elements, ‘foo’ and ‘bar’).

          If there are fewer display strings than COMPLETIONS, the
          leftover COMPLETIONS will be displayed unchanged and if there
          are more display strings than COMPLETIONS, the leftover
          display strings will be silently ignored.

     ‘-l’

          This option only has an effect if used together with the ‘-d’
          option.  If it is given, the display strings are listed one
          per line, not arrayed in columns.

     ‘-o’ [ ORDER ]

          This controls the order in which matches are sorted.  ORDER is
          a comma-separated list comprising the following possible
          values.  These values can be abbreviated to their initial two
          or three characters.  Note that the order forms part of the
          group name space so matches with different orderings will not
          be in the same group; additionally, since ordering flags are
          not respected on the default group, a group name must be given
          explicitly.  See ‘-J’ and ‘-V’ below.

          ‘match’

               If given, the order of the output is determined by the
               match strings; otherwise it is determined by the display
               strings (i.e.  the strings given by the ‘-d’ option).
               This is the default if ‘-o’ is specified but the ORDER
               argument is omitted.

          ‘nosort’

               This specifies that the COMPLETIONS are pre-sorted and
               their order should be preserved.  This value only makes
               sense alone and cannot be combined with any others.

          ‘numeric’

               If the matches include numbers, sort them numerically
               rather than lexicographically.

          ‘reverse’

               Arrange the matches backwards by reversing the sort
               ordering.

     ‘-J’ GROUP-NAME

          Gives the name of the group that the matches should be stored
          in.

     ‘-V’ GROUP-NAME

          Like ‘-J’ but naming an unsorted group.  This option is
          identical to the combination of ‘-J’ and ‘-o nosort’.

     ‘-1’

          If given together with the ‘-V’ option, makes only consecutive
          duplicates in the group be removed.  If combined with the ‘-J’
          option, this has no visible effect.  Note that groups with and
          without this flag are in different name spaces.

     ‘-2’

          If given together with the ‘-J’ or ‘-V’ option, makes all
          duplicates be kept.  Again, groups with and without this flag
          are in different name spaces.

     ‘-X’ EXPLANATION

          The EXPLANATION string will be printed with the list of
          matches, above the group currently selected.

          Within the EXPLANATION, the following sequences may be used to
          specify output attributes as described in *note Expansion of
          Prompt Sequences: e8.: ‘%B’, ‘%S’, ‘%U’, ‘%F’, ‘%K’ and their
          lower case counterparts, as well as ‘%H’ and ‘%{...%}’.  ‘%F’,
          ‘%K’, ‘%H’ and ‘%{...%}’ take arguments in the same form as
          prompt expansion.  (Note that the sequence ‘%G’ is not
          available; an argument to ‘%{’ should be used instead.)  The
          sequence ‘%%’ produces a literal ‘%’.

          These sequences are most often employed by users when
          customising the ‘format’ style (see *note Standard Styles:
          e9.), but they must also be taken into account when writing
          completion functions, as passing descriptions with unescaped
          ‘%’ characters to utility functions such as ‘_arguments’ and
          ‘_message’ may produce unexpected results.  If arbitrary text
          is to be passed in a description, it can be escaped using e.g.
          ‘${my_str//\%/%%}’.

     ‘-x’ MESSAGE

          Like ‘-X’, but the MESSAGE will be printed even if there are
          no matches in the group.

     ‘-q’

          The suffix given with ‘-S’ will be automatically removed if
          the next character typed is a blank or does not insert
          anything, or if the suffix consists of only one character and
          the next character typed is the same character.

     ‘-r’ REMOVE-CHARS

          This is a more versatile form of the ‘-q’ option.  The suffix
          given with ‘-S’ or the slash automatically added after
          completing directories will be automatically removed if the
          next character typed inserts one of the characters given in
          the REMOVE-CHARS.  This string is parsed as a characters class
          and understands the backslash sequences used by the ‘print’
          command.  For example, ‘-r "a-z\t"’ removes the suffix if the
          next character typed inserts a lower case character or a TAB,
          and ‘-r "^0-9"’ removes the suffix if the next character typed
          inserts anything but a digit.  One extra backslash sequence is
          understood in this string: ‘\-’ stands for all characters that
          insert nothing.  Thus ‘-S "=" -q’ is the same as ‘-S "=" -r "=
          \t\n\-"’.

          This option may also be used without the ‘-S’ option; then any
          automatically added space will be removed when one of the
          characters in the list is typed.

     ‘-R’ REMOVE-FUNC

          This is another form of the ‘-r’ option.  When a match has
          been accepted and a suffix has been inserted, the function
          REMOVE-FUNC will be called after the next character typed.  It
          is passed the length of the suffix as an argument and can use
          the special parameters available in ordinary (non-completion)
          zle widgets (see *note User-Defined Widgets: da. ) to analyse
          and modify the command line.

     ‘-f’

          If this flag is given, all of the matches built from the
          COMPLETIONS are marked as being the names of files.  They are
          not required to be actual filenames, but if they are, and the
          option ‘LIST_TYPES’ is set, the characters describing the
          types of the files in the completion lists will be shown.
          This also forces a slash to be added when the name of a
          directory is completed.

     ‘-e’

          This flag can be used to tell the completion code that the
          matches added are parameter names for a parameter expansion.
          This will make the ‘AUTO_PARAM_SLASH’ and ‘AUTO_PARAM_KEYS’
          options be used for the matches.

     ‘-W’ FILE-PREFIX

          This string is a pathname that will be prepended to each match
          together with any prefix specified by the ‘-p’ option to form
          a complete filename for testing.  Hence it is only useful if
          combined with the ‘-f’ flag, as the tests will not otherwise
          be performed.

     ‘-F’ ARRAY

          Specifies an array containing patterns.  COMPLETIONS that
          match one of these patterns are ignored, that is, not
          considered to be matches.

          The ARRAY may be the name of an array parameter or a list of
          literal patterns enclosed in parentheses and quoted, as in ‘-F
          "(*?.o *?.h)"’.  If the name of an array is given, the
          elements of the array are taken as the patterns.

     ‘-Q’

          This flag instructs the completion code not to quote any
          metacharacters in the matches when inserting them into the
          command line.

     ‘-M’ MATCH-SPEC

          This gives local match specifications as described below in
          Completion Matching Control.  This option may be given more
          than once.  In this case all MATCH-SPECs given are
          concatenated with spaces between them to form the
          specification string to use.  Note that they will only be used
          if the ‘-U’ option is not given.

     ‘-n’

          Specifies that matching COMPLETIONS are to be added to the set
          of matches, but are not to be listed to the user.

     ‘-U’

          If this flag is given, all COMPLETIONS are added to the set of
          matches and no matching will be done by the completion code.
          Normally this is used in functions that do the matching
          themselves.

     ‘-O’ ARRAY

          If this option is given, the COMPLETIONS are ‘not’ added to
          the set of matches.  Instead, matching is done as usual and
          all of the COMPLETIONS that match will be stored in the array
          parameter whose name is given as ARRAY.

     ‘-A’ ARRAY

          As the ‘-O’ option, except that instead of those of the
          COMPLETIONS which match being stored in ARRAY, the strings
          generated internally by the completion code are stored.  For
          example, with a match specification of ‘-M "L:|no="’, a
          current word of ‘nof’ and COMPLETIONS of ‘foo’, this option
          stores the string ‘nofoo’ in the array, whereas the ‘-O’
          option stores the ‘foo’ originally given.

     ‘-D’ ARRAY

          As with ‘-O’, the COMPLETIONS are not added to the set of
          matches.  Instead, whenever the Nth COMPLETION does not match,
          the Nth element of the ARRAY is removed.  Elements for which
          the corresponding COMPLETION matches are retained.  This
          option can be used more than once to remove elements from
          multiple arrays.

     ‘-C’

          This option adds a special match which expands to all other
          matches when inserted into the line, even those that are added
          after this option is used.  Together with the ‘-d’ option it
          is possible to specify a string that should be displayed in
          the list for this special match.  If no string is given, it
          will be shown as a string containing the strings that would be
          inserted for the other matches, truncated to the width of the
          screen.

     ‘-E’ NUMBER

          This option adds NUMBER empty matches after matching
          COMPLETIONS have been added.  An empty match takes up space in
          completion listings but will never be inserted in the line and
          can’t be selected with menu completion or menu selection.
          This makes empty matches only useful to format completion
          lists and to make explanatory string be shown in completion
          lists (since empty matches can be given display strings with
          the ‘-d’ option).  And because all but one empty string would
          otherwise be removed, this option implies the ‘-V’ and ‘-2’
          options (even if an explicit ‘-J’ option is given).  This can
          be important to note as it affects the name space into which
          matches are added.

     ‘-’

     ‘--’

          This flag ends the list of flags and options.  All arguments
          after it will be taken as the COMPLETIONS even if they begin
          with hyphens.

     Except for the ‘-M’ flag, if any of these flags is given more than
     once, the first one (and its argument) will be used.

‘compset -p’ NUMBER

‘compset -P’ [ NUMBER ] PATTERN

‘compset -s’ NUMBER

‘compset -S’ [ NUMBER ] PATTERN

‘compset -n’ BEGIN [ END ]

‘compset -N’ BEG-PAT [ END-PAT ]

‘compset -q’

     This command simplifies modification of the special parameters,
     while its return status allows tests on them to be carried out.

     The options are:

     ‘-p’ NUMBER

          If the value of the ‘PREFIX’ parameter is at least NUMBER
          characters long, the first NUMBER characters are removed from
          it and appended to the contents of the ‘IPREFIX’ parameter.

     ‘-P’ [ NUMBER ] PATTERN

          If the value of the ‘PREFIX’ parameter begins with anything
          that matches the PATTERN, the matched portion is removed from
          ‘PREFIX’ and appended to ‘IPREFIX’.

          Without the optional NUMBER, the longest match is taken, but
          if NUMBER is given, anything up to the NUMBERth match is
          moved.  If the NUMBER is negative, the NUMBERth longest match
          is moved.  For example, if ‘PREFIX’ contains the string
          ‘a=b=c’, then ‘compset -P '*\='’ will move the string ‘a=b=’
          into the ‘IPREFIX’ parameter, but ‘compset -P 1 '*\='’ will
          move only the string ‘a=’.

     ‘-s’ NUMBER

          As ‘-p’, but transfer the last NUMBER characters from the
          value of ‘SUFFIX’ to the front of the value of ‘ISUFFIX’.

     ‘-S’ [ NUMBER ] PATTERN

          As ‘-P’, but match the last portion of ‘SUFFIX’ and transfer
          the matched portion to the front of the value of ‘ISUFFIX’.

     ‘-n’ BEGIN [ END ]

          If the current word position as specified by the parameter
          ‘CURRENT’ is greater than or equal to BEGIN, anything up to
          the BEGINth word is removed from the ‘words’ array and the
          value of the parameter ‘CURRENT’ is decremented by BEGIN.

          If the optional END is given, the modification is done only if
          the current word position is also less than or equal to END.
          In this case, the words from position END onwards are also
          removed from the ‘words’ array.

          Both BEGIN and END may be negative to count backwards from the
          last element of the ‘words’ array.

     ‘-N’ BEG-PAT [ END-PAT ]

          If one of the elements of the ‘words’ array before the one at
          the index given by the value of the parameter ‘CURRENT’
          matches the pattern BEG-PAT, all elements up to and including
          the matching one are removed from the ‘words’ array and the
          value of ‘CURRENT’ is changed to point to the same word in the
          changed array.

          If the optional pattern END-PAT is also given, and there is an
          element in the ‘words’ array matching this pattern, the
          parameters are modified only if the index of this word is
          higher than the one given by the ‘CURRENT’ parameter (so that
          the matching word has to be after the cursor).  In this case,
          the words starting with the one matching ‘end-pat’ are also
          removed from the ‘words’ array.  If ‘words’ contains no word
          matching END-PAT, the testing and modification is performed as
          if it were not given.

     ‘-q’

          The word currently being completed is split on spaces into
          separate words, respecting the usual shell quoting
          conventions.  The resulting words are stored in the ‘words’
          array, and ‘CURRENT’, ‘PREFIX’, ‘SUFFIX’, ‘QIPREFIX’, and
          ‘QISUFFIX’ are modified to reflect the word part that is
          completed.

     In all the above cases the return status is zero if the test
     succeeded and the parameters were modified and non-zero otherwise.
     This allows one to use this builtin in tests such as:

           if compset -P '*\='; then ...

     This forces anything up to and including the last equal sign to be
     ignored by the completion code.

‘compcall’ [ ‘-TD’ ]

     This allows the use of completions defined with the ‘compctl’
     builtin from within completion widgets.  The list of matches will
     be generated as if one of the non-widget completion functions
     (‘complete-word’, etc.)  had been called, except that only
     ‘compctl’s given for specific commands are used.  To force the code
     to try completions defined with the ‘-T’ option of ‘compctl’ and/or
     the default completion (whether defined by ‘compctl -D’ or the
     builtin default) in the appropriate places, the ‘-T’ and/or ‘-D’
     flags can be passed to ‘compcall’.

     The return status can be used to test if a matching ‘compctl’
     definition was found.  It is non-zero if a ‘compctl’ was found and
     zero otherwise.

     Note that this builtin is defined by the ‘zsh/compctl’ module.


File: zsh.info,  Node: Completion Condition Codes,  Next: Completion Matching Control,  Prev: Completion Builtin Commands,  Up: Completion Widgets

18.4 Completion Condition Codes
===============================

The following additional condition codes for use within the ‘[[’ … ‘]]’
construct are available in completion widgets.  These work on the
special parameters.  All of these tests can also be performed by the
‘compset’ builtin, but in the case of the condition codes the contents
of the special parameters are not modified.

‘-prefix’ [ NUMBER ] PATTERN

     true if the test for the ‘-P’ option of ‘compset’ would succeed.

‘-suffix’ [ NUMBER ] PATTERN

     true if the test for the ‘-S’ option of ‘compset’ would succeed.

‘-after’ BEG-PAT

     true if the test of the ‘-N’ option with only the BEG-PAT given
     would succeed.

‘-between’ BEG-PAT END-PAT

     true if the test for the ‘-N’ option with both patterns would
     succeed.


File: zsh.info,  Node: Completion Matching Control,  Next: Completion Widget Example,  Prev: Completion Condition Codes,  Up: Completion Widgets

18.5 Completion Matching Control
================================

When the user invokes completion, the current ‘word’ on the command line
(that is, the word the cursor is currently on) is used to generate a
‘match pattern’.  Only those ‘completions’ that match the pattern are
offered to the user as ‘matches’.

The default match pattern is generated from the current word by either

        * appending a ‘*’ (matching any number of characters in a
          completion)

     ‘or,’ * if the shell option ‘COMPLETE_IN_WORD’ is set, inserting a
     ‘*’ at the cursor position.

This narrow pattern can be broadened selectively by passing a ‘match
specification’ to the ‘compadd’ builtin command through its ‘-M’ option
(see *note Completion Builtin Commands: e7.).  A match specification
consists of one or more MATCHERS separated by whitespace.  Matchers in a
match specification are applied one at a time, from left to right.  Once
all matchers have been applied, completions are compared to the final
match pattern and non-matching ones are discarded.

        * Note that the ‘-M’ option is ignored if the current word
          contains a glob

     pattern and the shell option ‘GLOB_COMPLETE’ is set or if the
     ‘pattern_match’ key of the special associative array ‘compstate’ is
     set to a non-empty value (see *note Completion Special Parameters:
     e6.).

        * Users of the

          Completion System

     should generally not use the ‘-M’ option directly, but rather use
     the

     ‘matcher-list’ and ‘matcher’ styles (see *note Standard Styles:
     e9.).

Each matcher consists of

        * a case-sensitive letter

        * a ‘:’,

        * one or more patterns separated by pipes (‘|’),

        * an equals sign (‘=’), and

        * another pattern.

The patterns before the ‘=’ are used to match substrings of the current
word.  For each matched substring, the corresponding part of the match
pattern is broadened with the pattern after the ‘=’, by means of a
logical ‘OR’.

Each pattern in a matcher consists of either

        * the empty string or

        * a sequence of

                  * literal characters (which may be quoted with a ‘\’),

                  * question marks (‘?’),

                  * bracket expressions (‘[...]’; see *note Glob
                    Operators: 7c.),

               and/or * brace expressions (see below).

Other shell patterns are not allowed.

A brace expression, like a bracket expression, consists of a list of

        * literal characters,

        * ranges (‘0-9’), and/or

        * character classes (‘[:’NAME‘:]’).

However, they differ from each other as follows:

        * A brace expression is delimited by a pair of braces (‘{...}’).

        * Brace expressions do not support negations.  That is, an
          initial

     ‘!’ or ‘^’ has no special meaning and will be interpreted as a
     literal character.  * When a character in the current word matches
     the Nth pattern in a brace expression, the corresponding part of
     the match pattern is broadened only with the Nth pattern of the
     brace expression on the other side of the ‘=’, if there is one; if
     there is no brace expression on the other side, then this pattern
     is the empty string.  However, if either brace expression has more
     elements than the other, then the excess entries are simply
     ignored.  When comparing indexes, each literal character or
     character class counts as one element, but each range is instead
     expanded to the full list of literal characters it represents.
     Additionally, if on ‘both’ sides of the ‘=’, the Nth pattern is
     ‘[:upper:]’ or ‘[:lower:]’, then these are expanded as ranges, too.

Note that, although the matching system does not yet handle multibyte
characters, this is likely to be a future extension.  Hence, using
‘[:upper:]’ and ‘[:lower:]’ is recommended over ‘A-Z’ and ‘a-z’.

Below are the different forms of matchers supported.  Each ‘uppercase’
form behaves exactly like its lowercase counterpart, but adds an
additional step ‘after’ the match pattern has filtered out non-matching
completions: Each of a match’s substrings that was matched by a
subpattern from an uppercase matcher is replaced with the corresponding
substring of the current word.  However, patterns from ‘lowercase’
matchers have higher weight: If a substring of the current word was
matched by patterns from both a lowercase and an uppercase matcher, then
the lowercase matcher’s pattern wins and the corresponding part of the
match is not modified.

Unless indicated otherwise, each example listed assumes
‘COMPLETE_IN_WORD’ to be unset (as it is by default).

‘m:’WORD-PAT‘=’MATCH-PAT

‘M:’WORD-PAT‘=’MATCH-PAT

     For each substring of the current word that matches WORD-PAT,
     broaden the corresponding part of the match pattern to additionally
     match MATCH-PAT.

     Examples:

          ‘m:{[:lower:]}={[:upper:]}’ lets any lower case character in
          the current word be completed to itself or its uppercase
          counterpart.  So, the completions ‘foo’, ‘FOO’ and ‘Foo’ will
          are be considered matches for the word ‘fo’.

          ‘M:_=’ inserts every underscore from the current word into
          each match, in the same relative position, determined by
          matching the substrings around it.  So, given a completion
          ‘foo’, the word ‘f_o’ will be completed to the match ‘f_oo’,
          even though the latter was not present as a completion.

‘b:’WORD-PAT‘=’MATCH-PAT

‘B:’WORD-PAT‘=’MATCH-PAT

‘e:’WORD-PAT‘=’MATCH-PAT

‘E:’WORD-PAT‘=’MATCH-PAT

     For each consecutive substring at the ‘b:’eginning or ‘e:’nd of the
     current word that matches WORD-PAT, broaden the corresponding part
     of the match pattern to additionally match MATCH-PAT.

     Examples:

          ‘b:-=+’ lets any number of minuses at the start of the current
          word be completed to a minus or a plus.

          ‘B:0=’ adds all zeroes at the beginning of the current word to
          the beginning of each match.

‘l:|’WORD-PAT‘=’MATCH-PAT

‘L:|’WORD-PAT‘=’MATCH-PAT

‘r:’WORD-PAT‘|=’MATCH-PAT

‘R:’WORD-PAT‘|=’MATCH-PAT

     If there is a substring at the ‘l:’eft or ‘r:’ight edge of the
     current word that matches WORD-PAT, then broaden the corresponding
     part of the match pattern to additionally match MATCH-PAT.

     For each ‘l:’, ‘L:’, ‘r:’ and ‘R:’ matcher (including the ones
     below), the pattern MATCH-PAT may also be a ‘*’.  This matches any
     number of characters in a completion.

     Examples:

          ‘r:|=*’ appends a ‘*’ to the match pattern, even when
          ‘COMPLETE_IN_WORD’ is set and the cursor is not at the end of
          the current word.

          If the current word starts with a minus, then ‘L:|-=’ will
          prepend it to each match.

‘l:’ANCHOR‘|’WORD-PAT‘=’MATCH-PAT

‘L:’ANCHOR‘|’WORD-PAT‘=’MATCH-PAT

‘r:’WORD-PAT‘|’ANCHOR‘=’MATCH-PAT

‘R:’WORD-PAT‘|’ANCHOR‘=’MATCH-PAT

     For each substring of the current word that matches WORD-PAT and
     has on its ‘l:’eft or ‘r:’ight another substring matching ANCHOR,
     broaden the corresponding part of the match pattern to additionally
     match MATCH-PAT.

     Note that these matchers (and the ones below) modify only what is
     matched by WORD-PAT; they do not change the matching behavior of
     what is matched by ANCHOR (or COANCHOR; see the matchers below).
     Thus, unless its corresponding part of the match pattern has been
     modified, the anchor in the current word has to match literally in
     each completion, just like any other substring of the current word.

     If a matcher includes at least one anchor (which includes the
     matchers with two anchors, below), then MATCH-PAT may also be ‘*’
     or ‘**’.  ‘*’ can match any part of a completion that does not
     contain any substrings matching ANCHOR, whereas a ‘**’ can match
     any part of a completion, period.  (Note that this is different
     from the behavior of ‘*’ in the anchorless forms of ‘l:’ and ‘r:’
     and also different from ‘*’ and ‘**’ in glob expressions.)

     Examples:

          ‘r:|.=*’ makes the completion ‘comp.sources.unix’ a match for
          the word ‘..u’ – but ‘not’ for the word ‘.u’.

          Given a completion ‘--foo’, the matcher ‘L:--|no-=’ will
          complete the word ‘--no-’ to the match ‘--no-foo’.

‘l:’ANCHOR‘||’COANCHOR‘=’MATCH-PAT

‘L:’ANCHOR‘||’COANCHOR‘=’MATCH-PAT

‘r:’COANCHOR‘||’ANCHOR‘=’MATCH-PAT

‘R:’COANCHOR‘||’ANCHOR‘=’MATCH-PAT

     For any two consecutive substrings of the current word that match
     ANCHOR and COANCHOR, in the order given, insert the pattern
     MATCH-PAT between their corresponding parts in the match pattern.

     Note that, unlike ANCHOR, the pattern COANCHOR does not change what
     ‘*’ can match.

     Examples:

          ‘r:?||[[:upper:]]=*’ will complete the current word ‘fB’ to
          ‘fooBar’, but it will not complete it to ‘fooHooBar’ (because
          ‘*’ here cannot match anything that includes a match for
          ‘`[[:upper:]]’), nor will it complete ‘B’ to ‘fooBar’ (because
          there is no character in the current word to match COANCHOR).

          Given the current word ‘pass.n’ and a completion
          ‘pass.byname’, the matcher ‘L:.||[[:alpha:]]=by’ will produce
          the match ‘pass.name’.

‘x:’

     Ignore this matcher and all matchers to its right.

     This matcher is used to mark the end of a match specification.  In
     a single standalone list of matchers, this has no use, but where
     match specifications are concatenated, as is often the case when
     using the

     Completion System

     , it can allow one match specification to override another.


File: zsh.info,  Node: Completion Widget Example,  Prev: Completion Matching Control,  Up: Completion Widgets

18.6 Completion Widget Example
==============================

The first step is to define the widget:

      zle -C complete complete-word complete-files

Then the widget can be bound to a key using the ‘bindkey’ builtin
command:

      bindkey '^X\t' complete

After that the shell function ‘complete-files’ will be invoked after
typing control-X and TAB. The function should then generate the matches,
e.g.:

      complete-files () { compadd - * }

This function will complete files in the current directory matching the
current word.


File: zsh.info,  Node: Completion System,  Next: Completion Using compctl,  Prev: Completion Widgets,  Up: Top

19 Completion System
********************

* Menu:

* Description: Description<5>.
* Initialization::
* Completion System Configuration::
* Control Functions::
* Bindable Commands::
* Utility Functions::
* Completion System Variables::
* Completion Directories::


File: zsh.info,  Node: Description<5>,  Next: Initialization,  Up: Completion System

19.1 Description
================

This describes the shell code for the ‘new’ completion system, referred
to as ‘compsys’.  It is written in shell functions based on the features
described in

the previous chapter, Completion Widgets

.

The features are contextual, sensitive to the point at which completion
is started.  Many completions are already provided.  For this reason, a
user can perform a great many tasks without knowing any details beyond
how to initialize the system, which is described *note Initialization:
f0.

The context that decides what completion is to be performed may be

        * an argument or option position: these describe the position on
          the

     command line at which completion is requested.  For example ‘first
     argument to rmdir, the word being completed names a directory’;

        * a special context, denoting an element in the shell’s syntax.
          For example

     ‘a word in command position’ or ‘an array subscript’.

A full context specification contains other elements, as we shall
describe.

Besides command names and contexts, the system employs two more
concepts, ‘styles’ and ‘tags’.  These provide ways for the user to
configure the system’s behaviour.

Tags play a dual role.  They serve as a classification system for the
matches, typically indicating a class of object that the user may need
to distinguish.  For example, when completing arguments of the ‘ls’
command the user may prefer to try ‘files’ before ‘directories’, so both
of these are tags.  They also appear as the rightmost element in a
context specification.

Styles modify various operations of the completion system, such as
output formatting, but also what kinds of completers are used (and in
what order), or which tags are examined.  Styles may accept arguments
and are manipulated using the ‘zstyle’ command described in *note The
zsh/zutil Module: ca.

In summary, tags describe ‘what’ the completion objects are, and style
‘how’ they are to be completed.  At various points of execution, the
completion system checks what styles and/or tags are defined for the
current context, and uses that to modify its behavior.  The full
description of context handling, which determines how tags and other
elements of the context influence the behaviour of styles, is described
*note Completion System Configuration: f1.

When a completion is requested, a dispatcher function is called; see the
description of ‘_main_complete’ in the list of control functions below.
This dispatcher decides which function should be called to produce the
completions, and calls it.  The result is passed to one or more
‘completers’, functions that implement individual completion strategies:
simple completion, error correction, completion with error correction,
menu selection, etc.

More generally, the shell functions contained in the completion system
are of two types:

        * those beginning ‘comp’ are to be called directly; there are
          only

     a few of these;

        * those beginning ‘_’ are called by the

     completion code.  The shell functions of this set, which implement
     completion behaviour and may be bound to keystrokes, are referred
     to as ‘widgets’.  These proliferate as new completions are
     required.


File: zsh.info,  Node: Initialization,  Next: Completion System Configuration,  Prev: Description<5>,  Up: Completion System

19.2 Initialization
===================

If the system was installed completely, it should be enough to call the
shell function ‘compinit’ from your initialization file; see the next
section.  However, the function ‘compinstall’ can be run by a user to
configure various aspects of the completion system.

Usually, ‘compinstall’ will insert code into ‘.zshrc’, although if that
is not writable it will save it in another file and tell you that file’s
location.  Note that it is up to you to make sure that the lines added
to ‘.zshrc’ are actually run; you may, for example, need to move them to
an earlier place in the file if ‘.zshrc’ usually returns early.  So long
as you keep them all together (including the comment lines at the start
and finish), you can rerun ‘compinstall’ and it will correctly locate
and modify these lines.  Note, however, that any code you add to this
section by hand is likely to be lost if you rerun ‘compinstall’,
although lines using the command ‘zstyle’ should be gracefully handled.

The new code will take effect next time you start the shell, or run
‘.zshrc’ by hand; there is also an option to make them take effect
immediately.  However, if ‘compinstall’ has removed definitions, you
will need to restart the shell to see the changes.

To run ‘compinstall’ you will need to make sure it is in a directory
mentioned in your ‘fpath’ parameter, which should already be the case if
zsh was properly configured as long as your startup files do not remove
the appropriate directories from ‘fpath’.  Then it must be autoloaded
(‘autoload -U compinstall’ is recommended).  You can abort the
installation any time you are being prompted for information, and your
‘.zshrc’ will not be altered at all; changes only take place right at
the end, where you are specifically asked for confirmation.

* Menu:

* Use of compinit::
* Autoloaded Files::
* Functions: Functions<2>.


File: zsh.info,  Node: Use of compinit,  Next: Autoloaded Files,  Up: Initialization

19.2.1 Use of compinit
----------------------

This section describes the use of ‘compinit’ to initialize completion
for the current session when called directly; if you have run
‘compinstall’ it will be called automatically from your ‘.zshrc’.

To initialize the system, the function ‘compinit’ should be in a
directory mentioned in the ‘fpath’ parameter, and should be autoloaded
(‘autoload -U compinit’ is recommended), and then run simply as
‘compinit’.  This will define a few utility functions, arrange for all
the necessary shell functions to be autoloaded, and will then re-define
all widgets that do completion to use the new system.  If you use the
‘menu-select’ widget, which is part of the ‘zsh/complist’ module, you
should make sure that that module is loaded before the call to
‘compinit’ so that that widget is also re-defined.  If completion styles
(see below) are set up to perform expansion as well as completion by
default, and the TAB key is bound to ‘expand-or-complete’, ‘compinit’
will rebind it to ‘complete-word’; this is necessary to use the correct
form of expansion.

Should you need to use the original completion commands, you can still
bind keys to the old widgets by putting a ‘.’ in front of the widget
name, e.g.  ‘.expand-or-complete’.

To speed up the running of ‘compinit’, it can be made to produce a
dumped configuration that will be read in on future invocations; this is
the default, but can be turned off by calling ‘compinit’ with the option
‘-D’.  The dumped file is ‘.zcompdump’ in the same directory as the
startup files (i.e.  ‘$ZDOTDIR’ or ‘$HOME’); alternatively, an explicit
file name can be given by ‘compinit -d’ DUMPFILE.  The next invocation
of ‘compinit’ will read the dumped file instead of performing a full
initialization.

If the number of completion files changes, ‘compinit’ will recognise
this and produce a new dump file.  However, if the name of a function or
the arguments in the first line of a ‘#compdef’ function (as described
below) change, it is easiest to delete the dump file by hand so that
‘compinit’ will re-create it the next time it is run.  The check
performed to see if there are new functions can be omitted by giving the
option ‘-C’.  In this case the dump file will only be created if there
isn’t one already.  Use option ‘-w’ to explain why a dump file isn’t
loaded and/or why it’s regenerated.

The dumping is actually done by another function, ‘compdump’, but you
will only need to run this yourself if you change the configuration
(e.g.  using ‘compdef’) and then want to dump the new one.  The name of
the old dumped file will be remembered for this purpose.

If the parameter ‘_compdir’ is set, ‘compinit’ uses it as a directory
where completion functions can be found; this is only necessary if they
are not already in the function search path.

For security reasons ‘compinit’ also checks if the completion system
would use files not owned by root or by the current user, or files in
directories that are world- or group-writable or that are not owned by
root or by the current user.  If such files or directories are found,
‘compinit’ will ask if the completion system should really be used.  To
avoid these tests and make all files found be used without asking, use
the option ‘-u’, and to make ‘compinit’ silently ignore all insecure
files and directories use the option ‘-i’.  This security check is
skipped entirely when the ‘-C’ option is given, provided the dumpfile
exists.

The security check can be retried at any time by running the function
‘compaudit’.  This is the same check used by ‘compinit’, but when it is
executed directly any changes to ‘fpath’ are made local to the function
so they do not persist.  The directories to be checked may be passed as
arguments; if none are given, ‘compaudit’ uses ‘fpath’ and ‘_compdir’ to
find completion system directories, adding missing ones to ‘fpath’ as
necessary.  To force a check of exactly the directories currently named
in ‘fpath’, set ‘_compdir’ to an empty string before calling ‘compaudit’
or ‘compinit’.

The function ‘bashcompinit’ provides compatibility with bash’s
programmable completion system.  When run it will define the functions,
‘compgen’ and ‘complete’ which correspond to the bash builtins with the
same names.  It will then be possible to use completion specifications
and functions written for bash.


File: zsh.info,  Node: Autoloaded Files,  Next: Functions<2>,  Prev: Use of compinit,  Up: Initialization

19.2.2 Autoloaded Files
-----------------------

The convention for autoloaded functions used in completion is that they
start with an underscore; as already mentioned, the ‘fpath/FPATH’
parameter must contain the directory in which they are stored.  If ‘zsh’
was properly installed on your system, then ‘fpath/FPATH’ automatically
contains the required directories for the standard functions.

For incomplete installations, if ‘compinit’ does not find enough files
beginning with an underscore (fewer than twenty) in the search path, it
will try to find more by adding the directory ‘_compdir’ to the search
path.  If that directory has a subdirectory named ‘Base’, all
subdirectories will be added to the path.  Furthermore, if the
subdirectory ‘Base’ has a subdirectory named ‘Core’, ‘compinit’ will add
all subdirectories of the subdirectories to the path: this allows the
functions to be in the same format as in the ‘zsh’ source distribution.

When ‘compinit’ is run, it searches all such files accessible via
‘fpath/FPATH’ and reads the first line of each of them.  This line
should contain one of the tags described below.  Files whose first line
does not start with one of these tags are not considered to be part of
the completion system and will not be treated specially.

The tags are:

‘#compdef’ NAME … [ ‘-{p|P’} PATTERN … [ ‘-N’ NAME … ] ]

     The file will be made autoloadable and the function defined in it
     will be called when completing NAMEs, each of which is either the
     name of a command whose arguments are to be completed or one of a
     number of special contexts in the form ‘-’CONTEXT‘-’ described
     below.

     Each NAME may also be of the form CMD‘=’SERVICE.  When completing
     the command CMD, the function typically behaves as if the command
     (or special context) SERVICE was being completed instead.  This
     provides a way of altering the behaviour of functions that can
     perform many different completions.  It is implemented by setting
     the parameter ‘$service’ when calling the function; the function
     may choose to interpret this how it wishes, and simpler functions
     will probably ignore it.

     If the ‘#compdef’ line contains one of the options ‘-p’ or ‘-P’,
     the words following are taken to be patterns.  The function will be
     called when completion is attempted for a command or context that
     matches one of the patterns.  The options ‘-p’ and ‘-P’ are used to
     specify patterns to be tried before or after other completions
     respectively.  Hence ‘-P’ may be used to specify default actions.

     The option ‘-N’ is used after a list following ‘-p’ or ‘-P’; it
     specifies that remaining words no longer define patterns.  It is
     possible to toggle between the three options as many times as
     necessary.

‘#compdef -k’ STYLE KEY-SEQUENCE …

     This option creates a widget behaving like the builtin widget STYLE
     and binds it to the given KEY-SEQUENCEs, if any.  The STYLE must be
     one of the builtin widgets that perform completion, namely
     ‘complete-word’, ‘delete-char-or-list’, ‘expand-or-complete’,
     ‘expand-or-complete-prefix’, ‘list-choices’, ‘menu-complete’,
     ‘menu-expand-or-complete’, or ‘reverse-menu-complete’.  If the
     ‘zsh/complist’ module is loaded (see *note The zsh/complist Module:
     f4.) the widget ‘menu-select’ is also available.

     When one of the KEY-SEQUENCEs is typed, the function in the file
     will be invoked to generate the matches.  Note that a key will not
     be re-bound if it already was (that is, was bound to something
     other than ‘undefined-key’).  The widget created has the same name
     as the file and can be bound to any other keys using ‘bindkey’ as
     usual.

‘#compdef -K’ WIDGET-NAME STYLE KEY-SEQUENCE [ NAME STYLE SEQ … ]

     This is similar to ‘-k’ except that only one KEY-SEQUENCE argument
     may be given for each WIDGET-NAME STYLE pair.  However, the entire
     set of three arguments may be repeated with a different set of
     arguments.  Note in particular that the WIDGET-NAME must be
     distinct in each set.  If it does not begin with ‘_’ this will be
     added.  The WIDGET-NAME should not clash with the name of any
     existing widget: names based on the name of the function are most
     useful.  For example,

           #compdef -K _foo_complete complete-word "^X^C" \
             _foo_list list-choices "^X^D"

     (all on one line) defines a widget ‘_foo_complete’ for completion,
     bound to ‘^X^C’, and a widget ‘_foo_list’ for listing, bound to
     ‘^X^D’.

‘#autoload’ [ OPTIONS ]

     Functions with the ‘#autoload’ tag are marked for autoloading but
     are not otherwise treated specially.  Typically they are to be
     called from within one of the completion functions.  Any OPTIONS
     supplied will be passed to the ‘autoload’ builtin; a typical use is
     ‘+X’ to force the function to be loaded immediately.  Note that the
     ‘-U’ and ‘-z’ flags are always added implicitly.

The ‘#’ is part of the tag name and no white space is allowed after it.
The ‘#compdef’ tags use the ‘compdef’ function described below; the main
difference is that the name of the function is supplied implicitly.

The special contexts for which completion functions can be defined are:

‘-array-value-’

     The right hand side of an array-assignment (NAME‘=(’…‘)’)

‘-assign-parameter-’

     The name of a parameter in an assignment, i.e.  on the left hand
     side of an ‘=’

‘-brace-parameter-’

     The name of a parameter expansion within braces (‘${’…‘}’)

‘-command-’

     A word in command position

‘-condition-’

     A word inside a condition (‘[[’…‘]]’)

‘-default-’

     Any word for which no other completion is defined

‘-equal-’

     A word beginning with an equals sign

‘-first-’

     This is tried before any other completion function.  The function
     called may set the ‘_compskip’ parameter to one of various values:
     ‘all’: no further completion is attempted; a string containing the
     substring ‘patterns’: no pattern completion functions will be
     called; a string containing ‘default’: the function for the
     ‘-default-’ context will not be called, but functions defined for
     commands will be.

‘-math-’

     Inside mathematical contexts, such as ‘((’…‘))’

‘-parameter-’

     The name of a parameter expansion (‘$’…)

‘-redirect-’

     The word after a redirection operator.

‘-subscript-’

     The contents of a parameter subscript.

‘-tilde-’

     After an initial tilde (‘~’), but before the first slash in the
     word.

‘-value-’

     On the right hand side of an assignment.

Default implementations are supplied for each of these contexts.  In
most cases the context ‘-’CONTEXT‘-’ is implemented by a corresponding
function ‘_’CONTEXT, for example the context ‘-tilde-’ and the function
‘_tilde’).

The contexts ‘-redirect-’ and ‘-value-’ allow extra context-specific
information.  (Internally, this is handled by the functions for each
context calling the function ‘_dispatch’.)  The extra information is
added separated by commas.

For the ‘-redirect-’ context, the extra information is in the form
‘-redirect-,’OP‘,’COMMAND, where OP is the redirection operator and
COMMAND is the name of the command on the line.  If there is no command
on the line yet, the COMMAND field will be empty.

For the ‘-value-’ context, the form is ‘-value-,’NAME‘,’COMMAND, where
NAME is the name of the parameter on the left hand side of the
assignment.  In the case of elements of an associative array, for
example ‘assoc=(key <TAB>’, NAME is expanded to NAME‘-’KEY.  In certain
special contexts, such as completing after ‘make CFLAGS=’, the COMMAND
part gives the name of the command, here ‘make’; otherwise it is empty.

It is not necessary to define fully specific completions as the
functions provided will try to generate completions by progressively
replacing the elements with ‘-default-’.  For example, when completing
after ‘foo=<TAB>’, ‘_value’ will try the names ‘-value-,foo,’ (note the
empty COMMAND part), ‘-value-,foo,-default-’
andtt(-value-,-default-,-default-), in that order, until it finds a
function to handle the context.

As an example:

      compdef '_files -g "*.log"' '-redirect-,2>,-default-'

completes files matching ‘*.log’ after ‘2> <TAB>’ for any command with
no more specific handler defined.

Also:

      compdef _foo -value-,-default-,-default-

specifies that ‘_foo’ provides completions for the values of parameters
for which no special function has been defined.  This is usually handled
by the function ‘_value’ itself.

The same lookup rules are used when looking up styles (as described
below); for example

      zstyle ':completion:*:*:-redirect-,2>,*:*' file-patterns '*.log'

is another way to make completion after ‘2> <TAB>’ complete files
matching ‘*.log’.


File: zsh.info,  Node: Functions<2>,  Prev: Autoloaded Files,  Up: Initialization

19.2.3 Functions
----------------

The following function is defined by ‘compinit’ and may be called
directly.

‘compdef’ [ ‘-ane’ ] FUNCTION NAME … [ ‘-{p|P’} PATTERN … [ ‘-N’ NAME
…]]

‘compdef -d’ NAME …

‘compdef -k’ [ ‘-an’ ] FUNCTION STYLE KEY-SEQUENCE [ KEY-SEQUENCE … ]

‘compdef -K’ [ ‘-an’ ] FUNCTION NAME STYLE KEY-SEQ [ NAME STYLE SEQ … ]

     The first form defines the FUNCTION to call for completion in the
     given contexts as described for the ‘#compdef’ tag above.

     Alternatively, all the arguments may have the form CMD‘=’SERVICE.
     Here SERVICE should already have been defined by CMD1‘=’SERVICE
     lines in ‘#compdef’ files, as described above.  The argument for
     CMD will be completed in the same way as SERVICE.

     The FUNCTION argument may alternatively be a string containing
     almost any shell code.  If the string contains an equal sign, the
     above will take precedence.  The option ‘-e’ may be used to specify
     the first argument is to be evaluated as shell code even if it
     contains an equal sign.  The string will be executed using the
     ‘eval’ builtin command to generate completions.  This provides a
     way of avoiding having to define a new completion function.  For
     example, to complete files ending in ‘.h’ as arguments to the
     command ‘foo’:

           compdef '_files -g "*.h"' foo

     The option ‘-n’ prevents any completions already defined for the
     command or context from being overwritten.

     The option ‘-d’ deletes any completion defined for the command or
     contexts listed.

     The NAMEs may also contain ‘-p’, ‘-P’ and ‘-N’ options as described
     for the ‘#compdef’ tag.  The effect on the argument list is
     identical, switching between definitions of patterns tried
     initially, patterns tried finally, and normal commands and
     contexts.

     The parameter ‘$_compskip’ may be set by any function defined for a
     pattern context.  If it is set to a value containing the substring
     ‘patterns’ none of the pattern-functions will be called; if it is
     set to a value containing the substring ‘all’, no other function
     will be called.  Setting ‘$_compskip’ in this manner is of
     particular utility when using the ‘-p’ option, as otherwise the
     dispatcher will move on to additional functions (likely the default
     one) after calling the pattern-context one, which can mangle the
     display of completion possibilities if not handled properly.

     The form with ‘-k’ defines a widget with the same name as the
     FUNCTION that will be called for each of the KEY-SEQUENCEs; this is
     like the ‘#compdef -k’ tag.  The function should generate the
     completions needed and will otherwise behave like the builtin
     widget whose name is given as the STYLE argument.  The widgets
     usable for this are: ‘complete-word’, ‘delete-char-or-list’,
     ‘expand-or-complete’, ‘expand-or-complete-prefix’, ‘list-choices’,
     ‘menu-complete’, ‘menu-expand-or-complete’, and
     ‘reverse-menu-complete’, as well as ‘menu-select’ if the
     ‘zsh/complist’ module is loaded.  The option ‘-n’ prevents the key
     being bound if it is already to bound to something other than
     ‘undefined-key’.

     The form with ‘-K’ is similar and defines multiple widgets based on
     the same FUNCTION, each of which requires the set of three
     arguments NAME, STYLE and KEY-SEQuence, where the latter two are as
     for ‘-k’ and the first must be a unique widget name beginning with
     an underscore.

     Wherever applicable, the ‘-a’ option makes the FUNCTION
     autoloadable, equivalent to ‘autoload -U’ FUNCTION.

The function ‘compdef’ can be used to associate existing completion
functions with new commands.  For example,

      compdef _pids foo

uses the function ‘_pids’ to complete process IDs for the command ‘foo’.

Note also the ‘_gnu_generic’ function described below, which can be used
to complete options for commands that understand the ‘--help’ option.


File: zsh.info,  Node: Completion System Configuration,  Next: Control Functions,  Prev: Initialization,  Up: Completion System

19.3 Completion System Configuration
====================================

This section gives a short overview of how the completion system works,
and then more detail on how users can configure how and when matches are
generated.

* Menu:

* Overview: Overview<2>.
* Standard Tags::
* Standard Styles::


File: zsh.info,  Node: Overview<2>,  Next: Standard Tags,  Up: Completion System Configuration

19.3.1 Overview
---------------

When completion is attempted somewhere on the command line the
completion system begins building the context.  The context represents
everything that the shell knows about the meaning of the command line
and the significance of the cursor position.  This takes account of a
number of things including the command word (such as ‘grep’ or ‘zsh’)
and options to which the current word may be an argument (such as the
‘-o’ option to ‘zsh’ which takes a shell option as an argument).

The context starts out very generic (“we are beginning a completion”)
and becomes more specific as more is learned (“the current word is in a
position that is usually a command name” or “the current word might be a
variable name” and so on).  Therefore the context will vary during the
same call to the completion system.

This context information is condensed into a string consisting of
multiple fields separated by colons, referred to simply as ‘the context’
in the remainder of the documentation.  Note that a user of the
completion system rarely needs to compose a context string, unless for
example a new function is being written to perform completion for a new
command.  What a user may need to do is compose a ‘style’ pattern, which
is matched against a context when needed to look up context-sensitive
options that configure the completion system.

The next few paragraphs explain how a context is composed within the
completion function suite.  Following that is discussion of how ‘styles’
are defined.  Styles determine such things as how the matches are
generated, similarly to shell options but with much more control.  They
are defined with the ‘zstyle’ builtin command (see *note The zsh/zutil
Module: ca.).

The context string always consists of a fixed set of fields, separated
by colons and with a leading colon before the first.  Fields which are
not yet known are left empty, but the surrounding colons appear anyway.
The fields are always in the order
‘:completion:’FUNCTION‘:’COMPLETER‘:’COMMAND‘:’ARGUMENT‘:’TAG.  These
have the following meaning:

        * The literal string ‘completion’, saying that this style is
          used by

     the completion system.  This distinguishes the context from those
     used by, for example, zle widgets and ZFTP functions.

        * The FUNCTION, if completion is called from a named widget
          rather

     than through the normal completion system.  Typically this is
     blank, but it is set by special widgets such as ‘predict-on’ and
     the various functions in the ‘Widget’ directory of the distribution
     to the name of that function, often in an abbreviated form.

        * The COMPLETER currently active, the name of the function
          without the

     leading underscore and with other underscores converted to hyphens.
     A ‘completer’ is in overall control of how completion is to be
     performed; ‘complete’ is the simplest, but other completers exist
     to perform related tasks such as correction, or to modify the
     behaviour of a later completer.  See *note Control Functions: f7.
     for more information.

        * The COMMAND or a special ‘-’CONTEXT‘-’, just at it appears

     following the ‘#compdef’ tag or the ‘compdef’ function.  Completion
     functions for commands that have sub-commands usually modify this
     field to contain the name of the command followed by a minus sign
     and the sub-command.  For example, the completion function for the
     ‘cvs’ command sets this field to ‘cvs-add’ when completing
     arguments to the ‘add’ subcommand.

        * The ARGUMENT; this indicates which command line or option
          argument

     we are completing.  For command arguments this generally takes the
     form ‘argument-’N, where N is the number of the argument, and for
     arguments to options the form ‘option-’OPT‘-’N where N is the
     number of the argument to option OPT.  However, this is only the
     case if the command line is parsed with standard UNIX-style options
     and arguments, so many completions do not set this.

        * The TAG.  As described previously, tags are used to
          discriminate between

     the types of matches a completion function can generate in a
     certain context.  Any completion function may use any tag name it
     likes, but a list of the more common ones is given below.

The context is gradually put together as the functions are executed,
starting with the main entry point, which adds ‘:completion:’ and the
FUNCTION element if necessary.  The completer then adds the COMPLETER
element.  The contextual completion adds the COMMAND and ARGUMENT
options.  Finally, the TAG is added when the types of completion are
known.  For example, the context name

      :completion::complete:dvips:option-o-1:files

says that normal completion was attempted as the first argument to the
option ‘-o’ of the command ‘dvips’:

      dvips -o ...

and the completion function will generate filenames.

Usually completion will be tried for all possible tags in an order given
by the completion function.  However, this can be altered by using the
‘tag-order’ style.  Completion is then restricted to the list of given
tags in the given order.

The ‘_complete_help’ bindable command shows all the contexts and tags
available for completion at a particular point.  This provides an easy
way of finding information for ‘tag-order’ and other styles.  It is
described in *note Bindable Commands: f8.

When looking up styles the completion system uses full context names,
including the tag.  Looking up the value of a style therefore consists
of two things: the context, which is matched to the most specific (best
fitting) pattern, and the name of the style itself, which must be
matched exactly.  The following examples demonstrate that patterns may
be loosely defined for styles that apply broadly, or as tightly defined
as desired for styles that apply in narrower circumstances.

For example, many completion functions can generate matches in a simple
and a verbose form and use the ‘verbose’ style to decide which form
should be used.  To make all such functions use the verbose form, put

      zstyle ':completion:*' verbose yes

in a startup file (probably ‘.zshrc’).  This gives the ‘verbose’ style
the value ‘yes’ in every context inside the completion system, unless
that context has a more specific definition.  It is best to avoid giving
the pattern as ‘*’ in case the style has some meaning outside the
completion system.

Many such general purpose styles can be configured simply by using the
‘compinstall’ function.

A more specific example of the use of the ‘verbose’ style is by the
completion for the ‘kill’ builtin.  If the style is set, the builtin
lists full job texts and process command lines; otherwise it shows the
bare job numbers and PIDs.  To turn the style off for this use only:

      zstyle ':completion:*:*:kill:*:*' verbose no

For even more control, the style can use one of the tags ‘jobs’ or
‘processes’.  To turn off verbose display only for jobs:

      zstyle ':completion:*:*:kill:*:jobs' verbose no

The ‘-e’ option to ‘zstyle’ even allows completion function code to
appear as the argument to a style; this requires some understanding of
the internals of completion functions (see ‘zshcompwid’).  For example,

      zstyle -e ':completion:*' hosts 'reply=($myhosts)'

This forces the value of the ‘hosts’ style to be read from the variable
‘myhosts’ each time a host name is needed; this is useful if the value
of ‘myhosts’ can change dynamically.  For another useful example, see
the example in the description of the ‘file-list’ style below.  This
form can be slow and should be avoided for commonly examined styles such
as ‘menu’ and ‘list-rows-first’.

Note that the order in which styles are ‘defined’ does not matter; the
style mechanism uses the most specific possible match for a particular
style to determine the set of values.  Strings are preferred over
patterns (for example, ‘:completion::complete:::foo’ is more specific
than ‘:completion::complete:::*’), and longer patterns are preferred
over the pattern ‘*’.  See *note The zsh/zutil Module: ca. for details.

Context patterns that use something other than a wildcard (‘*’) to match
the middle parts of the context – the COMPLETER, COMMAND, and ARGUMENT
in ‘:completion:’FUNCTION‘:’COMPLETER‘:’COMMAND‘:’ARGUMENT‘:’TAG –
should include all six colons (‘:’) explicitly.  Without this, a pattern
such as ‘:completion:*:foo:*’ could match ‘foo’ against a component
other than the intended one (for example, against COMPLETER when a match
against COMMAND was intended).

Style names like those of tags are arbitrary and depend on the
completion function.  However, the following two sections list some of
the most common tags and styles.


File: zsh.info,  Node: Standard Tags,  Next: Standard Styles,  Prev: Overview<2>,  Up: Completion System Configuration

19.3.2 Standard Tags
--------------------

Some of the following are only used when looking up particular styles
and do not refer to a type of match.

‘accounts’

     used to look up the ‘users-hosts’ style

‘all-expansions’

     used by the ‘_expand’ completer when adding the single string
     containing all possible expansions

‘all-files’

     for the names of all files (as distinct from a particular subset,
     see the ‘globbed-files’ tag).

‘arguments’

     for arguments to a command

‘arrays’

     for names of array parameters

‘association-keys’

     for keys of associative arrays; used when completing inside a
     subscript to a parameter of this type

‘bookmarks’

     when completing bookmarks (e.g.  for URLs and the ‘zftp’ function
     suite)

‘builtins’

     for names of builtin commands

‘characters’

     for single characters in arguments of commands such as ‘stty’.
     Also used when completing character classes after an opening
     bracket

‘colormapids’

     for X colormap ids

‘colors’

     for color names

‘commands’

     for names of external commands.  Also used by complex commands such
     as ‘cvs’ when completing names of subcommands.

‘contexts’

     for contexts in arguments to the ‘zstyle’ builtin command

‘corrections’

     used by the ‘_approximate’ and ‘_correct’ completers for possible
     corrections

‘cursors’

     for cursor names used by X programs

‘default’

     used in some contexts to provide a way of supplying a default when
     more specific tags are also valid.  Note that this tag is used when
     only the FUNCTION field of the context name is set

‘descriptions’

     used when looking up the value of the ‘format’ style to generate
     descriptions for types of matches

‘devices’

     for names of device special files

‘directories’

     for names of directories – ‘local-directories’ is used instead when
     completing arguments of ‘cd’ and related builtin commands when the
     ‘cdpath’ array is set

‘directory-stack’

     for entries in the directory stack

‘displays’

     for X display names

‘domains’

     for network domains

‘email-’PLUGIN

     for email addresses from the ‘_email-’PLUGIN backend of
     ‘_email_addresses’

‘expansions’

     used by the ‘_expand’ completer for individual words (as opposed to
     the complete set of expansions) resulting from the expansion of a
     word on the command line

‘extensions’

     for X server extensions

‘file-descriptors’

     for numbers of open file descriptors

‘files’

     the generic file-matching tag used by functions completing
     filenames

‘fonts’

     for X font names

‘fstypes’

     for file system types (e.g.  for the ‘mount’ command)

‘functions’

     names of functions – normally shell functions, although certain
     commands may understand other kinds of function

‘globbed-files’

     for filenames when the name has been generated by pattern matching

‘groups’

     for names of user groups

‘history-words’

     for words from the history

‘hosts’

     for hostnames

‘indexes’

     for array indexes

‘interfaces’

     for network interfaces

‘jobs’

     for jobs (as listed by the ‘jobs’ builtin)

‘keymaps’

     for names of zsh keymaps

‘keysyms’

     for names of X keysyms

‘libraries’

     for names of system libraries

‘limits’

     for system limits

‘local-directories’

     for names of directories that are subdirectories of the current
     working directory when completing arguments of ‘cd’ and related
     builtin commands (compare ‘path-directories’) – when the ‘cdpath’
     array is unset, ‘directories’ is used instead

‘mailboxes’

     for e-mail folders

‘manuals’

     for names of manual pages

‘maps’

     for map names (e.g.  NIS maps)

‘messages’

     used to look up the ‘format’ style for messages

‘modifiers’

     for names of X modifiers

‘modules’

     for modules (e.g.  ‘zsh’ modules)

‘my-accounts’

     used to look up the ‘users-hosts’ style

‘named-directories’

     for named directories (you wouldn’t have guessed that, would you?)

‘names’

     for all kinds of names

‘newsgroups’

     for USENET groups

‘nicknames’

     for nicknames of NIS maps

‘options’

     for command options

‘original’

     used by the ‘_approximate’, ‘_correct’ and ‘_expand’ completers
     when offering the original string as a match

‘other-accounts’

     used to look up the ‘users-hosts’ style

‘packages’

     for packages (e.g.  ‘rpm’ or installed ‘Debian’ packages)

‘parameters’

     for names of parameters

‘path-directories’

     for names of directories found by searching the ‘cdpath’ array when
     completing arguments of ‘cd’ and related builtin commands (compare
     ‘local-directories’)

‘paths’

     used to look up the values of the ‘expand’, ‘ambiguous’ and
     ‘special-dirs’ styles

‘pods’

     for perl pods (documentation files)

‘ports’

     for communication ports

‘prefixes’

     for prefixes (like those of a URL)

‘printers’

     for print queue names

‘processes’

     for process identifiers

‘processes-names’

     used to look up the ‘command’ style when generating the names of
     processes for ‘killall’

‘sequences’

     for sequences (e.g.  ‘mh’ sequences)

‘sessions’

     for sessions in the ‘zftp’ function suite

‘signals’

     for signal names

‘strings’

     for strings (e.g.  the replacement strings for the ‘cd’ builtin
     command)

‘styles’

     for styles used by the zstyle builtin command

‘suffixes’

     for filename extensions

‘tags’

     for tags (e.g.  ‘rpm’ tags)

‘targets’

     for makefile targets

‘time-zones’

     for time zones (e.g.  when setting the ‘TZ’ parameter)

‘types’

     for types of whatever (e.g.  address types for the ‘xhost’ command)

‘urls’

     used to look up the ‘urls’ and ‘local’ styles when completing URLs

‘users’

     for usernames

‘values’

     for one of a set of values in certain lists

‘variant’

     used by ‘_pick_variant’ to look up the command to run when
     determining what program is installed for a particular command
     name.

‘visuals’

     for X visuals

‘warnings’

     used to look up the ‘format’ style for warnings

‘widgets’

     for zsh widget names

‘windows’

     for IDs of X windows

‘zsh-options’

     for shell options


File: zsh.info,  Node: Standard Styles,  Prev: Standard Tags,  Up: Completion System Configuration

19.3.3 Standard Styles
----------------------

Note that the values of several of these styles represent boolean
values.  Any of the strings ‘true’, ‘on’, ‘yes’, and ‘1’ can be used for
the value ‘true’ and any of the strings ‘false’, ‘off’, ‘no’, and ‘0’
for the value ‘false’.  The behavior for any other value is undefined
except where explicitly mentioned.  The default value may be either
‘true’ or ‘false’ if the style is not set.

Some of these styles are tested first for every possible tag
corresponding to a type of match, and if no style was found, for the
‘default’ tag.  The most notable styles of this type are ‘menu’,
‘list-colors’ and styles controlling completion listing such as
‘list-packed’ and ‘last-prompt’.  When tested for the ‘default’ tag,
only the FUNCTION field of the context will be set so that a style using
the ‘default’ tag will normally be defined along the lines of:

      zstyle ':completion:*:default' menu ...

‘accept-exact’

     This is tested for the ‘default’ tag in addition to the tags valid
     for the current context.  If it is set to ‘true’ and any of the
     trial matches is the same as the string on the command line, this
     match will immediately be accepted (even if it would otherwise be
     considered ambiguous).

     When completing pathnames (where the tag used is ‘paths’) this
     style accepts any number of patterns as the value in addition to
     the boolean values.  Pathnames matching one of these patterns will
     be accepted immediately even if the command line contains some more
     partially typed pathname components and these match no file under
     the directory accepted.

     This style is also used by the ‘_expand’ completer to decide if
     words beginning with a tilde or parameter expansion should be
     expanded.  For example, if there are parameters ‘foo’ and ‘foobar’,
     the string ‘$foo’ will only be expanded if ‘accept-exact’ is set to
     ‘true’; otherwise the completion system will be allowed to complete
     ‘$foo’ to ‘$foobar’.  If the style is set to ‘continue’, ‘_expand’
     will add the expansion as a match and the completion system will
     also be allowed to continue.

‘accept-exact-dirs’

     This is used by filename completion.  Unlike ‘accept-exact’ it is a
     boolean.  By default, filename completion examines all components
     of a path to see if there are completions of that component, even
     if the component matches an existing directory.  For example, when
     completion after ‘/usr/bin/’, the function examines possible
     completions to ‘/usr’.

     When this style is ‘true’, any prefix of a path that matches an
     existing directory is accepted without any attempt to complete it
     further.  Hence, in the given example, the path ‘/usr/bin/’ is
     accepted immediately and completion tried in that directory.

     This style is also useful when completing after directories that
     magically appear when referenced, such as ZFS ‘.zfs’ directories or
     NetApp ‘.snapshot’ directories.  When the style is set the shell
     does not check for the existence of the directory within the parent
     directory.

     If you wish to inhibit this behaviour entirely, set the
     ‘path-completion’ style (see below) to ‘false’.

‘add-space’

     This style is used by the ‘_expand’ completer.  If it is ‘true’
     (the default), a space will be inserted after all words resulting
     from the expansion, or a slash in the case of directory names.  If
     the value is ‘file’, the completer will only add a space to names
     of existing files.  Either a boolean ‘true’ or the value ‘file’ may
     be combined with ‘subst’, in which case the completer will not add
     a space to words generated from the expansion of a substitution of
     the form ‘$(’…‘)’ or ‘${’…‘}’.

     The ‘_prefix’ completer uses this style as a simple boolean value
     to decide if a space should be inserted before the suffix.

‘ambiguous’

     This applies when completing non-final components of filename
     paths, in other words those with a trailing slash.  If it is set,
     the cursor is left after the first ambiguous component, even if
     menu completion is in use.  The style is always tested with the
     ‘paths’ tag.

‘assign-list’

     When completing after an equals sign that is being treated as an
     assignment, the completion system normally completes only one
     filename.  In some cases the value may be a list of filenames
     separated by colons, as with ‘PATH’ and similar parameters.  This
     style can be set to a list of patterns matching the names of such
     parameters.

     The default is to complete lists when the word on the line already
     contains a colon.

‘auto-description’

     If set, this style’s value will be used as the description for
     options that are not described by the completion functions, but
     that have exactly one argument.  The sequence ‘%d’ in the value
     will be replaced by the description for this argument.  Depending
     on personal preferences, it may be useful to set this style to
     something like ‘specify: %d’.  Note that this may not work for some
     commands.

‘avoid-completer’

     This is used by the ‘_all_matches’ completer to decide if the
     string consisting of all matches should be added to the list
     currently being generated.  Its value is a list of names of
     completers.  If any of these is the name of the completer that
     generated the matches in this completion, the string will not be
     added.

     The default value for this style is ‘_expand _oldlist _correct
     _approximate’, i.e.  it contains the completers for which a string
     with all matches will almost never be wanted.

‘cache-path’

     This style defines the path where any cache files containing dumped
     completion data are stored.  It defaults to ‘$ZDOTDIR/.zcompcache’,
     or ‘$HOME/.zcompcache’ if ‘$ZDOTDIR’ is not defined.  The
     completion cache will not be used unless the ‘use-cache’ style is
     set.

‘cache-policy’

     This style defines the function that will be used to determine
     whether a cache needs rebuilding.  See the section on the
     ‘_cache_invalid’ function below.

‘call-command’

     This style is used in the function for commands such as ‘make’ and
     ‘ant’ where calling the command directly to generate matches
     suffers problems such as being slow or, as in the case of ‘make’
     can potentially cause actions in the makefile to be executed.  If
     it is set to ‘true’ the command is called to generate matches.  The
     default value of this style is ‘false’.

‘command’

     In many places, completion functions need to call external commands
     to generate the list of completions.  This style can be used to
     override the command that is called in some such cases.  The
     elements of the value are joined with spaces to form a command line
     to execute.  The value can also start with a hyphen, in which case
     the usual command will be added to the end; this is most useful for
     putting ‘builtin’ or ‘command’ in front to make sure the
     appropriate version of a command is called, for example to avoid
     calling a shell function with the same name as an external command.

     As an example, the completion function for process IDs uses this
     style with the ‘processes’ tag to generate the IDs to complete and
     the list of processes to display (if the ‘verbose’ style is
     ‘true’).  The list produced by the command should look like the
     output of the ‘ps’ command.  The first line is not displayed, but
     is searched for the string ‘PID’ (or ‘pid’) to find the position of
     the process IDs in the following lines.  If the line does not
     contain ‘PID’, the first numbers in each of the other lines are
     taken as the process IDs to complete.

     Note that the completion function generally has to call the
     specified command for each attempt to generate the completion list.
     Hence care should be taken to specify only commands that take a
     short time to run, and in particular to avoid any that may never
     terminate.

‘command-path’

     This is a list of directories to search for commands to complete.
     The default for this style is the value of the special parameter
     ‘path’.

‘commands’

     This is used by the function completing sub-commands for the system
     initialisation scripts (residing in ‘/etc/init.d’ or somewhere not
     too far away from that).  Its values give the default commands to
     complete for those commands for which the completion function isn’t
     able to find them out automatically.  The default for this style
     are the two strings ‘start’ and ‘stop’.

‘complete’

     This is used by the ‘_expand_alias’ function when invoked as a
     bindable command.  If set to ‘true’ and the word on the command
     line is not the name of an alias, matching alias names will be
     completed.

‘complete-options’

     This is used by the completer for ‘cd’, ‘chdir’ and ‘pushd’.  For
     these commands a ‘-’ is used to introduce a directory stack entry
     and completion of these is far more common than completing options.
     Hence unless the value of this style is ‘true’ options will not be
     completed, even after an initial ‘-’.  If it is ‘true’, options
     will be completed after an initial ‘-’ unless there is a preceding
     ‘--’ on the command line.

‘completer’

     The strings given as the value of this style provide the names of
     the completer functions to use.  The available completer functions
     are described in *note Control Functions: f7.

     Each string may be either the name of a completer function or a
     string of the form FUNCTION‘:’NAME.  In the first case the
     COMPLETER field of the context will contain the name of the
     completer without the leading underscore and with all other
     underscores replaced by hyphens.  In the second case the FUNCTION
     is the name of the completer to call, but the context will contain
     the user-defined NAME in the COMPLETER field of the context.  If
     the NAME starts with a hyphen, the string for the context will be
     build from the name of the completer function as in the first case
     with the NAME appended to it.  For example:

           zstyle ':completion:*' completer _complete _complete:-foo

     Here, completion will call the ‘_complete’ completer twice, once
     using ‘complete’ and once using ‘complete-foo’ in the COMPLETER
     field of the context.  Normally, using the same completer more than
     once only makes sense when used with the FUNCTIONS‘:’NAME form,
     because otherwise the context name will be the same in all calls to
     the completer; possible exceptions to this rule are the ‘_ignored’
     and ‘_prefix’ completers.

     The default value for this style is ‘_complete _ignored’: only
     completion will be done, first using the ‘ignored-patterns’ style
     and the ‘$fignore’ array and then without ignoring matches.

‘condition’

     This style is used by the ‘_list’ completer function to decide if
     insertion of matches should be delayed unconditionally.  The
     default is ‘true’.

‘delimiters’

     This style is used when adding a delimiter for use with history
     modifiers or glob qualifiers that have delimited arguments.  It is
     an array of preferred delimiters to add.  Non-special characters
     are preferred as the completion system may otherwise become
     confused.  The default list is ‘:’, ‘+’, ‘/’, ‘-’, ‘%’.  The list
     may be empty to force a delimiter to be typed.

‘disabled’

     If this is set to ‘true’, the ‘_expand_alias’ completer and
     bindable command will try to expand disabled aliases, too.  The
     default is ‘false’.

‘domains’

     A list of names of network domains for completion.  If this is not
     set, domain names will be taken from the file ‘/etc/resolv.conf’.

‘environ’

     The environ style is used when completing for ‘sudo’.  It is set to
     an array of VAR‘=’VALUE assignments to be exported into the local
     environment before the completion for the target command is
     invoked.

           zstyle ':completion:*:sudo::' environ \
             PATH="/sbin:/usr/sbin:$PATH" HOME="/root"

‘expand’

     This style is used when completing strings consisting of multiple
     parts, such as path names.

     If one of its values is the string ‘prefix’, the partially typed
     word from the line will be expanded as far as possible even if
     trailing parts cannot be completed.

     If one of its values is the string ‘suffix’, matching names for
     components after the first ambiguous one will also be added.  This
     means that the resulting string is the longest unambiguous string
     possible.  However, menu completion can be used to cycle through
     all matches.

‘extra-verbose’

     If this style set to ‘true’, the completion listing is still more
     verbose.

     Currently, it is used for ‘commands’ and ‘parameters’ tags.  If it
     is ‘true’ for the ‘commands’ (or ‘parameters’) tag, short
     descriptions of the commands (or the values of the parameters) are
     displayed along with the command (or parameter) names.

‘fake’

     This style may be set for any completion context.  It specifies
     additional strings that will always be completed in that context.
     The form of each string is VALUE‘:’DESCRIPTION; the colon and
     description may be omitted, but any literal colons in VALUE must be
     quoted with a backslash.  Any DESCRIPTION provided is shown
     alongside the value in completion listings.

     It is important to use a sufficiently restrictive context when
     specifying fake strings.  Note that the styles ‘fake-files’ and
     ‘fake-parameters’ provide additional features when completing files
     or parameters.

‘fake-always’

     This works identically to the ‘fake’ style except that the
     ‘ignored-patterns’ style is not applied to it.  This makes it
     possible to override a set of matches completely by setting the
     ignored patterns to ‘*’.

     The following shows a way of supplementing any tag with arbitrary
     data, but having it behave for display purposes like a separate
     tag.  In this example we use the features of the ‘tag-order’ style
     to divide the ‘named-directories’ tag into two when performing
     completion with the standard completer ‘complete’ for arguments of
     ‘cd’.  The tag ‘named-directories-normal’ behaves as normal, but
     the tag ‘named-directories-mine’ contains a fixed set of
     directories.  This has the effect of adding the match group ‘extra
     directories’ with the given completions.

           zstyle ':completion::complete:cd:*' tag-order \
             'named-directories:-mine:extra\ directories
             named-directories:-normal:named\ directories *'
           zstyle ':completion::complete:cd:*:named-directories-mine' \
             fake-always mydir1 mydir2
           zstyle ':completion::complete:cd:*:named-directories-mine' \
             ignored-patterns '*'

‘fake-files’

     This style is used when completing files and looked up without a
     tag.  Its values are of the form DIR‘:’NAMES….  This will add the
     NAMES (strings separated by spaces) as possible matches when
     completing in the directory DIR, even if no such files really
     exist.  The dir may be a pattern; pattern characters or colons in
     DIR should be quoted with a backslash to be treated literally.

     This can be useful on systems that support special file systems
     whose top-level pathnames can not be listed or generated with glob
     patterns (but see ‘accept-exact-dirs’ for a more general way of
     dealing with this problem).  It can also be used for directories
     for which one does not have read permission.

     The pattern form can be used to add a certain ‘magic’ entry to all
     directories on a particular file system.

‘fake-parameters’

     This is used by the completion function for parameter names.  Its
     values are names of parameters that might not yet be set but should
     be completed nonetheless.  Each name may also be followed by a
     colon and a string specifying the type of the parameter (like
     ‘scalar’, ‘array’ or ‘integer’).  If the type is given, the name
     will only be completed if parameters of that type are required in
     the particular context.  Names for which no type is specified will
     always be completed.

‘file-list’

     This style controls whether files completed using the standard
     builtin mechanism are to be listed with a long list similar to ‘ls
     -l’.  Note that this feature uses the shell module ‘zsh/stat’ for
     file information; this loads the builtin ‘stat’ which will replace
     any external ‘stat’ executable.  To avoid this the following code
     can be included in an initialization file:

           zmodload -i zsh/stat
           disable stat

     The style may either be set to a ‘true’ value (or ‘all’), or one of
     the values ‘insert’ or ‘list’, indicating that files are to be
     listed in long format in all circumstances, or when attempting to
     insert a file name, or when listing file names without attempting
     to insert one.

     More generally, the value may be an array of any of the above
     values, optionally followed by ‘=’NUM.  If NUM is present it gives
     the maximum number of matches for which long listing style will be
     used.  For example,

           zstyle ':completion:*' file-list list=20 insert=10

     specifies that long format will be used when listing up to 20 files
     or inserting a file with up to 10 matches (assuming a listing is to
     be shown at all, for example on an ambiguous completion), else
     short format will be used.

           zstyle -e ':completion:*' file-list \
                  '(( ${+NUMERIC} )) && reply=(true)'

     specifies that long format will be used any time a numeric argument
     is supplied, else short format.

‘file-patterns’

     This is used by the standard function for completing filenames,
     ‘_files’.  If the style is unset up to three tags are offered,
     ‘globbed-files,directories’ and ‘all-files’, depending on the types
     of files expected by the caller of ‘_files’.  The first two
     (‘globbed-files’ and ‘directories’) are normally offered together
     to make it easier to complete files in sub-directories.

     The ‘file-patterns’ style provides alternatives to the default
     tags, which are not used.  Its value consists of elements of the
     form PATTERN‘:’TAG; each string may contain any number of such
     specifications separated by spaces.

     The PATTERN is a pattern that is to be used to generate filenames.
     Any occurrence of the sequence ‘%p’ is replaced by any pattern(s)
     passed by the function calling ‘_files’.  Colons in the pattern
     must be preceded by a backslash to make them distinguishable from
     the colon before the TAG.  If more than one pattern is needed, the
     patterns can be given inside braces, separated by commas.

     The TAGs of all strings in the value will be offered by ‘_files’
     and used when looking up other styles.  Any TAGs in the same word
     will be offered at the same time and before later words.  If no
     ‘:’TAG is given the ‘files’ tag will be used.

     The TAG may also be followed by an optional second colon and a
     description, which will be used for the ‘%d’ in the value of the
     ‘format’ style (if that is set) instead of the default description
     supplied by the completion function.  The inclusion of a
     description also gives precedence to associated options such as for
     completion grouping so it can be used where files should be
     separated.

     For example, to make the ‘rm’ command first complete only names of
     object files and then the names of all files if there is no
     matching object file:

           zstyle ':completion:*:*:rm:*:*' file-patterns \
               '*.o:object-files' '%p:all-files'

     To alter the default behaviour of file completion – offer files
     matching a pattern and directories on the first attempt, then all
     files – to offer only matching files on the first attempt, then
     directories, and finally all files:

           zstyle ':completion:*' file-patterns \
               '%p:globbed-files' '*(-/):directories' '*:all-files'

     This works even where there is no special pattern: ‘_files’ matches
     all files using the pattern ‘*’ at the first step and stops when it
     sees this pattern.  Note also it will never try a pattern more than
     once for a single completion attempt.

     To separate directories into a separate group from the files but
     still complete them at the first attempt, a description needs to be
     given.  Note that directories need to be explicitly excluded from
     the globbed-files because ‘*’ will match directories.  For
     grouping, it is also necessary to set the ‘group-name’ style.

           zstyle ':completion:*' file-patterns \
               '%p(^-/):globbed-files *(-/):directories:location'

     During the execution of completion functions, the ‘EXTENDED_GLOB’
     option is in effect, so the characters ‘#’, ‘~’ and ‘^’ have
     special meanings in the patterns.

‘file-sort’

     The standard filename completion function uses this style without a
     tag to determine in which order the names should be listed; menu
     completion will cycle through them in the same order.  The possible
     values are: ‘size’ to sort by the size of the file; ‘links’ to sort
     by the number of links to the file; ‘modification’ (or ‘time’ or
     ‘date’) to sort by the last modification time; ‘access’ to sort by
     the last access time; and ‘inode’ (or ‘change’) to sort by the last
     inode change time.  If the style is set to any other value, or is
     unset, files will be sorted alphabetically by name.  If the value
     contains the string ‘reverse’, sorting is done in the opposite
     order.  If the value contains the string ‘follow’, timestamps are
     associated with the targets of symbolic links; the default is to
     use the timestamps of the links themselves.

‘file-split-chars’

     A set of characters that will cause ‘all’ file completions for the
     given context to be split at the point where any of the characters
     occurs.  A typical use is to set the style to ‘:’; then everything
     up to and including the last ‘:’ in the string so far is ignored
     when completing files.  As this is quite heavy-handed, it is
     usually preferable to update completion functions for contexts
     where this behaviour is useful.

‘filter’

     The ‘ldap’ plugin of email address completion (see
     ‘_email_addresses’) uses this style to specify the attributes to
     match against when filtering entries.  So for example, if the style
     is set to ‘sn’, matching is done against surnames.  Standard LDAP
     filtering is used so normal completion matching is bypassed.  If
     this style is not set, the LDAP plugin is skipped.  You may also
     need to set the ‘command’ style to specify how to connect to your
     LDAP server.

‘force-list’

     This forces a list of completions to be shown at any point where
     listing is done, even in cases where the list would usually be
     suppressed.  For example, normally the list is only shown if there
     are at least two different matches.  By setting this style to
     ‘always’, the list will always be shown, even if there is only a
     single match that will immediately be accepted.  The style may also
     be set to a number.  In this case the list will be shown if there
     are at least that many matches, even if they would all insert the
     same string.

     This style is tested for the default tag as well as for each tag
     valid for the current completion.  Hence the listing can be forced
     only for certain types of match.

‘format’

     If this is set for the ‘descriptions’ tag, its value is used as a
     string to display above matches in completion lists.  The sequence
     ‘%d’ in this string will be replaced with a short description of
     what these matches are.  This string may also contain the output
     attribute sequences understood by ‘compadd -X’ (see *note
     Completion Builtin Commands: e7.).

     The style is tested with each tag valid for the current completion
     before it is tested for the ‘descriptions’ tag.  Hence different
     format strings can be defined for different types of match.

     Note also that some completer functions define additional
     ‘%’-sequences.  These are described for the completer functions
     that make use of them.

     Some completion functions display messages that may be customised
     by setting this style for the ‘messages’ tag.  Here, the ‘%d’ is
     replaced with a message given by the completion function.

     Finally, the format string is looked up with the ‘warnings’ tag,
     for use when no matches could be generated at all.  In this case
     the ‘%d’ is replaced with the descriptions for the matches that
     were expected separated by spaces.  The sequence ‘%D’ is replaced
     with the same descriptions separated by newlines.

     It is possible to use printf-style field width specifiers with ‘%d’
     and similar escape sequences.  This is handled by the ‘zformat’
     builtin command from the ‘zsh/zutil’ module, see *note The
     zsh/zutil Module: ca.

‘gain-privileges’

     If set to ‘true’, this style enables the use of commands like
     ‘sudo’ or ‘doas’ to gain extra privileges when retrieving
     information for completion.  This is only done when a command such
     as ‘sudo’ appears on the command-line.  To force the use of, e.g.
     ‘sudo’ or to override any prefix that might be added due to
     ‘gain-privileges’, the ‘command’ style can be used with a value
     that begins with a hyphen.

‘glob’

     This is used by the ‘_expand’ completer.  If it is set to ‘true’
     (the default), globbing will be attempted on the words resulting
     from a previous substitution (see the ‘substitute’ style) or else
     the original string from the line.

‘global’

     If this is set to ‘true’ (the default), the ‘_expand_alias’
     completer and bindable command will try to expand global aliases.

‘group-name’

     The completion system can group different types of matches, which
     appear in separate lists.  This style can be used to give the names
     of groups for particular tags.  For example, in command position
     the completion system generates names of builtin and external
     commands, names of aliases, shell functions and parameters and
     reserved words as possible completions.  To have the external
     commands and shell functions listed separately:

           zstyle ':completion:*:*:-command-:*:commands' \
                  group-name commands
           zstyle ':completion:*:*:-command-:*:functions' \
                  group-name functions

     As a consequence, any match with the same tag will be displayed in
     the same group.

     If the name given is the empty string the name of the tag for the
     matches will be used as the name of the group.  So, to have all
     different types of matches displayed separately, one can just set:

           zstyle ':completion:*' group-name ''

     All matches for which no group name is defined will be put in a
     group named ‘-default-’.

     To display the group name in the output, see the ‘format’ style
     (q.v.)  under the ‘descriptions’ tag.

‘group-order’

     This style is additional to the ‘group-name’ style to specify the
     order for display of the groups defined by that style (compare
     ‘tag-order’, which determines which completions appear at all).
     The groups named are shown in the given order; any other groups are
     shown in the order defined by the completion function.

     For example, to have names of builtin commands, shell functions and
     external commands appear in that order when completing in command
     position:

           zstyle ':completion:*:*:-command-:*:*' group-order \
                  builtins functions commands

‘groups’

     A list of names of UNIX groups.  If this is not set, group names
     are taken from the YP database or the file ‘/etc/group’.

‘hidden’

     If this is set to ‘true’, matches for the given context will not be
     listed, although any description for the matches set with the
     ‘format’ style will be shown.  If it is set to ‘all’, not even the
     description will be displayed.

     Note that the matches will still be completed; they are just not
     shown in the list.  To avoid having matches considered as possible
     completions at all, the ‘tag-order’ style can be modified as
     described below.

‘hosts’

     A list of names of hosts that should be completed.  If this is not
     set, hostnames are taken from the file ‘/etc/hosts’.

‘hosts-ports’

     This style is used by commands that need or accept hostnames and
     network ports.  The strings in the value should be of the form
     HOST‘:’PORT.  Valid ports are determined by the presence of
     hostnames; multiple ports for the same host may appear.

‘ignore-line’

     This is tested for each tag valid for the current completion.  If
     it is set to ‘true’, none of the words that are already on the line
     will be considered as possible completions.  If it is set to
     ‘current’, the word the cursor is on will not be considered as a
     possible completion.  The value ‘current-shown’ is similar but only
     applies if the list of completions is currently shown on the
     screen.  Finally, if the style is set to ‘other’, all words on the
     line except for the current one will be excluded from the possible
     completions.

     The values ‘current’ and ‘current-shown’ are a bit like the
     opposite of the ‘accept-exact’ style: only strings with missing
     characters will be completed.

     Note that you almost certainly don’t want to set this to ‘true’ or
     ‘other’ for a general context such as ‘:completion:*’.  This is
     because it would disallow completion of, for example, options
     multiple times even if the command in question accepts the option
     more than once.

‘ignore-parents’

     The style is tested without a tag by the function completing
     pathnames in order to determine whether to ignore the names of
     directories already mentioned in the current word, or the name of
     the current working directory.  The value must include one or both
     of the following strings:

     ‘parent’

          The name of any directory whose path is already contained in
          the word on the line is ignored.  For example, when completing
          after ‘foo/../’, the directory ‘foo’ will not be considered a
          valid completion.

     ‘pwd’

          The name of the current working directory will not be
          completed; hence, for example, completion after ‘../’ will not
          use the name of the current directory.

     In addition, the value may include one or both of:

     ‘..’

          Ignore the specified directories only when the word on the
          line contains the substring ‘../’.

     ‘directory’

          Ignore the specified directories only when names of
          directories are completed, not when completing names of files.

     Excluded values act in a similar fashion to values of the
     ‘ignored-patterns’ style, so they can be restored to consideration
     by the ‘_ignored’ completer.

‘ignored-patterns’

     A list of patterns; any trial completion matching one of the
     patterns will be excluded from consideration.  The ‘_ignored’
     completer can appear in the list of completers to restore the
     ignored matches.  This is a more configurable version of the shell
     parameter ‘$fignore’.

     Note that the ‘EXTENDED_GLOB’ option is set during the execution of
     completion functions, so the characters ‘#’, ‘~’ and ‘^’ have
     special meanings in the patterns.

‘insert’

     This style is used by the ‘_all_matches’ completer to decide
     whether to insert the list of all matches unconditionally instead
     of adding the list as another match.

‘insert-ids’

     When completing process IDs, for example as arguments to the ‘kill’
     and ‘wait’ builtins the name of a command may be converted to the
     appropriate process ID. A problem arises when the process name
     typed is not unique.  By default (or if this style is set
     explicitly to ‘menu’) the name will be converted immediately to a
     set of possible IDs, and menu completion will be started to cycle
     through them.

     If the value of the style is ‘single’, the shell will wait until
     the user has typed enough to make the command unique before
     converting the name to an ID; attempts at completion will be
     unsuccessful until that point.  If the value is any other string,
     menu completion will be started when the string typed by the user
     is longer than the common prefix to the corresponding IDs.

‘insert-sections’

     This style is used with tags of the form ‘manuals.’X when
     completing names of manual pages.  If set and the X in the tag name
     matches the section number of the page being completed, the section
     number is inserted along with the page name.  For example, given

           zstyle ':completion:*:manuals.*' insert-sections true

     ‘man ssh_<TAB>’ may be completed to ‘man 5 ssh_config’.

     The value may also be set to one of ‘prepend’, or ‘suffix’.
     ‘prepend’ behaves the same as ‘true’ as in the above example, while
     ‘suffix’ would complete ‘man ssh_<TAB>’ as ‘man ssh_config.5’.

     This is especially useful in conjunction with ‘separate-sections’,
     as it ensures that the page requested of ‘man’ corresponds to the
     one displayed in the completion listing when there are multiple
     pages with the same name (e.g., ‘printf(1)’ and ‘printf(3)’).

     The default for this style is ‘false’.

‘insert-tab’

     If this is set to ‘true’, the completion system will insert a TAB
     character (assuming that was used to start completion) instead of
     performing completion when there is no non-blank character to the
     left of the cursor.  If it is set to ‘false’, completion will be
     done even there.

     The value may also contain the substrings ‘pending’ or
     ‘pending=’VAL.  In this case, the typed character will be inserted
     instead of starting completion when there is unprocessed input
     pending.  If a VAL is given, completion will not be done if there
     are at least that many characters of unprocessed input.  This is
     often useful when pasting characters into a terminal.  Note
     however, that it relies on the ‘$PENDING’ special parameter from
     the ‘zsh/zle’ module being set properly which is not guaranteed on
     all platforms.

     The default value of this style is ‘true’ except for completion
     within ‘vared’ builtin command where it is ‘false’.

‘insert-unambiguous’

     This is used by the ‘_match’ and ‘_approximate’ completers.  These
     completers are often used with menu completion since the word typed
     may bear little resemblance to the final completion.  However, if
     this style is ‘true’, the completer will start menu completion only
     if it could find no unambiguous initial string at least as long as
     the original string typed by the user.

     In the case of the ‘_approximate’ completer, the completer field in
     the context will already have been set to one of ‘correct-’NUM or
     ‘approximate-’NUM, where NUM is the number of errors that were
     accepted.

     In the case of the ‘_match’ completer, the style may also be set to
     the string ‘pattern’.  Then the pattern on the line is left
     unchanged if it does not match unambiguously.

‘keep-prefix’

     This style is used by the ‘_expand’ completer.  If it is ‘true’,
     the completer will try to keep a prefix containing a tilde or
     parameter expansion.  Hence, for example, the string ‘~/f*’ would
     be expanded to ‘~/foo’ instead of ‘/home/user/foo’.  If the style
     is set to ‘changed’ (the default), the prefix will only be left
     unchanged if there were other changes between the expanded words
     and the original word from the command line.  Any other value
     forces the prefix to be expanded unconditionally.

     The behaviour of ‘_expand’ when this style is ‘true’ is to cause
     ‘_expand’ to give up when a single expansion with the restored
     prefix is the same as the original; hence any remaining completers
     may be called.

‘known-hosts-files’

     This style should contain a list of files to search for host names
     and (if the ‘use-ip’ style is set) IP addresses in a format
     compatible with ssh ‘known_hosts’ files.  If it is not set, the
     files ‘/etc/ssh/ssh_known_hosts’ and ‘~/.ssh/known_hosts’ are used.

‘last-prompt’

     This is a more flexible form of the ‘ALWAYS_LAST_PROMPT’ option.
     If it is ‘true’, the completion system will try to return the
     cursor to the previous command line after displaying a completion
     list.  It is tested for all tags valid for the current completion,
     then the ‘default’ tag.  The cursor will be moved back to the
     previous line if this style is ‘true’ for all types of match.  Note
     that unlike the ‘ALWAYS_LAST_PROMPT’ option this is independent of
     the numeric argument.

‘list’

     This style is used by the ‘_history_complete_word’ bindable
     command.  If it is set to ‘true’ it has no effect.  If it is set to
     ‘false’ matches will not be listed.  This overrides the setting of
     the options controlling listing behaviour, in particular
     ‘AUTO_LIST’.  The context always starts with
     ‘:completion:history-words’.

‘list-colors’

     If the ‘zsh/complist’ module is loaded, this style can be used to
     set color specifications.  This mechanism replaces the use of the
     ‘ZLS_COLORS’ and ‘ZLS_COLOURS’ parameters described in *note The
     zsh/complist Module: f4, but the syntax is the same.

     If this style is set for the ‘default’ tag, the strings in the
     value are taken as specifications that are to be used everywhere.
     If it is set for other tags, the specifications are used only for
     matches of the type described by the tag.  For this to work best,
     the ‘group-name’ style must be set to an empty string.

     In addition to setting styles for specific tags, it is also
     possible to use group names specified explicitly by the
     ‘group-name’ tag together with the ‘(group)’ syntax allowed by the
     ‘ZLS_COLORS’ and ‘ZLS_COLOURS’ parameters and simply using the
     ‘default’ tag.

     It is possible to use any color specifications already set up for
     the GNU version of the ‘ls’ command:

           zstyle ':completion:*:default' list-colors \
                  ${(s.:.)LS_COLORS}

     The default colors are the same as for the GNU ‘ls’ command and can
     be obtained by setting the style to an empty string (i.e.  ‘''’).

‘list-dirs-first’

     This is used by file completion and corresponds to a particular
     setting of the ‘file-patterns’ style.  If set, the default
     directories to be completed are listed separately from and before
     completion for other files.

‘list-grouped’

     If this style is ‘true’ (the default), the completion system will
     try to make certain completion listings more compact by grouping
     matches.  For example, options for commands that have the same
     description (shown when the ‘verbose’ style is set to ‘true’) will
     appear as a single entry.  However, menu selection can be used to
     cycle through all the matches.

‘list-packed’

     This is tested for each tag valid in the current context as well as
     the ‘default’ tag.  If it is set to ‘true’, the corresponding
     matches appear in listings as if the ‘LIST_PACKED’ option were set.
     If it is set to ‘false’, they are listed normally.

‘list-prompt’

     If this style is set for the ‘default’ tag, completion lists that
     don’t fit on the screen can be scrolled (see *note The zsh/complist
     Module: f4.).  The value, if not the empty string, will be
     displayed after every screenful and the shell will prompt for a key
     press; if the style is set to the empty string, a default prompt
     will be used.

     The value may contain the escape sequences: ‘%l’ or ‘%L’, which
     will be replaced by the number of the last line displayed and the
     total number of lines; ‘%m’ or ‘%M’, the number of the last match
     shown and the total number of matches; and ‘%p’ and ‘%P’, ‘Top’
     when at the beginning of the list, ‘Bottom’ when at the end and the
     position shown as a percentage of the total length otherwise.  In
     each case the form with the uppercase letter will be replaced by a
     string of fixed width, padded to the right with spaces, while the
     lowercase form will be replaced by a variable width string.  As in
     other prompt strings, the escape sequence ‘`%H’‘ along with ‘%S’,
     ‘%s’, ‘%B’, ‘%b’, ‘%U’, ‘%u’ for entering and leaving the display
     modes standout, bold and underline, and ‘%F’, ‘%f’, ‘%K’, ‘%k’ for
     changing the foreground background colour, are also available, as
     is the form ‘%{...%}’ for enclosing escape sequences which display
     with zero (or, with a numeric argument, some other) width.

     After deleting this prompt the variable ‘LISTPROMPT’ should be
     unset for the removal to take effect.

‘list-rows-first’

     This style is tested in the same way as the ‘list-packed’ style and
     determines whether matches are to be listed in a rows-first fashion
     as if the ‘LIST_ROWS_FIRST’ option were set.

‘list-separator’

     The value of this style is used in completion listing to separate
     the string to complete from a description when possible (e.g.  when
     completing options).  It defaults to ‘--’ (two hyphens).

‘list-suffixes’

     This style is used by the function that completes filenames.  If it
     is ‘true’, and completion is attempted on a string containing
     multiple partially typed pathname components, all ambiguous
     components will be shown.  Otherwise, completion stops at the first
     ambiguous component.

‘local’

     This is for use with functions that complete URLs for which the
     corresponding files are available directly from the file system.
     Its value should consist of three strings: a hostname, the path to
     the default web pages for the server, and the directory name used
     by a user placing web pages within their home area.

     For example:

           zstyle ':completion:*' local toast \
               /var/http/public/toast public_html

     Completion after ‘http://toast/stuff/’ will look for files in the
     directory ‘/var/http/public/toast/stuff’, while completion after
     ‘http://toast/~yousir/’ will look for files in the directory
     ‘~yousir/public_html’.

‘mail-directory’

     If set, zsh will assume that mailbox files can be found in the
     directory specified.  It defaults to ‘~/Mail’.

‘match-original’

     This is used by the ‘_match’ completer.  If it is set to ‘only’,
     ‘_match’ will try to generate matches without inserting a ‘*’ at
     the cursor position.  If set to any other non-empty value, it will
     first try to generate matches without inserting the ‘*’ and if that
     yields no matches, it will try again with the ‘*’ inserted.  If it
     is unset or set to the empty string, matching will only be
     performed with the ‘*’ inserted.

‘matcher’

     This style is tested separately for each tag valid in the current
     context.  Its value is placed before any match specifications given
     by the ‘matcher-list’ style so can override them via the use of an
     ‘x:’ specification.  The value should be in the form described in
     *note Completion Matching Control: eb.  For examples of this, see
     the description of the ‘tag-order’ style.

     For notes comparing the use of this and the ‘matcher-list’ style,
     see under the description of the ‘tag-order’ style.

‘matcher-list’

     This style can be set to a list of match specifications that are to
     be applied everywhere.  Match specifications are described in *note
     Completion Matching Control: eb.  The completion system will try
     them one after another for each completer selected.  For example,
     to try first simple completion and, if that generates no matches,
     case-insensitive completion:

           zstyle ':completion:*' matcher-list '' 'm:{a-zA-Z}={A-Za-z}'

     By default each specification replaces the previous one; however,
     if a specification is prefixed with ‘+’, it is added to the
     existing list.  Hence it is possible to create increasingly general
     specifications without repetition:

           zstyle ':completion:*' matcher-list \
                  '' '+m:{a-z}={A-Z}' '+m:{A-Z}={a-z}'

     It is possible to create match specifications valid for particular
     completers by using the third field of the context.  This applies
     only to completers that override the global matcher-list, which as
     of this writing includes only ‘_prefix’ and ‘_ignored’.  For
     example, to use the completers ‘_complete’ and ‘_prefix’ but allow
     case-insensitive completion only with ‘_complete’:

           zstyle ':completion:*' completer _complete _prefix
           zstyle ':completion:*:complete:*:*:*' matcher-list \
                  '' 'm:{a-zA-Z}={A-Za-z}'

     User-defined names, as explained for the ‘completer’ style, are
     available.  This makes it possible to try the same completer more
     than once with different match specifications each time.  For
     example, to try normal completion without a match specification,
     then normal completion with case-insensitive matching, then
     correction, and finally partial-word completion:

           zstyle ':completion:*' completer \
               _complete _correct _complete:foo
           zstyle ':completion:*:complete:*:*:*' matcher-list \
               '' 'm:{a-zA-Z}={A-Za-z}'
           zstyle ':completion:*:foo:*:*:*' matcher-list \
               'm:{a-zA-Z}={A-Za-z} r:|[-_./]=* r:|=*'

     If the style is unset in any context no match specification is
     applied.  Note also that some completers such as ‘_correct’ and
     ‘_approximate’ do not use the match specifications at all, though
     these completers will only ever be called once even if the
     ‘matcher-list’ contains more than one element.

     Where multiple specifications are useful, note that the ‘entire’
     completion is done for each element of ‘matcher-list’, which can
     quickly reduce the shell’s performance.  As a rough rule of thumb,
     one to three strings will give acceptable performance.  On the
     other hand, putting multiple space-separated values into the same
     string does not have an appreciable impact on performance.

     If there is no current matcher or it is empty, and the option
     ‘NO_CASE_GLOB’ is in effect, the matching for files is performed
     case-insensitively in any case.  However, any matcher must
     explicitly specify case-insensitive matching if that is required.

     For notes comparing the use of this and the ‘matcher’ style, see
     under the description of the ‘tag-order’ style.

‘max-errors’

     This is used by the ‘_approximate’ and ‘_correct’ completer
     functions to determine the maximum number of errors to allow.  The
     completer will try to generate completions by first allowing one
     error, then two errors, and so on, until either a match or matches
     were found or the maximum number of errors given by this style has
     been reached.

     If the value for this style contains the string ‘numeric’, the
     completer function will take any numeric argument as the maximum
     number of errors allowed.  For example, with

           zstyle ':completion:*:approximate:::' max-errors 2 numeric

     two errors are allowed if no numeric argument is given, but with a
     numeric argument of six (as in ‘ESC-6 TAB’), up to six errors are
     accepted.  Hence with a value of ‘0 numeric’, no correcting
     completion will be attempted unless a numeric argument is given.

     If the value contains the string ‘not-numeric’, the completer will
     ‘not’ try to generate corrected completions when given a numeric
     argument, so in this case the number given should be greater than
     zero.  For example, ‘2 not-numeric’ specifies that correcting
     completion with two errors will usually be performed, but if a
     numeric argument is given, correcting completion will not be
     performed.

     The default value for this style is ‘2 numeric’.

‘max-matches-width’

     This style is used to determine the trade off between the width of
     the display used for matches and the width used for their
     descriptions when the ‘verbose’ style is in effect.  The value
     gives the number of display columns to reserve for the matches.
     The default is half the width of the screen.

     This has the most impact when several matches have the same
     description and so will be grouped together.  Increasing the style
     will allow more matches to be grouped together; decreasing it will
     allow more of the description to be visible.

‘menu’

     If this is ‘true’ in the context of any of the tags defined for the
     current completion menu completion will be used.  The value for a
     specific tag will take precedence over that for the ‘default’ tag.

     If none of the values found in this way is ‘true’ but at least one
     is set to ‘auto’, the shell behaves as if the ‘AUTO_MENU’ option is
     set.

     If one of the values is explicitly set to ‘false’, menu completion
     will be explicitly turned off, overriding the ‘MENU_COMPLETE’
     option and other settings.

     In the form ‘yes=’NUM, where ‘yes’ may be any of the ‘true’ values
     (‘yes’, ‘true’, ‘on’ and ‘1’), menu completion will be turned on if
     there are at least NUM matches.  In the form ‘yes=long’, menu
     completion will be turned on if the list does not fit on the
     screen.  This does not activate menu completion if the widget
     normally only lists completions, but menu completion can be
     activated in that case with the value ‘yes=long-list’ (Typically,
     the value ‘select=long-list’ described later is more useful as it
     provides control over scrolling.)

     Similarly, with any of the ‘false’ values (as in ‘no=10’), menu
     completion will ‘not’ be used if there are NUM or more matches.

     The value of this widget also controls menu selection, as
     implemented by the ‘zsh/complist’ module.  The following values may
     appear either alongside or instead of the values above.

     If the value contains the string ‘select’, menu selection will be
     started unconditionally.

     In the form ‘select=’NUM, menu selection will only be started if
     there are at least NUM matches.  If the values for more than one
     tag provide a number, the smallest number is taken.

     Menu selection can be turned off explicitly by defining a value
     containing the stringtt(no-select).

     It is also possible to start menu selection only if the list of
     matches does not fit on the screen by using the value
     ‘select=long’.  To start menu selection even if the current widget
     only performs listing, use the value ‘select=long-list’.

     To turn on menu completion or menu selection when there are a
     certain number of matches ‘or’ the list of matches does not fit on
     the screen, both of ‘yes=’ and ‘select=’ may be given twice, once
     with a number and once with ‘long’ or ‘long-list’.

     Finally, it is possible to activate two special modes of menu
     selection.  The word ‘interactive’ in the value causes interactive
     mode to be entered immediately when menu selection is started; see
     *note The zsh/complist Module: f4. for a description of interactive
     mode.  Including the string ‘search’ does the same for incremental
     search mode.  To select backward incremental search, include the
     string ‘search-backward’.

‘muttrc’

     If set, gives the location of the mutt configuration file.  It
     defaults to ‘~/.muttrc’.

‘numbers’

     This is used with the ‘jobs’ tag.  If it is ‘true’, the shell will
     complete job numbers instead of the shortest unambiguous prefix of
     the job command text.  If the value is a number, job numbers will
     only be used if that many words from the job descriptions are
     required to resolve ambiguities.  For example, if the value is ‘1’,
     strings will only be used if all jobs differ in the first word on
     their command lines.

‘old-list’

     This is used by the ‘_oldlist’ completer.  If it is set to
     ‘always’, then standard widgets which perform listing will retain
     the current list of matches, however they were generated; this can
     be turned off explicitly with the value ‘never’, giving the
     behaviour without the ‘_oldlist’ completer.  If the style is unset,
     or any other value, then the existing list of completions is
     displayed if it is not already; otherwise, the standard completion
     list is generated; this is the default behaviour of ‘_oldlist’.
     However, if there is an old list and this style contains the name
     of the completer function that generated the list, then the old
     list will be used even if it was generated by a widget which does
     not do listing.

     For example, suppose you type ‘^Xc’ to use the ‘_correct_word’
     widget, which generates a list of corrections for the word under
     the cursor.  Usually, typing ‘^D’ would generate a standard list of
     completions for the word on the command line, and show that.  With
     ‘_oldlist’, it will instead show the list of corrections already
     generated.

     As another example consider the ‘_match’ completer: with the
     ‘insert-unambiguous’ style set to ‘true’ it inserts only a common
     prefix string, if there is any.  However, this may remove parts of
     the original pattern, so that further completion could produce more
     matches than on the first attempt.  By using the ‘_oldlist’
     completer and setting this style to ‘_match’, the list of matches
     generated on the first attempt will be used again.

‘old-matches’

     This is used by the ‘_all_matches’ completer to decide if an old
     list of matches should be used if one exists.  This is selected by
     one of the ‘true’ values or by the string ‘only’.  If the value is
     ‘only’, ‘_all_matches’ will only use an old list and won’t have any
     effect on the list of matches currently being generated.

     If this style is set it is generally unwise to call the
     ‘_all_matches’ completer unconditionally.  One possible use is for
     either this style or the ‘completer’ style to be defined with the
     ‘-e’ option to ‘zstyle’ to make the style conditional.

‘old-menu’

     This is used by the ‘_oldlist’ completer.  It controls how menu
     completion behaves when a completion has already been inserted and
     the user types a standard completion key such as ‘TAB’.  The
     default behaviour of ‘_oldlist’ is that menu completion always
     continues with the existing list of completions.  If this style is
     set to ‘false’, however, a new completion is started if the old
     list was generated by a different completion command; this is the
     behaviour without the ‘_oldlist’ completer.

     For example, suppose you type ‘^Xc’ to generate a list of
     corrections, and menu completion is started in one of the usual
     ways.  Usually, or with this style set to ‘false’, typing ‘TAB’ at
     this point would start trying to complete the line as it now
     appears.  With ‘_oldlist’, it instead continues to cycle through
     the list of corrections.

‘original’

     This is used by the ‘_approximate’ and ‘_correct’ completers to
     decide if the original string should be added as a possible
     completion.  Normally, this is done only if there are at least two
     possible corrections, but if this style is set to ‘true’, it is
     always added.  Note that the style will be examined with the
     completer field in the context name set to ‘correct-’NUM or
     ‘approximate-’NUM, where NUM is the number of errors that were
     accepted.

‘packageset’

     This style is used when completing arguments of the Debian ‘dpkg’
     program.  It contains an override for the default package set for a
     given context.  For example,

           zstyle ':completion:*:complete:dpkg:option--status-1:*' \
                          packageset avail

     causes available packages, rather than only installed packages, to
     be completed for ‘dpkg --status’.

‘path’

     The function that completes color names uses this style with the
     ‘colors’ tag.  The value should be the pathname of a file
     containing color names in the format of an X11 ‘rgb.txt’ file.  If
     the style is not set but this file is found in one of various
     standard locations it will be used as the default.

‘path-completion’

     This is used by filename completion.  By default, filename
     completion examines all components of a path to see if there are
     completions of that component.  For example, ‘/u/b/z’ can be
     completed to ‘/usr/bin/zsh’.  Explicitly setting this style to
     ‘false’ inhibits this behaviour for path components up to the ‘/’
     before the cursor; this overrides the setting of
     ‘accept-exact-dirs’.

     Even with the style set to ‘false’, it is still possible to
     complete multiple paths by setting the option ‘COMPLETE_IN_WORD’
     and moving the cursor back to the first component in the path to be
     completed.  For example, ‘/u/b/z’ can be completed to
     ‘/usr/bin/zsh’ if the cursor is after the ‘/u’.

‘pine-directory’

     If set, specifies the directory containing PINE mailbox files.
     There is no default, since recursively searching this directory is
     inconvenient for anyone who doesn’t use PINE.

‘ports’

     A list of Internet service names (network ports) to complete.  If
     this is not set, service names are taken from the file
     ‘/etc/services’.

‘prefix-hidden’

     This is used for certain completions which share a common prefix,
     for example command options beginning with dashes.  If it is
     ‘true’, the prefix will not be shown in the list of matches.

     The default value for this style is ‘false’.

‘prefix-needed’

     This style is also relevant for matches with a common prefix.  If
     it is set to ‘true’ this common prefix must be typed by the user to
     generate the matches.

     The style is applicable to the ‘options’, ‘signals’, ‘jobs’,
     ‘functions’, and ‘parameters’ completion tags.

     For command options, this means that the initial ‘-’, ‘+’, or ‘--’
     must be typed explicitly before option names will be completed.

     For signals, an initial ‘-’ is required before signal names will be
     completed.

     For jobs, an initial ‘%’ is required before job names will be
     completed.

     For function and parameter names, an initial ‘_’ or ‘.’ is required
     before function or parameter names starting with those characters
     will be completed.

     The default value for this style is ‘false’ for ‘function’ and
     ‘parameter’ completions, and ‘true’ otherwise.

‘preserve-prefix’

     This style is used when completing path names.  Its value should be
     a pattern matching an initial prefix of the word to complete that
     should be left unchanged under all circumstances.  For example, on
     some Unices an initial ‘//’ (double slash) has a special meaning;
     setting this style to the string ‘//’ will preserve it.  As another
     example, setting this style to ‘?:/’ under Cygwin would allow
     completion after ‘a:/...’ and so on.

‘range’

     This is used by the ‘_history’ completer and the
     ‘_history_complete_word’ bindable command to decide which words
     should be completed.

     If it is a single number, only the last N words from the history
     will be completed.

     If it is a range of the form MAX‘:’SLICE, the last SLICE words will
     be completed; then if that yields no matches, the SLICE words
     before those will be tried and so on.  This process stops either
     when at least one match has been found, or MAX words have been
     tried.

     The default is to complete all words from the history at once.

‘recursive-files’

     If this style is set, its value is an array of patterns to be
     tested against ‘$PWD/’: note the trailing slash, which allows
     directories in the pattern to be delimited unambiguously by
     including slashes on both sides.  If an ordinary file completion
     fails and the word on the command line does not yet have a
     directory part to its name, the style is retrieved using the same
     tag as for the completion just attempted, then the elements tested
     against ‘$PWD/’ in turn.  If one matches, then the shell reattempts
     completion by prepending the word on the command line with each
     directory in the expansion of ‘**/*(/)’ in turn.  Typically the
     elements of the style will be set to restrict the number of
     directories beneath the current one to a manageable number, for
     example ‘*/.git/*’.

     For example,

           zstyle ':completion:*' recursive-files '*/zsh/*'

     If the current directory is ‘/home/pws/zsh/Src’, then ‘zle_tr<TAB>’
     can be completed to ‘Zle/zle_tricky.c’.

‘regular’

     This style is used by the ‘_expand_alias’ completer and bindable
     command.  If set to ‘true’ (the default), regular aliases will be
     expanded but only in command position.  If it is set to ‘false’,
     regular aliases will never be expanded.  If it is set to ‘always’,
     regular aliases will be expanded even if not in command position.

‘rehash’

     If this is set when completing external commands, the internal list
     (hash) of commands will be updated for each search by issuing the
     ‘rehash’ command.  There is a speed penalty for this which is only
     likely to be noticeable when directories in the path have slow file
     access.

‘remote-access’

     If set to ‘false’, certain commands will be prevented from making
     Internet connections to retrieve remote information.  This includes
     the completion for the ‘CVS’ command.

     It is not always possible to know if connections are in fact to a
     remote site, so some may be prevented unnecessarily.

‘remove-all-dups’

     The ‘_history_complete_word’ bindable command and the ‘_history’
     completer use this to decide if all duplicate matches should be
     removed, rather than just consecutive duplicates.

‘select-prompt’

     If this is set for the ‘default’ tag, its value will be displayed
     during menu selection (see the ‘menu’ style above) when the
     completion list does not fit on the screen as a whole.  The same
     escapes as for the ‘list-prompt’ style are understood, except that
     the numbers refer to the match or line the mark is on.  A default
     prompt is used when the value is the empty string.

‘select-scroll’

     This style is tested for the ‘default’ tag and determines how a
     completion list is scrolled during a menu selection (see the ‘menu’
     style above) when the completion list does not fit on the screen as
     a whole.  If the value is ‘0’ (zero), the list is scrolled by
     half-screenfuls; if it is a positive integer, the list is scrolled
     by the given number of lines; if it is a negative number, the list
     is scrolled by a screenful minus the absolute value of the given
     number of lines.  The default is to scroll by single lines.

‘separate-sections’

     This style is used with the ‘manuals’ tag when completing names of
     manual pages.  If it is ‘true’, entries for different sections are
     added separately using tag names of the form ‘manuals.’X, where X
     is the section number.  When the ‘group-name’ style is also in
     effect, pages from different sections will appear separately.  This
     style is also used similarly with the ‘words’ style when completing
     words for the dict command.  It allows words from different
     dictionary databases to be added separately.  See also
     ‘insert-sections’.

     The default for this style is ‘false’.

‘show-ambiguity’

     If the ‘zsh/complist’ module is loaded, this style can be used to
     highlight the first ambiguous character in completion lists.  The
     value is either a color indication such as those supported by the
     ‘list-colors’ style or, with a value of ‘true’, a default of
     underlining is selected.  The highlighting is only applied if the
     completion display strings correspond to the actual matches.

‘show-completer’

     Tested whenever a new completer is tried.  If it is ‘true’, the
     completion system outputs a progress message in the listing area
     showing what completer is being tried.  The message will be
     overwritten by any output when completions are found and is removed
     after completion is finished.

‘single-ignored’

     This is used by the ‘_ignored’ completer when there is only one
     match.  If its value is ‘show’, the single match will be displayed
     but not inserted.  If the value is ‘menu’, then the single match
     and the original string are both added as matches and menu
     completion is started, making it easy to select either of them.

‘sort’

     This allows the standard ordering of matches to be overridden.

     If its value is ‘true’ or ‘false’, sorting is enabled or disabled.
     Additionally the values associated with the ‘-o’ option to
     ‘compadd’ can also be listed: ‘match’, ‘nosort’, ‘numeric’,
     ‘reverse’.  If it is not set for the context, the standard
     behaviour of the calling widget is used.

     The style is tested first against the full context including the
     tag, and if that fails to produce a value against the context
     without the tag.

     In many cases where a calling widget explicitly selects a
     particular ordering in lieu of the default, a value of ‘true’ is
     not honoured.  An example of where this is not the case is for
     command history where the default of sorting matches
     chronologically may be overridden by setting the style to ‘true’.

     In the ‘_expand’ completer, if it is set to ‘true’, the expansions
     generated will always be sorted.  If it is set to ‘menu’, then the
     expansions are only sorted when they are offered as single strings
     but not in the string containing all possible expansions.

‘special-dirs’

     Normally, the completion code will not produce the directory names
     ‘.’ and ‘..’ as possible completions.  If this style is set to
     ‘true’, it will add both ‘.’ and ‘..’ as possible completions; if
     it is set to ‘..’, only ‘..’ will be added.

     The following example sets ‘special-dirs’ to ‘..’ when the current
     prefix is empty, is a single ‘.’, or consists only of a path
     beginning with ‘../’.  Otherwise the value is ‘false’.

           zstyle -e ':completion:*' special-dirs \
              '[[ $PREFIX = (../)#(|.|..) ]] && reply=(..)'

‘squeeze-slashes’

     If set to ‘true’, sequences of slashes in filename paths (for
     example in ‘foo//bar’) will be treated as a single slash.  This is
     the usual behaviour of UNIX paths.  However, by default the file
     completion function behaves as if there were a ‘*’ between the
     slashes.

‘stop’

     If set to ‘true’, the ‘_history_complete_word’ bindable command
     will stop once when reaching the beginning or end of the history.
     Invoking ‘_history_complete_word’ will then wrap around to the
     opposite end of the history.  If this style is set to ‘false’ (the
     default), ‘_history_complete_word’ will loop immediately as in a
     menu completion.

‘strip-comments’

     If set to ‘true’, this style causes non-essential comment text to
     be removed from completion matches.  Currently it is only used when
     completing e-mail addresses where it removes any display name from
     the addresses, cutting them down to plain USER@HOST form.

‘subst-globs-only’

     This is used by the ‘_expand’ completer.  If it is set to ‘true’,
     the expansion will only be used if it resulted from globbing;
     hence, if expansions resulted from the use of the ‘substitute’
     style described below, but these were not further changed by
     globbing, the expansions will be rejected.

     The default for this style is ‘false’.

‘substitute’

     This boolean style controls whether the ‘_expand’ completer will
     first try to expand all substitutions in the string (such as
     ‘$(’…‘)’ and ‘${’…‘}’).

     The default is ‘true’.

‘suffix’

     This is used by the ‘_expand’ completer if the word starts with a
     tilde or contains a parameter expansion.  If it is set to ‘true’,
     the word will only be expanded if it doesn’t have a suffix, i.e.
     if it is something like ‘~foo’ or ‘$foo’ rather than ‘~foo/’ or
     ‘$foo/bar’, unless that suffix itself contains characters eligible
     for expansion.  The default for this style is ‘true’.

‘tag-order’

     This provides a mechanism for sorting how the tags available in a
     particular context will be used.

     The values for the style are sets of space-separated lists of tags.
     The tags in each value will be tried at the same time; if no match
     is found, the next value is used.  (See the ‘file-patterns’ style
     for an exception to this behavior.)

     For example:

           zstyle ':completion:*:complete:-command-:*:*' tag-order \
               'commands functions'

     specifies that completion in command position first offers external
     commands and shell functions.  Remaining tags will be tried if no
     completions are found.

     In addition to tag names, each string in the value may take one of
     the following forms:

     ‘-’

          If any value consists of only a hyphen, then ‘only’ the tags
          specified in the other values are generated.  Normally all
          tags not explicitly selected are tried last if the specified
          tags fail to generate any matches.  This means that a single
          value consisting only of a single hyphen turns off completion.

     ‘!’  TAGS…

          A string starting with an exclamation mark specifies names of
          tags that are ‘not’ to be used.  The effect is the same as if
          all other possible tags for the context had been listed.

     TAG‘:’LABEL …

          Here, TAG is one of the standard tags and LABEL is an
          arbitrary name.  Matches are generated as normal but the name
          LABEL is used in contexts instead of TAG.  This is not useful
          in words starting with ‘!’.

          If the LABEL starts with a hyphen, the TAG is prepended to the
          LABEL to form the name used for lookup.  This can be used to
          make the completion system try a certain tag more than once,
          supplying different style settings for each attempt; see below
          for an example.

     TAG‘:’LABEL‘:’DESCRIPTION

          As before, but ‘description’ will replace the ‘%d’ in the
          value of the ‘format’ style instead of the default description
          supplied by the completion function.  Spaces in the
          description must be quoted with a backslash.  A ‘%d’ appearing
          in DESCRIPTION is replaced with the description given by the
          completion function.

     In any of the forms above the tag may be a pattern or several
     patterns in the form ‘{’PAT1‘,’PAT2…‘}’.  In this case all matching
     tags will be used except for any given explicitly in the same
     string.

     One use of these features is to try one tag more than once, setting
     other styles differently on each attempt, but still to use all the
     other tags without having to repeat them all.  For example, to make
     completion of function names in command position ignore all the
     completion functions starting with an underscore the first time
     completion is tried:

           zstyle ':completion:*:*:-command-:*:*' tag-order \
               'functions:-non-comp *' functions
           zstyle ':completion:*:functions-non-comp' \
               ignored-patterns '_*'

     On the first attempt, all tags will be offered but the ‘functions’
     tag will be replaced by ‘functions-non-comp’.  The
     ‘ignored-patterns’ style is set for this tag to exclude functions
     starting with an underscore.  If there are no matches, the second
     value of the ‘tag-order’ style is used which completes functions
     using the default tag, this time presumably including all function
     names.

     The matches for one tag can be split into different groups.  For
     example:

           zstyle ':completion:*' tag-order \
               'options:-long:long\ options
                options:-short:short\ options
                options:-single-letter:single\ letter\ options'
           zstyle ':completion:*:options-long' \
                ignored-patterns '[-+](|-|[^-]*)'
           zstyle ':completion:*:options-short' \
                ignored-patterns '--*' '[-+]?'
           zstyle ':completion:*:options-single-letter' \
                ignored-patterns '???*'

     With the ‘group-names’ style set, options beginning with ‘--’,
     options beginning with a single ‘-’ or ‘+’ but containing multiple
     characters, and single-letter options will be displayed in separate
     groups with different descriptions.

     Another use of patterns is to try multiple match specifications one
     after another.  The ‘matcher-list’ style offers something similar,
     but it is tested very early in the completion system and hence
     can’t be set for single commands nor for more specific contexts.
     Here is how to try normal completion without any match
     specification and, if that generates no matches, try again with
     case-insensitive matching, restricting the effect to arguments of
     the command ‘foo’:

           zstyle ':completion:*:*:foo:*:*' tag-order '*' '*:-case'
           zstyle ':completion:*-case' matcher 'm:{a-z}={A-Z}'

     First, all the tags offered when completing after ‘foo’ are tried
     using the normal tag name.  If that generates no matches, the
     second value of ‘tag-order’ is used, which tries all tags again
     except that this time each has ‘-case’ appended to its name for
     lookup of styles.  Hence this time the value for the ‘matcher’
     style from the second call to ‘zstyle’ in the example is used to
     make completion case-insensitive.

     It is possible to use the ‘-e’ option of the ‘zstyle’ builtin
     command to specify conditions for the use of particular tags.  For
     example:

           zstyle -e '*:-command-:*' tag-order '
               if [[ -n $PREFIX$SUFFIX ]]; then
                 reply=( )
               else
                 reply=( - )
               fi'

     Completion in command position will be attempted only if the string
     typed so far is not empty.  This is tested using the ‘PREFIX’
     special parameter; see *note Completion Special Parameters: e6. for
     a description of parameters which are special inside completion
     widgets.  Setting ‘reply’ to an empty array provides the default
     behaviour of trying all tags at once; setting it to an array
     containing only a hyphen disables the use of all tags and hence of
     all completions.

     If no ‘tag-order’ style has been defined for a context, the strings
     ‘(|*-)argument-* (|*-)option-* values’ and ‘options’ plus all tags
     offered by the completion function will be used to provide a
     sensible default behavior that causes arguments (whether normal
     command arguments or arguments of options) to be completed before
     option names for most commands.

‘urls’

     This is used together with the ‘urls’ tag by functions completing
     URLs.

     If the value consists of more than one string, or if the only
     string does not name a file or directory, the strings are used as
     the URLs to complete.

     If the value contains only one string which is the name of a normal
     file the URLs are taken from that file (where the URLs may be
     separated by white space or newlines).

     Finally, if the only string in the value names a directory, the
     directory hierarchy rooted at this directory gives the completions.
     The top level directory should be the file access method, such as
     ‘http’, ‘ftp’, ‘bookmark’ and so on.  In many cases the next level
     of directories will be a filename.  The directory hierarchy can
     descend as deep as necessary.

     For example,

           zstyle ':completion:*' urls ~/.urls
           mkdir -p ~/.urls/ftp/ftp.zsh.org/pub

     allows completion of all the components of the URL
     ‘ftp://ftp.zsh.org/pub’ after suitable commands such as ‘netscape’
     or ‘lynx’.  Note, however, that access methods and files are
     completed separately, so if the ‘hosts’ style is set hosts can be
     completed without reference to the ‘urls’ style.

     See the description in the function ‘_urls’ itself for more
     information (e.g.  ‘more $^fpath/_urls(N)’).

‘use-cache’

     If this is set, the completion caching layer is activated for any
     completions which use it (via the ‘_store_cache’,
     ‘_retrieve_cache’, and ‘_cache_invalid’ functions).  The directory
     containing the cache files can be changed with the ‘cache-path’
     style.

‘use-compctl’

     If this style is set to a string ‘not’ equal to ‘false’, ‘0’, ‘no’,
     and ‘off’, the completion system may use any completion
     specifications defined with the ‘compctl’ builtin command.  If the
     style is unset, this is done only if the ‘zsh/compctl’ module is
     loaded.  The string may also contain the substring ‘first’ to use
     completions defined with ‘compctl -T’, and the substring ‘default’
     to use the completion defined with ‘compctl -D’.

     Note that this is only intended to smooth the transition from
     ‘compctl’ to the new completion system and may disappear in the
     future.

     Note also that the definitions from ‘compctl’ will only be used if
     there is no specific completion function for the command in
     question.  For example, if there is a function ‘_foo’ to complete
     arguments to the command ‘foo’, ‘compctl’ will never be invoked for
     ‘foo’.  However, the ‘compctl’ version will be tried if ‘foo’ only
     uses default completion.

‘use-ip’

     By default, the function ‘_hosts’ that completes host names strips
     IP addresses from entries read from host databases such as NIS and
     ssh files.  If this style is ‘true’, the corresponding IP addresses
     can be completed as well.  This style is not use in any context
     where the ‘hosts’ style is set; note also it must be set before the
     cache of host names is generated (typically the first completion
     attempt).

‘users’

     This may be set to a list of usernames to be completed.  If it is
     not set all usernames will be completed.  Note that if it is set
     only that list of users will be completed; this is because on some
     systems querying all users can take a prohibitive amount of time.

‘users-hosts’

     The values of this style should be of the form USER‘@’HOST or
     USER‘:’HOST.  It is used for commands that need pairs of user- and
     hostnames.  These commands will complete usernames from this style
     (only), and will restrict subsequent hostname completion to hosts
     paired with that user in one of the values of the style.

     It is possible to group values for sets of commands which allow a
     remote login, such as ‘rlogin’ and ‘ssh’, by using the
     ‘my-accounts’ tag.  Similarly, values for sets of commands which
     usually refer to the accounts of other people, such as ‘talk’ and
     ‘finger’, can be grouped by using the ‘other-accounts’ tag.  More
     ambivalent commands may use the ‘accounts’ tag.

‘users-hosts-ports’

     Like ‘users-hosts’ but used for commands like ‘telnet’ and
     containing strings of the form USER‘@’HOST‘:’PORT.

‘verbose’

     If set, as it is by default, the completion listing is more
     verbose.  In particular many commands show descriptions for options
     if this style is ‘true’.

‘word’

     This is used by the ‘_list’ completer, which prevents the insertion
     of completions until a second completion attempt when the line has
     not changed.  The normal way of finding out if the line has changed
     is to compare its entire contents between the two occasions.  If
     this style is ‘true’, the comparison is instead performed only on
     the current word.  Hence if completion is performed on another word
     with the same contents, completion will not be delayed.


File: zsh.info,  Node: Control Functions,  Next: Bindable Commands,  Prev: Completion System Configuration,  Up: Completion System

19.4 Control Functions
======================

The initialization script ‘compinit’ redefines all the widgets which
perform completion to call the supplied widget function
‘_main_complete’.  This function acts as a wrapper calling the so-called
‘completer’ functions that generate matches.  If ‘_main_complete’ is
called with arguments, these are taken as the names of completer
functions to be called in the order given.  If no arguments are given,
the set of functions to try is taken from the ‘completer’ style.  For
example, to use normal completion and correction if that doesn’t
generate any matches:

      zstyle ':completion:*' completer _complete _correct

after calling ‘compinit’.  The default value for this style is
‘_complete _ignored’, i.e.  normally only ordinary completion is tried,
first with the effect of the ‘ignored-patterns’ style and then without
it.  The ‘_main_complete’ function uses the return status of the
completer functions to decide if other completers should be called.  If
the return status is zero, no other completers are tried and the
‘_main_complete’ function returns.

If the first argument to ‘_main_complete’ is a single hyphen, the
arguments will not be taken as names of completers.  Instead, the second
argument gives a name to use in the COMPLETER field of the context and
the other arguments give a command name and arguments to call to
generate the matches.

The following completer functions are contained in the distribution,
although users may write their own.  Note that in contexts the leading
underscore is stripped, for example basic completion is performed in the
context ‘:completion::complete:’….

‘_all_matches’

     This completer can be used to add a string consisting of all other
     matches.  As it influences later completers it must appear as the
     first completer in the list.  The list of all matches is affected
     by the ‘avoid-completer’ and ‘old-matches’ styles described above.

     It may be useful to use the ‘_generic’ function described below to
     bind ‘_all_matches’ to its own keystroke, for example:

           zle -C all-matches complete-word _generic
           bindkey '^Xa' all-matches
           zstyle ':completion:all-matches:*' old-matches only
           zstyle ':completion:all-matches::::' completer _all_matches

     Note that this does not generate completions by itself: first use
     any of the standard ways of generating a list of completions, then
     use ‘^Xa’ to show all matches.  It is possible instead to add a
     standard completer to the list and request that the list of all
     matches should be directly inserted:

           zstyle ':completion:all-matches::::' completer \
                  _all_matches _complete
           zstyle ':completion:all-matches:*' insert true

     In this case the ‘old-matches’ style should not be set.

‘_approximate’

     This is similar to the basic ‘_complete’ completer but allows the
     completions to undergo corrections.  The maximum number of errors
     can be specified by the ‘max-errors’ style; see *note Approximate
     Matching: 82. for how errors are counted.  Normally this completer
     will only be tried after the normal ‘_complete’ completer:

           zstyle ':completion:*' completer _complete _approximate

     This will give correcting completion if and only if normal
     completion yields no possible completions.  When corrected
     completions are found, the completer will normally start menu
     completion allowing you to cycle through these strings.

     This completer uses the tags ‘corrections’ and ‘original’ when
     generating the possible corrections and the original string.  The
     ‘format’ style for the former may contain the additional sequences
     ‘%e’ and ‘%o’ which will be replaced by the number of errors
     accepted to generate the corrections and the original string,
     respectively.

     The completer progressively increases the number of errors allowed
     up to the limit by the ‘max-errors’ style, hence if a completion is
     found with one error, no completions with two errors will be shown,
     and so on.  It modifies the completer name in the context to
     indicate the number of errors being tried: on the first try the
     completer field contains ‘approximate-1’, on the second try
     ‘approximate-2’, and so on.

     When ‘_approximate’ is called from another function, the number of
     errors to accept may be passed with the ‘-a’ option.  The argument
     is in the same format as the ‘max-errors’ style, all in one string.

     Note that this completer (and the ‘_correct’ completer mentioned
     below) can be quite expensive to call, especially when a large
     number of errors are allowed.  One way to avoid this is to set up
     the ‘completer’ style using the ‘-e’ option to zstyle so that some
     completers are only used when completion is attempted a second time
     on the same string, e.g.:

           zstyle -e ':completion:*' completer '
             if [[ $_last_try != "$HISTNO$BUFFER$CURSOR" ]]; then
               _last_try="$HISTNO$BUFFER$CURSOR"
               reply=(_complete _match _prefix)
             else
               reply=(_ignored _correct _approximate)
             fi'

     This uses the ‘HISTNO’ parameter and the ‘BUFFER’ and ‘CURSOR’
     special parameters that are available inside zle and completion
     widgets to find out if the command line hasn’t changed since the
     last time completion was tried.  Only then are the ‘_ignored’,
     ‘_correct’ and ‘_approximate’ completers called.

‘_canonical_paths’ [ ‘-A’ VAR ] [ ‘-N’ ] [ ‘-MJV12nfX’ ] TAG DESCR [
PATHS … ]

     This completion function completes all paths given to it, and also
     tries to offer completions which point to the same file as one of
     the paths given (relative path when an absolute path is given, and
     vice versa; when ‘..’’s are present in the word to be completed;
     and some paths got from symlinks).

     ‘-A’, if specified, takes the paths from the array variable
     specified.  Paths can also be specified on the command line as
     shown above.  ‘-N’, if specified, prevents canonicalizing the paths
     given before using them for completion, in case they are already
     so.  The options ‘-M’, ‘-J’, ‘-V’, ‘-1’, ‘-2’, ‘-n’, ‘-F’, ‘-X’ are
     passed to ‘compadd’.

     See ‘_description’ for a description of TAG and DESCR.

‘_cmdambivalent’

     Completes the remaining positional arguments as an external
     command.  The external command and its arguments are completed as
     separate arguments (in a manner appropriate for completing
     ‘/usr/bin/env’) if there are two or more remaining positional
     arguments on the command line, and as a quoted command string (in
     the manner of ‘system(...)’) otherwise.  See also ‘_cmdstring’ and
     ‘_precommand’.

     This function takes no arguments.

‘_cmdstring’

     Completes an external command as a single argument, as for
     ‘system(...)’.

‘_complete’

     This completer generates all possible completions in a
     context-sensitive manner, i.e.  using the settings defined with the
     ‘compdef’ function explained above and the current settings of all
     special parameters.  This gives the normal completion behaviour.

     To complete arguments of commands, ‘_complete’ uses the utility
     function ‘_normal’, which is in turn responsible for finding the
     particular function; it is described below.  Various contexts of
     the form ‘-’CONTEXT‘-’ are handled specifically.  These are all
     mentioned above as possible arguments to the ‘#compdef’ tag.

     Before trying to find a function for a specific context,
     ‘_complete’ checks if the parameter ‘compcontext’ is set.  Setting
     ‘compcontext’ allows the usual completion dispatching to be
     overridden which is useful in places such as a function that uses
     ‘vared’ for input.  If it is set to an array, the elements are
     taken to be the possible matches which will be completed using the
     tag ‘values’ and the description ‘value’.  If it is set to an
     associative array, the keys are used as the possible completions
     and the values (if non-empty) are used as descriptions for the
     matches.  If ‘compcontext’ is set to a string containing colons, it
     should be of the form TAG‘:’DESCR‘:’ACTION.  In this case the TAG
     and DESCR give the tag and description to use and the ACTION
     indicates what should be completed in one of the forms accepted by
     the ‘_arguments’ utility function described below.

     Finally, if ‘compcontext’ is set to a string without colons, the
     value is taken as the name of the context to use and the function
     defined for that context will be called.  For this purpose, there
     is a special context named ‘-command-line-’ that completes whole
     command lines (commands and their arguments).  This is not used by
     the completion system itself but is nonetheless handled when
     explicitly called.

‘_correct’

     Generate corrections, but not completions, for the current word;
     this is similar to ‘_approximate’ but will not allow any number of
     extra characters at the cursor as that completer does.  The effect
     is similar to spell-checking.  It is based on ‘_approximate’, but
     the completer field in the context name is ‘correct’.

     For example, with:

           zstyle ':completion:::::' completer \
                  _complete _correct _approximate
           zstyle ':completion:*:correct:::' max-errors 2 not-numeric
           zstyle ':completion:*:approximate:::' max-errors 3 numeric

     correction will accept up to two errors.  If a numeric argument is
     given, correction will not be performed, but correcting completion
     will be, and will accept as many errors as given by the numeric
     argument.  Without a numeric argument, first correction and then
     correcting completion will be tried, with the first one accepting
     two errors and the second one accepting three errors.

     When ‘_correct’ is called as a function, the number of errors to
     accept may be given following the ‘-a’ option.  The argument is in
     the same form a values to the ‘accept’ style, all in one string.

     This completer function is intended to be used without the
     ‘_approximate’ completer or, as in the example, just before it.
     Using it after the ‘_approximate’ completer is useless since
     ‘_approximate’ will at least generate the corrected strings
     generated by the ‘_correct’ completer – and probably more.

‘_expand’

     This completer function does not really perform completion, but
     instead checks if the word on the command line is eligible for
     expansion and, if it is, gives detailed control over how this
     expansion is done.  For this to happen, the completion system needs
     to be invoked with ‘complete-word’, not ‘expand-or-complete’ (the
     default binding for ‘TAB’), as otherwise the string will be
     expanded by the shell’s internal mechanism before the completion
     system is started.  Note also this completer should be called
     before the ‘_complete’ completer function.

     The tags used when generating expansions are ‘all-expansions’ for
     the string containing all possible expansions, ‘expansions’ when
     adding the possible expansions as single matches and ‘original’
     when adding the original string from the line.  The order in which
     these strings are generated, if at all, can be controlled by the
     ‘group-order’ and ‘tag-order’ styles, as usual.

     The format string for ‘all-expansions’ and for ‘expansions’ may
     contain the sequence ‘%o’ which will be replaced by the original
     string from the line.

     The kind of expansion to be tried is controlled by the
     ‘substitute’, ‘glob’ and ‘subst-globs-only’ styles.

     It is also possible to call ‘_expand’ as a function, in which case
     the different modes may be selected with options: ‘-s’ for
     ‘substitute’, ‘-g’ for ‘glob’ and ‘-o’ for ‘subst-globs-only’.

‘_expand_alias’

     If the word the cursor is on is an alias, it is expanded and no
     other completers are called.  The types of aliases which are to be
     expanded can be controlled with the styles ‘regular’, ‘global’ and
     ‘disabled’.

     This function is also a bindable command, see *note Bindable
     Commands: f8.

‘_extensions’

     If the cursor follows the string ‘*.’, filename extensions are
     completed.  The extensions are taken from files in current
     directory or a directory specified at the beginning of the current
     word.  For exact matches, completion continues to allow other
     completers such as ‘_expand’ to expand the pattern.  The standard
     ‘add-space’ and ‘prefix-hidden’ styles are observed.

‘_external_pwds’

     Completes current directories of other zsh processes belonging to
     the current user.

     This is intended to be used via ‘_generic’, bound to a custom key
     combination.  Note that pattern matching is enabled so matching is
     performed similar to how it works with the ‘_match’ completer.

‘_history’

     Complete words from the shell’s command history.  This completer
     can be controlled by the ‘remove-all-dups’, and ‘sort’ styles as
     for the ‘_history_complete_word’ bindable command, see *note
     Bindable Commands: f8. and *note Completion System Configuration:
     f1.

‘_ignored’

     The ‘ignored-patterns’ style can be set to a list of patterns which
     are compared against possible completions; matching ones are
     removed.  With this completer those matches can be reinstated, as
     if no ‘ignored-patterns’ style were set.  The completer actually
     generates its own list of matches; which completers are invoked is
     determined in the same way as for the ‘_prefix’ completer.  The
     ‘single-ignored’ style is also available as described above.

‘_list’

     This completer allows the insertion of matches to be delayed until
     completion is attempted a second time without the word on the line
     being changed.  On the first attempt, only the list of matches will
     be shown.  It is affected by the styles ‘condition’ and ‘word’, see
     *note Completion System Configuration: f1.

‘_match’

     This completer is intended to be used after the ‘_complete’
     completer.  It behaves similarly but the string on the command line
     may be a pattern to match against trial completions.  This gives
     the effect of the ‘GLOB_COMPLETE’ option.

     Normally completion will be performed by taking the pattern from
     the line, inserting a ‘*’ at the cursor position and comparing the
     resulting pattern with the possible completions generated.  This
     can be modified with the ‘match-original’ style described above.

     The generated matches will be offered in a menu completion unless
     the ‘insert-unambiguous’ style is set to ‘true’; see the
     description above for other options for this style.

     Note that matcher specifications defined globally or used by the
     completion functions (the styles ‘matcher-list’ and ‘matcher’) will
     not be used.

‘_menu’

     This completer was written as simple example function to show how
     menu completion can be enabled in shell code.  However, it has the
     notable effect of disabling menu selection which can be useful with
     ‘_generic’ based widgets.  It should be used as the first completer
     in the list.  Note that this is independent of the setting of the
     ‘MENU_COMPLETE’ option and does not work with the other menu
     completion widgets such as ‘reverse-menu-complete’, or
     ‘accept-and-menu-complete’.

‘_oldlist’

     This completer controls how the standard completion widgets behave
     when there is an existing list of completions which may have been
     generated by a special completion (i.e.  a separately-bound
     completion command).  It allows the ordinary completion keys to
     continue to use the list of completions thus generated, instead of
     producing a new list of ordinary contextual completions.  It should
     appear in the list of completers before any of the widgets which
     generate matches.  It uses two styles: ‘old-list’ and ‘old-menu’,
     see *note Completion System Configuration: f1.

‘_precommand’

     Complete an external command in word-separated arguments, as for
     ‘exec’ and ‘/usr/bin/env’.

‘_prefix’

     This completer can be used to try completion with the suffix
     (everything after the cursor) ignored.  In other words, the suffix
     will not be considered to be part of the word to complete.  The
     effect is similar to the ‘expand-or-complete-prefix’ command.

     The ‘completer’ style is used to decide which other completers are
     to be called to generate matches.  If this style is unset, the list
     of completers set for the current context is used – except, of
     course, the ‘_prefix’ completer itself.  Furthermore, if this
     completer appears more than once in the list of completers only
     those completers not already tried by the last invocation of
     ‘_prefix’ will be called.

     For example, consider this global ‘completer’ style:

           zstyle ':completion:*' completer \
               _complete _prefix _correct _prefix:foo

     Here, the ‘_prefix’ completer tries normal completion but ignoring
     the suffix.  If that doesn’t generate any matches, and neither does
     the call to the ‘_correct’ completer after it, ‘_prefix’ will be
     called a second time and, now only trying correction with the
     suffix ignored.  On the second invocation the completer part of the
     context appears as ‘foo’.

     To use ‘_prefix’ as the last resort and try only normal completion
     when it is invoked:

           zstyle ':completion:*' completer _complete ... _prefix
           zstyle ':completion::prefix:*' completer _complete

     The ‘add-space’ style is also respected.  If it is set to ‘true’
     then ‘_prefix’ will insert a space between the matches generated
     (if any) and the suffix.

     Note that this completer is only useful if the ‘COMPLETE_IN_WORD’
     option is set; otherwise, the cursor will be moved to the end of
     the current word before the completion code is called and hence
     there will be no suffix.

‘_user_expand’

     This completer behaves similarly to the ‘_expand’ completer but
     instead performs expansions defined by users.  The styles
     ‘add-space’ and ‘sort’ styles specific to the ‘_expand’ completer
     are usable with ‘_user_expand’ in addition to other styles handled
     more generally by the completion system.  The tag ‘all-expansions’
     is also available.

     The expansion depends on the array style ‘user-expand’ being
     defined for the current context; remember that the context for
     completers is less specific than that for contextual completion as
     the full context has not yet been determined.  Elements of the
     array may have one of the following forms:

     ‘$’HASH

          HASH is the name of an associative array.  Note this is not a
          full parameter expression, merely a ‘$’, suitably quoted to
          prevent immediate expansion, followed by the name of an
          associative array.  If the trial expansion word matches a key
          in HASH, the resulting expansion is the corresponding value.

     _FUNC

          _FUNC is the name of a shell function whose name must begin
          with ‘_’ but is not otherwise special to the completion
          system.  The function is called with the trial word as an
          argument.  If the word is to be expanded, the function should
          set the array ‘reply’ to a list of expansions.  Optionally, it
          can set ‘REPLY’ to a word that will be used as a description
          for the set of expansions.  The return status of the function
          is irrelevant.


File: zsh.info,  Node: Bindable Commands,  Next: Utility Functions,  Prev: Control Functions,  Up: Completion System

19.5 Bindable Commands
======================

In addition to the context-dependent completions provided, which are
expected to work in an intuitively obvious way, there are a few widgets
implementing special behaviour which can be bound separately to keys.
The following is a list of these and their default bindings.

‘_bash_completions’

     This function is used by two widgets, ‘_bash_complete-word’ and
     ‘_bash_list-choices’.  It exists to provide compatibility with
     completion bindings in bash.  The last character of the binding
     determines what is completed: ‘!’, command names; ‘$’, environment
     variables; ‘@’, host names; ‘/’, file names; ‘~’ user names.  In
     bash, the binding preceded by ‘\e’ gives completion, and preceded
     by ‘^X’ lists options.  As some of these bindings clash with
     standard zsh bindings, only ‘\e~’ and ‘^X~’ are bound by default.
     To add the rest, the following should be added to ‘.zshrc’ after
     ‘compinit’ has been run:

           for key in '!' '$' '@' '/' '~'; do
             bindkey "\e$key" _bash_complete-word
             bindkey "^X$key" _bash_list-choices
           done

     This includes the bindings for ‘~’ in case they were already bound
     to something else; the completion code does not override user
     bindings.

‘_correct_filename’ (‘^XC’)

     Correct the filename path at the cursor position.  Allows up to six
     errors in the name.  Can also be called with an argument to correct
     a filename path, independently of zle; the correction is printed on
     standard output.

‘_correct_word’ (‘^Xc’)

     Performs correction of the current argument using the usual
     contextual completions as possible choices.  This stores the string
     ‘correct-word’ in the FUNCTION field of the context name and then
     calls the ‘_correct’ completer.

‘_expand_alias’ (‘^Xa’)

     This function can be used as a completer and as a bindable command.
     It expands the word the cursor is on if it is an alias.  The types
     of alias expanded can be controlled with the styles ‘regular’,
     ‘global’ and ‘disabled’.

     When used as a bindable command there is one additional feature
     that can be selected by setting the ‘complete’ style to ‘true’.  In
     this case, if the word is not the name of an alias, ‘_expand_alias’
     tries to complete the word to a full alias name without expanding
     it.  It leaves the cursor directly after the completed word so that
     invoking ‘_expand_alias’ once more will expand the now-complete
     alias name.

‘_expand_word’ (‘^Xe’)

     Performs expansion on the current word: equivalent to the standard
     ‘expand-word’ command, but using the ‘_expand’ completer.  Before
     calling it, the FUNCTION field of the context is set to
     ‘expand-word’.

‘_generic’

     This function is not defined as a widget and not bound by default.
     However, it can be used to define a widget and will then store the
     name of the widget in the FUNCTION field of the context and call
     the completion system.  This allows custom completion widgets with
     their own set of style settings to be defined easily.  For example,
     to define a widget that performs normal completion and starts menu
     selection:

           zle -C foo complete-word _generic
           bindkey '...' foo
           zstyle ':completion:foo:*' menu yes select=1

     Note in particular that the ‘completer’ style may be set for the
     context in order to change the set of functions used to generate
     possible matches.  If ‘_generic’ is called with arguments, those
     are passed through to ‘_main_complete’ as the list of completers in
     place of those defined by the ‘completer’ style.

‘_history_complete_word’ (‘\e/’)

     Complete words from the shell’s command history.  This uses the
     ‘list’, ‘remove-all-dups’, ‘sort’, and ‘stop’ styles.

‘_most_recent_file’ (‘^Xm’)

     Complete the name of the most recently modified file matching the
     pattern on the command line (which may be blank).  If given a
     numeric argument N, complete the Nth most recently modified file.
     Note the completion, if any, is always unique.

‘_next_tags’ (‘^Xn’)

     This command alters the set of matches used to that for the next
     tag, or set of tags, either as given by the ‘tag-order’ style or as
     set by default; these matches would otherwise not be available.
     Successive invocations of the command cycle through all possible
     sets of tags.

‘_read_comp’ (‘^X^R’)

     Prompt the user for a string, and use that to perform completion on
     the current word.  There are two possibilities for the string.
     First, it can be a set of words beginning ‘_’, for example ‘_files
     -/’, in which case the function with any arguments will be called
     to generate the completions.  Unambiguous parts of the function
     name will be completed automatically (normal completion is not
     available at this point) until a space is typed.

     Second, any other string will be passed as a set of arguments to
     ‘compadd’ and should hence be an expression specifying what should
     be completed.

     A very restricted set of editing commands is available when reading
     the string: ‘DEL’ and ‘^H’ delete the last character; ‘^U’ deletes
     the line, and ‘^C’ and ‘^G’ abort the function, while ‘RET’ accepts
     the completion.  Note the string is used verbatim as a command
     line, so arguments must be quoted in accordance with standard shell
     rules.

     Once a string has been read, the next call to ‘_read_comp’ will use
     the existing string instead of reading a new one.  To force a new
     string to be read, call ‘_read_comp’ with a numeric argument.

‘_complete_debug’ (‘^X?’)

     This widget performs ordinary completion, but captures in a
     temporary file a trace of the shell commands executed by the
     completion system.  Each completion attempt gets its own file.  A
     command to view each of these files is pushed onto the editor
     buffer stack.

‘_complete_help’ (‘^Xh’)

     This widget displays information about the context names, the tags,
     and the completion functions used when completing at the current
     cursor position.  If given a numeric argument other than ‘1’ (as in
     ‘ESC-2 ^Xh’), then the styles used and the contexts for which they
     are used will be shown, too.

     Note that the information about styles may be incomplete; it
     depends on the information available from the completion functions
     called, which in turn is determined by the user’s own styles and
     other settings.

‘_complete_help_generic’

     Unlike other commands listed here, this must be created as a normal
     ZLE widget rather than a completion widget (i.e.  with ‘zle -N’).
     It is used for generating help with a widget bound to the
     ‘_generic’ widget that is described above.

     If this widget is created using the name of the function, as it is
     by default, then when executed it will read a key sequence.  This
     is expected to be bound to a call to a completion function that
     uses the ‘_generic’ widget.  That widget will be executed, and
     information provided in the same format that the ‘_complete_help’
     widget displays for contextual completion.

     If the widget’s name contains ‘debug’, for example if it is created
     as ‘zle -N _complete_debug_generic _complete_help_generic’, it will
     read and execute the keystring for a generic widget as before, but
     then generate debugging information as done by ‘_complete_debug’
     for contextual completion.

     If the widget’s name contains ‘noread’, it will not read a
     keystring but instead arrange that the next use of a generic widget
     run in the same shell will have the effect as described above.

     The widget works by setting the shell parameter
     ‘ZSH_TRACE_GENERIC_WIDGET’ which is read by ‘_generic’.  Unsetting
     the parameter cancels any pending effect of the ‘noread’ form.

     For example, after executing the following:

           zle -N _complete_debug_generic _complete_help_generic
           bindkey '^x:' _complete_debug_generic

     typing ‘C-x :’ followed by the key sequence for a generic widget
     will cause trace output for that widget to be saved to a file.

‘_complete_tag’ (‘^Xt’)

     This widget completes symbol tags created by the ‘etags’ or ‘ctags’
     programmes (note there is no connection with the completion
     system’s tags) stored in a file ‘TAGS’, in the format used by
     ‘etags’, or ‘tags’, in the format created by ‘ctags’.  It will look
     back up the path hierarchy for the first occurrence of either file;
     if both exist, the file ‘TAGS’ is preferred.  You can specify the
     full path to a ‘TAGS’ or ‘tags’ file by setting the parameter
     ‘$TAGSFILE’ or ‘$tagsfile’ respectively.  The corresponding
     completion tags used are ‘etags’ and ‘vtags’, after emacs and vi
     respectively.


File: zsh.info,  Node: Utility Functions,  Next: Completion System Variables,  Prev: Bindable Commands,  Up: Completion System

19.6 Utility Functions
======================

Descriptions follow for utility functions that may be useful when
writing completion functions.  If functions are installed in
subdirectories, most of these reside in the ‘Base’ subdirectory.  Like
the example functions for commands in the distribution, the utility
functions generating matches all follow the convention of returning
status zero if they generated completions and non-zero if no matching
completions could be added.

‘_absolute_command_paths’

     This function completes external commands as absolute paths (unlike
     ‘_command_names -e’ which completes their basenames).  It takes no
     arguments.

‘_all_labels’ [ ‘-x’ ] [ ‘-12VJ’ ] TAG NAME DESCR [ COMMAND ARG … ]

     This is a convenient interface to the ‘_next_label’ function below,
     implementing the loop shown in the ‘_next_label’ example.  The
     COMMAND and its arguments are called to generate the matches.  The
     options stored in the parameter NAME will automatically be inserted
     into the ARGs passed to the COMMAND.  Normally, they are put
     directly after the COMMAND, but if one of the ARGs is a single
     hyphen, they are inserted directly before that.  If the hyphen is
     the last argument, it will be removed from the argument list before
     the COMMAND is called.  This allows ‘_all_labels’ to be used in
     almost all cases where the matches can be generated by a single
     call to the ‘compadd’ builtin command or by a call to one of the
     utility functions.

     For example:

           local expl
           ...
           if _requested foo; then
             ...
             _all_labels foo expl '...' compadd ... - $matches
           fi

     Will complete the strings from the ‘matches’ parameter, using
     ‘compadd’ with additional options which will take precedence over
     those generated by ‘_all_labels’.

‘_alternative’ [ ‘-O’ NAME ] [ ‘-C’ NAME ] SPEC …

     This function is useful in simple cases where multiple tags are
     available.  Essentially it implements a loop like the one described
     for the ‘_tags’ function below.

     The tags to use and the action to perform if a tag is requested are
     described using the SPECs which are of the form:
     TAG‘:’DESCR‘:’ACTION.  The TAGs are offered using ‘_tags’ and if
     the tag is requested, the ACTION is executed with the given
     description DESCR.  The ACTIONs are those accepted by the
     ‘_arguments’ function (described below), with the following
     exceptions:

             * The ‘->’STATE and ‘=’… forms are not supported.

             * The ‘((a\:bar b\:baz))’ form does not need

          the colon to be escaped, since the SPECs have no
          colon-separated fields after the ACTION.

     For example, the ACTION may be a simple function call:

           _alternative \
               'users:user:_users' \
               'hosts:host:_hosts'

     offers usernames and hostnames as possible matches, generated by
     the ‘_users’ and ‘_hosts’ functions respectively.

     Like ‘_arguments’, this function uses ‘_all_labels’ to execute the
     actions, which will loop over all sets of tags.  Special handling
     is only required if there is an additional valid tag, for example
     inside a function called from ‘_alternative’.

     The option ‘-O’ NAME is used in the same way as by the ‘_arguments’
     function.  In other words, the elements of the NAME array will be
     passed to ‘compadd’ when executing an action.

     Like ‘_tags’ this function supports the ‘-C’ option to give a
     different name for the argument context field.

‘_arguments’ [ ‘-nswWCRS’ ] [ ‘-A’ PAT ] [ ‘-O’ NAME ] [ ‘-M’ MATCHSPEC
]

     [ ‘:’ ] SPEC …

‘_arguments’ [ OPT … ] ‘--’ [ ‘-l’ ] [ ‘-i’ PATS ] [ ‘-s’ PAIR ]

          [ HELPSPEC …]

     This function can be used to give a complete specification for
     completion for a command whose arguments follow standard UNIX
     option and argument conventions.

     ‘Options Overview’

     Options to ‘_arguments’ itself must be in separate words, i.e.  ‘-s
     -w’, not ‘-sw’.  The options are followed by SPECs that describe
     options and arguments of the analyzed command.  To avoid ambiguity,
     all options to ‘_arguments’ itself may be separated from the SPEC
     forms by a single colon.

     The ‘--’ form is used to intuit SPEC forms from the help output of
     the command being analyzed, and is described in detail below.  The
     OPTS for the ‘--’ form are otherwise the same options as the first
     form.  Note that ‘-s’ following ‘--’ has a distinct meaning from
     ‘-s’ preceding ‘--’, and both may appear.

     The option switches ‘-s’, ‘-S’, ‘-A’, ‘-w’, and ‘-W’ affect how
     ‘_arguments’ parses the analyzed command line’s options.  These
     switches are useful for commands with standard argument parsing.

     The options of ‘_arguments’ have the following meanings:

     ‘-n’

          With this option, ‘_arguments’ sets the parameter ‘NORMARG’ to
          the position of the first normal argument in the ‘$words’
          array, i.e.  the position after the end of the options.  If
          that argument has not been reached, ‘NORMARG’ is set to ‘-1’.
          The caller should declare ‘integer NORMARG’ if the ‘-n’ option
          is passed; otherwise the parameter is not used.

     ‘-s’

          Enable ‘option stacking’ for single-letter options, whereby
          multiple single-letter options may be combined into a single
          word.  For example, the two options ‘-x’ and ‘-y’ may be
          combined into a single word ‘-xy’.  By default, every word
          corresponds to a single option name (‘-xy’ is a single option
          named ‘xy’).

          Options beginning with a single hyphen or plus sign are
          eligible for stacking; words beginning with two hyphens are
          not.

          Note that ‘-s’ after ‘--’ has a different meaning, which is
          documented in the segment entitled Deriving SPEC forms from
          the help output.

     ‘-w’

          In combination with ‘-s’, allow option stacking even if one or
          more of the options take arguments.  For example, if ‘-x’
          takes an argument, with no ‘-s’, ‘-xy’ is considered as a
          single (unhandled) option; with ‘-s’, ‘-xy’ is an option with
          the argument ‘y’; with both ‘-s’ and ‘-w’, ‘-xy’ is the option
          ‘-x’ and the option ‘-y’ with arguments to ‘-x’ (and to ‘-y’,
          if it takes arguments) still to come in subsequent words.

     ‘-W’

          This option takes ‘-w’ a stage further: it is possible to
          complete single-letter options even after an argument that
          occurs in the same word.  However, it depends on the action
          performed whether options will really be completed at this
          point.  For more control, use a utility function like ‘_guard’
          as part of the action.

     ‘-C’

          Modify the ‘curcontext’ parameter for an action of the form
          ‘->’STATE.  This is discussed in detail below.

     ‘-R’

          Return status 300 instead of zero when a ‘$state’ is to be
          handled, in the ‘->’STRING syntax.

     ‘-S’

          Do not complete options after a ‘--’ appearing on the line,
          and ignore the ‘--’.  For example, with ‘-S’, in the line

                foobar -x -- -y

          the ‘-x’ is considered an option, the ‘-y’ is considered an
          argument, and the ‘--’ is considered to be neither.

          If this option is given twice (as ‘-S -S’), a single ‘-’ is
          also treated this way.  This is useful for completing zsh’s
          own builtins as well as functions that use ‘zparseopts’ for
          option parsing.

     ‘-A’ PAT

          Do not complete options after the first non-option argument on
          the line.  PAT is a pattern matching all strings which are not
          to be taken as arguments.  For example, to make ‘_arguments’
          stop completing options after the first normal argument, but
          ignoring all strings starting with a hyphen even if they are
          not described by one of the OPTSPECs, the form is ‘-A "-*"’.

     ‘-O’ NAME

          Pass the elements of the array NAME as arguments to functions
          called to execute ACTIONs.  This is discussed in detail below.

     ‘-M’ MATCHSPEC

          Use the match specification MATCHSPEC for completing option
          names and values.  The default MATCHSPEC allows partial word
          completion after ‘_’ and ‘-’, such as completing ‘-f-b’ to
          ‘-foo-bar’.  The default MATCHSPEC is:

                r:|[_-]=* r:|=*

     ‘-0’

          When populating values of the ‘opt_args’ associative array,
          don’t backslash-escape colons and backslashes and use NUL
          rather than colon for joining multiple values.  This option is
          described in more detail below, under the heading
          ‘:var:’spec‘s: actions‘.

     ‘:var:’spec‘s: overview‘

     Each of the following forms is a SPEC describing individual sets of
     options or arguments on the command line being analyzed.

     N‘:’MESSAGE‘:’ACTION

     N‘::’MESSAGE‘:’ACTION

          This describes the N’th normal argument.  The MESSAGE will be
          printed above the matches generated and the ACTION indicates
          what can be completed in this position (see below).  If there
          are two colons before the MESSAGE the argument is optional.
          If the MESSAGE contains only white space, nothing will be
          printed above the matches unless the action adds an
          explanation string itself.

     ‘:’MESSAGE‘:’ACTION

     ‘::’MESSAGE‘:’ACTION

          Similar, but describes the ‘next’ argument, whatever number
          that happens to be.  If all arguments are specified in this
          form in the correct order the numbers are unnecessary.

     ‘*:’MESSAGE‘:’ACTION

     ‘*::’MESSAGE‘:’ACTION

     ‘*:::’MESSAGE‘:’ACTION

          This describes how arguments (usually non-option arguments,
          those not beginning with ‘-’ or ‘+’) are to be completed when
          neither of the first two forms was provided.  Any number of
          arguments can be completed in this fashion.

          With two colons before the MESSAGE, the ‘words’ special array
          and the ‘CURRENT’ special parameter are modified to refer only
          to the normal arguments when the ACTION is executed or
          evaluated.  With three colons before the MESSAGE they are
          modified to refer only to the normal arguments covered by this
          description.

     OPTSPEC

     OPTSPEC‘:’…

          This describes an option.  The colon indicates handling for
          one or more arguments to the option; if it is not present, the
          option is assumed to take no arguments.

          The following forms are available for the initial OPTSPEC,
          whether or not the option has arguments.

          ‘*’OPTSPEC

               Here OPTSPEC is one of the remaining forms below.  This
               indicates the following OPTSPEC may be repeated.
               Otherwise if the corresponding option is already present
               on the command line to the left of the cursor it will not
               be offered again.

          ‘-’OPTNAME

          ‘+’OPTNAME

               In the simplest form the OPTSPEC is just the option name
               beginning with a minus or a plus sign, such as ‘-foo’.
               The first argument for the option (if any) must follow as
               a ‘separate’ word directly after the option.

               Either of ‘-+’OPTNAME and ‘+-’OPTNAME can be used to
               specify that ‘-’OPTNAME and ‘+’OPTNAME are both valid.

               In all the remaining forms, the leading ‘-’ may be
               replaced by or paired with ‘+’ in this way.

          ‘-’OPTNAME‘-’

               The first argument of the option must come directly after
               the option name ‘in the same word’.  For example,
               ‘-foo-:’… specifies that the completed option and
               argument will look like ‘-foo’ARG.

          ‘-’OPTNAME‘+’

               The first argument may appear immediately after OPTNAME
               in the same word, or may appear as a separate word after
               the option.  For example, ‘-foo+:’… specifies that the
               completed option and argument will look like either
               ‘-foo’ARG or ‘-foo’ ARG.

          ‘-’OPTNAME‘=’

               The argument may appear as the next word, or in same word
               as the option name provided that it is separated from it
               by an equals sign, for example ‘-foo=’ARG or ‘-foo’ ARG.

          ‘-’OPTNAME‘=-’

               The argument to the option must appear after an equals
               sign in the same word, and may not be given in the next
               argument.

          OPTSPEC‘[’EXPLANATION‘]’

               An explanation string may be appended to any of the
               preceding forms of OPTSPEC by enclosing it in brackets,
               as in ‘-q[query operation]’.

               The ‘verbose’ style is used to decide whether the
               explanation strings are displayed with the option in a
               completion listing.

               If no bracketed explanation string is given but the
               ‘auto-description’ style is set and only one argument is
               described for this OPTSPEC, the value of the style is
               displayed, with any appearance of the sequence ‘%d’ in it
               replaced by the MESSAGE of the first OPTARG that follows
               the OPTSPEC; see below.

          It is possible for options with a literal ‘+’ or ‘=’ to
          appear, but that character must be quoted, for example ‘-\+’.

          Each OPTARG following an OPTSPEC must take one of the
          following forms:

          ‘:’MESSAGE‘:’ACTION

          ‘::’MESSAGE‘:’ACTION

               An argument to the option; MESSAGE and ACTION are treated
               as for ordinary arguments.  In the first form, the
               argument is mandatory, and in the second form it is
               optional.

               This group may be repeated for options which take
               multiple arguments.  In other words,
               ‘:’MESSAGE1‘:’ACTION1‘:’MESSAGE2‘:’ACTION2 specifies that
               the option takes two arguments.

          ‘:*’PATTERN‘:’MESSAGE‘:’ACTION

          ‘:*’PATTERN‘::’MESSAGE‘:’ACTION

          ‘:*’PATTERN‘:::’MESSAGE‘:’ACTION

               This describes multiple arguments.  Only the last OPTARG
               for an option taking multiple arguments may be given in
               this form.  If the PATTERN is empty (i.e.  ‘:*:’), all
               the remaining words on the line are to be completed as
               described by the ACTION; otherwise, all the words up to
               and including a word matching the PATTERN are to be
               completed using the ACTION.

               Multiple colons are treated as for the ‘*:’… forms for
               ordinary arguments: when the MESSAGE is preceded by two
               colons, the ‘words’ special array and the ‘CURRENT’
               special parameter are modified during the execution or
               evaluation of the ACTION to refer only to the words after
               the option.  When preceded by three colons, they are
               modified to refer only to the words covered by this
               description.

     Any literal colon in an OPTNAME, MESSAGE, or ACTION must be
     preceded by a backslash, ‘\:’.

     Each of the forms above may be preceded by a list in parentheses of
     option names and argument numbers.  If the given option is on the
     command line, the options and arguments indicated in parentheses
     will not be offered.  For example, ‘(-two -three 1)-one:’…
     completes the option ‘-one’; if this appears on the command line,
     the options ‘-two’ and ‘-three’ and the first ordinary argument
     will not be completed after it.  ‘(-foo):’… specifies an ordinary
     argument completion; ‘-foo’ will not be completed if that argument
     is already present.

     Other items may appear in the list of excluded options to indicate
     various other items that should not be applied when the current
     specification is matched: a single star (‘*’) for the rest
     arguments (i.e.  a specification of the form ‘*:’…); a colon (‘:’)
     for all normal (non-option-) arguments; and a hyphen (‘-’) for all
     options.  For example, if ‘(*)’ appears before an option and the
     option appears on the command line, the list of remaining arguments
     (those shown in the above table beginning with ‘*:’) will not be
     completed.

     To aid in reuse of specifications, it is possible to precede any of
     the forms above with ‘!’; then the form will no longer be
     completed, although if the option or argument appears on the
     command line they will be skipped as normal.  The main use for this
     is when the arguments are given by an array, and ‘_arguments’ is
     called repeatedly for more specific contexts: on the first call
     ‘_arguments $global_options’ is used, and on subsequent calls
     ‘_arguments !$^global_options’.

     ‘:var:’spec‘s: actions‘

     In each of the forms above the ACTION determines how completions
     should be generated.  Except for the ‘->’STRING form below, the
     ACTION will be executed by calling the ‘_all_labels’ function to
     process all tag labels.  No special handling of tags is needed
     unless a function call introduces a new one.

     The functions called to execute ACTIONs will be called with the
     elements of the array named by the ‘-O’ NAME option as arguments.
     This can be used, for example, to pass the same set of options for
     the ‘compadd’ builtin to all ACTIONs.

     The forms for ACTION are as follows.

          (single unquoted space)

               This is useful where an argument is required but it is
               not possible or desirable to generate matches for it.
               The MESSAGE will be displayed but no completions listed.
               Note that even in this case the colon at the end of the
               MESSAGE is needed; it may only be omitted when neither a
               MESSAGE nor an ACTION is given.

     ‘(’ITEM1 ITEM2 …‘)’

          One of a list of possible matches, for example:

                :foo:(foo bar baz)

     ‘((:var:`item1`\::var:`desc1` :var:`...`))’

          Similar to the above, but with descriptions for each possible
          match.  Note the backslash before the colon.  For example,

                :foo:((a\:bar b\:baz))

          The matches will be listed together with their descriptions if
          the ‘description’ style is set with the ‘values’ tag in the
          context.

     ‘->’STRING

          In this form, ‘_arguments’ processes the arguments and options
          and then returns control to the calling function with
          parameters set to indicate the state of processing; the
          calling function then makes its own arrangements for
          generating completions.  For example, functions that implement
          a state machine can use this type of action.

          Where ‘_arguments’ encounters ACTION in the ‘->’STRING format,
          it will strip all leading and trailing whitespace from STRING
          and set the array ‘state’ to the set of all STRINGs for which
          an action is to be performed.  The elements of the array
          ‘state_descr’ are assigned the corresponding MESSAGE field
          from each OPTARG containing such an ACTION.

          By default and in common with all other well behaved
          completion functions, _arguments returns status zero if it was
          able to add matches and non-zero otherwise.  However, if the
          ‘-R’ option is given, ‘_arguments’ will instead return a
          status of 300 to indicate that ‘$state’ is to be handled.

          In addition to ‘$state’ and ‘$state_descr’, ‘_arguments’ also
          sets the global parameters ‘context’, ‘line’ and ‘opt_args’ as
          described below, and does not reset any changes made to the
          special parameters such as ‘PREFIX’ and ‘words’.  This gives
          the calling function the choice of resetting these parameters
          or propagating changes in them.

          A function calling ‘_arguments’ with at least one action
          containing a ‘->’STRING must therefore declare appropriate
          local parameters:

                local context state state_descr line
                typeset -A opt_args

          to prevent ‘_arguments’ from altering the global environment.

     ‘{’EVAL-STRING‘}’

          A string in braces is evaluated as shell code to generate
          matches.  This is similar to the WORD … action described
          below, but isn’t limited to a single command.

     ‘=’ ACTION

               If the ACTION starts with ‘=’ (an equals sign followed by
               a space), ‘_arguments’ will insert the contents of the
               ARGUMENT field of the current context as the new first
               element in the ‘words’ special array and increment the
               value of the ‘CURRENT’ special parameter.  This has the
               effect of inserting a dummy word onto the completion
               command line while not changing the point at which
               completion is taking place.

               This is most useful with one of the specifiers that
               restrict the words on the command line on which the
               ACTION is to operate (the two- and three-colon forms
               above).  One particular use is when an ACTION itself
               causes ‘_arguments’ on a restricted range; it is
               necessary to use this trick to insert an appropriate
               command name into the range for the second call to
               ‘_arguments’ to be able to parse the line.

          WORD …

     WORD …

          This covers all forms other than those above.  If the ACTION
          starts with a space, the remaining list of words will be
          invoked unchanged.

          Otherwise it will be invoked with some extra strings placed
          after the first word; these are to be passed down as options
          to the ‘compadd’ builtin.  They ensure that the state
          specified by ‘_arguments’, in particular the descriptions of
          options and arguments, is correctly passed to the completion
          command.  These additional arguments are taken from the array
          parameter ‘expl’; this will be set up before executing the
          ACTION and hence may be referred to inside it, typically in an
          expansion of the form ‘$expl[@]’ which preserves empty
          elements of the array.

     During the performance of the action the array ‘line’ will be set
     to the normal arguments from the command line, i.e.  the words from
     the command line after the command name excluding all options and
     their arguments.  Also excluded are any words appearing after the
     current word, the parsing terminator ‘--’ or ‘-’ if ‘_arguments’
     was called with ‘-S’, and any words ignored by the ‘-A’ pattern.

     Options are stored in the associative array ‘opt_args’ with option
     names as keys and their arguments as the values.  By default, all
     colons and backslashes in the value are escaped with backslashes,
     and if an option has multiple arguments (for example, when using an
     OPTSPEC of the form ‘*’OPTSPEC), they are joined with (unescaped)
     colons.  However, if the ‘-0’ option was passed, no backslash
     escaping is performed, and multiple values are joined with NUL
     bytes.  For example, after ‘zsh -o foo:foo -o bar:bar -o <TAB>’,
     the contents of ‘opt_args’ would be

           typeset -A opt_args=( [-o]='foo\:foo:bar\:bar:' )

     by default, and

           typeset -A opt_args=( [-o]=$'foo:foo\x00bar:bar\x00' )

     if ‘_arguments’ had been called with the ‘-0’ option.

     The parameter ‘context’ is set when returning to the calling
     function to perform an action of the form ‘->’STRING.  It is set to
     an array of elements corresponding to the elements of ‘$state’.
     Each element is a suitable name for the argument field of the
     context: either a string of the form ‘option’-OPT‘-’N for the N’th
     argument of the option -OPT, or a string of the form ‘argument-’N
     for the N’th argument.  For ‘rest’ arguments, that is those in the
     list at the end not handled by position, N is the string ‘rest’.
     For example, when completing the argument of the ‘-o’ option, the
     name is ‘option-o-1’, while for the second normal (non-option-)
     argument it is ‘argument-2’.

     Furthermore, during the evaluation of the ACTION the context name
     in the ‘curcontext’ parameter is altered to append the same string
     that is stored in the ‘context’ parameter.

     The option ‘-C’ tells ‘_arguments’ to modify the ‘curcontext’
     parameter for an action of the form ‘->’STATE.  This is the
     standard parameter used to keep track of the current context.  Here
     it (and not the ‘context’ array) should be made local to the
     calling function to avoid passing back the modified value and
     should be initialised to the current value at the start of the
     function:

           local curcontext="$curcontext"

     This is useful where it is not possible for multiple states to be
     valid together.

     ‘Grouping Options’

     Options can be grouped to simplify exclusion lists.  A group is
     introduced with ‘+’ followed by a name for the group in the
     subsequent word.  Whole groups can then be referenced in an
     exclusion list or a group name can be used to disambiguate between
     two forms of the same option.  For example:

           _arguments \
               '(group2--x)-a' \
             + group1 \
               -m \
               '(group2)-n' \
             + group2 \
               -x -y

     If the name of a group is specified in the form ‘(’NAME‘)’ then
     only one value from that group will ever be completed; more
     formally, all specifications are mutually exclusive to all other
     specifications in that group.  This is useful for defining options
     that are aliases for each other.  For example:

           _arguments \
               -a -b \
             + '(operation)' \
               {-c,--compress}'[compress]' \
               {-d,--decompress}'[decompress]' \
               {-l,--list}'[list]'

     If an option in a group appears on the command line, it is stored
     in the associative array ‘opt_args’ with ‘GROUP‘-’OPTION’ as a key.
     In the example above, a key ‘operation--c’ is used if the option
     ‘-c’ is present on the command line.

     ‘Specifying Multiple Sets of Arguments’

     It is possible to specify multiple sets of options and arguments
     with the sets separated by single hyphens.  This differs from
     groups in that sets are considered to be mutually exclusive of each
     other.

     Specifications before the first set and from any group are common
     to all sets.  For example:

           _arguments \
               -a \
             - set1 \
               -c \
             - set2 \
               -d \
               ':arg:(x2 y2)'

     This defines two sets.  When the command line contains the option
     ‘-c’, the ‘-d’ option and the argument will not be considered
     possible completions.  When it contains ‘-d’ or an argument, the
     option ‘-c’ will not be considered.  However, after ‘-a’ both sets
     will still be considered valid.

     As for groups, the name of a set may appear in exclusion lists,
     either alone or preceding a normal option or argument
     specification.

     The completion code has to parse the command line separately for
     each set.  This can be slow so sets should only be used when
     necessary.  A useful alternative is often an option specification
     with rest-arguments (as in ‘-foo:*:...’); here the option ‘-foo’
     swallows up all remaining arguments as described by the OPTARG
     definitions.

     ‘Deriving :var:’spec‘ forms from the help output‘

     The option ‘--’ allows ‘_arguments’ to work out the names of long
     options that support the ‘--help’ option which is standard in many
     GNU commands.  The command word is called with the argument
     ‘--help’ and the output examined for option names.  Clearly, it can
     be dangerous to pass this to commands which may not support this
     option as the behaviour of the command is unspecified.

     In addition to options, ‘_arguments --’ will try to deduce the
     types of arguments available for options when the form
     ‘--’OPT‘=’VAL is valid.  It is also possible to provide hints by
     examining the help text of the command and adding HELPSPEC of the
     form PATTERN‘:’MESSAGE‘:’ACTION; note that other ‘_arguments’ SPEC
     forms are not used.  The PATTERN is matched against the help text
     for an option, and if it matches the MESSAGE and ACTION are used as
     for other argument specifiers.  The special case of ‘*:’ means both
     MESSAGE and ACTION are empty, which has the effect of causing
     options having no description in the help output to be ordered in
     listings ahead of options that have a description.

     For example:

           _arguments -- '*\*:toggle:(yes no)' \
                         '*=FILE*:file:_files' \
                         '*=DIR*:directory:_files -/' \
                         '*=PATH*:directory:_files -/'

     Here, ‘yes’ and ‘no’ will be completed as the argument of options
     whose description ends in a star; file names will be completed for
     options that contain the substring ‘=FILE’ in the description; and
     directories will be completed for options whose description
     contains ‘=DIR’ or ‘=PATH’.  The last three are in fact the default
     and so need not be given explicitly, although it is possible to
     override the use of these patterns.  A typical help text which uses
     this feature is:

             -C, --directory=DIR          change to directory DIR

     so that the above specifications will cause directories to be
     completed after ‘--directory’, though not after ‘-C’.

     Note also that ‘_arguments’ tries to find out automatically if the
     argument for an option is optional.  This can be specified
     explicitly by doubling the colon before the MESSAGE.

     If the PATTERN ends in ‘(-)’, this will be removed from the pattern
     and the ACTION will be used only directly after the ‘=’, not in the
     next word.  This is the behaviour of a normal specification defined
     with the form ‘=-’.

     By default, the command (with the option ‘--help’) is run after
     resetting all the locale categories (except for ‘LC_CTYPE’) to ‘C’.
     If the localized help output is known to work, the option ‘-l’ can
     be specified after the ‘_arguments --’ so that the command is run
     in the current locale.

     The ‘_arguments --’ can be followed by the option ‘-i’ PATTERNS to
     give patterns for options which are not to be completed.  The
     patterns can be given as the name of an array parameter or as a
     literal list in parentheses.  For example,

           _arguments -- -i \
               "(--(en|dis)able-FEATURE*)"

     will cause completion to ignore the options ‘--enable-FEATURE’ and
     ‘--disable-FEATURE’ (this example is useful with GNU ‘configure’).

     The ‘_arguments --’ form can also be followed by the option ‘-s’
     PAIR to describe option aliases.  The PAIR consists of a list of
     alternating patterns and corresponding replacements, enclosed in
     parens and quoted so that it forms a single argument word in the
     ‘_arguments’ call.

     For example, some ‘configure’-script help output describes options
     only as ‘--enable-foo’, but the script also accepts the negated
     form ‘--disable-foo’.  To allow completion of the second form:

           _arguments -- -s "((#s)--enable- --disable-)"

     ‘Miscellaneous notes’

     Finally, note that ‘_arguments’ generally expects to be the primary
     function handling any completion for which it is used.  It may have
     side effects which change the treatment of any matches added by
     other functions called after it.  To combine ‘_arguments’ with
     other functions, those functions should be called either before
     ‘_arguments’, as an ACTION within a SPEC, or in handlers for
     ‘->’STATE actions.

     Here is a more general example of the use of ‘_arguments’:

           _arguments '-l+:left border:' \
                      '-format:paper size:(letter A4)' \
                      '*-copy:output file:_files::resolution:(300 600)' \
                      ':postscript file:_files -g \*.\(ps\|eps\)' \
                      '*:page number:'

     This describes three options: ‘-l’, ‘-format’, and ‘-copy’.  The
     first takes one argument described as LEFT BORDER for which no
     completion will be offered because of the empty action.  Its
     argument may come directly after the ‘-l’ or it may be given as the
     next word on the line.

     The ‘-format’ option takes one argument in the next word, described
     as PAPER SIZE for which only the strings ‘letter’ and ‘A4’ will be
     completed.

     The ‘-copy’ option may appear more than once on the command line
     and takes two arguments.  The first is mandatory and will be
     completed as a filename.  The second is optional (because of the
     second colon before the description RESOLUTION) and will be
     completed from the strings ‘300’ and ‘600’.

     The last two descriptions say what should be completed as
     arguments.  The first describes the first argument as a POSTSCRIPT
     FILE and makes files ending in ‘ps’ or ‘eps’ be completed.  The
     last description gives all other arguments the description PAGE
     NUMBER but does not offer completions.

‘_as_if’ COMMAND [ARG … ]

     This function is useful when one command should be completed as if
     it were another command with particular arguments.  For example to
     complete ‘foo’ as if it were ‘bar --baz’, use

           compdef '_as_if bar --baz' foo

‘_cache_invalid’ CACHE_IDENTIFIER

     This function returns status zero if the completions cache
     corresponding to the given cache identifier needs rebuilding.  It
     determines this by looking up the ‘cache-policy’ style for the
     current context.  This should provide a function name which is run
     with the full path to the relevant cache file as the only argument.

     Example:

           _example_caching_policy () {
               # rebuild if cache is more than a week old
               local -a oldp
               oldp=( "$1"(Nm+7) )
               (( $#oldp ))
           }

‘_call_function’ RETURN NAME [ ARG … ]

     If a function NAME exists, it is called with the arguments ARGs.
     The RETURN argument gives the name of a parameter in which the
     return status from the function NAME should be stored; if RETURN is
     empty or a single hyphen it is ignored.

     The return status of ‘_call_function’ itself is zero if the
     function NAME exists and was called and non-zero otherwise.

‘_call_program’ [ ‘-lpqQ’ ] TAG STRING …

     This function provides a mechanism for the user to override the use
     of an external command.  It looks up the ‘command’ style with the
     supplied TAG.  If the style is set, its value is used as the
     command to execute.  The STRINGs from the call to ‘_call_program’,
     or from the style if set, are concatenated with spaces between them
     and the resulting string is evaluated.  The return status is the
     return status of the command called.

     By default, the command is run in an environment where all the
     locale categories (except for ‘LC_CTYPE’) are reset to ‘C’ by
     calling the utility function ‘_comp_locale’ (see below).  If the
     option ‘-l’ is given, the command is run with the current locale.

     If the option ‘-p’ is supplied it indicates that the command output
     is influenced by the permissions it is run with.  If the
     ‘gain-privileges’ style is set to true, ‘_call_program’ will make
     use of commands such as ‘sudo’, if present on the command-line, to
     match the permissions to whatever the final command is likely to
     run under.  When looking up the ‘gain-privileges’ and ‘command’
     styles, the command component of the zstyle context will end with a
     slash (‘/’) followed by the command that would be used to gain
     privileges.

     By default, the STRINGs are passed directly to ‘eval’, which may
     require double-quoting in some cases.  The options ‘-q’ and ‘-Q’
     can help with this: with ‘-q’, all STRINGs are quoted, whereas with
     ‘-Q’ all STRINGs except the first one (usually the name of the
     command to run) are quoted.  ‘-Q’ is useful when the first STRING
     is ‘$words[1]’, which may already be quoted since it is taken
     directly from the typed command line.  These options do not affect
     the quoting of arguments derived from the ‘command’ style.

‘_combination’ [ ‘-s’ PATTERN ] TAG STYLE SPEC … FIELD OPTS …

     This function is used to complete combinations of values, for
     example pairs of hostnames and usernames.  The STYLE argument gives
     the style which defines the pairs; it is looked up in a context
     with the TAG specified.

     The style name consists of field names separated by hyphens, for
     example ‘users-hosts-ports’.  For each field for a value is already
     known, a SPEC of the form FIELD‘=’PATTERN is given.  For example,
     if the command line so far specifies a user ‘pws’, the argument
     ‘users=pws’ should appear.

     The next argument with no equals sign is taken as the name of the
     field for which completions should be generated (presumably not one
     of the FIELDs for which the value is known).

     The matches generated will be taken from the value of the style.
     These should contain the possible values for the combinations in
     the appropriate order (users, hosts, ports in the example above).
     The values for the different fields are separated by colons.  This
     can be altered with the option ‘-s’ to ‘_combination’ which
     specifies a pattern.  Typically this is a character class, as for
     example ‘-s "[:@]"’ in the case of the ‘users-hosts’ style.  Each
     FIELD‘=’PATTERN specification restricts the completions which apply
     to elements of the style with appropriately matching fields.

     If no style with the given name is defined for the given tag, or if
     none of the strings in style’s value match, but a function name of
     the required field preceded by an underscore is defined, that
     function will be called to generate the matches.  For example, if
     there is no ‘users-hosts-ports’ or no matching hostname when a host
     is required, the function ‘_hosts’ will automatically be called.

     If the same name is used for more than one field, in both the
     FIELD‘=’PATTERN and the argument that gives the name of the field
     to be completed, the number of the field (starting with one) may be
     given after the fieldname, separated from it by a colon.

     All arguments after the required field name are passed to ‘compadd’
     when generating matches from the style value, or to the functions
     for the fields if they are called.

‘_command_names’ [ ‘-e’ | ‘-’ ]

     This function completes words that are valid at command position:
     names of aliases, builtins, hashed commands, functions, and so on.
     If the ‘-e’ flag is given, or if the list of precommands contains a
     non-builtin command (e.g.  because ‘_normal -p’ has been used
     previously), only hashed commands are completed.  The ‘-’ flag is
     ignored.

‘_comp_locale’

     This function resets all the locale categories other than
     ‘LC_CTYPE’ to ‘C’ so that the output from external commands can be
     easily analyzed by the completion system.  ‘LC_CTYPE’ retains the
     current value (taking ‘LC_ALL’ and ‘LANG’ into account), ensuring
     that non-ASCII characters in file names are still handled properly.

     This function should normally be run only in a subshell, because
     the new locale is exported to the environment.  Typical usage would
     be ‘$(_comp_locale;’ COMMAND …‘‘)‘‘.

‘_completers’ [ ‘-p’ ]

     This function completes names of completers.

     ‘-p’

          Include the leading underscore (‘_’) in the matches.

‘_default’

     This function corresponds to the ‘-default-’ special context which
     is applied where no completion is defined.  It is useful to call it
     under certain error conditions such as completion after an
     unrecognised subcommand.  This applies the concept of graceful
     degradation to the completion system, allowing it to fallback on
     basic completion of commonly useful things like filenames.

‘_describe [-12JVx’] [ ‘-oO’ | ‘-t’ TAG ] DESCR NAME1 [ NAME2 ] [ OPT …
]

          [ ‘--’ NAME1 [ NAME2 ] [ OPT … ] … ]

     This function associates completions with descriptions.  Multiple
     groups separated by ‘--’ can be supplied, potentially with
     different completion options OPTs.

     The DESCR is taken as a string to display above the matches if the
     ‘format’ style for the ‘descriptions’ tag is set.

     This is followed by one or two names of arrays.  Alternatively, the
     arrays may be given inline, following the rules described below,
     using the syntax ‘(’ITEM …‘)’.  (There is no separate ‘((’…‘))’
     form as with ‘_arguments’.)

     The array NAME1 contains the possible completions with their
     (optional) descriptions in the form COMPLETION‘:’DESCRIPTION.  Any
     literal colons in COMPLETION must be quoted with a backslash.  If a
     NAME2 is given, it should have the same number of elements as
     NAME1; in this case the corresponding elements are added as
     possible completions instead of the COMPLETION strings from NAME1.
     The completion list will retain the descriptions from NAME1.

     Finally, a set of options to pass to ‘compadd’ can appear.

     If the option ‘-o’ appears before the first argument, the matches
     added will be treated as names of command options (N.B. not shell
     options), typically following a ‘-’, ‘--’ or ‘+’ on the command
     line.  In this case ‘_describe’ uses the ‘prefix-hidden’,
     ‘prefix-needed’ and ‘verbose’ styles to find out if the strings
     should be added as completions and if the descriptions should be
     shown.  Without the ‘-o’ option, only the ‘verbose’ style is used
     to decide how descriptions are shown.  If ‘-O’ is used instead of
     ‘-o’, command options are completed as above but ‘_describe’ will
     not handle the ‘prefix-needed’ style.

     With the ‘-t’ option a TAG can be specified.  The default is
     ‘values’ or, if the ‘-o’ option is given, ‘options’.

     The options ‘-1’, ‘-2’, ‘-J’, ‘-V’, ‘-x’ are passed to
     ‘_next_label’.

     If selected by the ‘list-grouped’ style, strings with the same
     description will appear together in the list.

     ‘_describe’ uses the ‘_all_labels’ function to generate the
     matches, so it does not need to appear inside a loop over tag
     labels.

‘_description’ [ ‘-x’ ] [ ‘-12VJ’ ] TAG NAME DESCR [ SPEC … ]

     This function is not to be confused with the previous one; it is
     used as a helper function for creating options to ‘compadd’.  It is
     buried inside many of the higher level completion functions and so
     often does not need to be called directly.

     The styles listed below are tested in the current context using the
     given TAG.  The resulting options for ‘compadd’ are put into the
     array named NAME (this is traditionally ‘expl’, but this convention
     is not enforced).  The description for the corresponding set of
     matches is passed to the function in DESCR.

     The styles tested are: ‘format’, ‘hidden’, ‘matcher’,
     ‘ignore-line’, ‘ignored-patterns’, ‘group-name’ and ‘sort’.  The
     ‘format’ style is first tested for the given TAG and then for the
     ‘descriptions’ tag if no value was found, while the remainder are
     only tested for the tag given as the first argument.  The function
     also calls ‘_setup’ which tests some more styles.

     The string returned by the ‘format’ style (if any) will be modified
     so that the sequence ‘%d’ is replaced by the DESCR given as the
     third argument without any leading or trailing white space.  If,
     after removing the white space, the DESCR is the empty string, the
     format style will not be used and the options put into the NAME
     array will not contain an explanation string to be displayed above
     the matches.

     If ‘_description’ is called with more than three arguments, the
     additional SPECs should be of the form CHAR‘:’STR.  These supply
     escape sequence replacements for the ‘format’ style: every
     appearance of ‘%’CHAR will be replaced by STRING.  If no additional
     SPECs are given but the description in DESCR conforms to a common
     form then further escape sequences are set for elements of that
     description.  These elements correspond to a default value (‘%o’),
     the units (‘%m’) range of acceptable values (‘%r’) and the
     remaining initial part of the description (‘%h’).  The form the
     description takes consists of specifying the units and range in
     parentheses and the default value in square brackets, for example:

           _description times expl 'timeout (seconds) (0-60) [20]'

     It is possible to use ‘zformat’ conditional expressions when
     styling these elements.  So, for example, to add ‘default:’ as a
     tag but only when there is a default value to show, the ‘format’
     style might include ‘%(o.default: %o.)’.

     If the ‘-x’ option is given, the description will be passed to
     ‘compadd’ using the ‘-x’ option instead of the default ‘-X’.  This
     means that the description will be displayed even if there are no
     corresponding matches.

     The options placed in the array NAME take account of the
     ‘group-name’ style, so matches are placed in a separate group where
     necessary.  The group normally has its elements sorted (by passing
     the option ‘-J’ to ‘compadd’), but if an option starting with ‘-V’,
     ‘-J’, ‘-1’, or ‘-2’ is passed to ‘_description’, that option will
     be included in the array.  Hence it is possible for the completion
     group to be unsorted by giving the option ‘-V’, ‘-1V’, or ‘-2V’.

     In most cases, the function will be used like this:

           local expl
           _description files expl file
           compadd "$expl[@]" - "$files[@]"

     Note the use of the parameter ‘expl’, the hyphen, and the list of
     matches.  Almost all calls to ‘compadd’ within the completion
     system use a similar format; this ensures that user-specified
     styles are correctly passed down to the builtins which implement
     the internals of completion.

‘_dir_list’ [ ‘-s’ SEP ] [ ‘-S’ ]

     Complete a list of directory names separated by colons (the same
     format as ‘$PATH’).

     ‘-s’ SEP

          Use SEP as separator between items.  SEP defaults to a colon
          (‘:’).

     ‘-S’

          Add SEP instead of slash (‘/’) as an autoremoveable suffix.

‘_dispatch’ CONTEXT STRING …

     This sets the current context to CONTEXT and looks for completion
     functions to handle this context by hunting through the list of
     command names or special contexts (as described above for
     ‘compdef’) given as STRINGs.  The first completion function to be
     defined for one of the contexts in the list is used to generate
     matches.  Typically, the last STRING is ‘-default-’ to cause the
     function for default completion to be used as a fallback.

     The function sets the parameter ‘$service’ to the STRING being
     tried, and sets the CONTEXT/COMMAND field (the fourth) of the
     ‘$curcontext’ parameter to the CONTEXT given as the first argument.

‘_email_addresses’ [ ‘-c’ ] [ ‘-n’ PLUGIN ]

     Complete email addresses.  Addresses are provided by plugins.

     ‘-c’

          Complete bare ‘localhost@domain.tld’ addresses, without a name
          part or a comment.  Without this option, RFC822 FIRSTNAME
          LASTNAME ‘<’ADDRESS‘>’ strings are completed.

     ‘-n’ PLUGIN

          Complete aliases from PLUGIN.

     The following plugins are available by default: ‘_email-ldap’ (see
     the ‘filter’ style), ‘_email-local’ (completes USER‘@’HOSTNAME Unix
     addresses), ‘_email-mail’ (completes aliases from ‘~/.mailrc’),
     ‘_email-mush’, ‘_email-mutt’, and ‘_email-pine’.

     Addresses from the ‘_email-’FOO plugin are added under the tag
     ‘email-’FOO.

     ‘Writing plugins’

     Plugins are written as separate functions with names starting with
     ‘_email-’.  They are invoked with the ‘-c’ option and ‘compadd’
     options.  They should either do their own completion or set the
     ‘$reply’ array to a list of ALIAS‘:’ADDRESS elements and return
     ‘300’.  New plugins will be picked up and run automatically.

‘_files’

     The function ‘_files’ is a wrapper around ‘_path_files’.  It
     supports all of the same functionality, with some enhancements –
     notably, it respects the ‘list-dirs-first’ style, and it allows
     users to override the behaviour of the ‘-g’ and ‘-/’ options with
     the ‘file-patterns’ style.  ‘_files’ should therefore be preferred
     over ‘_path_files’ in most cases.

     This function accepts the full set of options allowed by
     ‘_path_files’, described below.

‘_gnu_generic’

     This function is a simple wrapper around the ‘_arguments’ function
     described above.  It can be used to determine automatically the
     long options understood by commands that produce a list when passed
     the option ‘--help’.  It is intended to be used as a top-level
     completion function in its own right.  For example, to enable
     option completion for the commands ‘foo’ and ‘bar’, use

           compdef _gnu_generic foo bar

     after the call to ‘compinit’.

     The completion system as supplied is conservative in its use of
     this function, since it is important to be sure the command
     understands the option ‘--help’.

‘_guard’ [ OPTIONS ] PATTERN DESCR

     This function displays DESCR if PATTERN matches the string to be
     completed.  It is intended to be used in the ACTION for the
     specifications passed to ‘_arguments’ and similar functions.

     The return status is zero if the message was displayed and the word
     to complete is not empty, and non-zero otherwise.

     The PATTERN may be preceded by any of the options understood by
     ‘compadd’ that are passed down from ‘_description’, namely ‘-M’,
     ‘-J’, ‘-V’, ‘-1’, ‘-2’, ‘-n’, ‘-F’ and ‘-X’.  All of these options
     will be ignored.  This fits in conveniently with the
     argument-passing conventions of actions for ‘_arguments’.

     As an example, consider a command taking the options ‘-n’ and
     ‘-none’, where ‘-n’ must be followed by a numeric value in the same
     word.  By using:

           _arguments '-n-: :_guard "[0-9]#" "numeric value"' '-none'

     ‘_arguments’ can be made to both display the message ‘numeric value
     ``and complete options after’ -n<TAB>‘‘.  If the‘‘ -n‘‘ is already
     followed by one or more digits (the pattern passed to ‘_guard’)
     only the message will be displayed; if the ‘-n’ is followed by
     another character, only options are completed.

‘_message’ [ ‘-r12’ ] [ ‘-VJ’ GROUP ] DESCR

‘_message -e’ [ TAG ] DESCR

     The DESCR is used in the same way as the third argument to the
     ‘_description’ function, except that the resulting string will
     always be shown whether or not matches were generated.  This is
     useful for displaying a help message in places where no completions
     can be generated.

     The ‘format’ style is examined with the ‘messages’ tag to find a
     message; the usual tag, ‘descriptions’, is used only if the style
     is not set with the former.

     If the ‘-r’ option is given, no style is used; the DESCR is taken
     literally as the string to display.  This is most useful when the
     DESCR comes from a pre-processed argument list which already
     contains an expanded description.  Note that this option does not
     disable the ‘%’-sequence parsing done by ‘compadd’.

     The ‘-12VJ’ options and the GROUP are passed to ‘compadd’ and hence
     determine the group the message string is added to.

     The second ‘-e’ form gives a description for completions with the
     tag TAG to be shown even if there are no matches for that tag.
     This form is called by ‘_arguments’ in the event that there is no
     action for an option specification.  The tag can be omitted and if
     so the tag is taken from the parameter ‘$curtag’; this is
     maintained by the completion system and so is usually correct.
     Note that if there are no matches at the time this function is
     called, ‘compstate[insert]’ is cleared, so additional matches
     generated later are not inserted on the command line.

‘_multi_parts’ [ ‘-i’ ] SEP ARRAY

     The argument SEP is a separator character.  The ARRAY may be either
     the name of an array parameter or a literal array in the form ‘(foo
     bar)’, a parenthesised list of words separated by whitespace.  The
     possible completions are the strings from the array.  However, each
     chunk delimited by SEP will be completed separately.  For example,
     the ‘_tar’ function uses ‘_multi_parts’ ‘/’ PATHARRAY to complete
     partial file paths from the given array of complete file paths.

     The ‘-i’ option causes ‘_multi_parts’ to insert a unique match even
     if that requires multiple separators to be inserted.  This is not
     usually the expected behaviour with filenames, but certain other
     types of completion, for example those with a fixed set of
     possibilities, may be more suited to this form.

     Like other utility functions, this function accepts the ‘-V’, ‘-J’,
     ‘-1’, ‘-2’, ‘-n’, ‘-f’, ‘-X’, ‘-M’, ‘-P’, ‘-S’, ‘-r’, ‘-R’, and
     ‘-q’ options and passes them to the ‘compadd’ builtin.

‘_next_label’ [ ‘-x’ ] [ ‘-12VJ’ ] TAG NAME DESCR [ OPTION … ]

     This function is used to implement the loop over different tag
     labels for a particular tag as described above for the ‘tag-order’
     style.  On each call it checks to see if there are any more tag
     labels; if there is it returns status zero, otherwise non-zero.  As
     this function requires a current tag to be set, it must always
     follow a call to ‘_tags’ or ‘_requested’.

     The ‘-x12VJ’ options and the first three arguments are passed to
     the ‘_description’ function.  Where appropriate the TAG will be
     replaced by a tag label in this call.  Any description given in the
     ‘tag-order’ style is preferred to the DESCR passed to
     ‘_next_label’.

     The OPTIONs given after the DESCR are set in the parameter given by
     NAME, and hence are to be passed to ‘compadd’ or whatever function
     is called to add the matches.

     Here is a typical use of this function for the tag ‘foo’.  The call
     to ‘_requested’ determines if tag ‘foo’ is required at all; the
     loop over ‘_next_label’ handles any labels defined for the tag in
     the ‘tag-order’ style.

           local expl ret=1
           ...
           if _requested foo; then
             ...
             while _next_label foo expl '...'; do
               compadd "$expl[@]" ... && ret=0
             done
             ...
           fi
           return ret

‘_normal’ [ ‘-P’ | ‘-p’ PRECOMMAND ]

     This is the standard function called to handle completion outside
     any special ‘-’CONTEXT‘-’.  It is called both to complete the
     command word and also the arguments for a command.  In the second
     case, ‘_normal’ looks for a special completion for that command,
     and if there is none it uses the completion for the ‘-default-’
     context.

     A second use is to reexamine the command line specified by the
     ‘$words’ array and the ‘$CURRENT’ parameter after those have been
     modified.  For example, the function ‘_precommand’, which completes
     after precommand specifiers such as ‘nohup’, removes the first word
     from the ‘words’ array, decrements the ‘CURRENT’ parameter, then
     calls ‘_normal -p $service’.  The effect is that ‘nohup’ CMD … is
     treated in the same way as CMD ….

     ‘-P’

          Reset the list of precommands.  This option should be used if
          completing a command line which allows internal commands (e.g.
          builtins and functions) regardless of prior precommands (e.g.
          ‘zsh -c’).

     ‘-p’ PRECOMMAND

          Append PRECOMMAND to the list of precommands.  This option
          should be used in nearly all cases in which ‘-P’ is not
          applicable.  An advantage of using this option is that it can
          automatically signal to ‘_command_names’ that subsequent
          completion should be limited to hashed commands, which is
          usually the desired behaviour following commands like ‘chroot’
          and ‘nohup’.

     If the command name matches one of the patterns given by one of the
     options ‘-p’ or ‘-P’ to ‘compdef’, the corresponding completion
     function is called and then the parameter ‘_compskip’ is checked.
     If it is set completion is terminated at that point even if no
     matches have been found.  This is the same effect as in the
     ‘-first-’ context.

‘_numbers’ [ OPTION … ] [ DESCRIPTION ] [ SUFFIX … ]

     This can be used where a number is followed by a suffix to indicate
     the units.  The unit suffixes are completed and can also be
     included in the description used when completion is invoked for the
     preceding number.

     In addition to common ‘compadd’ options, ‘_numbers’ accepts the
     following options:

     ‘-t’ TAG

          Specify a tag to use instead of the default of ‘numbers’.

     ‘-u’ UNITS

          Indicate the default units for the number, e.g.  ‘bytes’.

     ‘-l’ MIN

          Specify the lowest possible value for the number.

     ‘-m’ MAX

          Specify the highest possible value for the number.

     ‘-d’ DEFAULT

          Specify the default value.

     ‘-N’

          Allow negative numbers.  This is implied if the range includes
          a negative.

     ‘-f’

          Allow decimal numbers.

     Where a particular suffix represents the default units for a
     number, it should be prefixed with a colon.  Additionally, suffixes
     can be followed by a colon and a description.  So for example, the
     following allows the age of something to be specified, either in
     seconds or with an optional suffix with a longer unit of time:

           _numbers -u seconds age :s:seconds m:minutes h:hours d:days

     It is typically helpful for units to be presented in order of
     magnitude when completed.  To facilitate this, the order in which
     they are given is preserved.

     When the ‘format’ style is looked up with the ‘descriptions’ tag or
     the tag specified with ‘-t’, the list of suffixes is available as a
     ‘%x’ escape sequence.  This is in addition to the usual sequences
     documented under the ‘format’ style.  The form this list takes can
     also be configured.  To this end, the ‘format’ style is first
     looked up with the tag ‘unit-suffixes’.  The retrieved format is
     applied to each suffix in turn and the results are then
     concatenated to form the completed list.  For the ‘unit-suffixes’
     format, ‘%x’ expands to the individual suffix and ‘%X’ to its
     description.  ‘%d’’ indicates a default suffix and can be used in a
     condition.  The index and reverse index are set in ‘%i’ and ‘%r’
     respectively and are useful for text included only with the first
     and last suffixes in the list.  So for example, the following joins
     the suffixes together as a comma-separated list:

           zstyle ':completion:*:unit-suffixes' format '%x%(r::,)'

‘_options’

     This can be used to complete the names of shell options.  It
     provides a matcher specification that ignores a leading ‘no’,
     ignores underscores and allows upper-case letters to match their
     lower-case counterparts (for example, ‘glob’, ‘noglob’, ‘NO_GLOB’
     are all completed).  Any arguments are propagated to the ‘compadd’
     builtin.

‘_options_set’ and ‘_options_unset’

     These functions complete only set or unset options, with the same
     matching specification used in the ‘_options’ function.

     Note that you need to uncomment a few lines in the ‘_main_complete’
     function for these functions to work properly.  The lines in
     question are used to store the option settings in effect before the
     completion widget locally sets the options it needs.  Hence these
     functions are not generally used by the completion system.

‘_parameters’

     This is used to complete the names of shell parameters.

     The option ‘-g’ PATTERN limits the completion to parameters whose
     type matches the PATTERN.  The type of a parameter is that shown by
     ‘print ${(t)’PARAM‘}’, hence judicious use of ‘*’ in PATTERN is
     probably necessary.

     All other arguments are passed to the ‘compadd’ builtin.

‘_path_files’

     This function is used throughout the completion system to complete
     filenames.  It allows completion of partial paths.  For example,
     the string ‘/u/i/s/sig’ may be completed to
     ‘/usr/include/sys/signal.h’.

     The options accepted by both ‘_path_files’ and ‘_files’ are:

     ‘-f’

          Complete all filenames.  This is the default.

     ‘-/’

          Specifies that only directories should be completed.

     ‘-g’ PATTERN

          Specifies that only files matching the PATTERN should be
          completed.

     ‘-W’ PATHS

          Specifies path prefixes that are to be prepended to the string
          from the command line to generate the filenames but that
          should not be inserted as completions nor shown in completion
          listings.  Here, PATHS may be the name of an array parameter,
          a literal list of paths enclosed in parentheses or an absolute
          pathname.

     ‘-F’ IGNORED-FILES

          This behaves as for the corresponding option to the ‘compadd’
          builtin.  It gives direct control over which filenames should
          be ignored.  If the option is not present, the
          ‘ignored-patterns’ style is used.

     Both ‘_path_files’ and ‘_files’ also accept the following options
     which are passed to ‘compadd’: ‘-J’, ‘-V’, ‘-1’, ‘-2’, ‘-n’, ‘-X’,
     ‘-M’, ‘-P’, ‘-S’, ‘-q’, ‘-r’, and ‘-R’.

     Finally, the ‘_path_files’ function uses the styles ‘expand’,
     ‘ambiguous’, ‘special-dirs’, ‘list-suffixes’ and ‘file-sort’
     described above.

‘_phony’ … [ WORD … ] [ [ ‘--’ ] FUNCTION [ ‘-’ ] … ]

     This function allows extra matches to be mixed in with the matches
     generated by a function.  Sometimes a command accepts special
     values like ‘any’, ‘all’, or ‘none’ to be specified but the
     applicable completion function only generates real values.

     ‘_phony’ takes all the same arguments as ‘compadd’.  With the
     exception of ‘-a’, ‘-d’, ‘-k’ and ‘-l’, these are passed on to the
     following function.  Unless there is only one word, a ‘--’
     separator is needed to indicate where the words finish and the
     function begins.  You can also omit the function in which case an
     empty input won’t match the phony values, allowing descriptions to
     be displayed.  This is useful where real values can’t be generated
     and ‘_message -e’ would otherwise be used.

     To ensure that real and phony matches are grouped together, any
     options defining the match group should be passed to ‘_phony’.

‘_pick_variant’ [ ‘-b’ BUILTIN-LABEL ] [ ‘-c’ COMMAND ] [ ‘-r’ NAME ]

          LABEL‘=’PATTERN … LABEL [ ARG … ]

     This function is used to resolve situations where a single command
     name requires more than one type of handling, either because it has
     more than one variant or because there is a name clash between two
     different commands.

     The command to run is taken from the first element of the array
     ‘words’ unless this is overridden by the option ‘-c’.  This command
     is run and its output is compared with a series of patterns.
     Arguments to be passed to the command can be specified at the end
     after all the other arguments.  The patterns to try in order are
     given by the arguments LABEL‘=’PATTERN; if the output of COMMAND
     ARG … contains PATTERN, then LABEL is selected as the label for the
     command variant.  If none of the patterns match, the final command
     label is selected and status 1 is returned.

     If the ‘-b’ BUILTIN-LABEL is given, the command is tested to see if
     it is provided as a shell builtin, possibly autoloaded; if so, the
     label BUILTIN-LABEL is selected as the label for the variant.

     If the ‘-r’ NAME is given, the LABEL picked is stored in the
     parameter named NAME.

     The results are also cached in the ‘_cmd_variant’ associative array
     indexed by the name of the command run.

‘_regex_arguments’ NAME SPEC …

     This function generates a completion function NAME which matches
     the specifications SPECs, a set of regular expressions as described
     below.  After running ‘_regex_arguments’, the function NAME should
     be called as a normal completion function.  The pattern to be
     matched is given by the contents of the ‘words’ array up to the
     current cursor position joined together with null characters; no
     quotation is applied.

     The arguments are grouped as sets of alternatives separated by ‘|’,
     which are tried one after the other until one matches.  Each
     alternative consists of a one or more specifications which are
     tried left to right, with each pattern matched being stripped in
     turn from the command line being tested, until all of the group
     succeeds or until one fails; in the latter case, the next
     alternative is tried.  This structure can be repeated to arbitrary
     depth by using parentheses; matching proceeds from inside to
     outside.

     A special procedure is applied if no test succeeds but the
     remaining command line string contains no null character (implying
     the remaining word is the one for which completions are to be
     generated).  The completion target is restricted to the remaining
     word and any ACTIONs for the corresponding patterns are executed.
     In this case, nothing is stripped from the command line string.
     The order of evaluation of the ACTIONs can be determined by the
     ‘tag-order’ style; the various formats supported by ‘_alternative’
     can be used in ACTION.  The DESCR is used for setting up the array
     parameter ‘expl’.

     Specification arguments take one of following forms, in which
     metacharacters such as ‘(’, ‘)’, ‘#’ and ‘|’ should be quoted.

     ‘/’PATTERN‘/’ [‘%’LOOKAHEAD‘%’] [‘-’GUARD]
     [‘:’TAG‘:’DESCR‘:’ACTION]

          This is a single primitive component.  The function tests
          whether the combined pattern ‘(#b)((#B)’PATTERN‘)’LOOKAHEAD‘*’
          matches the command line string.  If so, GUARD is evaluated
          and its return status is examined to determine if the test has
          succeeded.  The PATTERN string ‘[]’ is guaranteed never to
          match.  The LOOKAHEAD is not stripped from the command line
          before the next pattern is examined.

          The argument starting with ‘:’ is used in the same manner as
          an argument to ‘_alternative’.

          A component is used as follows: PATTERN is tested to see if
          the component already exists on the command line.  If it does,
          any following specifications are examined to find something to
          complete.  If a component is reached but no such pattern
          exists yet on the command line, the string containing the
          ACTION is used to generate matches to insert at that point.

     ‘/’PATTERN‘/+’ [‘%’LOOKAHEAD‘%’] [‘-’GUARD]
     [‘:’TAG‘:’DESCR‘:’ACTION]

          This is similar to ‘/’PATTERN‘/’ … but the left part of the
          command line string (i.e.  the part already matched by
          previous patterns) is also considered part of the completion
          target.

     ‘/’PATTERN‘/-’ [‘%’LOOKAHEAD‘%’] [‘-’GUARD]
     [‘:’TAG‘:’DESCR‘:’ACTION]

          This is similar to ‘/’PATTERN‘/’ … but the ACTIONs of the
          current and previously matched patterns are ignored even if
          the following PATTERN matches the empty string.

     ‘(’ SPEC ‘)’

          Parentheses may be used to groups SPECs; note each parenthesis
          is a single argument to ‘_regex_arguments’.

     SPEC ‘#’

          This allows any number of repetitions of SPEC.

     SPEC SPEC

          The two SPECs are to be matched one after the other as
          described above.

     SPEC ‘|’ SPEC

          Either of the two SPECs can be matched.

     The function ‘_regex_words’ can be used as a helper function to
     generate matches for a set of alternative words possibly with their
     own arguments as a command line argument.

     Examples:

           _regex_arguments _tst /$'[^\0]#\0'/ \
               /$'[^\0]#\0'/ :'compadd aaa'

     This generates a function ‘_tst’ that completes ‘aaa’ as its only
     argument.  The TAG and DESCRIPTION for the action have been omitted
     for brevity (this works but is not recommended in normal use).  The
     first component matches the command word, which is arbitrary; the
     second matches any argument.  As the argument is also arbitrary,
     any following component would not depend on ‘aaa’ being present.

           _regex_arguments _tst /$'[^\0]#\0'/ \
               /$'aaa\0'/ :'compadd aaa'

     This is a more typical use; it is similar, but any following
     patterns would only match if ‘aaa’ was present as the first
     argument.

           _regex_arguments _tst /$'[^\0]#\0'/ \( \
               /$'aaa\0'/ :'compadd aaa' \
               /$'bbb\0'/ :'compadd bbb' \) \#

     In this example, an indefinite number of command arguments may be
     completed.  Odd arguments are completed as ‘aaa’ and even arguments
     as ‘bbb’.  Completion fails unless the set of ‘aaa’ and ‘bbb’
     arguments before the current one is matched correctly.

           _regex_arguments _tst /$'[^\0]#\0'/ \
               \( /$'aaa\0'/ :'compadd aaa' \| \
               /$'bbb\0'/ :'compadd bbb' \) \#

     This is similar, but either ‘aaa’ or ‘bbb’ may be completed for any
     argument.  In this case ‘_regex_words’ could be used to generate a
     suitable expression for the arguments.

‘_regex_words’ TAG DESCRIPTION SPEC …

     This function can be used to generate arguments for the
     ‘_regex_arguments’ command which may be inserted at any point where
     a set of rules is expected.  The TAG and DESCRIPTION give a
     standard tag and description pertaining to the current context.
     Each SPEC contains two or three arguments separated by a colon:
     note that there is no leading colon in this case.

     Each SPEC gives one of a set of words that may be completed at this
     point, together with arguments.  It is thus roughly equivalent to
     the ‘_arguments’ function when used in normal (non-regex)
     completion.

     The part of the SPEC before the first colon is the word to be
     completed.  This may contain a ‘*’; the entire word, before and
     after the ‘*’ is completed, but only the text before the ‘*’ is
     required for the context to be matched, so that further arguments
     may be completed after the abbreviated form.

     The second part of SPEC is a description for the word being
     completed.

     The optional third part of the SPEC describes how words following
     the one being completed are themselves to be completed.  It will be
     evaluated in order to avoid problems with quoting.  This means that
     typically it contains a reference to an array containing previously
     generated regex arguments.

     The option ‘-t’ TERM specifies a terminator for the word instead of
     the usual space.  This is handled as an auto-removable suffix in
     the manner of the option ‘-s’ SEP to ‘_values’.

     The result of the processing by ‘_regex_words’ is placed in the
     array ‘reply’, which should be made local to the calling function.
     If the set of words and arguments may be matched repeatedly, a ‘#’
     should be appended to the generated array at that point.

     For example:

           local -a reply
           _regex_words mydb-commands 'mydb commands' \
             'add:add an entry to mydb:$mydb_add_cmds' \
             'show:show entries in mydb'
           _regex_arguments _mydb "$reply[@]"
           _mydb "$@"

     This shows a completion function for a command ‘mydb’ which takes
     two command arguments, ‘add’ and ‘show’.  ‘show’ takes no
     arguments, while the arguments for ‘add’ have already been prepared
     in an array ‘mydb_add_cmds’, quite possibly by a previous call to
     ‘_regex_words’.

‘_requested’ [ ‘-x’ ] [ ‘-12VJ’ ] TAG [ NAME DESCR [ COMMAND [ ARG … ] ]

     This function is called to decide whether a tag already registered
     by a call to ‘_tags’ (see below) has been requested by the user and
     hence completion should be performed for it.  It returns status
     zero if the tag is requested and non-zero otherwise.  The function
     is typically used as part of a loop over different tags as follows:

           _tags foo bar baz
           while _tags; do
             if _requested foo; then
               ... # perform completion for foo
             fi
             ... # test the tags bar and baz in the same way
             ... # exit loop if matches were generated
           done

     Note that the test for whether matches were generated is not
     performed until the end of the ‘_tags’ loop.  This is so that the
     user can set the ‘tag-order’ style to specify a set of tags to be
     completed at the same time.

     If NAME and DESCR are given, ‘_requested’ calls the ‘_description’
     function with these arguments together with the options passed to
     ‘_requested’.

     If COMMAND is given, the ‘_all_labels’ function will be called
     immediately with the same arguments.  In simple cases this makes it
     possible to perform the test for the tag and the matching in one
     go.  For example:

           local expl ret=1
           _tags foo bar baz
           while _tags; do
             _requested foo expl 'description' \
                 compadd foobar foobaz && ret=0
             ...
             (( ret )) || break
           done

     If the COMMAND is not ‘compadd’, it must nevertheless be prepared
     to handle the same options.

‘_retrieve_cache’ CACHE_IDENTIFIER

     This function retrieves completion information from the file given
     by CACHE_IDENTIFIER, stored in a directory specified by the
     ‘cache-path’ style which defaults to ‘~/.zcompcache’.  The return
     status is zero if retrieval was successful.  It will only attempt
     retrieval if the ‘use-cache’ style is set, so you can call this
     function without worrying about whether the user wanted to use the
     caching layer.

     See ‘_store_cache’ below for more details.

‘_sep_parts’

     This function is passed alternating arrays and separators as
     arguments.  The arrays specify completions for parts of strings to
     be separated by the separators.  The arrays may be the names of
     array parameters or a quoted list of words in parentheses.  For
     example, with the array ‘hosts=(ftp news)’ the call ‘_sep_parts
     (foo bar)' @ hosts’’ will complete the string ‘f’ to ‘foo’ and the
     string ‘b@n’ to ‘bar@news’.

     This function accepts the ‘compadd’ options ‘-V’, ‘-J’, ‘-1’, ‘-2’,
     ‘-n’, ‘-X’, ‘-M’, ‘-P’, ‘-S’, ‘-r’, ‘-R’, and ‘-q’ and passes them
     on to the ‘compadd’ builtin used to add the matches.

‘_sequence’ [ ‘-s’ SEP ] [ ‘-n’ MAX ] [ ‘-d’ ] FUNCTION [ ‘-’ ] …

     This function is a wrapper to other functions for completing items
     in a separated list.  The same function is used to complete each
     item in the list.  The separator is specified with the ‘-s’ option.
     If ‘-s’ is omitted it will use ‘,’.  Duplicate values are not
     matched unless ‘-d’ is specified.  If there is a fixed or maximum
     number of items in the list, this can be specified with the ‘-n’
     option.

     Common ‘compadd’ options are passed on to the function.  It is
     possible to use ‘compadd’ directly with ‘_sequence’, though
     ‘_values’ may be more appropriate in this situation.

‘_setup’ TAG [ GROUP ]

     This function sets up the special parameters used by the completion
     system appropriately for the TAG given as the first argument.  It
     uses the styles ‘list-colors’, ‘list-packed’, ‘list-rows-first’,
     ‘last-prompt’, ‘accept-exact’, ‘menu’ and ‘force-list’.

     The optional GROUP supplies the name of the group in which the
     matches will be placed.  If it is not given, the TAG is used as the
     group name.

     This function is called automatically from ‘_description’ and hence
     is not normally called explicitly.

‘_shadow’ [ ‘-s’ SUFFIX ] [ – ] COMMAND_NAME …

‘_unshadow’

     The ‘_shadow’ function creates a copy of each of the shell
     functions in the COMMAND_NAME arguments.  The original functions
     can then be replaced by new implementations.  A later call to
     ‘_unshadow’ removes the new implementations, if any, and restores
     the originals.

     Recommended usage is to pair ‘_shadow’ and ‘_unshadow’ calls by use
     of an ‘always’ block:

           {
             _shadow fname
             function fname {
               # Do your new thing
             }
             # Invoke callers of fname
           } always {
             _unshadow
           }

     The SUFFIX, if supplied, is prepended by an ‘@’ character and then
     appended to each COMMAND_NAME to create the copy.  Thus

           _shadow -s XX foo

     creates a function named ‘foo@XX’.  This provides a well-known name
     for the original implementation if the new implementation needs to
     call it as a wrapper.  If a nested call to ‘_shadow’ uses the same
     SUFFIX, ‘no new copy is made’.  The presumption thus is that
     suffixes and new implementations correspond one to one.

     If COMMAND_NAME is a builtin or external command, and there has
     been no preceding ‘_shadow’ replacement made, the function so
     created calls the shadowed name prefixed by the ‘builtin’ or
     ‘command’ keywords as appropriate.

           {
             _shadow -s wrap compadd
             compadd () {
               # compadd@wrap runs builtin compadd
               compadd@wrap -O tmparr "$@" }
           } always {
             _unshadow
           }

     When no SUFFIX argument is present, ‘_shadow’ creates a unique
     suffix to avoid name collisions.

     Arguments of ‘_unshadow’ are ignored.  Every listed COMMAND_NAME
     for the most recent call to ‘_shadow’ is removed.  This differs
     from an early implementation that required ‘_unshadow’ to receive
     the same SUFFIX and COMMAND_NAME list as ‘_shadow’.

‘_store_cache’ CACHE_IDENTIFIER PARAM …

     This function, together with ‘_retrieve_cache’ and
     ‘_cache_invalid’, implements a caching layer which can be used in
     any completion function.  Data obtained by costly operations are
     stored in parameters; this function then dumps the values of those
     parameters to a file.  The data can then be retrieved quickly from
     that file via ‘_retrieve_cache’, even in different instances of the
     shell.

     The CACHE_IDENTIFIER specifies the file which the data should be
     dumped to.  The file is stored in a directory specified by the
     ‘cache-path’ style which defaults to ‘~/.zcompcache’.  The
     remaining PARAMs arguments are the parameters to dump to the file.

     The return status is zero if storage was successful.  The function
     will only attempt storage if the ‘use-cache’ style is set, so you
     can call this function without worrying about whether the user
     wanted to use the caching layer.

     The completion function may avoid calling ‘_retrieve_cache’ when it
     already has the completion data available as parameters.  However,
     in that case it should call ‘_cache_invalid’ to check whether the
     data in the parameters and in the cache are still valid.

     See the _perl_modules completion function for a simple example of
     the usage of the caching layer.

‘_tags’ [ [ ‘-C’ NAME ] TAG … ]

     If called with arguments, these are taken to be the names of tags
     valid for completions in the current context.  These tags are
     stored internally and sorted by using the ‘tag-order’ style.

     Next, ‘_tags’ is called repeatedly without arguments from the same
     completion function.  This successively selects the first, second,
     etc.  set of tags requested by the user.  The return status is zero
     if at least one of the tags is requested and non-zero otherwise.
     To test if a particular tag is to be tried, the ‘_requested’
     function should be called (see above).

     If ‘-C’ NAME is given, NAME is temporarily stored in the ARGUMENT
     field (the fifth) of the context in the ‘curcontext’ parameter
     during the call to ‘_tags’; the field is restored on exit.  This
     allows ‘_tags’ to use a more specific context without having to
     change and reset the ‘curcontext’ parameter (which has the same
     effect).

‘_tilde_files’

     Like ‘_files’, but resolve leading tildes according to the rules of
     filename expansion, so the suggested completions don’t start with a
     ‘~’ even if the filename on the command-line does.

‘_values’ [ ‘-O’ NAME ] [ ‘-s’ SEP ] [ ‘-S’ SEP ] [ ‘-wC’ ] DESC SPEC …

     This is used to complete arbitrary keywords (values) and their
     arguments, or lists of such combinations.

     If the first argument is the option ‘-O’ NAME, it will be used in
     the same way as by the ‘_arguments’ function.  In other words, the
     elements of the NAME array will be passed to ‘compadd’ when
     executing an action.

     If the first argument (or the first argument after ‘-O’ NAME) is
     ‘-s’, the next argument is used as the character that separates
     multiple values.  This character is automatically added after each
     value in an auto-removable fashion (see below); all values
     completed by ‘_values -s’ appear in the same word on the command
     line, unlike completion using ‘_arguments’.  If this option is not
     present, only a single value will be completed per word.

     Normally, ‘_values’ will only use the current word to determine
     which values are already present on the command line and hence are
     not to be completed again.  If the ‘-w’ option is given, other
     arguments are examined as well.

     The first non-option argument, DESC, is used as a string to print
     as a description before listing the values.

     All other arguments describe the possible values and their
     arguments in the same format used for the description of options by
     the ‘_arguments’ function (see above).  The only differences are
     that no minus or plus sign is required at the beginning, values can
     have only one argument, and the forms of action beginning with an
     equal sign are not supported.

     The character separating a value from its argument can be set using
     the option ‘-S’ (like ‘-s’, followed by the character to use as the
     separator in the next argument).  By default the equals sign will
     be used as the separator between values and arguments.

     Example:

           _values -s , 'description' \
                   '*foo[bar]' \
                   '(two)*one[number]:first count:' \
                   'two[another number]::second count:(1 2 3)'

     This describes three possible values: ‘foo’, ‘one’, and ‘two’.  The
     first is described as ‘bar’, takes no argument and may appear more
     than once.  The second is described as ‘number’, may appear more
     than once, and takes one mandatory argument described as ‘first
     count’; no action is specified, so it will not be completed.  The
     ‘(two)’ at the beginning says that if the value ‘one’ is on the
     line, the value ‘two’ will no longer be considered a possible
     completion.  Finally, the last value (‘two’) is described as
     ‘another number’ and takes an optional argument described as
     ‘second count’ for which the completions (to appear after an ‘=’)
     are ‘1’, ‘2’, and ‘3’.  The ‘_values’ function will complete lists
     of these values separated by commas.

     Like ‘_arguments’, this function temporarily adds another context
     name component to the arguments element (the fifth) of the current
     context while executing the ACTION.  Here this name is just the
     name of the value for which the argument is completed.

     The style ‘verbose’ is used to decide if the descriptions for the
     values (but not those for the arguments) should be printed.

     The associative array ‘val_args’ is used to report values and their
     arguments; this works similarly to the ‘opt_args’ associative array
     used by ‘_arguments’.  Hence the function calling ‘_values’ should
     declare the local parameters ‘state’, ‘state_descr’, ‘line’,
     ‘context’ and ‘val_args’:

           local context state state_descr line
           typeset -A val_args

     when using an action of the form ‘->’STRING.  With this function
     the ‘context’ parameter will be set to the name of the value whose
     argument is to be completed.  Note that for ‘_values’, the ‘state’
     and ‘state_descr’ are scalars rather than arrays.  Only a single
     matching state is returned.

     Note also that ‘_values’ normally adds the character used as the
     separator between values as an auto-removable suffix (similar to a
     ‘/’ after a directory).  However, this is not possible for a
     ‘->’STRING action as the matches for the argument are generated by
     the calling function.  To get the usual behaviour, the calling
     function can add the separator X as a suffix by passing the options
     ‘-qS’ X either directly or indirectly to ‘compadd’.

     The option ‘-C’ is treated in the same way as it is by
     ‘_arguments’.  In that case the parameter ‘curcontext’ should be
     made local instead of ‘context’ (as described above).

‘_wanted’ [ ‘-x’ ] [ ‘-C’ NAME ] [ ‘-12VJ’ ] TAG NAME DESCR COMMAND [
ARG …]

     In many contexts, completion can only generate one particular set
     of matches, usually corresponding to a single tag.  However, it is
     still necessary to decide whether the user requires matches of this
     type.  This function is useful in such a case.

     The arguments to ‘_wanted’ are the same as those to ‘_requested’,
     i.e.  arguments to be passed to ‘_description’.  However, in this
     case the COMMAND is not optional; all the processing of tags,
     including the loop over both tags and tag labels and the generation
     of matches, is carried out automatically by ‘_wanted’.

     Hence to offer only one tag and immediately add the corresponding
     matches with the given description:

           local expl
           _wanted tag expl 'description'      compadd -- MATCH1 MATCH2...

     Note that, as for ‘_requested’, the COMMAND must be able to accept
     options to be passed down to ‘compadd’.

     Like ‘_tags’ this function supports the ‘-C’ option to give a
     different name for the argument context field.  The ‘-x’ option has
     the same meaning as for ‘_description’.

‘_widgets’ [ ‘-g’ PATTERN ]

     This function completes names of zle widgets (see *note Zle
     Widgets: d8.).  The PATTERN, if present, is matched against values
     of the ‘$widgets’ special parameter, documented in *note The
     zsh/zleparameter Module: fc.


File: zsh.info,  Node: Completion System Variables,  Next: Completion Directories,  Prev: Utility Functions,  Up: Completion System

19.7 Completion System Variables
================================

There are some standard variables, initialised by the ‘_main_complete’
function and then used from other functions.

The standard variables are:

‘_comp_caller_options’

     The completion system uses ‘setopt’ to set a number of options.
     This allows functions to be written without concern for
     compatibility with every possible combination of user options.
     However, sometimes completion needs to know what the user’s option
     preferences are.  These are saved in the ‘_comp_caller_options’
     associative array.  Option names, spelled in lowercase without
     underscores, are mapped to one or other of the strings ‘on’ and
     ‘off’.

‘_comp_priv_prefix’

     Completion functions such as ‘_sudo’ can set the
     ‘_comp_priv_prefix’ array to a command prefix that may then be used
     by ‘_call_program’ to match the privileges when calling programs to
     generate matches.

Two more features are offered by the ‘_main_complete’ function.  The
arrays ‘compprefuncs’ and ‘comppostfuncs’ may contain names of functions
that are to be called immediately before or after completion has been
tried.  A function will only be called once unless it explicitly
reinserts itself into the array.


File: zsh.info,  Node: Completion Directories,  Prev: Completion System Variables,  Up: Completion System

19.8 Completion Directories
===========================

In the source distribution, the files are contained in various
subdirectories of the ‘Completion’ directory.  They may have been
installed in the same structure, or into one single function directory.
The following is a description of the files found in the original
directory structure.  If you wish to alter an installed file, you will
need to copy it to some directory which appears earlier in your ‘fpath’
than the standard directory where it appears.

‘Base’

     The core functions and special completion widgets automatically
     bound to keys.  You will certainly need most of these, though will
     probably not need to alter them.  Many of these are documented
     above.

‘Zsh’

     Functions for completing arguments of shell builtin commands and
     utility functions for this.  Some of these are also used by
     functions from the ‘Unix’ directory.

‘Unix’

     Functions for completing arguments of external commands and suites
     of commands.  They may need modifying for your system, although in
     many cases some attempt is made to decide which version of a
     command is present.  For example, completion for the ‘mount’
     command tries to determine the system it is running on, while
     completion for many other utilities try to decide whether the GNU
     version of the command is in use, and hence whether the ‘--help’
     option is supported.

‘X’, ‘AIX’, ‘BSD’, …

     Completion and utility function for commands available only on some
     systems.  These are not arranged hierarchically, so, for example,
     both the ‘Linux’ and ‘Debian’ directories, as well as the ‘X’
     directory, may be useful on your system.


File: zsh.info,  Node: Completion Using compctl,  Next: Zsh Modules,  Prev: Completion System,  Up: Top

20 Completion Using compctl
***************************

* Menu:

* Types of completion::
* Command Flags::
* Option Flags::
* Alternative Completion::
* Extended Completion::
* Example::


File: zsh.info,  Node: Types of completion,  Next: Command Flags,  Up: Completion Using compctl

20.1 Types of completion
========================

This version of zsh has two ways of performing completion of words on
the command line.  New users of the shell may prefer to use the newer
and more powerful system based on shell functions; this is described in
Completion System, and the basic shell mechanisms which support it are
described in Completion Widgets.  This chapter describes the older
‘compctl’ command.  Description ——————————————————————————– ..  index::
single: compctl; Function

   * ‘compctl’ [ ‘-CDT’ ] OPTIONS [ COMMAND … ]

   * ‘compctl’ [ ‘-CDT’ ] OPTIONS [ ‘-x’ PATTERN OPTIONS ‘-’ … ‘--’ ]

   * [ ‘+’ OPTIONS [ ‘-x’ … ‘--’ ] … [‘+’] ] [ COMMAND … ]

   * ‘compctl’ ‘-M’ MATCH-SPECS …

   * ‘compctl’ ‘-L’ [ ‘-CDTM’ ] [ COMMAND … ]

   * ‘compctl’ ‘+’ COMMAND …

Control the editor’s completion behavior according to the supplied set
of OPTIONS.  Various editing commands, notably
‘expand-or-complete-word’, usually bound to tab, will attempt to
complete a word typed by the user, while others, notably
‘delete-char-or-list’, usually bound to ^D in EMACS editing mode, list
the possibilities; ‘compctl’ controls what those possibilities are.
They may for example be filenames (the most common case, and hence the
default), shell variables, or words from a user-specified list.


File: zsh.info,  Node: Command Flags,  Next: Option Flags,  Prev: Types of completion,  Up: Completion Using compctl

20.2 Command Flags
==================

Completion of the arguments of a command may be different for each
command or may use the default.  The behavior when completing the
command word itself may also be separately specified.  These correspond
to the following flags and arguments, all of which (except for ‘-L’) may
be combined with any combination of the OPTIONS described subsequently
in Option Flags:

COMMAND …

     controls completion for the named commands, which must be listed
     last on the command line.  If completion is attempted for a command
     with a pathname containing slashes and no completion definition is
     found, the search is retried with the last pathname component.  If
     the command starts with a ‘=’, completion is tried with the
     pathname of the command.

     Any of the COMMAND strings may be patterns of the form normally
     used for filename generation.  These should be quoted to protect
     them from immediate expansion; for example the command string
     ‘'foo*'’ arranges for completion of the words of any command
     beginning with ‘foo’.  When completion is attempted, all pattern
     completions are tried in the reverse order of their definition
     until one matches.  By default, completion then proceeds as normal,
     i.e.  the shell will try to generate more matches for the specific
     command on the command line; this can be overridden by including
     ‘-tn’ in the flags for the pattern completion.

     Note that aliases are expanded before the command name is
     determined unless the ‘COMPLETE_ALIASES’ option is set.  Commands
     may not be combined with the ‘-C’, ‘-D’ or ‘-T’ flags.

‘-C’

     controls completion when the command word itself is being
     completed.  If no ‘compctl -C’ command has been issued, the names
     of any executable command (whether in the path or specific to the
     shell, such as aliases or functions) are completed.

‘-D’

     controls default completion behavior for the arguments of commands
     not assigned any special behavior.  If no ‘compctl -D’ command has
     been issued, filenames are completed.

‘-T’

     supplies completion flags to be used before any other processing is
     done, even before processing for ‘compctl’s defined for specific
     commands.  This is especially useful when combined with extended
     completion (the ‘-x’ flag, see Extended Completion below).  Using
     this flag you can define default behavior which will apply to all
     commands without exception, or you can alter the standard behavior
     for all commands.  For example, if your access to the user database
     is too slow and/or it contains too many users (so that completion
     after ‘~’ is too slow to be usable), you can use

           compctl -T -x 's[~] C[0,[^/]#]' -k friends -S/ -tn

     to complete the strings in the array ‘friends’ after a ‘~’.  The
     ‘C[’…‘]’ argument is necessary so that this form of ‘~’-completion
     is not tried after the directory name is finished.

‘-L’

     lists the existing completion behavior in a manner suitable for
     putting into a start-up script; the existing behavior is not
     changed.  Any combination of the above forms, or the ‘-M’ flag
     (which must follow the ‘-L’ flag), may be specified, otherwise all
     defined completions are listed.  Any other flags supplied are
     ignored.

‘no argument’

     If no argument is given, ‘compctl’ lists all defined completions in
     an abbreviated form; with a list of OPTIONS, all completions with
     those flags set (not counting extended completion) are listed.

If the ‘+’ flag is alone and followed immediately by the COMMAND list,
the completion behavior for all the commands in the list is reset to the
default.  In other words, completion will subsequently use the options
specified by the ‘-D’ flag.

The form with ‘-M’ as the first and only option defines global matching
specifications (see *note Completion Matching Control: eb.).  The match
specifications given will be used for every completion attempt (only
when using ‘compctl’, not with the new completion system) and are tried
in the order in which they are defined until one generates at least one
match.  E.g.:

      compctl -M '' 'm:{a-zA-Z}={A-Za-z}'

This will first try completion without any global match specifications
(the empty string) and, if that generates no matches, will try case
insensitive completion.


File: zsh.info,  Node: Option Flags,  Next: Alternative Completion,  Prev: Command Flags,  Up: Completion Using compctl

20.3 Option Flags
=================

        * [ ‘-fcFBdeaRGovNAIOPZEnbjrzu/12’ ]

        * [ ‘-k’ ARRAY ] [ ‘-g’ GLOBSTRING ] [ ‘-s’ SUBSTSTRING ]

        * [ ‘-K’ FUNCTION ]

        * [ ‘-Q’ ] [ ‘-P’ PREFIX ] [ ‘-S’ SUFFIX ]

        * [ ‘-W’ FILE-PREFIX ] [ ‘-H’ NUM PATTERN ]

        * [ ‘-q’ ] [ ‘-X’ EXPLANATION ] [ ‘-Y’ EXPLANATION ]

        * [ ‘-y’ FUNC-OR-VAR ] [ ‘-l’ CMD ] [ ‘-h’ CMD ] [ ‘-U’ ]

        * [ ‘-t’ CONTINUE ] [ ‘-J’ NAME ] [ ‘-V’ NAME ]

        * [ ‘-M’ MATCH-SPEC ]

The remaining OPTIONS specify the type of command arguments to look for
during completion.  Any combination of these flags may be specified; the
result is a sorted list of all the possibilities.  The options are as
follows.

* Menu:

* Simple Flags::
* Flags with Arguments::
* Control Flags::


File: zsh.info,  Node: Simple Flags,  Next: Flags with Arguments,  Up: Option Flags

20.3.1 Simple Flags
-------------------

These produce completion lists made up by the shell itself:

‘-f’

     Filenames and file system paths.

‘-/’

     Just file system paths.

‘-c’

     Command names, including aliases, shell functions, builtins and
     reserved words.

‘-F’

     Function names.

‘-B’

     Names of builtin commands.

‘-m’

     Names of external commands.

‘-w’

     Reserved words.

‘-a’

     Alias names.

‘-R’

     Names of regular (non-global) aliases.

‘-G’

     Names of global aliases.

‘-d’

     This can be combined with ‘-F’, ‘-B’, ‘-w’, ‘-a’, ‘-R’ and ‘-G’ to
     get names of disabled functions, builtins, reserved words or
     aliases.

‘-e’

     This option (to show enabled commands) is in effect by default, but
     may be combined with ‘-d’; ‘-de’ in combination with ‘-F’, ‘-B’,
     ‘-w’, ‘-a’, ‘-R’ and ‘-G’ will complete names of functions,
     builtins, reserved words or aliases whether or not they are
     disabled.

‘-o’

     Names of shell options (see ‘zshoptions’).

‘-v’

     Names of any variable defined in the shell.

‘-N’

     Names of scalar (non-array) parameters.

‘-A’

     Array names.

‘-I’

     Names of integer variables.

‘-O’

     Names of read-only variables.

‘-p’

     Names of parameters used by the shell (including special
     parameters).

‘-Z’

     Names of shell special parameters.

‘-E’

     Names of environment variables.

‘-n’

     Named directories.

‘-b’

     Key binding names.

‘-j’

     Job names: the first word of the job leader’s command line.  This
     is useful with the ‘kill’ builtin.

‘-r’

     Names of running jobs.

‘-z’

     Names of suspended jobs.

‘-u’

     User names.


File: zsh.info,  Node: Flags with Arguments,  Next: Control Flags,  Prev: Simple Flags,  Up: Option Flags

20.3.2 Flags with Arguments
---------------------------

These have user supplied arguments to determine how the list of
completions is to be made up:

‘-k’ ARRAY

     Names taken from the elements of ‘$’ARRAY (note that the ‘$’ does
     not appear on the command line).  Alternatively, the argument ARRAY
     itself may be a set of space- or comma-separated values in
     parentheses, in which any delimiter may be escaped with a
     backslash; in this case the argument should be quoted.  For
     example,

           compctl -k "(cputime filesize datasize stacksize
                          coredumpsize resident descriptors)" limit

‘-g’ GLOBSTRING

     The GLOBSTRING is expanded using filename globbing; it should be
     quoted to protect it from immediate expansion.  The resulting
     filenames are taken as the possible completions.  Use ‘*(/)’
     instead of ‘*/’ for directories.  The ‘fignore’ special parameter
     is not applied to the resulting files.  More than one pattern may
     be given separated by blanks.  (Note that brace expansion is ‘not’
     part of globbing.  Use the syntax ‘(either|or)’ to match
     alternatives.)

‘-s’ SUBSTSTRING

     The SUBSTSTRING is split into words and these words are than
     expanded using all shell expansion mechanisms (see ‘zshexpn’).  The
     resulting words are taken as possible completions.  The ‘fignore’
     special parameter is not applied to the resulting files.  Note that
     ‘-g’ is faster for filenames.

‘-K’ FUNCTION

     Call the given function to get the completions.  Unless the name
     starts with an underscore, the function is passed two arguments:
     the prefix and the suffix of the word on which completion is to be
     attempted, in other words those characters before the cursor
     position, and those from the cursor position onwards.  The whole
     command line can be accessed with the ‘-c’ and ‘-l’ flags of the
     ‘read’ builtin.  The function should set the variable ‘reply’ to an
     array containing the completions (one completion per element); note
     that ‘reply’ should not be made local to the function.  From such a
     function the command line can be accessed with the ‘-c’ and ‘-l’
     flags to the ‘read’ builtin.  For example,

           function whoson { reply=(`users`); }
           compctl -K whoson talk

     completes only logged-on users after ‘talk’.  Note that ‘whoson’
     must return an array, so ‘`reply=`users\’‘’ would be incorrect.

‘-H’ NUM PATTERN

     The possible completions are taken from the last NUM history lines.
     Only words matching PATTERN are taken.  If NUM is zero or negative
     the whole history is searched and if PATTERN is the empty string
     all words are taken (as with ‘*’).  A typical use is

           compctl -D -f + -H 0 ''

     which forces completion to look back in the history list for a word
     if no filename matches.


File: zsh.info,  Node: Control Flags,  Prev: Flags with Arguments,  Up: Option Flags

20.3.3 Control Flags
--------------------

These do not directly specify types of name to be completed, but
manipulate the options that do:

‘-Q’

     This instructs the shell not to quote any metacharacters in the
     possible completions.  Normally the results of a completion are
     inserted into the command line with any metacharacters quoted so
     that they are interpreted as normal characters.  This is
     appropriate for filenames and ordinary strings.  However, for
     special effects, such as inserting a backquoted expression from a
     completion array (‘-k’) so that the expression will not be
     evaluated until the complete line is executed, this option must be
     used.

‘-P’ PREFIX

     The PREFIX is inserted just before the completed string; any
     initial part already typed will be completed and the whole PREFIX
     ignored for completion purposes.  For example,

           compctl -j -P "%" kill

     inserts a ‘%’ after the kill command and then completes job names.

‘-S’ SUFFIX

     When a completion is found the SUFFIX is inserted after the
     completed string.  In the case of menu completion the suffix is
     inserted immediately, but it is still possible to cycle through the
     list of completions by repeatedly hitting the same key.

‘-W’ FILE-PREFIX

     With directory FILE-PREFIX: for command, file, directory and
     globbing completion (options ‘-c’, ‘-f’, ‘-/’, ‘-g’), the file
     prefix is implicitly added in front of the completion.  For
     example,

           compctl -/ -W ~/Mail maildirs

     completes any subdirectories to any depth beneath the directory
     ‘~/Mail’, although that prefix does not appear on the command line.
     The FILE-PREFIX may also be of the form accepted by the ‘-k’ flag,
     i.e.  the name of an array or a literal list in parenthesis.  In
     this case all the directories in the list will be searched for
     possible completions.

‘-q’

     If used with a suffix as specified by the ‘-S’ option, this causes
     the suffix to be removed if the next character typed is a blank or
     does not insert anything or if the suffix consists of only one
     character and the next character typed is the same character; this
     the same rule used for the ‘AUTO_REMOVE_SLASH’ option.  The option
     is most useful for list separators (comma, colon, etc.).

‘-l’ CMD

     This option restricts the range of command line words that are
     considered to be arguments.  If combined with one of the extended
     completion patterns ‘p[...]’, ‘r[...]’, or ‘R[...]’ (see Extended
     Completion below) the range is restricted to the range of arguments
     specified in the brackets.  Completion is then performed as if
     these had been given as arguments to the CMD supplied with the
     option.  If the CMD string is empty the first word in the range is
     instead taken as the command name, and command name completion
     performed on the first word in the range.  For example,

           compctl -x 'r[-exec,;]' -l '' -- find

     completes arguments between ‘-exec’ and the following ‘;’ (or the
     end of the command line if there is no such string) as if they were
     a separate command line.

‘-h’ CMD

     Normally zsh completes quoted strings as a whole.  With this
     option, completion can be done separately on different parts of
     such strings.  It works like the ‘-l’ option but makes the
     completion code work on the parts of the current word that are
     separated by spaces.  These parts are completed as if they were
     arguments to the given CMD.  If CMD is the empty string, the first
     part is completed as a command name, as with ‘-l’.

‘-U’

     Use the whole list of possible completions, whether or not they
     actually match the word on the command line.  The word typed so far
     will be deleted.  This is most useful with a function (given by the
     ‘-K’ option) which can examine the word components passed to it (or
     via the ‘read’ builtin’s ‘-c’ and ‘-l’ flags) and use its own
     criteria to decide what matches.  If there is no completion, the
     original word is retained.  Since the produced possible completions
     seldom have interesting common prefixes and suffixes, menu
     completion is started immediately if ‘AUTO_MENU’ is set and this
     flag is used.

‘-y’ FUNC-OR-VAR

     The list provided by FUNC-OR-VAR is displayed instead of the list
     of completions whenever a listing is required; the actual
     completions to be inserted are not affected.  It can be provided in
     two ways.  Firstly, if FUNC-OR-VAR begins with a ‘$’ it defines a
     variable, or if it begins with a left parenthesis a literal array,
     which contains the list.  A variable may have been set by a call to
     a function using the ‘-K’ option.  Otherwise it contains the name
     of a function which will be executed to create the list.  The
     function will be passed as an argument list all matching
     completions, including prefixes and suffixes expanded in full, and
     should set the array ‘reply’ to the result.  In both cases, the
     display list will only be retrieved after a complete list of
     matches has been created.

     Note that the returned list does not have to correspond, even in
     length, to the original set of matches, and may be passed as a
     scalar instead of an array.  No special formatting of characters is
     performed on the output in this case; in particular, newlines are
     printed literally and if they appear output in columns is
     suppressed.

‘-X’ EXPLANATION

     Print EXPLANATION when trying completion on the current set of
     options.  A ‘%n’ in this string is replaced by the number of
     matches that were added for this explanation string.  The
     explanation only appears if completion was tried and there was no
     unique match, or when listing completions.  Explanation strings
     will be listed together with the matches of the group specified
     together with the ‘-X’ option (using the ‘-J’ or ‘-V’ option).  If
     the same explanation string is given to multiple ‘-X’ options, the
     string appears only once (for each group) and the number of matches
     shown for the ‘%n’ is the total number of all matches for each of
     these uses.  In any case, the explanation string will only be shown
     if there was at least one match added for the explanation string.

     The sequences ‘%B’, ‘%b’, ‘%S’, ‘%s’, ‘%U’, and ‘%u’ specify output
     attributes (bold, standout, and underline), ‘%F’, ‘%f’, ‘%K’, ‘%k’
     specify foreground and background colours, and ‘%{’…‘%}’ can be
     used to include literal escape sequences as in prompts.

‘-Y’ EXPLANATION

     Identical to ‘-X’, except that the EXPLANATION first undergoes
     expansion following the usual rules for strings in double quotes.
     The expansion will be carried out after any functions are called
     for the ‘-K’ or ‘-y’ options, allowing them to set variables.

‘-t’ CONTINUE

     The CONTINUE-string contains a character that specifies which set
     of completion flags should be used next.  It is useful:

     (i) With ‘-T’, or when trying a list of pattern completions, when
     ‘compctl’ would usually continue with ordinary processing after
     finding matches; this can be suppressed with ‘-tn’.

     (ii) With a list of alternatives separated by ‘+’, when ‘compctl’
     would normally stop when one of the alternatives generates matches.
     It can be forced to consider the next set of completions by adding
     ‘-t+’ to the flags of the alternative before the ‘+’.

     (iii) In an extended completion list (see below), when ‘compctl’
     would normally continue until a set of conditions succeeded, then
     use only the immediately following flags.  With ‘-t-’, ‘compctl’
     will continue trying extended completions after the next ‘-’; with
     ‘-tx’ it will attempt completion with the default flags, in other
     words those before the ‘-x’.

‘-J’ NAME

     This gives the name of the group the matches should be placed in.
     Groups are listed and sorted separately; likewise, menu completion
     will offer the matches in the groups in the order in which the
     groups were defined.  If no group name is explicitly given, the
     matches are stored in a group named ‘default’.  The first time a
     group name is encountered, a group with that name is created.
     After that all matches with the same group name are stored in that
     group.

     This can be useful with non-exclusive alternative completions.  For
     example, in

           compctl -f -J files -t+ + -v -J variables foo

     both files and variables are possible completions, as the ‘-t+’
     forces both sets of alternatives before and after the ‘+’ to be
     considered at once.  Because of the ‘-J’ options, however, all
     files are listed before all variables.

‘-V’ NAME

     Like ‘-J’, but matches within the group will not be sorted in
     listings nor in menu completion.  These unsorted groups are in a
     different name space from the sorted ones, so groups defined as ‘-J
     files’ and ‘-V files’ are distinct.

‘-1’

     If given together with the ‘-V’ option, makes only consecutive
     duplicates in the group be removed.  Note that groups with and
     without this flag are in different name spaces.

‘-2’

     If given together with the ‘-J’ or ‘-V’ option, makes all
     duplicates be kept.  Again, groups with and without this flag are
     in different name spaces.

‘-M’ MATCH-SPEC

     This defines additional matching control specifications that should
     be used only when testing words for the list of flags this flag
     appears in.  The format of the MATCH-SPEC string is described in
     *note Completion Matching Control: eb.


File: zsh.info,  Node: Alternative Completion,  Next: Extended Completion,  Prev: Option Flags,  Up: Completion Using compctl

20.4 Alternative Completion
===========================

        * ‘compctl’ [ ‘-CDT’ ] OPTIONS ‘+’ OPTIONS [ ‘+’ … ] [ ‘+’ ]
          COMMAND …

The form with ‘+’ specifies alternative options.  Completion is tried
with the options before the first ‘+’.  If this produces no matches
completion is tried with the flags after the ‘+’ and so on.  If there
are no flags after the last ‘+’ and a match has not been found up to
that point, default completion is tried.  If the list of flags contains
a ‘-t’ with a ‘+’ character, the next list of flags is used even if the
current list produced matches.

Additional options are available that restrict completion to some part
of the command line; this is referred to as ‘extended completion’.


File: zsh.info,  Node: Extended Completion,  Next: Example,  Prev: Alternative Completion,  Up: Completion Using compctl

20.5 Extended Completion
========================

        * ‘compctl’ [ ‘-CDT’ ] OPTIONS ‘-x’ PATTERN OPTIONS ‘-’ … ‘--’

        * [ COMMAND … ]

        * ‘compctl’ [ ‘-CDT’ ] OPTIONS [ ‘-x’ PATTERN OPTIONS ‘-’ … ‘--’
          ]

        * [ ‘+’ OPTIONS [ ‘-x’ … ‘--’ ] … [‘+’] ] [ COMMAND … ]

The form with ‘-x’ specifies extended completion for the commands given;
as shown, it may be combined with alternative completion using ‘+’.
Each PATTERN is examined in turn; when a match is found, the
corresponding OPTIONS, as described in Option Flags above, are used to
generate possible completions.  If no PATTERN matches, the OPTIONS given
before the ‘-x’ are used.

Note that each pattern should be supplied as a single argument and
should be quoted to prevent expansion of metacharacters by the shell.

A PATTERN is built of sub-patterns separated by commas; it matches if at
least one of these sub-patterns matches (they are ‘or’ed).  These
sub-patterns are in turn composed of other sub-patterns separated by
white spaces which match if all of the sub-patterns match (they are
‘and’ed).  An element of the sub-patterns is of the form C‘[...][...]’,
where the pairs of brackets may be repeated as often as necessary, and
matches if any of the sets of brackets match (an ‘or’).  The example
below makes this clearer.

The elements may be any of the following:

‘s[’STRING‘]’…

     Matches if the current word on the command line starts with one of
     the strings given in brackets.  The STRING is not removed and is
     not part of the completion.

‘S[’STRING‘]’…

     Like ‘s[’STRING‘]’ except that the STRING is part of the
     completion.

‘p[’FROM‘,’TO‘]’…

     Matches if the number of the current word is between one of the
     FROM and TO pairs inclusive.  The comma and TO are optional; TO
     defaults to the same value as FROM.  The numbers may be negative:
     ‘-’N refers to the N’th last word on the line.

‘c[’OFFSET‘,’STRING‘]’…

     Matches if the STRING matches the word offset by OFFSET from the
     current word position.  Usually OFFSET will be negative.

‘C[’OFFSET‘,’PATTERN‘]’…

     Like ‘c’ but using pattern matching instead.

‘w[’INDEX‘,’STRING‘]’…

     Matches if the word in position INDEX is equal to the corresponding
     STRING.  Note that the word count is made after any alias
     expansion.

‘W[’INDEX‘,’PATTERN‘]’…

     Like ‘w’ but using pattern matching instead.

‘n[’INDEX‘,’STRING‘]’…

     Matches if the current word contains STRING.  Anything up to and
     including the INDEXth occurrence of this string will not be
     considered part of the completion, but the rest will.  INDEX may be
     negative to count from the end: in most cases, INDEX will be 1 or
     -1.  For example,

           compctl -s '`users`' -x 'n[1,@]' -k hosts -- talk

     will usually complete usernames, but if you insert an ‘@’ after the
     name, names from the array HOSTS (assumed to contain hostnames,
     though you must make the array yourself) will be completed.  Other
     commands such as ‘rcp’ can be handled similarly.

‘N[’INDEX‘,’STRING‘]’…

     Like ‘n’ except that the string will be taken as a character class.
     Anything up to and including the INDEXth occurrence of any of the
     characters in STRING will not be considered part of the completion.

‘m[’MIN‘,’MAX‘]’…

     Matches if the total number of words lies between MIN and MAX
     inclusive.

‘r[’STR1‘,’STR2‘]’…

     Matches if the cursor is after a word with prefix STR1.  If there
     is also a word with prefix STR2 on the command line after the one
     matched by STR1 it matches only if the cursor is before this word.
     If the comma and STR2 are omitted, it matches if the cursor is
     after a word with prefix STR1.

‘R[’STR1‘,’STR2‘]’…

     Like ‘r’ but using pattern matching instead.

‘q[’STR‘]’…

     Matches the word currently being completed is in single quotes and
     the STR begins with the letter ‘s’, or if completion is done in
     double quotes and STR starts with the letter ‘d’, or if completion
     is done in backticks and STR starts with a ‘b’.


File: zsh.info,  Node: Example,  Prev: Extended Completion,  Up: Completion Using compctl

20.6 Example
============

      compctl -u -x 's[+] c[-1,-f],s[-f+]' \
        -g '~/Mail/*(:t)' - 's[-f],c[-1,-f]' -f -- mail

This is to be interpreted as follows:

If the current command is ‘mail’, then

     if ((the current word begins with ‘+’ and the previous word is
     ‘-f’) or (the current word begins with ‘-f+’)), then complete the
     non-directory part (the ‘:t’ glob modifier) of files in the
     directory ‘~/Mail’; else

     if the current word begins with ‘-f’ or the previous word was ‘-f’,
     then complete any file; else

     complete user names.


File: zsh.info,  Node: Zsh Modules,  Next: Calendar Function System,  Prev: Completion Using compctl,  Up: Top

21 Zsh Modules
**************

* Menu:

* Description: Description<6>.
* The zsh/attr Module::
* The zsh/cap Module::
* The zsh/clone Module::
* The zsh/compctl Module::
* The zsh/complete Module::
* The zsh/complist Module::
* The zsh/computil Module::
* The zsh/curses Module::
* The zsh/datetime Module::
* The zsh/db/gdbm Module::
* The zsh/deltochar Module::
* The zsh/example Module::
* The zsh/files Module::
* The zsh/hlgroup Module::
* The zsh/langinfo Module::
* The zsh/ksh93 Module::
* The zsh/mapfile Module::
* The zsh/mathfunc Module::
* The zsh/nearcolor Module::
* The zsh/newuser Module::
* The zsh/parameter Module::
* The zsh/pcre Module::
* The zsh/param/private Module::
* The zsh/regex Module::
* The zsh/random Module::
* The zsh/sched Module::
* The zsh/net/socket Module::
* The zsh/stat Module::
* The zsh/system Module::
* The zsh/net/tcp Module::
* The zsh/termcap Module::
* The zsh/terminfo Module::
* The zsh/watch Module::
* The zsh/zftp Module::
* The zsh/zle Module::
* The zsh/zleparameter Module::
* The zsh/zprof Module::
* The zsh/zpty Module::
* The zsh/zselect Module::
* The zsh/zutil Module::


File: zsh.info,  Node: Description<6>,  Next: The zsh/attr Module,  Up: Zsh Modules

21.1 Description
================

Some optional parts of zsh are in modules, separate from the core of the
shell.  Each of these modules may be linked in to the shell at build
time, or can be dynamically linked while the shell is running if the
installation supports this feature.  Modules are linked at runtime with
the ‘zmodload’ command, see *note Shell Builtin Commands: b6.

The modules that are bundled with the zsh distribution are:

*note The zsh/attr Module: 10d.

     Builtins for manipulating extended attributes (xattr).

*note The zsh/cap Module: bb.

     Builtins for manipulating POSIX.1e (POSIX.6) capability (privilege)
     sets.

*note The zsh/clone Module: bc.

     A builtin that can clone a running shell onto another terminal.

*note The zsh/compctl Module: be.

     The ‘compctl’ builtin for controlling completion.

*note The zsh/complete Module: 10e.

     The basic completion code.

*note The zsh/complist Module: f4.

     Completion listing extensions.

*note The zsh/computil Module: bd.

     A module with utility builtins needed for the shell function based
     completion system.

*note The zsh/curses Module: 10f.

     curses windowing commands

*note The zsh/datetime Module: 110.

     Some date/time commands and parameters.

*note The zsh/db/gdbm Module: 111.

     Builtins for managing associative array parameters tied to GDBM
     databases.

*note The zsh/deltochar Module: 112.

     A ZLE function duplicating EMACS’ ‘zap-to-char’.

*note The zsh/example Module: 113.

     An example of how to write a module.

*note The zsh/files Module: 114.

     Some basic file manipulation commands as builtins.

*note The zsh/hlgroup Module: 115.

     Alternative views of highlighting groups

*note The zsh/langinfo Module: 116.

     Interface to locale information.

*note The zsh/ksh93 Module: 117.

     Extended ksh93 compatibility for “emulate ksh”

*note The zsh/mapfile Module: 118.

     Access to external files via a special associative array.

*note The zsh/mathfunc Module: 119.

     Standard scientific functions for use in mathematical evaluations.

*note The zsh/nearcolor Module: 11a.

     Map colours to the nearest colour in the available palette.

*note The zsh/newuser Module: 11b.

     Arrange for files for new users to be installed.

*note The zsh/parameter Module: 33.

     Access to internal hash tables via special associative arrays.

*note The zsh/pcre Module: 11c.

     Interface to the PCRE library.

*note The zsh/param/private Module: 11d.

     Builtins for managing private-scoped parameters in function
     context.

*note The zsh/regex Module: 11e.

     Interface to the POSIX regex library.

*note The zsh/random Module: 94.

     Some high-quality randomness parameters and functions.

*note The zsh/sched Module: 96.

     A builtin that provides a timed execution facility within the
     shell.

*note The zsh/net/socket Module: ce.

     Manipulation of Unix domain sockets

*note The zsh/stat Module: c7.

     A builtin command interface to the ‘stat’ system call.

*note The zsh/system Module: 11f.

     A builtin interface to various low-level system features.

*note The zsh/net/tcp Module: cf.

     Manipulation of TCP sockets

*note The zsh/termcap Module: bf.

     Interface to the termcap database.

*note The zsh/terminfo Module: c0.

     Interface to the terminfo database.

*note The zsh/watch Module: 120.

     Reporting of login and logout events.

*note The zsh/zftp Module: cb.

     A builtin FTP client.

*note The zsh/zle Module: 99.

     The Zsh Line Editor, including the ‘bindkey’ and ‘vared’ builtins.

*note The zsh/zleparameter Module: fc.

     Access to internals of the Zsh Line Editor via parameters.

*note The zsh/zprof Module: cc.

     A module allowing profiling for shell functions.

*note The zsh/zpty Module: cd.

     A builtin for starting a command in a pseudo-terminal.

*note The zsh/zselect Module: 121.

     Block and return when file descriptors are ready.

*note The zsh/zutil Module: ca.

     Some utility builtins, e.g.  the one for supporting configuration
     via styles.


File: zsh.info,  Node: The zsh/attr Module,  Next: The zsh/cap Module,  Prev: Description<6>,  Up: Zsh Modules

21.2 The zsh/attr Module
========================

The ‘zsh/attr’ module is used for manipulating extended attributes.  The
‘-h’ option causes all commands to operate on symbolic links instead of
their targets.  The builtins in this module are:

‘zgetattr’ [ ‘-h’ ] FILENAME ATTRIBUTE [ PARAMETER ]

     Get the extended attribute ATTRIBUTE from the specified FILENAME.
     If the optional argument PARAMETER is given, the attribute is set
     on that parameter instead of being printed to stdout.

‘zsetattr’ [ ‘-h’ ] FILENAME ATTRIBUTE VALUE

     Set the extended attribute ATTRIBUTE on the specified FILENAME to
     VALUE.

‘zdelattr’ [ ‘-h’ ] FILENAME ATTRIBUTE

     Remove the extended attribute ATTRIBUTE from the specified
     FILENAME.

‘zlistattr’ [ ‘-h’ ] FILENAME [ PARAMETER ]

     List the extended attributes currently set on the specified
     FILENAME.  If the optional argument PARAMETER is given, the list of
     attributes is set on that parameter instead of being printed to
     stdout.

‘zgetattr’ and ‘zlistattr’ allocate memory dynamically.  If the
attribute or list of attributes grows between the allocation and the
call to get them, they return 2.  On all other errors, 1 is returned.
This allows the calling function to check for this case and retry.


File: zsh.info,  Node: The zsh/cap Module,  Next: The zsh/clone Module,  Prev: The zsh/attr Module,  Up: Zsh Modules

21.3 The zsh/cap Module
=======================

The ‘zsh/cap’ module is used for manipulating POSIX.1e (POSIX.6)
capability sets.  If the operating system does not support this
interface, the builtins defined by this module will do nothing.  The
builtins in this module are:

‘cap’ [ CAPABILITIES ]

     Change the shell’s process capability sets to the specified
     CAPABILITIES, otherwise display the shell’s current capabilities.

‘getcap’ FILENAME …

     This is a built-in implementation of the POSIX standard utility.
     It displays the capability sets on each specified FILENAME.

‘setcap’ CAPABILITIES FILENAME …

     This is a built-in implementation of the POSIX standard utility.
     It sets the capability sets on each specified FILENAME to the
     specified CAPABILITIES.


File: zsh.info,  Node: The zsh/clone Module,  Next: The zsh/compctl Module,  Prev: The zsh/cap Module,  Up: Zsh Modules

21.4 The zsh/clone Module
=========================

The ‘zsh/clone’ module makes available one builtin command:

‘clone’ TTY

     Creates a forked instance of the current shell, attached to the
     specified TTY.  In the new shell, the ‘PID’, ‘PPID’ and ‘TTY’
     special parameters are changed appropriately.  ‘$!’ is set to zero
     in the new shell, and to the new shell’s PID in the original shell.

     The return status of the builtin is zero in both shells if
     successful, and non-zero on error.

     The target of ‘clone’ should be an unused terminal, such as an
     unused virtual console or a virtual terminal created by

           xterm -e sh -c 'trap : INT QUIT TSTP; tty;
                   while :; do sleep 100000000; done'

     Some words of explanation are warranted about this long xterm
     command line: when doing clone on a pseudo-terminal, some other
     session (“session” meant as a unix session group, or SID) is
     already owning the terminal.  Hence the cloned zsh cannot acquire
     the pseudo-terminal as a controlling tty.  That means two things:

             * the job control signals will go to the
               sh-started-by-xterm process

          group (that’s why we disable INT QUIT and TSTP with trap;
          otherwise the while loop could get suspended or killed) * the
          cloned shell will have job control disabled, and the job
          control keys (control-C, control-and control-Z) will not work.

     This does not apply when cloning to an ‘unused’ vc.

     Cloning to a used (and unprepared) terminal will result in two
     processes reading simultaneously from the same terminal, with input
     bytes going randomly to either process.

     ‘clone’ is mostly useful as a shell built-in replacement for
     openvt.


File: zsh.info,  Node: The zsh/compctl Module,  Next: The zsh/complete Module,  Prev: The zsh/clone Module,  Up: Zsh Modules

21.5 The zsh/compctl Module
===========================

The ‘zsh/compctl’ module makes available two builtin commands.
‘compctl’, is the old, deprecated way to control completions for ZLE.
See ‘zshcompctl’.  The other builtin command, ‘compcall’ can be used in
user-defined completion widgets, see ‘zshcompwid’.


File: zsh.info,  Node: The zsh/complete Module,  Next: The zsh/complist Module,  Prev: The zsh/compctl Module,  Up: Zsh Modules

21.6 The zsh/complete Module
============================

The ‘zsh/complete’ module makes available several builtin commands which
can be used in user-defined completion widgets, see ‘zshcompwid’.


File: zsh.info,  Node: The zsh/complist Module,  Next: The zsh/computil Module,  Prev: The zsh/complete Module,  Up: Zsh Modules

21.7 The zsh/complist Module
============================

The ‘zsh/complist’ module offers three extensions to completion
listings: the ability to highlight matches in such a list, the ability
to scroll through long lists and a different style of menu completion.

* Menu:

* Colored Completion Listings::
* Scrolling in Completion Listings::
* Menu Selection::


File: zsh.info,  Node: Colored Completion Listings,  Next: Scrolling in Completion Listings,  Up: The zsh/complist Module

21.7.1 Colored Completion Listings
----------------------------------

Whenever one of the parameters ‘ZLS_COLORS’ or ‘ZLS_COLOURS’ is set and
the ‘zsh/complist’ module is loaded or linked into the shell, completion
lists will be colored.  Note, however, that ‘complist’ will not
automatically be loaded if it is not linked in: on systems with dynamic
loading, ‘zmodload zsh/complist’ is required.

The parameters ‘ZLS_COLORS’ and ‘ZLS_COLOURS’ describe how matches are
highlighted.  To turn on highlighting an empty value suffices, in which
case all the default values given below will be used.  The format of the
value of these parameters is the same as used by the GNU version of the
‘ls’ command: a colon-separated list of specifications of the form
NAME‘=’VALUE.  The NAME may be one of the following strings, most of
which specify file types for which the VALUE will be used.  The strings
and their default values are:

‘no 0’

     for normal text (i.e.  when displaying something other than a
     matched file)

‘fi 0’

     for regular files

‘di 32’

     for directories

‘ln 36’

     for symbolic links.  If this has the special value ‘target’,
     symbolic links are dereferenced and the target file used to
     determine the display format.

‘pi 31’

     for named pipes (FIFOs)

‘so 33’

     for sockets

‘bd 44;37’

     for block devices

‘cd 44;37’

     for character devices

‘or’ NONE

     for a symlink to nonexistent file (default is the value defined for
     ‘ln’)

‘mi’ NONE

     for a non-existent file (default is the value defined for ‘fi’);
     this code is currently not used

‘su 37;41’

     for files with setuid bit set

‘sg 30;43’

     for files with setgid bit set

‘tw 30;42’

     for world writable directories with sticky bit set

‘ow 34;43’

     for world writable directories without sticky bit set

‘sa’ NONE

     for files with an associated suffix alias; this is only tested
     after specific suffixes, as described below

‘st 37;44’

     for directories with sticky bit set but not world writable

‘ex 35’

     for executable files

‘lc \e[’

     for the left code (see below)

‘rc m’

     for the right code

‘tc 0’

     for the character indicating the file type printed after filenames
     if the ‘LIST_TYPES’ option is set

‘sp 0’

     for the spaces printed after matches to align the next column

‘ec’ NONE

     for the end code

Apart from these strings, the NAME may also be an asterisk (‘*’)
followed by any string.  The VALUE given for such a string will be used
for all files whose name ends with the string.  The NAME may also be an
equals sign (‘=’) followed by a pattern; the ‘EXTENDED_GLOB’ option will
be turned on for evaluation of the pattern.  The VALUE given for this
pattern will be used for all matches (not just filenames) whose display
string are matched by the pattern.  Definitions for the form with the
leading equal sign take precedence over the values defined for file
types, which in turn take precedence over the form with the leading
asterisk (file extensions).

The leading-equals form also allows different parts of the displayed
strings to be colored differently.  For this, the pattern has to use the
‘(#b)’ globbing flag and pairs of parentheses surrounding the parts of
the strings that are to be colored differently.  In this case the VALUE
may consist of more than one color code separated by equal signs.  The
first code will be used for all parts for which no explicit code is
specified and the following codes will be used for the parts matched by
the sub-patterns in parentheses.  For example, the specification
‘=(#b)(?)*(?)=0=3=7’ will be used for all matches which are at least two
characters long and will use the code ‘3’ for the first character, ‘7’
for the last character and ‘0’ for the rest.

All three forms of NAME may be preceded by a pattern in parentheses.  If
this is given, the VALUE will be used only for matches in groups whose
names are matched by the pattern given in the parentheses.  For example,
‘(g*)m*=43’ highlights all matches beginning with ‘m’ in groups whose
names begin with ‘g’ using the color code ‘43’.  In case of the ‘lc’,
‘rc’, and ‘ec’ codes, the group pattern is ignored.

Note also that all patterns are tried in the order in which they appear
in the parameter value until the first one matches which is then used.
Patterns may be matched against completions, descriptions (possibly with
spaces appended for padding), or lines consisting of a completion
followed by a description.  For consistent coloring it may be necessary
to use more than one pattern or a pattern with backreferences.

When printing a match, the code prints the value of ‘lc’, the value for
the file-type or the last matching specification with a ‘*’, the value
of ‘rc’, the string to display for the match itself, and then the value
of ‘ec’ if that is defined or the values of ‘lc’, ‘no’, and ‘rc’ if ‘ec’
is not defined.

The default values are ISO 6429 (ANSI) compliant and can be used on
vt100 compatible terminals such as ‘xterm’s.  On monochrome terminals
the default values will have no visible effect.  The ‘colors’ function
from the contribution can be used to get associative arrays containing
the codes for ANSI terminals (see *note Other Functions: 129.).  For
example, after loading ‘colors’, one could use ‘$color[red]’ to get the
code for foreground color red and ‘$color[bg-green]’ for the code for
background color green.

If the completion system invoked by compinit is used, these parameters
should not be set directly because the system controls them itself.
Instead, the ‘list-colors’ style should be used (see *note Completion
System Configuration: f1.).


File: zsh.info,  Node: Scrolling in Completion Listings,  Next: Menu Selection,  Prev: Colored Completion Listings,  Up: The zsh/complist Module

21.7.2 Scrolling in Completion Listings
---------------------------------------

To enable scrolling through a completion list, the ‘LISTPROMPT’
parameter must be set.  Its value will be used as the prompt; if it is
the empty string, a default prompt will be used.  The value may contain
escapes of the form ‘%x’.  It supports the escapes ‘%B’, ‘%b’, ‘%S’,
‘%s’, ‘%U’, ‘%u’, ‘%F’, ‘%f’, ‘%K’, ‘%k’ and ‘%{’…‘%}’ used also in
shell prompts as well as three pairs of additional sequences: a ‘%l’ or
‘%L’ is replaced by the number of the last line shown and the total
number of lines in the form NUMBER‘/’TOTAL; a ‘%m’ or ‘%M’ is replaced
with the number of the last match shown and the total number of matches;
and ‘%p’ or ‘%P’ is replaced with ‘Top’, ‘Bottom’ or the position of the
first line shown in percent of the total number of lines, respectively.
In each of these cases the form with the uppercase letter will be
replaced with a string of fixed width, padded to the right with spaces,
while the lowercase form will not be padded.

If the parameter ‘LISTPROMPT’ is set, the completion code will not ask
if the list should be shown.  Instead it immediately starts displaying
the list, stopping after the first screenful, showing the prompt at the
bottom, waiting for a keypress after temporarily switching to the
‘listscroll’ keymap.  Some of the zle functions have a special meaning
while scrolling lists:

‘send-break’

     stops listing discarding the key pressed

‘accept-line’, ‘down-history’, ‘down-line-or-history’

‘down-line-or-search’, ‘vi-down-line-or-history’

     scrolls forward one line

‘complete-word’, ‘menu-complete’, ‘expand-or-complete’

‘expand-or-complete-prefix’, ‘menu-complete-or-expand’

     scrolls forward one screenful

‘accept-search’

     stop listing but take no other action

Every other character stops listing and immediately processes the key as
usual.  Any key that is not bound in the ‘listscroll’ keymap or that is
bound to ‘undefined-key’ is looked up in the keymap currently selected.

As for the ‘ZLS_COLORS’ and ‘ZLS_COLOURS’ parameters, ‘LISTPROMPT’
should not be set directly when using the shell function based
completion system.  Instead, the ‘list-prompt’ style should be used.


File: zsh.info,  Node: Menu Selection,  Prev: Scrolling in Completion Listings,  Up: The zsh/complist Module

21.7.3 Menu Selection
---------------------

The ‘zsh/complist’ module also offers an alternative style of selecting
matches from a list, called menu selection, which can be used if the
shell is set up to return to the last prompt after showing a completion
list (see the ‘ALWAYS_LAST_PROMPT’ option in ‘zshoptions’).

Menu selection can be invoked directly by the widget ‘menu-select’
defined by this module.  This is a standard ZLE widget that can be bound
to a key in the usual way as described in ‘zshzle’.

Alternatively, the parameter ‘MENUSELECT’ can be set to an integer,
which gives the minimum number of matches that must be present before
menu selection is automatically turned on.  This second method requires
that menu completion be started, either directly from a widget such as
‘menu-complete’, or due to one of the options ‘MENU_COMPLETE’ or
‘AUTO_MENU’ being set.  If ‘MENUSELECT’ is set, but is 0, 1 or empty,
menu selection will always be started during an ambiguous menu
completion.

When using the completion system based on shell functions, the
‘MENUSELECT’ parameter should not be used (like the ‘ZLS_COLORS’ and
‘ZLS_COLOURS’ parameters described above).  Instead, the ‘menu’ style
should be used with the ‘select=’… keyword.

After menu selection is started, the matches will be listed.  If there
are more matches than fit on the screen, only the first screenful is
shown.  The matches to insert into the command line can be selected from
this list.  In the list one match is highlighted using the value for
‘ma’ from the ‘ZLS_COLORS’ or ‘ZLS_COLOURS’ parameter.  The default
value for this is ‘7’ which forces the selected match to be highlighted
using standout mode on a vt100-compatible terminal.  If neither
‘ZLS_COLORS’ nor ‘ZLS_COLOURS’ is set, the same terminal control
sequence as for the ‘%S’ escape in prompts is used.

If there are more matches than fit on the screen and the parameter
‘MENUPROMPT’ is set, its value will be shown below the matches.  It
supports the same escape sequences as ‘LISTPROMPT’, but the number of
the match or line shown will be that of the one where the mark is
placed.  If its value is the empty string, a default prompt will be
used.

The ‘MENUSCROLL’ parameter can be used to specify how the list is
scrolled.  If the parameter is unset, this is done line by line, if it
is set to ‘0’ (zero), the list will scroll half the number of lines of
the screen.  If the value is positive, it gives the number of lines to
scroll and if it is negative, the list will be scrolled the number of
lines of the screen minus the (absolute) value.

As for the ‘ZLS_COLORS’, ‘ZLS_COLOURS’ and ‘LISTPROMPT’ parameters,
neither ‘MENUPROMPT’ nor ‘MENUSCROLL’ should be set directly when using
the shell function based completion system.  Instead, the
‘select-prompt’ and ‘select-scroll’ styles should be used.

The completion code sometimes decides not to show all of the matches in
the list.  These hidden matches are either matches for which the
completion function which added them explicitly requested that they not
appear in the list (using the ‘-n’ option of the ‘compadd’ builtin
command) or they are matches which duplicate a string already in the
list (because they differ only in things like prefixes or suffixes that
are not displayed).  In the list used for menu selection, however, even
these matches are shown so that it is possible to select them.  To
highlight such matches the ‘hi’ and ‘du’ capabilities in the
‘ZLS_COLORS’ and ‘ZLS_COLOURS’ parameters are supported for hidden
matches of the first and second kind, respectively.

Selecting matches is done by moving the mark around using the zle
movement functions.  When not all matches can be shown on the screen at
the same time, the list will scroll up and down when crossing the top or
bottom line.  The following zle functions have special meaning during
menu selection.  Note that the following always perform the same task
within the menu selection map and cannot be replaced by user defined
widgets, nor can the set of functions be extended:

‘accept-line’, ‘accept-search’

     accept the current match and leave menu selection (but do not cause
     the command line to be accepted)

‘send-break’

     leaves menu selection and restores the previous contents of the
     command line

‘redisplay’, ‘clear-screen’

     execute their normal function without leaving menu selection

‘accept-and-hold’, ‘accept-and-menu-complete’

     accept the currently inserted match and continue selection allowing
     to select the next match to insert into the line

‘accept-and-infer-next-history’

     accepts the current match and then tries completion with menu
     selection again; in the case of files this allows one to select a
     directory and immediately attempt to complete files in it; if there
     are no matches, a message is shown and one can use ‘undo’ to go
     back to completion on the previous level, every other key leaves
     menu selection (including the other zle functions which are
     otherwise special during menu selection)

‘undo’

     removes matches inserted during the menu selection by one of the
     three functions before

‘down-history’, ‘down-line-or-history’

‘vi-down-line-or-history’, ‘down-line-or-search’

     moves the mark one line down

‘up-history’, ‘up-line-or-history’

‘vi-up-line-or-history’, ‘up-line-or-search’

     moves the mark one line up

‘forward-char’, ‘vi-forward-char’

     moves the mark one column right

‘backward-char’, ‘vi-backward-char’

     moves the mark one column left

‘forward-word’, ‘vi-forward-word’

‘vi-forward-word-end’, ‘emacs-forward-word’

     moves the mark one screenful down

‘backward-word’, ‘vi-backward-word’, ‘emacs-backward-word’

     moves the mark one screenful up

‘vi-forward-blank-word’, ‘vi-forward-blank-word-end’

     moves the mark to the first line of the next group of matches

‘vi-backward-blank-word’

     moves the mark to the last line of the previous group of matches

‘beginning-of-history’

     moves the mark to the first line

‘end-of-history’

     moves the mark to the last line

‘beginning-of-buffer-or-history’, ‘beginning-of-line’

‘beginning-of-line-hist’, ‘vi-beginning-of-line’

     moves the mark to the leftmost column

‘end-of-buffer-or-history’, ‘end-of-line’

‘end-of-line-hist’, ‘vi-end-of-line’

     moves the mark to the rightmost column

‘complete-word’, ‘menu-complete’, ‘expand-or-complete’

‘expand-or-complete-prefix’, ‘menu-expand-or-complete’

     moves the mark to the next match

‘reverse-menu-complete’

     moves the mark to the previous match

‘vi-insert’

     this toggles between normal and interactive mode; in interactive
     mode the keys bound to ‘self-insert’ and ‘self-insert-unmeta’
     insert into the command line as in normal editing mode but without
     leaving menu selection; after each character completion is tried
     again and the list changes to contain only the new matches; the
     completion widgets make the longest unambiguous string be inserted
     in the command line and ‘undo’ and ‘backward-delete-char’ go back
     to the previous set of matches

‘history-incremental-search-forward’

‘history-incremental-search-backward’

     this starts incremental searches in the list of completions
     displayed; in this mode, ‘accept-line’ only leaves incremental
     search, going back to the normal menu selection mode

All movement functions wrap around at the edges; any other zle function
not listed leaves menu selection and executes that function.  It is
possible to make widgets in the above list do the same by using the form
of the widget with a ‘.’ in front.  For example, the widget
‘.accept-line’ has the effect of leaving menu selection and accepting
the entire command line.

During this selection the widget uses the keymap ‘menuselect’.  Any key
that is not defined in this keymap or that is bound to ‘undefined-key’
is looked up in the keymap currently selected.  This is used to ensure
that the most important keys used during selection (namely the cursor
keys, return, and TAB) have sensible defaults.  However, keys in the
‘menuselect’ keymap can be modified directly using the ‘bindkey’ builtin
command (see *note Zle Builtins: ba.).  For example, to make the return
key leave menu selection without accepting the match currently selected
one could call

      bindkey -M menuselect '^M' send-break

after loading the ‘zsh/complist’ module.


File: zsh.info,  Node: The zsh/computil Module,  Next: The zsh/curses Module,  Prev: The zsh/complist Module,  Up: Zsh Modules

21.8 The zsh/computil Module
============================

The ‘zsh/computil’ module adds several builtin commands that are used by
some of the completion functions in the completion system based on shell
functions (see ‘zshcompsys’).  Except for ‘compquote’ these builtin
commands are very specialised and thus not very interesting when writing
your own completion functions.  In summary, these builtin commands are:

‘comparguments’

     This is used by the ‘_arguments’ function to do the argument and
     command line parsing.  Like ‘compdescribe’ it has an option ‘-i’ to
     do the parsing and initialize some internal state and various
     options to access the state information to decide what should be
     completed.

‘compdescribe’

     This is used by the ‘_describe’ function to build the displays for
     the matches and to get the strings to add as matches with their
     options.  On the first call one of the options ‘-i’ or ‘-I’ should
     be supplied as the first argument.  In the first case, display
     strings without the descriptions will be generated, in the second
     case, the string used to separate the matches from their
     descriptions must be given as the second argument and the
     descriptions (if any) will be shown.  All other arguments are like
     the definition arguments to ‘_describe’ itself.

     Once ‘compdescribe’ has been called with either the ‘-i’ or the
     ‘-I’ option, it can be repeatedly called with the ‘-g’ option and
     the names of four parameters as its arguments.  This will step
     through the different sets of matches and store the value of
     ‘compstate[list]’ in the first scalar, the options for ‘compadd’ in
     the second array, the matches in the third array, and the strings
     to be displayed in the completion listing in the fourth array.  The
     arrays may then be directly given to ‘compadd’ to register the
     matches with the completion code.

‘compfiles’

     Used by the ‘_path_files’ function to optimize complex recursive
     filename generation (globbing).  It does three things.  With the
     ‘-p’ and ‘-P’ options it builds the glob patterns to use, including
     the paths already handled and trying to optimize the patterns with
     respect to the prefix and suffix from the line and the match
     specification currently used.  The ‘-i’ option does the directory
     tests for the ‘ignore-parents’ style and the ‘-r’ option tests if a
     component for some of the matches are equal to the string on the
     line and removes all other matches if that is true.

‘compgroups’

     Used by the ‘_tags’ function to implement the internals of the
     ‘group-order’ style.  This only takes its arguments as names of
     completion groups and creates the groups for it (all six types:
     sorted and unsorted, both without removing duplicates, with
     removing all duplicates and with removing consecutive duplicates).

‘compquote’ [ ‘-p’ ] NAMES …

     There may be reasons to write completion functions that have to add
     the matches using the ‘-Q’ option to ‘compadd’ and perform quoting
     themselves.  Instead of interpreting the first character of the
     ‘all_quotes’ key of the ‘compstate’ special association and using
     the ‘q’ flag for parameter expansions, one can use this builtin
     command.  The arguments are the names of scalar or array parameters
     and the values of these parameters are quoted as needed for the
     innermost quoting level.  If the ‘-p’ option is given, quoting is
     done as if there is some prefix before the values of the
     parameters, so that a leading equal sign will not be quoted.

     The return status is non-zero in case of an error and zero
     otherwise.

‘comptags’

‘comptry’

     These implement the internals of the tags mechanism.

‘compvalues’

     Like ‘comparguments’, but for the ‘_values’ function.


File: zsh.info,  Node: The zsh/curses Module,  Next: The zsh/datetime Module,  Prev: The zsh/computil Module,  Up: Zsh Modules

21.9 The zsh/curses Module
==========================

The ‘zsh/curses’ module makes available one builtin command and various
parameters.

* Menu:

* Builtin::
* Parameters: Parameters<2>.


File: zsh.info,  Node: Builtin,  Next: Parameters<2>,  Up: The zsh/curses Module

21.9.1 Builtin
--------------

‘zcurses’ ‘init’

‘zcurses’ ‘end’

‘zcurses’ ‘addwin’ TARGETWIN NLINES NCOLS BEGIN_Y BEGIN_X [ PARENTWIN ]

‘zcurses’ ‘delwin’ TARGETWIN

‘zcurses’ ‘refresh’ [ TARGETWIN … ]

‘zcurses’ ‘touch’ TARGETWIN …

‘zcurses’ ‘move’ TARGETWIN NEW_Y NEW_X

‘zcurses’ ‘clear’ TARGETWIN [ ‘redraw’ | ‘eol’ | ‘bot’ ]

‘zcurses’ ‘position’ TARGETWIN ARRAY

‘zcurses’ ‘char’ TARGETWIN CHARACTER

‘zcurses’ ‘string’ TARGETWIN STRING

‘zcurses’ ‘border’ TARGETWIN BORDER

‘zcurses’ ‘attr’ TARGETWIN [ [‘+|-’]:var:‘attribute’ | FG_COL‘/’BG_COL ]
[…]

‘zcurses’ ‘bg’ TARGETWIN [ [‘+|-’]:var:‘attribute’ | FG_COL‘/’BG_COL |
‘@’CHAR ] […]

‘zcurses’ ‘scroll’ TARGETWIN [ ‘on’ | ‘off’ | [‘+|-’]:var:‘lines’ ]

‘zcurses’ ‘input’ TARGETWIN [ PARAM [ KPARAM [ MPARAM ] ] ]

‘zcurses’ ‘mouse’ [ ‘delay’ NUM | [‘+|-]motion’ ]

‘zcurses’ ‘timeout’ TARGETWIN INTVAL

‘zcurses’ ‘querychar’ TARGETWIN [ PARAM ]

‘zcurses’ ‘resize’ HEIGHT WIDTH [ ‘endwin’ | ‘nosave’ | ‘endwin_nosave’
]

     Manipulate curses windows.  All uses of this command should be
     bracketed by ‘zcurses init’ to initialise use of curses, and
     ‘zcurses end’ to end it; omitting ‘zcurses end’ can cause the
     terminal to be in an unwanted state.

     The subcommand ‘addwin’ creates a window with NLINES lines and
     NCOLS columns.  Its upper left corner will be placed at row BEGIN_Y
     and column BEGIN_X of the screen.  TARGETWIN is a string and refers
     to the name of a window that is not currently assigned.  Note in
     particular the curses convention that vertical values appear before
     horizontal values.

     If ‘addwin’ is given an existing window as the final argument, the
     new window is created as a subwindow of PARENTWIN.  This differs
     from an ordinary new window in that the memory of the window
     contents is shared with the parent’s memory.  Subwindows must be
     deleted before their parent.  Note that the coordinates of
     subwindows are relative to the screen, not the parent, as with
     other windows.

     Use the subcommand ‘delwin’ to delete a window created with
     ‘addwin’.  Note that ‘end’ does ‘not’ implicitly delete windows,
     and that ‘delwin’ does not erase the screen image of the window.

     The window corresponding to the full visible screen is called
     ‘stdscr’; it always exists after ‘zcurses init’ and cannot be
     delete with ‘delwin’.

     The subcommand ‘refresh’ will refresh window TARGETWIN; this is
     necessary to make any pending changes (such as characters you have
     prepared for output with ‘char’) visible on the screen.  ‘refresh’
     without an argument causes the screen to be cleared and redrawn.
     If multiple windows are given, the screen is updated once at the
     end.

     The subcommand ‘touch’ marks the TARGETWINs listed as changed.
     This is necessary before ‘refresh’ing windows if a window that was
     in front of another window (which may be ‘stdscr’) is deleted.

     The subcommand ‘move’ moves the cursor position in TARGETWIN to new
     coordinates NEW_Y and NEW_X.  Note that the subcommand ‘string’
     (but not the subcommand ‘char’) advances the cursor position over
     the characters added.

     The subcommand ‘clear’ erases the contents of TARGETWIN.  One (and
     no more than one) of three options may be specified.  With the
     option ‘redraw’, in addition the next ‘refresh’ of TARGETWIN will
     cause the screen to be cleared and repainted.  With the option
     ‘eol’, TARGETWIN is only cleared to the end of the current cursor
     line.  With the option ‘bot’, TARGETWIN is cleared to the end of
     the window, i.e everything to the right and below the cursor is
     cleared.

     The subcommand ‘position’ writes various positions associated with
     TARGETWIN into the array named ARRAY.  These are, in order:

        - The y and x coordinates of the cursor relative to the top left
          of TARGETWIN

        - The y and x coordinates of the top left of TARGETWIN on the
          screen

        - The size of TARGETWIN in y and x dimensions.

     Outputting characters and strings are achieved by ‘char’ and
     ‘string’ respectively.

     To draw a border around window TARGETWIN, use ‘border’.  Note that
     the border is not subsequently handled specially: in other words,
     the border is simply a set of characters output at the edge of the
     window.  Hence it can be overwritten, can scroll off the window,
     etc.

     The subcommand ‘attr’ will set TARGETWIN’s attributes or
     foreground/background color pair for any successive character
     output.  Each ATTRIBUTE given on the line may be prepended by a ‘+’
     to set or a ‘-’ to unset that attribute; ‘+’ is assumed if absent.
     The attributes supported are ‘blink’, ‘bold’, ‘dim’, ‘reverse’,
     ‘standout’, and ‘underline’.

     Each FG_COL‘/’BG_COL attribute (to be read as FG_COL on BG_COL)
     sets the foreground and background color for character output.  The
     color ‘default’ is sometimes available (in particular if the
     library is ncurses), specifying the foreground or background color
     with which the terminal started.  The color pair ‘default/default’
     is always available.  To use more than the 8 named colors (red,
     green, etc.)  construct the FG_COL‘/’BG_COL pairs where FG_COL and
     BG_COL are decimal integers, e.g ‘128/200’.  The maximum color
     value is 254 if the terminal supports 256 colors.

     ‘bg’ overrides the color and other attributes of all characters in
     the window.  Its usual use is to set the background initially, but
     it will overwrite the attributes of any characters at the time when
     it is called.  In addition to the arguments allowed with ‘attr’, an
     argument ‘@’CHAR specifies a character to be shown in otherwise
     blank areas of the window.  Owing to limitations of curses this
     cannot be a multibyte character (use of ASCII characters only is
     recommended).  As the specified set of attributes override the
     existing background, turning attributes off in the arguments is not
     useful, though this does not cause an error.

     The subcommand ‘scroll’ can be used with ‘on’ or ‘off’ to enabled
     or disable scrolling of a window when the cursor would otherwise
     move below the window due to typing or output.  It can also be used
     with a positive or negative integer to scroll the window up or down
     the given number of lines without changing the current cursor
     position (which therefore appears to move in the opposite direction
     relative to the window).  In the second case, if scrolling is ‘off’
     it is temporarily turned ‘on’ to allow the window to be scrolled.

     The subcommand ‘input’ reads a single character from the window
     without echoing it back.  If PARAM is supplied the character is
     assigned to the parameter PARAM, else it is assigned to the
     parameter ‘REPLY’.

     If both PARAM and KPARAM are supplied, the key is read in ‘keypad’
     mode.  In this mode special keys such as function keys and arrow
     keys return the name of the key in the parameter KPARAM.  The key
     names are the macros defined in the ‘curses.h’ or ‘ncurses.h’ with
     the prefix ‘KEY_’ removed; see also the description of the
     parameter ‘zcurses_keycodes’ below.  Other keys cause a value to be
     set in PARAM as before.  On a successful return only one of PARAM
     or KPARAM contains a non-empty string; the other is set to an empty
     string.

     If MPARAM is also supplied, ‘input’ attempts to handle mouse input.
     This is only available with the ncurses library; mouse handling can
     be detected by checking for the exit status of ‘zcurses mouse’ with
     no arguments.  If a mouse button is clicked (or double- or
     triple-clicked, or pressed or released with a configurable delay
     from being clicked) then KPARAM is set to the string ‘MOUSE’, and
     MPARAM is set to an array consisting of the following elements:

        - An identifier to discriminate different input devices; this is
          only rarely useful.

        - The x, y and z coordinates of the mouse click relative to the
          full screen, as three elements in that order (i.e.  the y
          coordinate is, unusually, after the x coordinate).  The z
          coordinate is only available for a few unusual input devices
          and is otherwise set to zero.

        - Any events that occurred as separate items; usually there will
          be just one.  An event consists of ‘PRESSED’, ‘RELEASED’,
          ‘CLICKED’, ‘DOUBLE_CLICKED’ or ‘TRIPLE_CLICKED’ followed
          immediately (in the same element) by the number of the button.

        - If the shift key was pressed, the string ‘SHIFT’.

        - If the control key was pressed, the string ‘CTRL’.

        - If the alt key was pressed, the string ‘ALT’.

     Not all mouse events may be passed through to the terminal window;
     most terminal emulators handle some mouse events themselves.  Note
     that the ncurses manual implies that using input both with and
     without mouse handling may cause the mouse cursor to appear and
     disappear.

     The subcommand ‘mouse’ can be used to configure the use of the
     mouse.  There is no window argument; mouse options are global.
     ‘zcurses mouse’ with no arguments returns status 0 if mouse
     handling is possible, else status 1.  Otherwise, the possible
     arguments (which may be combined on the same command line) are as
     follows.  ‘delay’ NUM sets the maximum delay in milliseconds
     between press and release events to be considered as a click; the
     value 0 disables click resolution, and the default is one sixth of
     a second.  ‘motion’ proceeded by an optional ‘+’ (the default) or
     ‘-’ turns on or off reporting of mouse motion in addition to
     clicks, presses and releases, which are always reported.  However,
     it appears reports for mouse motion are not currently implemented.

     The subcommand ‘timeout’ specifies a timeout value for input from
     TARGETWIN.  If INTVAL is negative, ‘zcurses input’ waits
     indefinitely for a character to be typed; this is the default.  If
     INTVAL is zero, ‘zcurses input’ returns immediately; if there is
     typeahead it is returned, else no input is done and status 1 is
     returned.  If INTVAL is positive, ‘zcurses input’ waits INTVAL
     milliseconds for input and if there is none at the end of that
     period returns status 1.

     The subcommand ‘querychar’ queries the character at the current
     cursor position.  The return values are stored in the array named
     PARAM if supplied, else in the array ‘reply’.  The first value is
     the character (which may be a multibyte character if the system
     supports them); the second is the color pair in the usual
     FG_COL‘/’BG_COL notation, or ‘0’ if color is not supported.  Any
     attributes other than color that apply to the character, as set
     with the subcommand ‘attr’, appear as additional elements.

     The subcommand ‘resize’ resizes ‘stdscr’ and all windows to given
     dimensions (windows that stick out from the new dimensions are
     resized down).  The underlying curses extension (‘resize_term
     call’) can be unavailable.  To verify, zeroes can be used for
     HEIGHT and WIDTH.  If the result of the subcommand is ‘0’,
     resize_term is available (‘2’ otherwise).  Tests show that resizing
     can be normally accomplished by calling ‘zcurses end’ and ‘zcurses
     refresh’.  The ‘resize’ subcommand is provided for versatility.
     Multiple system configurations have been checked and ‘zcurses end’
     and ‘zcurses refresh’ are still needed for correct terminal state
     after resize.  To invoke them with ‘resize’, use ENDWIN argument.
     Using NOSAVE argument will cause new terminal state to not be saved
     internally by ‘zcurses’.  This is also provided for versatility and
     should normally be not needed.


File: zsh.info,  Node: Parameters<2>,  Prev: Builtin,  Up: The zsh/curses Module

21.9.2 Parameters
-----------------

‘ZCURSES_COLORS’

     Readonly integer.  The maximum number of colors the terminal
     supports.  This value is initialised by the curses library and is
     not available until the first time ‘zcurses init’ is run.

‘ZCURSES_COLOR_PAIRS’

     Readonly integer.  The maximum number of color pairs
     FG_COL‘/’BG_COL that may be defined in ‘zcurses attr’ commands;
     note this limit applies to all color pairs that have been used
     whether or not they are currently active.  This value is
     initialised by the curses library and is not available until the
     first time ‘zcurses init’ is run.

‘zcurses_attrs’

     Readonly array.  The attributes supported by ‘zsh/curses’;
     available as soon as the module is loaded.

‘zcurses_colors’

     Readonly array.  The colors supported by ‘zsh/curses’; available as
     soon as the module is loaded.

‘zcurses_keycodes’

     Readonly array.  The values that may be returned in the second
     parameter supplied to ‘zcurses input’ in the order in which they
     are defined internally by curses.  Not all function keys are
     listed, only ‘F0’; curses reserves space for ‘F0’ up to ‘F63’.

‘zcurses_windows’

     Readonly array.  The current list of windows, i.e.  all windows
     that have been created with ‘zcurses addwin’ and not removed with
     ‘zcurses delwin’.


File: zsh.info,  Node: The zsh/datetime Module,  Next: The zsh/db/gdbm Module,  Prev: The zsh/curses Module,  Up: Zsh Modules

21.10 The zsh/datetime Module
=============================

The ‘zsh/datetime’ module makes available one builtin command:

‘strftime’ [ ‘-s’ SCALAR | ‘-n’ ] FORMAT [ EPOCHTIME [ NANOSECONDS ] ]

‘strftime’ ‘-r’ [ ‘-q’ ] [ ‘-s’ SCALAR | ‘-n’ ] FORMAT TIMESTRING

     Output the date in the FORMAT specified.  With no EPOCHTIME, the
     current system date/time is used; optionally, EPOCHTIME may be used
     to specify the number of seconds since the epoch, and NANOSECONDS
     may additionally be used to specify the number of nanoseconds past
     the second (otherwise that number is assumed to be 0).  See
     ‘strftime(3)’ for details.  The zsh extensions described under
     ‘%D{’STRING‘}’ prompt eqcape in *note Simple Prompt Escapes: 131.
     are also available.

     ‘-n’

          Suppress printing a newline after the formatted string.

     ‘-q’

          Run quietly; suppress printing of all error messages described
          below.  Errors for invalid EPOCHTIME values are always
          printed.

     ‘-r’

          With the option ‘-r’ (reverse), use FORMAT to parse the input
          string TIMESTRING and output the number of seconds since the
          epoch at which the time occurred.  The parsing is implemented
          by the system function ‘strptime’; see ‘strptime(3)’.  This
          means that zsh format extensions are not available, but for
          reverse lookup they are not required.

          In most implementations of ‘strptime’ any timezone in the
          TIMESTRING is ignored and the local timezone declared by the
          ‘TZ’ environment variable is used; other parameters are set to
          zero if not present.

          If TIMESTRING does not match FORMAT the command returns status
          1 and prints an error message.  If TIMESTRING matches FORMAT
          but not all characters in TIMESTRING were used, the conversion
          succeeds but also prints an error message.

          If either of the system functions ‘strptime’ or ‘mktime’ is
          not available, status 2 is returned and an error message is
          printed.

     ‘-s’ SCALAR

          Assign the date string (or epoch time in seconds if ‘-r’ is
          given) to SCALAR instead of printing it.

     Note that depending on the system’s declared integral time type,
     ‘strftime’ may produce incorrect results for epoch times greater
     than 2147483647 which corresponds to 2038-01-19 03:14:07 +0000.

The ‘zsh/datetime’ module makes available several parameters; all are
readonly:

‘EPOCHREALTIME’

     A floating point value representing the number of seconds since the
     epoch.  The notional accuracy is to nanoseconds if the
     ‘clock_gettime’ call is available and to microseconds otherwise,
     but in practice the range of double precision floating point and
     shell scheduling latencies may be significant effects.

‘EPOCHSECONDS’

     An integer value representing the number of seconds since the
     epoch.

‘epochtime’

     An array value containing the number of seconds since the epoch in
     the first element and the remainder of the time since the epoch in
     nanoseconds in the second element.  To ensure the two elements are
     consistent the array should be copied or otherwise referenced as a
     single substitution before the values are used.  The following
     idiom may be used:

           for secs nsecs in $epochtime; do
             ...
           done


File: zsh.info,  Node: The zsh/db/gdbm Module,  Next: The zsh/deltochar Module,  Prev: The zsh/datetime Module,  Up: Zsh Modules

21.11 The zsh/db/gdbm Module
============================

The ‘zsh/db/gdbm’ module is used to create “tied” associative arrays
that interface to database files.  If the GDBM interface is not
available, the builtins defined by this module will report an error.
This module is also intended as a prototype for creating additional
database interfaces, so the ‘ztie’ builtin may move to a more generic
module in the future.

The builtins in this module are:

‘ztie -d db/gdbm -f’ FILENAME [ ‘-r’ ] ARRAYNAME

     Open the GDBM database identified by FILENAME and, if successful,
     create the associative array ARRAYNAME linked to the file.  To
     create a local tied array, the parameter must first be declared, so
     commands similar to the following would be executed inside a
     function scope:

           local -A sampledb
           ztie -d db/gdbm -f sample.gdbm sampledb

     The ‘-r’ option opens the database file for reading only, creating
     a parameter with the readonly attribute.  Without this option,
     using ‘ztie’ on a file for which the user does not have write
     permission is an error.  If writable, the database is opened
     synchronously so fields changed in ARRAYNAME are immediately
     written to FILENAME.

     Changes to the file modes FILENAME after it has been opened do not
     alter the state of ARRAYNAME, but ‘typeset -r’ ARRAYNAME works as
     expected.

‘zuntie’ [ ‘-u’ ] ARRAYNAME …

     Close the GDBM database associated with each ARRAYNAME and then
     unset the parameter.  The ‘-u’ option forces an unset of parameters
     made readonly with ‘ztie -r’.

     This happens automatically if the parameter is explicitly unset or
     its local scope (function) ends.  Note that a readonly parameter
     may not be explicitly unset, so the only way to unset a global
     parameter created with ‘ztie -r’ is to use ‘zuntie -u’.

‘zgdbmpath’ PARAMETERNAME

     Put path to database file assigned to PARAMETERNAME into ‘REPLY’
     scalar.

‘zgdbm_tied’

     Array holding names of all tied parameters.

The fields of an associative array tied to GDBM are neither cached nor
otherwise stored in memory, they are read from or written to the
database on each reference.  Thus, for example, the values in a readonly
array may be changed by a second writer of the same database file.


File: zsh.info,  Node: The zsh/deltochar Module,  Next: The zsh/example Module,  Prev: The zsh/db/gdbm Module,  Up: Zsh Modules

21.12 The zsh/deltochar Module
==============================

The ‘zsh/deltochar’ module makes available two ZLE functions:

‘delete-to-char’

     Read a character from the keyboard, and delete from the cursor
     position up to and including the next (or, with repeat count N, the
     Nth) instance of that character.  Negative repeat counts mean
     delete backwards.

‘zap-to-char’

     This behaves like ‘delete-to-char’, except that the final
     occurrence of the character itself is not deleted.


File: zsh.info,  Node: The zsh/example Module,  Next: The zsh/files Module,  Prev: The zsh/deltochar Module,  Up: Zsh Modules

21.13 The zsh/example Module
============================

The ‘zsh/example’ module makes available one builtin command:

‘example’ [ ‘-flags’ ] [ ARGS … ]

     Displays the flags and arguments it is invoked with.

The purpose of the module is to serve as an example of how to write a
module.


File: zsh.info,  Node: The zsh/files Module,  Next: The zsh/hlgroup Module,  Prev: The zsh/example Module,  Up: Zsh Modules

21.14 The zsh/files Module
==========================

The ‘zsh/files’ module makes available some common commands for file
manipulation as builtins; these commands are probably not needed for
many normal situations but can be useful in emergency recovery
situations with constrained resources.  The commands do not implement
all features now required by relevant standards committees.

For all commands, a variant beginning ‘zf_’ is also available and loaded
automatically.  Using the features capability of zmodload will let you
load only those names you want.  Note that it’s possible to load only
the builtins with zsh-specific names using the following command:

      zmodload -m -F zsh/files b:zf_\*

The commands loaded by default are:

‘chgrp’ [ ‘-hRs’ ] GROUP FILENAME …

     Changes group of files specified.  This is equivalent to ‘chown’
     with a USER-SPEC argument of ‘:’GROUP.

‘chmod’ [ ‘-Rs’ ] MODE FILENAME …

     Changes mode of files specified.

     The specified MODE must be in octal.

     The ‘-R’ option causes ‘chmod’ to recursively descend into
     directories, changing the mode of all files in the directory after
     changing the mode of the directory itself.

     The ‘-s’ option is a zsh extension to ‘chmod’ functionality.  It
     enables paranoid behaviour, intended to avoid security problems
     involving a ‘chmod’ being tricked into affecting files other than
     the ones intended.  It will refuse to follow symbolic links, so
     that (for example) ‘`chmod 600 /tmp/foo/passwd’’ can’t accidentally
     chmod ‘/etc/passwd’ if ‘/tmp/foo’ happens to be a link to ‘/etc’.
     It will also check where it is after leaving directories, so that a
     recursive chmod of a deep directory tree can’t end up recursively
     chmoding ‘/usr’ as a result of directories being moved up the tree.

‘chown’ [ ‘-hRs’ ] USER-SPEC FILENAME …

     Changes ownership and group of files specified.

     The USER-SPEC can be in four forms:

     USER

          change owner to USER; do not change group

     USER‘::’

          change owner to USER; do not change group

     USER‘:’

          change owner to USER; change group to USER’s primary group

     USER‘:’GROUP

          change owner to USER; change group to GROUP

     ‘:’GROUP

          do not change owner; change group to GROUP

     In each case, the ‘:’ may instead be a ‘.’.  The rule is that if
     there is a ‘:’ then the separator is ‘:’, otherwise if there is a
     ‘.’ then the separator is ‘.’, otherwise there is no separator.

     Each of USER and GROUP may be either a username (or group name, as
     appropriate) or a decimal user ID (group ID). Interpretation as a
     name takes precedence, if there is an all-numeric username (or
     group name).

     If the target is a symbolic link, the ‘-h’ option causes ‘chown’ to
     set the ownership of the link instead of its target.

     The ‘-R’ option causes ‘chown’ to recursively descend into
     directories, changing the ownership of all files in the directory
     after changing the ownership of the directory itself.

     The ‘-s’ option is a zsh extension to ‘chown’ functionality.  It
     enables paranoid behaviour, intended to avoid security problems
     involving a ‘chown’ being tricked into affecting files other than
     the ones intended.  It will refuse to follow symbolic links, so
     that (for example) ‘`chown luser /tmp/foo/passwd’’ can’t
     accidentally chown ‘/etc/passwd’ if ‘/tmp/foo’ happens to be a link
     to ‘/etc’.  It will also check where it is after leaving
     directories, so that a recursive chown of a deep directory tree
     can’t end up recursively chowning ‘/usr’ as a result of directories
     being moved up the tree.

‘ln’ [ ‘-dfhins’ ] FILENAME DEST

‘ln’ [ ‘-dfhins’ ] FILENAME … DIR

     Creates hard (or, with ‘-s’, symbolic) links.  In the first form,
     the specified DESTination is created, as a link to the specified
     FILENAME.  In the second form, each of the FILENAMEs is taken in
     turn, and linked to a pathname in the specified DIRectory that has
     the same last pathname component.

     Normally, ‘ln’ will not attempt to create hard links to
     directories.  This check can be overridden using the ‘-d’ option.
     Typically only the super-user can actually succeed in creating hard
     links to directories.  This does not apply to symbolic links in any
     case.

     By default, existing files cannot be replaced by links.  The ‘-i’
     option causes the user to be queried about replacing existing
     files.  The ‘-f’ option causes existing files to be silently
     deleted, without querying.  ‘-f’ takes precedence.

     The ‘-h’ and ‘-n’ options are identical and both exist for
     compatibility; either one indicates that if the target is a symlink
     then it should not be dereferenced.  Typically this is used in
     combination with ‘-sf’ so that if an existing link points to a
     directory then it will be removed, instead of followed.  If this
     option is used with multiple filenames and the target is a symbolic
     link pointing to a directory then the result is an error.

‘mkdir’ [ ‘-p’ ] [ ‘-m’ MODE ] DIR …

     Creates directories.  With the ‘-p’ option, non-existing parent
     directories are first created if necessary, and there will be no
     complaint if the directory already exists.  The ‘-m’ option can be
     used to specify (in octal) a set of file permissions for the
     created directories, otherwise mode 777 modified by the current
     ‘umask’ (see ‘umask(2)’) is used.

‘mv’ [ ‘-fi’ ] FILENAME DEST

‘mv’ [ ‘-fi’ ] FILENAME … DIR

     Moves files.  In the first form, the specified FILENAME is moved to
     the specified DESTination.  In the second form, each of the
     FILENAMEs is taken in turn, and moved to a pathname in the
     specified DIRectory that has the same last pathname component.

     By default, the user will be queried before replacing any file that
     the user cannot write to, but writable files will be silently
     removed.  The ‘-i’ option causes the user to be queried about
     replacing any existing files.  The ‘-f’ option causes any existing
     files to be silently deleted, without querying.  ‘-f’ takes
     precedence.

     Note that this ‘mv’ will not move files across devices.  Historical
     versions of ‘mv’, when actual renaming is impossible, fall back on
     copying and removing files; if this behaviour is desired, use ‘cp’
     and ‘rm’ manually.  This may change in a future version.

‘rm’ [ ‘-dfiRrs’ ] FILENAME …

     Removes files and directories specified.

     Normally, ‘rm’ will not remove directories (except with the ‘-R’ or
     ‘-r’ options).  The ‘-d’ option causes ‘rm’ to try removing
     directories with ‘unlink’ (see ‘unlink(2)’), the same method used
     for files.  Typically only the super-user can actually succeed in
     unlinking directories in this way.  ‘-d’ takes precedence over ‘-R’
     and ‘-r’.

     By default, the user will be queried before removing any file that
     the user cannot write to, but writable files will be silently
     removed.  The ‘-i’ option causes the user to be queried about
     removing any files.  The ‘-f’ option causes files to be silently
     deleted, without querying, and suppresses all error indications.
     ‘-f’ takes precedence.

     The ‘-R’ and ‘-r’ options cause ‘rm’ to recursively descend into
     directories, deleting all files in the directory before removing
     the directory with the ‘rmdir’ system call (see ‘rmdir(2)’).

     The ‘-s’ option is a zsh extension to ‘rm’ functionality.  It
     enables paranoid behaviour, intended to avoid common security
     problems involving a root-run ‘rm’ being tricked into removing
     files other than the ones intended.  It will refuse to follow
     symbolic links, so that (for example) ‘`rm /tmp/foo/passwd’’ can’t
     accidentally remove ‘/etc/passwd’ if ‘/tmp/foo’ happens to be a
     link to ‘/etc’.  It will also check where it is after leaving
     directories, so that a recursive removal of a deep directory tree
     can’t end up recursively removing ‘/usr’ as a result of directories
     being moved up the tree.

‘rmdir’ DIR …

     Removes empty directories specified.

‘sync’

     Calls the system call of the same name (see ‘sync(2)’), which
     flushes dirty buffers to disk.  It might return before the I/O has
     actually been completed.


File: zsh.info,  Node: The zsh/hlgroup Module,  Next: The zsh/langinfo Module,  Prev: The zsh/files Module,  Up: Zsh Modules

21.15 The zsh/hlgroup Module
============================

The ‘zsh/hlgroup’ module defines special parameters that represent
highlighting groups in different forms to ease the use of the groups
when configuring other tools.

In each case, these are readonly associative arrays where accessing
elements uses values from the underlying ‘.zle.hlgroups’ variable.

‘.zle.esc’

     This associative array contains the literal escape sequences used
     to apply the highlighting for each group.  An example use would be
     when setting the ‘LESS_TERMCAP_xx’ environment variables for the
     ‘less’ pager.

‘.zle.sgr’

     Where highlighting makes use of CSI escape sequences, this
     parameter contains the “Select Graphic Rendition” number sequence.
     This is useful with, for example the ‘GREP_COLORS’ and ‘LSCOLORS’
     environment variables and the ‘list-colors’ style.


File: zsh.info,  Node: The zsh/langinfo Module,  Next: The zsh/ksh93 Module,  Prev: The zsh/hlgroup Module,  Up: Zsh Modules

21.16 The zsh/langinfo Module
=============================

The ‘zsh/langinfo’ module makes available one parameter:

‘langinfo’

     An associative array that maps langinfo elements to their values.

     Your implementation may support a number of the following keys:

     ‘CODESET’, ‘D_T_FMT’, ‘D_FMT’, ‘T_FMT’, ‘RADIXCHAR’, ‘THOUSEP’,
     ‘YESEXPR’, ‘NOEXPR’, ‘CRNCYSTR’, ‘ABDAY_{1..7}’, ‘DAY_{1..7}’,
     ‘ABMON_{1..12}’, ‘MON_{1..12}’, ‘T_FMT_AMPM’, ‘AM_STR’, ‘PM_STR’,
     ‘ERA’, ‘ERA_D_FMT’, ‘ERA_D_T_FMT’, ‘ERA_T_FMT’, ‘ALT_DIGITS’


File: zsh.info,  Node: The zsh/ksh93 Module,  Next: The zsh/mapfile Module,  Prev: The zsh/langinfo Module,  Up: Zsh Modules

21.17 The zsh/ksh93 Module
==========================

The ‘zsh/ksh93’ module provides one builtin and several parameters to
improve compatibility with ksh93.  As of this writing, several ksh93
features are still missing.

* Menu:

* Ksh Builtins::
* Ksh Parameters::
* Future Compatibility::
* Other Differences::


File: zsh.info,  Node: Ksh Builtins,  Next: Ksh Parameters,  Up: The zsh/ksh93 Module

21.17.1 Ksh Builtins
--------------------

The single builtin provided by this module is:

‘nameref’ [ ‘-gpur’ ] PNAME[‘=’RNAME]

     Equivalent to ‘typeset -n’ PNAME‘=’RNAME

     However, ‘nameref’ is a builtin command rather than a reserved
     word, so handling of assigments in the argument list may differ.


File: zsh.info,  Node: Ksh Parameters,  Next: Future Compatibility,  Prev: Ksh Builtins,  Up: The zsh/ksh93 Module

21.17.2 Ksh Parameters
----------------------

Parameters supplied by this module that are marked with ‘<K>’ below are
available only when ksh emulation is active before entry to the shell
function, that is, ‘emulate ksh’ locally to a function does not populate
these parameters for that function.

‘.sh.command’

     A named reference to ‘ZSH_DEBUG_CMD’

‘.sh.edchar’ <K>

     In a ZLE widget, equivalent to the ‘KEYS’ special parameter.  In a
     future release, assignments to this parameter will affect the input
     stream seen by ZLE.

‘.sh.edcol’

     A named reference to the ZLE special parameter ‘CURSOR’.

‘.sh.edmode’ <K>

     In a ZLE widget, this parameter has the value ‘ESC’ (‘$'\e'’) if
     the ‘VI’ option is set and the ‘main’ keymap is selected.  This is
     intended for use with vi-mode key bindings (‘bindkey -v’).  In a
     future revision, assigning ‘.sh.edchar=${.sh.edmode}’ is expected
     to initiate ‘vicmd’ mode when ‘viins’ is active, and do nothing
     when ‘vicmd’ is already active.

‘.sh.edtext’

     A named reference to the ‘BUFFER’ special ZLE parameter.

‘.sh.file’

     A named reference to the ‘ZSH_SCRIPT’ parameter.

‘.sh.fun’ <K>

     In a shell function, the function’s name.  Usually the same as
     ‘$0’, but not affected by ‘POSIX_ARGZERO’ or ‘FUNCTION_ARGZERO’
     options.

‘.sh.level’ <K>

     In a shell function, initially set to the depth of the call stack.
     This may be assigned to change the apparent depth.  However, such
     assignment does not affect the scope of local parameters.

‘.sh.lineno’

     A named reference to the ‘LINENO’ special parameter.

‘.sh.match’

     An array equivalent to the ‘match’ parameter as assigned by the
     ‘(#b)’ extended globbing flag.  When the ‘KSH_ARRAYS’ option is
     set, ‘${.sh.match[0]}’ gives the value of the ‘MATCH’ parameter as
     set by the ‘(#m)’ extended globbing flag.  Currently, the
     ‘EXTENDED_GLOB’ option must be enabled and those flags must be
     explicitly used in a pattern in order for these values of
     ‘.sh.match’ to be set.

‘.sh.name’ <K>

     When the ‘vared’ command is used, this parameter may be used in
     user-defined ZLE widgets to get the name of the variable being
     edited.  A future release is expected to use this parameter in the
     implementation of “discipline functions”.

‘.sh.subscript’ <K>

     When ‘vared’ has been used on an array element, this parameter
     holds the array index (either a number, or an associative array
     key).

‘.sh.subshell’

     A named reference to the ‘ZSH_SUBSHELL’ parameter.

‘.sh.value’ <K>

     In ‘vared’ this is a named reference to the ZLE special ‘BUFFER’.
     A future release is expected to use this parameter in the
     implementation of “discipline functions”.

‘.sh.version’

     A named reference to ‘ZSH_PATCHLEVEL’.


File: zsh.info,  Node: Future Compatibility,  Next: Other Differences,  Prev: Ksh Parameters,  Up: The zsh/ksh93 Module

21.17.3 Future Compatibility
----------------------------

The following features of ksh93 are not currently supported but may be
available in a future release.

‘namespace’ IDENT ‘{’ LIST ‘}’

     This reserved word executes the current shell compound command ‘{’
     LIST ‘}’, with the special behavior that all functions and
     parameters NAME declared within LIST are implicitly prefixed to
     become ‘.’IDENT‘.’NAME, and similarly any reference to a function
     or parameter NAME is searched for as ‘.’IDENT‘.’NAME before falling
     back to NAME.

     ‘THIS FEATURE IS NOT YET IMPLEMENTED.’

‘.sh.math’ <K>

     This parameter is more accurately considered a namespace.  A
     function definition of the form

          ‘function .sh.math.’NAME IDENT ‘... {’ LIST ‘}’

     is equivalent to the native zsh definition

           function NAME {
             local IDENT=$1 ...
             LIST
           }
           functions -M NAME 1 3

     Up to 3 IDENT arguments, interpreted as floating point numbers, may
     be provided for a function defined with ‘.sh.math’ in this way.
     The names (but not definitions) of all such functions are available
     via ‘${.sh.math[@]}’.

     ‘THIS FEATURE IS NOT YET IMPLEMENTED.’

‘:var:`name’‘.get‘‘‘‘

     A shell function having this name, if defined, is invoked whenever
     the parameter ‘${’NAME‘}’ is referenced, including by commands such
     as ‘typeset -p’.  If the special variable ‘.sh.value’ is assigned
     by the function, that value is substituted instead of the true
     value of NAME.  This does not change the value of NAME, but there
     is no way to access the actual value without first removing the
     function.

     Additionally, an explicit reference to ‘${’NAME‘.get}’ calls the
     function NAME‘.get’ even if there is no parameter NAME and
     substitutes the standard output of the function.

     ‘THIS FEATURE IS NOT YET IMPLEMENTED.’

‘:var:`name’‘.set‘‘‘‘

‘:var:`name’‘.append‘‘‘‘

     Shell functions having these names are invoked when the parameter
     NAME is assigned or (for array types) has a new field appended.
     The function may change the result of the operation by assigning to
     the ‘.sh.value’ special parameter, or block the change by unsetting
     ‘.sh.value’.

     Explicit reference to ‘${’NAME‘.set}’ or ‘${’NAME‘.append}’
     substitutes the standard output of the function.

     ‘THIS FEATURE IS NOT YET IMPLEMENTED.’

‘:var:`name’‘.unset‘‘‘‘

     When a function of this name is defined, it is called whenever the
     parameter NAME would be unset.  The function must explicitly
     ‘unset’ NAME, otherwise the variable remains set.

     ‘THIS FEATURE IS NOT YET IMPLEMENTED.’

‘typeset -C’ NAME[‘=’VALUES ‘...’]

     Creates a ‘compound variable’.

     ‘THIS FEATURE IS NOT YET IMPLEMENTED, and the syntax of
     :var:’values‘ is unlikely to be fully ksh compatible.‘


File: zsh.info,  Node: Other Differences,  Prev: Future Compatibility,  Up: The zsh/ksh93 Module

21.17.4 Other Differences
-------------------------

The following features of ksh93 are not currently supported and there
are no plans to implement them.

PATHDIR‘/.paths’

     Each directory PATHDIR in the ‘PATH’ parameter may contain a text
     file ‘.paths’ which may define additional directories to be
     searched for function definitions (‘FPATH’), external executables
     (‘PATH’), and plugin files (similar to ‘MODULE_PATH’).

     ‘THIS FEATURE IS UNLIKELY EVER TO BE IMPLEMENTED.’

‘builtin -f’ FILE

     Installs a new shell builtin command dynamically linked from FILE,
     where FILE is found by a path search and the base name of the file
     is the name of the builtin to be added.

     Similar to ‘zmodload -F zsh/’FILE ‘+b:’FILE.

     ‘THIS FEATURE IS UNLIKELY EVER TO BE IMPLEMENTED.’

‘typeset -H’ NAME[‘=’VALUE]

     Used for ‘host-name file mapping’ on some operating systems.

     ‘THIS FEATURE IS UNLIKELY EVER TO BE IMPLEMENTED.’

‘typeset {+|-}M’ MAPNAME NAME[‘=’VALUE]

     Declares a character translation MAPNAME for values assigned to
     NAME.

‘typeset -S’

‘typeset -T’ [‘-f’] [ TNAME‘=(’VALUES‘)’ ]

‘typeset -h’ STR

     Used to define ‘typed variables’ and properties of their
     ‘sub-variables’.  The ‘-T’ and ‘-h’ options conflict with existing
     zsh usage.

‘typeset -X’ NAME[‘=’VALUE]

     Declares a floating-point variable displayed in hexadecimal format.

‘typeset -b’ NAME[‘=’VALUE]

     Declares a parameter stored in ‘base64’ format.

‘typeset -m’ NEWNAME‘=’OLDNAME

     ‘Moves’ OLDNAME to NEWNAME.  Conflicts with native zsh usage.


File: zsh.info,  Node: The zsh/mapfile Module,  Next: The zsh/mathfunc Module,  Prev: The zsh/ksh93 Module,  Up: Zsh Modules

21.18 The zsh/mapfile Module
============================

The ‘zsh/mapfile’ module provides one special associative array
parameter of the same name.

‘mapfile’

     This associative array takes as keys the names of files; the
     resulting value is the content of the file.  The value is treated
     identically to any other text coming from a parameter.  The value
     may also be assigned to, in which case the file in question is
     written (whether or not it originally existed); or an element may
     be unset, which will delete the file in question.  For example,
     ‘vared mapfile[myfile]'’’ works as expected, editing the file
     ‘myfile’.

     When the array is accessed as a whole, the keys are the names of
     files in the current directory, and the values are empty (to save a
     huge overhead in memory).  Thus ‘${(k)mapfile}’ has the same effect
     as the glob operator ‘*(D)’, since files beginning with a dot are
     not special.  Care must be taken with expressions such as ‘rm
     ${(k)mapfile}’, which will delete every file in the current
     directory without the usual ‘rm *’ test.

     The parameter ‘mapfile’ may be made read-only; in that case, files
     referenced may not be written or deleted.

     A file may conveniently be read into an array as one line per
     element with the form ARRAY‘=("${(f@)mapfile[’FILENAME‘]}")’.  The
     double quotes and the ‘@’ are necessary to prevent empty lines from
     being removed.  Note that if the file ends with a newline, the
     shell will split on the final newline, generating an additional
     empty field; this can be suppressed by using
     ARRAY‘=("${(f@)${mapfile[’FILENAME‘]%$\n'}}")’’.

* Menu:

* Limitations::


File: zsh.info,  Node: Limitations,  Up: The zsh/mapfile Module

21.18.1 Limitations
-------------------

Although reading and writing of the file in question is efficiently
handled, zsh’s internal memory management may be arbitrarily baroque;
however, ‘mapfile’ is usually very much more efficient than anything
involving a loop.  Note in particular that the whole contents of the
file will always reside physically in memory when accessed (possibly
multiple times, due to standard parameter substitution operations).  In
particular, this means handling of sufficiently long files (greater than
the machine’s swap space, or than the range of the pointer type) will be
incorrect.

No errors are printed or flagged for non-existent, unreadable, or
unwritable files, as the parameter mechanism is too low in the shell
execution hierarchy to make this convenient.

It is unfortunate that the mechanism for loading modules does not yet
allow the user to specify the name of the shell parameter to be given
the special behaviour.


File: zsh.info,  Node: The zsh/mathfunc Module,  Next: The zsh/nearcolor Module,  Prev: The zsh/mapfile Module,  Up: Zsh Modules

21.19 The zsh/mathfunc Module
=============================

The ‘zsh/mathfunc’ module provides standard mathematical functions for
use when evaluating mathematical formulae.  The syntax agrees with
normal C and FORTRAN conventions, for example,

      (( f = sin(0.3) ))

assigns the sine of 0.3 to the parameter f.

Most functions take floating point arguments and return a floating point
value.  However, any necessary conversions from or to integer type will
be performed automatically by the shell.  Apart from ‘atan’ with a
second argument and the ‘abs’, ‘int’ and ‘float’ functions, all
functions behave as noted in the manual page for the corresponding C
function, except that any arguments out of range for the function in
question will be detected by the shell and an error reported.

The following functions take a single floating point argument: ‘acos’,
‘acosh’, ‘asin’, ‘asinh’, ‘atan’, ‘atanh’, ‘cbrt’, ‘ceil’, ‘cos’,
‘cosh’, ‘erf’, ‘erfc’, ‘exp’, ‘expm1’, ‘fabs’, ‘floor’, ‘gamma’, ‘j0’,
‘j1’, ‘lgamma’, ‘log’, ‘log10’, ‘log1p’, ‘log2’, ‘logb’, ‘sin’, ‘sinh’,
‘sqrt’, ‘tan’, ‘tanh’, ‘y0’, ‘y1’.  The ‘atan’ function can optionally
take a second argument, in which case it behaves like the C function
‘atan2’.  The ‘ilogb’, ‘isinf’, and ‘isnan’ functions take a single
floating point argument, but return an integer.

The function ‘signgam’ takes no arguments, and returns an integer, which
is the C variable of the same name, as described in ‘gamma(3)’.  Note
that it is therefore only useful immediately after a call to ‘gamma’ or
‘lgamma’.  Note also that ‘signgam()’ and ‘signgam’ are distinct
expressions.

The functions ‘min’, ‘max’, and ‘sum’ are defined not in this module but
in the ‘zmathfunc’ autoloadable function, described in *note
Mathematical Functions: 140.

The following functions take two floating point arguments: ‘copysign’,
‘fmod’, ‘hypot’, ‘nextafter’.

The following take an integer first argument and a floating point second
argument: ‘jn’, ‘yn’.

The following take a floating point first argument and an integer second
argument: ‘ldexp’, ‘scalb’.

The function ‘abs’ does not convert the type of its single argument; it
returns the absolute value of either a floating point number or an
integer.  The functions ‘float’ and ‘int’ convert their arguments into a
floating point or integer value (by truncation) respectively.

Note that the C ‘pow’ function is available in ordinary math evaluation
as the ‘**’ operator and is not provided here.

The function ‘rand48’ is available if your system’s mathematical library
has the function ‘erand48(3)’.  It returns a pseudo-random floating
point number between 0 and 1.  It takes a single string optional
argument.

If the argument is not present, the random number seed is initialised by
three calls to the ‘rand(3)’ function — this produces the same random
numbers as the next three values of ‘$RANDOM’.

If the argument is present, it gives the name of a scalar parameter
where the current random number seed will be stored.  On the first call,
the value must contain at least twelve hexadecimal digits (the remainder
of the string is ignored), or the seed will be initialised in the same
manner as for a call to ‘rand48’ with no argument.  Subsequent calls to
‘rand48’(PARAM) will then maintain the seed in the parameter PARAM as a
string of twelve hexadecimal digits, with no base signifier.  The random
number sequences for different parameters are completely independent,
and are also independent from that used by calls to ‘rand48’ with no
argument.

For example, consider

      print $(( rand48(seed) ))
      print $(( rand48() ))
      print $(( rand48(seed) ))

Assuming ‘$seed’ does not exist, it will be initialised by the first
call.  In the second call, the default seed is initialised; note,
however, that because of the properties of ‘rand()’ there is a
correlation between the seeds used for the two initialisations, so for
more secure uses, you should generate your own 12-byte seed.  The third
call returns to the same sequence of random numbers used in the first
call, unaffected by the intervening ‘rand48()’.


File: zsh.info,  Node: The zsh/nearcolor Module,  Next: The zsh/newuser Module,  Prev: The zsh/mathfunc Module,  Up: Zsh Modules

21.20 The zsh/nearcolor Module
==============================

The ‘zsh/nearcolor’ module replaces colours specified as hex triplets
with the nearest colour in the 88 or 256 colour palettes that are widely
used by terminal emulators.  By default, 24-bit true colour escape codes
are generated when colours are specified using hex triplets.  These are
not supported by all terminals.  The purpose of this module is to make
it easier to define colour preferences in a form that can work across a
range of terminal emulators.

Aside from the default colour, the ANSI standard for terminal escape
codes provides for eight colours.  The bright attribute brings this to
sixteen.  These basic colours are commonly used in terminal applications
due to being widely supported.  Expanded 88 and 256 colour palettes are
also common and, while the first sixteen colours vary somewhat between
terminals and configurations, these add a generally consistent and
predictable set of colours.

In order to use the ‘zsh/nearcolor’ module, it only needs to be loaded.
Thereafter, whenever a colour is specified using a hex triplet, it will
be compared against each of the available colours and the closest will
be selected.  The first sixteen colours are never matched in this
process due to being unpredictable.

The use of a hex triplet will automatically load the ‘zsh/nearcolor’
module if the terminal doesn’t support 24-bit colour.  This behaviour
can be modified via the ‘.term.extensions’ parameter – see *note
Terminal Extensions: 98.

The module can also be loaded manually.  It is recommended to be
selective in doing so.  For example, the following checks the
‘COLORTERM’ environment variable:

      [[ $COLORTERM = *(24bit|truecolor)* ]] || zmodload zsh/nearcolor

Note that some terminals accept the true color escape codes but map them
internally to a more limited palette in a similar manner to the
‘zsh/nearcolor’ module.


File: zsh.info,  Node: The zsh/newuser Module,  Next: The zsh/parameter Module,  Prev: The zsh/nearcolor Module,  Up: Zsh Modules

21.21 The zsh/newuser Module
============================

The ‘zsh/newuser’ module is loaded at boot if it is available, the ‘RCS’
option is set, and the ‘PRIVILEGED’ option is not set (all three are
true by default).  This takes place immediately after commands in the
global ‘zshenv’ file (typically ‘/etc/zshenv’), if any, have been
executed.  If the module is not available it is silently ignored by the
shell; the module may safely be removed from ‘$MODULE_PATH’ by the
administrator if it is not required.

On loading, the module tests if any of the start-up files ‘.zshenv’,
‘.zprofile’, ‘.zshrc’ or ‘.zlogin’ exist in the directory given by the
environment variable ‘ZDOTDIR’, or the user’s home directory if that is
not set.  The test is not performed and the module halts processing if
the shell was in an emulation mode (i.e.  had been invoked as some other
shell than zsh).

If none of the start-up files were found, the module then looks for the
file ‘newuser’ first in a sitewide directory, usually the parent
directory of the ‘site-functions’ directory, and if that is not found
the module searches in a version-specific directory, usually the parent
of the ‘functions’ directory containing version-specific functions.
(These directories can be configured when zsh is built using the
‘--enable-site-scriptdir=’DIR and ‘--enable-scriptdir=’DIR flags to
‘configure’, respectively; the defaults are PREFIX‘/share/zsh’ and
PREFIX‘/share/zsh/$ZSH_VERSION’ where the default PREFIX is
‘/usr/local’.)

If the file ‘newuser’ is found, it is then sourced in the same manner as
a start-up file.  The file is expected to contain code to install
start-up files for the user, however any valid shell code will be
executed.

The ‘zsh/newuser’ module is then unconditionally unloaded.

Note that it is possible to achieve exactly the same effect as the
‘zsh/newuser’ module by adding code to ‘/etc/zshenv’.  The module exists
simply to allow the shell to make arrangements for new users without the
need for intervention by package maintainers and system administrators.

The script supplied with the module invokes the shell function
‘zsh-newuser-install’.  This may be invoked directly by the user even if
the ‘zsh/newuser’ module is disabled.  Note, however, that if the module
is not installed the function will not be installed either.  The
function is documented in *note User Configuration Functions: f.


File: zsh.info,  Node: The zsh/parameter Module,  Next: The zsh/pcre Module,  Prev: The zsh/newuser Module,  Up: Zsh Modules

21.22 The zsh/parameter Module
==============================

The ‘zsh/parameter’ module gives access to some of the internal hash
tables used by the shell by defining some special parameters.

‘options’

     The keys for this associative array are the names of the options
     that can be set and unset using the ‘setopt’ and ‘unsetopt’
     builtins.  The value of each key is either the string ‘on’ if the
     option is currently set, or the string ‘off’ if the option is
     unset.  Setting a key to one of these strings is like setting or
     unsetting the option, respectively.  Unsetting a key in this array
     is like setting it to the value ‘off’.

‘commands’

     This array gives access to the command hash table.  The keys are
     the names of external commands, the values are the pathnames of the
     files that would be executed when the command would be invoked.
     Setting a key in this array defines a new entry in this table in
     the same way as with the ‘hash’ builtin.  Unsetting a key as in
     ‘unset "commands[foo]"’ removes the entry for the given key from
     the command hash table.

‘functions’

     This associative array maps names of enabled functions to their
     definitions.  Setting a key in it is like defining a function with
     the name given by the key and the body given by the value.
     Unsetting a key removes the definition for the function named by
     the key.

‘dis_functions’

     Like ‘functions’ but for disabled functions.

‘functions_source’

     This readonly associative array maps names of enabled functions to
     the name of the file containing the source of the function.

     For an autoloaded function that has already been loaded, or marked
     for autoload with an absolute path, or that has had its path
     resolved with ‘functions -r’, this is the file found for
     autoloading, resolved to an absolute path.

     For a function defined within the body of a script or sourced file,
     this is the name of that file.  In this case, this is the exact
     path originally used to that file, which may be a relative path.

     For any other function, including any defined at an interactive
     prompt or an autoload function whose path has not yet been
     resolved, this is the empty string.  However, the hash element is
     reported as defined just so long as the function is present: the
     keys to this hash are the same as those to ‘$functions’.

‘dis_functions_source’

     Like ‘functions_source’ but for disabled functions.

‘builtins’

     This associative array gives information about the builtin commands
     currently enabled.  The keys are the names of the builtin commands
     and the values are either ‘undefined’ for builtin commands that
     will automatically be loaded from a module if invoked or ‘defined’
     for builtin commands that are already loaded.

‘dis_builtins’

     Like ‘builtins’ but for disabled builtin commands.

‘reswords’

     This array contains the enabled reserved words.

‘dis_reswords’

     Like ‘reswords’ but for disabled reserved words.

‘patchars’

     This array contains the enabled pattern characters.

‘dis_patchars’

     Like ‘patchars’ but for disabled pattern characters.

‘aliases’

     This maps the names of the regular aliases currently enabled to
     their expansions.

‘dis_aliases’

     Like ‘aliases’ but for disabled regular aliases.

‘galiases’

     Like ‘aliases’, but for global aliases.

‘dis_galiases’

     Like ‘galiases’ but for disabled global aliases.

‘saliases’

     Like ‘raliases’, but for suffix aliases.

‘dis_saliases’

     Like ‘saliases’ but for disabled suffix aliases.

‘parameters’

     The keys in this associative array are the names of the parameters
     currently defined.  The values are strings describing the type of
     the parameter, in the same format used by the ‘t’ parameter flag,
     see *note Parameter Expansion Flags: 6e.  The value may also be
     ‘undefined’ indicating a parameter that may be autoloaded from a
     module but has not yet been referenced.  When the key is the name
     of a named reference, the value is ‘nameref-’ prepended to the type
     of the referenced parameter, for example

           % typeset -n parms=parameters
           % print -r ${parameters[parms]}
           nameref-association-readonly-hide-hideval-special

     Setting or unsetting keys in this array is not possible.

‘modules’

     An associative array giving information about modules.  The keys
     are the names of the modules loaded, registered to be autoloaded,
     or aliased.  The value says which state the named module is in and
     is one of the strings ‘loaded’, ‘autoloaded’, or ‘alias:’NAME,
     where NAME is the name the module is aliased to.

     Setting or unsetting keys in this array is not possible.

‘dirstack’

     A normal array holding the elements of the directory stack.  Note
     that the output of the ‘dirs’ builtin command includes one more
     directory, the current working directory.

‘history’

     This associative array maps history event numbers to the full
     history lines.  Although it is presented as an associative array,
     the array of all values (‘${history[@]}’) is guaranteed to be
     returned in order from most recent to oldest history event, that
     is, by decreasing history event number.

‘historywords’

     A special array containing the words stored in the history.  These
     also appear in most to least recent order.

‘jobdirs’

     This associative array maps job numbers to the directories from
     which the job was started (which may not be the current directory
     of the job).

     The keys of the associative arrays are usually valid job numbers,
     and these are the values output with, for example, ‘${(k)jobdirs}’.
     Non-numeric job references may be used when looking up a value; for
     example, ‘${jobdirs[%+]}’ refers to the current job.

     See the ‘jobs’ builtin for how job information is provided in a
     subshell.

‘jobtexts’

     This associative array maps job numbers to the texts of the command
     lines that were used to start the jobs.

     Handling of the keys of the associative array is as described for
     ‘jobdirs’ above.

     See the ‘jobs’ builtin for how job information is provided in a
     subshell.

‘jobstates’

     This associative array gives information about the states of the
     jobs currently known.  The keys are the job numbers and the values
     are strings of the form JOB-STATE‘:’MARK‘:’PID‘=’STATE….  The
     JOB-STATE gives the state the whole job is currently in, one of
     ‘running’, ‘suspended’, or ‘done’.  The MARK is ‘+’ for the current
     job, ‘-’ for the previous job and empty otherwise.  This is
     followed by one ‘:’PID‘=’STATE for every process in the job.  The
     PIDs are, of course, the process IDs and the STATE describes the
     state of that process.

     Handling of the keys of the associative array is as described for
     ‘jobdirs’ above.

     See the ‘jobs’ builtin for how job information is provided in a
     subshell.

‘nameddirs’

     This associative array maps the names of named directories to the
     pathnames they stand for.

‘userdirs’

     This associative array maps user names to the pathnames of their
     home directories.

‘usergroups’

     This associative array maps names of system groups of which the
     current user is a member to the corresponding group identifiers.
     The contents are the same as the groups output by the ‘id’ command.

‘funcfiletrace’

     This array contains the absolute line numbers and corresponding
     file names for the point where the current function, sourced file,
     or (if ‘EVAL_LINENO’ is set) ‘eval’ command was called.  The array
     is of the same length as ‘funcsourcetrace’ and ‘functrace’, but
     differs from ‘funcsourcetrace’ in that the line and file are the
     point of call, not the point of definition, and differs from
     ‘functrace’ in that all values are absolute line numbers in files,
     rather than relative to the start of a function, if any.

‘funcsourcetrace’

     This array contains the file names and line numbers of the points
     where the functions, sourced files, and (if ‘EVAL_LINENO’ is set)
     ‘eval’ commands currently being executed were defined.  The line
     number is the line where the ‘function’ NAME or NAME ‘()’ started.
     In the case of an autoloaded function the line number is reported
     as zero.  The format of each element is FILENAME‘:’LINENO.

     For functions autoloaded from a file in native zsh format, where
     only the body of the function occurs in the file, or for files that
     have been executed by the ‘source’ or ‘.’ builtins, the trace
     information is shown as FILENAME‘:’0, since the entire file is the
     definition.  The source file name is resolved to an absolute path
     when the function is loaded or the path to it otherwise resolved.

     Most users will be interested in the information in the
     ‘funcfiletrace’ array instead.

‘funcstack’

     This array contains the names of the functions, sourced files, and
     (if ‘EVAL_LINENO’ is set) ‘eval’ commands.  currently being
     executed.  The first element is the name of the function using the
     parameter.

     The standard shell array ‘zsh_eval_context’ can be used to
     determine the type of shell construct being executed at each depth:
     note, however, that is in the opposite order, with the most recent
     item last, and it is more detailed, for example including an entry
     for ‘toplevel’, the main shell code being executed either
     interactively or from a script, which is not present in
     ‘$funcstack’.

‘functrace’

     This array contains the names and line numbers of the callers
     corresponding to the functions currently being executed.  The
     format of each element is NAME‘:’LINENO.  Callers are also shown
     for sourced files; the caller is the point where the ‘source’ or
     ‘.’ command was executed.


File: zsh.info,  Node: The zsh/pcre Module,  Next: The zsh/param/private Module,  Prev: The zsh/parameter Module,  Up: Zsh Modules

21.23 The zsh/pcre Module
=========================

The ‘zsh/pcre’ module makes some commands available as builtins:

‘pcre_compile’ [ ‘-aimxs’ ] PCRE

     Compiles a perl-compatible regular expression.

     Option ‘-a’ will force the pattern to be anchored.  Option ‘-i’
     will compile a case-insensitive pattern.  Option ‘-m’ will compile
     a multi-line pattern; that is, ‘^’ and ‘$’ will match newlines
     within the pattern.  Option ‘-x’ will compile an extended pattern,
     wherein whitespace and ‘#’ comments are ignored.  Option ‘-s’ makes
     the dot metacharacter match all characters, including those that
     indicate newline.

‘pcre_study’

     Requests JIT compilation for the previously-compiled PCRE which may
     result in faster matching.

‘pcre_match’ [ ‘-v’ VAR ] [ ‘-a’ ARR ] [ ‘-A’ ASSOC ] [ ‘-n’ OFFSET ] [
‘-bd’ ] STRING

     Returns successfully if ‘string’ matches the previously-compiled
     PCRE.

     Upon successful match, if the expression captures substrings within
     parentheses, ‘pcre_match’ will set the array ‘match’ to those
     substrings, unless the ‘-a’ option is given, in which case it will
     set the array ARR.  Similarly, the variable ‘MATCH’ will be set to
     the entire matched portion of the string, unless the ‘-v’ option is
     given, in which case the variable VAR will be set.  Furthermore,
     any named captures will be stored in the associative array
     ‘.pcre.match’ unless an alternative is given with ‘-A’.  No
     variables are altered if there is no successful match.  A ‘-n’
     option starts searching for a match from the byte OFFSET position
     in STRING.  If the ‘-b’ option is given, the variable ‘ZPCRE_OP’
     will be set to an offset pair string, representing the byte offset
     positions of the entire matched portion within the STRING.  For
     example, a ‘ZPCRE_OP’ set to “32 45” indicates that the matched
     portion began on byte offset 32 and ended on byte offset 44.  Here,
     byte offset position 45 is the position directly after the matched
     portion.  Keep in mind that the byte position isn’t necessarily the
     same as the character position when UTF-8 characters are involved.
     Consequently, the byte offset positions are only to be relied on in
     the context of using them for subsequent searches on STRING, using
     an offset position as an argument to the ‘-n’ option.  This is
     mostly used to implement the “find all non-overlapping matches”
     functionality.

     A simple example of “find all non-overlapping matches”:

           string="The following zip codes: 78884 90210 99513"
           pcre_compile -m "\d{5}"
           accum=()
           pcre_match -b -- $string
           while [[ $? -eq 0 ]] do
               b=($=ZPCRE_OP)
               accum+=$MATCH
               pcre_match -b -n $b[2] -- $string
           done
           print -l $accum

     The option ‘-d’ uses the alternative breadth-first DFA search
     algorithm of pcre.  This sets ‘match’, or the array given with
     ‘-a’, to all the matches found from the same start point in the
     subject.

     If the regular expression contains string callouts, these are
     executed as shell code, while numerical callouts are ignored.
     During the execution of the callout, the string the regular
     expression is matching against is available in the parameter
     ‘.pcre.subject’.  The parameter ‘.pcre.pos’ contains the position
     in that string that is currently being matched against.  If there
     is a non-zero return status from the shell code, the callout does
     not match.  Note that callouts are not available in the below
     -pcre-match test condition.  It is also likely not a good idea to
     call any pcre related builtins from a callout.  As an example, the
     following will print out ‘bar’:

           pcre_compile 'foo(?C"echo ${.pcre.subject[${.pcre.pos},-1]}")'
           pcre_match foobar

The ‘zsh/pcre’ module makes available the following test condition:

EXPR ‘-pcre-match’ PCRE

     Matches a string against a perl-compatible regular expression.

     For example,

           [[ "$text" -pcre-match ^d+$ ]] &&
           print text variable contains only "d's".

     If the ‘REMATCH_PCRE’ option is set, the ‘=~’ operator is
     equivalent to ‘-pcre-match’, and the ‘NO_CASE_MATCH’ option may be
     used.  Note that ‘NO_CASE_MATCH’ never applies to the ‘pcre_match’
     builtin, instead use the ‘-i’ switch of ‘pcre_compile’.


File: zsh.info,  Node: The zsh/param/private Module,  Next: The zsh/regex Module,  Prev: The zsh/pcre Module,  Up: Zsh Modules

21.24 The zsh/param/private Module
==================================

The ‘zsh/param/private’ module is used to create parameters whose scope
is limited to the current function body, and ‘not’ to other functions
called by the current function.

This module provides a single autoloaded builtin:

‘private’ [ {‘+|-}AHUahlmrtux’ ] [ {‘+|-}EFLRZi’ [ N ] ] [
NAME[‘=’VALUE] … ]

     The ‘private’ builtin accepts all the same options and arguments as
     ‘local’ (‘zshbuiltins’) except for the ‘-T’ option.  Tied
     parameters may not be made private.

     The ‘-p’ option is presently disabled because the state of private
     parameters cannot reliably be reloaded.  When ‘typeset -p’ outputs
     a private parameter, it is treated as a local with the ‘-h’ (hide)
     option enabled.

     If used at the top level (outside a function scope), ‘private’
     creates a normal parameter in the same manner as ‘declare’ or
     ‘typeset’.  A warning about this is printed if ‘WARN_CREATE_GLOBAL’
     is set (‘zshoptions’).  Used inside a function scope, ‘private’
     creates a local parameter similar to one declared with ‘local’,
     except having special properties noted below.

     Special parameters which expose or manipulate internal shell state,
     such as ‘ARGC’, ‘argv’, ‘COLUMNS’, ‘LINES’, ‘UID’, ‘EUID’, ‘IFS’,
     ‘PROMPT’, ‘RANDOM’, ‘SECONDS’, etc., cannot be made private unless
     the ‘-h’ option is used to hide the special meaning of the
     parameter.  This may change in the future.

As with other ‘typeset’ equivalents, ‘private’ is both a builtin and a
reserved word, so arrays may be assigned with parenthesized word list
NAME‘=(’VALUE…‘‘)‘‘ syntax.  However, the reserved word ‘private’ is not
available until ‘zsh/param/private’ is loaded, so care must be taken
with order of execution and parsing for function definitions which use
‘private’.  To compensate for this, the module also adds the option ‘-P’
to the ‘local’ builtin to declare private parameters.

For example, this construction fails if ‘zsh/param/private’ has not yet
been loaded when ‘bad_declaration’ is defined:

      bad_declaration() {
        zmodload zsh/param/private
        private array=( one two three )
      }

This construction works because ‘local’ is already a keyword, and the
module is loaded before the statement is executed:

      good_declaration() {
        zmodload zsh/param/private
        local -P array=( one two three )
      }

The following is usable in scripts but may have trouble with ‘autoload’:

      zmodload zsh/param/private
      iffy_declaration() {
        private array=( one two three )
      }

The ‘private’ builtin may always be used with scalar assignments and for
declarations without assignments.

Parameters declared with ‘private’ have the following properties:

        * Within the function body where it is declared, the parameter

     behaves as a local, except as noted above for tied or special
     parameters.  * The type of a parameter declared private cannot be
     changed in the scope where it was declared, even if the parameter
     is unset.  Thus an array cannot be assigned to a private scalar,
     etc.  * Within any other function called by the declaring function,
     the private parameter does ‘NOT’ hide other parameters of the same
     name, so for example a global parameter of the same name is visible
     and may be assigned or unset.  This includes calls to anonymous
     functions, although that may also change in the future.  However,
     the private name may not be created outside the local scope when it
     was not previously declared.  * An exported private remains in the
     environment of inner scopes but appears unset for the current shell
     in those scopes.  Generally, exporting private parameters should be
     avoided.  * Current shell command substitutions such as ‘${|...}’,
     ‘${|’VAR‘|...}’ and ‘${ ... }’ may read and assign private
     parameters from the enclosing function.  * Declaring a private
     parameter in a current shell command substitution limits that
     parameter to the scope of the command substitution, just as if the
     parameter were declared in a function.  This also prevents access
     by any enclosed current shell command substitutions, but other
     substitutions may use the private parameter because those have the
     same calling scope.

Note that this differs from the static scope defined by compiled
languages derived from C, in that a new call to the same function
creates a new scope, i.e., the parameter is still associated with the
call stack rather than with the function definition.  It differs from
ksh ‘typeset -S’ because the syntax used to define the function has no
bearing on whether the parameter scope is respected.


File: zsh.info,  Node: The zsh/regex Module,  Next: The zsh/random Module,  Prev: The zsh/param/private Module,  Up: Zsh Modules

21.25 The zsh/regex Module
==========================

The ‘zsh/regex’ module makes available the following test condition:

EXPR ‘-regex-match’ REGEX

     Matches a string against a POSIX extended regular expression.  On
     successful match, matched portion of the string will normally be
     placed in the ‘MATCH’ variable.  If there are any capturing
     parentheses within the regex, then the ‘match’ array variable will
     contain those.  If the match is not successful, then the variables
     will not be altered.

     For example,

           [[ alphabetical -regex-match ^a([^a]+)a([^a]+)a ]] &&
           print -l $MATCH X $match

     If the option ‘REMATCH_PCRE’ is not set, then the ‘=~’ operator
     will automatically load this module as needed and will invoke the
     ‘-regex-match’ operator.

     If ‘BASH_REMATCH’ is set, then the array ‘BASH_REMATCH’ will be set
     instead of ‘MATCH’ and ‘match’.

     Note that the ‘zsh/regex’ module logic relies on the host system.
     The same EXPR and REGEX pair could produce different results on
     different platforms if a REGEX with non-standard syntax is given.

     For example, no syntax for matching a word boundary is defined in
     the POSIX extended regular expression standard.  GNU ‘libc’ and BSD
     ‘libc’ both provide such syntaxes as extensions (‘\b’ and
     ‘[[:<:]]/[[:>:]]’ respectively), but neither of these syntaxes is
     supported by both of these implementations.

     Refer to the ‘regcomp(3)’ and ‘re_format(7)’ manual pages on your
     system for locally-supported syntax.


File: zsh.info,  Node: The zsh/random Module,  Next: The zsh/sched Module,  Prev: The zsh/regex Module,  Up: Zsh Modules

21.26 The zsh/random Module
===========================

The ‘zsh/random’ module gets random data from the kernel random pool.
If no kernel random pool can be found, the module will not load.

* Menu:

* Parameters: Parameters<3>.
* Math Functions::


File: zsh.info,  Node: Parameters<3>,  Next: Math Functions,  Up: The zsh/random Module

21.26.1 Parameters
------------------

‘SRANDOM’

     A random positive 32-bit integer between 0 and 4,294,967,295.  This
     parameter is read-only.  The name was chosen for compatibility with
     Bash and to distinguish it from ‘RANDOM’ which has a documented
     repeatable behavior.


File: zsh.info,  Node: Math Functions,  Prev: Parameters<3>,  Up: The zsh/random Module

21.26.2 Math Functions
----------------------

‘zrand_float()’

     Returns a random floating point number between 0 and 1 inclusive.

‘zrand_int’(UPPER, LOWER, INCLUSIVE)

     Returns a random integer between LOWER and UPPER.  All parameters
     are optional.  If none are specified it is equivalent to ‘SRANDOM’.
     Note that this is equivalent to passing the default values except
     that it is inclusive.

     UPPER is the upper bound on the resultant number and defaults to
     4,294,967,295.  It is exclusive by default, unless INCLUSIVE is
     passed.

     LOWER is the lower bound and defaults to 0.

     The defaults of these two arguments are also the maximum and
     minimum to which either can be set.

     INCLUSIVE is a flag that controls whether the UPPER bound is
     exclusive or inclusive.  Passing any non-zero value makes it
     inclusive, otherwise it is exclusive when the UPPER bound is
     specified.  The LOWER bound is always inclusive.

     This is to facilitate a construct like ‘$a[zrand_int($#a)+1]’
     rather than ‘$a[zrand_int($#a-1)+1]’.  For example, if $#a is 16,
     you would use ‘zrand_int(16)’ which has 16 possible return values
     0-15.  Because the function can return zero, in order to use it as
     an array index from 1-16 you need to add one.  It would be an array
     index range error for it to also potentially return 16 ($#a).  You
     could, however, use the construct ‘zrand_int(16,1,1)’ instead of
     adding 1 to achieve the same result, but it is more verbose.

     Most statistics algorithms seem to also expect 0 to UPPER-1, so
     this was deemed the most commonly desired case and chosen as the
     default.


File: zsh.info,  Node: The zsh/sched Module,  Next: The zsh/net/socket Module,  Prev: The zsh/random Module,  Up: Zsh Modules

21.27 The zsh/sched Module
==========================

The ‘zsh/sched’ module makes available one builtin command and one
parameter.

‘sched’ [‘-o’] [‘+’]:var:‘hh’‘:’MM[‘:’SS] COMMAND …

‘sched’ [‘-o’] [‘+’]:var:‘seconds’ COMMAND …

‘sched’ [ ‘-’ITEM ]

     Make an entry in the scheduled list of commands to execute.  The
     time may be specified in either absolute or relative time, and
     either as hours, minutes and (optionally) seconds separated by a
     colon, or seconds alone.  An absolute number of seconds indicates
     the time since the epoch (1970/01/01 00:00); this is useful in
     combination with the features in the ‘zsh/datetime’ module, see
     *note The zsh/datetime Module: 110.

     With no arguments, prints the list of scheduled commands.  If the
     scheduled command has the ‘-o’ flag set, this is shown at the start
     of the command.

     With the argument ‘-’ITEM, removes the given item from the list.
     The numbering of the list is continuous and entries are in time
     order, so the numbering can change when entries are added or
     deleted.

     Commands are executed either immediately before a prompt, or while
     the shell’s line editor is waiting for input.  In the latter case
     it is useful to be able to produce output that does not interfere
     with the line being edited.  Providing the option ‘-o’ causes the
     shell to clear the command line before the event and redraw it
     afterwards.  This should be used with any scheduled event that
     produces visible output to the terminal; it is not needed, for
     example, with output that updates a terminal emulator’s title bar.

     To effect changes to the editor buffer when an event executes, use
     the ‘zle’ command with no arguments to test whether the editor is
     active, and if it is, then use ‘zle’ WIDGET to access the editor
     via the named WIDGET.

     The ‘sched’ builtin is not made available by default when the shell
     starts in a mode emulating another shell.  It can be made available
     with the command ‘zmodload -F zsh/sched b:sched’.

‘zsh_scheduled_events’

     A readonly array corresponding to the events scheduled by the
     ‘sched’ builtin.  The indices of the array correspond to the
     numbers shown when ‘sched’ is run with no arguments (provided that
     the ‘KSH_ARRAYS’ option is not set).  The value of the array
     consists of the scheduled time in seconds since the epoch (see
     *note The zsh/datetime Module: 110. for facilities for using this
     number), followed by a colon, followed by any options (which may be
     empty but will be preceded by a ‘-’ otherwise), followed by a
     colon, followed by the command to be executed.

     The ‘sched’ builtin should be used for manipulating the events.
     Note that this will have an immediate effect on the contents of the
     array, so that indices may become invalid.


File: zsh.info,  Node: The zsh/net/socket Module,  Next: The zsh/stat Module,  Prev: The zsh/sched Module,  Up: Zsh Modules

21.28 The zsh/net/socket Module
===============================

The ‘zsh/net/socket’ module makes available one builtin command:

‘zsocket’ [ ‘-alstv’ ] [ ‘-d’ FD ] [ ARGS ]

     ‘zsocket’ is implemented as a builtin to allow full use of shell
     command line editing, file I/O, and job control mechanisms.

* Menu:

* Outbound Connections::
* Inbound Connections::


File: zsh.info,  Node: Outbound Connections,  Next: Inbound Connections,  Up: The zsh/net/socket Module

21.28.1 Outbound Connections
----------------------------

‘zsocket’ [ ‘-v’ ] [ ‘-d’ FD ] FILENAME

     Open a new Unix domain connection to FILENAME.  The shell parameter
     ‘REPLY’ will be set to the file descriptor associated with that
     connection.  Currently, only stream connections are supported.

     If ‘-d’ is specified, its argument will be taken as the target file
     descriptor for the connection.

     In order to elicit more verbose output, use ‘-v’.

     File descriptors can be closed with normal shell syntax when no
     longer needed, for example:

           exec {REPLY}>&-

     The ‘zsocket -s :var:`fd’‘ command may also be used to shut down a
     socket fd before closing it.  This will send an EOF to the other
     side, while this side can still read their subsequent response
     before closing the connection fully, for example.


File: zsh.info,  Node: Inbound Connections,  Prev: Outbound Connections,  Up: The zsh/net/socket Module

21.28.2 Inbound Connections
---------------------------

‘zsocket’ ‘-l’ [ ‘-v’ ] [ ‘-d’ FD ] FILENAME

     ‘zsocket -l’ will open a socket listening on FILENAME.  The shell
     parameter ‘REPLY’ will be set to the file descriptor associated
     with that listener.  The file descriptor remains open in subshells
     and forked external executables.

     If ‘-d’ is specified, its argument will be taken as the target file
     descriptor for the connection.

     In order to elicit more verbose output, use ‘-v’.

‘zsocket’ ‘-a’ [ ‘-tv’ ] [ ‘-d’ TARGETFD ] LISTENFD

     ‘zsocket -a’ will accept an incoming connection to the socket
     associated with LISTENFD.  The shell parameter ‘REPLY’ will be set
     to the file descriptor associated with the inbound connection.  The
     file descriptor remains open in subshells and forked external
     executables.

     If ‘-d’ is specified, its argument will be taken as the target file
     descriptor for the connection.

     If ‘-t’ is specified, ‘zsocket’ will return if no incoming
     connection is pending.  Otherwise it will wait for one.

     In order to elicit more verbose output, use ‘-v’.


File: zsh.info,  Node: The zsh/stat Module,  Next: The zsh/system Module,  Prev: The zsh/net/socket Module,  Up: Zsh Modules

21.29 The zsh/stat Module
=========================

The ‘zsh/stat’ module makes available one builtin command under two
possible names:

‘zstat’ [ ‘-gnNolLtTrs’ ] [ ‘-f’ FD ] [ ‘-H’ HASH ] [ ‘-A’ ARRAY ] [
‘-F’ FMT ]

     [ ‘+’ELEMENT ] [ FILE … ]

‘stat’ …

     The command acts as a front end to the ‘stat’ system call (see
     ‘stat(2)’).  The same command is provided with two names; as the
     name ‘stat’ is often used by an external command it is recommended
     that only the ‘zstat’ form of the command is used.  This can be
     arranged by loading the module with the command ‘zmodload -F
     zsh/stat b:zstat’.

     If the ‘stat’ call fails, the appropriate system error message
     printed and status 1 is returned.  The fields of ‘struct stat’ give
     information about the files provided as arguments to the command.
     In addition to those available from the ‘stat’ call, an extra
     element ‘link’ is provided.  These elements are:

     ‘device’

          The number of the device on which the file resides.

     ‘inode’

          The unique number of the file on this device (‘inode’ number).

     ‘mode’

          The mode of the file; that is, the file’s type and access
          permissions.  With the ‘-s’ option, this will be returned as a
          string corresponding to the first column in the display of the
          ‘ls -l’ command.

     ‘nlink’

          The number of hard links to the file.

     ‘uid’

          The user ID of the owner of the file.  With the ‘-s’ option,
          this is displayed as a user name.

     ‘gid’

          The group ID of the file.  With the ‘-s’ option, this is
          displayed as a group name.

     ‘rdev’

          The raw device number.  This is only useful for special
          devices.

     ‘size’

          The size of the file in bytes.

     ‘atime’

     ‘mtime’

     ‘ctime’

          The last access, modification and inode change times of the
          file, respectively, as the number of seconds since midnight
          GMT on 1st January, 1970.  With the ‘-s’ option, these are
          printed as strings for the local time zone; the format can be
          altered with the ‘-F’ option, and with the ‘-g’ option the
          times are in GMT.

     ‘blksize’

          The number of bytes in one allocation block on the device on
          which the file resides.

     ‘block’

          The number of disk blocks used by the file.

     ‘link’

          If the file is a link and the ‘-L’ option is in effect, this
          contains the name of the file linked to, otherwise it is
          empty.  Note that if this element is selected (‘`zstat
          +link’’) then the ‘-L’ option is automatically used.

     A particular element may be selected by including its name preceded
     by a ‘+’ in the option list; only one element is allowed.  The
     element may be shortened to any unique set of leading characters.
     Otherwise, all elements will be shown for all files.

     Options:

     ‘-A’ ARRAY

          Instead of displaying the results on standard output, assign
          them to an ARRAY, one ‘struct stat’ element per array element
          for each file in order.  In this case neither the name of the
          element nor the name of the files appears in ARRAY unless the
          ‘-t’ or ‘-n’ options were given, respectively.  If ‘-t’ is
          given, the element name appears as a prefix to the appropriate
          array element; if ‘-n’ is given, the file name appears as a
          separate array element preceding all the others.  Other
          formatting options are respected.

     ‘-H’ HASH

          Similar to ‘-A’, but instead assign the values to HASH.  The
          keys are the elements listed above.  If the ‘-n’ option is
          provided then the name of the file is included in the hash
          with key ‘name’.

     ‘-f’ FD

          Use the file on file descriptor FD instead of named files; no
          list of file names is allowed in this case.

     ‘-F’ FMT

          Supplies a ‘strftime’ (see ‘strftime(3)’) string for the
          formatting of the time elements.  The format string supports
          all of the zsh extensions (see the description of
          ‘%D{’STRING‘}’ prompt escape in *note Simple Prompt Escapes:
          131.).  In particular, ‘-F %s.%N’ can be used to show
          timestamps with nanosecond precision if supported by the
          system.  The ‘-s’ option is implied.

     ‘-g’

          Show the time elements in the GMT time zone.  The ‘-s’ option
          is implied.

     ‘-l’

          List the names of the type elements (to standard output or an
          array as appropriate) and return immediately; arguments, and
          options other than ‘-A’, are ignored.

     ‘-L’

          Perform an ‘lstat’ (see ‘lstat(2)’) rather than a ‘stat’
          system call.  In this case, if the file is a link, information
          about the link itself rather than the target file is returned.
          This option is required to make the ‘link’ element useful.
          It’s important to note that this is the exact opposite from
          ‘ls(1)’, etc.

     ‘-n’

          Always show the names of files.  Usually these are only shown
          when output is to standard output and there is more than one
          file in the list.

     ‘-N’

          Never show the names of files.

     ‘-o’

          If a raw file mode is printed, show it in octal, which is more
          useful for human consumption than the default of decimal.  A
          leading zero will be printed in this case.  Note that this
          does not affect whether a raw or formatted file mode is shown,
          which is controlled by the ‘-r’ and ‘-s’ options, nor whether
          a mode is shown at all.

     ‘-r’

          Print raw data (the default format) alongside string data (the
          ‘-s’ format); the string data appears in parentheses after the
          raw data.

     ‘-s’

          Print ‘mode’, ‘uid’, ‘gid’ and the three time elements as
          strings instead of numbers.  In each case the format is like
          that of ‘ls -l’.

     ‘-t’

          Always show the type names for the elements of ‘struct stat’.
          Usually these are only shown when output is to standard output
          and no individual element has been selected.

     ‘-T’

          Never show the type names of the ‘struct stat’ elements.


File: zsh.info,  Node: The zsh/system Module,  Next: The zsh/net/tcp Module,  Prev: The zsh/stat Module,  Up: Zsh Modules

21.30 The zsh/system Module
===========================

The ‘zsh/system’ module makes available various builtin commands and
parameters.

* Menu:

* Builtins::
* Math Functions: Math Functions<2>.
* Parameters: Parameters<4>.


File: zsh.info,  Node: Builtins,  Next: Math Functions<2>,  Up: The zsh/system Module

21.30.1 Builtins
----------------

‘syserror’ [ ‘-e’ ERRVAR ] [ ‘-p’ PREFIX ] [ ERRNO | ERRNAME ]

     This command prints out the error message associated with ERRNO, a
     system error number, followed by a newline to standard error.

     Instead of the error number, a name ERRNAME, for example ‘ENOENT’,
     may be used.  The set of names is the same as the contents of the
     array ‘errnos’, see below.

     If the string PREFIX is given, it is printed in front of the error
     message, with no intervening space.

     If ERRVAR is supplied, the entire message, without a newline, is
     assigned to the parameter names ERRVAR and nothing is output.

     A return status of 0 indicates the message was successfully printed
     (although it may not be useful if the error number was out of the
     system’s range), a return status of 1 indicates an error in the
     parameters, and a return status of 2 indicates the error name was
     not recognised (no message is printed for this).

‘sysopen’ [ ‘-arw’ ] [ ‘-m’ PERMISSIONS ] [ ‘-o’ OPTIONS ]

          ‘-u’ FD FILE

     This command opens a file.  The ‘-r’, ‘-w’ and ‘-a’ flags indicate
     whether the file should be opened for reading, writing and
     appending, respectively.  The ‘-m’ option allows the initial
     permissions to use when creating a file to be specified in octal
     form.  The file descriptor is specified with ‘-u’.  Either an
     explicit file descriptor in the range 0 to 9 can be specified or a
     variable name can be given to which the file descriptor number will
     be assigned.

     The ‘-o’ option allows various system specific options to be
     specified as a comma-separated list.  The following is a list of
     possible options.  Note that, depending on the system, some may not
     be available.

     ‘cloexec’

          mark file to be closed when other programs are executed (else
          the file descriptor remains open in subshells and forked
          external executables)

     ‘create’

     ‘creat’

          create file if it does not exist

     ‘excl’

          create file, error if it already exists

     ‘noatime’

          suppress updating of the file atime

     ‘nofollow’

          fail if FILE is a symbolic link

     ‘nonblock’

          the file is opened in nonblocking mode

     ‘sync’

          request that writes wait until data has been physically
          written

     ‘truncate’

     ‘trunc’

          truncate file to size 0

     A return status of 0 indicates the descriptor was successfully
     opened, otherwise an error message is printed, and 1 is returned
     for an error in the parameters to the command, or 2 is returned for
     a system error.  The parameter ‘ERRNO’ is nonzero for system
     errors.

     To close the file, use one of the following:

           exec {FD}<&-
           exec {FD}>&-

‘sysread’ [ ‘-c’ COUNTVAR ] [ ‘-i’ INFD ] [ ‘-o’ OUTFD ]

          [ ‘-s’ BUFSIZE ] [ ‘-t’ TIMEOUT ] [ PARAM ]

     Perform a single system read from file descriptor INFD, or zero if
     that is not given.  The result of the read is stored in PARAM or
     ‘REPLY’ if that is not given.  If COUNTVAR is given, the number of
     bytes read is assigned to the parameter named by COUNTVAR.

     The maximum number of bytes read is BUFSIZE or 8192 if that is not
     given, however the command returns as soon as any number of bytes
     was successfully read.

     If TIMEOUT is given, it specifies a timeout in seconds, which may
     be zero to poll the file descriptor.  This is handled by the ‘poll’
     system call if available, otherwise the ‘select’ system call if
     available.

     If OUTFD is given, an attempt is made to write all the bytes just
     read to the file descriptor OUTFD.  If this fails, because of a
     system error other than ‘EINTR’ or because of an internal zsh error
     during an interrupt, the bytes read but not written are stored in
     the parameter named by PARAM if supplied (no default is used in
     this case), and the number of bytes read but not written is stored
     in the parameter named by COUNTVAR if that is supplied.  If it was
     successful, COUNTVAR contains the full number of bytes transferred,
     as usual, and PARAM is not set.

     The error ‘EINTR’ (interrupted system call) is handled internally
     so that shell interrupts are transparent to the caller.  Any other
     error causes a return.

     The possible return statuses are

     0

          At least one byte of data was successfully read and, if
          appropriate, written.

     1

          There was an error in the parameters to the command.  This is
          the only error for which a message is printed to standard
          error.

     2

          There was an error on the read, or on polling the input file
          descriptor for a timeout.  The parameter ‘ERRNO’ identifies
          the error.

     3

          Data were successfully read, but there was an error writing
          them to OUTFD.  The parameter ‘ERRNO’ identifies the error.

     4

          The attempt to read timed out.  Note this does not set ‘ERRNO’
          as this is not a system error.

     5

          No system error occurred, but zero bytes were read.  This
          usually indicates end of file.  The parameters are set
          according to the usual rules; no write to OUTFD is attempted.

‘sysseek’ [ ‘-u’ FD ] [ ‘-w’ ‘start|end|current’ ] OFFSET

     The current file position at which future reads and writes will
     take place is adjusted to the specified byte offset.  The OFFSET is
     evaluated as a math expression.  The ‘-u’ option allows the file
     descriptor to be specified.  By default the offset is specified
     relative to the start or the file but, with the ‘-w’ option, it is
     possible to specify that the offset should be relative to the
     current position or the end of the file.

     The return status may be 0 for success, 1 for an error in the
     parameters to the command, or 2 for an error on the seek; no error
     message is printed in the last case, but the parameter ‘ERRNO’
     reflects the error that occurred.

‘syswrite’ [ ‘-c’ COUNTVAR ] [ ‘-o’ OUTFD ] DATA

     The data (a single string of bytes) are written to the file
     descriptor OUTFD, or 1 if that is not given, using the ‘write’
     system call.  Multiple write operations may be used if the first
     does not write all the data.

     If COUNTVAR is given, the number of byte written is stored in the
     parameter named by COUNTVAR; this may not be the full length of
     DATA if an error occurred.

     The error ‘EINTR’ (interrupted system call) is handled internally
     by retrying; otherwise an error causes the command to return.  For
     example, if the file descriptor is set to non-blocking output, an
     error ‘EAGAIN’ (on some systems, ‘EWOULDBLOCK’) may result in the
     command returning early.

     The return status may be 0 for success, 1 for an error in the
     parameters to the command, or 2 for an error on the write; no error
     message is printed in the last case, but the parameter ‘ERRNO’
     reflects the error that occurred.

‘zsystem flock’ [ ‘-t’ TIMEOUT ] [ ‘-i’ INTERVAL ] [ ‘-f’ VAR ] [‘-er’]
FILE

‘zsystem flock -u’ FD_EXPR

     The builtin ‘zsystem’’s subcommand ‘flock’ performs advisory file
     locking (via the ‘fcntl(2)’ system call) over the entire contents
     of the given file.  This form of locking requires the processes
     accessing the file to cooperate; its most obvious use is between
     two instances of the shell itself.

     In the first form the named FILE, which must already exist, is
     locked by opening a file descriptor to the file and applying a lock
     to the file descriptor.  The lock terminates when the shell process
     that created the lock exits; it is therefore often convenient to
     create file locks within subshells, since the lock is automatically
     released when the subshell exits.  Note that use of the ‘print’
     builtin with the ‘-u’ option will, as a side effect, release the
     lock, as will redirection to the file in the shell holding the
     lock.  To work around this use a subshell, e.g.  ‘(print message)
     >>’ FILE.  Status 0 is returned if the lock succeeds, else status
     1.

     In the second form the file descriptor given by the arithmetic
     expression FD_EXPR is closed, releasing a lock.  The file
     descriptor can be queried by using the ‘-f’ VAR form during the
     lock; on a successful lock, the shell variable VAR is set to the
     file descriptor used for locking.  The lock will be released if the
     file descriptor is closed by any other means, for example using
     ‘exec {’VAR‘}>&-’; however, the form described here performs a
     safety check that the file descriptor is in use for file locking.

     By default the shell waits indefinitely for the lock to succeed.
     The option ‘-t’ TIMEOUT specifies a timeout for the lock in
     seconds; fractional seconds are allowed.  During this period, the
     shell will attempt to lock the file every INTERVAL seconds if the
     ‘-i’ INTERVAL option is given, otherwise once a second.  (This
     INTERVAL is shortened before the last attempt if needed, so that
     the shell waits only until the TIMEOUT and not longer.)  If the
     attempt times out, status 2 is returned.

     (Note: TIMEOUT is limited to 2^30-1 seconds (about 34 years), and
     INTERVAL to 0.999 * LONG_MAX microseconds (only about 35 minutes on
     32-bit systems).)

     If the option ‘-e’ is given, the file descriptor for the lock is
     preserved when the shell uses ‘exec’ to start a new process;
     otherwise it is closed at that point and the lock released.

     If the option ‘-r’ is given, the lock is only for reading,
     otherwise it is for reading and writing.  The file descriptor is
     opened accordingly.

‘zsystem supports’ SUBCOMMAND

     The builtin ‘zsystem’’s subcommand ‘supports’ tests whether a given
     subcommand is supported.  It returns status 0 if so, else status 1.
     It operates silently unless there was a syntax error (i.e.  the
     wrong number of arguments), in which case status 255 is returned.
     Status 1 can indicate one of two things: SUBCOMMAND is known but
     not supported by the current operating system, or SUBCOMMAND is not
     known (possibly because this is an older version of the shell
     before it was implemented).


File: zsh.info,  Node: Math Functions<2>,  Next: Parameters<4>,  Prev: Builtins,  Up: The zsh/system Module

21.30.2 Math Functions
----------------------

‘systell(:var:`fd`)’

     The systell math function returns the current file position for the
     file descriptor passed as an argument.


File: zsh.info,  Node: Parameters<4>,  Prev: Math Functions<2>,  Up: The zsh/system Module

21.30.3 Parameters
------------------

‘errnos’

     A readonly array of the names of errors defined on the system.
     These are typically macros defined in C by including the system
     header file ‘errno.h’.  The index of each name (assuming the option
     ‘KSH_ARRAYS’ is unset) corresponds to the error number.  Error
     numbers NUM before the last known error which have no name are
     given the name ‘E’NUM in the array.

     Note that aliases for errors are not handled; only the canonical
     name is used.

‘sysparams’

     A readonly associative array.  The keys are:

     ‘pid’

          Returns the process ID of the current process, even in
          subshells.  Compare ‘$$’, which returns the process ID of the
          main shell process.

     ‘ppid’

          Returns the current process ID of the parent of the current
          process, even in subshells.  Compare ‘$PPID’, which returns
          the process ID of the initial parent of the main shell
          process.

     ‘procsubstpid’

          Returns the process ID of the last process started for process
          substitution, i.e.  the ‘<(’…‘)’ and ‘>(’…‘)’ expansions.


File: zsh.info,  Node: The zsh/net/tcp Module,  Next: The zsh/termcap Module,  Prev: The zsh/system Module,  Up: Zsh Modules

21.31 The zsh/net/tcp Module
============================

The ‘zsh/net/tcp’ module makes available one builtin command:

‘ztcp’ [ ‘-acflLstv’ ] [ ‘-d’ FD ] [ ARGS ]

     ‘ztcp’ is implemented as a builtin to allow full use of shell
     command line editing, file I/O, and job control mechanisms.

     If ‘ztcp’ is run with no options, it will output the contents of
     its session table.

     If it is run with only the option ‘-L’, it will output the contents
     of the session table in a format suitable for automatic parsing.
     The option is ignored if given with a command to open or close a
     session.  The output consists of a set of lines, one per session,
     each containing the following elements separated by spaces:

     File descriptor

          The file descriptor in use for the connection.  For normal
          inbound (‘I’) and outbound (‘O’) connections this may be read
          and written by the usual shell mechanisms.  However, it should
          only be closed with ‘ztcp -c’.

     Connection type

          A letter indicating how the session was created:

          ‘Z’

               A session created with the ‘zftp’ command.

          ‘L’

               A connection opened for listening with ‘ztcp -l’.

          ‘I’

               An inbound connection accepted with ‘ztcp -a’.

          ‘O’

               An outbound connection created with ‘ztcp’ HOST ….

          ‘S’

               A connection that has been shut down with ‘ztcp -s’.

     The local host

          This is usually set to an all-zero IP address as the address
          of the localhost is irrelevant.

     The local port

          This is likely to be zero unless the connection is for
          listening.

     The remote host

          This is the fully qualified domain name of the peer, if
          available, else an IP address.  It is an all-zero IP address
          for a session opened for listening.

     The remote port

          This is zero for a connection opened for listening.

* Menu:

* Outbound Connections: Outbound Connections<2>.
* Inbound Connections: Inbound Connections<2>.
* Closing Connections::
* Example: Example<2>.


File: zsh.info,  Node: Outbound Connections<2>,  Next: Inbound Connections<2>,  Up: The zsh/net/tcp Module

21.31.1 Outbound Connections
----------------------------

‘ztcp’ [ ‘-v’ ] [ ‘-d’ FD ] HOST [ PORT ]

     Open a new TCP connection to HOST.  If the PORT is omitted, it will
     default to port 23.  The connection will be added to the session
     table and the shell parameter ‘REPLY’ will be set to the file
     descriptor associated with that connection.

     If ‘-d’ is specified, its argument will be taken as the target file
     descriptor for the connection.

     In order to elicit more verbose output, use ‘-v’.


File: zsh.info,  Node: Inbound Connections<2>,  Next: Closing Connections,  Prev: Outbound Connections<2>,  Up: The zsh/net/tcp Module

21.31.2 Inbound Connections
---------------------------

‘ztcp’ ‘-l’ [ ‘-v’ ] [ ‘-d’ FD ] PORT

     ‘ztcp -l’ will open a socket listening on TCP PORT.  The socket
     will be added to the session table and the shell parameter ‘REPLY’
     will be set to the file descriptor associated with that listener.

     If ‘-d’ is specified, its argument will be taken as the target file
     descriptor for the connection.

     In order to elicit more verbose output, use ‘-v’.

‘ztcp’ ‘-a’ [ ‘-tv’ ] [ ‘-d’ TARGETFD ] LISTENFD

     ‘ztcp -a’ will accept an incoming connection to the port associated
     with LISTENFD.  The connection will be added to the session table
     and the shell parameter ‘REPLY’ will be set to the file descriptor
     associated with the inbound connection.

     If ‘-d’ is specified, its argument will be taken as the target file
     descriptor for the connection.

     If ‘-t’ is specified, ‘ztcp’ will return if no incoming connection
     is pending.  Otherwise it will wait for one.

     In order to elicit more verbose output, use ‘-v’.


File: zsh.info,  Node: Closing Connections,  Next: Example<2>,  Prev: Inbound Connections<2>,  Up: The zsh/net/tcp Module

21.31.3 Closing Connections
---------------------------

‘ztcp’ ‘-s’ FD

     ‘ztcp -s’ will shut down the socket associated with FD.  This means
     a graceful termination of the connection is initiated, flushing
     unsent data (due to Nagle’s algorithm, for example).  To complete
     it, you should also drain any remaining data on the fd by reading
     it.  Afterwards you should use ‘ztcp -c’ to close the fd.  If you
     close it without first using ‘ztcp -s’ and draining the data, the
     kernel may reset the connection, causing data you sent to not be
     received by the other end.

     Note that this is only useful for inbound and outbound connections,
     not for listening sockets.

‘ztcp’ ‘-cf’ [ ‘-v’ ] [ FD ]

‘ztcp’ ‘-c’ [ ‘-v’ ] [ FD ]

     ‘ztcp -c’ will close the socket associated with FD.  The socket
     will be removed from the session table.  If FD is not specified,
     ‘ztcp’ will close everything in the session table.

     See also the previous ‘ztcp -s’ entry.

     Normally, sockets registered by zftp (see *note The zsh/zftp
     Module: cb.) cannot be closed this way.  In order to force such a
     socket closed, use ‘-f’.

     In order to elicit more verbose output, use ‘-v’.


File: zsh.info,  Node: Example<2>,  Prev: Closing Connections,  Up: The zsh/net/tcp Module

21.31.4 Example
---------------

Here is how to create a TCP connection between two instances of zsh.  We
need to pick an unassigned port; here we use the randomly chosen 5123.

On ‘host1’,

      zmodload zsh/net/tcp
      ztcp -l 5123
      listenfd=$REPLY
      ztcp -a $listenfd
      fd=$REPLY

The second from last command blocks until there is an incoming
connection.

Now create a connection from ‘host2’ (which may, of course, be the same
machine):

      zmodload zsh/net/tcp
      ztcp host1 5123
      fd=$REPLY

Now on each host, ‘$fd’ contains a file descriptor for talking to the
other.  For example, on ‘host1’:

      print This is a message >&$fd

and on ‘host2’:

      read -r line <&$fd; print -r - $line

prints ‘This is a message’.

To tidy up, on ‘host1’:

      ztcp -c $listenfd
      ztcp -s $fd
      ztcp -c $fd

and on ‘host2’

      ztcp -s $fd
      ztcp -c $fd


File: zsh.info,  Node: The zsh/termcap Module,  Next: The zsh/terminfo Module,  Prev: The zsh/net/tcp Module,  Up: Zsh Modules

21.32 The zsh/termcap Module
============================

The ‘zsh/termcap’ module makes available one builtin command:

‘echotc’ CAP [ ARG … ]

     Output the termcap value corresponding to the capability CAP, with
     optional arguments.

The ‘zsh/termcap’ module makes available one parameter:

‘termcap’

     An associative array that maps termcap capability codes to their
     values.


File: zsh.info,  Node: The zsh/terminfo Module,  Next: The zsh/watch Module,  Prev: The zsh/termcap Module,  Up: Zsh Modules

21.33 The zsh/terminfo Module
=============================

The ‘zsh/terminfo’ module makes available one builtin command:

‘echoti’ CAP [ ARG ]

     Output the terminfo value corresponding to the capability CAP,
     instantiated with ARG if applicable.

The ‘zsh/terminfo’ module makes available one parameter:

‘terminfo’

     An associative array that maps terminfo capability names to their
     values.


File: zsh.info,  Node: The zsh/watch Module,  Next: The zsh/zftp Module,  Prev: The zsh/terminfo Module,  Up: Zsh Modules

21.34 The zsh/watch Module
==========================

The ‘zsh/watch’ module can be used to report when specific users log in
or out.  This is controlled via the following parameters.

‘LOGCHECK’

     The interval in seconds between checks for login/logout activity
     using the ‘watch’ parameter.

‘watch’ <S> <Z> (‘WATCH’ <S>)

     An array (colon-separated list) of login/logout events to report.

     If it contains the single word ‘all’, then all login/logout events
     are reported.  If it contains the single word ‘notme’, then all
     events are reported as with ‘all’ except ‘$USERNAME’.

     An entry in this list may consist of a username, an ‘@’ followed by
     a remote hostname, and a ‘%’ followed by a line (tty).  Any of
     these may be a pattern (be sure to quote this during the assignment
     to ‘watch’ so that it does not immediately perform file
     generation); the setting of the ‘EXTENDED_GLOB’ option is
     respected.  Any or all of these components may be present in an
     entry; if a login/logout event matches all of them, it is reported.

     For example, with the ‘EXTENDED_GLOB’ option set, the following:

           watch=('^(pws|barts)')

     causes reports for activity associated with any user other than
     ‘pws’ or ‘barts’.

‘WATCHFMT’

     The format of login/logout reports if the ‘watch’ parameter is set.
     Default is ‘%n has %a %l from %m’.  Recognizes the following escape
     sequences, many of which are described further in *note Simple
     Prompt Escapes: 131.:

     ‘%n’

          The name of the user that logged in/out.

     ‘%a’

          The observed action, i.e.  “logged on” or “logged off”.

     ‘%l’

          The line (tty) the user is logged in on.

     ‘%M’

          The full hostname of the remote host.

     ‘%m’

          The hostname up to the first ‘.’.  If only the IP address is
          available or the utmp field contains the name of an X-windows
          display, the whole name is printed.

          ‘NOTE:’ The ‘%m’ and ‘%M’ escapes will work only if there is a
          host name field in the utmp on your machine.  Otherwise they
          are treated as ordinary strings.

     ‘%F{’COLOR‘}’ (‘%f’)

          Start (stop) using a different foreground color.

     ‘%K{’COLOR‘}’ (‘%k’)

          Start (stop) using a different background color.

     ‘%H{’GROUP‘}’

          Change all character visual attributes using a highlighting
          specification from the ‘.zle.hlgroups’ associative array.

     ‘%S’ (‘%s’)

          Start (stop) standout mode.

     ‘%U’ (‘%u’)

          Start (stop) underline mode.

     ‘%B’ (‘%b’)

          Start (stop) boldface mode.

     ‘%t’

     ‘%@’

          The time, in 12-hour, am/pm format.

     ‘%T’

          The time, in 24-hour format.

     ‘%w’

          The date in DAY‘-’DD format.

     ‘%W’

          The date in MM‘/’DD‘/’YY format.

     ‘%D’

          The date in YY‘-’MM‘-’DD format.

     ‘%D{’STRING‘}’

          The date formatted as STRING using the ‘strftime’ function,
          with zsh extensions as described for ‘%D{’STRING‘}’ escape
          sequence in *note Simple Prompt Escapes: 131.

     ‘%(’X‘:’TRUE-TEXT‘:’FALSE-TEXT‘)’

          Specifies a ternary expression.  The character following the X
          is arbitrary; the same character is used to separate the text
          for the “true” result from that for the “false” result.  Both
          the separator and the right parenthesis may be escaped with a
          backslash.  Ternary expressions may be nested.

          The test character X may be any one of ‘l’, ‘n’, ‘m’ or ‘M’,
          which indicate a ‘true’ result if the corresponding escape
          sequence would return a non-empty value; or it may be ‘a’,
          which indicates a ‘true’ result if the watched user has logged
          in, or ‘false’ if he has logged out.  Other characters
          evaluate to neither true nor false; the entire expression is
          omitted in this case.

          If the result is ‘true’, then the TRUE-TEXT is formatted
          according to the rules above and printed, and the FALSE-TEXT
          is skipped.  If ‘false’, the TRUE-TEXT is skipped and the
          FALSE-TEXT is formatted and printed.  Either or both of the
          branches may be empty, but both separators must be present in
          any case.

Furthermore, the ‘zsh/watch’ module makes available one builtin command:

‘log’

     List all users currently logged in who are affected by the current
     setting of the ‘watch’ parameter.


File: zsh.info,  Node: The zsh/zftp Module,  Next: The zsh/zle Module,  Prev: The zsh/watch Module,  Up: Zsh Modules

21.35 The zsh/zftp Module
=========================

The ‘zsh/zftp’ module makes available one builtin command:

‘zftp’ SUBCOMMAND [ ARGS ]

     The ‘zsh/zftp’ module is a client for FTP (file transfer protocol).
     It is implemented as a builtin to allow full use of shell command
     line editing, file I/O, and job control mechanisms.  Often, users
     will access it via shell functions providing a more powerful
     interface; a set is provided with the ‘zsh’ distribution and is
     described in ‘zshzftpsys’.  However, the ‘zftp’ command is entirely
     usable in its own right.

     All commands consist of the command name ‘zftp’ followed by the
     name of a subcommand.  These are listed below.  The return status
     of each subcommand is supposed to reflect the success or failure of
     the remote operation.  See a description of the variable
     ‘ZFTP_VERBOSE’ for more information on how responses from the
     server may be printed.

* Menu:

* Subcommands::
* Parameters: Parameters<5>.
* Functions: Functions<3>.
* Problems::


File: zsh.info,  Node: Subcommands,  Next: Parameters<5>,  Up: The zsh/zftp Module

21.35.1 Subcommands
-------------------

‘open’ HOST[‘:’PORT] [ USER [ PASSWORD [ ACCOUNT ] ] ]

     Open a new FTP session to HOST, which may be the name of a TCP/IP
     connected host or an IP number in the standard dot notation.  If
     the argument is in the form HOST‘:’PORT, open a connection to TCP
     port PORT instead of the standard FTP port 21.  This may be the
     name of a TCP service or a number: see the description of
     ‘ZFTP_PORT’ below for more information.

     If IPv6 addresses in colon format are used, the HOST should be
     surrounded by quoted square brackets to distinguish it from the
     PORT, for example ‘'[fe80::203:baff:fe02:8b56]'’.  For consistency
     this is allowed with all forms of HOST.

     Remaining arguments are passed to the ‘login’ subcommand.  Note
     that if no arguments beyond HOST are supplied, ‘open’ will ‘not’
     automatically call ‘login’.  If no arguments at all are supplied,
     ‘open’ will use the parameters set by the ‘params’ subcommand.

     After a successful open, the shell variables ‘ZFTP_HOST’,
     ‘ZFTP_PORT’, ‘ZFTP_IP’ and ‘ZFTP_SYSTEM’ are available; see
     ‘Variables’ below.

‘login’ [ NAME [ PASSWORD [ ACCOUNT ] ] ]

‘user’ [ NAME [ PASSWORD [ ACCOUNT ] ] ]

     Login the user NAME with parameters PASSWORD and ACCOUNT.  Any of
     the parameters can be omitted, and will be read from standard input
     if needed (NAME is always needed).  If standard input is a
     terminal, a prompt for each one will be printed on standard error
     and PASSWORD will not be echoed.  If any of the parameters are not
     used, a warning message is printed.

     After a successful login, the shell variables ‘ZFTP_USER’,
     ‘ZFTP_ACCOUNT’ and ‘ZFTP_PWD’ are available; see ‘Variables’ below.

     This command may be re-issued when a user is already logged in, and
     the server will first be reinitialized for a new user.

‘params’ [ HOST [ USER [ PASSWORD [ ACCOUNT ] ] ] ]

‘params’ ‘-’

     Store the given parameters for a later ‘open’ command with no
     arguments.  Only those given on the command line will be
     remembered.  If no arguments are given, the parameters currently
     set are printed, although the password will appear as a line of
     stars; the return status is one if no parameters were set, zero
     otherwise.

     Any of the parameters may be specified as a ‘?’, which may need to
     be quoted to protect it from shell expansion.  In this case, the
     appropriate parameter will be read from stdin as with the ‘login’
     subcommand, including special handling of PASSWORD.  If the ‘?’ is
     followed by a string, that is used as the prompt for reading the
     parameter instead of the default message (any necessary punctuation
     and whitespace should be included at the end of the prompt).  The
     first letter of the parameter (only) may be quoted with a ‘\’;
     hence an argument ‘"\\$word"’ guarantees that the string from the
     shell parameter ‘$word’ will be treated literally, whether or not
     it begins with a ‘?’.

     If instead a single ‘-’ is given, the existing parameters, if any,
     are deleted.  In that case, calling ‘open’ with no arguments will
     cause an error.

     The list of parameters is not deleted after a ‘close’, however it
     will be deleted if the ‘zsh/zftp’ module is unloaded.

     For example,

           zftp params ftp.elsewhere.xx juser '?Password for juser: '

     will store the host ‘ftp.elsewhere.xx’ and the user ‘juser’ and
     then prompt the user for the corresponding password with the given
     prompt.

‘test’

     Test the connection; if the server has reported that it has closed
     the connection (maybe due to a timeout), return status 2; if no
     connection was open anyway, return status 1; else return status 0.
     The ‘test’ subcommand is silent, apart from messages printed by the
     ‘$ZFTP_VERBOSE’ mechanism, or error messages if the connection
     closes.  There is no network overhead for this test.

     The test is only supported on systems with either the ‘select(2)’
     or ‘poll(2)’ system calls; otherwise the message ‘not supported on
     this system’ is printed instead.

     The ‘test’ subcommand will automatically be called at the start of
     any other subcommand for the current session when a connection is
     open.

‘cd’ DIRECTORY

     Change the remote directory to DIRECTORY.  Also alters the shell
     variable ‘ZFTP_PWD’.

‘cdup’

     Change the remote directory to the one higher in the directory
     tree.  Note that ‘cd ..’ will also work correctly on non-UNIX
     systems.

‘dir’ [ ARG … ]

     Give a (verbose) listing of the remote directory.  The ARGs are
     passed directly to the server.  The command’s behaviour is
     implementation dependent, but a UNIX server will typically
     interpret ARGs as arguments to the ‘ls’ command and with no
     arguments return the result of ‘ls -l’.  The directory is listed to
     standard output.

‘ls’ [ ARG … ]

     Give a (short) listing of the remote directory.  With no ARG,
     produces a raw list of the files in the directory, one per line.
     Otherwise, up to vagaries of the server implementation, behaves
     similar to ‘dir’.

‘type’ [ TYPE ]

     Change the type for the transfer to TYPE, or print the current type
     if TYPE is absent.  The allowed values are ‘A’ (ASCII), ‘I’ (Image,
     i.e.  binary), or ‘B’ (a synonym for ‘I’).

     The FTP default for a transfer is ASCII. However, if ‘zftp’ finds
     that the remote host is a UNIX machine with 8-bit byes, it will
     automatically switch to using binary for file transfers upon
     ‘open’.  This can subsequently be overridden.

     The transfer type is only passed to the remote host when a data
     connection is established; this command involves no network
     overhead.

‘ascii’

     The same as ‘type A’.

‘binary’

     The same as ‘type I’.

‘mode’ [ ‘S’ | ‘B’ ]

     Set the mode type to stream (‘S’) or block (‘B’).  Stream mode is
     the default; block mode is not widely supported.

‘remote’ FILE …

‘local’ [ FILE … ]

     Print the size and last modification time of the remote or local
     files.  If there is more than one item on the list, the name of the
     file is printed first.  The first number is the file size, the
     second is the last modification time of the file in the format
     ‘CCYYMMDDhhmmSS’ consisting of year, month, date, hour, minutes and
     seconds in GMT. Note that this format, including the length, is
     guaranteed, so that time strings can be directly compared via the
     ‘[[’ builtin’s ‘<’ and ‘>’ operators, even if they are too long to
     be represented as integers.

     Not all servers support the commands for retrieving this
     information.  In that case, the ‘remote’ command will print nothing
     and return status 2, compared with status 1 for a file not found.

     The ‘local’ command (but not ‘remote’) may be used with no
     arguments, in which case the information comes from examining file
     descriptor zero.  This is the same file as seen by a ‘put’ command
     with no further redirection.

‘get’ FILE …

     Retrieve all FILEs from the server, concatenating them and sending
     them to standard output.

‘put’ FILE …

     For each FILE, read a file from standard input and send that to the
     remote host with the given name.

‘append’ FILE …

     As ‘put’, but if the remote FILE already exists, data is appended
     to it instead of overwriting it.

‘getat’ FILE POINT

‘putat’ FILE POINT

‘appendat’ FILE POINT

     Versions of ‘get’, ‘put’ and ‘append’ which will start the transfer
     at the given POINT in the remote FILE.  This is useful for
     appending to an incomplete local file.  However, note that this
     ability is not universally supported by servers (and is not quite
     the behaviour specified by the standard).

‘delete’ FILE …

     Delete the list of files on the server.

‘mkdir’ DIRECTORY

     Create a new directory DIRECTORY on the server.

‘rmdir’ DIRECTORY

     Delete the directory DIRECTORY on the server.

‘rename’ OLD-NAME NEW-NAME

     Rename file OLD-NAME to NEW-NAME on the server.

‘site’ ARG …

     Send a host-specific command to the server.  You will probably only
     need this if instructed by the server to use it.

‘quote’ ARG …

     Send the raw FTP command sequence to the server.  You should be
     familiar with the FTP command set as defined in RFC959 before doing
     this.  Useful commands may include ‘STAT’ and ‘HELP’.  Note also
     the mechanism for returning messages as described for the variable
     ‘ZFTP_VERBOSE’ below, in particular that all messages from the
     control connection are sent to standard error.

‘close’

‘quit’

     Close the current data connection.  This unsets the shell
     parameters ‘ZFTP_HOST’, ‘ZFTP_PORT’, ‘ZFTP_IP’, ‘ZFTP_SYSTEM’,
     ‘ZFTP_USER’, ‘ZFTP_ACCOUNT’, ‘ZFTP_PWD’, ‘ZFTP_TYPE’ and
     ‘ZFTP_MODE’.

‘session’ [ SESSNAME ]

     Allows multiple FTP sessions to be used at once.  The name of the
     session is an arbitrary string of characters; the default session
     is called ‘default’.  If this command is called without an
     argument, it will list all the current sessions; with an argument,
     it will either switch to the existing session called SESSNAME, or
     create a new session of that name.

     Each session remembers the status of the connection, the set of
     connection-specific shell parameters (the same set as are unset
     when a connection closes, as given in the description of ‘close’),
     and any user parameters specified with the ‘params’ subcommand.
     Changing to a previous session restores those values; changing to a
     new session initialises them in the same way as if ‘zftp’ had just
     been loaded.  The name of the current session is given by the
     parameter ‘ZFTP_SESSION’.

‘rmsession’ [ SESSNAME ]

     Delete a session; if a name is not given, the current session is
     deleted.  If the current session is deleted, the earliest existing
     session becomes the new current session, otherwise the current
     session is not changed.  If the session being deleted is the only
     one, a new session called ‘default’ is created and becomes the
     current session; note that this is a new session even if the
     session being deleted is also called ‘default’.  It is recommended
     that sessions not be deleted while background commands which use
     ‘zftp’ are still active.


File: zsh.info,  Node: Parameters<5>,  Next: Functions<3>,  Prev: Subcommands,  Up: The zsh/zftp Module

21.35.2 Parameters
------------------

The following shell parameters are used by ‘zftp’.  Currently none of
them are special.

‘ZFTP_TMOUT’

     Integer.  The time in seconds to wait for a network operation to
     complete before returning an error.  If this is not set when the
     module is loaded, it will be given the default value 60.  A value
     of zero turns off timeouts.  If a timeout occurs on the control
     connection it will be closed.  Use a larger value if this occurs
     too frequently.

‘ZFTP_IP’

     Readonly.  The IP address of the current connection in dot
     notation.

‘ZFTP_HOST’

     Readonly.  The hostname of the current remote server.  If the host
     was opened as an IP number, ‘ZFTP_HOST’ contains that instead; this
     saves the overhead for a name lookup, as IP numbers are most
     commonly used when a nameserver is unavailable.

‘ZFTP_PORT’

     Readonly.  The number of the remote TCP port to which the
     connection is open (even if the port was originally specified as a
     named service).  Usually this is the standard FTP port, 21.

     In the unlikely event that your system does not have the
     appropriate conversion functions, this appears in network byte
     order.  If your system is little-endian, the port then consists of
     two swapped bytes and the standard port will be reported as 5376.
     In that case, numeric ports passed to ‘zftp open’ will also need to
     be in this format.

‘ZFTP_SYSTEM’

     Readonly.  The system type string returned by the server in
     response to an FTP ‘SYST’ request.  The most interesting case is a
     string beginning ‘"UNIX Type: L8"’, which ensures maximum
     compatibility with a local UNIX host.

‘ZFTP_TYPE’

     Readonly.  The type to be used for data transfers , either ‘A’ or
     ‘I’.  Use the ‘type’ subcommand to change this.

‘ZFTP_USER’

     Readonly.  The username currently logged in, if any.

‘ZFTP_ACCOUNT’

     Readonly.  The account name of the current user, if any.  Most
     servers do not require an account name.

‘ZFTP_PWD’

     Readonly.  The current directory on the server.

‘ZFTP_CODE’

     Readonly.  The three digit code of the last FTP reply from the
     server as a string.  This can still be read after the connection is
     closed, and is not changed when the current session changes.

‘ZFTP_REPLY’

     Readonly.  The last line of the last reply sent by the server.
     This can still be read after the connection is closed, and is not
     changed when the current session changes.

‘ZFTP_SESSION’

     Readonly.  The name of the current FTP session; see the description
     of the ‘session’ subcommand.

‘ZFTP_PREFS’

     A string of preferences for altering aspects of ‘zftp’’s behaviour.
     Each preference is a single character.  The following are defined:

     ‘P’

          Passive: attempt to make the remote server initiate data
          transfers.  This is slightly more efficient than sendport
          mode.  If the letter ‘S’ occurs later in the string, ‘zftp’
          will use sendport mode if passive mode is not available.

     ‘S’

          Sendport: initiate transfers by the FTP ‘PORT’ command.  If
          this occurs before any ‘P’ in the string, passive mode will
          never be attempted.

     ‘D’

          Dumb: use only the bare minimum of FTP commands.  This
          prevents the variables ‘ZFTP_SYSTEM’ and ‘ZFTP_PWD’ from being
          set, and will mean all connections default to ASCII type.  It
          may prevent ‘ZFTP_SIZE’ from being set during a transfer if
          the server does not send it anyway (many servers do).

     If ‘ZFTP_PREFS’ is not set when ‘zftp’ is loaded, it will be set to
     a default of ‘PS’, i.e.  use passive mode if available, otherwise
     fall back to sendport mode.

‘ZFTP_VERBOSE’

     A string of digits between 0 and 5 inclusive, specifying which
     responses from the server should be printed.  All responses go to
     standard error.  If any of the numbers 1 to 5 appear in the string,
     raw responses from the server with reply codes beginning with that
     digit will be printed to standard error.  The first digit of the
     three digit reply code is defined by RFC959 to correspond to:

       1. A positive preliminary reply.

       2. A positive completion reply.

       3. A positive intermediate reply.

       4. A transient negative completion reply.

       5. A permanent negative completion reply.

     It should be noted that, for unknown reasons, the reply ‘Service
     not available’, which forces termination of a connection, is
     classified as 421, i.e.  ‘transient negative’, an interesting
     interpretation of the word ‘transient’.

     The code 0 is special: it indicates that all but the last line of
     multiline replies read from the server will be printed to standard
     error in a processed format.  By convention, servers use this
     mechanism for sending information for the user to read.  The
     appropriate reply code, if it matches the same response, takes
     priority.

     If ‘ZFTP_VERBOSE’ is not set when ‘zftp’ is loaded, it will be set
     to the default value ‘450’, i.e., messages destined for the user
     and all errors will be printed.  A null string is valid and
     specifies that no messages should be printed.


File: zsh.info,  Node: Functions<3>,  Next: Problems,  Prev: Parameters<5>,  Up: The zsh/zftp Module

21.35.3 Functions
-----------------

‘zftp_chpwd’

     If this function is set by the user, it is called every time the
     directory changes on the server, including when a user is logged
     in, or when a connection is closed.  In the last case, ‘$ZFTP_PWD’
     will be unset; otherwise it will reflect the new directory.

‘zftp_progress’

     If this function is set by the user, it will be called during a
     ‘get’, ‘put’ or ‘append’ operation each time sufficient data has
     been received from the host.  During a ‘get’, the data is sent to
     standard output, so it is vital that this function should write to
     standard error or directly to the terminal, ‘not’ to standard
     output.

     When it is called with a transfer in progress, the following
     additional shell parameters are set:

     ‘ZFTP_FILE’

          The name of the remote file being transferred from or to.

     ‘ZFTP_TRANSFER’

          A ‘G’ for a ‘get’ operation and a ‘P’ for a ‘put’ operation.

     ‘ZFTP_SIZE’

          The total size of the complete file being transferred: the
          same as the first value provided by the ‘remote’ and ‘local’
          subcommands for a particular file.  If the server cannot
          supply this value for a remote file being retrieved, it will
          not be set.  If input is from a pipe the value may be
          incorrect and correspond simply to a full pipe buffer.

     ‘ZFTP_COUNT’

          The amount of data so far transferred; a number between zero
          and ‘$ZFTP_SIZE’, if that is set.  This number is always
          available.

     The function is initially called with ‘ZFTP_TRANSFER’ set
     appropriately and ‘ZFTP_COUNT’ set to zero.  After the transfer is
     finished, the function will be called one more time with
     ‘ZFTP_TRANSFER’ set to ‘GF’ or ‘PF’, in case it wishes to tidy up.
     It is otherwise never called twice with the same value of
     ‘ZFTP_COUNT’.

     Sometimes the progress meter may cause disruption.  It is up to the
     user to decide whether the function should be defined and to use
     ‘unfunction’ when necessary.


File: zsh.info,  Node: Problems,  Prev: Functions<3>,  Up: The zsh/zftp Module

21.35.4 Problems
----------------

A connection may not be opened in the left hand side of a pipe as this
occurs in a subshell and the file information is not updated in the main
shell.  In the case of type or mode changes or closing the connection in
a subshell, the information is returned but variables are not updated
until the next call to ‘zftp’.  Other status changes in subshells will
not be reflected by changes to the variables (but should be otherwise
harmless).

Deleting sessions while a ‘zftp’ command is active in the background can
have unexpected effects, even if it does not use the session being
deleted.  This is because all shell subprocesses share information on
the state of all connections, and deleting a session changes the
ordering of that information.

On some operating systems, the control connection is not valid after a
fork(), so that operations in subshells, on the left hand side of a
pipeline, or in the background are not possible, as they should be.
This is presumably a bug in the operating system.


File: zsh.info,  Node: The zsh/zle Module,  Next: The zsh/zleparameter Module,  Prev: The zsh/zftp Module,  Up: Zsh Modules

21.36 The zsh/zle Module
========================

The ‘zsh/zle’ module contains the Zsh Line Editor.  See ‘zshzle’.


File: zsh.info,  Node: The zsh/zleparameter Module,  Next: The zsh/zprof Module,  Prev: The zsh/zle Module,  Up: Zsh Modules

21.37 The zsh/zleparameter Module
=================================

The ‘zsh/zleparameter’ module defines two special parameters that can be
used to access internal information of the Zsh Line Editor (see
‘zshzle’).

‘keymaps’

     This array contains the names of the keymaps currently defined.

‘widgets’

     This associative array contains one entry per widget.  The name of
     the widget is the key and the value gives information about the
     widget.  It is either

          the string ‘builtin’ for builtin widgets, a string of the form
          ‘user:’NAME for user-defined widgets,

               where NAME is the name of the shell function implementing
               the widget,

          a string of the form ‘completion:’TYPE‘:’NAME

               for completion widgets,

          or a null value if the widget is not yet fully defined.

     In the penultimate case, TYPE is the name of the builtin widget the
     completion widget imitates in its behavior and NAME is the name of
     the shell function implementing the completion widget.


File: zsh.info,  Node: The zsh/zprof Module,  Next: The zsh/zpty Module,  Prev: The zsh/zleparameter Module,  Up: Zsh Modules

21.38 The zsh/zprof Module
==========================

When loaded, the ‘zsh/zprof’ causes shell functions to be profiled.  The
profiling results can be obtained with the ‘zprof’ builtin command made
available by this module.  There is no way to turn profiling off other
than unloading the module.

‘zprof’ [ ‘-c’ ]

     Without the ‘-c’ option, ‘zprof’ lists profiling results to
     standard output.  The format is comparable to that of commands like
     ‘gprof’.

     At the top there is a summary listing all functions that were
     called at least once.  This summary is sorted in decreasing order
     of the amount of time spent in each.  The lines contain the number
     of the function in order, which is used in other parts of the list
     in suffixes of the form ‘[’NUM‘]’, then the number of calls made to
     the function.  The next three columns list the time in milliseconds
     spent in the function and its descendants, the average time in
     milliseconds spent in the function and its descendants per call and
     the percentage of time spent in all shell functions used in this
     function and its descendants.  The following three columns give the
     same information, but counting only the time spent in the function
     itself.  The final column shows the name of the function.

     After the summary, detailed information about every function that
     was invoked is listed, sorted in decreasing order of the amount of
     time spent in each function and its descendants.  Each of these
     entries consists of descriptions for the functions that called the
     function described, the function itself, and the functions that
     were called from it.  The description for the function itself has
     the same format as in the summary (and shows the same information).
     The other lines don’t show the number of the function at the
     beginning and have their function named indented to make it easier
     to distinguish the line showing the function described in the
     section from the surrounding lines.

     The information shown in this case is almost the same as in the
     summary, but only refers to the call hierarchy being displayed.
     For example, for a calling function the column showing the total
     running time lists the time spent in the described function and its
     descendants only for the times when it was called from that
     particular calling function.  Likewise, for a called function, this
     columns lists the total time spent in the called function and its
     descendants only for the times when it was called from the function
     described.

     Also in this case, the column showing the number of calls to a
     function also shows a slash and then the total number of
     invocations made to the called function.

     As long as the ‘zsh/zprof’ module is loaded, profiling will be done
     and multiple invocations of the ‘zprof’ builtin command will show
     the times and numbers of calls since the module was loaded.  With
     the ‘-c’ option, the ‘zprof’ builtin command will reset its
     internal counters and will not show the listing.


File: zsh.info,  Node: The zsh/zpty Module,  Next: The zsh/zselect Module,  Prev: The zsh/zprof Module,  Up: Zsh Modules

21.39 The zsh/zpty Module
=========================

The ‘zsh/zpty’ module offers one builtin:

‘zpty’ [ ‘-e’ ] [ ‘-b’ ] NAME [ ARG … ]

     The arguments following NAME are concatenated with spaces between,
     then executed as a command, as if passed to the ‘eval’ builtin.
     The command runs under a newly assigned pseudo-terminal; this is
     useful for running commands non-interactively which expect an
     interactive environment.  The NAME is not part of the command, but
     is used to refer to this command in later calls to ‘zpty’.

     With the ‘-e’ option, the pseudo-terminal is set up so that input
     characters are echoed.

     With the ‘-b’ option, input to and output from the pseudo-terminal
     are made non-blocking.

     The shell parameter ‘REPLY’ is set to the file descriptor assigned
     to the master side of the pseudo-terminal.  This allows the
     terminal to be monitored with ZLE descriptor handlers (see the
     description of option ‘-F’ for ‘zle’ builtin in *note Zle Builtins:
     ba.) or manipulated with ‘sysread’ and ‘syswrite’ builtins (see
     *note The zsh/system Module: 11f.).  ‘Warning’: Use of ‘sysread’
     and ‘syswrite’ is ‘not’ recommended; use ‘zpty -r’ and ‘zpty -w’
     unless you know exactly what you are doing.

‘zpty’ ‘-d’ [ NAME … ]

     The ‘-d’ option is used to delete commands previously started, by
     supplying a list of their NAMEs.  If no NAME is given, all commands
     are deleted.  Deleting a command causes the HUP signal to be sent
     to the corresponding process.  It is not a good idea to use this
     form in a subshell, as it will kill the command but leave the
     parent shell confused about the state, and it may try to kill
     another process that re-used the process ID.

‘zpty’ ‘-w’ [ ‘-n’ ] NAME [ STRING … ]

     The ‘-w’ option can be used to send the to command NAME the given
     STRINGs as input (separated by spaces).  If the ‘-n’ option is
     ‘not’ given, a newline is added at the end.

     If no STRING is provided, the standard input is copied to the
     pseudo-terminal; this may stop before copying the full input if the
     pseudo-terminal is non-blocking.  The exact input is always copied:
     the ‘-n’ option is not applied.

     Note that the command under the pseudo-terminal sees this input as
     if it were typed, so beware when sending special tty driver
     characters such as word-erase, line-kill, and end-of-file.

‘zpty’ ‘-r’ [ ‘-mt’ ] NAME [ PARAM [ PATTERN ] ]

     The ‘-r’ option can be used to read the output of the command NAME.
     With only a NAME argument, the output read is copied to the
     standard output.  Unless the pseudo-terminal is non-blocking,
     copying continues until the command under the pseudo-terminal
     exits; when non-blocking, only as much output as is immediately
     available is copied.  The return status is zero if any output is
     copied.

     When also given a PARAM argument, at most one line is read and
     stored in the parameter named PARAM.  Less than a full line may be
     read if the pseudo-terminal is non-blocking.  The return status is
     zero if at least one character is stored in PARAM.

     If a PATTERN is given as well, output is read until the whole
     string read matches the PATTERN, even in the non-blocking case.
     The return status is zero if the string read matches the pattern,
     or if the command has exited but at least one character could still
     be read.  If the option ‘-m’ is present, the return status is zero
     only if the pattern matches.  As of this writing, a maximum of one
     megabyte of output can be consumed this way; if a full megabyte is
     read without matching the pattern, the return status is non-zero.

     In all cases, the return status is non-zero if nothing could be
     read, and is ‘2’ if this is because the command has finished.

     If the ‘-r’ option is combined with the ‘-t’ option, ‘zpty’ tests
     whether output is available before trying to read.  If no output is
     available, ‘zpty’ immediately returns the status ‘1’.  When used
     with a PATTERN, the behaviour on a failed poll is similar to when
     the command has exited: the return value is zero if at least one
     character could still be read even if the pattern failed to match.

‘zpty’ ‘-t’ NAME

     The ‘-t’ option without the ‘-r’ option can be used to test whether
     the command NAME is still running.  It returns a zero status if the
     command is running and a non-zero value otherwise.  Note that this
     does not indicate whether or not any output is available to read.

‘zpty’ [ ‘-L’ ]

     The last form, without any arguments, is used to list the commands
     currently defined.  If the ‘-L’ option is given, this is done in
     the form of calls to the ‘zpty’ builtin.


File: zsh.info,  Node: The zsh/zselect Module,  Next: The zsh/zutil Module,  Prev: The zsh/zpty Module,  Up: Zsh Modules

21.40 The zsh/zselect Module
============================

The ‘zsh/zselect’ module makes available one builtin command:

‘zselect’ [ ‘-rwe’ ] [ ‘-t’ TIMEOUT ] [ ‘-a’ ARRAY ] [ ‘-A’ ASSOC ] [ FD
… ]

     The ‘zselect’ builtin is a front-end to the ‘select’ system call,
     which blocks until a file descriptor is ready for reading or
     writing, or has an error condition, with an optional timeout.  If
     this is not available on your system, the command prints an error
     message and returns status 2 (normal errors return status 1).  For
     more information, see your system’s documentation for ‘select(2)’.
     Note there is no connection with the shell builtin of the same
     name.

     Arguments and options may be intermingled in any order.  Non-option
     arguments are file descriptors, which must be decimal integers.  By
     default, file descriptors are to be tested for reading, i.e.
     ‘zselect’ will return when data is available to be read from the
     file descriptor, or more precisely, when a read operation from the
     file descriptor will not block.  After a ‘-r’, ‘-w’ and ‘-e’, the
     given file descriptors are to be tested for reading, writing, or
     error conditions.  These options and an arbitrary list of file
     descriptors may be given in any order.

     (The presence of an ‘error condition’ is not well defined in the
     documentation for many implementations of the select system call.
     According to recent versions of the POSIX specification, it is
     really an ‘exception’ condition, of which the only standard example
     is out-of-band data received on a socket.  So zsh users are
     unlikely to find the ‘-e’ option useful.)

     The option ‘-t’ TIMEOUT specifies a timeout in hundredths of a
     second.  This may be zero, in which case the file descriptors will
     simply be polled and ‘zselect’ will return immediately.  It is
     possible to call zselect with no file descriptors and a non-zero
     timeout for use as a finer-grained replacement for ‘sleep’; note,
     however, the return status is always 1 for a timeout.

     The option ‘-a’ ARRAY indicates that ARRAY should be set to
     indicate the file descriptor(s) which are ready.  If the option is
     not given, the array ‘reply’ will be used for this purpose.  The
     array will contain a string similar to the arguments for ‘zselect’.
     For example,

           zselect -t 0 -r 0 -w 1

     might return immediately with status 0 and ‘$reply’ containing ‘-r
     0 -w 1’ to show that both file descriptors are ready for the
     requested operations.

     The option ‘-A’ ASSOC indicates that the associative array ASSOC
     should be set to indicate the file descriptor(s) which are ready.
     This option overrides the option ‘-a’, nor will ‘reply’ be
     modified.  The keys of ‘assoc’ are the file descriptors, and the
     corresponding values are any of the characters ‘rwe’ to indicate
     the condition.

     The command returns status 0 if some file descriptors are ready for
     reading.  If the operation timed out, or a timeout of 0 was given
     and no file descriptors were ready, or there was an error, it
     returns status 1 and the array will not be set (nor modified in any
     way).  If there was an error in the select operation the
     appropriate error message is printed.


File: zsh.info,  Node: The zsh/zutil Module,  Prev: The zsh/zselect Module,  Up: Zsh Modules

21.41 The zsh/zutil Module
==========================

The ‘zsh/zutil’ module only adds some builtins:

‘zstyle’ [ ‘-L’ [ METAPATTERN [ STYLE ] ] ]

‘zstyle’ [ ‘-e’ | ‘-’ | ‘--’ ] PATTERN STYLE STRING …

‘zstyle -d’ [ PATTERN [ STYLE … ] ]

‘zstyle -g’ NAME [ PATTERN [ STYLE ] ]

‘zstyle -q’ CONTEXT STYLE

‘zstyle -{a|b|s’} CONTEXT STYLE NAME [ SEP ]

‘zstyle -{T|t’} CONTEXT STYLE [ STRING … ]

‘zstyle -m’ CONTEXT STYLE PATTERN

     This builtin command is used to define and lookup styles.  Styles
     are pairs of names and values, where the values consist of any
     number of strings.  They are stored together with patterns and
     lookup is done by giving a string, called the ‘context’, which is
     matched against the patterns.  The definition stored for the most
     specific pattern that matches will be returned.

     A pattern is considered to be more specific than another if it
     contains more components (substrings separated by colons) or if the
     patterns for the components are more specific, where simple strings
     are considered to be more specific than patterns and complex
     patterns are considered to be more specific than the pattern ‘*’.
     A ‘*’ in the pattern will match zero or more characters in the
     context; colons are not treated specially in this regard.  If two
     patterns are equally specific, the tie is broken in favour of the
     pattern that was defined first.

     ‘Example’ ..  index:: single: preferred-precipitation, example
     style; Keystroke

     For example, a fictional ‘weather’ plugin might state in its
     documentation that it looks up the ‘preferred-precipitation’ style
     under the
     ‘:weather:’CONTINENT‘:’DAY-OF-THE-WEEK‘:’PHASE-OF-THE-MOON context.
     According to this, you might set the following in your ‘zshrc’:

           zstyle ':weather:europe:*' preferred-precipitation rain
           zstyle ':weather:*:Sunday:*' preferred-precipitation snow

     Then the plugin would run under the hood a command such as

           zstyle -s \
             ":weather:${continent}:${day_of_week}:${moon_phase}" \
             preferred-precipitation REPLY

     in order to retrieve your preference into the scalar variable
     ‘$REPLY’.  On Sundays ‘$REPLY’ would be set to ‘snow’; in Europe it
     would be set to ‘rain’; and on Sundays in Europe it would be set to
     ‘snow’ again, because the patterns ‘:weather:europe:*’ and
     ‘:weather:*:Sunday:*’ both match the CONTEXT argument to ‘zstyle
     -s’, are equally specific, and the latter is more specific (because
     it has more colon-separated components).

     ‘Usage’

     The forms that operate on patterns are the following.

     ‘zstyle’ [ ‘-L’ [ METAPATTERN [ STYLE ] ] ]

          Without arguments, lists style definitions.  Styles are shown
          in alphabetic order and patterns are shown in the order
          ‘zstyle’ will test them.

          If the ‘-L’ option is given, listing is done in the form of
          calls to ‘zstyle’.  The optional first argument, METAPATTERN,
          is a pattern which will be matched against the string supplied
          as PATTERN when the style was defined.  Note: this means, for
          example, ‘zstyle -L ":completion:*"’ will match any supplied
          pattern beginning ‘:completion:’, not just ‘":completion:*"’:
          use ‘':completion:\*'’ to match that.  The optional second
          argument limits the output to a specific STYLE (not a
          pattern).  ‘-L’ is not compatible with any other options.

     ‘zstyle’ [ ‘-’ | ‘--’ | ‘-e’ ] PATTERN STYLE STRING …

          Defines the given STYLE for the PATTERN with the STRINGs as
          the value.  If the ‘-e’ option is given, the STRINGs will be
          concatenated (separated by spaces) and the resulting string
          will be evaluated (in the same way as it is done by the ‘eval’
          builtin command) when the style is looked up.  In this case
          the parameter ‘reply’ must be assigned to set the strings
          returned after the evaluation.  Before evaluating the value,
          ‘reply’ is unset, and if it is still unset after the
          evaluation, the style is treated as if it were not set.

     ‘zstyle -d’ [ PATTERN [ STYLE … ] ]

          Delete style definitions.  Without arguments all definitions
          are deleted, with a PATTERN all definitions for that pattern
          are deleted and if any STYLEs are given, then only those
          styles are deleted for the PATTERN.

     ‘zstyle -g’ NAME [ PATTERN [ STYLE ] ]

          Retrieve a style definition.  The NAME is used as the name of
          an array in which the results are stored.  Without any further
          arguments, all patterns defined are returned.  With a PATTERN
          the styles defined for that pattern are returned and with both
          a PATTERN and a STYLE, the value strings of that combination
          is returned.

     The other forms can be used to look up or test styles for a given
     context.

     ‘zstyle -q’ CONTEXT STYLE

          Return ‘0’ if STYLE is defined in CONTEXT.  This does not
          evaluate expressions defined by ‘zstyle -e’ and does not
          examine any values set by STYLE.  The expected use is to test
          whether a style has been defined for CONTEXT before asserting
          a new style.

     ‘zstyle -s’ CONTEXT STYLE NAME [ SEP ]

          The parameter NAME is set to the value of the style
          interpreted as a string.  If the value contains several
          strings they are concatenated with spaces (or with the SEP
          string if that is given) between them.

          Return ‘0’ if the style is set, ‘1’ otherwise.

     ‘zstyle -b’ CONTEXT STYLE NAME

          The value is stored in NAME as a boolean, i.e.  as the string
          ‘yes’ if the value has only one string and that string is
          equal to one of ‘yes’, ‘true’, ‘on’, or ‘1’.  If the value is
          any other string or has more than one string, the parameter is
          set to ‘no’.

          Return ‘0’ if NAME is set to ‘yes’, ‘1’ otherwise.

     ‘zstyle -a’ CONTEXT STYLE NAME

          The value is stored in NAME as an array.  If NAME is declared
          as an associative array, the first, third, etc.  strings are
          used as the keys and the other strings are used as the values.

          Return ‘0’ if the style is set, ‘1’ otherwise.

     ‘zstyle -t’ CONTEXT STYLE [ STRING … ]

     ‘zstyle -T’ CONTEXT STYLE [ STRING … ]

          Test the value of a style, i.e.  the ‘-t’ option only returns
          a status (sets ‘$?’).  Without any STRING the return status is
          zero if the style is defined for at least one matching
          pattern, has only one string in its value, and that is equal
          to one of ‘true’, ‘yes’, ‘on’ or ‘1’.  If any STRINGs are
          given the status is zero if and only if at least one of the
          STRINGs is equal to at least one of the strings in the value.
          If the style is defined but doesn’t match, the return status
          is ‘1’.  If the style is not defined, the status is ‘2’.

          The ‘-T’ option tests the values of the style like ‘-t’, but
          it returns status zero (rather than ‘2’) if the style is not
          defined for any matching pattern.

     ‘zstyle -m’ CONTEXT STYLE PATTERN

          Match a value.  Returns status zero if the PATTERN matches at
          least one of the strings in the value.

‘zformat -f’ [ ‘-qQ’ ] ] PARAM FORMAT SPEC …

‘zformat -F’ [ ‘-qQ’ ] ] PARAM FORMAT SPEC …

‘zformat -a’ ARRAY SEP SPEC …

     This builtin provides different forms of formatting.

     The first form is selected with the ‘-f’ option.  In this case the
     FORMAT string will be modified by replacing sequences starting with
     a percent sign in it with strings from the SPECs.  Each SPEC should
     be of the form CHAR‘:’STRING which will cause every appearance of
     the sequence ‘%’CHAR in FORMAT to be replaced by the STRING.  The
     ‘%’ sequence may also contain optional minimum and maximum field
     width specifications between the ‘%’ and the CHAR in the form
     ‘%’MIN‘.’MAX‘c’, i.e.  the minimum field width is given first and
     if the maximum field width is used, it has to be preceded by a dot.
     Specifying a minimum field width makes the result be padded with
     spaces to the right if the STRING is shorter than the requested
     width.  Padding to the left can be achieved by giving a negative
     minimum field width.  If a maximum field width is specified, the
     STRING will be truncated after that many characters.

     The CHAR in each SPEC may optionally be preceded by an escaping
     indicator, either ‘%’ to explicitly enable the SPEC-escaping
     behaviour of ‘-q’ described below, or ‘%%’ to explicitly disable
     it.  The default behaviour is to ‘not’ escape specs.

     Any ‘%’ sequence in ‘format’ that does not match a given SPEC (or
     one of the special sequences described below) is output as-is.  If
     desired, these sequences may be processed by a second round of
     formatting, by prompt expansion, etc.  – see also ‘-q’.

     The sequence ‘%%’ can be used to produce a literal ‘%’.  After all
     ‘%’ sequences have been processed, the resulting string is stored
     in the parameter PARAM.

     The ‘%’-escapes also understand ternary expressions in the form
     used by prompts.  The ‘%’ is followed by a ‘(’ and then an ordinary
     format specifier character as described above.  There may be a set
     of digits either before or after the ‘(’; these specify a test
     number, which defaults to zero.  Negative numbers are also allowed.
     An arbitrary delimiter character follows the format specifier,
     which is followed by a piece of ‘true’ text, the delimiter
     character again, a piece of ‘false’ text, and a closing
     parenthesis.  The complete expression (without the digits) thus
     looks like ‘%(’X‘.’TEXT1‘.’TEXT2‘)’, except that the ‘.’ character
     is arbitrary.  The value given for the format specifier in the
     CHAR‘:’STRING expressions is evaluated as a mathematical
     expression, and compared with the test number.  If they are the
     same, TEXT1 is output, else TEXT2 is output.  A parenthesis may be
     escaped in TEXT2 as ‘%)’.  Either of TEXT1 or TEXT2 may contain
     nested ‘%’-escapes.

     For example:

           zformat -f REPLY "The answer is '%3(c.yes.no)'." c:3

     outputs “The answer is ‘yes’.” to ‘REPLY’ since the value for the
     format specifier ‘c’ is 3, agreeing with the digit argument to the
     ternary expression.

     With ‘-F’ instead of ‘-f’, ternary expressions choose between the
     ‘true’ or ‘false’ text on the basis of whether the format specifier
     is present and non-empty.  If a test number is provided, it tests
     the width of the value given in the format specifier – with a
     positive number the condition is true when the width is ‘greater
     than’ that number, and with a negative number the condition is true
     when the width is ‘less than or equal to’ the absolute value of
     that number.

     With ‘-q’, ‘%’ characters in the SPECs are escaped by default as
     they are inserted into the formatted string, and pre-escaped ‘%’
     and ‘`)’‘ characters in the format string are left as they are.
     For example:

           zformat -qF REPLY '%%foo%% %B%d%b' d:%bar%

     outputs ‘%%foo%% %B%%bar%%%b’ to ‘REPLY’.  This is useful when the
     formatted string will undergo further expansion – in this example
     the ‘%B...%b’ sequences could be used with prompt expansion to
     produce bold text.  One notable use case is formatting a
     description to be passed to ‘compadd -x’ in a completion function.

     Since the output with ‘-q’ is expected to be subject to further
     processing, width specifiers don’t count the extra escape
     characters, ensuring that the widths are correct ‘after’ that
     processing.  Additionally, with ‘-F’, ternary-expression test
     numbers are compared against the ‘pre-escaped’ spec lengths.

     ‘-Q’ is like ‘-q’ except that it interprets pre-escaped ‘%’ and
     ‘`)’ characters in the format string as normal.

     The optional escaping indicator can be used to exempt individual
     SPECs from escaping as described above.  For example:

           zformat -qF REPLY %d %D' d:%foo% %%D:%bar%

     outputs ‘%%foo%% %bar%’ to ‘REPLY’.

     The form using the ‘-a’ option can be used for aligning strings.
     Here, the SPECs are of the form LEFT‘:’RIGHT where LEFT and RIGHT
     are arbitrary strings.  These strings are modified by replacing the
     colons by the SEP string and padding the LEFT strings with spaces
     to the right so that the SEP strings in the result (and hence the
     RIGHT strings after them) are all aligned if the strings are
     printed below each other.  All strings without a colon are left
     unchanged and all strings with an empty RIGHT string have the
     trailing colon removed.  In both cases the lengths of the strings
     are not used to determine how the other strings are to be aligned.
     A colon in the LEFT string can be escaped with a backslash.  The
     resulting strings are stored in the ARRAY.

‘zregexparse’

     This implements some internals of the ‘_regex_arguments’ function.

‘zparseopts’ [ ‘-DEFGKM’ ] [ ‘-a’ ARRAY ] [ ‘-A’ ASSOC ] [ ‘-n’ NAME ] [
‘-v’ ARGV ] [ ‘-’ ] SPEC …

     This builtin simplifies the parsing of options in positional
     parameters, i.e.  the set of arguments given by ‘$*’.  Each SPEC
     describes one option and must be of the form OPT[‘=’ARRAY].  If an
     option described by OPT is found in the positional parameters it is
     copied into the ARRAY specified with the ‘-a’ option; if the
     optional ‘=’ARRAY is given, it is instead copied into that array,
     which should be declared as a normal array and never as an
     associative array.

     At least one SPEC must be given.  If a single spec is given which
     is either an empty string or a single hyphen (as in ‘zparseopts -DF
     ''’), it signifies that no options are recognised.  (This is useful
     for future-proofing functions that might gain options later.)
     Otherwise, it is an error to give any SPEC without an ‘=’ARRAY
     unless one of the ‘-a’ or ‘-A’ options is used.

     Unless the ‘-E’ option is given, parsing stops at the first string
     that isn’t described by one of the SPECs.  Even with ‘-E’, parsing
     always stops at a positional parameter equal to ‘--’ or (without
     ‘-G’) ‘-’.  See also ‘-F’.

     The OPT description must be one of the following.  Any of the
     special characters can appear in the option name provided it is
     preceded by a backslash.

     NAME

     NAME‘+’

          The NAME is the name of the option without the leading ‘-’.
          To specify a GNU-style long option, one of the usual two
          leading ‘-’ must be included in NAME; for example, a ‘--file’
          option is represented by a NAME of ‘-file’.

          If a ‘+’ appears after NAME, the option is appended to ARRAY
          each time it is found in the positional parameters; without
          the ‘+’ only the ‘last’ occurrence of the option is preserved.

          If one of these forms is used, the option takes no argument,
          so parsing stops if the next positional parameter does not
          also begin with ‘-’ (unless the ‘-E’ option is used).

     NAME‘:’

     NAME‘:-’

     NAME‘::’

          If one or two colons are given, the option takes an argument;
          with one colon, the argument is mandatory and with two colons
          it is optional.  The argument is appended to the ARRAY after
          the option itself.

          An optional argument is put into the same array element as the
          option name (note that this makes empty strings as arguments
          indistinguishable).  A mandatory argument is added as a
          separate element unless the ‘:-’ form is used, in which case
          the argument is put into the same element.

          A ‘+’ as described above may appear between the NAME and the
          first colon.

     By default, option-arguments may appear either immediately
     following the option in the same positional parameter or in the
     next one.  Even an optional argument may appear in the next
     parameter, unless it begins with a ‘-’.  Additionally, there is no
     special consideration given to an ‘=’ between an option and its
     argument.  To make parsing use the more common GNU-style
     conventions, use the ‘-G’ option.

     When the names of two options that take no arguments overlap, the
     longest one wins, so that parsing for the SPECs ‘-foo -foobar’ (for
     example) is unambiguous.  However, due to the aforementioned
     handling of option-arguments, ambiguities may arise when at least
     one overlapping SPEC takes an argument, as in ‘-foo: -foobar’.  In
     that case, the last matching SPEC wins.  (This is not an issue with
     GNU-style parsing.)

     In order to distinguish GNU-style long option SPECs from
     ‘zparseopts’’s own options, they ‘must’ be preceded by a ‘-’, ‘--’,
     or short option ‘spec’, as in ‘zparseopts -Ga opts - -foo’.

     The options of ‘zparseopts’ itself are:

     ‘-a’ ARRAY

          As described above, this names the default array in which to
          store the recognised options.

     ‘-A’ ASSOC

          If this is given, the options and their values are also put
          into an associative array with the option names as keys and
          the arguments (if any) as the values.

     ‘-D’

          If this option is given, all options found are removed from
          the positional parameters of the calling shell or shell
          function, up to but not including any not described by the
          SPECs.  If the first such parameter is ‘--’ or (without ‘-G’)
          ‘-’, it is removed as well.  This is similar to using the
          ‘shift’ builtin.

     ‘-E’

          This changes the parsing rules to ‘not’ stop at the first
          string that isn’t described by one of the SPECs.  It can be
          used to test for or (if used together with ‘-D’) extract
          options and their arguments, ignoring all other options and
          arguments that may be in the positional parameters.  As
          indicated above, parsing still stops at the first ‘-’ or ‘--’
          not described by a SPEC, but it is not removed when used with
          ‘-D’.

     ‘-F’

          If this option is given, ‘zparseopts’ immediately stops at the
          first option-like parameter not described by one of the SPECs,
          prints an error message, and returns status 1.  Removal (‘-D’)
          and extraction (‘-E’) are not performed, and option arrays are
          not updated.  This provides basic validation for the given
          options.

          Note that the appearance in the positional parameters of an
          option without its required argument always aborts parsing and
          returns an error as described above regardless of whether this
          option is used.

     ‘-G’

          This option specifies that options are parsed in the GNU
          style, similar to ‘getopt_long(3)’.  In particular:

          Given the SPEC ‘-foo:’, the positional parameter ‘--foo=bar’
          is interpreted as option ‘--foo’ with argument ‘bar’, rather
          than argument ‘=bar’ as is the default, whilst the positional
          parameter ‘--foobar’ is considered an unknown option (unless
          another SPEC describes it).  This applies to both singly and
          doubly hyphenated long options.

          An empty option-argument can be given to its long option in
          the same parameter using a trailing ‘=’.

          An optional argument to a long option must be given with the
          equals syntax, and an optional argument to a short option must
          follow it immediately in the same parameter; in both cases the
          following parameter is considered unrelated.

          Whenever a long option and its argument are stored in the same
          array element, an ‘=’ is used to separate them.

          A mandatory option-argument given in a separate parameter from
          its option (as in ‘--foo’ ‘bar’), or any option-argument given
          to a short option in the same parameter, is always treated the
          same regardless of whether this option is in effect.

          Lastly, when this option is active, only ‘--’ is treated as an
          explicit option-parsing terminator in the parsed arguments; a
          single ‘-’ is considered a normal operand.

          Note: Unlike most ‘getopt_long(3)’ implementations,
          ‘zparseopts’ does not support abbreviating long options.

     ‘-K’

          With this option, the arrays specified with the ‘-a’ option
          and with the ‘=’ARRAY forms are kept unchanged when none of
          the SPECs for them is used.  Otherwise the entire array is
          replaced when any of the SPECs is used.  Individual elements
          of associative arrays specified with the ‘-A’ option are
          preserved by ‘-K’.  This allows assignment of default values
          to arrays before calling ‘zparseopts’.

     ‘-M’

          This changes the assignment rules to implement a map among
          equivalent option names.  If any SPEC uses the ‘=’ARRAY form,
          the string ARRAY is interpreted as the name of another SPEC,
          which is used to choose where to store the values.  Values
          stored in an associative array (‘-A’) use the name of the
          mapped-to option, whereas values stored in an array use the
          last as-given option name.  If no other SPEC is found, the
          values are stored as usual.  This changes only the way the
          values are stored, not the way ‘$*’ is parsed, so results may
          be unpredictable if the NAME‘+’ specifier is used
          inconsistently.

     ‘-n’ NAME

          If this option is given, NAME is used when printing usage
          errors intended for the end user.  Otherwise, the name of the
          calling function or script is used.  Error messages arising
          from misusage of ‘zparseopts’ itself are not affected by this
          option.

     ‘-v’ ARGV

          With this option, the elements of the named array ARGV are
          used as the positional parameters to parse, rather than those
          given by ‘$*’.  The array may be modified according to the
          ‘-D’ option.

     For example,

           set -- -a -bx -c y -cz baz -cend
           zparseopts a=foo b:=bar c+:=bar

     will have the effect of

           foo=(-a)
           bar=(-b x -c y -c z)

     The arguments from ‘baz’ on will not be used.

     As an example for the ‘-E’ option, consider:

           set -- -a x -b y -c z arg1 arg2
           zparseopts -E -D b:=bar

     will have the effect of

           bar=(-b y)
           set -- -a x -c z arg1 arg2

     I.e., the option ‘-b’ and its arguments are taken from the
     positional parameters and put into the array ‘bar’.

     The ‘-M’ option can be used like this:

           set -- -a -bx -c y -cz baz -cend
           zparseopts -A bar -M a=foo b+: c:=b

     to have the effect of

           foo=(-a)
           bar=(-a '' -b xyz)

The following is a useful general-purpose pattern:

      local -A opts
      zparseopts -DFGA opts - x -long: || return
      (( $+opts[-x] )) && ... # handle -x
      (( $+opts[--long] )) && ... # handle --long, optarg in $opts[--long]


File: zsh.info,  Node: Calendar Function System,  Next: TCP Function System,  Prev: Zsh Modules,  Up: Top

22 Calendar Function System
***************************

* Menu:

* Description: Description<7>.
* File and Date Formats::
* User Functions::
* Styles::
* Utility functions::
* Bugs::


File: zsh.info,  Node: Description<7>,  Next: File and Date Formats,  Up: Calendar Function System

22.1 Description
================

The shell is supplied with a series of functions to replace and enhance
the traditional Unix ‘calendar’ programme, which warns the user of
imminent or future events, details of which are stored in a text file
(typically ‘calendar’ in the user’s home directory).  The version
provided here includes a mechanism for alerting the user when an event
is due.

In addition functions ‘age’, ‘before’ and ‘after’ are provided that can
be used in a glob qualifier; they allow files to be selected based on
their modification times.

The format of the ‘calendar’ file and the dates used there in and in the
‘age’ function are described first, then the functions that can be
called to examine and modify the ‘calendar’ file.

The functions here depend on the availability of the ‘zsh/datetime’
module which is usually installed with the shell.  The library function
‘strptime()’ must be available; it is present on most recent operating
systems.


File: zsh.info,  Node: File and Date Formats,  Next: User Functions,  Prev: Description<7>,  Up: Calendar Function System

22.2 File and Date Formats
==========================

* Menu:

* Calendar File Format::
* Date Format::
* Relative Time Format::
* Example: Example<3>.


File: zsh.info,  Node: Calendar File Format,  Next: Date Format,  Up: File and Date Formats

22.2.1 Calendar File Format
---------------------------

The calendar file is by default ‘~/calendar’.  This can be configured by
the ‘calendar-file’ style, see *note Styles: 16c.  The basic format
consists of a series of separate lines, with no indentation, each
including a date and time specification followed by a description of the
event.

Various enhancements to this format are supported, based on the syntax
of Emacs calendar mode.  An indented line indicates a continuation line
that continues the description of the event from the preceding line
(note the date may not be continued in this way).  An initial ampersand
(‘&’) is ignored for compatibility.

An indented line on which the first non-whitespace character is ‘#’ is
not displayed with the calendar entry, but is still scanned for
information.  This can be used to hide information useful to the
calendar system but not to the user, such as the unique identifier used
by ‘calendar_add’.

The Emacs extension that a date with no description may refer to a
number of succeeding events at different times is not supported.

Unless the ‘done-file’ style has been altered, any events which have
been processed are appended to the file with the same name as the
calendar file with the suffix ‘.done’, hence ‘~/calendar.done’ by
default.

An example is shown below.


File: zsh.info,  Node: Date Format,  Next: Relative Time Format,  Prev: Calendar File Format,  Up: File and Date Formats

22.2.2 Date Format
------------------

The format of the date and time is designed to allow flexibility without
admitting ambiguity.  (The words ‘date’ and ‘time’ are both used in the
documentation below; except where specifically noted this implies a
string that may include both a date and a time specification.)  Note
that there is no localization support; month and day names must be in
English and separator characters are fixed.  Matching is case
insensitive, and only the first three letters of the names are
significant, although as a special case a form beginning “month” does
not match “Monday”.  Furthermore, time zones are not handled; all times
are assumed to be local.

It is recommended that, rather than exploring the intricacies of the
system, users find a date format that is natural to them and stick to
it.  This will avoid unexpected effects.  Various key facts should be
noted.

        * In particular, note the confusion between

     MONTH‘/’DAY‘/’YEAR and DAY‘/’MONTH‘/’YEAR when the month is
     numeric; these formats should be avoided if at all possible.  Many
     alternatives are available.  * The year must be given in full to
     avoid confusion, and only years from 1900 to 2099 inclusive are
     matched.

The following give some obvious examples; users finding here a format
they like and not subject to vagaries of style may skip the full
description.  As dates and times are matched separately (even though the
time may be embedded in the date), any date format may be mixed with any
format for the time of day provide the separators are clear (whitespace,
colons, commas).

      2007/04/03 13:13
      2007/04/03:13:13
      2007/04/03 1:13 pm
      3rd April 2007, 13:13
      April 3rd 2007 1:13 p.m.
      Apr 3, 2007 13:13
      Tue Apr 03 13:13:00 2007
      13:13 2007/apr/3

More detailed rules follow.

Times are parsed and extracted before dates.  They must use colons to
separate hours and minutes, though a dot is allowed before seconds if
they are present.  This limits time formats to the following:

        * HH‘:’MM[‘:’SS[‘.’FFFFF]] [‘am|pm|a.m.|p.m.’]

        * HH‘:’MM‘.’SS[‘.’FFFFF] [‘am|pm|a.m.|p.m.’]

Here, square brackets indicate optional elements, possibly with
alternatives.  Fractions of a second are recognised but ignored.  For
absolute times (the normal format require by the ‘calendar’ file and the
‘age’, ‘before’ and ‘after’ functions) a date is mandatory but a time of
day is not; the time returned is at the start of the date.  One
variation is allowed: if ‘a.m.’ or ‘p.m.’ or one of their variants is
present, an hour without a minute is allowed, e.g.  ‘3 p.m.’.

Time zones are not handled, though if one is matched following a time
specification it will be removed to allow a surrounding date to be
parsed.  This only happens if the format of the timezone is not too
unusual.  The following are examples of forms that are understood:

      +0100
      GMT
      GMT-7
      CET+1CDT

Any part of the timezone that is not numeric must have exactly three
capital letters in the name.

Dates suffer from the ambiguity between DD‘/’MM‘/’YYYY and
MM‘/’DD‘/’YYYY.  It is recommended this form is avoided with purely
numeric dates, but use of ordinals, eg.  ‘3rd/04/2007’, will resolve the
ambiguity as the ordinal is always parsed as the day of the month.
Years must be four digits (and the first two must be ‘19’ or ‘20’);
‘03/04/08’ is not recognised.  Other numbers may have leading zeroes,
but they are not required.  The following are handled:

        * YYYY‘/’MM‘/’DD

        * YYYY‘-’MM‘-’DD

        * YYYY‘/’MNM‘/’DD

        * YYYY‘-’MNM‘-’DD

        * DD[‘th|st|rd’] MNM[‘,’] [ YYYY ]

        * MNM DD[‘th|st|rd][,’] [ YYYY ]

        * DD[‘th|st|rd]/’MM[‘,’] YYYY

        * DD[‘th|st|rd]/’MM‘/’YYYY

        * MM‘/’DD[‘th|st|rd][,’] YYYY

        * MM‘/’DD[‘th|st|rd]/’YYYY

Here, MNM is at least the first three letters of a month name, matched
case-insensitively.  The remainder of the month name may appear but its
contents are irrelevant, so janissary, febrile, martial, apricot, maybe,
junta, etc.  are happily handled.

Where the year is shown as optional, the current year is assumed.  There
are only two such cases, the form ‘Jun 20’ or ‘14 September’ (the only
two commonly occurring forms, apart from a “the” in some forms of
English, which isn’t currently supported).  Such dates will of course
become ambiguous in the future, so should ideally be avoided.

Times may follow dates with a colon, e.g.  ‘1965/07/12:09:45’; this is
in order to provide a format with no whitespace.  A comma and whitespace
are allowed, e.g.  ‘1965/07/12, 09:45’.  Currently the order of these
separators is not checked, so illogical formats such as ‘1965/07/12, :
,09:45’ will also be matched.  For simplicity such variations are not
shown in the list above.  Otherwise, a time is only recognised as being
associated with a date if there is only whitespace in between, or if the
time was embedded in the date.

Days of the week are not normally scanned, but will be ignored if they
occur at the start of the date pattern only.  However, in contexts where
it is useful to specify dates relative to today, days of the week with
no other date specification may be given.  The day is assumed to be
either today or within the past week.  Likewise, the words ‘yesterday’,
‘today’ and ‘tomorrow’ are handled.  All matches are case-insensitive.
Hence if today is Monday, then ‘Sunday’ is equivalent to ‘yesterday’,
‘Monday’ is equivalent to ‘today’, but ‘Tuesday’ gives a date six days
ago.  This is not generally useful within the calendar file.  Dates in
this format may be combined with a time specification; for example
‘Tomorrow, 8 p.m.’.

For example, the standard date format:

      Fri Aug 18 17:00:48 BST 2006

is handled by matching HH‘:’MM‘:’SS and removing it together with the
matched (but unused) time zone.  This leaves the following:

      Fri Aug 18 2006

‘Fri’ is ignored and the rest is matched according to the standard
rules.


File: zsh.info,  Node: Relative Time Format,  Next: Example<3>,  Prev: Date Format,  Up: File and Date Formats

22.2.3 Relative Time Format
---------------------------

In certain places relative times are handled.  Here, a date is not
allowed; instead a combination of various supported periods are allowed,
together with an optional time.  The periods must be in order from most
to least significant.

In some cases, a more accurate calculation is possible when there is an
anchor date: offsets of months or years pick the correct day, rather
than being rounded, and it is possible to pick a particular day in a
month as ‘(1st Friday)’, etc., as described in more detail below.

Anchors are available in the following cases.  If one or two times are
passed to the function ‘calendar’, the start time acts an anchor for the
end time when the end time is relative (even if the start time is
implicit).  When examining calendar files, the scheduled event being
examined anchors the warning time when it is given explicitly by means
of the ‘WARN’ keyword; likewise, the scheduled event anchors a
repetition period when given by the ‘RPT’ keyword, so that
specifications such as ‘RPT 2 months, 3rd Thursday’ are handled
properly.  Finally, the ‘-R’ argument to ‘calendar_scandate’ directly
provides an anchor for relative calculations.

The periods handled, with possible abbreviations are:

Years

     ‘years’, ‘yrs’, ‘ys’, ‘year’, ‘yr’, ‘y’, ‘yearly’.  A year is
     365.25 days unless there is an anchor.

Months

     ‘months’, ‘mons’, ‘mnths’, ‘mths’, ‘month’, ‘mon’, ‘mnth’, ‘mth’,
     ‘monthly’.  Note that ‘m’, ‘ms’, ‘mn’, ‘mns’ are ambiguous and are
     ‘not’ handled.  A month is a period of 30 days rather than a
     calendar month unless there is an anchor.

Weeks

     ‘weeks’, ‘wks’, ‘ws’, ‘week’, ‘wk’, ‘w’, ‘weekly’

Days

     ‘days’, ‘dys’, ‘ds’, ‘day’, ‘dy’, ‘d’, ‘daily’

Hours

     ‘hours’, ‘hrs’, ‘hs’, ‘hour’, ‘hr’, ‘h’, ‘hourly’

Minutes

     ‘minutes’, ‘mins’, ‘minute’, ‘min’, but ‘not’ ‘m’, ‘ms’, ‘mn’ or
     ‘mns’

Seconds

     ‘seconds’, ‘secs’, ‘ss’, ‘second’, ‘sec’, ‘s’

Spaces between the numbers are optional, but are required between items,
although a comma may be used (with or without spaces).

The forms ‘yearly’ to ‘hourly’ allow the number to be omitted; it is
assumed to be 1.  For example, ‘1 d’ and ‘daily’ are equivalent.  Note
that using those forms with plurals is confusing; ‘2 yearly’ is the same
as ‘2 years’, ‘not’ twice yearly, so it is recommended they only be used
without numbers.

When an anchor time is present, there is an extension to handle regular
events in the form of the Nth SOMEday of the month.  Such a
specification must occur immediately after any year and month
specification, but before any time of day, and must be in the form
N(‘th|st|rd’) DAY, for example ‘1st Tuesday’ or ‘3rd Monday’.  As in
other places, days are matched case insensitively, must be in English,
and only the first three letters are significant except that a form
beginning ‘month’ does not match ‘Monday’.  No attempt is made to
sanitize the resulting date; attempts to squeeze too many occurrences
into a month will push the day into the next month (but in the obvious
fashion, retaining the correct day of the week).

Here are some examples:

      30 years 3 months 4 days 3:42:41
      14 days 5 hours
      Monthly, 3rd Thursday
      4d,10hr


File: zsh.info,  Node: Example<3>,  Prev: Relative Time Format,  Up: File and Date Formats

22.2.4 Example
--------------

Here is an example calendar file.  It uses a consistent date format, as
recommended above.

      Feb 1, 2006 14:30 Pointless bureaucratic meeting
      Mar 27, 2006 11:00 Mutual recrimination and finger pointing
        Bring water pistol and waterproofs
      Mar 31, 2006 14:00 Very serious managerial pontification
        # UID 12C7878A9A50
      Apr 10, 2006 13:30 Even more pointless blame assignment exercise WARN 30 mins
      May 18, 2006 16:00 Regular moaning session RPT monthly, 3rd Thursday

The second entry has a continuation line.  The third entry has a
continuation line that will not be shown when the entry is displayed,
but the unique identifier will be used by the ‘calendar_add’ function
when updating the event.  The fourth entry will produce a warning 30
minutes before the event (to allow you to equip yourself appropriately).
The fifth entry repeats after a month on the 3rd Thursday, i.e.  June
15, 2006, at the same time.


File: zsh.info,  Node: User Functions,  Next: Styles,  Prev: File and Date Formats,  Up: Calendar Function System

22.3 User Functions
===================

This section describes functions that are designed to be called directly
by the user.  The first part describes those functions associated with
the user’s calendar; the second part describes the use in glob
qualifiers.

* Menu:

* Calendar System Functions::
* Glob Qualifiers: Glob Qualifiers<2>.


File: zsh.info,  Node: Calendar System Functions,  Next: Glob Qualifiers<2>,  Up: User Functions

22.3.1 Calendar System Functions
--------------------------------

‘calendar’ [ ‘-abdDsv’ ] [ ‘-C’ CALFILE ] [ ‘-n’ NUM ] [ ‘-S’ SHOWPROG ]

     [ [ START ] END ]

‘calendar -r’ [ ‘-abdDrsv’ ] [ ‘-C’ CALFILE ] [ ‘-n’ NUM ] [ ‘-S’
SHOWPROG ]

          [ START ]

     Show events in the calendar.

     With no arguments, show events from the start of today until the
     end of the next working day after today.  In other words, if today
     is Friday, Saturday, or Sunday, show up to the end of the following
     Monday, otherwise show today and tomorrow.

     If END is given, show events from the start of today up to the time
     and date given, which is in the format described in the previous
     section.  Note that if this is a date the time is assumed to be
     midnight at the start of the date, so that effectively this shows
     all events before the given date.

     END may start with a ‘+’, in which case the remainder of the
     specification is a relative time format as described in the
     previous section indicating the range of time from the start time
     that is to be included.

     If START is also given, show events starting from that time and
     date.  The word ‘now’ can be used to indicate the current time.

     To implement an alert when events are due, include ‘calendar -s’ in
     your ‘~/.zshrc’ file.

     Options:

     ‘-a’

          Show all items in the calendar, regardless of the ‘start’ and
          ‘end’.

     ‘-b’

          Brief: don’t display continuation lines (i.e.  indented lines
          following the line with the date/time), just the first line.

     ‘-B’ LINES

          Brief: display at most the first LINES lines of the calendar
          entry.  ‘-B 1’ is equivalent to ‘-b’.

     ‘-C’ CALFILE

          Explicitly specify a calendar file instead of the value of the
          ‘calendar-file’ style or the default ‘~/calendar’.

     ‘-d’

          Move any events that have passed from the calendar file to the
          “done” file, as given by the ‘done-file’ style or the default
          which is the calendar file with ‘.done’ appended.  This option
          is implied by the ‘-s’ option.

     ‘-D’

          Turns off the option ‘-d’, even if the ‘-s’ option is also
          present.

     ‘-n’ NUM, ‘-’NUM

          Show at least NUM events, if present in the calendar file,
          regardless of the ‘start’ and ‘end’.

     ‘-r’

          Show all the remaining options in the calendar, ignoring the
          given END time.  The START time is respected; any argument
          given is treated as a START time.

     ‘-s’

          Use the shell’s ‘sched’ command to schedule a timed event that
          will warn the user when an event is due.  Note that the
          ‘sched’ command only runs if the shell is at an interactive
          prompt; a foreground task blocks the scheduled task from
          running until it is finished.

          The timed event usually runs the programme ‘calendar_show’ to
          show the event, as described in *note Utility Functions: 172.

          By default, a warning of the event is shown five minutes
          before it is due.  The warning period can be configured by the
          style ‘warn-time’ or for a single calendar entry by including
          ‘WARN’ RELTIME in the first line of the entry, where RELTIME
          is one of the usual relative time formats.

          A repeated event may be indicated by including ‘RPT’ RELDATE
          in the first line of the entry.  After the scheduled event has
          been displayed it will be re-entered into the calendar file at
          a time RELDATE after the existing event.  Note that this is
          currently the only use made of the repeat count, so that it is
          not possible to query the schedule for a recurrence of an
          event in the calendar until the previous event has passed.

          If ‘RPT’ is used, it is also possible to specify that certain
          recurrences of an event are rescheduled or cancelled.  This is
          done with the ‘OCCURRENCE’ keyword, followed by whitespace and
          the date and time of the occurrence in the regular sequence,
          followed by whitespace and either the date and time of the
          rescheduled event or the exact string ‘CANCELLED’.  In this
          case the date and time must be in exactly the “date with local
          time” format used by the ‘text/calendar’ MIME type (RFC 2445),
          <YYYY><MM><DD>‘T’<HH><MM><SS> (note the presence of the
          literal character ‘T’).  The first word (the regular
          recurrence) may be something other than a proper date/time to
          indicate that the event is additional to the normal sequence;
          a convention that retains the formatting appearance is
          ‘XXXXXXXXTXXXXXX’.

          Furthermore, it is useful to record the next regular
          recurrence (as then the displayed date may be for a
          rescheduled event so cannot be used for calculating the
          regular sequence).  This is specified by ‘RECURRENCE’ and a
          time or date in the same format.  ‘calendar_add’ adds such an
          indication when it encounters a recurring event that does not
          include one, based on the headline date/time.

          If ‘calendar_add’ is used to update occurrences the ‘UID’
          keyword described there should be present in both the existing
          entry and the added occurrence in order to identify recurring
          event sequences.

          For example,

                Thu May 6, 2010 11:00 Informal chat RPT 1 week
                  # RECURRENCE 20100506T110000
                  # OCCURRENCE 20100513T110000 20100513T120000
                  # OCCURRENCE 20100520T110000 CANCELLED

          The event that occurs at 11:00 on 13th May 2010 is rescheduled
          an hour later.  The event that occurs a week later is
          cancelled.  The occurrences are given on a continuation line
          starting with a ‘#’ character so will not usually be displayed
          as part of the event.  As elsewhere, no account of time zones
          is taken with the times.  After the next event occurs the
          headline date/time will be ‘Thu May 13, 2010 12:00’ while the
          ‘RECURRENCE’ date/time will be ‘20100513T110000’ (note that
          cancelled and moved events are not taken account of in the
          ‘RECURRENCE’, which records what the next regular recurrence
          is, but they are accounted for in the headline date/time).

          It is safe to run ‘calendar -s’ to reschedule an existing
          event (if the calendar file has changed, for example), and
          also to have it running in multiples instances of the shell
          since the calendar file is locked when in use.

          By default, expired events are moved to the “done” file; see
          the ‘-d’ option.  Use ‘-D’ to prevent this.

     ‘-S’ SHOWPROG

          Explicitly specify a programme to be used for showing events
          instead of the value of the ‘show-prog’ style or the default
          ‘calendar_show’.

     ‘-v’

          Verbose: show more information about stages of processing.
          This is useful for confirming that the function has
          successfully parsed the dates in the calendar file.

‘calendar_add’ [ ‘-BL’ ] EVENT …

     Adds a single event to the calendar in the appropriate location.
     The event can contain multiple lines, as described in *note File
     and Date Formats: 169.  Using this function ensures that the
     calendar file is sorted in date and time order.  It also makes
     special arrangements for locking the file while it is altered.  The
     old calendar is left in a file with the suffix ‘.old’.

     The option ‘-B’ indicates that backing up the calendar file will be
     handled by the caller and should not be performed by
     ‘calendar_add’.  The option ‘-L’ indicates that ‘calendar_add’ does
     not need to lock the calendar file as it is already locked.  These
     options will not usually be needed by users.

     If the style ‘reformat-date’ is true, the date and time of the new
     entry will be rewritten into the standard date format: see the
     descriptions of this style and the style ‘date-format’.

     The function can use a unique identifier stored with each event to
     ensure that updates to existing events are treated correctly.  The
     entry should contain the word ‘UID’, followed by whitespace,
     followed by a word consisting entirely of hexadecimal digits of
     arbitrary length (all digits are significant, including leading
     zeroes).  As the UID is not directly useful to the user, it is
     convenient to hide it on an indented continuation line starting
     with a ‘#’, for example:

           Aug 31, 2007 09:30  Celebrate the end of the holidays
             # UID 045B78A0

     The second line will not be shown by the ‘calendar’ function.

     It is possible to specify the ‘RPT’ keyword followed by ‘CANCELLED’
     instead of a relative time.  This causes any matched event or
     series of events to be cancelled (the original event does not have
     to be marked as recurring in order to be cancelled by this method).
     A ‘UID’ is required in order to match an existing event in the
     calendar.

     ‘calendar_add’ will attempt to manage recurrences and occurrences
     of repeating events as described for event scheduling by ‘calendar
     -s’ above.  To reschedule or cancel a single event ‘calendar_add’
     should be called with an entry that includes the correct ‘UID’ but
     does ‘not’ include the ‘RPT’ keyword as this is taken to mean the
     entry applies to a series of repeating events and hence replaces
     all existing information.  Each rescheduled or cancelled occurrence
     must have an ‘OCCURRENCE’ keyword in the entry passed to
     ‘calendar_add’ which will be merged into the calendar file.  Any
     existing reference to the occurrence is replaced.  An occurrence
     that does not refer to a valid existing event is added as a one-off
     occurrence to the same calendar entry.

‘calendar_edit’

     This calls the user’s editor to edit the calendar file.  If there
     are arguments, they are taken as the editor to use (the file name
     is appended to the commands); otherwise, the editor is given by the
     variable ‘VISUAL’, if set, else the variable ‘EDITOR’.

     If the calendar scheduler was running, then after editing the file
     ‘calendar -s’ is called to update it.

     This function locks out the calendar system during the edit.  Hence
     it should be used to edit the calendar file if there is any
     possibility of a calendar event occurring meanwhile.  Note this can
     lead to another shell with calendar functions enabled hanging
     waiting for a lock, so it is necessary to quit the editor as soon
     as possible.

‘calendar_parse’ CALENDAR-ENTRY

     This is the internal function that analyses the parts of a calendar
     entry, which is passed as the only argument.  The function returns
     status 1 if the argument could not be parsed as a calendar entry
     and status 2 if the wrong number of arguments were passed; it also
     sets the parameter ‘reply’ to an empty associative array.
     Otherwise, it returns status 0 and sets elements of the associative
     array ‘reply’ as follows:

     ‘time’

          The time as a string of digits in the same units as
          ‘$EPOCHSECONDS’

     ‘schedtime’

          The regularly scheduled time.  This may differ from the actual
          event time ‘time’ if this is a recurring event and the next
          occurrence has been rescheduled.  Then ‘time’ gives the actual
          time and ‘schedtime’ the time of the regular recurrence before
          modification.

     ‘text1’

          The text from the line not including the date and time of the
          event, but including any ‘WARN’ or ‘RPT’ keywords and values.

     ‘warntime’

          Any warning time given by the ‘WARN’ keyword as a string of
          digits containing the time at which to warn in the same units
          as ‘$EPOCHSECONDS’.  (Note this is an absolute time, not the
          relative time passed down.)  Not set no ‘WARN’ keyword and
          value were matched.

     ‘warnstr’

          The raw string matched after the ‘WARN’ keyword, else unset.

     ‘rpttime’

          Any recurrence time given by the ‘RPT’ keyword as a string of
          digits containing the time of the recurrence in the same units
          as ‘$EPOCHSECONDS’.  (Note this is an absolute time.)  Not set
          if no ‘RPT’ keyword and value were matched.

     ‘schedrpttime’

          The next regularly scheduled occurrence of a recurring event
          before modification.  This may differ from ‘rpttime’, which is
          the actual time of the event that may have been rescheduled
          from the regular time.

     ‘rptstr’

          The raw string matched after the ‘RPT’ keyword, else unset.

     ‘text2’

          The text from the line after removal of the date and any
          keywords and values.

‘calendar_showdate’ [ ‘-r’ ] [ ‘-f’ FMT ] DATE-SPEC …

     The given DATE-SPEC is interpreted and the corresponding date and
     time printed.  If the initial DATE-SPEC begins with a ‘+’ or ‘-’ it
     is treated as relative to the current time; DATE-SPECs after the
     first are treated as relative to the date calculated so far and a
     leading ‘+’ is optional in that case.  This allows one to use the
     system as a date calculator.  For example, ‘calendar_showdate '+1
     month, 1st Friday'’ shows the date of the first Friday of next
     month.

     With the option ‘-r’ nothing is printed but the value of the date
     and time in seconds since the epoch is stored in the parameter
     ‘REPLY’.

     With the option ‘-f’ FMT the given date/time conversion format is
     passed to ‘strftime’; see notes on the ‘date-format’ style below.

     In order to avoid ambiguity with negative relative date
     specifications, options must occur in separate words; in other
     words, ‘-r’ and ‘-f’ should not be combined in the same word.

‘calendar_sort’

     Sorts the calendar file into date and time order.  The old calendar
     is left in a file with the suffix ‘.old’.


File: zsh.info,  Node: Glob Qualifiers<2>,  Prev: Calendar System Functions,  Up: User Functions

22.3.2 Glob Qualifiers
----------------------

‘age’

     The function ‘age’ can be autoloaded and use separately from the
     calendar system, although it uses the function ‘calendar_scandate’
     for date formatting.  It requires the ‘zsh/stat’ builtin, but uses
     only the builtin ‘zstat’.

     ‘age’ selects files having a given modification time for use as a
     glob qualifier.  The format of the date is the same as that
     understood by the calendar system, described in *note File and Date
     Formats: 169.

     The function can take one or two arguments, which can be supplied
     either directly as command or arguments, or separately as shell
     parameters.

           print *(e:age 2006/10/04 2006/10/09:)

     The example above matches all files modified between the start of
     those dates.  The second argument may alternatively be a relative
     time introduced by a ‘+’:

           print *(e:age 2006/10/04 +5d:)

     The example above is equivalent to the previous example.

     In addition to the special use of days of the week, ‘today’ and
     ‘yesterday’, times with no date may be specified; these apply to
     today.  Obviously such uses become problematic around midnight.

           print *(e-age 12:00 13:30-)

     The example above shows files modified between 12:00 and 13:00
     today.

           print *(e:age 2006/10/04:)

     The example above matches all files modified on that date.  If the
     second argument is omitted it is taken to be exactly 24 hours after
     the first argument (even if the first argument contains a time).

           print *(e-age 2006/10/04:10:15 2006/10/04:10:45-)

     The example above supplies times.  Note that whitespace within the
     time and date specification must be quoted to ensure ‘age’ receives
     the correct arguments, hence the use of the additional colon to
     separate the date and time.

           AGEREF=2006/10/04:10:15
           AGEREF2=2006/10/04:10:45
           print *(+age)

     This shows the same example before using another form of argument
     passing.  The dates and times in the parameters ‘AGEREF’ and
     ‘AGEREF2’ stay in effect until unset, but will be overridden if any
     argument is passed as an explicit argument to age.  Any explicit
     argument causes both parameters to be ignored.

     Instead of an explicit date and time, it’s possible to use the
     modification time of a file as the date and time for either
     argument by introducing the file name with a colon:

           print *(e-age :file1-)

     matches all files created on the same day (24 hours starting from
     midnight) as ‘file1’.

           print *(e-age :file1 :file2-)

     matches all files modified no earlier than ‘file1’ and no later
     than ‘file2’; precision here is to the nearest second.

‘after’

‘before’

     The functions ‘after’ and ‘before’ are simpler versions of ‘age’
     that take just one argument.  The argument is parsed similarly to
     an argument of ‘age’; if it is not given the variable ‘AGEREF’ is
     consulted.  As the names of the functions suggest, a file matches
     if its modification time is after or before the time and date
     specified.  If a time only is given the date is today.

     The two following examples are therefore equivalent:

           print *(e-after 12:00-)
           print *(e-after today:12:00-)


File: zsh.info,  Node: Styles,  Next: Utility functions,  Prev: User Functions,  Up: Calendar Function System

22.4 Styles
===========

The zsh style mechanism using the ‘zstyle’ command is describe in *note
The zsh/zutil Module: ca.  This is the same mechanism used in the
completion system.

The styles below are all examined in the context
‘:datetime:’FUNCTION‘:’, for example ‘:datetime:calendar:’.

‘calendar-file’

     The location of the main calendar.  The default is ‘~/calendar’.

‘date-format’

     A ‘strftime’ format string (see ‘strftime(3)’) with the zsh
     extensions providing various numbers with no leading zero or space
     if the number is a single digit as described for the ‘%D{’STRING‘}’
     prompt format in *note Simple Prompt Escapes: 175.

     This is used for outputting dates in ‘calendar’, both to support
     the ‘-v’ option and when adding recurring events back to the
     calendar file, and in ‘calendar_showdate’ as the final output
     format.

     If the style is not set, the default used is similar the standard
     system format as output by the ‘date’ command (also known as ‘ctime
     format’): ‘%a %b %d %H:%M:%S %Z %Y’.

‘done-file’

     The location of the file to which events which have passed are
     appended.  The default is the calendar file location with the
     suffix ‘.done’.  The style may be set to an empty string in which
     case a “done” file will not be maintained.

‘reformat-date’

     Boolean, used by ‘calendar_add’.  If it is true, the date and time
     of new entries added to the calendar will be reformatted to the
     format given by the style ‘date-format’ or its default.  Only the
     date and time of the event itself is reformatted; any subsidiary
     dates and times such as those associated with repeat and warning
     times are left alone.

‘show-prog’

     The programme run by ‘calendar’ for showing events.  It will be
     passed the start time and stop time of the events requested in
     seconds since the epoch followed by the event text.  Note that
     ‘calendar -s’ uses a start time and stop time equal to one another
     to indicate alerts for specific events.

     The default is the function ‘calendar_show’.

‘warn-time’

     The time before an event at which a warning will be displayed, if
     the first line of the event does not include the text ‘EVENT’
     RELTIME.  The default is 5 minutes.


File: zsh.info,  Node: Utility functions,  Next: Bugs,  Prev: Styles,  Up: Calendar Function System

22.5 Utility functions
======================

‘calendar_lockfiles’

     Attempt to lock the files given in the argument.  To prevent
     problems with network file locking this is done in an ad hoc
     fashion by attempting to create a symbolic link to the file with
     the name FILE‘.lockfile’.  No other system level functions are used
     for locking, i.e.  the file can be accessed and modified by any
     utility that does not use this mechanism.  In particular, the user
     is not prevented from editing the calendar file at the same time
     unless ‘calendar_edit’ is used.

     Three attempts are made to lock the file before giving up.  If the
     module ‘zsh/zselect’ is available, the times of the attempts are
     jittered so that multiple instances of the calling function are
     unlikely to retry at the same time.

     The files locked are appended to the array ‘lockfiles’, which
     should be local to the caller.

     If all files were successfully locked, status zero is returned,
     else status one.

     This function may be used as a general file locking function,
     although this will only work if only this mechanism is used to lock
     files.

‘calendar_read’

     This is a backend used by various other functions to parse the
     calendar file, which is passed as the only argument.  The array
     ‘calendar_entries’ is set to the list of events in the file; no
     pruning is done except that ampersands are removed from the start
     of the line.  Each entry may contain multiple lines.

‘calendar_scandate’

     This is a generic function to parse dates and times that may be
     used separately from the calendar system.  The argument is a date
     or time specification as described in *note File and Date Formats:
     169.  The parameter ‘REPLY’ is set to the number of seconds since
     the epoch corresponding to that date or time.  By default, the date
     and time may occur anywhere within the given argument.

     Returns status zero if the date and time were successfully parsed,
     else one.

     Options:

     ‘-a’

          The date and time are anchored to the start of the argument;
          they will not be matched if there is preceding text.

     ‘-A’

          The date and time are anchored to both the start and end of
          the argument; they will not be matched if the is any other
          text in the argument.

     ‘-d’

          Enable additional debugging output.

     ‘-m’

          Minus.  When ‘-R’ ANCHOR_TIME is also given the relative time
          is calculated backwards from ANCHOR_TIME.

     ‘-r’

          The argument passed is to be parsed as a relative time.

     ‘-R’ ANCHOR_TIME

          The argument passed is to be parsed as a relative time.  The
          time is relative to ANCHOR_TIME, a time in seconds since the
          epoch, and the returned value is the absolute time
          corresponding to advancing ANCHOR_TIME by the relative time
          given.  This allows lengths of months to be correctly taken
          into account.  If the final day does not exist in the given
          month, the last day of the final month is given.  For example,
          if the anchor time is during 31st January 2007 and the
          relative time is 1 month, the final time is the same time of
          day during 28th February 2007.

     ‘-s’

          In addition to setting ‘REPLY’, set ‘REPLY2’ to the remainder
          of the argument after the date and time have been stripped.
          This is empty if the option ‘-A’ was given.

     ‘-t’

          Allow a time with no date specification.  The date is assumed
          to be today.  The behaviour is unspecified if the iron tongue
          of midnight is tolling twelve.

‘calendar_show’

     The function used by default to display events.  It accepts a start
     time and end time for events, both in epoch seconds, and an event
     description.

     The event is always printed to standard output.  If the command
     line editor is active (which will usually be the case) the command
     line will be redisplayed after the output.

     If the parameter ‘DISPLAY’ is set and the start and end times are
     the same (indicating a scheduled event), the function uses the
     command ‘xmessage’ to display a window with the event details.


File: zsh.info,  Node: Bugs,  Prev: Utility functions,  Up: Calendar Function System

22.6 Bugs
=========

As the system is based entirely on shell functions (with a little
support from the ‘zsh/datetime’ module) the mechanisms used are not as
robust as those provided by a dedicated calendar utility.  Consequently
the user should not rely on the shell for vital alerts.

There is no ‘calendar_delete’ function.

There is no localization support for dates and times, nor any support
for the use of time zones.

Relative periods of months and years do not take into account the
variable number of days.

The ‘calendar_show’ function is currently hardwired to use ‘xmessage’
for displaying alerts on X Window System displays.  This should be
configurable and ideally integrate better with the desktop.

‘calendar_lockfiles’ hangs the shell while waiting for a lock on a file.
If called from a scheduled task, it should instead reschedule the event
that caused it.


File: zsh.info,  Node: TCP Function System,  Next: Zftp Function System,  Prev: Calendar Function System,  Up: Top

23 TCP Function System
**********************

* Menu:

* Description: Description<8>.
* TCP User Functions::
* TCP User-defined Functions::
* TCP Utility Functions::
* TCP User Parameters::
* TCP User-defined Parameters::
* TCP Utility Parameters::
* TCP Examples::
* TCP Bugs::


File: zsh.info,  Node: Description<8>,  Next: TCP User Functions,  Up: TCP Function System

23.1 Description
================

A module ‘zsh/net/tcp’ is provided to provide network I/O over TCP/IP
from within the shell; see its description in *note The zsh/net/tcp
Module: cf.  This manual page describes a function suite based on the
module.  If the module is installed, the functions are usually installed
at the same time, in which case they will be available for autoloading
in the default function search path.  In addition to the ‘zsh/net/tcp’
module, the ‘zsh/zselect’ module is used to implement timeouts on read
operations.  For troubleshooting tips, consult the corresponding advice
for the ‘zftp’ functions described in ‘zshzftpsys’.

There are functions corresponding to the basic I/O operations open,
close, read and send, named ‘tcp_open’ etc., as well as a function
‘tcp_expect’ for pattern match analysis of data read as input.  The
system makes it easy to receive data from and send data to multiple
named sessions at once.  In addition, it can be linked with the shell’s
line editor in such a way that input data is automatically shown at the
terminal.  Other facilities available including logging, filtering and
configurable output prompts.

To use the system where it is available, it should be enough to
‘autoload -U tcp_open’ and run ‘tcp_open’ as documented below to start a
session.  The ‘tcp_open’ function will autoload the remaining functions.


File: zsh.info,  Node: TCP User Functions,  Next: TCP User-defined Functions,  Prev: Description<8>,  Up: TCP Function System

23.2 TCP User Functions
=======================

* Menu:

* Basic I/O::
* Session Management::
* Advanced I/O::
* `One-shot’ File Transfer::


File: zsh.info,  Node: Basic I/O,  Next: Session Management,  Up: TCP User Functions

23.2.1 Basic I/O
----------------

‘tcp_open’ [ ‘-qz’ ] HOST PORT [ SESS ]

‘tcp_open’ [ ‘-qz’ ] [ ‘-s’ SESS | ‘-l’ SESS[‘,’…] ] …

‘tcp_open’ [ ‘-qz’ ] [ ‘-a’ FD | ‘-f’ FD ] [ SESS ]

     Open a new session.  In the first and simplest form, open a TCP
     connection to host HOST at port PORT; numeric and symbolic forms
     are understood for both.

     If SESS is given, this becomes the name of the session which can be
     used to refer to multiple different TCP connections.  If SESS is
     not given, the function will invent a numeric name value (note this
     is ‘not’ the same as the file descriptor to which the session is
     attached).  It is recommended that session names not include
     ‘funny’ characters, where funny characters are not well-defined but
     certainly do not include alphanumerics or underscores, and
     certainly do include whitespace.

     In the second case, one or more sessions to be opened are given by
     name.  A single session name is given after ‘-s’ and a
     comma-separated list after ‘-l’; both options may be repeated as
     many times as necessary.  A failure to open any session causes
     ‘tcp_open’ to abort.  The host and port are read from the file
     ‘.ztcp_sessions’ in the same directory as the user’s zsh
     initialisation files, i.e.  usually the home directory, but
     ‘$ZDOTDIR’ if that is set.  The file consists of lines each giving
     a session name and the corresponding host and port, in that order
     (note the session name comes first, not last), separated by
     whitespace.

     The third form allows passive and fake TCP connections.  If the
     option ‘-a’ is used, its argument is a file descriptor open for
     listening for connections.  No function front-end is provided to
     open such a file descriptor, but a call to ‘ztcp -l’ PORT will
     create one with the file descriptor stored in the parameter
     ‘$REPLY’.  The listening port can be closed with ‘ztcp -c’ FD.  A
     call to ‘tcp_open -a’ FD will block until a remote TCP connection
     is made to PORT on the local machine.  At this point, a session is
     created in the usual way and is largely indistinguishable from an
     active connection created with one of the first two forms.

     If the option ‘-f’ is used, its argument is a file descriptor which
     is used directly as if it were a TCP session.  How well the
     remainder of the TCP function system copes with this depends on
     what actually underlies this file descriptor.  A regular file is
     likely to be unusable; a FIFO (pipe) of some sort will work better,
     but note that it is not a good idea for two different sessions to
     attempt to read from the same FIFO at once.

     If the option ‘-q’ is given with any of the three forms, ‘tcp_open’
     will not print informational messages, although it will in any case
     exit with an appropriate status.

     If the line editor (zle) is in use, which is typically the case if
     the shell is interactive, ‘tcp_open’ installs a handler inside zle
     which will check for new data at the same time as it checks for
     keyboard input.  This is convenient as the shell consumes no CPU
     time while waiting; the test is performed by the operating system.
     Giving the option ‘-z’ to any of the forms of ‘tcp_open’ prevents
     the handler from being installed, so data must be read explicitly.
     Note, however, this is not necessary for executing complete sets of
     send and read commands from a function, as zle is not active at
     this point.  Generally speaking, the handler is only active when
     the shell is waiting for input at a command prompt or in the
     ‘vared’ builtin.  The option has no effect if zle is not active;
     ‘[[ -o zle]]’ will test for this.

     The first session to be opened becomes the current session and
     subsequent calls to ‘tcp_open’ do not change it.  The current
     session is stored in the parameter ‘$TCP_SESS’; see below for more
     detail about the parameters used by the system.

     The function ‘tcp_on_open’, if defined, is called when a session is
     opened.  See the description below.

‘tcp_close’ [ ‘-qn’ ] [ ‘-a’ | ‘-l’ SESS[‘,’…] | SESS … ]

     Close the named sessions, or the current session if none is given,
     or all open sessions if ‘-a’ is given.  The options ‘-l’ and ‘-s’
     are both handled for consistency with ‘tcp_open’, although the
     latter is redundant.

     If the session being closed is the current one, ‘$TCP_SESS’ is
     unset, leaving no current session, even if there are other sessions
     still open.

     If the session was opened with ‘tcp_open -f’, the file descriptor
     is closed so long as it is in the range 0 to 9 accessible directly
     from the command line.  If the option ‘-n’ is given, no attempt
     will be made to close file descriptors in this case.  The ‘-n’
     option is not used for genuine ‘ztcp’ session; the file descriptors
     are always closed with the session.

     If the option ‘-q’ is given, no informational messages will be
     printed.

‘tcp_read’ [ ‘-bdq’ ] [ ‘-t’ TO ] [ ‘-T’ TO ]

          [ ‘-a’ | ‘-u’ FD[‘,’…] | ‘-l’ SESS[‘,’…] | ‘-s’ SESS … ]

     Perform a read operation on the current session, or on a list of
     sessions if any are given with ‘-u’, ‘-l’ or ‘-s’, or all open
     sessions if the option ‘-a’ is given.  Any of the ‘-u’, ‘-l’ or
     ‘-s’ options may be repeated or mixed together.  The ‘-u’ option
     specifies a file descriptor directly (only those managed by this
     system are useful), the other two specify sessions as described for
     ‘tcp_open’ above.

     The function checks for new data available on all the sessions
     listed.  Unless the ‘-b’ option is given, it will not block waiting
     for new data.  Any one line of data from any of the available
     sessions will be read, stored in the parameter ‘$TCP_LINE’, and
     displayed to standard output unless ‘$TCP_SILENT’ contains a
     non-empty string.  When printed to standard output the string
     ‘$TCP_PROMPT’ will be shown at the start of the line; the default
     form for this includes the name of the session being read.  See
     below for more information on these parameters.  In this mode,
     ‘tcp_read’ can be called repeatedly until it returns status 2 which
     indicates all pending input from all specified sessions has been
     handled.

     With the option ‘-b’, equivalent to an infinite timeout, the
     function will block until a line is available to read from one of
     the specified sessions.  However, only a single line is returned.

     The option ‘-d’ indicates that all pending input should be drained.
     In this case ‘tcp_read’ may process multiple lines in the manner
     given above; only the last is stored in ‘$TCP_LINE’, but the
     complete set is stored in the array ‘$tcp_lines’.  This is cleared
     at the start of each call to ‘tcp_read’.

     The options ‘-t’ and ‘-T’ specify a timeout in seconds, which may
     be a floating point number for increased accuracy.  With ‘-t’ the
     timeout is applied before each line read.  With ‘-T’, the timeout
     applies to the overall operation, possibly including multiple read
     operations if the option ‘-d’ is present; without this option,
     there is no distinction between ‘-t’ and ‘-T’.

     The function does not print informational messages, but if the
     option ‘-q’ is given, no error message is printed for a
     non-existent session.

     A return status of 2 indicates a timeout or no data to read.  Any
     other non-zero return status indicates some error condition.

     See ‘tcp_log’ for how to control where data is sent by ‘tcp_read’.

‘tcp_send’ [ ‘-cnq’ ] [ ‘-s’ SESS | ‘-l’ SESS[‘,’…] ] DATA …

‘tcp_send’ [ ‘-cnq’ ] ‘-a’ DATA …

     Send the supplied data strings to all the specified sessions in
     turn.  The underlying operation differs little from a ‘print -r’ to
     the session’s file descriptor, although it attempts to prevent the
     shell from dying owing to a ‘SIGPIPE’ caused by an attempt to write
     to a defunct session.

     The option ‘-c’ causes ‘tcp_send’ to behave like ‘cat’.  It reads
     lines from standard input until end of input and sends them in turn
     to the specified session(s) exactly as if they were given as DATA
     arguments to individual ‘tcp_send’ commands.

     The option ‘-n’ prevents ‘tcp_send’ from putting a newline at the
     end of the data strings.

     The remaining options all behave as for ‘tcp_read’.

     The data arguments are not further processed once they have been
     passed to ‘tcp_send’; they are simply passed down to ‘print -r’.

     If the parameter ‘$TCP_OUTPUT’ is a non-empty string and logging is
     enabled then the data sent to each session will be echoed to the
     log file(s) with ‘$TCP_OUTPUT’ in front where appropriate, much in
     the manner of ‘$TCP_PROMPT’.


File: zsh.info,  Node: Session Management,  Next: Advanced I/O,  Prev: Basic I/O,  Up: TCP User Functions

23.2.2 Session Management
-------------------------

‘tcp_alias’ [ ‘-q’ ] ALIAS‘=’SESS …

‘tcp_alias’ [ ‘-q’ ] [ ALIAS … ]

‘tcp_alias’ ‘-d’ [ ‘-q’ ] ALIAS …

     This function is not particularly well tested.

     The first form creates an alias for a session name; ALIAS can then
     be used to refer to the existing session SESS.  As many aliases may
     be listed as required.

     The second form lists any aliases specified, or all aliases if
     none.

     The third form deletes all the aliases listed.  The underlying
     sessions are not affected.

     The option ‘-q’ suppresses an inconsistently chosen subset of error
     messages.

‘tcp_log’ [ ‘-asc’ ] [ ‘-n’ | ‘-N’ ] [ LOGFILE ]

     With an argument LOGFILE, all future input from ‘tcp_read’ will be
     logged to the named file.  Unless ‘-a’ (append) is given, this file
     will first be truncated or created empty.  With no arguments, show
     the current status of logging.

     With the option ‘-s’, per-session logging is enabled.  Input from
     ‘tcp_read’ is output to the file LOGFILE‘.’SESS.  As the session is
     automatically discriminated by the filename, the contents are raw
     (no ‘$TCP_PROMPT’).  The option ‘-a’ applies as above.  Per-session
     logging and logging of all data in one file are not mutually
     exclusive.

     The option ‘-c’ closes all logging, both complete and per-session
     logs.

     The options ‘-n’ and ‘-N’ respectively turn off or restore output
     of data read by ‘tcp_read’ to standard output; hence ‘tcp_log -cn’
     turns off all output by ‘tcp_read’.

     The function is purely a convenient front end to setting the
     parameters ‘$TCP_LOG’, ‘$TCP_LOG_SESS’, ‘$TCP_SILENT’, which are
     described below.

‘tcp_rename’ OLD NEW

     Rename session OLD to session NEW.  The old name becomes invalid.

‘tcp_sess’ [ SESS [ COMMAND [ ARG … ] ] ]

     With no arguments, list all the open sessions and associated file
     descriptors.  The current session is marked with a star.  For use
     in functions, direct access to the parameters ‘$tcp_by_name’,
     ‘$tcp_by_fd’ and ‘$TCP_SESS’ is probably more convenient; see
     below.

     With a SESS argument, set the current session to SESS.  This is
     equivalent to changing ‘$TCP_SESS’ directly.

     With additional arguments, temporarily set the current session
     while executing COMMAND ARG ….  COMMAND is re-evaluated so as to
     expand aliases etc., but the remaining ARGs are passed through as
     that appear to ‘tcp_sess’.  The original session is restored when
     ‘tcp_sess’ exits.


File: zsh.info,  Node: Advanced I/O,  Next: `One-shot’ File Transfer,  Prev: Session Management,  Up: TCP User Functions

23.2.3 Advanced I/O
-------------------

‘tcp_command’ SEND-OPTION … SEND-ARGUMENT …

     This is a convenient front-end to ‘tcp_send’.  All arguments are
     passed to ‘tcp_send’, then the function pauses waiting for data.
     While data is arriving at least every ‘$TCP_TIMEOUT’ (default 0.3)
     seconds, data is handled and printed out according to the current
     settings.  Status 0 is always returned.

     This is generally only useful for interactive use, to prevent the
     display becoming fragmented by output returned from the connection.
     Within a programme or function it is generally better to handle
     reading data by a more explicit method.

‘tcp_expect’ [ ‘-q’ ] [ ‘-p’ VAR | ‘-P’ VAR ] [ ‘-t’ TO | ‘-T’ TO ]

          [ ‘-a’ | ‘-s’ SESS | ‘-l’ SESS[‘,’…] ] PATTERN …

     Wait for input matching any of the given PATTERNs from any of the
     specified sessions.  Input is ignored until an input line matches
     one of the given patterns; at this point status zero is returned,
     the matching line is stored in ‘$TCP_LINE’, and the full set of
     lines read during the call to ‘tcp_expect’ is stored in the array
     ‘$tcp_expect_lines’.

     Sessions are specified in the same way as ‘tcp_read’: the default
     is to use the current session, otherwise the sessions specified by
     ‘-a’, ‘-s’, or ‘-l’ are used.

     Each PATTERN is a standard zsh extended-globbing pattern; note that
     it needs to be quoted to avoid it being expanded immediately by
     filename generation.  It must match the full line, so to match a
     substring there must be a ‘*’ at the start and end.  The line
     matched against includes the ‘$TCP_PROMPT’ added by ‘tcp_read’.  It
     is possible to include the globbing flags ‘#b’ or ‘#m’ in the
     patterns to make backreferences available in the parameters
     ‘$MATCH’, ‘$match’, etc., as described in the base zsh
     documentation on pattern matching.

     Unlike ‘tcp_read’, the default behaviour of ‘tcp_expect’ is to
     block indefinitely until the required input is found.  This can be
     modified by specifying a timeout with ‘-t’ or ‘-T’; these function
     as in ‘tcp_read’, specifying a per-read or overall timeout,
     respectively, in seconds, as an integer or floating-point number.
     As ‘tcp_read’, the function returns status 2 if a timeout occurs.

     The function returns as soon as any one of the patterns given
     match.  If the caller needs to know which of the patterns matched,
     the option ‘-p’ VAR can be used; on return, ‘$var’ is set to the
     number of the pattern using ordinary zsh indexing, i.e.  the first
     is 1, and so on.  Note the absence of a ‘$’ in front of VAR.  To
     avoid clashes, the parameter cannot begin with ‘_expect’.  The
     index -1 is used if there is a timeout and 0 if there is no match.

     The option ‘-P’ VAR works similarly to ‘-p’, but instead of
     numerical indexes the regular arguments must begin with a prefix
     followed by a colon: that prefix is then used as a tag to which VAR
     is set when the argument matches.  The tag ‘timeout’ is used if
     there is a timeout and the empty string if there is no match.  Note
     it is acceptable for different arguments to start with the same
     prefix if the matches do not need to be distinguished.

     The option ‘-q’ is passed directly down to ‘tcp_read’.

     As all input is done via ‘tcp_read’, all the usual rules about
     output of lines read apply.  One exception is that the parameter
     ‘$tcp_lines’ will only reflect the line actually matched by
     ‘tcp_expect’; use ‘$tcp_expect_lines’ for the full set of lines
     read during the function call.

‘tcp_proxy’

     This is a simple-minded function to accept a TCP connection and
     execute a command with I/O redirected to the connection.  Extreme
     caution should be taken as there is no security whatsoever and this
     can leave your computer open to the world.  Ideally, it should only
     be used behind a firewall.

     The first argument is a TCP port on which the function will listen.

     The remaining arguments give a command and its arguments to execute
     with standard input, standard output and standard error redirected
     to the file descriptor on which the TCP session has been accepted.
     If no command is given, a new zsh is started.  This gives everyone
     on your network direct access to your account, which in many cases
     will be a bad thing.

     The command is run in the background, so ‘tcp_proxy’ can then
     accept new connections.  It continues to accept new connections
     until interrupted.

‘tcp_spam’ [ ‘-ertv’ ] [ ‘-a’ | ‘-s’ SESS | ‘-l’ SESS[‘,’…] ] CMD [ ARG
… ]

     Execute CMD [ ARG … ] for each session in turn.  Note this executes
     the command and arguments; it does not send the command line as
     data unless the ‘-t’ (transmit) option is given.

     The sessions may be selected explicitly with the standard ‘-a’,
     ‘-s’ or ‘-l’ options, or may be chosen implicitly.  If none of the
     three options is given the rules are: first, if the array
     ‘$tcp_spam_list’ is set, this is taken as the list of sessions,
     otherwise all sessions are taken.  Second, any sessions given in
     the array ‘$tcp_no_spam_list’ are removed from the list of
     sessions.

     Normally, any sessions added by the ‘-a’ flag or when all sessions
     are chosen implicitly are spammed in alphabetic order; sessions
     given by the ‘$tcp_spam_list’ array or on the command line are
     spammed in the order given.  The ‘-r’ flag reverses the order
     however it was arrived it.

     The ‘-v’ flag specifies that a ‘$TCP_PROMPT’ will be output before
     each session.  This is output after any modification to ‘TCP_SESS’
     by the user-defined ‘tcp_on_spam’ function described below.
     (Obviously that function is able to generate its own output.)

     If the option ‘-e’ is present, the line given as CMD [ ARG … ] is
     executed using ‘eval’, otherwise it is executed without any further
     processing.

‘tcp_talk’

     This is a fairly simple-minded attempt to force input to the line
     editor to go straight to the default ‘TCP_SESS’.

     An escape string, ‘$TCP_TALK_ESCAPE’, default ‘:’, is used to allow
     access to normal shell operation.  If it is on its own at the start
     of the line, or followed only by whitespace, the line editor
     returns to normal operation.  Otherwise, the string and any
     following whitespace are skipped and the remainder of the line
     executed as shell input without any change of the line editor’s
     operating mode.

     The current implementation is somewhat deficient in terms of use of
     the command history.  For this reason, many users will prefer to
     use some form of alternative approach for sending data easily to
     the current session.  One simple approach is to alias some special
     character (such as ‘%’) to ‘tcp_command --’.

‘tcp_wait’

     The sole argument is an integer or floating point number which
     gives the seconds to delay.  The shell will do nothing for that
     period except wait for input on all TCP sessions by calling
     ‘tcp_read -a’.  This is similar to the interactive behaviour at the
     command prompt when zle handlers are installed.


File: zsh.info,  Node: `One-shot’ File Transfer,  Prev: Advanced I/O,  Up: TCP User Functions

23.2.4 ‘One-shot’ File Transfer
-------------------------------

‘tcp_point’ PORT

‘tcp_shoot’ HOST PORT

     This pair of functions provide a simple way to transfer a file
     between two hosts within the shell.  Note, however, that bulk data
     transfer is currently done using ‘cat’.  ‘tcp_point’ reads any data
     arriving at PORT and sends it to standard output; ‘tcp_shoot’
     connects to PORT on HOST and sends its standard input.  Any unused
     PORT may be used; the standard mechanism for picking a port is to
     think of a random four-digit number above 1024 until one works.

     To transfer a file from host ‘woodcock’ to host ‘springes’, on
     ‘springes’:

           tcp_point 8091 >output_file

     and on ‘woodcock’:

           tcp_shoot springes 8091 <input_file

     As these two functions do not require ‘tcp_open’ to set up a TCP
     connection first, they may need to be autoloaded separately.


File: zsh.info,  Node: TCP User-defined Functions,  Next: TCP Utility Functions,  Prev: TCP User Functions,  Up: TCP Function System

23.3 TCP User-defined Functions
===============================

Certain functions, if defined by the user, will be called by the
function system in certain contexts.  This facility depends on the
module ‘zsh/parameter’, which is usually available in interactive shells
as the completion system depends on it.  None of the functions need be
defined; they simply provide convenient hooks when necessary.

Typically, these are called after the requested action has been taken,
so that the various parameters will reflect the new state.

‘tcp_on_alias’ ALIAS FD

     When an alias is defined, this function will be called with two
     arguments: the name of the alias, and the file descriptor of the
     corresponding session.

‘tcp_on_awol’ SESS FD

     If the function ‘tcp_fd_handler’ is handling input from the line
     editor and detects that the file descriptor is no longer reusable,
     by default it removes it from the list of file descriptors handled
     by this method and prints a message.  If the function ‘tcp_on_awol’
     is defined it is called immediately before this point.  It may
     return status 100, which indicates that the normal handling should
     still be performed; any other return status indicates that no
     further action should be taken and the ‘tcp_fd_handler’ should
     return immediately with the given status.  Typically the action of
     ‘tcp_on_awol’ will be to close the session.

     The variable ‘TCP_INVALIDATE_ZLE’ will be a non-empty string if it
     is necessary to invalidate the line editor display using ‘zle -I’
     before printing output from the function.

     (‘AWOL’ is military jargon for ‘absent without leave’ or some
     variation.  It has no pre-existing technical meaning known to the
     author.)

‘tcp_on_close’ SESS FD

     This is called with the name of a session being closed and the file
     descriptor which corresponded to that session.  Both will be
     invalid by the time the function is called.

‘tcp_on_open’ SESS FD

     This is called after a new session has been defined with the
     session name and file descriptor as arguments.  If it returns a
     non-zero status, opening the session is assumed to fail and the
     session is closed again; however, ‘tcp_open’ will continue to
     attempt to open any remaining sessions given on the command line.

‘tcp_on_rename’ OLDSESS FD NEWSESS

     This is called after a session has been renamed with the three
     arguments old session name, file descriptor, new session name.

‘tcp_on_spam’ SESS COMMAND …

     This is called once for each session spammed, just ‘before’ a
     command is executed for a session by ‘tcp_spam’.  The arguments are
     the session name followed by the command list to be executed.  If
     ‘tcp_spam’ was called with the option ‘-t’, the first command will
     be ‘tcp_send’.

     This function is called after ‘$TCP_SESS’ is set to reflect the
     session to be spammed, but before any use of it is made.  Hence it
     is possible to alter the value of ‘$TCP_SESS’ within this function.
     For example, the session arguments to ‘tcp_spam’ could include
     extra information to be stripped off and processed in
     ‘tcp_on_spam’.

     If the function sets the parameter ‘$REPLY’ to ‘done’, the command
     line is not executed; in addition, no prompt is printed for the
     ‘-v’ option to ‘tcp_spam’.

‘tcp_on_unalias’ ALIAS FD

     This is called with the name of an alias and the corresponding
     session’s file descriptor after an alias has been deleted.


File: zsh.info,  Node: TCP Utility Functions,  Next: TCP User Parameters,  Prev: TCP User-defined Functions,  Up: TCP Function System

23.4 TCP Utility Functions
==========================

The following functions are used by the TCP function system but will
rarely if ever need to be called directly.

‘tcp_fd_handler’

     This is the function installed by ‘tcp_open’ for handling input
     from within the line editor, if that is required.  It is in the
     format documented for the builtin ‘zle -F’ in *note Zle Builtins:
     ba.

     While active, the function sets the parameter ‘TCP_HANDLER_ACTIVE’
     to 1.  This allows shell code called internally (for example, by
     setting ‘tcp_on_read’) to tell if is being called when the shell is
     otherwise idle at the editor prompt.

‘tcp_output’ [ ‘-q’ ] ‘-P’ PROMPT ‘-F’ FD ‘-S’ SESS

     This function is used for both logging and handling output to
     standard output, from within ‘tcp_read’ and (if ‘$TCP_OUTPUT’ is
     set) ‘tcp_send’.

     The PROMPT to use is specified by ‘-P’; the default is the empty
     string.  It can contain:

     ‘%c’

          Expands to 1 if the session is the current session, otherwise
          0.  Used with ternary expressions such as ‘%(c.-.+)’ to output
          ‘+’ for the current session and ‘-’ otherwise.

     ‘%f’

          Replaced by the session’s file descriptor.

     ‘%s’

          Replaced by the session name.

     ‘%%’

          Replaced by a single ‘%’.

     The option ‘-q’ suppresses output to standard output, but not to
     any log files which are configured.

     The ‘-S’ and ‘-F’ options are used to pass in the session name and
     file descriptor for possible replacement in the prompt.


File: zsh.info,  Node: TCP User Parameters,  Next: TCP User-defined Parameters,  Prev: TCP Utility Functions,  Up: TCP Function System

23.5 TCP User Parameters
========================

Parameters follow the usual convention that uppercase is used for
scalars and integers, while lowercase is used for normal and associative
array.  It is always safe for user code to read these parameters.  Some
parameters may also be set; these are noted explicitly.  Others are
included in this group as they are set by the function system for the
user’s benefit, i.e.  setting them is typically not useful but is
benign.

It is often also useful to make settable parameters local to a function.
For example, ‘local TCP_SILENT=1’ specifies that data read during the
function call will not be printed to standard output, regardless of the
setting outside the function.  Likewise, ‘local TCP_SESS=’SESS sets a
session for the duration of a function, and ‘local TCP_PROMPT=’
specifies that no prompt is used for input during the function.

‘tcp_expect_lines’

     Array.  The set of lines read during the last call to ‘tcp_expect’,
     including the last (‘$TCP_LINE’).

‘tcp_filter’

     Array.  May be set directly.  A set of extended globbing patterns
     which, if matched in ‘tcp_output’, will cause the line not to be
     printed to standard output.  The patterns should be defined as
     described for the arguments to ‘tcp_expect’.  Output of line to log
     files is not affected.

‘TCP_HANDLER_ACTIVE’

     Scalar.  Set to 1 within ‘tcp_fd_handler’ to indicate to functions
     called recursively that they have been called during an editor
     session.  Otherwise unset.

‘TCP_LINE’

     The last line read by ‘tcp_read’, and hence also ‘tcp_expect’.

‘TCP_LINE_FD’

     The file descriptor from which ‘$TCP_LINE’ was read.
     ‘${tcp_by_fd[$TCP_LINE_FD]}’ will give the corresponding session
     name.

‘tcp_lines’

     Array.  The set of lines read during the last call to ‘tcp_read’,
     including the last (‘$TCP_LINE’).

‘TCP_LOG’

     May be set directly, although it is also controlled by ‘tcp_log’.
     The name of a file to which output from all sessions will be sent.
     The output is proceeded by the usual ‘$TCP_PROMPT’.  If it is not
     an absolute path name, it will follow the user’s current directory.

‘TCP_LOG_SESS’

     May be set directly, although it is also controlled by ‘tcp_log’.
     The prefix for a set of files to which output from each session
     separately will be sent; the full filename is
     ‘${TCP_LOG_SESS}.’SESS.  Output to each file is raw; no prompt is
     added.  If it is not an absolute path name, it will follow the
     user’s current directory.

‘tcp_no_spam_list’

     Array.  May be set directly.  See ‘tcp_spam’ for how this is used.

‘TCP_OUTPUT’

     May be set directly.  If a non-empty string, any data sent to a
     session by ‘tcp_send’ will be logged.  This parameter gives the
     prompt to be used in a file specified by ‘$TCP_LOG’ but not in a
     file generated from ‘$TCP_LOG_SESS’.  The prompt string has the
     same format as ‘TCP_PROMPT’ and the same rules for its use apply.

‘TCP_PROMPT’

     May be set directly.  Used as the prefix for data read by
     ‘tcp_read’ which is printed to standard output or to the log file
     given by ‘$TCP_LOG’, if any.  Any ‘%s’, ‘%f’ or ‘%%’ occurring in
     the string will be replaced by the name of the session, the
     session’s underlying file descriptor, or a single ‘%’,
     respectively.  The expression ‘%c’ expands to 1 if the session
     being read is the current session, else 0; this is most useful in
     ternary expressions such as ‘%(c.-.+)’ which outputs ‘+’ if the
     session is the current one, else ‘-’.

     If the prompt starts with ‘%P’, this is stripped and the complete
     result of the previous stage is passed through standard prompt
     ‘%’-style formatting before being output.

‘TCP_READ_DEBUG’

     May be set directly.  If this has non-zero length, ‘tcp_read’ will
     give some limited diagnostics about data being read.

‘TCP_SECONDS_START’

     This value is created and initialised to zero by tcp_open.

     The functions ‘tcp_read’ and ‘tcp_expect’ use the shell’s ‘SECONDS’
     parameter for their own timing purposes.  If that parameter is not
     of floating point type on entry to one of the functions, it will
     create a local parameter ‘SECONDS’ which is floating point and set
     the parameter ‘TCP_SECONDS_START’ to the previous value of
     ‘$SECONDS’.  If the parameter is already floating point, it is used
     without a local copy being created and ‘TCP_SECONDS_START’ is not
     set.  As the global value is zero, the shell elapsed time is
     guaranteed to be the sum of ‘$SECONDS’ and ‘$TCP_SECONDS_START’.

     This can be avoided by setting ‘SECONDS’ globally to a floating
     point value using ‘typeset -F SECONDS’; then the TCP functions will
     never make a local copy and never set ‘TCP_SECONDS_START’ to a
     non-zero value.

‘TCP_SESS’

     May be set directly.  The current session; must refer to one of the
     sessions established by ‘tcp_open’.

‘TCP_SILENT’

     May be set directly, although it is also controlled by ‘tcp_log’.
     If of non-zero length, data read by ‘tcp_read’ will not be written
     to standard output, though may still be written to a log file.

‘tcp_spam_list’

     Array.  May be set directly.  See the description of the function
     ‘tcp_spam’ for how this is used.

‘TCP_TALK_ESCAPE’

     May be set directly.  See the description of the function
     ‘tcp_talk’ for how this is used.

‘TCP_TIMEOUT’

     May be set directly.  Currently this is only used by the function
     ‘tcp_command’, see above.


File: zsh.info,  Node: TCP User-defined Parameters,  Next: TCP Utility Parameters,  Prev: TCP User Parameters,  Up: TCP Function System

23.6 TCP User-defined Parameters
================================

The following parameters are not set by the function system, but have a
special effect if set by the user.

‘tcp_on_read’

     This should be an associative array; if it is not, the behaviour is
     undefined.  Each key is the name of a shell function or other
     command, and the corresponding value is a shell pattern (using
     ‘EXTENDED_GLOB’).  Every line read from a TCP session directly or
     indirectly using ‘tcp_read’ (which includes lines read by
     ‘tcp_expect’) is compared against the pattern.  If the line
     matches, the command given in the key is called with two arguments:
     the name of the session from which the line was read, and the line
     itself.

     If any function called to handle a line returns a non-zero status,
     the line is not output.  Thus a ‘tcp_on_read’ handler containing
     only the instruction ‘return 1’ can be used to suppress output of
     particular lines (see, however, ‘tcp_filter’ above).  However, the
     line is still stored in ‘TCP_LINE’ and ‘tcp_lines’; this occurs
     after all ‘tcp_on_read’ processing.


File: zsh.info,  Node: TCP Utility Parameters,  Next: TCP Examples,  Prev: TCP User-defined Parameters,  Up: TCP Function System

23.7 TCP Utility Parameters
===========================

These parameters are controlled by the function system; they may be read
directly, but should not usually be set by user code.

‘tcp_aliases’

     Associative array.  The keys are the names of sessions established
     with ‘tcp_open’; each value is a space-separated list of aliases
     which refer to that session.

‘tcp_by_fd’

     Associative array.  The keys are session file descriptors; each
     value is the name of that session.

‘tcp_by_name’

     Associative array.  The keys are the names of sessions; each value
     is the file descriptor associated with that session.


File: zsh.info,  Node: TCP Examples,  Next: TCP Bugs,  Prev: TCP Utility Parameters,  Up: TCP Function System

23.8 TCP Examples
=================

Here is a trivial example using a remote calculator.

To create a calculator server on port 7337 (see the ‘dc’ manual page for
quite how infuriating the underlying command is):

      tcp_proxy 7337 dc

To connect to this from the same host with a session also named ‘dc’:

      tcp_open localhost 7337 dc

To send a command to the remote session and wait a short while for
output (assuming ‘dc’ is the current session):

      tcp_command 2 4 + p

To close the session:

      tcp_close

The ‘tcp_proxy’ needs to be killed to be stopped.  Note this will not
usually kill any connections which have already been accepted, and also
that the port is not immediately available for reuse.

The following chunk of code puts a list of sessions into an xterm
header, with the current session followed by a star.

      print -n "\033]2;TCP:" ${(k)tcp_by_name:/$TCP_SESS/$TCP_SESS\*} "\a"


File: zsh.info,  Node: TCP Bugs,  Prev: TCP Examples,  Up: TCP Function System

23.9 TCP Bugs
=============

The function ‘tcp_read’ uses the shell’s normal ‘read’ builtin.  As this
reads a complete line at once, data arriving without a terminating
newline can cause the function to block indefinitely.

Though the function suite works well for interactive use and for data
arriving in small amounts, the performance when large amounts of data
are being exchanged is likely to be extremely poor.


File: zsh.info,  Node: Zftp Function System,  Next: User Contributions,  Prev: TCP Function System,  Up: Top

24 Zftp Function System
***********************

* Menu:

* Description: Description<9>.
* Installation::
* Functions: Functions<4>.
* Miscellaneous Features::


File: zsh.info,  Node: Description<9>,  Next: Installation,  Up: Zftp Function System

24.1 Description
================

This describes the set of shell functions supplied with the source
distribution as an interface to the ‘zftp’ builtin command, allowing you
to perform FTP operations from the shell command line or within
functions or scripts.  The interface is similar to a traditional FTP
client (e.g.  the ‘ftp’ command itself, see ‘ftp(1)’), but as it is
entirely done within the shell all the familiar completion, editing and
globbing features, and so on, are present, and macros are particularly
simple to write as they are just ordinary shell functions.

The prerequisite is that the ‘zftp’ command, as described in *note The
zsh/zftp Module: cb, must be available in the version of ‘zsh’ installed
at your site.  If the shell is configured to load new commands at run
time, it probably is: typing ‘zmodload zsh/zftp’ will make sure (if that
runs silently, it has worked).  If this is not the case, it is possible
‘zftp’ was linked into the shell anyway: to test this, type ‘which zftp’
and if ‘zftp’ is available you will get the message ‘zftp: shell
built-in command’.

Commands given directly with ‘zftp’ builtin may be interspersed between
the functions in this suite; in a few cases, using ‘zftp’ directly may
cause some of the status information stored in shell parameters to
become invalid.  Note in particular the description of the variables
‘$ZFTP_TMOUT’, ‘$ZFTP_PREFS’ and ‘$ZFTP_VERBOSE’ for ‘zftp’.


File: zsh.info,  Node: Installation,  Next: Functions<4>,  Prev: Description<9>,  Up: Zftp Function System

24.2 Installation
=================

You should make sure all the functions from the ‘Functions/Zftp’
directory of the source distribution are available; they all begin with
the two letters ‘zf’.  They may already have been installed on your
system; otherwise, you will need to find them and copy them.  The
directory should appear as one of the elements of the ‘$fpath’ array
(this should already be the case if they were installed), and at least
the function ‘zfinit’ should be autoloaded; it will autoload the rest.
Finally, to initialize the use of the system you need to call the
‘zfinit’ function.  The following code in your ‘.zshrc’ will arrange for
this; assume the functions are stored in the directory ‘~/myfns’:

      fpath=(~/myfns $fpath)
      autoload -U zfinit
      zfinit

Note that ‘zfinit’ assumes you are using the ‘zmodload’ method to load
the ‘zftp’ command.  If it is already built into the shell, change
‘zfinit’ to ‘zfinit -n’.  It is helpful (though not essential) if the
call to ‘zfinit’ appears after any code to initialize the new completion
system, else unnecessary ‘compctl’ commands will be given.


File: zsh.info,  Node: Functions<4>,  Next: Miscellaneous Features,  Prev: Installation,  Up: Zftp Function System

24.3 Functions
==============

The sequence of operations in performing a file transfer is essentially
the same as that in a standard FTP client.  Note that, due to a quirk of
the shell’s ‘getopts’ builtin, for those functions that handle options
you must use ‘--’ rather than ‘-’ to ensure the remaining arguments are
treated literally (a single ‘-’ is treated as an argument).

* Menu:

* Opening a Connection::
* Directory Management::
* Status Commands::
* Retrieving Files::
* Sending Files::
* Closing the Connection::
* Session Management: Session Management<2>.
* Bookmarks::
* Other Functions::


File: zsh.info,  Node: Opening a Connection,  Next: Directory Management,  Up: Functions<4>

24.3.1 Opening a Connection
---------------------------

‘zfparams’ [ HOST [ USER [ PASSWORD … ] ] ]

     Set or show the parameters for a future ‘zfopen’ with no arguments.
     If no arguments are given, the current parameters are displayed
     (the password will be shown as a line of asterisks).  If a HOST is
     given, and either the USER or PASSWORD is not, they will be
     prompted for; also, any parameter given as ‘?’ will be prompted
     for, and if the ‘?’ is followed by a string, that will be used as
     the prompt.  As ‘zfopen’ calls ‘zfparams’ to store the parameters,
     this usually need not be called directly.

     A single argument ‘-’ will delete the stored parameters.  This will
     also cause the memory of the last directory (and so on) on the
     other host to be deleted.

‘zfopen’ [ ‘-1’ ] [ HOST [ USER [ PASSWORD [ ACCOUNT ] ] ] ]

     If HOST is present, open a connection to that host under username
     USER with password PASSWORD (and, on the rare occasions when it is
     necessary, account ACCOUNT).  If a necessary parameter is missing
     or given as ‘?’ it will be prompted for.  If HOST is not present,
     use a previously stored set of parameters.

     If the command was successful, and the terminal is compatible with
     ‘xterm’ or is ‘sun-cmd’, a summary will appear in the title bar,
     giving the local ‘host:directory’ and the remote ‘host:directory’;
     this is handled by the function ‘zftp_chpwd’, described below.

     Normally, the HOST, USER and PASSWORD are internally recorded for
     later re-opening, either by a ‘zfopen’ with no arguments, or
     automatically (see below).  With the option ‘-1’, no information is
     stored.  Also, if an open command with arguments failed, the
     parameters will not be retained (and any previous parameters will
     also be deleted).  A ‘zfopen’ on its own, or a ‘zfopen -1’, never
     alters the stored parameters.

     Both ‘zfopen’ and ‘zfanon’ (but not ‘zfparams’) understand URLs of
     the form ‘ftp://’HOST/PATH… as meaning to connect to the HOST, then
     change directory to PATH (which must be a directory, not a file).
     The ‘ftp://’ can be omitted; the trailing ‘/’ is enough to trigger
     recognition of the PATH.  Note prefixes other than ‘ftp:’ are not
     recognized, and that all characters after the first slash beyond
     HOST are significant in PATH.

‘zfanon’ [ ‘-1’ ] HOST

     Open a connection HOST for anonymous FTP. The username used is
     ‘anonymous’.  The password (which will be reported the first time)
     is generated as USER‘@’HOST; this is then stored in the shell
     parameter ‘$EMAIL_ADDR’ which can alternatively be set manually to
     a suitable string.


File: zsh.info,  Node: Directory Management,  Next: Status Commands,  Prev: Opening a Connection,  Up: Functions<4>

24.3.2 Directory Management
---------------------------

‘zfcd’ [ DIR ]

‘zfcd -’

‘zfcd’ OLD NEW

     Change the current directory on the remote server: this is
     implemented to have many of the features of the shell builtin ‘cd’.

     In the first form with DIR present, change to the directory DIR.
     The command ‘zfcd ..’ is treated specially, so is guaranteed to
     work on non-UNIX servers (note this is handled internally by
     ‘zftp’).  If DIR is omitted, has the effect of ‘zfcd ~’.

     The second form changes to the directory previously current.

     The third form attempts to change the current directory by
     replacing the first occurrence of the string OLD with the string
     NEW in the current directory.

     Note that in this command, and indeed anywhere a remote filename is
     expected, the string which on the local host corresponds to ‘~’ is
     converted back to a ‘~’ before being passed to the remote machine.
     This is convenient because of the way expansion is performed on the
     command line before ‘zfcd’ receives a string.  For example, suppose
     the command is ‘zfcd ~/foo’.  The shell will expand this to a full
     path such as ‘zfcd /home/user2/pws/foo’.  At this stage, ‘zfcd’
     recognises the initial path as corresponding to ‘~’ and will send
     the directory to the remote host as ‘~/foo’, so that the ‘~’ will
     be expanded by the server to the correct remote host directory.
     Other named directories of the form ‘~name’ are not treated in this
     fashion.

‘zfhere’

     Change directory on the remote server to the one corresponding to
     the current local directory, with special handling of ‘~’ as in
     ‘zfcd’.  For example, if the current local directory is
     ‘~/foo/bar’, then ‘zfhere’ performs the effect of ‘zfcd ~/foo/bar’.

‘zfdir’ [ ‘-rfd’ ] [ ‘-’ ] [ DIR-OPTIONS ] [ DIR ]

     Produce a long directory listing.  The arguments DIR-OPTIONS and
     DIR are passed directly to the server and their effect is
     implementation dependent, but specifying a particular remote
     directory DIR is usually possible.  The output is passed through a
     pager given by the environment variable ‘$PAGER’, or ‘more’ if that
     is not set.

     The directory is usually cached for re-use.  In fact, two caches
     are maintained.  One is for use when there is no DIR-OPTIONS or
     DIR, i.e.  a full listing of the current remote directory; it is
     flushed when the current remote directory changes.  The other is
     kept for repeated use of ‘zfdir’ with the same arguments; for
     example, repeated use of ‘zfdir /pub/gnu’ will only require the
     directory to be retrieved on the first call.  Alternatively, this
     cache can be re-viewed with the ‘-r’ option.  As relative
     directories will confuse ‘zfdir’, the ‘-f’ option can be used to
     force the cache to be flushed before the directory is listed.  The
     option ‘-d’ will delete both caches without showing a directory
     listing; it will also delete the cache of file names in the current
     remote directory, if any.

‘zfls’ [ LS-OPTIONS ] [ DIR ]

     List files on the remote server.  With no arguments, this will
     produce a simple list of file names for the current remote
     directory.  Any arguments are passed directly to the server.  No
     pager and no caching is used.


File: zsh.info,  Node: Status Commands,  Next: Retrieving Files,  Prev: Directory Management,  Up: Functions<4>

24.3.3 Status Commands
----------------------

‘zftype’ [ TYPE ]

     With no arguments, show the type of data to be transferred, usually
     ASCII or binary.  With an argument, change the type: the types ‘A’
     or ‘ASCII’ for ASCII data and ‘B’ or ‘BINARY’, ‘I’ or ‘IMAGE’ for
     binary data are understood case-insensitively.

‘zfstat’ [ ‘-v’ ]

     Show the status of the current or last connection, as well as the
     status of some of ‘zftp’’s status variables.  With the ‘-v’ option,
     a more verbose listing is produced by querying the server for its
     version of events, too.


File: zsh.info,  Node: Retrieving Files,  Next: Sending Files,  Prev: Status Commands,  Up: Functions<4>

24.3.4 Retrieving Files
-----------------------

The commands for retrieving files all take at least two options.  ‘-G’
suppresses remote filename expansion which would otherwise be performed
(see below for a more detailed description of that).  ‘-t’ attempts to
set the modification time of the local file to that of the remote file:
see the description of the function ‘zfrtime’ below for more
information.

‘zfget’ [ ‘-Gtc’ ] FILE1 …

     Retrieve all the listed files FILE1 … one at a time from the remote
     server.  If a file contains a ‘/’, the full name is passed to the
     remote server, but the file is stored locally under the name given
     by the part after the final ‘/’.  The option ‘-c’ (cat) forces all
     files to be sent as a single stream to standard output; in this
     case the ‘-t’ option has no effect.

‘zfuget’ [ ‘-Gvst’ ] FILE1 …

     As ‘zfget’, but only retrieve files where the version on the remote
     server is newer (has a later modification time), or where the local
     file does not exist.  If the remote file is older but the files
     have different sizes, or if the sizes are the same but the remote
     file is newer, the user will usually be queried.  With the option
     ‘-s’, the command runs silently and will always retrieve the file
     in either of those two cases.  With the option ‘-v’, the command
     prints more information about the files while it is working out
     whether or not to transfer them.

‘zfcget’ [ ‘-Gt’ ] FILE1 …

     As ‘zfget’, but if any of the local files exists, and is shorter
     than the corresponding remote file, the command assumes that it is
     the result of a partially completed transfer and attempts to
     transfer the rest of the file.  This is useful on a poor connection
     which keeps failing.

     Note that this requires a commonly implemented, but non-standard,
     version of the FTP protocol, so is not guaranteed to work on all
     servers.

‘zfgcp’ [ ‘-Gt’ ] REMOTE-FILE LOCAL-FILE

‘zfgcp’ [ ‘-Gt’ ] RFILE1 … LDIR

     This retrieves files from the remote server with arguments behaving
     similarly to the ‘cp’ command.

     In the first form, copy REMOTE-FILE from the server to the local
     file LOCAL-FILE.

     In the second form, copy all the remote files RFILE1 … into the
     local directory LDIR retaining the same basenames.  This assumes
     UNIX directory semantics.


File: zsh.info,  Node: Sending Files,  Next: Closing the Connection,  Prev: Retrieving Files,  Up: Functions<4>

24.3.5 Sending Files
--------------------

‘zfput’ [ ‘-r’ ] FILE1 …

     Send all the FILE1 … given separately to the remote server.  If a
     filename contains a ‘/’, the full filename is used locally to find
     the file, but only the basename is used for the remote file name.

     With the option ‘-r’, if any of the FILES are directories they are
     sent recursively with all their subdirectories, including files
     beginning with ‘.’.  This requires that the remote machine
     understand UNIX file semantics, since ‘/’ is used as a directory
     separator.

‘zfuput’ [ ‘-vs’ ] FILE1 …

     As ‘zfput’, but only send files which are newer than their remote
     equivalents, or if the remote file does not exist.  The logic is
     the same as for ‘zfuget’, but reversed between local and remote
     files.

‘zfcput’ FILE1 …

     As ‘zfput’, but if any remote file already exists and is shorter
     than the local equivalent, assume it is the result of an incomplete
     transfer and send the rest of the file to append to the existing
     part.  As the FTP append command is part of the standard set, this
     is in principle more likely to work than ‘zfcget’.

‘zfpcp’ LOCAL-FILE REMOTE-FILE

‘zfpcp’ LFILE1 … RDIR

     This sends files to the remote server with arguments behaving
     similarly to the ‘cp’ command.

     With two arguments, copy LOCAL-FILE to the server as REMOTE-FILE.

     With more than two arguments, copy all the local files LFILE1 …
     into the existing remote directory RDIR retaining the same
     basenames.  This assumes UNIX directory semantics.

     A problem arises if you attempt to use ‘zfpcp’ LFILE1 RDIR, i.e.
     the second form of copying but with two arguments, as the command
     has no simple way of knowing if RDIR corresponds to a directory or
     a filename.  It attempts to resolve this in various ways.  First,
     if the RDIR argument is ‘.’ or ‘..’ or ends in a slash, it is
     assumed to be a directory.  Secondly, if the operation of copying
     to a remote file in the first form failed, and the remote server
     sends back the expected failure code 553 and a reply including the
     string ‘Is a directory’, then ‘zfpcp’ will retry using the second
     form.


File: zsh.info,  Node: Closing the Connection,  Next: Session Management<2>,  Prev: Sending Files,  Up: Functions<4>

24.3.6 Closing the Connection
-----------------------------

‘zfclose’

     Close the connection.


File: zsh.info,  Node: Session Management<2>,  Next: Bookmarks,  Prev: Closing the Connection,  Up: Functions<4>

24.3.7 Session Management
-------------------------

‘zfsession’ [ ‘-lvod’ ] [ SESSNAME ]

     Allows you to manage multiple FTP sessions at once.  By default,
     connections take place in a session called ‘default’; by giving the
     command ‘zfsession’ SESSNAME you can change to a new or existing
     session with a name of your choice.  The new session remembers its
     own connection, as well as associated shell parameters, and also
     the host/user parameters set by ‘zfparams’.  Hence you can have
     different sessions set up to connect to different hosts, each
     remembering the appropriate host, user and password.

     With no arguments, ‘zfsession’ prints the name of the current
     session; with the option ‘-l’ it lists all sessions which currently
     exist, and with the option ‘-v’ it gives a verbose list showing the
     host and directory for each session, where the current session is
     marked with an asterisk.  With ‘-o’, it will switch to the most
     recent previous session.

     With ‘-d’, the given session (or else the current one) is removed;
     everything to do with it is completely forgotten.  If it was the
     only session, a new session called ‘default’ is created and made
     current.  It is safest not to delete sessions while background
     commands using ‘zftp’ are active.

‘zftransfer’ SESS1‘:’FILE1 SESS2‘:’FILE2

     Transfer files between two sessions; no local copy is made.  The
     file is read from the session SESS1 as FILE1 and written to session
     SESS2 as file FILE2; FILE1 and FILE2 may be relative to the current
     directories of the session.  Either SESS1 or SESS2 may be omitted
     (though the colon should be retained if there is a possibility of a
     colon appearing in the file name) and defaults to the current
     session; FILE2 may be omitted or may end with a slash, in which
     case the basename of FILE1 will be added.  The sessions SESS1 and
     SESS2 must be distinct.

     The operation is performed using pipes, so it is required that the
     connections still be valid in a subshell, which is not the case
     under versions of some operating systems, presumably due to a
     system bug.


File: zsh.info,  Node: Bookmarks,  Next: Other Functions,  Prev: Session Management<2>,  Up: Functions<4>

24.3.8 Bookmarks
----------------

The two functions ‘zfmark’ and ‘zfgoto’ allow you to ‘bookmark’ the
present location (host, user and directory) of the current FTP
connection for later use.  The file to be used for storing and
retrieving bookmarks is given by the parameter ‘$ZFTP_BMFILE’; if not
set when one of the two functions is called, it will be set to the file
‘.zfbkmarks’ in the directory where your zsh startup files live (usually
‘~’).

‘zfmark’ [ BOOKMARK ]

     If given an argument, mark the current host, user and directory
     under the name BOOKMARK for later use by ‘zfgoto’.  If there is no
     connection open, use the values for the last connection immediately
     before it was closed; it is an error if there was none.  Any
     existing bookmark under the same name will be silently replaced.

     If not given an argument, list the existing bookmarks and the
     points to which they refer in the form USER‘@’HOST‘:’DIRECTORY;
     this is the format in which they are stored, and the file may be
     edited directly.

‘zfgoto’ [ ‘-n’ ] BOOKMARK

     Return to the location given by BOOKMARK, as previously set by
     ‘zfmark’.  If the location has user ‘ftp’ or ‘anonymous’, open the
     connection with ‘zfanon’, so that no password is required.  If the
     user and host parameters match those stored for the current
     session, if any, those will be used, and again no password is
     required.  Otherwise a password will be prompted for.

     With the option ‘-n’, the bookmark is taken to be a nickname stored
     by the ‘ncftp’ program in its bookmark file, which is assumed to be
     ‘~/.ncftp/bookmarks’.  The function works identically in other
     ways.  Note that there is no mechanism for adding or modifying
     ‘ncftp’ bookmarks from the zftp functions.


File: zsh.info,  Node: Other Functions,  Prev: Bookmarks,  Up: Functions<4>

24.3.9 Other Functions
----------------------

Mostly, these functions will not be called directly (apart from
‘zfinit’), but are described here for completeness.  You may wish to
alter ‘zftp_chpwd’ and ‘zftp_progress’, in particular.

‘zfinit’ [ ‘-n’ ]

     As described above, this is used to initialize the zftp function
     system.  The ‘-n’ option should be used if the zftp command is
     already built into the shell.

‘zfautocheck’ [ ‘-dn’ ]

     This function is called to implement automatic reopening behaviour,
     as described in more detail below.  The options must appear in the
     first argument; ‘-n’ prevents the command from changing to the old
     directory, while ‘-d’ prevents it from setting the variable
     ‘do_close’, which it otherwise does as a flag for automatically
     closing the connection after a transfer.  The host and directory
     for the last session are stored in the variable ‘$zflastsession’,
     but the internal host/user/password parameters must also be
     correctly set.

‘zfcd_match :var:`prefix` :var:`suffix’‘

     This performs matching for completion of remote directory names.
     If the remote server is UNIX, it will attempt to persuade the
     server to list the remote directory with subdirectories marked,
     which usually works but is not guaranteed.  On other hosts it
     simply calls ‘zfget_match’ and hence completes all files, not just
     directories.  On some systems, directories may not even look like
     filenames.

‘zfget_match :var:`prefix` :var:`suffix’‘

     This performs matching for completion of remote filenames.  It
     caches files for the current directory (only) in the shell
     parameter ‘$zftp_fcache’.  It is in the form to be called by the
     ‘-K’ option of ‘compctl’, but also works when called from a
     widget-style completion function with PREFIX and SUFFIX set
     appropriately.

‘zfrglob :var:`varname’‘

     Perform remote globbing, as describes in more detail below.
     VARNAME is the name of a variable containing the pattern to be
     expanded; if there were any matches, the same variable will be set
     to the expanded set of filenames on return.

‘zfrtime’ LFILE RFILE [ TIME ]

     Set the local file LFILE to have the same modification time as the
     remote file RFILE, or the explicit time TIME in FTP format
     ‘CCYYMMDDhhmmSS’ for the GMT timezone.  This uses the shell’s
     ‘zsh/datetime’ module to perform the conversion from GMT to local
     time.

‘zftp_chpwd’

     This function is called every time a connection is opened, or
     closed, or the remote directory changes.  This version alters the
     title bar of an ‘xterm’-compatible or ‘sun-cmd’ terminal emulator
     to reflect the local and remote hostnames and current directories.
     It works best when combined with the function ‘chpwd’.  In
     particular, a function of the form

           chpwd() {
             if [[ -n $ZFTP_USER ]]; then
               zftp_chpwd
             else
               # usual chpwd e.g put host:directory in title bar
             fi
           }

     fits in well.

‘zftp_progress’

     This function shows the status of the transfer.  It will not write
     anything unless the output is going to a terminal; however, if you
     transfer files in the background, you should turn off progress
     reports by hand using ‘zstyle :zftp:*' progress none’’.  Note also
     that if you alter it, any output ‘must’ be to standard error, as
     standard output may be a file being received.  The form of the
     progress meter, or whether it is used at all, can be configured
     without altering the function, as described in the next section.

‘zffcache’

     This is used to implement caching of files in the current directory
     for each session separately.  It is used by ‘zfget_match’ and
     ‘zfrglob’.


File: zsh.info,  Node: Miscellaneous Features,  Prev: Functions<4>,  Up: Zftp Function System

24.4 Miscellaneous Features
===========================

* Menu:

* Configuration::
* Remote Globbing::
* Automatic and Temporary Reopening::
* Completion: Completion<4>.


File: zsh.info,  Node: Configuration,  Next: Remote Globbing,  Up: Miscellaneous Features

24.4.1 Configuration
--------------------

Various styles are available using the standard shell style mechanism,
described in *note The zsh/zutil Module: ca.  Briefly, the command
‘zstyle :zftp:*'’ STYLE VALUE …’.  defines the STYLE to have value
VALUE; more than one value may be given, although that is not useful in
the cases described here.  These values will then be used throughout the
zftp function system.  For more precise control, the first argument,
which gives a pattern that matches ‘contexts’ in which the style
applies, can be modified to include a particular function, as for
example ‘:zftp:zfget’: the style will then have the given value only in
the ‘zfget’ function, and will override styles set under ‘:zftp:*’.
Note that only the top level function name, as called by the user, is
used; calling of lower level functions is transparent to the user.
Hence modifications to the title bar in ‘zftp_chpwd’ use the contexts
‘:zftp:zfopen’, ‘:zftp:zfcd’, etc., depending where it was called from.
The following styles are understood:

‘progress’

     Controls the way that ‘zftp_progress’ reports on the progress of a
     transfer.  If empty, unset, or ‘none’, no progress report is made;
     if ‘bar’ a growing bar of inverse video is shown; if ‘percent’ (or
     any other string, though this may change in future), the percentage
     of the file transferred is shown.  The bar meter requires that the
     width of the terminal be available via the ‘$COLUMNS’ parameter
     (normally this is set automatically).  If the size of the file
     being transferred is not available, ‘bar’ and ‘percent’ meters will
     simply show the number of bytes transferred so far.

     When ‘zfinit’ is run, if this style is not defined for the context
     ‘:zftp:*’, it will be set to ‘bar’.

‘update’

     Specifies the minimum time interval between updates of the progress
     meter in seconds.  No update is made unless new data has been
     received, so the actual time interval is limited only by
     ‘$ZFTP_TIMEOUT’.

     As described for ‘progress’, ‘zfinit’ will force this to default to
     1.

‘remote-glob’

     If set to ‘1’, ‘yes’ or ‘true’, filename generation (globbing) is
     performed on the remote machine instead of by zsh itself; see
     below.

‘titlebar’

     If set to ‘1’, ‘yes’ or ‘true’, ‘zftp_chpwd’ will put the remote
     host and remote directory into the titlebar of terminal emulators
     such as xterm or sun-cmd that allow this.

     As described for ‘progress’, ‘zfinit’ will force this to default to
     1.

‘chpwd’

     If set to ‘1’ ‘yes’ or ‘true’, ‘zftp_chpwd’ will call the function
     ‘chpwd’ when a connection is closed.  This is useful if the remote
     host details were put into the terminal title bar by ‘zftp_chpwd’
     and your usual ‘chpwd’ also modifies the title bar.

     When ‘zfinit’ is run, it will determine whether ‘chpwd’ exists and
     if so it will set the default value for the style to 1 if none
     exists already.

Note that there is also an associative array ‘zfconfig’ which contains
values used by the function system.  This should not be modified or
overwritten.


File: zsh.info,  Node: Remote Globbing,  Next: Automatic and Temporary Reopening,  Prev: Configuration,  Up: Miscellaneous Features

24.4.2 Remote Globbing
----------------------

The commands for retrieving files usually perform filename generation
(globbing) on their arguments; this can be turned off by passing the
option ‘-G’ to each of the commands.  Normally this operates by
retrieving a complete list of files for the directory in question, then
matching these locally against the pattern supplied.  This has the
advantage that the full range of zsh patterns (respecting the setting of
the option ‘EXTENDED_GLOB’) can be used.  However, it means that the
directory part of a filename will not be expanded and must be given
exactly.  If the remote server does not support the UNIX directory
semantics, directory handling is problematic and it is recommended that
globbing only be used within the current directory.  The list of files
in the current directory, if retrieved, will be cached, so that
subsequent globs in the same directory without an intervening ‘zfcd’ are
much faster.

If the ‘remote-glob’ style (see above) is set, globbing is instead
performed on the remote host: the server is asked for a list of matching
files.  This is highly dependent on how the server is implemented,
though typically UNIX servers will provide support for basic glob
patterns.  This may in some cases be faster, as it avoids retrieving the
entire list of directory contents.


File: zsh.info,  Node: Automatic and Temporary Reopening,  Next: Completion<4>,  Prev: Remote Globbing,  Up: Miscellaneous Features

24.4.3 Automatic and Temporary Reopening
----------------------------------------

As described for the ‘zfopen’ command, a subsequent ‘zfopen’ with no
parameters will reopen the connection to the last host (this includes
connections made with the ‘zfanon’ command).  Opened in this fashion,
the connection starts in the default remote directory and will remain
open until explicitly closed.

Automatic re-opening is also available.  If a connection is not
currently open and a command requiring a connection is given, the last
connection is implicitly reopened.  In this case the directory which was
current when the connection was closed again becomes the current
directory (unless, of course, the command given changes it).  Automatic
reopening will also take place if the connection was close by the remote
server for whatever reason (e.g.  a timeout).  It is not available if
the ‘-1’ option to ‘zfopen’ or ‘zfanon’ was used.

Furthermore, if the command issued is a file transfer, the connection
will be closed after the transfer is finished, hence providing a
one-shot mode for transfers.  This does not apply to directory changing
or listing commands; for example a ‘zfdir’ may reopen a connection but
will leave it open.  Also, automatic closure will only ever happen in
the same command as automatic opening, i.e a ‘zfdir’ directly followed
by a ‘zfget’ will never close the connection automatically.

Information about the previous connection is given by the ‘zfstat’
function.  So, for example, if that reports:

      Session:        default
      Not connected.
      Last session:   ftp.bar.com:/pub/textfiles

then the command ‘zfget file.txt’ will attempt to reopen a connection to
‘ftp.bar.com’, retrieve the file ‘/pub/textfiles/file.txt’, and
immediately close the connection again.  On the other hand, ‘zfcd ..’
will open the connection in the directory ‘/pub’ and leave it open.

Note that all the above is local to each session; if you return to a
previous session, the connection for that session is the one which will
be reopened.


File: zsh.info,  Node: Completion<4>,  Prev: Automatic and Temporary Reopening,  Up: Miscellaneous Features

24.4.4 Completion
-----------------

Completion of local and remote files, directories, sessions and
bookmarks is supported.  The older, ‘compctl’-style completion is
defined when ‘zfinit’ is called; support for the new widget-based
completion system is provided in the function
‘Completion/Zsh/Command/_zftp’, which should be installed with the other
functions of the completion system and hence should automatically be
available.


File: zsh.info,  Node: User Contributions,  Next: Index,  Prev: Zftp Function System,  Up: Top

25 User Contributions
*********************

* Menu:

* Description: Description<10>.
* Utilities::
* Remembering Recent Directories::
* Abbreviated dynamic references to directories::
* Gathering information from version control systems::
* Prompt Themes::
* ZLE Functions::
* Exception Handling::
* MIME Functions::
* Mathematical Functions::
* User Configuration Functions::
* Other Functions: Other Functions<2>.


File: zsh.info,  Node: Description<10>,  Next: Utilities,  Up: User Contributions

25.1 Description
================

The Zsh source distribution includes a number of items contributed by
the user community.  These are not inherently a part of the shell, and
some may not be available in every zsh installation.  The most
significant of these are documented here.  For documentation on other
contributed items such as shell functions, look for comments in the
function source files.


File: zsh.info,  Node: Utilities,  Next: Remembering Recent Directories,  Prev: Description<10>,  Up: User Contributions

25.2 Utilities
==============

* Menu:

* Accessing On-Line Help::
* Recompiling Functions::
* Keyboard Definition::
* Dumping Shell State::
* Manipulating Hook Functions::


File: zsh.info,  Node: Accessing On-Line Help,  Next: Recompiling Functions,  Up: Utilities

25.2.1 Accessing On-Line Help
-----------------------------

The key sequence ‘ESC h’ is normally bound by ZLE to execute the
‘run-help’ widget (see ‘zshzle’).  This invokes the ‘run-help’ command
with the command word from the current input line as its argument.  By
default, ‘run-help’ is an alias for the ‘man’ command, so this often
fails when the command word is a shell builtin or a user-defined
function.  By redefining the ‘run-help’ alias, one can improve the
on-line help provided by the shell.

The ‘helpfiles’ utility, found in the ‘Util’ directory of the
distribution, is a Perl program that can be used to process the zsh
manual to produce a separate help file for each shell builtin and for
many other shell features as well.  The autoloadable ‘run-help’
function, found in ‘Functions/Misc’, searches for these helpfiles and
performs several other tests to produce the most complete help possible
for the command.

Help files are installed by default to a subdirectory of
‘/usr/share/zsh’ or ‘/usr/local/share/zsh’.

To create your own help files with ‘helpfiles’, choose or create a
directory where the individual command help files will reside.  For
example, you might choose ‘~/zsh_help’.  If you unpacked the zsh
distribution in your home directory, you would use the commands:

      mkdir ~/zsh_help
      perl ~/zsh- |release| /Util/helpfiles ~/zsh_help

The ‘HELPDIR’ parameter tells ‘run-help’ where to look for the help
files.  When unset, it uses the default installation path.  To use your
own set of help files, set this to the appropriate path in one of your
startup files:

      HELPDIR=~/zsh_help

To use the ‘run-help’ function, you need to add lines something like the
following to your ‘.zshrc’ or equivalent startup file:

      unalias run-help
      autoload run-help

Note that in order for ‘autoload run-help’ to work, the ‘run-help’ file
must be in one of the directories named in your ‘fpath’ array (see *note
Parameters Used by the Shell: 11.).  This should already be the case if
you have a standard zsh installation; if it is not, copy
‘Functions/Misc/run-help’ to an appropriate directory.


File: zsh.info,  Node: Recompiling Functions,  Next: Keyboard Definition,  Prev: Accessing On-Line Help,  Up: Utilities

25.2.2 Recompiling Functions
----------------------------

If you frequently edit your zsh functions, or periodically update your
zsh installation to track the latest developments, you may find that
function digests compiled with the ‘zcompile’ builtin are frequently out
of date with respect to the function source files.  This is not usually
a problem, because zsh always looks for the newest file when loading a
function, but it may cause slower shell startup and function loading.
Also, if a digest file is explicitly used as an element of ‘fpath’, zsh
won’t check whether any of its source files has changed.

The ‘zrecompile’ autoloadable function, found in ‘Functions/Misc’, can
be used to keep function digests up to date.

‘zrecompile’ [ ‘-qt’ ] [ NAME … ]

‘zrecompile’ [ ‘-qt’ ] ‘-p’ ARG … [ ‘--’ ARG … ]

     This tries to find ‘*.zwc’ files and automatically re-compile them
     if at least one of the original files is newer than the compiled
     file.  This works only if the names stored in the compiled files
     are full paths or are relative to the directory that contains the
     ‘.zwc’ file.

     In the first form, each NAME is the name of a compiled file or a
     directory containing ‘*.zwc’ files that should be checked.  If no
     arguments are given, the directories and ‘*.zwc’ files in ‘fpath’
     are used.

     When ‘-t’ is given, no compilation is performed, but a return
     status of zero (true) is set if there are files that need to be
     re-compiled and non-zero (false) otherwise.  The ‘-q’ option quiets
     the chatty output that describes what ‘zrecompile’ is doing.

     Without the ‘-t’ option, the return status is zero if all files
     that needed re-compilation could be compiled and non-zero if
     compilation for at least one of the files failed.

     If the ‘-p’ option is given, the ARGs are interpreted as one or
     more sets of arguments for ‘zcompile’, separated by ‘--’.  For
     example:

           zrecompile -p \
                      -R ~/.zshrc -- \
                      -M ~/.zcompdump -- \
                      ~/zsh/comp.zwc ~/zsh/Completion/*/_*

     This compiles ‘~/.zshrc’ into ‘~/.zshrc.zwc’ if that doesn’t exist
     or if it is older than ‘~/.zshrc’.  The compiled file will be
     marked for reading instead of mapping.  The same is done for
     ‘~/.zcompdump’ and ‘~/.zcompdump.zwc’, but this compiled file is
     marked for mapping.  The last line re-creates the file
     ‘~/zsh/comp.zwc’ if any of the files matching the given pattern is
     newer than it.

     Without the ‘-p’ option, ‘zrecompile’ does not create function
     digests that do not already exist, nor does it add new functions to
     the digest.

The following shell loop is an example of a method for creating function
digests for all functions in your ‘fpath’, assuming that you have write
permission to the directories:

      for ((i=1; i <= $#fpath; ++i)); do
        dir=$fpath[i]
        zwc=${dir:t}.zwc
        if [[ $dir == (.|..) || $dir == (.|..)/* ]]; then
          continue
        fi
        files=($dir/*(N-.))
        if [[ -w $dir:h && -n $files ]]; then
          files=(${${(M)files%/*/*}#/})
          if ( cd $dir:h &&
               zrecompile -p -U -z $zwc $files ); then
            fpath[i]=$fpath[i].zwc
          fi
        fi
      done

The ‘-U’ and ‘-z’ options are appropriate for functions in the default
zsh installation ‘fpath’; you may need to use different options for your
personal function directories.

Once the digests have been created and your ‘fpath’ modified to refer to
them, you can keep them up to date by running ‘zrecompile’ with no
arguments.


File: zsh.info,  Node: Keyboard Definition,  Next: Dumping Shell State,  Prev: Recompiling Functions,  Up: Utilities

25.2.3 Keyboard Definition
--------------------------

The large number of possible combinations of keyboards, workstations,
terminals, emulators, and window systems makes it impossible for zsh to
have built-in key bindings for every situation.  The ‘zkbd’ utility,
found in ‘Functions/Misc’, can help you quickly create key bindings for
your configuration.

Run ‘zkbd’ either as an autoloaded function, or as a shell script:

      zsh -f ~/zsh- |release| /Functions/Misc/zkbd

When you run ‘zkbd’, it first asks you to enter your terminal type; if
the default it offers is correct, just press return.  It then asks you
to press a number of different keys to determine characteristics of your
keyboard and terminal; ‘zkbd’ warns you if it finds anything out of the
ordinary, such as a Delete key that sends neither ‘^H’ nor ‘^?’.

The keystrokes read by ‘zkbd’ are recorded as a definition for an
associative array named ‘key’, written to a file in the subdirectory
‘.zkbd’ within either your ‘HOME’ or, if specified, ‘ZDOTDIR’ directory.
Alternatively, you can tell ‘zkbd’ the directory to write new files into
with the ‘-d’ option, e.g.  ‘zkbd -d $ZCACHEDIR/zkbd’.  In either case,
the directory is created if it did not exist.  The name of the file is
composed from the ‘TERM’, ‘VENDOR’ and ‘OSTYPE’ parameters, joined by
hyphens.

You may read this file into your ‘.zshrc’ or another startup file with
the ‘source’ or ‘.’ commands, then reference the ‘key’ parameter in
bindkey commands, like this:

      source ${ZDOTDIR:-$HOME}/.zkbd/$TERM-$VENDOR-$OSTYPE
      [[ -n ${key[Left]} ]] && bindkey "${key[Left]}" backward-char
      [[ -n ${key[Right]} ]] && bindkey "${key[Right]}" forward-char
      # etc.

Note that in order for ‘autoload zkbd’ to work, the ‘zkdb’ file must be
in one of the directories named in your ‘fpath’ array (see *note
Parameters Used by the Shell: 11.).  This should already be the case if
you have a standard zsh installation; if it is not, copy
‘Functions/Misc/zkbd’ to an appropriate directory.


File: zsh.info,  Node: Dumping Shell State,  Next: Manipulating Hook Functions,  Prev: Keyboard Definition,  Up: Utilities

25.2.4 Dumping Shell State
--------------------------

Occasionally you may encounter what appears to be a bug in the shell,
particularly if you are using a beta version of zsh or a development
release.  Usually it is sufficient to send a description of the problem
to one of the zsh mailing lists (see *note Mailing Lists: 1a5.), but
sometimes one of the zsh developers will need to recreate your
environment in order to track the problem down.

The script named ‘reporter’, found in the ‘Util’ directory of the
distribution, is provided for this purpose.  (It is also possible to
‘autoload reporter’, but ‘reporter’ is not installed in ‘fpath’ by
default.)  This script outputs a detailed dump of the shell state, in
the form of another script that can be read with ‘zsh -f’ to recreate
that state.

To use ‘reporter’, read the script into your shell with the ‘.’ command
and redirect the output into a file:

      . ~/zsh- |release| /Util/reporter > zsh.report

You should check the ‘zsh.report’ file for any sensitive information
such as passwords and delete them by hand before sending the script to
the developers.  Also, as the output can be voluminous, it’s best to
wait for the developers to ask for this information before sending it.

You can also use ‘reporter’ to dump only a subset of the shell state.
This is sometimes useful for creating startup files for the first time.
Most of the output from reporter is far more detailed than usually is
necessary for a startup file, but the ‘aliases’, ‘options’, and
‘zstyles’ states may be useful because they include only changes from
the defaults.  The ‘bindings’ state may be useful if you have created
any of your own keymaps, because ‘reporter’ arranges to dump the keymap
creation commands as well as the bindings for every keymap.

As is usual with automated tools, if you create a startup file with
‘reporter’, you should edit the results to remove unnecessary commands.
Note that if you’re using the new completion system, you should ‘not’
dump the ‘functions’ state to your startup files with ‘reporter’; use
the ‘compdump’ function instead (see ‘zshcompsys’).

‘reporter’ [ STATE … ]

     Print to standard output the indicated subset of the current shell
     state.  The STATE arguments may be one or more of:

     ‘all’

          Output everything listed below.

     ‘aliases’

          Output alias definitions.

     ‘bindings’

          Output ZLE key maps and bindings.

     ‘completion’

          Output old-style ‘compctl’ commands.  New completion is
          covered by ‘functions’ and ‘zstyles’.

     ‘functions’

          Output autoloads and function definitions.

     ‘limits’

          Output ‘limit’ commands.

     ‘options’

          Output ‘setopt’ commands.

     ‘styles’

          Same as ‘zstyles’.

     ‘variables’

          Output shell parameter assignments, plus ‘export’ commands for
          any environment variables.

     ‘zstyles’

          Output ‘zstyle’ commands.

     If the STATE is omitted, ‘all’ is assumed.

With the exception of ‘all’, every STATE can be abbreviated by any
prefix, even a single letter; thus ‘a’ is the same as ‘aliases’, ‘z’ is
the same as ‘zstyles’, etc.


File: zsh.info,  Node: Manipulating Hook Functions,  Prev: Dumping Shell State,  Up: Utilities

25.2.5 Manipulating Hook Functions
----------------------------------

‘add-zsh-hook’ [ ‘-L’ | ‘-dD’ ] [ ‘-Uzk’ ] HOOK FUNCTION

     Several functions are special to the shell, as described in *note
     Special Functions: 1a8, in that they are automatically called at
     specific points during shell execution.  Each has an associated
     array consisting of names of functions to be called at the same
     point; these are so-called ‘hook functions’.  The shell function
     ‘add-zsh-hook’ provides a simple way of adding or removing
     functions from the array.

     HOOK is one of ‘chpwd’, ‘periodic’, ‘precmd’, ‘preexec’,
     ‘zshaddhistory’, ‘zshexit’, or ‘zsh_directory_name’, the special
     functions in question.  Note that ‘zsh_directory_name’ is called in
     a different way from the other functions, but may still be
     manipulated as a hook.

     FUNCTION is name of an ordinary shell function.  If no options are
     given this will be added to the array of functions to be executed
     in the given context.  Functions are invoked in the order they were
     added.

     If the option ‘-L’ is given, the current values for the hook arrays
     are listed with ‘typeset’.

     If the option ‘-d’ is given, the FUNCTION is removed from the array
     of functions to be executed.

     If the option ‘-D’ is given, the FUNCTION is treated as a pattern
     and any matching names of functions are removed from the array of
     functions to be executed.

     The options ‘-U’, ‘-z’ and ‘-k’ are passed as arguments to
     ‘autoload’ for FUNCTION.  For functions contributed with zsh, the
     options ‘-Uz’ are appropriate.

‘add-zle-hook-widget’ [ ‘-L’ | ‘-dD’ ] [ ‘-Uzk’ ] HOOK WIDGETNAME

     Several widget names are special to the line editor, as described
     in *note Special Widgets: dc, in that they are automatically called
     at specific points during editing.  Unlike function hooks, these do
     not use a predefined array of other names to call at the same
     point; the shell function ‘add-zle-hook-widget’ maintains a similar
     array and arranges for the special widget to invoke those
     additional widgets.

     HOOK is one of ‘isearch-exit’, ‘isearch-update’, ‘line-pre-redraw’,
     ‘line-init’, ‘line-finish’, ‘history-line-set’, or ‘keymap-select’,
     corresponding to each of the special widgets ‘zle-isearch-exit’,
     etc.  The special widget names are also accepted as the HOOK
     argument.

     WIDGETNAME is the name of a ZLE widget.  If no options are given
     this is added to the array of widgets to be invoked in the given
     hook context.  Widgets are invoked in the order they were added,
     with

           zle WIDGETNAME -Nw -f "nolast" -- "$@"

     Note that this means that the ‘WIDGET’ special parameter tracks the
     WIDGETNAME when the widget function is called, rather than tracking
     the name of the corresponding special hook widget.

     If the option ‘-d’ is given, the WIDGETNAME is removed from the
     array of widgets to be executed.

     If the option ‘-D’ is given, the WIDGETNAME is treated as a pattern
     and any matching names of widgets are removed from the array.

     If WIDGETNAME does not name an existing widget when added to the
     array, it is assumed that a shell function also named WIDGETNAME is
     meant to provide the implementation of the widget.  This name is
     therefore marked for autoloading, and the options ‘-U’, ‘-z’ and
     ‘-k’ are passed as arguments to ‘autoload’ as with ‘add-zsh-hook’.
     The widget is also created with ‘zle -N’ WIDGETNAME to cause the
     corresponding function to be loaded the first time the hook is
     called.

     The arrays of WIDGETNAME are currently maintained in ‘zstyle’
     contexts, one for each HOOK context, with a style of ‘widgets’.  If
     the ‘-L’ option is given, this set of styles is listed with ‘zstyle
     -L’.  This implementation may change, and the special widgets that
     refer to the styles are created only if ‘add-zle-hook-widget’ is
     called to add at least one widget, so if this function is used for
     any hooks, then all hooks should be managed only via this function.


File: zsh.info,  Node: Remembering Recent Directories,  Next: Abbreviated dynamic references to directories,  Prev: Utilities,  Up: User Contributions

25.3 Remembering Recent Directories
===================================

The function ‘cdr’ allows you to change the working directory to a
previous working directory from a list maintained automatically.  It is
similar in concept to the directory stack controlled by the ‘pushd’,
‘popd’ and ‘dirs’ builtins, but is more configurable, and as it stores
all entries in files it is maintained across sessions and (by default)
between terminal emulators in the current session.  Duplicates are
automatically removed, so that the list reflects the single most recent
use of each directory.

Note that the ‘pushd’ directory stack is not actually modified or used
by ‘cdr’ unless you configure it to do so as described in the
configuration section below.

* Menu:

* Installation: Installation<2>.
* Use::
* Options: Options<3>.
* Configuration: Configuration<2>.
* Use with Dynamic Directory Naming::
* Details of Directory Handling::


File: zsh.info,  Node: Installation<2>,  Next: Use,  Up: Remembering Recent Directories

25.3.1 Installation
-------------------

The system works by means of a hook function that is called every time
the directory changes.  To install the system, autoload the required
functions and use the ‘add-zsh-hook’ function described above:

      autoload -Uz chpwd_recent_dirs cdr add-zsh-hook
      add-zsh-hook chpwd chpwd_recent_dirs

Now every time you change directly interactively, no matter which
command you use, the directory to which you change will be remembered in
most-recent-first order.


File: zsh.info,  Node: Use,  Next: Options<3>,  Prev: Installation<2>,  Up: Remembering Recent Directories

25.3.2 Use
----------

All direct user interaction is via the ‘cdr’ function.

The argument to cdr is a number N corresponding to the Nth most recently
changed-to directory.  1 is the immediately preceding directory; the
current directory is remembered but is not offered as a destination.
Note that if you have multiple windows open 1 may refer to a directory
changed to in another window; you can avoid this by having per-terminal
files for storing directory as described for the ‘recent-dirs-file’
style below.

If you set the ‘recent-dirs-default’ style described below ‘cdr’ will
behave the same as ‘cd’ if given a non-numeric argument, or more than
one argument.  The recent directory list is updated just the same
however you change directory.

If the argument is omitted, 1 is assumed.  This is similar to ‘pushd’’s
behaviour of swapping the two most recent directories on the stack.

Completion for the argument to ‘cdr’ is available if compinit has been
run; menu selection is recommended, using:

      zstyle ':completion:*:*:cdr:*:*' menu selection

to allow you to cycle through recent directories; the order is
preserved, so the first choice is the most recent directory before the
current one.  The verbose style is also recommended to ensure the
directory is shown; this style is on by default so no action is required
unless you have changed it.


File: zsh.info,  Node: Options<3>,  Next: Configuration<2>,  Prev: Use,  Up: Remembering Recent Directories

25.3.3 Options
--------------

The behaviour of ‘cdr’ may be modified by the following options.

‘-l’

     lists the numbers and the corresponding directories in abbreviated
     form (i.e.  with ‘~’ substitution reapplied), one per line.  The
     directories here are not quoted (this would only be an issue if a
     directory name contained a newline).  This is used by the
     completion system.

‘-r’

     sets the variable ‘reply’ to the current set of directories.
     Nothing is printed and the directory is not changed.

‘-e’

     allows you to edit the list of directories, one per line.  The list
     can be edited to any extent you like; no sanity checking is
     performed.  Completion is available.  No quoting is necessary
     (except for newlines, where I have in any case no sympathy);
     directories are in unabbreviated form and contain an absolute path,
     i.e.  they start with ‘/’.  Usually the first entry should be left
     as the current directory.

‘-p '’PATTERN‘'’

     Prunes any items in the directory list that match the given
     extended glob pattern; the pattern needs to be quoted from
     immediate expansion on the command line.  The pattern is matched
     against each completely expanded file name in the list; the full
     string must match, so wildcards at the end (e.g.  ‘'*removeme*'’)
     are needed to remove entries with a given substring.

     If output is to a terminal, then the function will print the new
     list after pruning and prompt for confirmation by the user.  This
     output and confirmation step can be skipped by using ‘-P’ instead
     of ‘-p’.


File: zsh.info,  Node: Configuration<2>,  Next: Use with Dynamic Directory Naming,  Prev: Options<3>,  Up: Remembering Recent Directories

25.3.4 Configuration
--------------------

Configuration is by means of the styles mechanism that should be
familiar from completion; if not, see the description of the ‘zstyle’
command in *note The zsh/zutil Module: ca.  The context for setting
styles should be ‘':chpwd:*'’ in case the meaning of the context is
extended in future, for example:

      zstyle ':chpwd:*' recent-dirs-max 0

sets the value of the ‘recent-dirs-max’ style to 0.  In practice the
style name is specific enough that a context of ‘*’ should be fine.

An exception is ‘recent-dirs-insert’, which is used exclusively by the
completion system and so has the usual completion system context
(‘':completion:*'’ if nothing more specific is needed), though again
‘'*'’ should be fine in practice.

‘recent-dirs-default’

     If true, and the command is expecting a recent directory index, and
     either there is more than one argument or the argument is not an
     integer, then fall through to “cd”.  This allows the lazy to use
     only one command for directory changing.  Completion recognises
     this, too; see recent-dirs-insert for how to control completion
     when this option is in use.

‘recent-dirs-file’

     The file where the list of directories is saved.  The default is
     ‘${ZDOTDIR:-$HOME}/.chpwd-recent-dirs’, i.e.  this is in your home
     directory unless you have set the variable ‘ZDOTDIR’ to point
     somewhere else.  Directory names are saved in ‘$'’…‘'’ quoted form,
     so each line in the file can be supplied directly to the shell as
     an argument.

     The value of this style may be an array.  In this case, the first
     file in the list will always be used for saving directories while
     any other files are left untouched.  When reading the recent
     directory list, if there are fewer than the maximum number of
     entries in the first file, the contents of later files in the array
     will be appended with duplicates removed from the list shown.  The
     contents of the two files are not sorted together, i.e.  all the
     entries in the first file are shown first.  The special value ‘+’
     can appear in the list to indicate the default file should be read
     at that point.  This allows effects like the following:

           zstyle ':chpwd:*' recent-dirs-file \
           ~/.chpwd-recent-dirs-${TTY##*/} +

     Recent directories are read from a file numbered according to the
     terminal.  If there are insufficient entries the list is
     supplemented from the default file.

     It is possible to use ‘zstyle -e’ to make the directory
     configurable at run time:

           zstyle -e ':chpwd:*' recent-dirs-file pick-recent-dirs-file
           pick-recent-dirs-file() {
             if [[ $PWD = ~/text/writing(|/*) ]]; then
               reply=(~/.chpwd-recent-dirs-writing)
             else
               reply=(+)
             fi
           }

     In this example, if the current directory is ‘~/text/writing’ or a
     directory under it, then use a special file for saving recent
     directories, else use the default.

‘recent-dirs-insert’

     Used by completion.  If ‘recent-dirs-default’ is true, then setting
     this to ‘true’ causes the actual directory, rather than its index,
     to be inserted on the command line; this has the same effect as
     using the corresponding index, but makes the history clearer and
     the line easier to edit.  With this setting, if part of an argument
     was already typed, normal directory completion rather than recent
     directory completion is done; this is because recent directory
     completion is expected to be done by cycling through entries menu
     fashion.

     If the value of the style is ‘always’, then only recent directories
     will be completed; in that case, use the ‘cd’ command when you want
     to complete other directories.

     If the value is ‘fallback’, recent directories will be tried first,
     then normal directory completion is performed if recent directory
     completion failed to find a match.

     Finally, if the value is ‘both’ then both sets of completions are
     presented; the usual tag mechanism can be used to distinguish
     results, with recent directories tagged as ‘recent-dirs’.  Note
     that the recent directories inserted are abbreviated with directory
     names where appropriate.

‘recent-dirs-max’

     The maximum number of directories to save to the file.  If this is
     zero or negative there is no maximum.  The default is 20.  Note
     this includes the current directory, which isn’t offered, so the
     highest number of directories you will be offered is one less than
     the maximum.

‘recent-dirs-prune’

     This style is an array determining what directories should (or
     should not) be added to the recent list.  Elements of the array can
     include:

     ‘parent’

          Prune parents (more accurately, ancestors) from the recent
          list.  If present, changing directly down by any number of
          directories causes the current directory to be overwritten.
          For example, changing from ~pws to ~pws/some/other/dir causes
          ~pws not to be left on the recent directory stack.  This only
          applies to direct changes to descendant directories; earlier
          directories on the list are not pruned.  For example, changing
          from ~pws/yet/another to ~pws/some/other/dir does not cause
          ~pws to be pruned.

     ‘pattern:’PATTERN

          Gives a zsh pattern for directories that should not be added
          to the recent list (if not already there).  This element can
          be repeated to add different patterns.  For example,
          ‘'pattern:/tmp(|/*)'’ stops ‘/tmp’ or its descendants from
          being added.  The ‘EXTENDED_GLOB’ option is always turned on
          for these patterns.

‘recent-dirs-pushd’

     If set to true, ‘cdr’ will use ‘pushd’ instead of ‘cd’ to change
     the directory, so the directory is saved on the directory stack.
     As the directory stack is completely separate from the list of
     files saved by the mechanism used in this file there is no obvious
     reason to do this.


File: zsh.info,  Node: Use with Dynamic Directory Naming,  Next: Details of Directory Handling,  Prev: Configuration<2>,  Up: Remembering Recent Directories

25.3.5 Use with Dynamic Directory Naming
----------------------------------------

It is possible to refer to recent directories using the dynamic
directory name syntax by using the supplied function
‘zsh_directory_name_cdr’ a hook:

      autoload -Uz add-zsh-hook
      add-zsh-hook -Uz zsh_directory_name zsh_directory_name_cdr

When this is done, ‘~[1]’ will refer to the most recent directory other
than $PWD, and so on.  Completion after ‘~[’… also works.


File: zsh.info,  Node: Details of Directory Handling,  Prev: Use with Dynamic Directory Naming,  Up: Remembering Recent Directories

25.3.6 Details of Directory Handling
------------------------------------

This section is for the curious or confused; most users will not need to
know this information.

Recent directories are saved to a file immediately and hence are
preserved across sessions.  Note currently no file locking is applied:
the list is updated immediately on interactive commands and nowhere else
(unlike history), and it is assumed you are only going to change
directory in one window at once.  This is not safe on shared accounts,
but in any case the system has limited utility when someone else is
changing to a different set of directories behind your back.

To make this a little safer, only directory changes instituted from the
command line, either directly or indirectly through shell function calls
(but not through subshells, evals, traps, completion functions and the
like) are saved.  Shell functions should use ‘cd -q’ or ‘pushd -q’ to
avoid side effects if the change to the directory is to be invisible at
the command line.  See the contents of the function ‘chpwd_recent_dirs’
for more details.


File: zsh.info,  Node: Abbreviated dynamic references to directories,  Next: Gathering information from version control systems,  Prev: Remembering Recent Directories,  Up: User Contributions

25.4 Abbreviated dynamic references to directories
==================================================

The dynamic directory naming system is described in *note Dynamic Named
Directories: 78.  In this, a reference to ‘~[’…‘]’ is expanded by a
function found by the hooks mechanism.

The contributed function ‘zsh_directory_name_generic’ provides a system
allowing the user to refer to directories with only a limited amount of
new code.  It supports all three of the standard interfaces for
directory naming: converting from a name to a directory, converting in
the reverse direction to find a short name, and completion of names.

The main feature of this function is a path-like syntax, combining
abbreviations at multiple levels separated by “:”.  As an example,
~[g:p:s] might specify:

‘g’

     The top level directory for your git area.  This first component
     has to match, or the function will return indicating another
     directory name hook function should be tried.

‘p’

     The name of a project within your git area.

‘s’

     The source area within that project.

This allows you to collapse references to long hierarchies to a very
compact form, particularly if the hierarchies are similar across
different areas of the disk.

Name components may be completed: if a description is shown at the top
of the list of completions, it includes the path to which previous
components expand, while the description for an individual completion
shows the path segment it would add.  No additional configuration is
needed for this as the completion system is aware of the dynamic
directory name mechanism.

* Menu:

* Usage::
* Configuration: Configuration<3>.
* Complete Example::


File: zsh.info,  Node: Usage,  Next: Configuration<3>,  Up: Abbreviated dynamic references to directories

25.4.1 Usage
------------

To use the function, first define a wrapper function for your specific
case.  We’ll assume it’s to be autoloaded.  This can have any name but
we’ll refer to it as zdn_mywrapper.  This wrapper function will define
various variables and then call this function with the same arguments
that the wrapper function gets.  This configuration is described below.

Then arrange for the wrapper to be run as a zsh_directory_name hook:

      autoload -Uz add-zsh-hook zsh_directory_name_generic zdn_mywrapper
      add-zsh-hook -U zsh_directory_name zdn_mywrapper


File: zsh.info,  Node: Configuration<3>,  Next: Complete Example,  Prev: Usage,  Up: Abbreviated dynamic references to directories

25.4.2 Configuration
--------------------

The wrapper function should define a local associative array zdn_top.
Alternatively, this can be set with a style called ‘mapping’.  The
context for the style is ‘:zdn:’WRAPPER-NAME where WRAPPER-NAME is the
function calling zsh_directory_name_generic; for example:

      zstyle :zdn:zdn_mywrapper: mapping zdn_mywrapper_top

The keys in this associative array correspond to the first component of
the name.  The values are matching directories.  They may have an
optional suffix with a slash followed by a colon and the name of a
variable in the same format to give the next component.  (The slash
before the colon is to disambiguate the case where a colon is needed in
the path for a drive.  There is otherwise no syntax for escaping this,
so path components whose names start with a colon are not supported.)  A
special component ‘:default:’ specifies a variable in the form ‘/:’VAR
(the path section is ignored and so is usually empty) that will be used
for the next component if no variable is given for the path.  Variables
referred to within ‘zdn_top’ have the same format as ‘zdn_top’ itself,
but contain relative paths.

For example,

      local -A zdn_top=(
        g   ~/git
        ga  ~/alternate/git
        gs  /scratch/$USER/git/:second2
        :default: /:second1
      )

This specifies the behaviour of a directory referred to as ‘~[g:...]’ or
‘~[ga:...]’ or ‘~[gs:...]’.  Later path components are optional; in that
case ‘~[g]’ expands to ‘~/git’, and so on.  ‘gs’ expands to
‘/scratch/$USER/git’ and uses the associative array ‘second2’ to match
the second component; ‘g’ and ‘ga’ use the associative array ‘second1’
to match the second component.

When expanding a name to a directory, if the first component is not ‘g’
or ‘ga’ or ‘gs’, it is not an error; the function simply returns 1 so
that a later hook function can be tried.  However, matching the first
component commits the function, so if a later component does not match,
an error is printed (though this still does not stop later hooks from
being executed).

For components after the first, a relative path is expected, but note
that multiple levels may still appear.  Here is an example of ‘second1’:

      local -A second1=(
        p   myproject
        s   somproject
        os  otherproject/subproject/:third
      )

The path as found from ‘zdn_top’ is extended with the matching
directory, so ‘~[g:p]’ becomes ‘~/git/myproject’.  The slash between is
added automatically (it’s not possible to have a later component modify
the name of a directory already matched).  Only ‘os’ specifies a
variable for a third component, and there’s no ‘:default:’, so it’s an
error to use a name like ‘~[g:p:x]’ or ‘~[ga:s:y]’ because there’s
nowhere to look up the ‘x’ or ‘y’.

The associative arrays need to be visible within this function; the
generic function therefore uses internal variable names beginning
‘_zdn_’ in order to avoid clashes.  Note that the variable ‘reply’ needs
to be passed back to the shell, so should not be local in the calling
function.

The function does not test whether directories assembled by component
actually exist; this allows the system to work across automounted file
systems.  The error from the command trying to use a non-existent
directory should be sufficient to indicate the problem.


File: zsh.info,  Node: Complete Example,  Prev: Configuration<3>,  Up: Abbreviated dynamic references to directories

25.4.3 Complete Example
-----------------------

Here is a full fictitious but usable autoloadable definition of the
example function defined by the code above.  So ‘~[gs:p:s]’ expands to
‘/scratch/$USER/git/myscratchproject/top/srcdir’ (with ‘$USER’ also
expanded).

      local -A zdn_top=(
        g   ~/git
        ga  ~/alternate/git
        gs  /scratch/$USER/git/:second2
        :default: /:second1
      )

      local -A second1=(
        p   myproject
        s   somproject
        os  otherproject/subproject/:third
      )

      local -A second2=(
        p   myscratchproject
        s   somescratchproject
      )

      local -A third=(
        s   top/srcdir
        d   top/documentation
      )

      # autoload not needed if you did this at initialisation...
      autoload -Uz zsh_directory_name_generic
      zsh_directory_name_generic "$@

It is also possible to use global associative arrays, suitably named,
and set the style for the context of your wrapper function to refer to
this.  Then your set up code would contain the following:

      typeset -A zdn_mywrapper_top=(...)
      # ... and so on for other associative arrays ...
      zstyle ':zdn:zdn_mywrapper:' mapping zdn_mywrapper_top
      autoload -Uz add-zsh-hook zsh_directory_name_generic zdn_mywrapper
      add-zsh-hook -U zsh_directory_name zdn_mywrapper

and the function ‘zdn_mywrapper’ would contain only the following:

      zsh_directory_name_generic "$@"


File: zsh.info,  Node: Gathering information from version control systems,  Next: Prompt Themes,  Prev: Abbreviated dynamic references to directories,  Up: User Contributions

25.5 Gathering information from version control systems
=======================================================

In a lot of cases, it is nice to automatically retrieve information from
version control systems (VCSs), such as subversion, CVS or git, to be
able to provide it to the user; possibly in the user’s prompt.  So that
you can instantly tell which branch you are currently on, for example.

In order to do that, you may use the ‘vcs_info’ function.

The following VCSs are supported, showing the abbreviated name by which
they are referred to within the system:

Bazaar (‘bzr’)

     ‘https://bazaar.canonical.com/’

Codeville (‘cdv’)

     ‘http://freecode.com/projects/codeville/’

Concurrent Versioning System (‘cvs’)

     ‘https://www.nongnu.org/cvs/’

Darcs (‘darcs’)

     ‘http://darcs.net/’

Fossil (‘fossil’)

     ‘https://fossil-scm.org/’

Git (‘git’)

     ‘https://git-scm.com/’

GNU arch (‘tla’)

     ‘https://www.gnu.org/software/gnu-arch/’

Mercurial (‘hg’)

     ‘https://www.mercurial-scm.org/’

Monotone (‘mtn’)

     ‘https://monotone.ca/’

Perforce (‘p4’)

     ‘https://www.perforce.com/’

Subversion (‘svn’)

     ‘https://subversion.apache.org/’

SVK (‘svk’)

     ‘https://svk.bestpractical.com/’

There is also support for the patch management system ‘quilt’
(‘https://savannah.nongnu.org/projects/quilt’).  See

vcs_info Quilt Support

below for details.

To load ‘vcs_info’:

      autoload -Uz vcs_info

It can be used in any existing prompt, because it does not require any
specific ‘$psvar’ entries to be available.

* Menu:

* Quickstart::
* Configuration: Configuration<4>.
* Oddities::
* Quilt Support::
* Function Descriptions (Public API): Function Descriptions Public API.
* Variable Description::
* Hooks in vcs_info::
* Examples: Examples<2>.


File: zsh.info,  Node: Quickstart,  Next: Configuration<4>,  Up: Gathering information from version control systems

25.5.1 Quickstart
-----------------

To get this feature working quickly (including colors), you can do the
following (assuming, you loaded ‘vcs_info’ properly - see above):

      zstyle ':vcs_info:*' actionformats \
          '%F{5}(%f%s%F{5})%F{3}-%F{5}[%F{2}%b%F{3}|%F{1}%a%F{5}]%f '
      zstyle ':vcs_info:*' formats       \
          '%F{5}(%f%s%F{5})%F{3}-%F{5}[%F{2}%b%F{5}]%f '
      zstyle ':vcs_info:(sv[nk]|bzr):*' branchformat '%b%F{1}:%F{3}%r'
      precmd () { vcs_info }
      PS1='%F{5}[%F{2}%n%F{5}] %F{3}%3~ ${vcs_info_msg_0_}%f%# '

Obviously, the last two lines are there for demonstration.  You need to
call ‘vcs_info’ from your ‘precmd’ function.  Once that is done you need
a ‘single quoted’ ‘'${vcs_info_msg_0_}'’ in your prompt.

To be able to use ‘'${vcs_info_msg_0_}'’ directly in your prompt like
this, you will need to have the ‘PROMPT_SUBST’ option enabled.

Now call the ‘vcs_info_printsys’ utility from the command line:

      % vcs_info_printsys
      ## list of supported version control backends:
      ## disabled systems are prefixed by a hash sign (#)
      bzr
      cdv
      cvs
      darcs
      fossil
      git
      hg
      mtn
      p4
      svk
      svn
      tla
      ## flavours (cannot be used in the enable or disable styles; they
      ## are enabled and disabled with their master [git-svn -> git])
      ## they *can* be used in contexts: ':vcs_info:git-svn:*'.
      git-p4
      git-svn
      hg-git
      hg-hgsubversion
      hg-hgsvn

You may not want all of these because there is no point in running the
code to detect systems you do not use.  So there is a way to disable
some backends altogether:

      zstyle ':vcs_info:*' disable bzr cdv darcs mtn svk tla

You may also pick a few from that list and enable only those:

      zstyle ':vcs_info:*' enable git cvs svn

If you rerun ‘vcs_info_printsys’ after one of these commands, you will
see the backends listed in the ‘disable’ style (or backends not in the
‘enable’ style - if you used that) marked as disabled by a hash sign.
That means the detection of these systems is skipped ‘completely’.  No
wasted time there.


File: zsh.info,  Node: Configuration<4>,  Next: Oddities,  Prev: Quickstart,  Up: Gathering information from version control systems

25.5.2 Configuration
--------------------

The ‘vcs_info’ feature can be configured via ‘zstyle’.

First, the context in which we are working:

      :vcs_info:VCS-STRING:USER-CONTEXT:REPO-ROOT-NAME

VCS-STRING

     is one of: ‘git’, ‘git-svn’, ‘git-p4’, ‘hg’, ‘hg-git’,
     ‘hg-hgsubversion’, ‘hg-hgsvn’, ‘darcs’, ‘bzr’, ‘cdv’, ‘mtn’, ‘svn’,
     ‘cvs’, ‘svk’, ‘tla’, ‘p4’ or ‘fossil’.  This is followed by
     ‘.quilt-’QUILT-MODE in Quilt mode (see ..  only:: man

          ‘Quilt Support’

          vcs_info Quilt Support

     for details)

     and by ‘+’HOOK-NAME while hooks are active (see ..  only:: man

          ‘Hooks in vcs_info’

          vcs_info Hooks

     for details).

     Currently, hooks in quilt mode don’t add the ‘.quilt-’QUILT-MODE
     information.  This may change in the future.

USER-CONTEXT

     is a freely configurable string, assignable by the user as the
     first argument to ‘vcs_info’ (see its description below).

REPO-ROOT-NAME

     is the name of a repository in which you want a style to match.
     So, if you want a setting specific to ‘/usr/src/zsh’, with that
     being a CVS checkout, you can set REPO-ROOT-NAME to ‘zsh’ to make
     it so.

There are three special values for VCS-STRING: The first is named
‘-init-’, that is in effect as long as there was no decision what VCS
backend to use.  The second is ‘-preinit-’; it is used ‘before’
‘vcs_info’ is run, when initializing the data exporting variables.  The
third special value is ‘formats’ and is used by the ‘vcs_info_lastmsg’
for looking up its styles.

The initial value of REPO-ROOT-NAME is ‘-all-’ and it is replaced with
the actual name, as soon as it is known.  Only use this part of the
context for defining the ‘formats’, ‘actionformats’ or ‘branchformat’
styles, as it is guaranteed that REPO-ROOT-NAME is set up correctly for
these only.  For all other styles, just use ‘'*'’ instead.

There are two pre-defined values for USER-CONTEXT:

‘default’

     the one used if none is specified

‘command’

     used by vcs_info_lastmsg to lookup its styles

You can of course use ‘':vcs_info:*'’ to match all VCSs in all
user-contexts at once.

This is a description of all styles that are looked up.

‘formats’

     A list of formats, used when actionformats is not used (which is
     most of the time).

‘actionformats’

     A list of formats, used if there is a special action going on in
     your current repository; like an interactive rebase or a merge
     conflict.

‘branchformat’

     Some backends replace ‘%b’ in the formats and actionformats styles
     above, not only by a branch name but also by a revision number.
     This style lets you modify how that string should look.

‘nvcsformats’

     These “formats” are set when we didn’t detect a version control
     system for the current directory or ‘vcs_info’ was disabled.  This
     is useful if you want ‘vcs_info’ to completely take over the
     generation of your prompt.  You would do something like
     ‘PS1='${vcs_info_msg_0_}'’ to accomplish that.

‘hgrevformat’

     ‘hg’ uses both a hash and a revision number to reference a specific
     changeset in a repository.  With this style you can format the
     revision string (see ‘branchformat’) to include either or both.
     It’s only useful when ‘get-revision’ is true.  Note, the full
     40-character revision id is not available (except when using the
     ‘use-simple’ option) because executing hg more than once per prompt
     is too slow; you may customize this behavior using hooks.

‘max-exports’

     Defines the maximum number of ‘vcs_info_msg_*_’ variables
     ‘vcs_info’ will set.

‘enable’

     A list of backends you want to use.  Checked in the ‘-init-’
     context.  If this list contains an item called ‘NONE’ no backend is
     used at all and ‘vcs_info’ will do nothing.  If this list contains
     ‘ALL’, ‘vcs_info’ will use all known backends.  Only with ‘ALL’ in
     ‘enable’ will the ‘disable’ style have any effect.  ‘ALL’ and
     ‘NONE’ are case insensitive.

‘disable’

     A list of VCSs you don’t want ‘vcs_info’ to test for repositories
     (checked in the ‘-init-’ context, too).  Only used if ‘enable’
     contains ‘ALL’.

‘disable-patterns’

     A list of patterns that are checked against ‘$PWD’.  If a pattern
     matches, ‘vcs_info’ will be disabled.  This style is checked in the
     ‘:vcs_info:-init-:*:-all-’ context.

     Say, ‘~/.zsh’ is a directory under version control, in which you do
     not want ‘vcs_info’ to be active, do:

           zstyle ':vcs_info:*' disable-patterns "${(b)HOME}/.zsh(|/*)"

‘use-quilt’

     If enabled, the ‘quilt’ support code is active in ‘addon’ mode.
     See ..  only:: man

          ‘Quilt Support’

          vcs_info Quilt Support

     for details.

‘quilt-standalone’

     If enabled, ‘standalone’ mode detection is attempted if no VCS is
     active in a given directory.  See ..  only:: man

          ‘Quilt Support’

          vcs_info Quilt Support

     for details.

‘quilt-patch-dir’

     Overwrite the value of the ‘$QUILT_PATCHES’ environment variable.
     See

          vcs_info Quilt Support

     for details.

‘quiltcommand’

     When ‘quilt’ itself is called in quilt support, the value of this
     style is used as the command name.

‘check-for-changes’

     If enabled, this style causes the ‘%c’ and ‘%u’ format escapes to
     show when the working directory has uncommitted changes.  The
     strings displayed by these escapes can be controlled via the
     ‘stagedstr’ and ‘unstagedstr’ styles.  The only backends that
     currently support this option are ‘git’, ‘hg’, and ‘bzr’ (the
     latter two only support unstaged).

     For this style to be evaluated with the ‘hg’ backend, the
     ‘get-revision’ style needs to be set and the ‘use-simple’ style
     needs to be unset.  The latter is the default; the former is not.

     With the ‘bzr’ backend, ‘lightweight checkouts’ only honor this
     style if the ‘use-server’ style is set.

     Note, the actions taken if this style is enabled are potentially
     expensive (read: they may be slow, depending on how big the current
     repository is).  Therefore, it is disabled by default.

‘check-for-staged-changes’

     This style is like ‘check-for-changes’, but it never checks the
     worktree files, only the metadata in the ‘.${vcs}’ dir.  Therefore,
     this style initializes only the ‘%c’ escape (with ‘stagedstr’) but
     not the ‘%u’ escape.  This style is faster than
     ‘check-for-changes’.

     In the ‘git’ backend, this style checks for changes in the index.
     Other backends do not currently implement this style.

     This style is disabled by default.

‘stagedstr’

     This string will be used in the ‘%c’ escape if there are staged
     changes in the repository.

‘unstagedstr’

     This string will be used in the ‘%u’ escape if there are unstaged
     changes in the repository.

‘command’

     This style causes ‘vcs_info’ to use the supplied string as the
     command to use as the VCS’s binary.  Note, that setting this in
     ‘‘:vcs_info:*’’ is not a good idea.

     If the value of this style is empty (which is the default), the
     used binary name is the name of the backend in use (e.g.  ‘svn’ is
     used in an ‘svn’ repository).

     The ‘repo-root-name’ part in the context is always the default
     ‘-all-’ when this style is looked up.

     For example, this style can be used to use binaries from
     non-default installation directories.  Assume, ‘git’ is installed
     in /usr/bin but your sysadmin installed a newer version in
     /usr/local/bin.  Instead of changing the order of your ‘$PATH’
     parameter, you can do this:

           zstyle ':vcs_info:git:*:-all-' command /usr/local/bin/git

‘use-server’

     This is used by the Perforce backend (‘p4’) to decide if it should
     contact the Perforce server to find out if a directory is managed
     by Perforce.  This is the only reliable way of doing this, but runs
     the risk of a delay if the server name cannot be found.  If the
     server (more specifically, the HOST‘:’PORT pair describing the
     server) cannot be contacted, its name is put into the associative
     array ‘vcs_info_p4_dead_servers’ and is not contacted again during
     the session until it is removed by hand.  If you do not set this
     style, the ‘p4’ backend is only usable if you have set the
     environment variable ‘P4CONFIG’ to a file name and have
     corresponding files in the root directories of each Perforce
     client.  See comments in the function ‘VCS_INFO_detect_p4’ for more
     detail.

     The Bazaar backend (‘bzr’) uses this to permit contacting the
     server about lightweight checkouts, see the ‘check-for-changes’
     style.

‘use-simple’

     If there are two different ways of gathering information, you can
     select the simpler one by setting this style to true; the default
     is to use the not-that-simple code, which is potentially a lot
     slower but might be more accurate in all possible cases.  This
     style is used by the ‘bzr’, ‘hg’, and ‘git’ backends.  In the case
     of ‘hg’ it will invoke the external hexdump program to parse the
     binary dirstate cache file; this method will not return the local
     revision number.

‘get-revision’

     If set to true, vcs_info goes the extra mile to figure out the
     revision of a repository’s work tree (currently for the ‘git’ and
     ‘hg’ backends, where this kind of information is not always vital).
     For ‘git’, the hash value of the currently checked out commit is
     available via the ‘%i’ expansion.  With ‘hg’, the local revision
     number and the corresponding global hash are available via ‘%i’.

‘get-mq’

     If set to true, the ‘hg’ backend will look for a Mercurial Queue
     (‘mq’) patch directory.  Information will be available via the ‘%m’
     replacement.

‘get-bookmarks’

     If set to true, the ‘hg’ backend will try to get a list of current
     bookmarks.  They will be available via the ‘%m’ replacement.

     The default is to generate a comma-separated list of all bookmark
     names that refer to the currently checked out revision.  If a
     bookmark is active, its name is suffixed an asterisk and placed
     first in the list.

‘use-prompt-escapes’

     Determines if we assume that the assembled string from ‘vcs_info’
     includes prompt escapes.  (Used by ‘vcs_info_lastmsg’.)

‘debug’

     Enable debugging output to track possible problems.  Currently this
     style is only used by ‘vcs_info’’s hooks system.

‘hooks’

     A list style that defines hook-function names.  See ..  only:: man

          ‘Hooks in vcs_info’

     vcs_info Hooks

     below for details.

‘patch-format’

‘nopatch-format’

     This pair of styles format the patch information used by the ‘%m’
     expando in formats and actionformats for the ‘git’ and ‘hg’
     backends.  The value is subject to certain ‘%’-expansions described
     below.  The expanded value is made available in the global
     ‘backend_misc’ array as ‘${backend_misc[patches]}’ (also if a
     ‘set-patch-format’ hook is used).

‘get-unapplied’

     This boolean style controls whether a backend should attempt to
     gather a list of unapplied patches (for example with Mercurial
     Queue patches).

     Used by the ‘quilt’, ‘hg’, and ‘git’ backends.

The default values for these styles in all contexts are:

‘formats’

     “ (%s)-[%b]%u%c-”

‘actionformats’

     “ (%s)-[%b|%a]%u%c-”

‘branchformat’

     “%b:%r” (for bzr, svn, svk and hg)

‘nvcsformats’

     “”

‘hgrevformat’

     “%r:%h”

‘max-exports’

     2

‘enable’

     ALL

‘disable’

     (empty list)

‘disable-patterns’

     (empty list)

‘check-for-changes’

     false

‘check-for-staged-changes’

     false

‘stagedstr’

     (string: “S”)

‘unstagedstr’

     (string: “U”)

‘command’

     (empty string)

‘use-server’

     false

‘use-simple’

     false

‘get-revision’

     false

‘get-mq’

     true

‘get-bookmarks’

     false

‘use-prompt-escapes’

     true

‘debug’

     false

‘hooks’

     (empty list)

‘use-quilt’

     false

‘quilt-standalone’

     false

‘quilt-patch-dir’

     empty - use ‘$QUILT_PATCHES’

‘quiltcommand’

     quilt

‘patch-format’

     BACKEND DEPENDENT

‘nopatch-format’

     BACKEND DEPENDENT

‘get-unapplied’

     false

In normal ‘formats’ and ‘actionformats’ the following replacements are
done:

‘%s’

     The VCS in use (git, hg, svn, etc.).

‘%b’

     Information about the current branch.

‘%a’

     An identifier that describes the action.  Only makes sense in
     ‘actionformats’.

‘%i’

     The current revision number or identifier.  For ‘hg’ the
     ‘hgrevformat’ style may be used to customize the output.

‘%c’

     The string from the ‘stagedstr’ style if there are staged changes
     in the repository.

‘%u’

     The string from the ‘unstagedstr’ style if there are unstaged
     changes in the repository.

‘%R’

     The base directory of the repository.

‘%r’

     The repository name.  If ‘%R’ is ‘/foo/bar/repoXY’, ‘%r’ is
     ‘repoXY’.

‘%S’

     A subdirectory within a repository.  If ‘$PWD’ is
     ‘/foo/bar/repoXY/beer/tasty’, ‘%S’ is ‘beer/tasty’.

‘%m’

     A “misc” replacement.  It is at the discretion of the backend to
     decide what this replacement expands to.

     The ‘hg’ and ‘git’ backends use this expando to display patch
     information.  ‘hg’ sources patch information from the ‘mq’
     extensions; ‘git’ from in-progress ‘rebase’ and ‘cherry-pick’
     operations and from the ‘stgit’ extension.  The ‘patch-format’ and
     ‘nopatch-format’ styles control the generated string.  The former
     is used when at least one patch from the patch queue has been
     applied, and the latter otherwise.

     The ‘hg’ backend displays bookmark information in this expando (in
     addition to ‘mq’ information).  See the ‘get-mq’ and
     ‘get-bookmarks’ styles.  Both of these styles may be enabled at the
     same time.  If both are enabled, both resulting strings will be
     shown separated by a semicolon (that cannot currently be
     customized).

     The ‘quilt’ ‘standalone’ backend sets this expando to the same
     value as the ‘%Q’ expando.

‘%Q’

     Quilt series information.  When quilt is used (either in ‘addon’
     mode or as a ‘standalone’ backend), this expando is set to the
     quilt series’ ‘patch-format’ string.  The ‘set-patch-format’ hook
     and ‘nopatch-format’ style are honoured.

     See ..  only:: man

          ‘Quilt Support’

          vcs_info Quilt Support

     below for details.

In ‘branchformat’ these replacements are done:

‘%b’

     The branch name.  For ‘hg’, the branch name can include a topic
     name.

‘%r’

     The current revision number or the ‘hgrevformat’ style for ‘hg’.

In ‘hgrevformat’ these replacements are done:

‘%r’

     The current local revision number.

‘%h’

     The current global revision identifier.

In ‘patch-format’ and ‘nopatch-format’ these replacements are done:

‘%p’

     The name of the top-most applied patch; may be overridden by the
     ‘applied-string’ hook.

‘%u’

     The number of unapplied patches; may be overridden by the
     ‘unapplied-string’ hook.

‘%n’

     The number of applied patches.

‘%c’

     The number of unapplied patches.

‘%a’

     The number of all patches (‘%a = %n + %c’).

‘%g’

     The names of active ‘mq’ guards (‘hg’ backend).

‘%G’

     The number of active ‘mq’ guards (‘hg’ backend).

Not all VCS backends have to support all replacements.  For
‘nvcsformats’ no replacements are performed at all, it is just a string.


File: zsh.info,  Node: Oddities,  Next: Quilt Support,  Prev: Configuration<4>,  Up: Gathering information from version control systems

25.5.3 Oddities
---------------

If you want to use the ‘%b’ (bold off) prompt expansion in ‘formats’,
which expands ‘%b’ itself, use ‘%%b’.  That will cause the ‘vcs_info’
expansion to replace ‘%%b’ with ‘%b’, so that zsh’s prompt expansion
mechanism can handle it.  Similarly, to hand down ‘%b’ from
‘branchformat’, use ‘%%%%b’.  Sorry for this inconvenience, but it
cannot be easily avoided.  Luckily we do not clash with a lot of prompt
expansions and this only needs to be done for those.

When one of the ‘gen-applied-string’, ‘gen-unapplied-string’, and
‘set-patch-format’ hooks is defined, applying ‘%’-escaping
(‘foo=${foo//%'/%%}’’) to the interpolated values for use in the prompt
is the responsibility of those hooks (jointly); when neither of those
hooks is defined, ‘vcs_info’ handles escaping by itself.  We regret this
coupling, but it was required for backwards compatibility.


File: zsh.info,  Node: Quilt Support,  Next: Function Descriptions Public API,  Prev: Oddities,  Up: Gathering information from version control systems

25.5.4 Quilt Support
--------------------

‘Quilt’ is not a version control system, therefore this is not
implemented as a backend.  It can help keeping track of a series of
patches.  People use it to keep a set of changes they want to use on top
of software packages (which is tightly integrated into the package build
process - the Debian project does this for a large number of packages).
Quilt can also help individual developers keep track of their own
patches on top of real version control systems.

The ‘vcs_info’ integration tries to support both ways of using quilt by
having two slightly different modes of operation: ‘addon’ mode and
‘standalone’ mode).

Quilt integration is off by default; to enable it, set the ‘use-quilt’
style, and add ‘%Q’ to your ‘formats’ or ‘actionformats’ style:

      zstyle ':vcs_info:*' use-quilt true

Styles looked up from the Quilt support code include ‘.quilt-’QUILT-MODE
in the VCS-STRING part of the context, where QUILT-MODE is either
‘addon’ or ‘standalone’.  Example:
‘:vcs_info:git.quilt-addon:default:’REPO-ROOT-NAME.

For ‘addon’ mode to become active ‘vcs_info’ must have already detected
a real version control system controlling the directory.  If that is the
case, a directory that holds quilt’s patches needs to be found.  That
directory is configurable via the ‘QUILT_PATCHES’ environment variable.
If that variable exists its value is used, otherwise the value ‘patches’
is assumed.  The value from ‘$QUILT_PATCHES’ can be overwritten using
the ‘quilt-patch-dir’ style.  (Note: you can use ‘vcs_info’ to keep the
value of ‘$QUILT_PATCHES’ correct all the time via the ‘post-quilt’
hook).

When the directory in question is found, quilt is assumed to be active.
To gather more information, ‘vcs_info’ looks for a directory called
‘.pc’; Quilt uses that directory to track its current state.  If this
directory does not exist we know that quilt has not done anything to the
working directory (read: no patches have been applied yet).

If patches are applied, ‘vcs_info’ will try to find out which.  If you
want to know which patches of a series are not yet applied, you need to
activate the ‘get-unapplied’ style in the appropriate context.

‘vcs_info’ allows for very detailed control over how the gathered
information is presented (see

vcs_info Configuration and vcs_info Hooks

), all of which are documented below.  Note there are a number of other
patch tracking systems that work on top of a certain version control
system (like ‘stgit’ for ‘git’, or ‘mq’ for ‘hg’); the configuration for
systems like that are generally configured the same way as the ‘quilt’
support.

If the ‘quilt’ support is working in ‘addon’ mode, the produced string
is available as a simple format replacement (‘%Q’ to be precise), which
can be used in ‘formats’ and ‘actionformats’; see below for details).

If, on the other hand, the support code is working in ‘standalone’ mode,
‘vcs_info’ will pretend as if ‘quilt’ were an actual version control
system.  That means that the version control system identifier (which
otherwise would be something like ‘svn’ or ‘cvs’) will be set to
‘-quilt-’.  This has implications on the used style context where this
identifier is the second element.  ‘vcs_info’ will have filled in a
proper value for the “repository’s” root directory and the string
containing the information about quilt’s state will be available as the
‘misc’ replacement (and ‘%Q’ for compatibility with ‘addon’ mode).

What is left to discuss is how ‘standalone’ mode is detected.  The
detection itself is a series of searches for directories.  You can have
this detection enabled all the time in every directory that is not
otherwise under version control.  If you know there is only a limited
set of trees where you would like ‘vcs_info’ to try and look for Quilt
in ‘standalone’ mode to minimise the amount of searching on every call
to ‘vcs_info’, there are a number of ways to do that:

Essentially, ‘standalone’ mode detection is controlled by a style called
‘quilt-standalone’.  It is a string style and its value can have
different effects.  The simplest values are: ‘always’ to run detection
every time ‘vcs_info’ is run, and ‘never’ to turn the detection off
entirely.

If the value of ‘quilt-standalone’ is something else, it is interpreted
differently.  If the value is the name of a scalar variable the value of
that variable is checked and that value is used in the same
‘always’/‘never’ way as described above.

If the value of ‘quilt-standalone’ is an array, the elements of that
array are used as directory names under which you want the detection to
be active.

If ‘quilt-standalone’ is an associative array, the keys are taken as
directory names under which you want the detection to be active, but
only if the corresponding value is the string ‘true’.

Last, but not least, if the value of ‘quilt-standalone’ is the name of a
function, the function is called without arguments and the return value
decides whether detection should be active.  A ‘0’ return value is true;
a non-zero return value is interpreted as false.

Note, if there is both a function and a variable by the name of
‘quilt-standalone’, the function will take precedence.


File: zsh.info,  Node: Function Descriptions Public API,  Next: Variable Description,  Prev: Quilt Support,  Up: Gathering information from version control systems

25.5.5 Function Descriptions (Public API)
-----------------------------------------

‘vcs_info’ [USER-CONTEXT]

     The main function, that runs all backends and assembles all data
     into ‘${vcs_info_msg_*_}’.  This is the function you want to call
     from ‘precmd’ if you want to include up-to-date information in your
     prompt (see

     vcs_info Variables

     below).  If an argument is given, that string will be used instead
     of ‘default’ in the USER-CONTEXT field of the style context.

‘vcs_info_hookadd’

     Statically registers a number of functions to a given hook.  The
     hook needs to be given as the first argument; what follows is a
     list of hook-function names to register to the hook.  The ‘+vi-’
     prefix needs to be left out here.  See ..  only:: man

          ‘Hooks in vcs_info’

     vcs_info Hooks

     below for details.

‘vcs_info_hookdel’

     Remove hook-functions from a given hook.  The hook needs to be
     given as the first non-option argument; what follows is a list of
     hook-function names to un-register from the hook.  If ‘-a’ is used
     as the first argument, ‘all’ occurrences of the functions are
     unregistered.  Otherwise only the last occurrence is removed (if a
     function was registered to a hook more than once).  The ‘+vi-’
     prefix needs to be left out here.  See ..  only:: man

          ‘Hooks in vcs_info’

     vcs_info Hooks

     below for details.

‘vcs_info_lastmsg’

     Outputs the current values of ‘${vcs_info_msg_*_}’.  Takes into
     account the value of the ‘use-prompt-escapes’ style in
     ‘':vcs_info:formats:command:-all-'’.  It also only prints
     ‘max-exports’ values.

‘vcs_info_printsys’ [USER-CONTEXT]

     Prints a list of all supported version control systems.  Useful to
     find out possible contexts (and which of them are enabled) or
     values for the ‘disable’ style.

‘vcs_info_setsys’

     Initializes ‘vcs_info’’s internal list of available backends.  With
     this function, you can add support for new VCSs without restarting
     the shell.

All functions named ‘VCS_INFO_*’ are for internal use only.


File: zsh.info,  Node: Variable Description,  Next: Hooks in vcs_info,  Prev: Function Descriptions Public API,  Up: Gathering information from version control systems

25.5.6 Variable Description
---------------------------

‘${vcs_info_msg_’N‘_}’ (Note the trailing underscore)

     Where N is an integer, e.g., ‘vcs_info_msg_0_’.  These variables
     are the storage for the informational message the last ‘vcs_info’
     call has assembled.  These are strongly connected to the ‘formats’,
     ‘actionformats’ and ‘nvcsformats’ styles described above.  Those
     styles are lists.  The first member of that list gets expanded into
     ‘${vcs_info_msg_0_}’, the second into ‘${vcs_info_msg_1_}’ and the
     Nth into ‘${vcs_info_msg_N-1_}’.  (See the ‘max-exports’ style
     above.)

All variables named ‘VCS_INFO_*’ are for internal use only.


File: zsh.info,  Node: Hooks in vcs_info,  Next: Examples<2>,  Prev: Variable Description,  Up: Gathering information from version control systems

25.5.7 Hooks in vcs_info
------------------------

Hooks are places in ‘vcs_info’ where you can run your own code.  That
code can communicate with the code that called it and through that,
change the system’s behaviour.

For configuration, hooks change the style context:

      :vcs_info:VCS-STRING+:var:‘hook-name’:USER-CONTEXT:REPO-ROOT-NAME

To register functions to a hook, you need to list them in the ‘hooks’
style in the appropriate context.

Example:

      zstyle ':vcs_info:*+foo:*' hooks bar baz

This registers functions to the hook ‘foo’ for all backends.  In order
to avoid namespace problems, all registered function names are prepended
by a ‘+vi-’, so the actual functions called for the ‘foo’ hook are
‘+vi-bar’ and ‘+vi-baz’.

If you would like to register a function to a hook regardless of the
current context, you may use the ‘vcs_info_hookadd’ function.  To remove
a function that was added like that, the ‘vcs_info_hookdel’ function can
be used.

If something seems weird, you can enable the ‘debug’ boolean style in
the proper context and the hook-calling code will print what it tried to
execute and whether the function in question existed.

When you register more than one function to a hook, all functions are
executed one after another until one function returns non-zero or until
all functions have been called.  Context-sensitive hook functions are
executed ‘before’ statically registered ones (the ones added by
‘vcs_info_hookadd’).

You may pass data between functions via an associative array,
‘user_data’.  For example:

      +vi-git-myfirsthook(){
          user_data[myval]=$myval
      }
      +vi-git-mysecondhook(){
          # do something with ${user_data[myval]}
      }

There are a number of variables that are special in hook contexts:

‘ret’

     The return value that the hooks system will return to the caller.
     The default is an integer ‘zero’.  If and how a changed ‘ret’ value
     changes the execution of the caller depends on the specific hook.
     See the hook documentation below for details.

‘hook_com’

     An associated array which is used for bidirectional communication
     from the caller to hook functions.  The used keys depend on the
     specific hook.

‘context’

     The active context of the hook.  Functions that wish to change this
     variable should make it local scope first.

‘vcs’

     The current VCS after it was detected.  The same values as in the
     enable/disable style are used.  Available in all hooks except
     ‘start-up’.

Finally, the full list of currently available hooks:

‘start-up’

     Called after starting ‘vcs_info’ but before the VCS in this
     directory is determined.  It can be used to deactivate ‘vcs_info’
     temporarily if necessary.  When ‘ret’ is set to ‘1’, ‘vcs_info’
     aborts and does nothing; when set to ‘2’, ‘vcs_info’ sets up
     everything as if no version control were active and exits.

‘pre-get-data’

     Same as ‘start-up’ but after the VCS was detected.

‘gen-hg-bookmark-string’

     Called in the Mercurial backend when a bookmark string is
     generated; the ‘get-revision’ and ‘get-bookmarks’ styles must be
     true.

     This hook gets the names of the Mercurial bookmarks that ‘vcs_info’
     collected from ‘hg’.

     If a bookmark is active, the key ‘${hook_com[hg-active-bookmark]}’
     is set to its name.  The key is otherwise unset.

     When setting ‘ret’ to non-zero, the string in
     ‘${hook_com[hg-bookmark-string]}’ will be used in the ‘%m’ escape
     in ‘formats’ and ‘actionformats’ and will be available in the
     global ‘backend_misc’ array as ‘${backend_misc[bookmarks]}’.

‘gen-applied-string’

     Called in the ‘git’ (with ‘stgit’ or during rebase or merge), and
     ‘hg’ (with ‘mq’) backends and in ‘quilt’ support when the
     ‘applied-string’ is generated; the ‘use-quilt’ zstyle must be true
     for ‘quilt’ (the ‘mq’ and ‘stgit’ backends are active by default).

     The arguments to this hook describe applied patches in the opposite
     order, which means that the first argument is the top-most patch
     and so forth.

     When the patches’ log messages can be extracted, those are embedded
     within each argument after a space, so each argument is of the form
     PATCH-NAME FIRST LINE OF THE LOG MESSAGE, where PATCH-NAME contains
     no whitespace.  The ‘mq’ backend passes arguments of the form PATCH
     NAME, with possible embedded spaces, but without extracting the
     patch’s log message.

     When setting ‘ret’ to non-zero, the string in
     ‘${hook_com[applied-string]}’ will be available as ‘%p’ in the
     ‘patch-format’ and ‘nopatch-format’ styles.  This hook is, in
     concert with ‘set-patch-format’, responsible for ‘%’-escaping that
     value for use in the prompt.  (See ..  only:: man

          the ‘Oddities’ subsection above

     vcs_info Oddities

     .)

     The ‘quilt’ backend passes to this hook the inputs
     ‘${hook_com[quilt-patches-dir]}’ and, if it has been determined,
     ‘${hook_com[quilt-pc-dir]}’.

‘gen-unapplied-string’

     Called in the ‘git’ (with ‘stgit’ or during rebase), and ‘hg’ (with
     ‘mq’) backend and in ‘quilt’ support when the ‘unapplied-string’ is
     generated; the ‘get-unapplied’ style must be true.

     This hook gets the names of all unapplied patches which ‘vcs_info’
     in order, which means that the first argument is the patch
     next-in-line to be applied and so forth.

     The format of each argument is as for ‘gen-applied-string’, above.

     When setting ‘ret’ to non-zero, the string in
     ‘${hook_com[unapplied-string]}’ will be available as ‘%u’ in the
     ‘patch-format’ and ‘nopatch-format’ styles.  This hook is, in
     concert with ‘set-patch-format’, responsible for ‘%’-escaping that
     value for use in the prompt.  (See ..  only:: man

          the ‘Oddities’ subsection above

     vcs_info Oddities

     .)

     The ‘quilt’ backend passes to this hook the inputs
     ‘${hook_com[quilt-patches-dir]}’ and, if it has been determined,
     ‘${hook_com[quilt-pc-dir]}’.

‘gen-mqguards-string’

     Called in the ‘hg’ backend when ‘guards-string’ is generated; the
     ‘get-mq’ style must be true (default).

     This hook gets the names of any active ‘mq’ guards.

     When setting ‘ret’ to non-zero, the string in
     ‘${hook_com[guards-string]}’ will be used in the ‘%g’ escape in the
     ‘patch-format’ and ‘nopatch-format’ styles.

‘no-vcs’

     This hooks is called when no version control system was detected.

     The ‘hook_com’ parameter is not used.

‘post-backend’

     Called as soon as the backend has finished collecting information.

     The ‘hook_com’ keys available are as for the ‘set-message’ hook.

‘post-quilt’

     Called after the ‘quilt’ support is done.  The following
     information is passed as arguments to the hook: 1.  the
     quilt-support mode (‘addon’ or ‘standalone’); 2.  the directory
     that contains the patch series; 3.  the directory that holds
     quilt’s status information (the ‘.pc’ directory) or the string
     ‘"-nopc-"’ if that directory wasn’t found.

     The ‘hook_com’ parameter is not used.

‘set-branch-format’

     Called before ‘branchformat’ is set.  The only argument to the hook
     is the format that is configured at this point.

     The ‘hook_com’ keys considered are ‘branch’ and ‘revision’.  They
     are set to the values figured out so far by ‘vcs_info’ and any
     change will be used directly when the actual replacement is done.

     If ‘ret’ is set to non-zero, the string in
     ‘${hook_com[branch-replace]}’ will be used unchanged as the ‘%b’
     replacement in the variables set by ‘vcs_info’.

‘set-hgrev-format’

     Called before a ‘hgrevformat’ is set.  The only argument to the
     hook is the format that is configured at this point.

     The ‘hook_com’ keys considered are ‘hash’ and ‘localrev’.  They are
     set to the values figured out so far by ‘vcs_info’ and any change
     will be used directly when the actual replacement is done.

     If ‘ret’ is set to non-zero, the string in
     ‘${hook_com[rev-replace]}’ will be used unchanged as the ‘%i’
     replacement in the variables set by ‘vcs_info’.

‘pre-addon-quilt’

     This hook is used when ‘vcs_info’’s quilt functionality is active
     in “addon” mode (quilt used on top of a real version control
     system).  It is activated right before any quilt specific action is
     taken.

     Setting the ‘ret’ variable in this hook to a non-zero value avoids
     any quilt specific actions from being run at all.

‘set-patch-format’

     This hook is used to control some of the possible expansions in
     ‘patch-format’ and ‘nopatch-format’ styles with patch queue systems
     such as quilt, mqueue and the like.

     This hook is used in the ‘git’, ‘hg’ and ‘quilt’ backends.

     The hook allows the control of the ‘%p’ (‘${hook_com[applied]}’)
     and ‘%u’ (‘${hook_com[unapplied]}’) expansion in all backends that
     use the hook.  With the mercurial backend, the ‘%g’
     (‘${hook_com[guards]}’) expansion is controllable in addition to
     that.

     If ‘ret’ is set to non-zero, the string in
     ‘${hook_com[patch-replace]}’ will be used unchanged instead of an
     expanded format from ‘patch-format’ or ‘nopatch-format’.

     This hook is, in concert with the ‘gen-applied-string’ or
     ‘gen-unapplied-string’ hooks if they are defined, responsible for
     ‘%’-escaping the final ‘patch-format’ value for use in the prompt.
     (See ..  only:: man

          the ‘Oddities’ subsection above

     vcs_info Oddities

     .)

     The ‘quilt’ backend passes to this hook the inputs
     ‘${hook_com[quilt-patches-dir]}’ and, if it has been determined,
     ‘${hook_com[quilt-pc-dir]}’.

‘set-message’

     Called each time before a ‘vcs_info_msg_’N‘_’ message is set.  It
     takes two arguments; the first being the N in the message variable
     name, the second is the currently configured ‘formats’ or
     ‘actionformats’.

     There are a number of ‘hook_com’ keys, that are used here:
     ‘action’, ‘branch’, ‘base’, ‘base-name’, ‘subdir’, ‘staged’,
     ‘unstaged’, ‘revision’, ‘misc’, ‘vcs’ and one ‘miscN’ entry for
     each backend-specific data field (‘N’ starting at zero).  They are
     set to the values figured out so far by ‘vcs_info’ and any change
     will be used directly when the actual replacement is done.

     Since this hook is triggered multiple times (once for each
     configured ‘formats’ or ‘actionformats’), each of the ‘hook_com’
     keys mentioned above (except for the ‘miscN’ entries) has an
     ‘_orig’ counterpart, so even if you changed a value to your liking
     you can still get the original value in the next run.  Changing the
     ‘_orig’ values is probably not a good idea.

     If ‘ret’ is set to non-zero, the string in ‘${hook_com[message]}’
     will be used unchanged as the message by ‘vcs_info’.

If all of this sounds rather confusing, take a look at

vcs_info Examples

and also in the ‘Misc/vcs_info-examples’ file in the Zsh source.  They
contain some explanatory code.


File: zsh.info,  Node: Examples<2>,  Prev: Hooks in vcs_info,  Up: Gathering information from version control systems

25.5.8 Examples
---------------

Don’t use ‘vcs_info’ at all (even though it’s in your prompt):

      zstyle ':vcs_info:*' enable NONE

Disable the backends for ‘bzr’ and ‘svk’:

      zstyle ':vcs_info:*' disable bzr svk

Disable everything ‘but’ ‘bzr’ and ‘svk’:

      zstyle ':vcs_info:*' enable bzr svk

Provide a special formats for ‘git’:

      zstyle ':vcs_info:git:*' formats       ' GIT, BABY! [%b]'
      zstyle ':vcs_info:git:*' actionformats ' GIT ACTION! [%b|%a]'

All ‘%x’ expansion in all sorts of formats (‘formats’, ‘actionformats’,
‘branchformat’, you name it) are done using the ‘zformat’ builtin from
the ‘zsh/zutil’ module.  That means you can do everything with these
‘%x’ items what zformat supports.  In particular, if you want something
that is really long to have a fixed width, like a hash in a mercurial
branchformat, you can do this: ‘%12.12i’.  That’ll shrink the 40
character hash to its 12 leading characters.  The form is actually
‘%’MIN‘.’MAX‘x’.  More is possible.  See *note The zsh/zutil Module: ca.
for details.

Use the quicker ‘bzr’ backend

      zstyle ':vcs_info:bzr:*' use-simple true

If you do use ‘use-simple’, please report if it does
‘the-right-thing[tm]’.

Display the revision number in yellow for ‘bzr’ and ‘svn’:

      zstyle ':vcs_info:(svn|bzr):*' \
             branchformat '%b%%F{yellow}:%r'

The doubled percent sign is explained in

vcs_info Oddities

.

Alternatively, one can use the raw colour codes directly:

      zstyle ':vcs_info:(svn|bzr):*' \
             branchformat '%b%{'${fg[yellow]}'%}:%r'

Normally when a variable is interpolated into a format string, the
variable needs to be ‘%’-escaped.  In this example we skipped that
because we assume the value of ‘${fg[yellow]}’ doesn’t contain any ‘%’
signs.

Make sure you enclose the color codes in ‘%{’…‘%}’ if you want to use
the string provided by ‘vcs_info’ in prompts.

Here is how to print the VCS information as a command (not in a prompt):

      vcsi() { vcs_info interactive; vcs_info_lastmsg }

This way, you can even define different formats for output via
‘vcs_info_lastmsg’ in the ‘‘:vcs_info:*:interactive:*’’ namespace.

Now as promised, some code that uses hooks: say, you’d like to replace
the string ‘svn’ by ‘subversion’ in ‘vcs_info’’s ‘%s’ ‘formats’
replacement.

First, we will tell ‘vcs_info’ to call a function when populating the
message variables with the gathered information:

      zstyle ':vcs_info:*+set-message:*' hooks svn2subversion

Nothing happens.  Which is reasonable, since we didn’t define the actual
function yet.  To see what the hooks subsystem is trying to do, enable
the ‘debug’ style:

      zstyle ':vcs_info:*+*:*' debug true

That should give you an idea what is going on.  Specifically, the
function that we are looking for is ‘+vi-svn2subversion’.  Note, the
‘+vi-’ prefix.  So, everything is in order, just as documented.  When
you are done checking out the debugging output, disable it again:

      zstyle ':vcs_info:*+*:*' debug false

Now, let’s define the function:

      function +vi-svn2subversion() {
          [[ ${hook_com[vcs_orig]} == svn ]] && hook_com[vcs]=subversion
      }

Simple enough.  And it could have even been simpler, if only we had
registered our function in a less generic context.  If we do it only in
the ‘svn’ backend’s context, we don’t need to test which the active
backend is:

      zstyle ':vcs_info:svn+set-message:*' hooks svn2subversion

      function +vi-svn2subversion() {
          hook_com[vcs]=subversion
      }

And finally a little more elaborate example, that uses a hook to create
a customised bookmark string for the ‘hg’ backend.

Again, we start off by registering a function:

      zstyle ':vcs_info:hg+gen-hg-bookmark-string:*' hooks hgbookmarks

And then we define the ‘+vi-hgbookmarks’ function:

      function +vi-hgbookmarks() {
          # The default is to connect all bookmark names by
          # commas. This mixes things up a little.
          # Imagine, there's one type of bookmarks that is
          # special to you. Say, because it's *your* work.
          # Those bookmarks look always like this: "sh/*"
          # (because your initials are sh, for example).
          # This makes the bookmarks string use only those
          # bookmarks. If there's more than one, it
          # concatenates them using commas.
          # The bookmarks returned by \`hg' are available in
          # the function's positional parameters.
          local s="${(Mj:,:)@:#sh/*}"
          # Now, the communication with the code that calls
          # the hook functions is done via the hook_com[]
          # hash. The key at which the \`gen-hg-bookmark-string'
          # hook looks is \`hg-bookmark-string'. So:
          hook_com[hg-bookmark-string]=$s
          # And to signal that we want to use the string we
          # just generated, set the special variable \`ret' to
          # something other than the default zero:
          ret=1
          return 0
      }

Some longer examples and code snippets which might be useful are
available in the examples file located at Misc/vcs_info-examples in the
Zsh source directory.

This concludes our guided tour through zsh’s ‘vcs_info’.


File: zsh.info,  Node: Prompt Themes,  Next: ZLE Functions,  Prev: Gathering information from version control systems,  Up: User Contributions

25.6 Prompt Themes
==================

* Menu:

* Installation: Installation<3>.
* Theme Selection::
* Utility Themes::
* Writing Themes::


File: zsh.info,  Node: Installation<3>,  Next: Theme Selection,  Up: Prompt Themes

25.6.1 Installation
-------------------

You should make sure all the functions from the ‘Functions/Prompts’
directory of the source distribution are available; they all begin with
the string ‘prompt_’ except for the special function ‘promptinit’.  You
also need the ‘colors’ and ‘add-zsh-hook’ functions from
‘Functions/Misc’.  All these functions may already be installed on your
system; if not, you will need to find them and copy them.  The directory
should appear as one of the elements of the ‘fpath’ array (this should
already be the case if they were installed), and at least the function
‘promptinit’ should be autoloaded; it will autoload the rest.  Finally,
to initialize the use of the system you need to call the ‘promptinit’
function.  The following code in your ‘.zshrc’ will arrange for this;
assume the functions are stored in the directory ‘~/myfns’:

      fpath=(~/myfns $fpath)
      autoload -U promptinit
      promptinit


File: zsh.info,  Node: Theme Selection,  Next: Utility Themes,  Prev: Installation<3>,  Up: Prompt Themes

25.6.2 Theme Selection
----------------------

Use the ‘prompt’ command to select your preferred theme.  This command
may be added to your ‘.zshrc’ following the call to ‘promptinit’ in
order to start zsh with a theme already selected.

‘prompt’ [ ‘-c’ | ‘-l’ ]

‘prompt’ [ ‘-p’ | ‘-h’ ] [ THEME … ]

‘prompt’ [ ‘-s’ ] THEME [ ARG … ]

     Set or examine the prompt theme.  With no options and a THEME
     argument, the theme with that name is set as the current theme.
     The available themes are determined at run time; use the ‘-l’
     option to see a list.  The special THEME ‘random’ selects at random
     one of the available themes and sets your prompt to that.

     In some cases the THEME may be modified by one or more arguments,
     which should be given after the theme name.  See the help for each
     theme for descriptions of these arguments.

     Options are:

     ‘-c’

          Show the currently selected theme and its parameters, if any.

     ‘-l’

          List all available prompt themes.

     ‘-p’

          Preview the theme named by THEME, or all themes if no THEME is
          given.

     ‘-h’

          Show help for the theme named by THEME, or for the ‘prompt’
          function if no THEME is given.

     ‘-s’

          Set THEME as the current theme and save state.

‘prompt_’THEME‘_setup’

     Each available THEME has a setup function which is called by the
     ‘prompt’ function to install that theme.  This function may define
     other functions as necessary to maintain the prompt, including
     functions used to preview the prompt or provide help for its use.
     You should not normally call a theme’s setup function directly.


File: zsh.info,  Node: Utility Themes,  Next: Writing Themes,  Prev: Theme Selection,  Up: Prompt Themes

25.6.3 Utility Themes
---------------------

‘prompt off’

     The theme ‘off’ sets all the prompt variables to minimal values
     with no special effects.

‘prompt default’

     The theme ‘default’ sets all prompt variables to the same state as
     if an interactive zsh was started with no initialization files.

‘prompt restore’

     The special theme ‘restore’ erases all theme settings and sets
     prompt variables to their state before the first time the ‘prompt’
     function was run, provided each theme has properly defined its
     cleanup (see below).

     Note that you can undo ‘prompt off’ and ‘prompt default’ with
     ‘prompt restore’, but a second restore does not undo the first.


File: zsh.info,  Node: Writing Themes,  Prev: Utility Themes,  Up: Prompt Themes

25.6.4 Writing Themes
---------------------

The first step for adding your own theme is to choose a name for it, and
create a file ‘prompt_:var:`name`_setup’ in a directory in your ‘fpath’,
such as ‘~/myfns’ in the example above.  The file should at minimum
contain assignments for the prompt variables that your theme wishes to
modify.  By convention, themes use ‘PS1’, ‘PS2’, ‘RPS1’, etc., rather
than the longer ‘PROMPT’ and ‘RPROMPT’.

The file is autoloaded as a function in the current shell context, so it
may contain any necessary commands to customize your theme, including
defining additional functions.  To make some complex tasks easier, your
setup function may also do any of the following:

Assign ‘prompt_opts’

     The array ‘prompt_opts’ may be assigned any of ‘"bang"’, ‘"cr"’,
     ‘"percent"’, ‘"sp"’, and/or ‘"subst"’ as values.  The corresponding
     setopts (‘promptbang’, etc.)  are turned on, all other
     prompt-related options are turned off.  The ‘prompt_opts’ array
     preserves setopts even beyond the scope of ‘localoptions’, should
     your function need that.

Modify hooks

     Use of ‘add-zsh-hook’ and ‘add-zle-hook-widget’ is recommended (see
     *note Manipulating Hook Functions: 1a7.).  All hooks that follow
     the naming pattern ‘prompt_’THEME‘_’HOOK are automatically removed
     when the prompt theme changes or is disabled.

Declare cleanup

     If your function makes any other changes that should be undone when
     the theme is disabled, your setup function may call

           prompt_cleanup COMMAND

     where COMMAND should be suitably quoted.  If your theme is ever
     disabled or replaced by another, COMMAND is executed with ‘eval’.
     You may declare more than one such cleanup hook.

Define preview

     Define or autoload a function ‘prompt_’NAME‘_preview’ to display a
     simulated version of your prompt.  A simple default previewer is
     defined by ‘promptinit’ for themes that do not define their own.
     This preview function is called by ‘prompt -p’.

Provide help

     Define or autoload a function ‘prompt_’NAME‘_help’ to display
     documentation or help text for your theme.  This help function is
     called by ‘prompt -h’.


File: zsh.info,  Node: ZLE Functions,  Next: Exception Handling,  Prev: Prompt Themes,  Up: User Contributions

25.7 ZLE Functions
==================

* Menu:

* Widgets::
* Utility Functions: Utility Functions<2>.
* Styles: Styles<2>.


File: zsh.info,  Node: Widgets,  Next: Utility Functions<2>,  Up: ZLE Functions

25.7.1 Widgets
--------------

These functions all implement user-defined ZLE widgets (see *note
User-Defined Widgets: da.) which can be bound to keystrokes in
interactive shells.  To use them, your ‘.zshrc’ should contain lines of
the form

      autoload FUNCTION
      zle -N FUNCTION

followed by an appropriate ‘bindkey’ command to associate the function
with a key sequence.  Suggested bindings are described below.

bash-style word functions

     If you are looking for functions to implement moving over and
     editing words in the manner of bash, where only alphanumeric
     characters are considered word characters, you can use the
     functions described in the next section.  The following is
     sufficient:

           autoload -U select-word-style
           select-word-style bash

‘forward-word-match’, ‘backward-word-match’

‘kill-word-match’, ‘backward-kill-word-match’

‘transpose-words-match’, ‘capitalize-word-match’

‘up-case-word-match’, ‘down-case-word-match’

‘delete-whole-word-match’, ‘select-word-match’

‘select-word-style’, ‘match-word-context’, ‘match-words-by-style’

     The first eight ‘-match’ functions are drop-in replacements for the
     builtin widgets without the suffix.  By default they behave in a
     similar way.  However, by the use of styles and the function
     ‘select-word-style’, the way words are matched can be altered.
     ‘select-word-match’ is intended to be used as a text object in vi
     mode but with custom word styles.  For comparison, the widgets
     described in *note Text Objects: e1. use fixed definitions of
     words, compatible with the ‘vim’ editor.

     The simplest way of configuring the functions is to use
     ‘select-word-style’, which can either be called as a normal
     function with the appropriate argument, or invoked as a
     user-defined widget that will prompt for the first character of the
     word style to be used.  The first time it is invoked, the first
     eight ‘-match’ functions will automatically replace the builtin
     versions, so they do not need to be loaded explicitly.

     The word styles available are as follows.  Only the first character
     is examined.

     ‘bash’

          Word characters are alphanumeric characters only.

     ‘normal’

          As in normal shell operation: word characters are alphanumeric
          characters plus any characters present in the string given by
          the parameter ‘$WORDCHARS’.

     ‘shell’

          Words are complete shell command arguments, possibly including
          complete quoted strings, or any tokens special to the shell.

     ‘whitespace’

          Words are any set of characters delimited by whitespace.

     ‘default’

          Restore the default settings; this is usually the same as
          ‘normal’.

     All but ‘default’ can be input as an upper case character, which
     has the same effect but with subword matching turned on.  In this
     case, words with upper case characters are treated specially: each
     separate run of upper case characters, or an upper case character
     followed by any number of other characters, is considered a word.
     The style ‘subword-range’ can supply an alternative character range
     to the default ‘[:upper:]’; the value of the style is treated as
     the contents of a ‘[’…‘]’ pattern (note that the outer brackets
     should not be supplied, only those surrounding named ranges).

     More control can be obtained using the ‘zstyle’ command, as
     described in *note The zsh/zutil Module: ca.  Each style is looked
     up in the context ‘:zle:’WIDGET where WIDGET is the name of the
     user-defined widget, not the name of the function implementing it,
     so in the case of the definitions supplied by ‘select-word-style’
     the appropriate contexts are ‘:zle:forward-word’, and so on.  The
     function ‘select-word-style’ itself always defines styles for the
     context ‘:zle:*’ which can be overridden by more specific (longer)
     patterns as well as explicit contexts.

     The style ‘word-style’ specifies the rules to use.  This may have
     the following values.

     ‘normal’

          Use the standard shell rules, i.e.  alphanumerics and
          ‘$WORDCHARS’, unless overridden by the styles ‘word-chars’ or
          ‘word-class’.

     ‘specified’

          Similar to ‘normal’, but ‘only’ the specified characters, and
          not also alphanumerics, are considered word characters.

     ‘unspecified’

          The negation of specified.  The given characters are those
          which will ‘not’ be considered part of a word.

     ‘shell’

          Words are obtained by using the syntactic rules for generating
          shell command arguments.  In addition, special tokens which
          are never command arguments such as ‘()’ are also treated as
          words.

     ‘whitespace’

          Words are whitespace-delimited strings of characters.

     The first three of those rules usually use ‘$WORDCHARS’, but the
     value in the parameter can be overridden by the style ‘word-chars’,
     which works in exactly the same way as ‘$WORDCHARS’.  In addition,
     the style ‘word-class’ uses character class syntax to group
     characters and takes precedence over ‘word-chars’ if both are set.
     The ‘word-class’ style does not include the surrounding brackets of
     the character class; for example, ‘-:[:alnum:]’ is a valid
     ‘word-class’ to include all alphanumerics plus the characters ‘-’
     and ‘:’.  Be careful including ‘]’, ‘^’ and ‘-’ as these are
     special inside character classes.

     ‘word-style’ may also have ‘-subword’ appended to its value to turn
     on subword matching, as described above.

     The style ‘skip-chars’ is mostly useful for ‘transpose-words’ and
     similar functions.  If set, it gives a count of characters starting
     at the cursor position which will not be considered part of the
     word and are treated as space, regardless of what they actually
     are.  For example, if

           zstyle ':zle:transpose-words' skip-chars 1

     has been set, and ‘transpose-words-match’ is called with the cursor
     on the X of ‘foo’X‘bar’, where X can be any character, then the
     resulting expression is ‘bar’X‘foo’.

     Finer grained control can be obtained by setting the style
     ‘word-context’ to an array of pairs of entries.  Each pair of
     entries consists of a PATTERN and a SUBCONTEXT.  The shell argument
     the cursor is on is matched against each PATTERN in turn until one
     matches; if it does, the context is extended by a colon and the
     corresponding SUBCONTEXT.  Note that the test is made against the
     original word on the line, with no stripping of quotes.  Special
     handling is done between words: the current context is examined and
     if it contains the string ‘between’ the word is set to a single
     space; else if it is contains the string ‘back’, the word before
     the cursor is considered, else the word after cursor is considered.
     Some examples are given below.

     The style ‘skip-whitespace-first’ is only used with the
     ‘forward-word’ widget.  If it is set to true, then ‘forward-word’
     skips any non-word-characters, followed by any non-word-characters:
     this is similar to the behaviour of other word-orientated widgets,
     and also that used by other editors, however it differs from the
     standard zsh behaviour.  When using ‘select-word-style’ the widget
     is set in the context ‘:zle:*’ to ‘true’ if the word style is
     ‘bash’ and ‘false’ otherwise.  It may be overridden by setting it
     in the more specific context ‘:zle:forward-word*’.

     It is possible to create widgets with specific behaviour by
     defining a new widget implemented by the appropriate generic
     function, then setting a style for the context of the specific
     widget.  For example, the following defines a widget
     ‘backward-kill-space-word’ using ‘backward-kill-word-match’, the
     generic widget implementing ‘backward-kill-word’ behaviour, and
     ensures that the new widget always implements space-delimited
     behaviour.

           zle -N backward-kill-space-word backward-kill-word-match
           zstyle :zle:backward-kill-space-word word-style space

     The widget ‘backward-kill-space-word’ can now be bound to a key.

     Here are some further examples of use of the styles, actually taken
     from the simplified interface in ‘select-word-style’:

           zstyle ':zle:*' word-style standard
           zstyle ':zle:*' word-chars ''

     Implements bash-style word handling for all widgets, i.e.  only
     alphanumerics are word characters; equivalent to setting the
     parameter ‘WORDCHARS’ empty for the given context.

           style ':zle:*kill*' word-style space

     Uses space-delimited words for widgets with the word ‘kill’ in the
     name.  Neither of the styles ‘word-chars’ nor ‘word-class’ is used
     in this case.

     Here are some examples of use of the ‘word-context’ style to extend
     the context.

           zstyle ':zle:*' word-context \
                  "*/*" filename "[[:space:]]" whitespace
           zstyle ':zle:transpose-words:whitespace' word-style shell
           zstyle ':zle:transpose-words:filename' word-style normal
           zstyle ':zle:transpose-words:filename' word-chars ''

     This provides two different ways of using ‘transpose-words’
     depending on whether the cursor is on whitespace between words or
     on a filename, here any word containing a ‘/’.  On whitespace,
     complete arguments as defined by standard shell rules will be
     transposed.  In a filename, only alphanumerics will be transposed.
     Elsewhere, words will be transposed using the default style for
     ‘:zle:transpose-words’.

     The word matching and all the handling of ‘zstyle’ settings is
     actually implemented by the function ‘match-words-by-style’.  This
     can be used to create new user-defined widgets.  The calling
     function should set the local parameter ‘curcontext’ to
     ‘:zle:’WIDGET, create the local parameter ‘matched_words’ and call
     ‘match-words-by-style’ with no arguments.  On return,
     ‘matched_words’ will be set to an array with the elements: (1) the
     start of the line (2) the word before the cursor (3) any non-word
     characters between that word and the cursor (4) any non-word
     character at the cursor position plus any remaining non-word
     characters before the next word, including all characters specified
     by the ‘skip-chars’ style, (5) the word at or following the cursor
     (6) any non-word characters following that word (7) the remainder
     of the line.  Any of the elements may be an empty string; the
     calling function should test for this to decide whether it can
     perform its function.

     If the variable ‘matched_words’ is defined by the caller to
     ‘match-words-by-style’ as an associative array (‘local -A
     matched_words’), then the seven values given above should be
     retrieved from it as elements named ‘start’, ‘word-before-cursor’,
     ‘ws-before-cursor’, ‘ws-after-cursor’, ‘word-after-cursor’,
     ‘ws-after-word’, and ‘end’.  In addition the element
     ‘is-word-start’ is 1 if the cursor is on the start of a word or
     subword, or on white space before it (the cases can be
     distinguished by testing the ‘ws-after-cursor’ element) and 0
     otherwise.  This form is recommended for future compatibility.

     It is possible to pass options with arguments to
     ‘match-words-by-style’ to override the use of styles.  The options
     are:

     ‘-w’

          WORD-STYLE

     ‘-s’

          SKIP-CHARS

     ‘-c’

          WORD-CLASS

     ‘-C’

          WORD-CHARS

     ‘-r’

          SUBWORD-RANGE

     For example, ‘match-words-by-style -w shell -c 0’ may be used to
     extract the command argument around the cursor.

     The ‘word-context’ style is implemented by the function
     ‘match-word-context’.  This should not usually need to be called
     directly.

‘bracketed-paste-magic’

     The ‘bracketed-paste’ widget (see *note Miscellaneous: d6.) inserts
     pasted text literally into the editor buffer rather than interpret
     it as keystrokes.  This disables some common usages where the
     self-insert widget is replaced in order to accomplish some extra
     processing.  An example is the contributed ‘url-quote-magic’ widget
     described below.

     The ‘bracketed-paste-magic’ widget is meant to replace
     ‘bracketed-paste’ with a wrapper that re-enables these self-insert
     actions, and other actions as selected by zstyles.  Therefore this
     widget is installed with

           autoload -Uz bracketed-paste-magic
           zle -N bracketed-paste bracketed-paste-magic

     Other than enabling some widget processing, ‘bracketed-paste-magic’
     attempts to replicate ‘bracketed-paste’ as faithfully as possible.

     The following zstyles may be set to control processing of pasted
     text.  All are looked up in the context ‘:bracketed-paste-magic’.

     ‘active-widgets’

          A list of patterns matching widget names that should be
          activated during the paste.  All other key sequences are
          processed as self-insert-unmeta.  The default is ‘self-*’ so
          any user-defined widgets named with that prefix are active
          along with the builtin self-insert.

          If this style is not set (explicitly deleted) or set to an
          empty value, no widgets are active and the pasted text is
          inserted literally.  If the value includes ‘undefined-key’,
          any unknown sequences are discarded from the pasted text.

     ‘inactive-keys’

          The inverse of ‘active-widgets’, a list of key sequences that
          always use ‘self-insert-unmeta’ even when bound to an active
          widget.  Note that this is a list of literal key sequences,
          not patterns.

     ‘paste-init’

          A list of function names, called in widget context (but not as
          widgets).  The functions are called in order until one of them
          returns a non-zero status.  The parameter ‘PASTED’ contains
          the initial state of the pasted text.  All other ZLE
          parameters such as ‘BUFFER’ have their normal values and
          side-effects, and full history is available, so for example
          ‘paste-init’ functions may move words from ‘BUFFER’ into
          ‘PASTED’ to make those words visible to the ‘active-widgets’.

          A non-zero return from a ‘paste-init’ function does ‘not’
          prevent the paste itself from proceeding.

          Loading ‘bracketed-paste-magic’ defines
          ‘backward-extend-paste’, a helper function for use in
          ‘paste-init’.

                zstyle :bracketed-paste-magic paste-init \
                       backward-extend-paste

          When a paste would insert into the middle of a word or append
          text to a word already on the line, ‘backward-extend-paste’
          moves the prefix from ‘LBUFFER’ into ‘PASTED’ so that the
          ‘active-widgets’ see the full word so far.  This may be useful
          with ‘url-quote-magic’.

     ‘paste-finish’

          Another list of function names called in order until one
          returns non-zero.  These functions are called ‘after’ the
          pasted text has been processed by the ‘active-widgets’, but
          ‘before’ it is inserted into ‘BUFFER’.  ZLE parameters have
          their normal values and side-effects.

          A non-zero return from a ‘paste-finish’ function does ‘not’
          prevent the paste itself from proceeding.

          Loading ‘bracketed-paste-magic’ also defines ‘quote-paste’, a
          helper function for use in ‘paste-finish’.

                zstyle :bracketed-paste-magic paste-finish \
                       quote-paste
                zstyle :bracketed-paste-magic:finish quote-style \
                       qqq

          When the pasted text is inserted into ‘BUFFER’, it is quoted
          per the ‘quote-style’ value.  To forcibly turn off the
          built-in numeric prefix quoting of ‘bracketed-paste’, use:

                zstyle :bracketed-paste-magic:finish quote-style \
                       none

     ‘Important:’ During ‘active-widgets’ processing of the paste (after
     ‘paste-init’ and before ‘paste-finish’), ‘BUFFER’ starts empty and
     history is restricted, so cursor motions, etc., may not pass
     outside of the pasted content.  Text assigned to ‘BUFFER’ by the
     active widgets is copied back into ‘PASTED’ before ‘paste-finish’.

‘bracketed-paste-url-magic’

     This widget is a simpler version of using ‘bracketed-paste-magic’
     to enable ‘quote-url-magic’.  Rather than re-interpreting
     everything as keystrokes, it simply handles quoting of pasted urls
     itself, and all other text is handled like the default
     bracketed-paste widget.

     It limits the quoting to pastes that consist of a single url, but
     you can also enable or disable quoting explicitly for a paste by
     setting NUMERIC to 1 or 2 respectively (ie, by pressing alt-1 or
     alt-2 before pasting).

     It is also possible to customize the list of schemas used to decide
     if something is a url by setting the ‘schema’ style in the
     ‘:bracketed-paste-url-magic’ context, for example:

           zstyle :bracketed-paste-url-magic schema http:// myspecialschema:

     The default list of schemas is ‘http:// https:// ftp:// ftps://
     file:// ssh:// sftp:// magnet:’.

     The widget itself is installed in a similar way as
     ‘bracketed-paste-magic’ above, by

           autoload -Uz bracketed-paste-url-magic
           zle -N bracketed-paste bracketed-paste-url-magic

‘copy-earlier-word’

     This widget works like a combination of ‘insert-last-word’ and
     ‘copy-prev-shell-word’.  Repeated invocations of the widget
     retrieve earlier words on the relevant history line.  With a
     numeric argument N, insert the Nth word from the history line; N
     may be negative to count from the end of the line.

     If ‘insert-last-word’ has been used to retrieve the last word on a
     previous history line, repeated invocations will replace that word
     with earlier words from the same line.

     Otherwise, the widget applies to words on the line currently being
     edited.  The ‘widget’ style can be set to the name of another
     widget that should be called to retrieve words.  This widget must
     accept the same three arguments as ‘insert-last-word’.

‘cycle-completion-positions’

     After inserting an unambiguous string into the command line, the
     new function based completion system may know about multiple places
     in this string where characters are missing or differ from at least
     one of the possible matches.  It will then place the cursor on the
     position it considers to be the most interesting one, i.e.  the one
     where one can disambiguate between as many matches as possible with
     as little typing as possible.

     This widget allows the cursor to be easily moved to the other
     interesting spots.  It can be invoked repeatedly to cycle between
     all positions reported by the completion system.

‘delete-whole-word-match’

     This is another function which works like the ‘-match’ functions
     described immediately above, i.e.  using styles to decide the word
     boundaries.  However, it is not a replacement for any existing
     function.

     The basic behaviour is to delete the word around the cursor.  There
     is no numeric argument handling; only the single word around the
     cursor is considered.  If the widget contains the string ‘kill’,
     the removed text will be placed in the cutbuffer for future
     yanking.  This can be obtained by defining ‘kill-whole-word-match’
     as follows:

           zle -N kill-whole-word-match delete-whole-word-match

     and then binding the widget ‘kill-whole-word-match’.

‘up-line-or-beginning-search’, ‘down-line-or-beginning-search’

     These widgets are similar to the builtin functions
     ‘up-line-or-search’ and ‘down-line-or-search’: if in a multiline
     buffer they move up or down within the buffer, otherwise they
     search for a history line matching the start of the current line.
     In this case, however, they search for a line which matches the
     current line up to the current cursor position, in the manner of
     ‘history-beginning-search-backward’ and ‘-forward’, rather than the
     first word on the line.

‘edit-command-line’

     Edit the command line using your visual editor, as in ‘ksh’.

           bindkey -M vicmd v edit-command-line

     The editor to be used can also be specified using the ‘editor’
     style in the context of the widget.  It is specified as an array of
     command and arguments:

           zstyle :zle:edit-command-line editor gvim -f

‘expand-absolute-path’

     Expand the file name under the cursor to an absolute path,
     resolving symbolic links.  Where possible, the initial path segment
     is turned into a named directory or reference to a user’s home
     directory.

‘history-search-end’

     This function implements the widgets
     ‘history-beginning-search-backward-end’ and
     ‘history-beginning-search-forward-end’.  These commands work by
     first calling the corresponding builtin widget (see *note History
     Control: de.) and then moving the cursor to the end of the line.
     The original cursor position is remembered and restored before
     calling the builtin widget a second time, so that the same search
     is repeated to look farther through the history.

     Although you ‘autoload’ only one function, the commands to use it
     are slightly different because it implements two widgets.

           zle -N history-beginning-search-backward-end \
                  history-search-end
           zle -N history-beginning-search-forward-end \
                  history-search-end
           bindkey '\e^P' history-beginning-search-backward-end
           bindkey '\e^N' history-beginning-search-forward-end

‘history-beginning-search-menu’

     This function implements yet another form of history searching.
     The text before the cursor is used to select lines from the
     history, as for ‘history-beginning-search-backward’ except that all
     matches are shown in a numbered menu.  Typing the appropriate
     digits inserts the full history line.  Note that leading zeroes
     must be typed (they are only shown when necessary for removing
     ambiguity).  The entire history is searched; there is no
     distinction between forwards and backwards.

     With a numeric argument, the search is not anchored to the start of
     the line; the string typed by the use may appear anywhere in the
     line in the history.

     If the widget name contains ‘-end’ the cursor is moved to the end
     of the line inserted.  If the widget name contains ‘-space’ any
     space in the text typed is treated as a wildcard and can match
     anything (hence a leading space is equivalent to giving a numeric
     argument).  Both forms can be combined, for example:

           zle -N history-beginning-search-menu-space-end \
                  history-beginning-search-menu

‘history-pattern-search’

     The function ‘history-pattern-search’ implements widgets which
     prompt for a pattern with which to search the history backwards or
     forwards.  The pattern is in the usual zsh format, however the
     first character may be ‘^’ to anchor the search to the start of the
     line, and the last character may be ‘$’ to anchor the search to the
     end of the line.  If the search was not anchored to the end of the
     line the cursor is positioned just after the pattern found.

     The commands to create bindable widgets are similar to those in the
     example immediately above:

           autoload -U history-pattern-search
           zle -N history-pattern-search-backward history-pattern-search
           zle -N history-pattern-search-forward history-pattern-search

‘incarg’

     This widget allows you to increment integers on the current line.
     In addition to decimals, it can handle hexadecimals prefixed with
     ‘0x’, binaries with ‘0b’, and octals with ‘0o’.

     By default, the target integer will be incremented by one.  With a
     numeric argument, the integer is incremented by the amount of the
     argument.  The shell parameter ‘incarg’ may be set to change the
     default increment to something other than one.

     The behavior of this widget changes depending on the widget name.

     When the widget is named ‘incarg’, the widget will increment an
     integer placed under the cursor placed or just to the left of it.
     ‘decarg’, on the other hand, decrements the integer.  When the name
     is prefixed with ‘vi’, the cursor will jump to the nearest integer
     after the cursor before incrementing it.  The ‘vi’ prefix can also
     be combined with a ‘backward-’ prefix to make the widget search
     backwards for numbers.

     There’s also a ‘sync-’ prefix that can be added to the widget name.
     This variant is used for creating a sequence of numbers on split
     terminals with synchronized key input.  The first pane won’t
     increment the integer at all, but each pane after that will have
     the integer incremented once more than the previous pane.  It
     currently supports tmux and iTerm2.

     The prefixes ‘vi’, ‘backward-’, and ‘sync-’ can be combined, for
     example, into ‘vim-sync-’ or ‘vim-backward-sync-’.  The ‘vi’ prefix
     needs to be at the very beginning.

           bindkey '^X+' incarg

‘incremental-complete-word’

     This allows incremental completion of a word.  After starting this
     command, a list of completion choices can be shown after every
     character you type, which you can delete with ‘^H’ or ‘DEL’.
     Pressing return accepts the completion so far and returns you to
     normal editing (that is, the command line is ‘not’ immediately
     executed).  You can hit ‘TAB’ to do normal completion, ‘^G’ to
     abort back to the state when you started, and ‘^D’ to list the
     matches.

     This works only with the new function based completion system.

           bindkey '^Xi' incremental-complete-word

‘insert-composed-char’

     This function allows you to compose characters that don’t appear on
     the keyboard to be inserted into the command line.  The command is
     followed by two keys corresponding to ASCII characters (there is no
     prompt).  For accented characters, the two keys are a base
     character followed by a code for the accent, while for other
     special characters the two characters together form a mnemonic for
     the character to be inserted.  The two-character codes are a subset
     of those given by RFC 1345 (see for example
     ‘http://www.faqs.org/rfcs/rfc1345.html’).

     The function may optionally be followed by up to two characters
     which replace one or both of the characters read from the keyboard;
     if both characters are supplied, no input is read.  For example,
     ‘insert-composed-char a:’ can be used within a widget to insert an
     a with umlaut into the command line.  This has the advantages over
     use of a literal character that it is more portable.

     For best results zsh should have been built with support for
     multibyte characters (configured with ‘--enable-multibyte’);
     however, the function works for the limited range of characters
     available in single-byte character sets such as ISO-8859-1.

     The character is converted into the local representation and
     inserted into the command line at the cursor position.  (The
     conversion is done within the shell, using whatever facilities the
     C library provides.)  With a numeric argument, the character and
     its code are previewed in the status line

     The function may be run outside zle in which case it prints the
     character (together with a newline) to standard output.  Input is
     still read from keystrokes.

     See ‘insert-unicode-char’ for an alternative way of inserting
     Unicode characters using their hexadecimal character number.

     The set of accented characters is reasonably complete up to Unicode
     character U+0180, the set of special characters less so.  However,
     it is very sporadic from that point.  Adding new characters is
     easy, however; see the function ‘define-composed-chars’.  Please
     send any additions to ‘zsh-workers@zsh.org’.

     The codes for the second character when used to accent the first
     are as follows.  Note that not every character can take every
     accent.

     ‘!’

          Grave.

     ‘'’

          Acute.

     ‘>’

          Circumflex.

     ‘?’

          Tilde.  (This is not ‘~’ as RFC 1345 does not assume that
          character is present on the keyboard.)

     ‘-’

          Macron.  (A horizontal bar over the base character.)

     ‘(’

          Breve.  (A shallow dish shape over the base character.)

     ‘.’

          Dot above the base character, or in the case of ‘i’ no dot, or
          in the case of ‘L’ and ‘l’ a centered dot.

     ‘:’

          Diaeresis (Umlaut).

     ‘c’

          Cedilla.

     ‘_’

          Underline, however there are currently no underlined
          characters.

     ‘/’

          Stroke through the base character.

     ‘"’

          Double acute (only supported on a few letters).

     ‘;’

          Ogonek.  (A little forward facing hook at the bottom right of
          the character.)

     ‘<’

          Caron.  (A little v over the letter.)

     ‘0’

          Circle over the base character.

     ‘2’

          Hook over the base character.

     ‘9’

          Horn over the base character.

     The most common characters from the Arabic, Cyrillic, Greek and
     Hebrew alphabets are available; consult RFC 1345 for the
     appropriate sequences.  In addition, a set of two letter codes not
     in RFC 1345 are available for the double-width characters
     corresponding to ASCII characters from ‘!’ to ‘~’ (0x21 to 0x7e) by
     preceding the character with ‘^’, for example ‘^A’ for a
     double-width ‘A’.

     The following other two-character sequences are understood.

     ASCII characters

          These are already present on most keyboards:

          ‘<(’

               Left square bracket

          ‘//’

               Backslash (solidus)

          ‘)>’

               Right square bracket

          ‘(!’

               Left brace (curly bracket)

          ‘!!’

               Vertical bar (pipe symbol)

          ‘!)’

               Right brace (curly bracket)

          ‘'?’

               Tilde

     Special letters

          Characters found in various variants of the Latin alphabet:

          ‘ss’

               Eszett (scharfes S)

          ‘D-’, ‘d-’

               Eth

          ‘TH’, ‘th’

               Thorn

          ‘kk’

               Kra

          ‘'n’

               ‘n

          ‘NG’, ‘ng’

               Ng

          ‘OI’, ‘oi’

               Oi

          ‘yr’

               yr

          ‘ED’

               ezh

     Currency symbols

          ‘Ct’

               Cent

          ‘Pd’

               Pound sterling (also lira and others)

          ‘Cu’

               Currency

          ‘Ye’

               Yen

          ‘Eu’

               Euro (N.B. not in RFC 1345)

     Punctuation characters

          References to “right” quotes indicate the shape (like a 9
          rather than 6) rather than their grammatical use.  (For
          example, a “right” low double quote is used to open quotations
          in German.)

          ‘!I’

               Inverted exclamation mark

          ‘BB’

               Broken vertical bar

          ‘SE’

               Section

          ‘Co’

               Copyright

          ‘-a’

               Spanish feminine ordinal indicator

          ‘<<’

               Left guillemet

          ‘--’

               Soft hyphen

          ‘Rg’

               Registered trade mark

          ‘PI’

               Pilcrow (paragraph)

          ‘-o’

               Spanish masculine ordinal indicator

          ‘>>’

               Right guillemet

          ‘?I’

               Inverted question mark

          ‘-1’

               Hyphen

          ‘-N’

               En dash

          ‘-M’

               Em dash

          ‘-3’

               Horizontal bar

          ‘:3’

               Vertical ellipsis

          ‘.3’

               Horizontal midline ellipsis

          ‘!2’

               Double vertical line

          ‘=2’

               Double low line

          ‘'6’

               Left single quote

          ‘'9’

               Right single quote

          ‘.9’

               “Right” low quote

          ‘9'’

               Reversed “right” quote

          ‘"6’

               Left double quote

          ‘"9’

               Right double quote

          ‘:9’

               “Right” low double quote

          ‘9"’

               Reversed “right” double quote

          ‘/-’

               Dagger

          ‘/=’

               Double dagger

     Mathematical symbols

          ‘DG’

               Degree

          ‘-2’, ‘+-’, ‘-+’

                  - sign, +/- sign, -/+ sign

          ‘2S’

               Superscript 2

          ‘3S’

               Superscript 3

          ‘1S’

               Superscript 1

          ‘My’

               Micro

          ‘.M’

               Middle dot

          ‘14’

               Quarter

          ‘12’

               Half

          ‘34’

               Three quarters

          ‘*X’

               Multiplication

          ‘-:’

               Division

          ‘%0’

               Per mille

          ‘FA’, ‘TE’, ‘/0’

               For all, there exists, empty set

          ‘dP’, ‘DE’, ‘NB’

               Partial derivative, delta (increment), del (nabla)

          ‘(-’, ‘-)’

               Element of, contains

          ‘*P’, ‘+Z’

               Product, sum

          ‘*-’, ‘Ob’, ‘Sb’

               Asterisk, ring, bullet

          ‘RT’, ‘0(’, ‘00’

               Root sign, proportional to, infinity

     Other symbols

          ‘cS’, ‘cH’, ‘cD’, ‘cC’

               Card suits: spades, hearts, diamonds, clubs

          ‘Md’, ‘M8’, ‘M2’, ‘Mb’, ‘Mx’, ‘MX’

               Musical notation: crotchet (quarter note), quaver (eighth
               note), semiquavers (sixteenth notes), flag sign, natural
               sign, sharp sign

          ‘Fm’, ‘Ml’

               Female, male

     Accents on their own

          ‘'>’

               Circumflex (same as caret, ‘^’)

          ‘'!’

               Grave (same as backtick, >>‘‘<<>>‘‘<<)

          ‘',’

               Cedilla

          ‘':’

               Diaeresis (Umlaut)

          ‘'m’

               Macron

          ‘''’

               Acute

‘insert-files’

     This function allows you type a file pattern, and see the results
     of the expansion at each step.  When you hit return, all expansions
     are inserted into the command line.

           bindkey ^Xf' insert-files

‘insert-unicode-char’

     When first executed, the user inputs a set of hexadecimal digits.
     This is terminated with another call to ‘insert-unicode-char’.  The
     digits are then turned into the corresponding Unicode character.
     For example, if the widget is bound to ‘^XU’, the character
     sequence ‘^XU 4 c ^XU’ inserts ‘L’ (Unicode U+004c).

     See ‘insert-composed-char’ for a way of inserting characters using
     a two-character mnemonic.

‘narrow-to-region’ [ ‘-p’ PRE ] [ ‘-P’ POST ]

     [ ‘-S’ STATEPM | ‘-R’ STATEPM | [ ‘-l’ LBUFVAR ] [ ‘-r’ RBUFVAR ] ]

     [ ‘-n’ ] [ START END ]

‘narrow-to-region-invisible’

     Narrow the editable portion of the buffer to the region between the
     cursor and the mark, which may be in either order.  The region may
     not be empty.

     ‘narrow-to-region’ may be used as a widget or called as a function
     from a user-defined widget; by default, the text outside the
     editable area remains visible.  A ‘recursive-edit’ is performed and
     the original widening status is then restored.  Various options and
     arguments are available when it is called as a function.

     The options ‘-p’ PRETEXT and ‘-P’ POSTTEXT may be used to replace
     the text before and after the display for the duration of the
     function; either or both may be an empty string.

     If the option ‘-n’ is also given, PRETEXT or POSTTEXT will only be
     inserted if there is text before or after the region respectively
     which will be made invisible.

     Two numeric arguments may be given which will be used instead of
     the cursor and mark positions.

     The option ‘-S’ STATEPM is used to narrow according to the other
     options while saving the original state in the parameter with name
     STATEPM, while the option ‘-R’ STATEPM is used to restore the state
     from the parameter; note in both cases the ‘name’ of the parameter
     is required.  In the second case, other options and arguments are
     irrelevant.  When this method is used, no ‘recursive-edit’ is
     performed; the calling widget should call this function with the
     option ‘-S’, perform its own editing on the command line or pass
     control to the user via ‘zle recursive-edit’, then call this
     function with the option ‘-R’.  The argument STATEPM must be a
     suitable name for an ordinary parameter, except that parameters
     beginning with the prefix ‘_ntr_’ are reserved for use within
     ‘narrow-to-region’.  Typically the parameter will be local to the
     calling function.

     The options ‘-l’ LBUFVAR and ‘-r’ RBUFVAR may be used to specify
     parameters where the widget will store the resulting text from the
     operation.  The parameter LBUFVAR will contain ‘LBUFFER’ and
     RBUFVAR will contain ‘RBUFFER’.  Neither of these two options may
     be used with ‘-S’ or ‘-R’.

     ‘narrow-to-region-invisible’ is a simple widget which calls
     ‘narrow-to-region’ with arguments which replace any text outside
     the region with ‘...’.  It does not take any arguments.

     The display is restored (and the widget returns) upon any zle
     command which would usually cause the line to be accepted or
     aborted.  Hence an additional such command is required to accept or
     abort the current line.

     The return status of both widgets is zero if the line was accepted,
     else non-zero.

     Here is a trivial example of a widget using this feature.

           local state
           narrow-to-region -p $'Editing restricted region\n' \
             -P '' -S state
           zle recursive-edit
           narrow-to-region -R state

‘predict-on’

     This set of functions implements predictive typing using history
     search.  After ‘predict-on’, typing characters causes the editor to
     look backward in the history for the first line beginning with what
     you have typed so far.  After ‘predict-off’, editing returns to
     normal for the line found.  In fact, you often don’t even need to
     use ‘predict-off’, because if the line doesn’t match something in
     the history, adding a key performs standard completion, and then
     inserts itself if no completions were found.  However, editing in
     the middle of a line is liable to confuse prediction; see the
     ‘toggle’ style below.

     With the function based completion system (which is needed for
     this), you should be able to type ‘TAB’ at almost any point to
     advance the cursor to the next >>‘<<‘interesting’’ character
     position (usually the end of the current word, but sometimes
     somewhere in the middle of the word).  And of course as soon as the
     entire line is what you want, you can accept with return, without
     needing to move the cursor to the end first.

     The first time ‘predict-on’ is used, it creates several additional
     widget functions:

     ‘delete-backward-and-predict’

          Replaces the ‘backward-delete-char’ widget.  You do not need
          to bind this yourself.

     ‘insert-and-predict’

          Implements predictive typing by replacing the ‘self-insert’
          widget.  You do not need to bind this yourself.

     ‘predict-off’

          Turns off predictive typing.

     Although you ‘autoload’ only the ‘predict-on’ function, it is
     necessary to create a keybinding for ‘predict-off’ as well.

           zle -N predict-on
           zle -N predict-off
           bindkey '^X^Z' predict-on
           bindkey '^Z' predict-off

‘read-from-minibuffer’

     This is most useful when called as a function from inside a widget,
     but will work correctly as a widget in its own right.  It prompts
     for a value below the current command line; a value may be input
     using all of the standard zle operations (and not merely the
     restricted set available when executing, for example,
     ‘execute-named-cmd’).  The value is then returned to the calling
     function in the parameter ‘$REPLY’ and the editing buffer restored
     to its previous state.  If the read was aborted by a keyboard break
     (typically ‘^G’), the function returns status 1 and ‘$REPLY’ is not
     set.

     If one argument is supplied to the function it is taken as a
     prompt, otherwise ‘?’ is used.  If two arguments are supplied, they
     are the prompt and the initial value of ‘$LBUFFER’, and if a third
     argument is given it is the initial value of ‘$RBUFFER’.  This
     provides a default value and starting cursor placement.  Upon
     return the entire buffer is the value of ‘$REPLY’.

     One option is available: ‘-k’ NUM specifies that NUM characters are
     to be read instead of a whole line.  The line editor is not invoked
     recursively in this case, so depending on the terminal settings the
     input may not be visible, and only the input keys are placed in
     ‘$REPLY’, not the entire buffer.  Note that unlike the ‘read’
     builtin NUM must be given; there is no default.

     The name is a slight misnomer, as in fact the shell’s own
     minibuffer is not used.  Hence it is still possible to call
     ‘executed-named-cmd’ and similar functions while reading a value.

‘replace-argument’, ‘replace-argument-edit’

     The function ‘replace-argument’ can be used to replace a command
     line argument in the current command line or, if the current
     command line is empty, in the last command line executed (the new
     command line is not executed).  Arguments are as delimited by
     standard shell syntax,

     If a numeric argument is given, that specifies the argument to be
     replaced.  0 means the command name, as in history expansion.  A
     negative numeric argument counts backward from the last word.

     If no numeric argument is given, the current argument is replaced;
     this is the last argument if the previous history line is being
     used.

     The function prompts for a replacement argument.

     If the widget contains the string ‘edit’, for example is defined as

           zle -N replace-argument-edit replace-argument

     then the function presents the current value of the argument for
     editing, otherwise the editing buffer for the replacement is
     initially empty.

‘replace-string’, ‘replace-pattern’

‘replace-string-again’, ‘replace-pattern-again’

     The function ‘replace-string’ implements three widgets.  If defined
     under the same name as the function, it prompts for two strings;
     the first (source) string will be replaced by the second everywhere
     it occurs in the line editing buffer.

     If the widget name contains the word ‘pattern’, for example by
     defining the widget using the command ‘zle -N replace-pattern
     replace-string’, then the matching is performed using zsh patterns.
     All zsh extended globbing patterns can be used in the source
     string; note that unlike filename generation the pattern does not
     need to match an entire word, nor do glob qualifiers have any
     effect.  In addition, the replacement string can contain parameter
     or command substitutions.  Furthermore, a ‘&’ in the replacement
     string will be replaced with the matched source string, and a
     backquoted digit ‘\’N will be replaced by the Nth parenthesised
     expression matched.  The form ‘\{’N‘}’ may be used to protect the
     digit from following digits.

     If the widget instead contains the word ‘regex’ (or ‘regexp’), then
     the matching is performed using regular expressions, respecting the
     setting of the option ‘RE_MATCH_PCRE’ (see the description of the
     function ‘regexp-replace’ below).  The special replacement
     facilities described above for pattern matching are available.

     By default the previous source or replacement string will not be
     offered for editing.  However, this feature can be activated by
     setting the style ‘edit-previous’ in the context ‘:zle:’WIDGET (for
     example, ‘:zle:replace-string’) to ‘true’.  In addition, a positive
     numeric argument forces the previous values to be offered, a
     negative or zero argument forces them not to be.

     The function ‘replace-string-again’ can be used to repeat the
     previous replacement; no prompting is done.  As with
     ‘replace-string’, if the name of the widget contains the word
     ‘pattern’ or ‘regex’, pattern or regular expression matching is
     performed, else a literal string replacement.  Note that the
     previous source and replacement text are the same whether pattern,
     regular expression or string matching is used.

     In addition, ‘replace-string’ shows the previous replacement above
     the prompt, so long as there was one during the current session; if
     the source string is empty, that replacement will be repeated
     without the widget prompting for a replacement string.

     For example, starting from the line:

           print This line contains fan and fond

     and invoking ‘replace-pattern’ with the source string ‘f(?)n’ and
     the replacement string ‘c\1r’ produces the not very useful line:

           print This line contains car and cord

     The range of the replacement string can be limited by using the
     ‘narrow-to-region-invisible’ widget.  One limitation of the current
     version is that ‘undo’ will cycle through changes to the
     replacement and source strings before undoing the replacement
     itself.

‘send-invisible’

     This is similar to read-from-minibuffer in that it may be called as
     a function from a widget or as a widget of its own, and
     interactively reads input from the keyboard.  However, the input
     being typed is concealed and a string of asterisks (‘*’) is shown
     instead.  The value is saved in the parameter ‘$INVISIBLE’ to which
     a reference is inserted into the editing buffer at the restored
     cursor position.  If the read was aborted by a keyboard break
     (typically ‘^G’) or another escape from editing such as
     ‘push-line’, ‘$INVISIBLE’ is set to empty and the original buffer
     is restored unchanged.

     If one argument is supplied to the function it is taken as a
     prompt, otherwise ‘Non-echoed text:’ is used (as in emacs).  If a
     second and third argument are supplied they are used to begin and
     end the reference to ‘$INVISIBLE’ that is inserted into the buffer.
     The default is to open with ‘${’, then ‘INVISIBLE’, and close with
     ‘}’, but many other effects are possible.

‘smart-insert-last-word’

     This function may replace the ‘insert-last-word’ widget, like so:

           zle -N insert-last-word smart-insert-last-word

     With a numeric argument, or when passed command line arguments in a
     call from another widget, it behaves like ‘insert-last-word’,
     except that words in comments are ignored when
     ‘INTERACTIVE_COMMENTS’ is set.

     Otherwise, the rightmost ‘‘interesting’’ word from the previous
     command is found and inserted. The default definition of
     ‘‘interesting’’ is that the word contains at least one alphabetic
     character, slash, or backslash. This definition may be overridden
     by use of the ‘‘match‘’ style.  The context used to look up the
     style is the widget name, so usually the context is
     ‘:insert-last-word’.  However, you can bind this function to
     different widgets to use different patterns:

           zle -N insert-last-assignment smart-insert-last-word
           zstyle :insert-last-assignment match '[[:alpha:]][][[:alnum:]]#=*'
           bindkey '\e=' insert-last-assignment

     If no interesting word is found and the ‘auto-previous’ style is
     set to a true value, the search continues upward through the
     history.  When ‘auto-previous’ is unset or false (the default), the
     widget must be invoked repeatedly in order to search earlier
     history lines.

‘transpose-lines’

     Only useful with a multi-line editing buffer; the lines here are
     lines within the current on-screen buffer, not history lines.  The
     effect is similar to the function of the same name in Emacs.

     Transpose the current line with the previous line and move the
     cursor to the start of the next line.  Repeating this (which can be
     done by providing a positive numeric argument) has the effect of
     moving the line above the cursor down by a number of lines.

     With a negative numeric argument, requires two lines above the
     cursor.  These two lines are transposed and the cursor moved to the
     start of the previous line.  Using a numeric argument less than -1
     has the effect of moving the line above the cursor up by minus that
     number of lines.

‘url-quote-magic’

     This widget replaces the built-in ‘self-insert’ to make it easier
     to type URLs as command line arguments.  As you type, the input
     character is analyzed and, if it may need quoting, the current word
     is checked for a URI scheme.  If one is found and the current word
     is not already in quotes, a backslash is inserted before the input
     character.

     Styles to control quoting behavior:

     ‘url-metas’

          This style is looked up in the context
          ‘:url-quote-magic:’SCHEME (where SCHEME is that of the current
          URL, e.g.  “‘ftp’”).  The value is a string listing the
          characters to be treated as globbing metacharacters when
          appearing in a URL using that scheme.  The default is to quote
          all zsh extended globbing characters, excluding ‘‘<’’ and
          ‘‘>’’ but including braces (as in brace expansion).  See also
          ‘url-seps’.

     ‘url-seps’

          Like ‘url-metas’, but lists characters that should be
          considered command separators, redirections, history
          references, etc.  The default is to quote the standard set of
          shell separators, excluding those that overlap with the
          extended globbing characters, but including ‘‘<’’ and ‘‘>’’
          and the first character of ‘$histchars’.

     ‘url-globbers’

          This style is looked up in the context ‘:url-quote-magic’.
          The values form a list of command names that are expected to
          do their own globbing on the URL string.  This implies that
          they are aliased to use the ‘noglob’ modifier.  When the first
          word on the line matches one of the values ‘and’ the URL
          refers to a local file (see ‘url-local-schema’), only the
          ‘url-seps’ characters are quoted; the ‘url-metas’ are left
          alone, allowing them to affect command-line parsing,
          completion, etc.  The default values are a literal ‘noglob’
          plus (when the ‘zsh/parameter’ module is available) any
          commands aliased to the helper function ‘urlglobber’ or its
          alias ‘globurl’.

     ‘url-local-schema’

          This style is always looked up in the context ‘:urlglobber’,
          even though it is used by both url-quote-magic and urlglobber.
          The values form a list of URI schema that should be treated as
          referring to local files by their real local path names, as
          opposed to files which are specified relative to a
          web-server-defined document root.  The defaults are “‘ftp’”
          and “‘file’”.

     ‘url-other-schema’

          Like ‘url-local-schema’, but lists all other URI schema upon
          which ‘urlglobber’ and ‘url-quote-magic’ should act.  If the
          URI on the command line does not have a scheme appearing
          either in this list or in ‘url-local-schema’, it is not
          magically quoted.  The default values are “‘http’”, “‘https’”,
          and “‘ftp’”.  When a scheme appears both here and in
          ‘url-local-schema’, it is quoted differently depending on
          whether the command name appears in ‘url-globbers’.

     Loading ‘url-quote-magic’ also defines a helper function
     ‘urlglobber’ and aliases ‘globurl’ to ‘noglob urlglobber’.  This
     function takes a local URL apart, attempts to pattern-match the
     local file portion of the URL path, and then puts the results back
     into URL format again.

‘vi-pipe’

     This function reads a movement command from the keyboard and then
     prompts for an external command.  The part of the buffer covered by
     the movement is piped to the external command and then replaced by
     the command’s output.  If the movement command is bound to vi-pipe,
     the current line is used.

     The function serves as an example for reading a vi movement command
     from within a user-defined widget.

‘which-command’

     This function is a drop-in replacement for the builtin widget
     ‘which-command’.  It has enhanced behaviour, in that it correctly
     detects whether or not the command word needs to be expanded as an
     alias; if so, it continues tracing the command word from the
     expanded alias until it reaches the command that will be executed.

     The style ‘whence’ is available in the context ‘:zle:$WIDGET’; this
     may be set to an array to give the command and options that will be
     used to investigate the command word found.  The default is ‘whence
     -c’.

‘zcalc-auto-insert’

     This function is useful together with the ‘zcalc’ function
     described in *note Mathematical Functions: 140.  It should be bound
     to a key representing a binary operator such as ‘+’, ‘-’, ‘*’ or
     ‘/’.  When running in zcalc, if the key occurs at the start of the
     line or immediately following an open parenthesis, the text ‘"ans
     "’ is inserted before the representation of the key itself.  This
     allows easy use of the answer from the previous calculation in the
     current line.  The text to be inserted before the symbol typed can
     be modified by setting the variable ‘ZCALC_AUTO_INSERT_PREFIX’.

     Hence, for example, typing ‘+12’ followed by return adds 12 to the
     previous result.

     If zcalc is in RPN mode (‘-r’ option) the effect of this binding is
     automatically suppressed as operators alone on a line are
     meaningful.

     When not in zcalc, the key simply inserts the symbol itself.


File: zsh.info,  Node: Utility Functions<2>,  Next: Styles<2>,  Prev: Widgets,  Up: ZLE Functions

25.7.2 Utility Functions
------------------------

These functions are useful in constructing widgets.  They should be
loaded with ‘autoload -U’ FUNCTION and called as indicated from
user-defined widgets.

‘split-shell-arguments’

     This function splits the line currently being edited into shell
     arguments and whitespace.  The result is stored in the array
     ‘reply’.  The array contains all the parts of the line in order,
     starting with any whitespace before the first argument, and
     finishing with any whitespace after the last argument.  Hence (so
     long as the option ‘KSH_ARRAYS’ is not set) whitespace is given by
     odd indices in the array and arguments by even indices.  Note that
     no stripping of quotes is done; joining together all the elements
     of ‘reply’ in order is guaranteed to produce the original line.

     The parameter ‘REPLY’ is set to the index of the word in ‘reply’
     which contains the character after the cursor, where the first
     element has index 1.  The parameter ‘REPLY2’ is set to the index of
     the character under the cursor in that word, where the first
     character has index 1.

     Hence ‘reply’, ‘REPLY’ and ‘REPLY2’ should all be made local to the
     enclosing function.

     See the function ‘modify-current-argument’, described below, for an
     example of how to call this function.

‘modify-current-argument’ [ EXPR-USING-‘$ARG’ | FUNC ]

     This function provides a simple method of allowing user-defined
     widgets to modify the command line argument under the cursor (or
     immediately to the left of the cursor if the cursor is between
     arguments).

     The argument can be an expression which when evaluated operates on
     the shell parameter ‘ARG’, which will have been set to the command
     line argument under the cursor.  The expression should be suitably
     quoted to prevent it being evaluated too early.

     Alternatively, if the argument does not contain the string ‘ARG’,
     it is assumed to be a shell function, to which the current command
     line argument is passed as the only argument.  The function should
     set the variable ‘REPLY’ to the new value for the command line
     argument.  If the function returns non-zero status, so does the
     calling function.

     For example, a user-defined widget containing the following code
     converts the characters in the argument under the cursor into all
     upper case:

           modify-current-argument '${(U)ARG}'

     The following strips any quoting from the current word (whether
     backslashes or one of the styles of quotes), and replaces it with
     single quoting throughout:

           modify-current-argument '${(qq)${(Q)ARG}}'

     The following performs directory expansion on the command line
     argument and replaces it by the absolute path:

           expand-dir() {
             REPLY=${~1}
             REPLY=${REPLY:a}
           }
           modify-current-argument expand-dir

     In practice the function ‘expand-dir’ would probably not be defined
     within the widget where ‘modify-current-argument’ is called.


File: zsh.info,  Node: Styles<2>,  Prev: Utility Functions<2>,  Up: ZLE Functions

25.7.3 Styles
-------------

The behavior of several of the above widgets can be controlled by the
use of the ‘zstyle’ mechanism.  In particular, widgets that interact
with the completion system pass along their context to any completions
that they invoke.

‘break-keys’

     This style is used by the ‘incremental-complete-word’ widget.  Its
     value should be a pattern, and all keys matching this pattern will
     cause the widget to stop incremental completion without the key
     having any further effect.  Like all styles used directly by
     ‘incremental-complete-word’, this style is looked up using the
     context ‘:incremental’.

‘completer’

     The ‘incremental-complete-word’ and ‘insert-and-predict’ widgets
     set up their top-level context name before calling completion.
     This allows one to define different sets of completer functions for
     normal completion and for these widgets.  For example, to use
     completion, approximation and correction for normal completion,
     completion and correction for incremental completion and only
     completion for prediction one could use:

           zstyle ':completion:*' completer \
                   _complete _correct _approximate
           zstyle ':completion:incremental:*' completer \
                   _complete _correct
           zstyle ':completion:predict:*' completer \
                   _complete

     It is a good idea to restrict the completers used in prediction,
     because they may be automatically invoked as you type.  The ‘_list’
     and ‘_menu’ completers should never be used with prediction.  The
     ‘_approximate’, ‘_correct’, ‘_expand’, and ‘_match’ completers may
     be used, but be aware that they may change characters anywhere in
     the word behind the cursor, so you need to watch carefully that the
     result is what you intended.

‘cursor’

     The ‘insert-and-predict’ widget uses this style, in the context
     ‘:predict’, to decide where to place the cursor after completion
     has been tried.  Values are:

     ‘complete’

          The cursor is left where it was when completion finished, but
          only if it is after a character equal to the one just inserted
          by the user.  If it is after another character, this value is
          the same as ‘key’.

     ‘key’

          The cursor is left after the Nth occurrence of the character
          just inserted, where N is the number of times that character
          appeared in the word before completion was attempted.  In
          short, this has the effect of leaving the cursor after the
          character just typed even if the completion code found out
          that no other characters need to be inserted at that position.

     Any other value for this style unconditionally leaves the cursor at
     the position where the completion code left it.

‘list’

     When using the ‘incremental-complete-word’ widget, this style says
     if the matches should be listed on every key press (if they fit on
     the screen).  Use the context prefix ‘:completion:incremental’.

     The ‘insert-and-predict’ widget uses this style to decide if the
     completion should be shown even if there is only one possible
     completion.  This is done if the value of this style is the string
     ‘always’.  In this case the context is ‘:predict’ (‘not’
     ‘:completion:predict’).

‘match’

     This style is used by ‘smart-insert-last-word’ to provide a pattern
     (using full ‘EXTENDED_GLOB’ syntax) that matches an interesting
     word.  The context is the name of the widget to which
     ‘smart-insert-last-word’ is bound (see above).  The default
     behavior of ‘smart-insert-last-word’ is equivalent to:

           zstyle :insert-last-word match '*[[:alpha:]/\\]*'

     However, you might want to include words that contain spaces:

           zstyle :insert-last-word match '*[[:alpha:][:space:]/\\]*'

     Or include numbers as long as the word is at least two characters
     long:

           zstyle :insert-last-word match '*([[:digit:]]?|[[:alpha:]/\\])*'

     The above example causes redirections like “2>” to be included.

‘prompt’

     The ‘incremental-complete-word’ widget shows the value of this
     style in the status line during incremental completion.  The string
     value may contain any of the following substrings in the manner of
     the ‘PS1’ and other prompt parameters:

     ‘%c’

          Replaced by the name of the completer function that generated
          the matches (without the leading underscore).

     ‘%l’

          When the ‘list’ style is set, replaced by ‘...’ if the list of
          matches is too long to fit on the screen and with an empty
          string otherwise.  If the ‘list’ style is ‘false’ or not set,
          ‘%l’ is always removed.

     ‘%n’

          Replaced by the number of matches generated.

     ‘%s’

          Replaced by ‘-no match-’, ‘-no prefix-’, or an empty string if
          there is no completion matching the word on the line, if the
          matches have no common prefix different from the word on the
          line, or if there is such a common prefix, respectively.

     ‘%u’

          Replaced by the unambiguous part of all matches, if there is
          any, and if it is different from the word on the line.

     Like ‘break-keys’, this uses the ‘:incremental’ context.

‘stop-keys’

     This style is used by the ‘incremental-complete-word’ widget.  Its
     value is treated similarly to the one for the ‘break-keys’ style
     (and uses the same context: ‘:incremental’).  However, in this case
     all keys matching the pattern given as its value will stop
     incremental completion and will then execute their usual function.

‘toggle’

     This boolean style is used by ‘predict-on’ and its related widgets
     in the context ‘:predict’.  If set to one of the standard ‘true’
     values, predictive typing is automatically toggled off in
     situations where it is unlikely to be useful, such as when editing
     a multi-line buffer or after moving into the middle of a line and
     then deleting a character.  The default is to leave prediction
     turned on until an explicit call to ‘predict-off’.

‘verbose’

     This boolean style is used by ‘predict-on’ and its related widgets
     in the context ‘:predict’.  If set to one of the standard ‘true’
     values, these widgets display a message below the prompt when the
     predictive state is toggled.  This is most useful in combination
     with the ‘toggle’ style.  The default does not display these
     messages.

‘widget’

     This style is similar to the ‘command’ style: For widget functions
     that use ‘zle’ to call other widgets, this style can sometimes be
     used to override the widget which is called.  The context for this
     style is the name of the calling widget (‘not’ the name of the
     calling function, because one function may be bound to multiple
     widget names).

           zstyle :copy-earlier-word widget smart-insert-last-word

     Check the documentation for the calling widget or function to
     determine whether the ‘widget’ style is used.


File: zsh.info,  Node: Exception Handling,  Next: MIME Functions,  Prev: ZLE Functions,  Up: User Contributions

25.8 Exception Handling
=======================

Two functions are provided to enable zsh to provide exception handling
in a form that should be familiar from other languages.

‘throw’ EXCEPTION

     The function ‘throw’ throws the named EXCEPTION.  The name is an
     arbitrary string and is only used by the ‘throw’ and ‘catch’
     functions.  An exception is for the most part treated the same as a
     shell error, i.e.  an unhandled exception will cause the shell to
     abort all processing in a function or script and to return to the
     top level in an interactive shell.

‘catch’ EXCEPTION-PATTERN

     The function ‘catch’ returns status zero if an exception was thrown
     and the pattern EXCEPTION-PATTERN matches its name.  Otherwise it
     returns status 1.  EXCEPTION-PATTERN is a standard shell pattern,
     respecting the current setting of the ‘EXTENDED_GLOB’ option.  An
     alias ‘catch’ is also defined to prevent the argument to the
     function from matching filenames, so patterns may be used unquoted.
     Note that as exceptions are not fundamentally different from other
     shell errors it is possible to catch shell errors by using an empty
     string as the exception name.  The shell variable ‘CAUGHT’ is set
     by ‘catch’ to the name of the exception caught.  It is possible to
     rethrow an exception by calling the ‘throw’ function again once an
     exception has been caught.  ..  index:: single: catch; Function

The functions are designed to be used together with the ‘always’
construct described in *note Complex Commands: 1c5.  This is important
as only this construct provides the required support for exceptions.  A
typical example is as follows.

      {
        # "try" block
        # ... nested code here calls "throw MyExcept"
      } always {
        # "always" block
        if catch MyExcept; then
          print "Caught exception MyExcept"
        elif catch ''; then
          print "Caught a shell error.  Propagating..."
          throw ''
        fi
        # Other exceptions are not handled but may be caught further
        # up the call stack.
      }

If all exceptions should be caught, the following idiom might be
preferable.

      {
        # ... nested code here throws an exception
      } always {
        if catch *; then
          case $CAUGHT in
            (MyExcept)
            print "Caught my own exception"
            ;;
            (*)
            print "Caught some other exception"
            ;;
          esac
        fi
      }

In common with exception handling in other languages, the exception may
be thrown by code deeply nested inside the ‘try’ block.  However, note
that it must be thrown inside the current shell, not in a subshell
forked for a pipeline, parenthesised current-shell construct, or some
form of command or process substitution.

The system internally uses the shell variable ‘EXCEPTION’ to record the
name of the exception between throwing and catching.  One drawback of
this scheme is that if the exception is not handled the variable
‘EXCEPTION’ remains set and may be incorrectly recognised as the name of
an exception if a shell error subsequently occurs.  Adding ‘unset
EXCEPTION’ at the start of the outermost layer of any code that uses
exception handling will eliminate this problem.


File: zsh.info,  Node: MIME Functions,  Next: Mathematical Functions,  Prev: Exception Handling,  Up: User Contributions

25.9 MIME Functions
===================

Three functions are available to provide handling of files recognised by
extension, for example to dispatch a file ‘text.ps’ when executed as a
command to an appropriate viewer.

‘zsh-mime-setup’ [ ‘-fv’ ] [ ‘-l’ [ SUFFIX … ] ]

‘zsh-mime-handler’ [ ‘-l’ ] COMMAND ARGUMENT …

     These two functions use the files ‘~/.mime.types’ and
     ‘/etc/mime.types’, which associate types and extensions, as well as
     ‘~/.mailcap’ and ‘/etc/mailcap’ files, which associate types and
     the programs that handle them.  These are provided on many systems
     with the Multimedia Internet Mail Extensions.

     To enable the system, the function ‘zsh-mime-setup’ should be
     autoloaded and run.  This allows files with extensions to be
     treated as executable; such files be completed by the function
     completion system.  The function ‘zsh-mime-handler’ should not need
     to be called by the user.

     The system works by setting up suffix aliases with ‘alias -s’.
     Suffix aliases already installed by the user will not be
     overwritten.

     For suffixes defined in lower case, upper case variants will also
     automatically be handled (e.g.  ‘PDF’ is automatically handled if
     handling for the suffix ‘pdf’ is defined), but not vice versa.

     Repeated calls to ‘zsh-mime-setup’ do not override the existing
     mapping between suffixes and executable files unless the option
     ‘-f’ is given.  Note, however, that this does not override existing
     suffix aliases assigned to handlers other than ‘zsh-mime-handler’.

     Calling ‘zsh-mime-setup’ with the option ‘-l’ lists the existing
     mappings without altering them.  Suffixes to list (which may
     contain pattern characters that should be quoted from immediate
     interpretation on the command line) may be given as additional
     arguments, otherwise all suffixes are listed.

     Calling ‘zsh-mime-setup’ with the option ‘-v’ causes verbose output
     to be shown during the setup operation.

     The system respects the ‘mailcap’ flags ‘needsterminal’ and
     ‘copiousoutput’; see ‘mailcap(4)’ or ‘mailcap(5)’ (the man page’s
     name varies across platforms).

     The functions use the following styles, which are defined with the
     ‘zstyle’ builtin command (*note The zsh/zutil Module: ca.).  They
     should be defined before ‘zsh-mime-setup’ is run.  The contexts
     used all start with ‘:mime:’, with additional components in some
     cases.  It is recommended that a trailing ‘*’ (suitably quoted) be
     appended to style patterns in case the system is extended in
     future.  Some examples are given below.

     For files that have multiple suffixes, e.g.  ‘.pdf.gz’, where the
     context includes the suffix it will be looked up starting with the
     longest possible suffix until a match for the style is found.  For
     example, if ‘.pdf.gz’ produces a match for the handler, that will
     be used; otherwise the handler for ‘.gz’ will be used.  Note that,
     owing to the way suffix aliases work, it is always required that
     there be a handler for the shortest possible suffix, so in this
     example ‘.pdf.gz’ can only be handled if ‘.gz’ is also handled
     (though not necessarily in the same way).  Alternatively, if no
     handling for ‘.gz’ on its own is needed, simply adding the command

           alias -s gz=zsh-mime-handler

     to the initialisation code is sufficient; ‘.gz’ will not be handled
     on its own, but may be in combination with other suffixes.

     ‘current-shell’

          If this boolean style is true, the mailcap handler for the
          context in question is run using the ‘eval’ builtin instead of
          by starting a new ‘sh’ process.  This is more efficient, but
          may not work in the occasional cases where the mailcap handler
          uses strict POSIX syntax.

     ‘disown’

          If this boolean style is true, mailcap handlers started in the
          background will be disowned, i.e.  not subject to job control
          within the parent shell.  Such handlers nearly always produce
          their own windows, so the only likely harmful side effect of
          setting the style is that it becomes harder to kill jobs from
          within the shell.

     ‘execute-as-is’

          This style gives a list of patterns to be matched against
          files passed for execution with a handler program.  If the
          file matches the pattern, the entire command line is executed
          in its current form, with no handler.  This is useful for
          files which might have suffixes but nonetheless be executable
          in their own right.  If the style is not set, the pattern
          ‘*(*) *(/)’ is used; hence executable files are executed
          directly and not passed to a handler, and the option ‘AUTO_CD’
          may be used to change to directories that happen to have MIME
          suffixes.

     ‘execute-never’

          This style is useful in combination with ‘execute-as-is’.  It
          is set to an array of patterns corresponding to full paths to
          files that should never be treated as executable, even if the
          file passed to the MIME handler matches ‘execute-as-is’.  This
          is useful for file systems that don’t handle execute
          permission or that contain executables from another operating
          system.  For example, if ‘/mnt/windows’ is a Windows mount,
          then

                zstyle ':mime:*' execute-never '/mnt/windows/*'

          will ensure that any files found in that area will be executed
          as MIME types even if they are executable.  As this example
          shows, the complete file name is matched against the pattern,
          regardless of how the file was passed to the handler.  The
          file is resolved to a full path using the ‘:P’ modifier
          described in *note Modifiers: 6b.; this means that symbolic
          links are resolved where possible, so that links into other
          file systems behave in the correct fashion.

     ‘file-path’

          Used if the style ‘find-file-in-path’ is true for the same
          context.  Set to an array of directories that are used for
          searching for the file to be handled; the default is the
          command path given by the special parameter ‘path’.  The shell
          option ‘PATH_DIRS’ is respected; if that is set, the
          appropriate path will be searched even if the name of the file
          to be handled as it appears on the command line contains a
          ‘/’.  The full context is ‘:mime:.’SUFFIX‘:’, as described for
          the style ‘handler’.

     ‘find-file-in-path’

          If set, allows files whose names do not contain absolute paths
          to be searched for in the command path or the path specified
          by the ‘file-path’ style.  If the file is not found in the
          path, it is looked for locally (whether or not the current
          directory is in the path); if it is not found locally, the
          handler will abort unless the ‘handle-nonexistent’ style is
          set.  Files found in the path are tested as described for the
          style ‘execute-as-is’.  The full context is
          ‘:mime:.’SUFFIX‘:’, as described for the style ‘handler’.

     ‘flags’

          Defines flags to go with a handler; the context is as for the
          ‘handler’ style, and the format is as for the flags in
          ‘mailcap’.

     ‘handle-nonexistent’

          By default, arguments that don’t correspond to files are not
          passed to the MIME handler in order to prevent it from
          intercepting commands found in the path that happen to have
          suffixes.  This style may be set to an array of extended glob
          patterns for arguments that will be passed to the handler even
          if they don’t exist.  If it is not explicitly set it defaults
          to ‘[[:alpha:]]#:/*’ which allows URLs to be passed to the
          MIME handler even though they don’t exist in that format in
          the file system.  The full context is ‘:mime:.’SUFFIX‘:’, as
          described for the style ‘handler’.

     ‘handler’

          Specifies a handler for a suffix; the suffix is given by the
          context as ‘:mime:.’SUFFIX‘:’, and the format of the handler
          is exactly that in ‘mailcap’.  Note in particular the ‘.’ and
          trailing colon to distinguish this use of the context.  This
          overrides any handler specified by the ‘mailcap’ files.  If
          the handler requires a terminal, the ‘flags’ style should be
          set to include the word ‘needsterminal’, or if the output is
          to be displayed through a pager (but not if the handler is
          itself a pager), it should include ‘copiousoutput’.

     ‘mailcap’

          A list of files in the format of ‘~/.mailcap’ and
          ‘/etc/mailcap’ to be read during setup, replacing the default
          list which consists of those two files.  The context is
          ‘:mime:’.  A ‘+’ in the list will be replaced by the default
          files.

     ‘mailcap-priorities’

          This style is used to resolve multiple mailcap entries for the
          same MIME type.  It consists of an array of the following
          elements, in descending order of priority; later entries will
          be used if earlier entries are unable to resolve the entries
          being compared.  If none of the tests resolve the entries, the
          first entry encountered is retained.

          ‘files’

               The order of files (entries in the ‘mailcap’ style) read.
               Earlier files are preferred.  (Note this does not resolve
               entries in the same file.)

          ‘priority’

               The priority flag from the mailcap entry.  The priority
               is an integer from 0 to 9 with the default value being 5.

          ‘flags’

               The test given by the ‘mailcap-prio-flags’ option is used
               to resolve entries.

          ‘place’

               Later entries are preferred; as the entries are strictly
               ordered, this test always succeeds.

          Note that as this style is handled during initialisation, the
          context is always ‘:mime:’, with no discrimination by suffix.

     ‘mailcap-prio-flags’

          This style is used when the keyword ‘flags’ is encountered in
          the list of tests specified by the ‘mailcap-priorities’ style.
          It should be set to a list of patterns, each of which is
          tested against the flags specified in the mailcap entry (in
          other words, the sets of assignments found with some entries
          in the mailcap file).  Earlier patterns in the list are
          preferred to later ones, and matched patterns are preferred to
          unmatched ones.

     ‘mime-types’

          A list of files in the format of ‘~/.mime.types’ and
          ‘/etc/mime.types’ to be read during setup, replacing the
          default list which consists of those two files.  The context
          is ‘:mime:’.  A ‘+’ in the list will be replaced by the
          default files.

     ‘never-background’

          If this boolean style is set, the handler for the given
          context is always run in the foreground, even if the flags
          provided in the mailcap entry suggest it need not be (for
          example, it doesn’t require a terminal).

     ‘pager’

          If set, will be used instead of ‘$PAGER’ or ‘more’ to handle
          suffixes where the ‘copiousoutput’ flag is set.  The context
          is as for ‘handler’, i.e.  ‘:mime:.’SUFFIX‘:’ for handling a
          file with the given SUFFIX.

     Examples:

           zstyle ':mime:*' mailcap ~/.mailcap /usr/local/etc/mailcap
           zstyle ':mime:.txt:' handler less %s
           zstyle ':mime:.txt:' flags needsterminal

     When ‘zsh-mime-setup’ is subsequently run, it will look for
     ‘mailcap’ entries in the two files given.  Files of suffix ‘.txt’
     will be handled by running ‘less’ FILE.TXT.  The flag
     ‘needsterminal’ is set to show that this program must run attached
     to a terminal.

     As there are several steps to dispatching a command, the following
     should be checked if attempting to execute a file by extension
     ‘.’EXT does not have the expected effect.

     The command ‘alias -s’ EXT should show ‘ps=zsh-mime-handler’.  If
     it shows something else, another suffix alias was already installed
     and was not overwritten.  If it shows nothing, no handler was
     installed: this is most likely because no handler was found in the
     ‘.mime.types’ and ‘mailcap’ combination for ‘.ext’ files.  In that
     case, appropriate handling should be added to ‘~/.mime.types’ and
     ‘mailcap’.

     If the extension is handled by ‘zsh-mime-handler’ but the file is
     not opened correctly, either the handler defined for the type is
     incorrect, or the flags associated with it are in appropriate.
     Running ‘zsh-mime-setup -l’ will show the handler and, if there are
     any, the flags.  A ‘%s’ in the handler is replaced by the file
     (suitably quoted if necessary).  Check that the handler program
     listed lists and can be run in the way shown.  Also check that the
     flags ‘needsterminal’ or ‘copiousoutput’ are set if the handler
     needs to be run under a terminal; the second flag is used if the
     output should be sent to a pager.  An example of a suitable
     ‘mailcap’ entry for such a program is:

           text/html; /usr/bin/lynx '%s'; needsterminal

     Running ‘zsh-mime-handler -l’ COMMAND LINE prints the command line
     that would be executed, simplified to remove the effect of any
     flags, and quoted so that the output can be run as a complete zsh
     command line.  This is used by the completion system to decide how
     to complete after a file handled by ‘zsh-mime-setup’.

‘pick-web-browser’

     This function is separate from the two MIME functions described
     above and can be assigned directly to a suffix:

           autoload -U pick-web-browser
           alias -s html=pick-web-browser

     It is provided as an intelligent front end to dispatch a web
     browser.  It may be run as either a function or a shell script.
     The status 255 is returned if no browser could be started.

     Various styles are available to customize the choice of browsers:

     ‘browser-style’

          The value of the style is an array giving preferences in
          decreasing order for the type of browser to use.  The values
          of elements may be

          ‘running’

               Use a GUI browser that is already running when an X
               Window display is available.  The browsers listed in the
               ‘x-browsers’ style are tried in order until one is found;
               if it is, the file will be displayed in that browser, so
               the user may need to check whether it has appeared.  If
               no running browser is found, one is not started.
               Browsers other than Firefox, Opera and Konqueror are
               assumed to understand the Mozilla syntax for opening a
               URL remotely.

          ‘x’

               Start a new GUI browser when an X Window display is
               available.  Search for the availability of one of the
               browsers listed in the ‘x-browsers’ style and start the
               first one that is found.  No check is made for an already
               running browser.

          ‘tty’

               Start a terminal-based browser.  Search for the
               availability of one of the browsers listed in the
               ‘tty-browsers’ style and start the first one that is
               found.

          If the style is not set the default ‘running x tty’ is used.

     ‘x-browsers’

          An array in decreasing order of preference of browsers to use
          when running under the X Window System.  The array consists of
          the command name under which to start the browser.  They are
          looked up in the context ‘:mime:’ (which may be extended in
          future, so appending ‘*’ is recommended).  For example,

                zstyle ':mime:*' x-browsers opera konqueror firefox

          specifies that ‘pick-web-browser’ should first look for a
          running instance of Opera, Konqueror or Firefox, in that
          order, and if it fails to find any should attempt to start
          Opera.  The default is ‘firefox mozilla netscape opera
          konqueror’.

     ‘tty-browsers’

          An array similar to ‘x-browsers’, except that it gives
          browsers to use when no X Window display is available.  The
          default is ‘elinks links lynx’.

     ‘command’

          If it is set this style is used to pick the command used to
          open a page for a browser.  The context is
          ‘:mime:browser:new:$browser:’ to start a new browser or
          ‘:mime:browser:running:$browser:’ to open a URL in a browser
          already running on the current X display, where ‘$browser’ is
          the value matched in the ‘x-browsers’ or ‘tty-browsers’ style.
          The escape sequence ‘%b’ in the style’s value will be replaced
          by the browser, while ‘%u’ will be replaced by the URL. If the
          style is not set, the default for all new instances is
          equivalent to ‘%b %u’ and the defaults for using running
          browsers are equivalent to the values ‘kfmclient openURL %u’
          for Konqueror, ‘firefox -new-tab %u’ for Firefox, ‘opera
          -newpage %u’ for Opera, and ‘%b -remote "openUrl(%u)"’ for all
          others.


File: zsh.info,  Node: Mathematical Functions,  Next: User Configuration Functions,  Prev: MIME Functions,  Up: User Contributions

25.10 Mathematical Functions
============================

‘zcalc’ [ ‘-erf’ ] [ EXPRESSION … ]

     A reasonably powerful calculator based on zsh’s arithmetic
     evaluation facility.  The syntax is similar to that of formulae in
     most programming languages; see *note Arithmetic Evaluation: 1c7.
     for details.

     Non-programmers should note that, as in many other programming
     languages, expressions involving only integers (whether constants
     without a ‘.’, variables containing such constants as strings, or
     variables declared to be integers) are by default evaluated using
     integer arithmetic, which is not how an ordinary desk calculator
     operates.  To force floating point operation, pass the option ‘-f’;
     see further notes below.

     If the file ‘~/.zcalcrc’ exists it will be sourced inside the
     function once it is set up and about to process the command line.
     This can be used, for example, to set shell options; ‘emulate -L
     zsh’ and ‘setopt extendedglob’ are in effect at this point.  Any
     failure to source the file if it exists is treated as fatal.  As
     with other initialisation files, the directory ‘$ZDOTDIR’ is used
     instead of ‘$HOME’ if it is set.

     The mathematical library ‘zsh/mathfunc’ will be loaded if it is
     available; see *note The zsh/mathfunc Module: 119.  The
     mathematical functions correspond to the raw system libraries, so
     trigonometric functions are evaluated using radians, and so on.

     Each line typed is evaluated as an expression.  The prompt shows a
     number, which corresponds to a positional parameter where the
     result of that calculation is stored.  For example, the result of
     the calculation on the line preceded by ‘4>’ is available as ‘$4’.
     The last value calculated is available as ‘ans’.  Full command line
     editing, including the history of previous calculations, is
     available; the history is saved in the file ‘$ZCALC_HISTFILE’.  If
     ‘$ZCALC_HISTFILE’ is unset, ‘$ZDOTDIR/.zcalc_history’ is used
     instead, which in turn falls backs to ‘$HOME/.zcalc_history’ if
     ‘$ZDOTDIR’ is unset.  To exit, enter a blank line or type ‘:q’ on
     its own (‘q’ is allowed for historical compatibility).

     A line ending with a single backslash is treated in the same
     fashion as it is in command line editing: the backslash is removed,
     the function prompts for more input (the prompt is preceded by
     ‘...’ to indicate this), and the lines are combined into one to get
     the final result.  In addition, if the input so far contains more
     open than close parentheses ‘zcalc’ will prompt for more input.

     If arguments are given to ‘zcalc’ on start up, they are used to
     prime the first few positional parameters.  A visual indication of
     this is given when the calculator starts.

     The constants ‘PI’ (3.14159…) and ‘E’ (2.71828…) are provided.
     Parameter assignment is possible, but note that all parameters will
     be put into the global namespace unless the ‘:local’ special
     command is used.  The function creates local variables whose names
     start with ‘_’, so users should avoid doing so.  The variables
     ‘ans’ (the last answer) and ‘stack’ (the stack in RPN mode) may be
     referred to directly; ‘stack’ is an array but elements of it are
     numeric.  Various other special variables are used locally with
     their standard meaning, for example ‘compcontext’, ‘match’,
     ‘mbegin’, ‘mend’, ‘psvar’.

     The output base can be initialised by passing the option ‘-#’BASE,
     for example ‘zcalc -#16’ (the ‘#’ may have to be quoted, depending
     on the globbing options set).

     If the option ‘-e’ is set, the function runs non-interactively: the
     arguments are treated as expressions to be evaluated as if entered
     interactively line by line.

     If the option ‘-f’ is set, all numbers are treated as floating
     point, hence for example the expression ‘3/4’ evaluates to 0.75
     rather than 0.  Options must appear in separate words.

     If the option ‘-r’ is set, RPN (Reverse Polish Notation) mode is
     entered.  This has various additional properties:

     Stack

          Evaluated values are maintained in a stack; this is contained
          in an array named ‘stack’ with the most recent value in
          ‘${stack[1]}’.

     Operators and functions

          If the line entered matches an operator (‘+’, ‘-’, ‘*’, ‘/’,
          ‘**’, ‘^’, ‘|’ or ‘&’) or a function supplied by the
          ‘zsh/mathfunc’ library, the bottom element or elements of the
          stack are popped to use as the argument or arguments.  The
          higher elements of stack (least recent) are used as earlier
          arguments.  The result is then pushed into ‘${stack[1]}’.

     Expressions

          Other expressions are evaluated normally, printed, and added
          to the stack as numeric values.  The syntax within expressions
          on a single line is normal shell arithmetic (not RPN).

     Stack listing

          If an integer follows the option ‘-r’ with no space, then on
          every evaluation that many elements of the stack, where
          available, are printed instead of just the most recent result.
          Hence, for example, ‘zcalc -r4’ shows ‘$stack[4]’ to
          ‘$stack[1]’ each time results are printed.

     Duplication: ‘=’

          The pseudo-operator ‘=’ causes the most recent element of the
          stack to be duplicated onto the stack.

     ‘pop’

          The pseudo-function ‘pop’ causes the most recent element of
          the stack to be popped.  A ‘>’ on its own has the same effect.

     ‘>’IDENT

          The expression ‘>’ followed (with no space) by a shell
          identifier causes the most recent element of the stack to be
          popped and assigned to the variable with that name.  The
          variable is local to the ‘zcalc’ function.

     ‘<’IDENT

          The expression ‘<’ followed (with no space) by a shell
          identifier causes the value of the variable with that name to
          be pushed onto the stack.  IDENT may be an integer, in which
          case the previous result with that number (as shown before the
          ‘>’ in the standard ‘zcalc’ prompt) is put on the stack.

     Exchange: ‘xy’

          The pseudo-function ‘xy’ causes the most recent two elements
          of the stack to be exchanged.  ‘<>’ has the same effect.

     The prompt is configurable via the parameter ‘ZCALCPROMPT’, which
     undergoes standard prompt expansion.  The index of the current
     entry is stored locally in the first element of the array ‘psvar’,
     which can be referred to in ‘ZCALCPROMPT’ as ‘%1v’.  The default
     prompt is ‘%1v>’ .

     The variable ‘ZCALC_ACTIVE’ is set within the function and can be
     tested by nested functions; it has the value ‘rpn’ if RPN mode is
     active, else 1.

     A few special commands are available; these are introduced by a
     colon.  For backward compatibility, the colon may be omitted for
     certain commands.  Completion is available if ‘compinit’ has been
     run.

     The output precision may be specified within zcalc by special
     commands familiar from many calculators.

     ‘:norm’

          The default output format.  It corresponds to the printf ‘%g’
          specification.  Typically this shows six decimal digits.

     ‘:sci’ DIGITS

          Scientific notation, corresponding to the printf ‘%g’ output
          format with the precision given by DIGITS.  This produces
          either fixed point or exponential notation depending on the
          value output.

     ‘:fix’ DIGITS

          Fixed point notation, corresponding to the printf ‘%f’ output
          format with the precision given by DIGITS.

     ‘:eng’ DIGITS

          Exponential notation, corresponding to the printf ‘%E’ output
          format with the precision given by DIGITS.

     ‘:raw’

          Raw output: this is the default form of the output from a math
          evaluation.  This may show more precision than the number
          actually possesses.

     Other special commands:

     ‘:!’LINE…

          Execute LINE… as a normal shell command line.  Note that it is
          executed in the context of the function, i.e.  with local
          variables.  Space is optional after ‘:!’.

     ‘:local’ ARG …

          Declare variables local to the function.  Other variables may
          be used, too, but they will be taken from or put into the
          global scope.

     ‘:function’ NAME [ BODY ]

          Define a mathematical function or (with no BODY) delete it.
          ‘:function’ may be abbreviated to ‘:func’ or simply ‘:f’.  The
          NAME may contain the same characters as a shell function name.
          The function is defined using ‘zmathfuncdef’, see below.

          Note that ‘zcalc’ takes care of all quoting.  Hence for
          example:

                :f cube $1 * $1 * $1

          defines a function to cube the sole argument.  Functions so
          defined, or indeed any functions defined directly or
          indirectly using ‘functions -M’, are available to execute by
          typing only the name on the line in RPN mode; this pops the
          appropriate number of arguments off the stack to pass to the
          function, i.e.  1 in the case of the example ‘cube’ function.
          If there are optional arguments only the mandatory arguments
          are supplied by this means.

     ‘[#’BASE‘]’

          This is not a special command, rather part of normal
          arithmetic syntax; however, when this form appears on a line
          by itself the default output radix is set to BASE.  Use, for
          example, ‘[#16]’ to display hexadecimal output preceded by an
          indication of the base, or ‘[##16]’ just to display the raw
          number in the given base.  Bases themselves are always
          specified in decimal.  ‘[#]’ restores the normal output
          format.  Note that setting an output base suppresses floating
          point output; use ‘[#]’ to return to normal operation.

     ‘$’VAR

          Print out the value of var literally; does not affect the
          calculation.  To use the value of var, omit the leading ‘$’.

     See the comments in the function for a few extra tips.

‘min(’ARG‘, ...)’

‘max(’ARG‘, ...)’

‘sum(’ARG‘, ...)’

‘zmathfunc’

     The function ‘zmathfunc’ defines the three mathematical functions
     ‘min’, ‘max’, and ‘sum’.  The functions ‘min’ and ‘max’ take one or
     more arguments.  The function ‘sum’ takes zero or more arguments.
     Arguments can be of different types (ints and floats).

     Not to be confused with the ‘zsh/mathfunc’ module, described in
     *note The zsh/mathfunc Module: 119.

‘zmathfuncdef’ [ MATHFUNC [ BODY ] ]

     A convenient front end to ‘functions -M’.

     With two arguments, define a mathematical function named MATHFUNC
     which can be used in any form of arithmetic evaluation.  BODY is a
     mathematical expression to implement the function.  It may contain
     references to position parameters ‘$1’, ‘$2’, … to refer to
     mandatory parameters and ‘${1:-’DEFVALUE‘}’ … to refer to optional
     parameters.  Note that the forms must be strictly adhered to for
     the function to calculate the correct number of arguments.  The
     implementation is held in a shell function named
     ‘zsh_math_func_’MATHFUNC; usually the user will not need to refer
     to the shell function directly.  Any existing function of the same
     name is silently replaced.

     With one argument, remove the mathematical function MATHFUNC as
     well as the shell function implementation.

     With no arguments, list all MATHFUNC functions in a form suitable
     for restoring the definition.  The functions have not necessarily
     been defined by ‘zmathfuncdef’.


File: zsh.info,  Node: User Configuration Functions,  Next: Other Functions<2>,  Prev: Mathematical Functions,  Up: User Contributions

25.11 User Configuration Functions
==================================

The ‘zsh/newuser’ module comes with a function to aid in configuring
shell options for new users.  If the module is installed, this function
can also be run by hand.  It is available even if the module’s default
behaviour, namely running the function for a new user logging in without
startup files, is inhibited.

‘zsh-newuser-install’ [ ‘-f’ ]

     The function presents the user with various options for customizing
     their initialization scripts.  Currently only ‘~/.zshrc’ is
     handled.  ‘$ZDOTDIR/.zshrc’ is used instead if the parameter
     ‘ZDOTDIR’ is set; this provides a way for the user to configure a
     file without altering an existing ‘.zshrc’.

     By default the function exits immediately if it finds any of the
     files ‘.zshenv’, ‘.zprofile’, ‘.zshrc’, or ‘.zlogin’ in the
     appropriate directory.  The option ‘-f’ is required in order to
     force the function to continue.  Note this may happen even if
     ‘.zshrc’ itself does not exist.

     As currently configured, the function will exit immediately if the
     user has root privileges; this behaviour cannot be overridden.

     Once activated, the function’s behaviour is supposed to be
     self-explanatory.  Menus are present allowing the user to alter the
     value of options and parameters.  Suggestions for improvements are
     always welcome.

     When the script exits, the user is given the opportunity to save
     the new file or not; changes are not irreversible until this point.
     However, the script is careful to restrict changes to the file only
     to a group marked by the lines ‘# Lines configured by
     zsh-newuser-install’ and ‘# End of lines configured by
     zsh-newuser-install’.  In addition, the old version of ‘.zshrc’ is
     saved to a file with the suffix ‘.zni’ appended.

     If the function edits an existing ‘.zshrc’, it is up to the user to
     ensure that the changes made will take effect.  For example, if
     control usually returns early from the existing ‘.zshrc’ the lines
     will not be executed; or a later initialization file may override
     options or parameters, and so on.  The function itself does not
     attempt to detect any such conflicts.


File: zsh.info,  Node: Other Functions<2>,  Prev: User Configuration Functions,  Up: User Contributions

25.12 Other Functions
=====================

There are a large number of helpful functions in the ‘Functions/Misc’
directory of the zsh distribution.  Most are very simple and do not
require documentation here, but a few are worthy of special mention.

* Menu:

* Descriptions::
* Styles: Styles<3>.


File: zsh.info,  Node: Descriptions,  Next: Styles<3>,  Up: Other Functions<2>

25.12.1 Descriptions
--------------------

‘colors’

     This function initializes several associative arrays to map color
     names to (and from) the ANSI standard eight-color terminal codes.
     These are used by the prompt theme system (see *note Prompt Themes:
     1e.).  You seldom should need to run ‘colors’ more than once.

     The eight base colors are: ‘black’, ‘red’, ‘green’, ‘yellow’,
     ‘blue’, ‘magenta’, ‘cyan’, and ‘white’.  Each of these has codes
     for foreground and background.  In addition there are seven
     intensity attributes: ‘bold’, ‘faint’, ‘italic’, ‘underline’,
     ‘blink’, ‘reverse’, and ‘conceal’.  Finally, there are seven codes
     used to negate attributes: ‘none’ (reset all attributes to the
     defaults), ‘normal’ (neither bold nor faint), ‘no-italic’,
     ‘no-underline’, ‘no-blink’, ‘no-reverse’, and ‘no-conceal’.

     Some terminals do not support all combinations of colors and
     intensities.  Prior to zsh ‘5.8.1’ the intensity ‘standout’ was
     provided.  It has been replaced by the more specific ‘italic’ and
     ‘reverse’ to match the specification, but some terminals may swap
     these or make one of them produce blinking text even if the ‘blink’
     code is not usable.

     The associative arrays are:

     ‘color’

     ‘colour’

          Map all the color names to their integer codes, and integer
          codes to the color names.  The eight base names map to the
          foreground color codes, as do names prefixed with ‘fg-’, such
          as ‘fg-red’.  Names prefixed with ‘bg-’, such as ‘bg-blue’,
          refer to the background codes.  The reverse mapping from code
          to color yields base name for foreground codes and the ‘bg-’
          form for backgrounds.

          Although it is a misnomer to call them ‘colors’, these arrays
          also map the other fourteen attributes from names to codes and
          codes to names.

     ‘fg’

     ‘fg_bold’

     ‘fg_no_bold’

          Map the eight basic color names to ANSI terminal escape
          sequences that set the corresponding foreground text
          properties.  The ‘fg’ sequences change the color without
          changing the eight intensity attributes.

     ‘bg’

     ‘bg_bold’

     ‘bg_no_bold’

          Map the eight basic color names to ANSI terminal escape
          sequences that set the corresponding background properties.
          The ‘bg’ sequences change the color without changing the eight
          intensity attributes.

     In addition, the scalar parameters ‘reset_color’ and ‘bold_color’
     are set to the ANSI terminal escapes that turn off all attributes
     and turn on bold intensity, respectively.

‘fned’ [ ‘-x’ NUM ] NAME

     Same as ‘zed -f’.  This function does not appear in the zsh
     distribution, but can be created by linking ‘zed’ to the name
     ‘fned’ in some directory in your ‘fpath’.

‘histed’ [ [ NAME ] SIZE ]

     Same as ‘zed -h’.  This function does not appear in the zsh
     distribution, but can be created by linking ‘zed’ to the name
     ‘histed’ in some directory in your ‘fpath’.

‘is-at-least’ NEEDED [ PRESENT ]

     Perform a greater-than-or-equal-to comparison of two strings having
     the format of a zsh version number; that is, a string of numbers
     and text with segments separated by dots or dashes.  If the PRESENT
     string is not provided, ‘$ZSH_VERSION’ is used.  Segments are
     paired left-to-right in the two strings with leading non-number
     parts ignored.  If one string has fewer segments than the other,
     the missing segments are considered zero.

     This is useful in startup files to set options and other state that
     are not available in all versions of zsh.

           is-at-least 3.1.6-15 && setopt NO_GLOBAL_RCS
           is-at-least 3.1.0 && setopt HIST_REDUCE_BLANKS
           is-at-least 2.6-17 || print "You can't use is-at-least here."

‘mkshadow’ [ ‘-s’ SUFFIX ] [ – ] COMMAND_NAME …

‘rmshadow’

     These functions are an interface to the ‘_shadow’ and ‘_unshadow’
     completion utilities to make them more easily accessible in other
     contexts.  Usage is exactly as for the completion utility:

           {
             mkshadow fname
             function fname {
               # Do your new thing
             }
             # Invoke callers of fname
           } always {
             rmshadow
           }

     Upon return, the value of ‘$REPLY’ is the suffix used to create a
     copy of the original COMMAND_NAME, so COMMAND_NAME‘@$REPLY’ invokes
     that original.

‘nslookup’ [ ARG … ]

     This wrapper function for the ‘nslookup’ command requires the
     ‘zsh/zpty’ module (see *note The zsh/zpty Module: cd.).  It behaves
     exactly like the standard ‘nslookup’ except that it provides
     customizable prompts (including a right-side prompt) and completion
     of nslookup commands, host names, etc.  (if you use the
     function-based completion system).  Completion styles may be set
     with the context prefix ‘:completion:nslookup’.

     See also the ‘pager’, ‘prompt’ and ‘rprompt’ styles below.

‘regexp-replace’ VAR REGEXP [ REPLACE ]

     Use regular expressions to perform a global search and replace
     operation on a variable.  POSIX extended regular expressions (ERE)
     are used, unless the option ‘RE_MATCH_PCRE’ has been set, in which
     case Perl-compatible regular expressions are used (this requires
     the shell to be linked against the ‘pcre’ library).

     VAR is the name of the variable containing the string to be
     matched.  The variable will be modified directly by the function.
     The variables ‘MATCH’, ‘MBEGIN’, ‘MEND’, ‘match’, ‘mbegin’, ‘mend’,
     as well as any variables starting with ‘_regexp_replace’ should be
     avoided as these are used by the regular expression code.

     REGEXP is the regular expression to match against the string.

     REPLACE is the replacement text.  This can contain parameter,
     command and arithmetic expressions which will be replaced: in
     particular, a reference to ‘$MATCH’ will be replaced by the text
     matched by the pattern.  If not given, matches are replaced with
     nothing.

     The return status is 0 if at least one match was performed, else 1.

     Note that if using POSIX EREs, the ‘^’ or word boundary operators
     (where available) may not work properly.

‘run-help’ CMD

     This function is designed to be invoked by the ‘run-help’ ZLE
     widget, in place of the default alias.  See *note Accessing On-Line
     Help: 19e. for setup instructions.

     In the discussion which follows, if CMD is a file system path, it
     is first reduced to its rightmost component (the file name).

     Help is first sought by looking for a file named CMD in the
     directory named by the ‘HELPDIR’ parameter.  If no file is found,
     an assistant function, alias, or command named
     ‘run-help-:var:`cmd’‘ is sought.  If found, the assistant is
     executed with the rest of the current command line (everything
     after the command name CMD) as its arguments.  When neither file
     nor assistant is found, the external command ‘man’ CMD is run.

     An example assistant for the “ssh” command:

           run-help-ssh() {
               emulate -LR zsh
               local -a args
               # Delete the "-l username" option
               zparseopts -D -E -a args l:
               # Delete other options, leaving: host command
               args=(${@:#-*})
               if [[ ${#args} -lt 2 ]]; then
                   man ssh
               else
                   run-help $args[2]
               fi
           }

     Several of these assistants are provided in the ‘Functions/Misc’
     directory.  These must be autoloaded, or placed as executable
     scripts in your search path, in order to be found and used by
     ‘run-help’.

     ‘run-help-btrfs’

     ‘run-help-git’

     ‘run-help-ip’

     ‘run-help-openssl’

     ‘run-help-p4’

     ‘run-help-sudo’

     ‘run-help-svk’

     ‘run-help-svn’

          Assistant functions for the ‘btrfs’, ‘git’, ‘ip’, ‘openssl’,
          ‘p4’, ‘sudo’, ‘svk’, and ‘svn’, commands.

‘tetris’

     Zsh was once accused of not being as complete as Emacs, because it
     lacked a Tetris game.  This function was written to refute this
     vicious slander.

     This function must be used as a ZLE widget:

           autoload -U tetris
           zle -N tetris
           bindkey KEYS tetris

     To start a game, execute the widget by typing the KEYS.  Whatever
     command line you were editing disappears temporarily, and your
     keymap is also temporarily replaced by the Tetris control keys.
     The previous editor state is restored when you quit the game (by
     pressing ‘q’) or when you lose.

     If you quit in the middle of a game, the next invocation of the
     ‘tetris’ widget will continue where you left off.  If you lost, it
     will start a new game.

‘tetriscurses’

     This is a port of the above to zcurses.  The input handling is
     improved a bit so that moving a block sideways doesn’t
     automatically advance a timestep, and the graphics use unicode
     block graphics.

     This version does not save the game state between invocations, and
     is not invoked as a widget, but rather as:

           autoload -U tetriscurses
           tetriscurses

‘zargs’ [ OPTION … ‘--’ ] [ INPUT … ] [ ‘--’ COMMAND [ ARG … ] ]

     This function has a similar purpose to GNU xargs.  Instead of
     reading lines of arguments from the standard input, it takes them
     from the command line.  This is useful because zsh, especially with
     recursive glob operators, often can construct a command line for a
     shell function that is longer than can be accepted by an external
     command.

     The OPTION list represents options of the ‘zargs’ command itself,
     which are the same as those of ‘xargs’.  The INPUT list is the
     collection of strings (often file names) that become the arguments
     of the ‘command’, analogous to the standard input of ‘xargs’.
     Finally, the ARG list consists of those arguments (usually options)
     that are passed to the COMMAND each time it runs.  The ARG list
     precedes the elements from the ‘input’ list in each run.  If no
     COMMAND is provided, then no ARG list may be provided, and in that
     event the default command is ‘print’ with arguments ‘-r --’.

     For example, to get a long ‘ls’ listing of all non-hidden plain
     files in the current directory or its subdirectories:

           autoload -U zargs
           zargs -- **/*(.) -- ls -ld --

     The first and third occurrences of ‘--’ are used to mark the end of
     options for ‘zargs’ and ‘ls’ respectively to guard against
     filenames starting with ‘-’, while the second is used to separate
     the list of files from the command to run (‘ls -ld --’).

     The first ‘--’ would also be needed if there was a chance the list
     might be empty as in:

           zargs -r -- ./*.back(#qN) -- rm -f

     In the event that the string ‘--’ is or may be an INPUT, the ‘-e’
     option may be used to change the end-of-inputs marker.  Note that
     this does ‘not’ change the end-of-options marker.  For example, to
     use ‘..’ as the marker:

           zargs -e.. -- **/*(.) .. ls -ld --

     This is a good choice in that example because no plain file can be
     named ‘..’, but the best end-marker depends on the circumstances.

     The options ‘-i’, ‘-I’, ‘-l’, ‘-L’, and ‘-n’ differ slightly from
     their usage in ‘xargs’.  There are no input lines for ‘zargs’ to
     count, so ‘-l’ and ‘-L’ count through the INPUT list, and ‘-n’
     counts the number of arguments passed to each execution of COMMAND,
     ‘including’ any ARG list.  Also, any time ‘-i’ or ‘-I’ is used,
     each INPUT is processed separately as if by ‘-L’ ‘1’.

     For details of the other ‘zargs’ options, see the ‘xargs(1)’ man
     page (but note the difference in function between ‘zargs’ and
     ‘xargs’) or run ‘zargs’ with the ‘--help’ option.

‘zed’ [ ‘-f’ [ ‘-x’ NUM ] ] NAME

‘zed’ [ ‘-h’ [ NAME ] SIZE ]

‘zed -b’

     This function uses the ZLE editor to edit a file or function.

     Only one NAME argument is allowed.  If the ‘-f’ option is given,
     the name is taken to be that of a function; if the function is
     marked for autoloading, ‘zed’ searches for it in the ‘fpath’ and
     loads it.  Note that functions edited this way are installed into
     the current shell, but ‘not’ written back to the autoload file.  In
     this case the ‘-x’ option specifies that leading tabs indenting the
     function according to syntax should be converted into the given
     number of spaces; ‘-x 2’ is consistent with the layout of functions
     distributed with the shell.

     Without ‘-f’, NAME is the path name of the file to edit, which need
     not exist; it is created on write, if necessary.  With ‘-h’, the
     file is presumed to contain history events.

     When no file name is provided for ‘-h’ the current shell history is
     edited in place.  The history is renumbered when zed exits
     successfully.

     When editing history, multi-line events must have a trailing
     backslash on every line before the last.

     While editing, the function sets the main keymap to ‘zed’ and the
     vi command keymap to ‘zed-vicmd’.  These will be copied from the
     existing ‘main’ and ‘vicmd’ keymaps if they do not exist the first
     time ‘zed’ is run.  They can be used to provide special key
     bindings used only in zed.

     If it creates the keymap, ‘zed’ rebinds the return key to insert a
     line break and ‘^X^W’ to accept the edit in the ‘zed’ keymap, and
     binds ‘ZZ’ to accept the edit in the ‘zed-vicmd’ keymap.

     The bindings alone can be installed by running ‘zed -b’.  This is
     suitable for putting into a startup file.  Note that, if rerun,
     this will overwrite the existing ‘zed’ and ‘zed-vicmd’ keymaps.

     Completion is available, and styles may be set with the context
     prefix ‘:completion:zed:’.

     A zle widget ‘zed-set-file-name’ is available.  This can be called
     by name from within zed using ‘\ex zed-set-file-name’ or can be
     bound to a key in either of the ‘zed’ or ‘zed-vicmd’ keymaps after
     ‘zed -b’ has been run.  When the widget is called, it prompts for a
     new name for the file being edited.  When zed exits the file will
     be written under that name and the original file will be left
     alone.  The widget has no effect when invoked from ‘zed -f’.  The
     completion context is changed to ‘:completion:zed-set-file-name:’.
     When editing the current history with ‘zed -h’, the history is
     first updated and then the file is written, but the global setting
     of ‘HISTFILE’ is not altered.

     While ‘zed-set-file-name’ is running, zed uses the keymap
     ‘zed-normal-keymap’, which is linked from the main keymap in effect
     at the time zed initialised its bindings.  (This is to make the
     return key operate normally.)  The result is that if the main
     keymap has been changed, the widget won’t notice.  This is not a
     concern for most users.

‘zcp’ [ ‘-finqQvwW’ ] SRCPAT DEST

‘zln’ [ ‘-finqQsvwW’ ] SRCPAT DEST

     Same as ‘zmv -C’ and ‘zmv -L’, respectively.  These functions do
     not appear in the zsh distribution, but can be created by linking
     ‘zmv’ to the names ‘zcp’ and ‘zln’ in some directory in your
     ‘fpath’.

‘zgetopt’ [ ‘-A’ ARRAY ] [ ‘-l’ SPEC ] [ ‘-n’ NAME ] [ ‘-o’ SPEC ] ‘--’
[ ARG … ]

     This is a wrapper around ‘zparseopts’ (from ‘zsh/zutil’) which
     provides an interface similar to the util-linux implementation of
     ‘getopt(1)’ (sometimes called GNU ‘getopt’).  It simplifies
     GNU-style argument parsing (including permutation) and can make it
     easier to write functions and scripts with complex APIs,
     particularly ones where the order of options is significant.

     The typical usage pattern is as follows:

           zgetopt -o abc: -l aaa,bbb,ccc: -- "$@" || return
           while (( $# )); do
             case $1 in
               -a|--aaa) ...; shift ;;        # handle -a
               -b|--bbb) ...; shift ;;        # handle -b
               -c|--ccc) ...; shift 2 ;;      # handle -c and arg
               --)       ...; shift; break ;; # end of options
             esac
           done
           # handle operands

     It can also be called as a stand-alone script from other shells
     using the more traditional print-and-eval pattern:

           args=$( zgetopt -n myscript -o abc: -l aaa,bbb,ccc: -- "$@" ) || return
           eval set -- "$args"
           while [ $# -ne 0 ]; do ...; done

     Options:

     ‘-A :var:`array’‘

          When called as a function, assign the parsed arguments to the
          named array ARRAY.  Defaults to ‘argv’, which overwrites the
          caller’s positional parameters.  Has no meaning when called as
          a script, in which case the parsed and quoted arguments are
          always printed to standard output.  An empty string forces the
          printing behaviour in either mode.

     ‘-l :var:`spec’‘

          Specify long options to recognise when parsing.  These should
          be given using just the option name (no dashes), suffixed by
          ‘:’ or ‘::’ if it takes a mandatory or optional argument
          respectively.  Multiple options can be defined either by
          separating them by commas or by supplying -l again.  Example:
          ‘-l foo,bar: -l baz’

     ‘-n :var:`name’‘

          Specify the name to use in the error message if argument
          parsing fails.  Defaults to the name of the nearest calling
          function or the base name of ‘$ZSH_ARGZERO’.  Note that errors
          related to the usage of ‘zgetopt’ itself are always reported
          as coming from ‘zgetopt’.

     ‘-o :var:`spec’‘

          Specify short options to recognise when parsing.  These should
          be given as a single string, in the same format used by the
          ‘getopts’ built-in or the ‘getopt(3)’ library function, again
          using ‘:’ or ‘::’ to indicate a mandatory or optional
          argument.  The spec may be prefixed with ‘+’ to indicate that
          option parsing should stop at the first non-option argument
          (equivalent to setting the environment variable
          ‘POSIXLY_CORRECT’).  Example: ‘-o ab:cd::’

     At least one of ‘-o’ or ‘-l’ must be given.  The function’s own
     options should be followed by zero or more arguments to parse.  It
     is critical that these be separated explicitly by ‘--’, as in the
     above examples, to ensure that the function can accurately
     distinguish the arguments it’s meant to parse from its own.

     Refer to the manual for util-linux’s ‘getopt(1)’ for more
     information about the way arguments are parsed and results are
     returned.  Note however that this function is not intended to be a
     complete re-implementation.  In particular: it omits all
     portability/compatibility features, it doesn’t support the
     ‘--alternative’ option, and it doesn’t support abbreviating long
     options.

‘zkbd’

     See *note Keyboard Definition: 1a3.

‘zmv’ [ ‘-finqQsvwW’ ] [ ‘-C’ | ‘-L’ | ‘-M’ | -{‘p|P’} PROGRAM ] [ ‘-o’
OPTSTRING ]

     SRCPAT DEST

     Move (usually, rename) files matching the pattern SRCPAT to
     corresponding files having names of the form given by DEST, where
     SRCPAT contains parentheses surrounding patterns which will be
     replaced in turn by ‘$1’, ‘$2’, … in DEST.  For example,

           zmv '(*).lis' '$1.txt'

     renames ‘foo.lis’ to ‘foo.txt’, ‘my.old.stuff.lis’ to
     ‘my.old.stuff.txt’, and so on.

     The pattern is always treated as an ‘EXTENDED_GLOB’ pattern.  Any
     file whose name is not changed by the substitution is simply
     ignored.  Any error (no files matched the SRCPAT, substitution
     resulted in an empty string, two substitutions gave the same
     result, the destination was an existing regular file and ‘-f’ was
     not given) causes the entire function to abort without doing
     anything.

     In addition to pattern replacement, the variable ‘$f’ can be
     referred to in the second (replacement) argument.  This makes it
     possible to use variable substitution to alter the argument; see
     examples below.

     Options:

     ‘-f’

          Force overwriting of destination files.  Not currently passed
          down to the ‘mv/cp/ln’ command due to vagaries of
          implementations (but you can use ‘-o-f’ to do that).

     ‘-i’

          Interactive: show each line to be executed and ask the user
          whether to execute it.  ‘Y’ or ‘y’ will execute it, anything
          else will skip it.  Note that you just need to type one
          character.

     ‘-n’

          No execution: print what would happen, but don’t do it.

     ‘-q’

          Turn bare glob qualifiers off: now assumed by default, so this
          has no effect.

     ‘-Q’

          Force bare glob qualifiers on.  Don’t turn this on unless you
          are actually using glob qualifiers in a pattern.

     ‘-s’

          Symbolic, passed down to ‘ln’; only works with ‘-L’.

     ‘-v’

          Verbose: print each command as it’s being executed.

     ‘-w’

          Pick out wildcard parts of the pattern, as described above,
          and implicitly add parentheses for referring to them.

     ‘-W’

          Just like ‘-w’, with the addition of turning wildcards in the
          replacement pattern into sequential ‘${1}’ ..  ‘${N}’
          references.

     ‘-C’

     ‘-L’

     ‘-M’

          Force ‘cp’, ‘ln’ or ‘mv’, respectively, regardless of the name
          of the function.

     ‘-p’ PROGRAM

          Call PROGRAM instead of ‘cp’, ‘ln’ or ‘mv’.  Whatever it does,
          it should at least understand the form

                PROGRAM -- OLDNAME NEWNAME

          where OLDNAME and NEWNAME are filenames generated by ‘zmv’.
          PROGRAM will be split into words, so might be e.g.  the name
          of an archive tool plus a copy or rename subcommand.

     ‘-P’ PROGRAM

          As ‘-p’ PROGRAM, except that PROGRAM does not accept a
          following ‘--’ to indicate the end of options.  In this case
          filenames must already be in a sane form for the program in
          question.

     ‘-o’ OPTSTRING

          The OPTSTRING is split into words and passed down verbatim to
          the ‘cp’, ‘ln’ or ‘mv’ command called to perform the work.  It
          should probably begin with a ‘-’.

     Further examples:

           zmv -v '(* *)' '${1// /_}'

     For any file in the current directory with at least one space in
     the name, replace every space by an underscore and display the
     commands executed.

           zmv -v '* *' '${f// /_}'

     This does exactly the same by referring to the file name stored in
     ‘$f’.

     For more complete examples and other implementation details, see
     the ‘zmv’ source file, usually located in one of the directories
     named in your ‘fpath’, or in ‘Functions/Misc/zmv’ in the zsh
     distribution.

‘zrecompile’

     See *note Recompiling Functions: 1a1.

‘zstyle+’ CONTEXT STYLE VALUE [ ‘+’ SUBCONTEXT STYLE VALUE … ]

     This makes defining styles a bit simpler by using a single ‘+’ as a
     special token that allows you to append a context name to the
     previously used context name.  Like this:

           zstyle+ ':foo:bar' STYLE1 VALUE1         +':baz'     STYLE2 VALUE2         +':frob'    STYLE3 VALUE3

     This defines STYLE1 with VALUE1 for the context ‘:foo:bar’ as
     usual, but it also defines STYLE2 with VALUE2 for the context
     ‘:foo:bar:baz’ and STYLE3 with VALUE3 for ‘:foo:bar:frob’.  Any
     SUBCONTEXT may be the empty string to re-use the first context
     unchanged.


File: zsh.info,  Node: Styles<3>,  Prev: Descriptions,  Up: Other Functions<2>

25.12.2 Styles
--------------

‘insert-tab’

     The ‘zed’ function ‘sets’ this style in context ‘:completion:zed:*’
     to turn off completion when ‘TAB’ is typed at the beginning of a
     line.  You may override this by setting your own value for this
     context and style.

‘pager’

     The ‘nslookup’ function looks up this style in the context
     ‘:nslookup’ to determine the program used to display output that
     does not fit on a single screen.

‘prompt’

‘rprompt’

     The ‘nslookup’ function looks up this style in the context
     ‘:nslookup’ to set the prompt and the right-side prompt,
     respectively.  The usual expansions for the ‘PS1’ and ‘RPS1’
     parameters may be used (see *note Expansion of Prompt Sequences:
     1ca.).


File: zsh.info,  Node: Index,  Prev: User Contributions,  Up: Top

Index
*****

[index]
* Menu:

* !; Variable:                           Parameters Set by the Shell.
                                                             (line   18)
* #; Variable:                           Parameters Set by the Shell.
                                                             (line   24)
* $0, setting; Command:                  Scripts and Functions.
                                                             (line  134)
* $0, using; Command:                    Shell Emulation.    (line  153)
* $; Variable:                           Parameters Set by the Shell.
                                                             (line   36)
* *; Variable:                           Parameters Set by the Shell.
                                                             (line   49)
* -; Function:                           Precommand Modifiers.
                                                             (line   11)
* -; Variable:                           Parameters Set by the Shell.
                                                             (line   44)
* -after, within [[; Function:           Completion Condition Codes.
                                                             (line   20)
* -array-value-, completion context; Keystroke: Autoloaded Files.
                                                             (line  109)
* -assign-parameter-, completion context; Keystroke: Autoloaded Files.
                                                             (line  113)
* -between, within [[; Function:         Completion Condition Codes.
                                                             (line   25)
* -brace-parameter-, completion context; Keystroke: Autoloaded Files.
                                                             (line  118)
* -command-, completion context; Keystroke: Autoloaded Files.
                                                             (line  122)
* -condition-, completion context; Keystroke: Autoloaded Files.
                                                             (line  126)
* -default-, completion context; Keystroke: Autoloaded Files.
                                                             (line  130)
* -equal-, completion context; Keystroke: Autoloaded Files.  (line  134)
* -first-, completion context; Keystroke: Autoloaded Files.  (line  138)
* –help; Command:                        Invocation<2>.      (line   77)
* -math-, completion context; Keystroke: Autoloaded Files.   (line  148)
* -parameter-, completion context; Keystroke: Autoloaded Files.
                                                             (line  152)
* -prefix, within [[; Function:          Completion Condition Codes.
                                                             (line   12)
* -redirect-, completion context; Keystroke: Autoloaded Files.
                                                             (line  156)
* -subscript-, completion context; Keystroke: Autoloaded Files.
                                                             (line  160)
* -suffix, within [[; Function:          Completion Condition Codes.
                                                             (line   16)
* -tilde-, completion context; Keystroke: Autoloaded Files.  (line  164)
* -value-, completion context; Keystroke: Autoloaded Files.  (line  169)
* –version; Command:                     Invocation<2>.      (line   77)
* .; Function:                           Shell Builtin Commands.
                                                             (line   42)
* .sh.command; Variable:                 Ksh Parameters.     (line   11)
* .sh.edchar; Variable:                  Ksh Parameters.     (line   15)
* .sh.edcol; Variable:                   Ksh Parameters.     (line   21)
* .sh.edmode; Variable:                  Ksh Parameters.     (line   25)
* .sh.edtext; Variable:                  Ksh Parameters.     (line   34)
* .sh.file; Variable:                    Ksh Parameters.     (line   38)
* .sh.fun; Variable:                     Ksh Parameters.     (line   42)
* .sh.level; Variable:                   Ksh Parameters.     (line   48)
* .sh.lineno; Variable:                  Ksh Parameters.     (line   54)
* .sh.match; Variable:                   Ksh Parameters.     (line   58)
* .sh.name; Variable:                    Ksh Parameters.     (line   68)
* .sh.subscript; Variable:               Ksh Parameters.     (line   75)
* .sh.subshell; Variable:                Ksh Parameters.     (line   81)
* .sh.value; Variable:                   Ksh Parameters.     (line   85)
* .sh.version; Variable:                 Ksh Parameters.     (line   91)
* .term.bg; Variable:                    Parameters Set by the Shell.
                                                             (line  286)
* .term.cursor; Variable:                Parameters Set by the Shell.
                                                             (line  280)
* .term.extensions, setting; Variable:   Terminal Extensions.
                                                             (line    6)
* .term.extensions; Variable:            Parameters Used by the Shell.
                                                             (line  539)
* .term.fg; Variable:                    Parameters Set by the Shell.
                                                             (line  293)
* .term.id; Variable:                    Parameters Set by the Shell.
                                                             (line  297)
* .term.mode; Variable:                  Parameters Set by the Shell.
                                                             (line  315)
* .term.querywait; Variable:             Parameters Used by the Shell.
                                                             (line  544)
* .term.version; Variable:               Parameters Set by the Shell.
                                                             (line  310)
* .zle.esc; Variable:                    The zsh/hlgroup Module.
                                                             (line   13)
* .zle.sgr; Variable:                    The zsh/hlgroup Module.
                                                             (line   20)
* .zwc files, creation; Command:         Shell Builtin Commands.
                                                             (line 2923)
* 0; Variable:                           Parameters Set by the Shell.
                                                             (line   73)
* ;; Function:                           Shell Builtin Commands.
                                                             (line   65)
* ?; Variable:                           Parameters Set by the Shell.
                                                             (line   69)
* @; Variable:                           Parameters Set by the Shell.
                                                             (line   65)
* [[; Function:                          Complex Commands.   (line  223)
* _; Variable:                           Parameters Set by the Shell.
                                                             (line   91)
* _absolute_command_paths; Function:     Utility Functions.  (line   14)
* _all_labels; Function:                 Utility Functions.  (line   20)
* _all_matches; Function:                Control Functions.  (line   37)
* _alternative; Function:                Utility Functions.  (line   48)
* _approximate; Function:                Control Functions.  (line   64)
* _arguments; Function:                  Utility Functions.  (line   90)
* _as_if; Function:                      Utility Functions.  (line  787)
* _bash_completions; Function:           Bindable Commands.  (line   11)
* _cache_invalid; Function:              Utility Functions.  (line  795)
* _call_function; Function:              Utility Functions.  (line  812)
* _call_program; Function:               Utility Functions.  (line  822)
* _canonical_paths; Function:            Control Functions.  (line  119)
* _cdr; Function:                        Manipulating Hook Functions.
                                                             (line   91)
* _cmdambivalent; Function:              Control Functions.  (line  137)
* _cmdstring; Function:                  Control Functions.  (line  149)
* _combination; Function:                Utility Functions.  (line  856)
* _command_names; Function:              Utility Functions.  (line  899)
* _complete; Function:                   Control Functions.  (line  154)
* _completers; Function:                 Utility Functions.  (line  920)
* _complete_debug (^X?); Function:       Bindable Commands.  (line  134)
* _complete_help (^Xh); Function:        Bindable Commands.  (line  142)
* _complete_help_generic; Function:      Bindable Commands.  (line  155)
* _complete_tag (^Xt); Function:         Bindable Commands.  (line  191)
* _comp_locale; Function:                Utility Functions.  (line  908)
* _correct; Function:                    Control Functions.  (line  190)
* _correct_filename (^XC); Function:     Bindable Commands.  (line   33)
* _default; Function:                    Utility Functions.  (line  928)
* _describe; Function:                   Utility Functions.  (line  937)
* _description; Function:                Utility Functions.  (line  988)
* _dir_list; Function:                   Utility Functions.  (line 1060)
* _dispatch; Function:                   Utility Functions.  (line 1074)
* _email_addresses; Function:            Utility Functions.  (line 1088)
* _expand; Function:                     Control Functions.  (line  222)
* _expand_alias (^Xa); Function:         Bindable Commands.  (line   47)
* _expand_alias; Function:               Control Functions.  (line  252)
* _expand_word (^Xe); Function:          Bindable Commands.  (line   62)
* _extensions; Function:                 Control Functions.  (line  262)
* _external_pwds; Function:              Control Functions.  (line  271)
* _files; Function:                      Utility Functions.  (line 1118)
* _generic; Function:                    Bindable Commands.  (line   69)
* _gnu_generic; Function:                Utility Functions.  (line 1130)
* _guard; Function:                      Utility Functions.  (line 1147)
* _history; Function:                    Control Functions.  (line  280)
* _history_complete_word (\e/); Function: Bindable Commands. (line   89)
* _ignored; Function:                    Control Functions.  (line  288)
* _list; Function:                       Control Functions.  (line  298)
* _match; Function:                      Control Functions.  (line  306)
* _menu; Function:                       Control Functions.  (line  326)
* _message; Function:                    Utility Functions.  (line 1175)
* _most_recent_file (^Xm); Function:     Bindable Commands.  (line   94)
* _multi_parts; Function:                Utility Functions.  (line 1208)
* _next_label; Function:                 Utility Functions.  (line 1228)
* _next_tags (^Xn); Function:            Bindable Commands.  (line  101)
* _normal; Function:                     Utility Functions.  (line 1263)
* _numbers; Function:                    Utility Functions.  (line 1304)
* _oldlist; Function:                    Control Functions.  (line  337)
* _options; Function:                    Utility Functions.  (line 1372)
* _options_set; Function:                Utility Functions.  (line 1381)
* _options_unset; Function:              Utility Functions.  (line 1381)
* _parameters; Function:                 Utility Functions.  (line 1392)
* _path_files; Function:                 Utility Functions.  (line 1403)
* _phony; Function:                      Utility Functions.  (line 1449)
* _pick_variant; Function:               Utility Functions.  (line 1468)
* _precommand; Function:                 Control Functions.  (line  349)
* _prefix; Function:                     Control Functions.  (line  354)
* _read_comp (^X^R); Function:           Bindable Commands.  (line  109)
* _regex_arguments; Function:            Utility Functions.  (line 1497)
* _regex_words [ ‘‘-t‘‘ ;var;‘term‘ ]; Function: Utility Functions.
                                                             (line 1625)
* _requested; Function:                  Utility Functions.  (line 1678)
* _retrieve_cache; Function:             Utility Functions.  (line 1721)
* _sep_parts; Function:                  Utility Functions.  (line 1733)
* _sequence; Function:                   Utility Functions.  (line 1747)
* _setup; Function:                      Utility Functions.  (line 1761)
* _shadow; Function:                     Utility Functions.  (line 1775)
* _store_cache; Function:                Utility Functions.  (line 1831)
* _tags; Function:                       Utility Functions.  (line 1859)
* _tilde_files; Function:                Utility Functions.  (line 1879)
* _unshadow; Function:                   Utility Functions.  (line 1775)
* _user_expand; Function:                Control Functions.  (line  396)
* _values; Function:                     Utility Functions.  (line 1885)
* _wanted; Function:                     Utility Functions.  (line 1978)
* _widgets; Function:                    Utility Functions.  (line 2005)
* accept-and-hold; Type:                 Miscellaneous.      (line    6)
* accept-and-infer-next-history; Type:   Miscellaneous.      (line   10)
* accept-and-menu-complete; Type:        Completion<3>.      (line    6)
* accept-exact, completion style; Keystroke: Standard Styles.
                                                             (line   23)
* accept-exact-dirs, completion style; Keystroke: Standard Styles.
                                                             (line   47)
* accept-line-and-down-history; Type:    Miscellaneous.      (line   21)
* accept-line; Type:                     Miscellaneous.      (line   16)
* accounts, completion tag; Keystroke:   Standard Tags.      (line    9)
* acquiring zsh by FTP; Command:         Availability.       (line    8)
* actionformats; Keystroke:              Configuration<4>.   (line   81)
* add-space, completion style; Keystroke: Standard Styles.   (line   70)
* add-zle-hook-widget; Function:         Manipulating Hook Functions.
                                                             (line   41)
* add-zsh-hook; Function:                Manipulating Hook Functions.
                                                             (line    6)
* after; Function:                       Glob Qualifiers<2>. (line   82)
* age; Function:                         Glob Qualifiers<2>. (line    8)
* alias, use of; Function:               Aliasing.           (line   17)
* alias; Function:                       Shell Builtin Commands.
                                                             (line   71)
* aliases, completion of; Command:       Completion<2>.      (line   70)
* aliases, defining; Command:            Shell Builtin Commands.
                                                             (line   71)
* aliases, expanding in function definition; Command: Scripts and Functions.
                                                             (line    6)
* aliases, expansion; Command:           Input/Output.       (line    6)
* aliases, global; Command:              Aliasing.           (line   17)
* aliases, listing; Command:             Shell Builtin Commands.
                                                             (line   71)
* aliases, removing; Command:            Shell Builtin Commands.
                                                             (line 2732)
* ALIASES; Program:                      Input/Output.       (line    6)
* aliases; Variable:                     The zsh/parameter Module.
                                                             (line   93)
* ALIASFUNCDEF; Program:                 Scripts and Functions.
                                                             (line    6)
* aliasing; Command:                     Aliasing.           (line    6)
* ALIAS_FUNC_DEF; Program:               Scripts and Functions.
                                                             (line    6)
* all-expansions, completion tag; Keystroke: Standard Tags.  (line   13)
* all-files, completion tag; Keystroke:  Standard Tags.      (line   18)
* ALLEXPORT; Program:                    Initialisation.     (line    6)
* ALL_EXPORT; Program:                   Initialisation.     (line    6)
* all_quotes, compstate; Variable:       Completion Special Parameters.
                                                             (line   80)
* alternate forms for complex commands; Command: Alternate Forms For Complex Commands.
                                                             (line    6)
* always blocks; Command:                Complex Commands.   (line  123)
* always; Function:                      Complex Commands.   (line  123)
* ALWAYSLASTPROMPT; Program:             Completion<2>.      (line    6)
* ALWAYSTOEND; Program:                  Completion<2>.      (line   12)
* ALWAYS_LAST_PROMPT; Program:           Completion<2>.      (line    6)
* ALWAYS_TO_END; Program:                Completion<2>.      (line   12)
* ambiguous completion; Command:         Completion<2>.      (line  105)
* ambiguous, completion style; Keystroke: Standard Styles.   (line   84)
* annoying keyboard, sun; Command:       Input/Output.       (line  173)
* anonymous functions; Command:          Anonymous Functions.
                                                             (line    6)
* APPENDCREATE; Program:                 Shell Emulation.    (line    6)
* APPENDHISTORY; Program:                History.            (line    6)
* APPEND_CREATE; Program:                Shell Emulation.    (line    6)
* APPEND_HISTORY; Program:               History.            (line    6)
* approximate matching; Command:         Approximate Matching.
                                                             (line    6)
* ARGC; Variable:                        Parameters Set by the Shell.
                                                             (line   32)
* argument splitting, in typeset etc.; Command: Shell Emulation.
                                                             (line   96)
* argument-base; Type:                   Arguments.          (line   33)
* arguments, completion tag; Keystroke:  Standard Tags.      (line   23)
* ARGV0; Variable:                       Parameters Used by the Shell.
                                                             (line   21)
* argv; Variable:                        Parameters Set by the Shell.
                                                             (line   53)
* arithmetic base; Command:              Arithmetic Evaluation.
                                                             (line   37)
* arithmetic evaluation; Command:        Arithmetic Evaluation.
                                                             (line    6)
* arithmetic expansion; Command:         Arithmetic Expansion.
                                                             (line    6)
* arithmetic operators; Command:         Arithmetic Evaluation.
                                                             (line  138)
* array assignment; Command:             Array Parameters.   (line    9)
* array expansion style, rc; Command:    Parameter Expansion.
                                                             (line  333)
* array parameters, setting; Command:    Shell Builtin Commands.
                                                             (line 1878)
* array parameters; Command:             Description<2>.     (line   83)
* array style, ksh; Command:             Shell Emulation.    (line   71)
* arrays, behaviour of index zero; Command: Shell Emulation. (line  111)
* arrays, completion tag; Keystroke:     Standard Tags.      (line   27)
* arrays, ksh style; Command:            Shell Emulation.    (line   71)
* assign-list, completion style; Keystroke: Standard Styles. (line   92)
* association-keys, completion tag; Keystroke: Standard Tags.
                                                             (line   31)
* asynchronous jobs, and exiting shell; Command: Signals.    (line   12)
* author; Command:                       Author.             (line    6)
* auto-description, completion style; Keystroke: Standard Styles.
                                                             (line  104)
* auto-suffix-remove; Type:              Miscellaneous.      (line   26)
* auto-suffix-retain; Type:              Miscellaneous.      (line   36)
* autocd, silencing; Command:            Changing Directories.
                                                             (line   27)
* AUTOCD; Program:                       Changing Directories.
                                                             (line    6)
* AUTOCONTINUE; Program:                 Job Control.        (line    6)
* AUTOLIST; Program:                     Completion<2>.      (line   19)
* autoload, use of; Function:            Autoloading Functions.
                                                             (line    6)
* autoload; Function:                    Shell Builtin Commands.
                                                             (line  120)
* autoloading functions; Command:        Autoloading Functions.
                                                             (line    6)
* autoloading functions; Command <1>:    Shell Builtin Commands.
                                                             (line  120)
* AUTOMENU; Program:                     Completion<2>.      (line   23)
* AUTONAMEDIRS; Program:                 Completion<2>.      (line   29)
* AUTOPARAMKEYS; Program:                Completion<2>.      (line   37)
* AUTOPARAMSLASH; Program:               Completion<2>.      (line   48)
* AUTOPUSHD; Program:                    Changing Directories.
                                                             (line   16)
* AUTOREMOVESLASH; Program:              Completion<2>.      (line   53)
* AUTORESUME; Program:                   Job Control.        (line   12)
* AUTO_CD; Program:                      Changing Directories.
                                                             (line    6)
* AUTO_CONTINUE; Program:                Job Control.        (line    6)
* AUTO_LIST; Program:                    Completion<2>.      (line   19)
* AUTO_MENU; Program:                    Completion<2>.      (line   23)
* AUTO_NAME_DIRS; Program:               Completion<2>.      (line   29)
* AUTO_PARAM_KEYS; Program:              Completion<2>.      (line   37)
* AUTO_PARAM_SLASH; Program:             Completion<2>.      (line   48)
* AUTO_PUSHD; Program:                   Changing Directories.
                                                             (line   16)
* AUTO_REMOVE_SLASH; Program:            Completion<2>.      (line   53)
* AUTO_RESUME; Program:                  Job Control.        (line   12)
* availability of zsh; Command:          Availability.       (line    8)
* avoid-completer, completion style; Keystroke: Standard Styles.
                                                             (line  114)
* background jobs, notification; Command: Job Control.       (line   55)
* background jobs, priority of; Command: Job Control.        (line   17)
* backward-char; Type:                   Movement.           (line   16)
* backward-delete-char; Type:            Modifying Text.     (line   15)
* backward-delete-word; Type:            Modifying Text.     (line   25)
* backward-kill-line; Type:              Modifying Text.     (line   29)
* backward-kill-word-match; Type:        Widgets.            (line   28)
* backward-kill-word; Type:              Modifying Text.     (line   33)
* backward-word-match; Type:             Widgets.            (line   28)
* backward-word; Type:                   Movement.           (line   24)
* BADPATTERN; Program:                   Expansion and Globbing.
                                                             (line    6)
* BAD_PATTERN; Program:                  Expansion and Globbing.
                                                             (line    6)
* BANGHIST; Program:                     History.            (line   16)
* BANG_HIST; Program:                    History.            (line   16)
* BAREGLOBQUAL; Program:                 Expansion and Globbing.
                                                             (line   12)
* BARE_GLOB_QUAL, use of; Program:       Glob Qualifiers.    (line   10)
* BARE_GLOB_QUAL; Program:               Expansion and Globbing.
                                                             (line   12)
* bases, in arithmetic; Command:         Arithmetic Evaluation.
                                                             (line   37)
* bases, output in C format; Command:    Scripts and Functions.
                                                             (line   32)
* bash, BASH_REMATCH variable; Command:  Shell Emulation.    (line   15)
* BASHAUTOLIST; Program:                 Completion<2>.      (line   60)
* bashcompinit; Function:                Use of compinit.    (line   77)
* BASHREMATCH; Program:                  Shell Emulation.    (line   15)
* BASH_AUTO_LIST; Program:               Completion<2>.      (line   60)
* BASH_REMATCH; Program:                 Shell Emulation.    (line   15)
* BAUD, use of; Variable:                Description<3>.     (line   20)
* BAUD; Variable:                        Parameters Used by the Shell.
                                                             (line   26)
* beep, ambiguous completion; Command:   Completion<2>.      (line  114)
* beep, enabling; Command:               Zle.                (line    6)
* beep, history; Command:                History.            (line   34)
* BEEP; Program:                         Zle.                (line    6)
* beep; Type:                            Miscellaneous.      (line   46)
* before; Function:                      Glob Qualifiers<2>. (line   82)
* beginning-of-buffer-or-history; Type:  History Control.    (line    6)
* beginning-of-history; Type:            History Control.    (line   16)
* beginning-of-line-hist; Type:          History Control.    (line   11)
* beginning-of-line; Type:               Movement.           (line   40)
* bg, output in POSIX format; Command:   Job Control.        (line   60)
* bg; Function:                          Shell Builtin Commands.
                                                             (line  202)
* BGNICE; Program:                       Job Control.        (line   17)
* BG_NICE; Program:                      Job Control.        (line   17)
* binding keys; Command:                 Zle Builtins.       (line   12)
* binding widgets; Command:              Zle Builtins.       (line  296)
* bindings, key; Command:                Keymaps.            (line    6)
* bindkey; Function:                     Zle Builtins.       (line   12)
* bookmarks, completion tag; Keystroke:  Standard Tags.      (line   36)
* brace expansion, disabling; Command:   Expansion and Globbing.
                                                             (line  124)
* brace expansion, extending; Command:   Expansion and Globbing.
                                                             (line   18)
* brace expansion; Command:              Brace Expansion.    (line    6)
* BRACECCL; Program:                     Expansion and Globbing.
                                                             (line   18)
* BRACEEXPAND; Program:                  Option Aliases.     (line   10)
* BRACE_CCL; Program:                    Expansion and Globbing.
                                                             (line   18)
* BRACE_EXPAND; Program:                 Option Aliases.     (line   10)
* bracketed paste; Command:              Parameters Used by the Shell.
                                                             (line  698)
* bracketed-paste-magic; Type:           Widgets.            (line  289)
* bracketed-paste-url-magic; Type:       Widgets.            (line  391)
* bracketed-paste; Type:                 Miscellaneous.      (line   50)
* branchformat; Keystroke:               Configuration<4>.   (line   87)
* break, inside function; Command:       Scripts and Functions.
                                                             (line  142)
* break-keys, widget style; Keystroke:   Styles<2>.          (line   11)
* break; Function:                       Shell Builtin Commands.
                                                             (line  213)
* BSDECHO; Program:                      Shell Emulation.    (line   27)
* BSD_ECHO, use of; Program:             Shell Builtin Commands.
                                                             (line  567)
* BSD_ECHO; Program:                     Shell Emulation.    (line   27)
* BUFFER; Variable:                      User-Defined Widgets.
                                                             (line   39)
* BUFFERLINES; Variable:                 User-Defined Widgets.
                                                             (line   45)
* builtin commands; Command:             Shell Builtin Commands.
                                                             (line    6)
* builtin; Function:                     Precommand Modifiers.
                                                             (line   16)
* builtin; Function <1>:                 Shell Builtin Commands.
                                                             (line  219)
* builtins, completion tag; Keystroke:   Standard Tags.      (line   41)
* builtins, utility; Command:            The zsh/zutil Module.
                                                             (line    6)
* builtins; Variable:                    The zsh/parameter Module.
                                                             (line   65)
* bye; Function:                         Shell Builtin Commands.
                                                             (line  223)
* cache-path, completion style; Keystroke: Standard Styles.  (line  127)
* cache-policy, completion style; Keystroke: Standard Styles.
                                                             (line  135)
* calendar function system; Command:     Calendar Function System.
                                                             (line    6)
* calendar-file; Keystroke:              Styles.             (line   13)
* calendar; Function:                    Calendar System Functions.
                                                             (line    6)
* calendar_add; Function:                Calendar System Functions.
                                                             (line  176)
* calendar_edit; Function:               Calendar System Functions.
                                                             (line  229)
* calendar_lockfiles; Function:          Utility functions.  (line    6)
* calendar_parse; Function:              Calendar System Functions.
                                                             (line  246)
* calendar_read; Function:               Utility functions.  (line   32)
* calendar_scandate; Function:           Utility functions.  (line   40)
* calendar_show; Function:               Utility functions.  (line  103)
* calendar_showdate; Function:           Calendar System Functions.
                                                             (line  309)
* calendar_sort; Function:               Calendar System Functions.
                                                             (line  331)
* call-command, completion style; Keystroke: Standard Styles.
                                                             (line  141)
* calling widgets; Command:              Zle Builtins.       (line  296)
* cap; Function:                         The zsh/cap Module. (line   11)
* capabilities, getting from files; Command: The zsh/cap Module.
                                                             (line   16)
* capabilities, setting on files; Command: The zsh/cap Module.
                                                             (line   21)
* capabilities, setting; Command:        The zsh/cap Module. (line   11)
* capitalize-word-match; Type:           Widgets.            (line   28)
* capitalize-word; Type:                 Modifying Text.     (line   42)
* case selection; Command:               Complex Commands.   (line   66)
* case-insensitive globbing, option; Command: Expansion and Globbing.
                                                             (line   24)
* case-insensitive regular expression matches, option; Command: Expansion and Globbing.
                                                             (line   34)
* case-sensitive globbing, option; Command: Expansion and Globbing.
                                                             (line   39)
* case; Function:                        Complex Commands.   (line   66)
* CASEGLOB; Program:                     Expansion and Globbing.
                                                             (line   24)
* CASEMATCH; Program:                    Expansion and Globbing.
                                                             (line   34)
* CASEPATHS; Program:                    Expansion and Globbing.
                                                             (line   39)
* CASE_GLOB; Program:                    Expansion and Globbing.
                                                             (line   24)
* CASE_MATCH; Program:                   Expansion and Globbing.
                                                             (line   34)
* CASE_PATHS; Program:                   Expansion and Globbing.
                                                             (line   39)
* CBASES; Program:                       Scripts and Functions.
                                                             (line   32)
* cd, automatic; Command:                Changing Directories.
                                                             (line    6)
* cd, behaving like pushd; Command:      Changing Directories.
                                                             (line   16)
* cd, silencing; Command:                Changing Directories.
                                                             (line   27)
* cd, to parameter; Command:             Changing Directories.
                                                             (line   20)
* cd, with .. in argument; Command:      Changing Directories.
                                                             (line   37)
* cd; Function:                          Shell Builtin Commands.
                                                             (line  231)
* CDABLEVARS; Program:                   Changing Directories.
                                                             (line   20)
* CDABLE_VARS, use of; Program:          Shell Builtin Commands.
                                                             (line 1651)
* CDABLE_VARS; Program:                  Changing Directories.
                                                             (line   20)
* CDPATH, order of checking; Command:    Changing Directories.
                                                             (line   60)
* cdpath; Variable:                      Parameters Used by the Shell.
                                                             (line   39)
* CDPATH; Variable:                      Parameters Used by the Shell.
                                                             (line   39)
* cdr; Function:                         Manipulating Hook Functions.
                                                             (line   91)
* CDSILENT; Program:                     Changing Directories.
                                                             (line   27)
* CD_SILENT; Program:                    Changing Directories.
                                                             (line   27)
* characters, (Unicode) combining; Command: Zle.             (line   10)
* characters, completion tag; Keystroke: Standard Tags.      (line   45)
* characters, multibyte, in expansion and globbing; Command: Expansion and Globbing.
                                                             (line  176)
* CHASEDOTS; Program:                    Changing Directories.
                                                             (line   37)
* CHASELINKS; Program:                   Changing Directories.
                                                             (line   53)
* CHASE_DOTS; Program:                   Changing Directories.
                                                             (line   37)
* CHASE_LINKS, use of; Program:          Shell Builtin Commands.
                                                             (line 1690)
* CHASE_LINKS; Program:                  Changing Directories.
                                                             (line   53)
* chdir; Function:                       Shell Builtin Commands.
                                                             (line  287)
* check-for-changes; Keystroke:          Configuration<4>.   (line  178)
* check-for-staged-changes; Keystroke:   Configuration<4>.   (line  198)
* CHECKJOBS; Program:                    Job Control.        (line   22)
* CHECKRUNNINGJOBS; Program:             Job Control.        (line   35)
* CHECK_JOBS; Program:                   Job Control.        (line   22)
* CHECK_RUNNING_JOBS; Program:           Job Control.        (line   35)
* chgrp; Function:                       The zsh/files Module.
                                                             (line   21)
* chmod; Function:                       The zsh/files Module.
                                                             (line   26)
* chown; Function:                       The zsh/files Module.
                                                             (line   46)
* chpwd, zftp style; Keystroke:          Configuration.      (line   62)
* chpwd; Function:                       Hook Functions.     (line   21)
* chpwd_functions; Variable:             Hook Functions.     (line   21)
* chpwd_recent_add; Function:            Manipulating Hook Functions.
                                                             (line   91)
* chpwd_recent_dirs; Function:           Manipulating Hook Functions.
                                                             (line   91)
* chpwd_recent_filehandler; Function:    Manipulating Hook Functions.
                                                             (line   90)
* clear-screen; Type:                    Miscellaneous.      (line   82)
* CLOBBER; Program:                      Input/Output.       (line   10)
* CLOBBEREMPTY; Program:                 Input/Output.       (line   19)
* clobbering, of empty files; Command:   Input/Output.       (line   19)
* clobbering, of files; Command:         Input/Output.       (line   10)
* clobbering, POSIX compatibility; Command: Shell Emulation. (line    6)
* CLOBBER_EMPTY; Program:                Input/Output.       (line   19)
* clone; Function:                       The zsh/clone Module.
                                                             (line    8)
* cloning the shell; Command:            The zsh/clone Module.
                                                             (line    8)
* colon modifiers; Command:              Modifiers.          (line    6)
* colormapids, completion tag; Keystroke: Standard Tags.     (line   51)
* colors, completion tag; Keystroke:     Standard Tags.      (line   55)
* colors; Function:                      Descriptions.       (line    6)
* COLUMNS, use of; Variable:             Description<3>.     (line   20)
* COLUMNS; Variable:                     Parameters Used by the Shell.
                                                             (line   44)
* combining characters (Unicode); Command: Zle.              (line   10)
* COMBININGCHARS; Program:               Zle.                (line   10)
* COMBINING_CHARS; Program:              Zle.                (line   10)
* command execution, enabling; Command:  Scripts and Functions.
                                                             (line  127)
* command execution; Command:            Command Execution.  (line    6)
* command hashing; Command:              Input/Output.       (line   81)
* command not found, handling of; Command: Command Execution.
                                                             (line    6)
* command substitution; Command:         Command Substitution.
                                                             (line    6)
* command, completion style; Keystroke:  Standard Styles.    (line  150)
* command-path, completion style; Keystroke: Standard Styles.
                                                             (line  178)
* command; Function:                     Precommand Modifiers.
                                                             (line   21)
* command; Function <1>:                 Shell Builtin Commands.
                                                             (line  295)
* command; Keystroke:                    Configuration<4>.   (line  221)
* commands, alternate forms for complex; Command: Alternate Forms For Complex Commands.
                                                             (line    6)
* commands, builtin; Command:            Shell Builtin Commands.
                                                             (line    6)
* commands, completion style; Keystroke: Standard Styles.    (line  184)
* commands, completion tag; Keystroke:   Standard Tags.      (line   59)
* commands, complex; Command:            Complex Commands.   (line    6)
* commands, disabling; Command:          Shell Builtin Commands.
                                                             (line  385)
* commands, enabling; Command:           Shell Builtin Commands.
                                                             (line  702)
* commands, simple; Command:             Simple Commands & Pipelines.
                                                             (line    6)
* commands, tracing; Command:            Scripts and Functions.
                                                             (line  256)
* commands; Variable:                    The zsh/parameter Module.
                                                             (line   19)
* command_not_found_handler; Function:   Command Execution.  (line    6)
* comments, in interactive shells; Command: Input/Output.    (line   77)
* comments; Command:                     Comments.           (line    6)
* compadd; Function:                     Completion Builtin Commands.
                                                             (line    6)
* comparguments; Function:               The zsh/computil Module.
                                                             (line   12)
* compatibility, csh; Command:           Shell Builtin Commands.
                                                             (line  588)
* compatibility, ksh; Command:           Shell Builtin Commands.
                                                             (line  588)
* compatibility, sh; Command:            Shell Builtin Commands.
                                                             (line  588)
* compatibility; Command:                Compatibility.      (line    6)
* compaudit; Function:                   Use of compinit.    (line   67)
* compdef, use of by compinit; Command:  Autoloaded Files.   (line   21)
* compdef; Function:                     Functions<2>.       (line    9)
* compdescribe; Function:                The zsh/computil Module.
                                                             (line   20)
* compfiles; Function:                   The zsh/computil Module.
                                                             (line   42)
* compgroups; Function:                  The zsh/computil Module.
                                                             (line   54)
* compilation; Command:                  Shell Builtin Commands.
                                                             (line 2923)
* compinit; Function:                    Use of compinit.    (line    6)
* compinstall; Function:                 Initialization.     (line    6)
* complete, completion style; Keystroke: Standard Styles.    (line  193)
* complete-options, completion style; Keystroke: Standard Styles.
                                                             (line  200)
* complete-word; Type:                   Completion<3>.      (line   11)
* COMPLETEALIASES; Program:              Completion<2>.      (line   70)
* COMPLETEINWORD; Program:               Completion<2>.      (line   76)
* completer, completion style; Keystroke: Standard Styles.   (line  210)
* completer, completion style; Keystroke <1>: Styles<2>.     (line   20)
* COMPLETE_ALIASES; Program:             Completion<2>.      (line   70)
* COMPLETE_IN_WORD; Program:             Completion<2>.      (line   76)
* completion removable suffix, highlighting; Command: Character Highlighting.
                                                             (line   47)
* completion system, adding definitions; Command: Functions<2>.
                                                             (line    9)
* completion system, autoloaded functions; Command: Autoloaded Files.
                                                             (line    6)
* completion system, bindable commands; Command: Bindable Commands.
                                                             (line    6)
* completion system, choosing completers; Command: Control Functions.
                                                             (line    6)
* completion system, completers; Command: Control Functions. (line   37)
* completion system, configuration; Command: Completion System Configuration.
                                                             (line    6)
* completion system, directory structure; Command: Completion Directories.
                                                             (line    6)
* completion system, initializing; Command: Use of compinit. (line    6)
* completion system, installing; Command: Initialization.    (line    6)
* completion system, styles; Command:    Standard Styles.    (line    6)
* completion system, tags; Command:      Standard Tags.      (line    6)
* completion system, utility functions; Command: Utility Functions.
                                                             (line    6)
* completion system, variables; Command: Completion System Variables.
                                                             (line    6)
* completion system; Command:            Completion System.  (line    6)
* completion widgets, adding specified matches; Command: Completion Builtin Commands.
                                                             (line    6)
* completion widgets, condition codes; Command: Completion Condition Codes.
                                                             (line    6)
* completion widgets, creating; Command: Zle Builtins.       (line  408)
* completion widgets, examining and setting state in; Command: Completion Special Parameters.
                                                             (line   74)
* completion widgets, example; Command:  Completion Widget Example.
                                                             (line    6)
* completion widgets, modifying special parameters; Command: Completion Builtin Commands.
                                                             (line  374)
* completion, ambiguous; Command:        Completion<2>.      (line  105)
* completion, beep on ambiguous; Command: Completion<2>.     (line  114)
* completion, coloured listings; Command: The zsh/complist Module.
                                                             (line    6)
* completion, controlling; Command:      Completion Widgets. (line    6)
* completion, controlling; Command <1>:  Completion System.  (line    6)
* completion, controlling; Command <2>:  Completion Using compctl.
                                                             (line    6)
* completion, exact matches; Command:    Completion<2>.      (line  147)
* completion, listing choices, bash style; Command: Completion<2>.
                                                             (line   60)
* completion, listing choices; Command:  Completion<2>.      (line   19)
* completion, listing order; Command:    Completion<2>.      (line  127)
* completion, listing; Command:          Completion<2>.      (line  122)
* completion, listing; Command <1>:      The zsh/complist Module.
                                                             (line    6)
* completion, menu; Command:             Completion<2>.      (line   23)
* completion, menu; Command <1>:         Completion<2>.      (line  138)
* completion, programmable; Command:     Completion Widgets. (line    6)
* completion, programmable; Command <1>: Completion System.  (line    6)
* completion, programmable; Command <2>: Completion Using compctl.
                                                             (line    6)
* completion, scroll listings; Command:  The zsh/complist Module.
                                                             (line    6)
* completion, selecting by cursor; Command: Menu Selection.  (line    6)
* completion, utility; Command:          The zsh/computil Module.
                                                             (line    6)
* completion, widgets; Command:          Completion Widgets. (line    6)
* complex commands; Command:             Complex Commands.   (line    6)
* comppostfuncs, use of; Variable:       Completion System Variables.
                                                             (line   29)
* compprefuncs, use of; Variable:        Completion System Variables.
                                                             (line   29)
* compquote; Function:                   The zsh/computil Module.
                                                             (line   62)
* compset; Function:                     Completion Builtin Commands.
                                                             (line  374)
* compstate; Variable:                   Completion Special Parameters.
                                                             (line   74)
* comptags; Function:                    The zsh/computil Module.
                                                             (line   78)
* comptry; Function:                     The zsh/computil Module.
                                                             (line   78)
* compvalues; Function:                  The zsh/computil Module.
                                                             (line   84)
* condition, completion style; Keystroke: Standard Styles.   (line  241)
* conditional expression; Command:       Complex Commands.   (line  223)
* conditional expressions; Command:      Conditional Expressions.
                                                             (line    6)
* context, compstate; Variable:          Completion Special Parameters.
                                                             (line   95)
* context, use of; Variable:             Utility Functions.  (line  463)
* CONTEXT; Variable:                     User-Defined Widgets.
                                                             (line   51)
* contexts, completion tag; Keystroke:   Standard Tags.      (line   64)
* continue, inside function; Command:    Scripts and Functions.
                                                             (line  142)
* continue; Function:                    Shell Builtin Commands.
                                                             (line  347)
* CONTINUEONERROR; Program:              Shell Emulation.    (line   33)
* CONTINUE_ON_ERROR; Program:            Shell Emulation.    (line   33)
* continuing jobs automatically; Command: Job Control.       (line    6)
* continuing loops; Command:             Shell Builtin Commands.
                                                             (line  347)
* coproc; Function:                      Simple Commands & Pipelines.
                                                             (line   36)
* coprocess; Command:                    Simple Commands & Pipelines.
                                                             (line   36)
* copy-earlier-word; Type:               Widgets.            (line  419)
* copy-prev-shell-word; Type:            Modifying Text.     (line   80)
* copy-prev-word; Type:                  Modifying Text.     (line   76)
* copy-region-as-kill; Type:             Modifying Text.     (line   67)
* CORRECT; Program:                      Input/Output.       (line   31)
* CORRECTALL; Program:                   Input/Output.       (line   44)
* correction, spelling; Command:         Input/Output.       (line   31)
* corrections, completion tag; Keystroke: Standard Tags.     (line   68)
* CORRECT_ALL; Program:                  Input/Output.       (line   44)
* CORRECT_IGNORE; Variable:              Parameters Used by the Shell.
                                                             (line   55)
* CORRECT_IGNORE_FILE; Variable:         Parameters Used by the Shell.
                                                             (line   66)
* CPRECEDENCES; Program:                 Scripts and Functions.
                                                             (line   43)
* CPUTYPE; Variable:                     Parameters Set by the Shell.
                                                             (line  100)
* csh, compatibility; Command:           Shell Builtin Commands.
                                                             (line  588)
* csh, history style; Command:           Shell Emulation.    (line   43)
* csh, loop style; Command:              Shell Emulation.    (line   51)
* csh, null command style; Command:      Parameters Used by the Shell.
                                                             (line  324)
* csh, null globbing style; Command:     Expansion and Globbing.
                                                             (line   52)
* csh, quoting style; Command:           Shell Emulation.    (line   56)
* csh, redirections with no command; Command: Shell Emulation.
                                                             (line   65)
* CSHJUNKIEHISTORY; Program:             Shell Emulation.    (line   43)
* CSHJUNKIELOOPS; Program:               Shell Emulation.    (line   51)
* CSHJUNKIEQUOTES; Program:              Shell Emulation.    (line   56)
* CSHNULLCMD; Program:                   Shell Emulation.    (line   65)
* CSHNULLGLOB; Program:                  Expansion and Globbing.
                                                             (line   52)
* CSH_JUNKIE_HISTORY; Program:           Shell Emulation.    (line   43)
* CSH_JUNKIE_LOOPS; Program:             Shell Emulation.    (line   51)
* CSH_JUNKIE_QUOTES; Program:            Shell Emulation.    (line   56)
* CSH_NULLCMD, use of; Program:          Redirections with no command.
                                                             (line   10)
* CSH_NULLCMD; Program:                  Shell Emulation.    (line   65)
* CSH_NULL_GLOB; Program:                Expansion and Globbing.
                                                             (line   52)
* cube; Function:                        Shell Builtin Commands.
                                                             (line  994)
* current-shell, MIME style; Keystroke:  MIME Functions.     (line   76)
* CURRENT; Variable:                     Completion Special Parameters.
                                                             (line   21)
* cursor color; Command:                 Cursor Shape and Color.
                                                             (line    6)
* cursor shape; Command:                 Cursor Shape and Color.
                                                             (line    6)
* cursor, completion style; Keystroke:   Styles<2>.          (line   45)
* CURSOR; Variable:                      User-Defined Widgets.
                                                             (line   72)
* cursors, completion tag; Keystroke:    Standard Tags.      (line   73)
* CUTBUFFER; Variable:                   User-Defined Widgets.
                                                             (line   79)
* cycle-completion-positions; Type:      Widgets.            (line  436)
* C_BASES, use of; Program:              Arithmetic Evaluation.
                                                             (line   93)
* C_BASES; Program:                      Scripts and Functions.
                                                             (line   32)
* C_PRECEDENCES; Program:                Scripts and Functions.
                                                             (line   43)
* database file path, reading; Command:  The zsh/db/gdbm Module.
                                                             (line   48)
* database tied array, creating; Command: The zsh/db/gdbm Module.
                                                             (line   15)
* database tied array, destroying; Command: The zsh/db/gdbm Module.
                                                             (line   37)
* database tied arrays, enumerating; Command: The zsh/db/gdbm Module.
                                                             (line   53)
* date string, printing; Command:        The zsh/datetime Module.
                                                             (line    8)
* date-format; Keystroke:                Styles.             (line   17)
* deactivate-region; Type:               Miscellaneous.      (line   86)
* DEBUG trap, before or after command; Command: Scripts and Functions.
                                                             (line   49)
* debug; Keystroke:                      Configuration<4>.   (line  303)
* DEBUGBEFORECMD; Program:               Scripts and Functions.
                                                             (line   49)
* DEBUG_BEFORE_CMD; Program:             Scripts and Functions.
                                                             (line   49)
* declare; Function:                     Shell Builtin Commands.
                                                             (line  354)
* default, completion tag; Keystroke:    Standard Tags.      (line   77)
* defining widgets; Command:             Zle Builtins.       (line  296)
* delete-char-or-list; Type:             Completion<3>.      (line   15)
* delete-char; Type:                     Modifying Text.     (line   92)
* delete-to-char; Type:                  The zsh/deltochar Module.
                                                             (line    8)
* delete-whole-word-match; Type:         Widgets.            (line   28)
* delete-whole-word-match; Type <1>:     Widgets.            (line  450)
* delete-word; Type:                     Modifying Text.     (line  101)
* delimiters, completion style; Keystroke: Standard Styles.  (line  247)
* describe-key-briefly; Type:            Miscellaneous.      (line   91)
* descriptions, completion tag; Keystroke: Standard Tags.    (line   83)
* descriptors, file; Command:            Redirection.        (line    6)
* devices, completion tag; Keystroke:    Standard Tags.      (line   88)
* digit-argument; Type:                  Arguments.          (line    6)
* directories, changing; Command:        Shell Builtin Commands.
                                                             (line  231)
* directories, completion tag; Keystroke: Standard Tags.     (line   92)
* directories, hashing; Command:         Input/Output.       (line   90)
* directories, maintaining list of recent; Command: Manipulating Hook Functions.
                                                             (line   91)
* directories, marking; Command:         Expansion and Globbing.
                                                             (line  171)
* directories, named, dynamic, helper function; Command: Details of Directory Handling.
                                                             (line   25)
* directories, named, dynamic; Command:  Dynamic Named Directories.
                                                             (line    6)
* directories, named, static; Command:   Static Named Directories.
                                                             (line    6)
* directories, named; Command:           Completion<2>.      (line   29)
* directory stack, controlling syntax; Command: Changing Directories.
                                                             (line   84)
* directory stack, ignoring duplicates; Command: Changing Directories.
                                                             (line   79)
* directory stack, printing; Command:    Shell Builtin Commands.
                                                             (line  358)
* directory stack, silencing; Command:   Changing Directories.
                                                             (line   89)
* directory-stack, completion tag; Keystroke: Standard Tags. (line   98)
* dirs; Function:                        Shell Builtin Commands.
                                                             (line  358)
* dirstack; Variable:                    The zsh/parameter Module.
                                                             (line  145)
* DIRSTACKSIZE; Variable:                Parameters Used by the Shell.
                                                             (line   74)
* disable, use of; Function:             Reserved Words.     (line    6)
* disable-patterns; Keystroke:           Configuration<4>.   (line  131)
* disable; Function:                     Shell Builtin Commands.
                                                             (line  385)
* disable; Keystroke:                    Configuration<4>.   (line  125)
* disabled, completion style; Keystroke: Standard Styles.    (line  256)
* disabling brace expansion; Command:    Expansion and Globbing.
                                                             (line  124)
* disabling commands; Command:           Shell Builtin Commands.
                                                             (line  385)
* discarding embedded nulls in $’...’; Command: Shell Emulation.
                                                             (line  232)
* disown, MIME style; Keystroke:         MIME Functions.     (line   84)
* disown, use of; Function:              Jobs.               (line  120)
* disown; Function:                      Shell Builtin Commands.
                                                             (line  488)
* disowning jobs; Command:               Jobs.               (line  120)
* displays, completion tag; Keystroke:   Standard Tags.      (line  102)
* dis_aliases; Variable:                 The zsh/parameter Module.
                                                             (line   98)
* dis_builtins; Variable:                The zsh/parameter Module.
                                                             (line   73)
* dis_functions; Variable:               The zsh/parameter Module.
                                                             (line   37)
* dis_functions_source; Variable:        The zsh/parameter Module.
                                                             (line   61)
* dis_galiases; Variable:                The zsh/parameter Module.
                                                             (line  106)
* dis_patchars; Variable:                The zsh/parameter Module.
                                                             (line   89)
* dis_reswords; Variable:                The zsh/parameter Module.
                                                             (line   81)
* dis_saliases; Variable:                The zsh/parameter Module.
                                                             (line  114)
* doing nothing, successfully; Command:  Shell Builtin Commands.
                                                             (line 2086)
* doing nothing, unsuccessfully; Command: Shell Builtin Commands.
                                                             (line  771)
* doing nothing; Command:                Shell Builtin Commands.
                                                             (line   65)
* domains, completion style; Keystroke:  Standard Styles.    (line  262)
* domains, completion tag; Keystroke:    Standard Tags.      (line  106)
* done-file; Keystroke:                  Styles.             (line   33)
* DOTGLOB; Program:                      Option Aliases.     (line   14)
* DOT_GLOB; Program:                     Option Aliases.     (line   14)
* down-case-word-match; Type:            Widgets.            (line   28)
* down-case-word; Type:                  Modifying Text.     (line  105)
* down-history; Type:                    History Control.    (line   41)
* down-line-or-beginning-search; Type:   Widgets.            (line  468)
* down-line-or-history; Type:            History Control.    (line   20)
* down-line-or-search; Type:             History Control.    (line   31)
* down-line; Type:                       Movement.           (line   49)
* DVORAK; Program:                       Input/Output.       (line   54)
* dynamic directory naming, helper function; Command: Details of Directory Handling.
                                                             (line   25)
* dynamic named directories; Command:    Dynamic Named Directories.
                                                             (line    6)
* echo, BSD compatible; Command:         Shell Emulation.    (line   27)
* echo; Function:                        Shell Builtin Commands.
                                                             (line  505)
* echotc; Function:                      The zsh/termcap Module.
                                                             (line    8)
* echoti; Function:                      The zsh/terminfo Module.
                                                             (line    8)
* edit-command-line; Type:               Widgets.            (line  479)
* editing history; Command:              Shell Builtin Commands.
                                                             (line  775)
* editing over slow connection; Command: Parameters Used by the Shell.
                                                             (line   26)
* editing parameters; Command:           Zle Builtins.       (line  244)
* editor ksh style; Command:             Description<3>.     (line   17)
* editor, enabling; Command:             Zle.                (line   60)
* editor, line; Command:                 Zsh Line Editor.    (line    6)
* editor, overstrike mode; Command:      Zle.                (line   36)
* editor, single line mode; Command:     Zle.                (line   40)
* EDITOR; Variable:                      Keymaps.            (line   54)
* EGID; Variable:                        Parameters Set by the Shell.
                                                             (line  105)
* eight bit characters, printing; Command: Input/Output.     (line  133)
* emacs-backward-word; Type:             Movement.           (line   28)
* emacs-forward-word; Type:              Movement.           (line  116)
* EMACS; Program:                        Zle.                (line   26)
* email-*, completion tag; Keystroke:    Standard Tags.      (line  110)
* embedded nulls, in $’...’; Command:    Shell Emulation.    (line  232)
* emulate; Function:                     Shell Builtin Commands.
                                                             (line  588)
* enable globbing qualifiers; Command:   Expansion and Globbing.
                                                             (line   12)
* enable history substitution; Command:  History.            (line   16)
* enable; Function:                      Shell Builtin Commands.
                                                             (line  702)
* enable; Keystroke:                     Configuration<4>.   (line  116)
* enabling bracketed paste; Command:     Parameters Used by the Shell.
                                                             (line  698)
* enabling commands; Command:            Shell Builtin Commands.
                                                             (line  702)
* enabling globbing; Command:            Expansion and Globbing.
                                                             (line   76)
* enabling the beep; Command:            Zle.                (line    6)
* enabling the editor; Command:          Zle.                (line   60)
* end-of-buffer-or-history; Type:        History Control.    (line   51)
* end-of-history; Type:                  History Control.    (line   61)
* end-of-line-hist; Type:                History Control.    (line   56)
* end-of-line; Type:                     Movement.           (line   53)
* end-of-list; Type:                     Completion<3>.      (line   69)
* ENV, use of; Variable:                 Compatibility.      (line   20)
* ENV; Variable:                         Parameters Used by the Shell.
                                                             (line   81)
* environ, completion style; Keystroke:  Standard Styles.    (line  267)
* environment variables; Command:        Description<2>.     (line   24)
* environment, and local parameters; Command: Initialisation.
                                                             (line   10)
* environment; Command:                  Description<2>.     (line   24)
* EOF, ignoring; Command:                Input/Output.       (line   66)
* EPOCHREALTIME; Variable:               The zsh/datetime Module.
                                                             (line   66)
* EPOCHSECONDS; Variable:                The zsh/datetime Module.
                                                             (line   74)
* epochtime; Variable:                   The zsh/datetime Module.
                                                             (line   79)
* EQUALS; Program:                       Expansion and Globbing.
                                                             (line   58)
* ERREXIT; Program:                      Scripts and Functions.
                                                             (line   55)
* ERRNO; Variable:                       Parameters Set by the Shell.
                                                             (line  127)
* errnos; Variable:                      Parameters<4>.      (line    6)
* error, option to continue script on; Command: Shell Emulation.
                                                             (line   33)
* errors, handling of; Command:          Errors.             (line    6)
* ERRRETURN; Program:                    Scripts and Functions.
                                                             (line   89)
* ERR_EXIT; Program:                     Scripts and Functions.
                                                             (line   55)
* ERR_RETURN; Program:                   Scripts and Functions.
                                                             (line   89)
* escape sequences, terminal, for highlighting; Command: Character Highlighting.
                                                             (line   78)
* EUID; Variable:                        Parameters Set by the Shell.
                                                             (line  116)
* eval; Function:                        Shell Builtin Commands.
                                                             (line  723)
* EVALLINENO; Program:                   Scripts and Functions.
                                                             (line  114)
* evaluating arguments as commands; Command: Shell Builtin Commands.
                                                             (line  723)
* evaluation, arithmetic; Command:       Arithmetic Evaluation.
                                                             (line    6)
* EVAL_LINENO; Program:                  Scripts and Functions.
                                                             (line  114)
* event designators, history; Command:   Event Designators.  (line    6)
* exact, compstate; Variable:            Completion Special Parameters.
                                                             (line  153)
* exact_string, compstate; Variable:     Completion Special Parameters.
                                                             (line  162)
* example; Function:                     The zsh/example Module.
                                                             (line    8)
* exchange-point-and-mark; Type:         Miscellaneous.      (line   96)
* exec; Function:                        Precommand Modifiers.
                                                             (line   31)
* exec; Function <1>:                    Shell Builtin Commands.
                                                             (line  731)
* EXEC; Program:                         Scripts and Functions.
                                                             (line  127)
* executables, hashing; Command:         Input/Output.       (line   96)
* execute-as-is, MIME style; Keystroke:  MIME Functions.     (line   93)
* execute-last-named-cmd; Type:          Miscellaneous.      (line  136)
* execute-named-cmd; Type:               Miscellaneous.      (line  104)
* execute-never, MIME style; Keystroke:  MIME Functions.     (line  106)
* execution, of commands; Command:       Command Execution.  (line    6)
* execution, timed; Command:             The zsh/sched Module.
                                                             (line    9)
* exit status from pipeline; Command:    Scripts and Functions.
                                                             (line  218)
* exit status, printing; Command:        Input/Output.       (line  139)
* exit status, trapping; Command:        Scripts and Functions.
                                                             (line   55)
* exit; Function:                        Shell Builtin Commands.
                                                             (line  751)
* exiting loops; Command:                Shell Builtin Commands.
                                                             (line  213)
* exiting shell, and asynchronous jobs; Command: Signals.    (line   12)
* exiting, checking jobs when; Command:  Job Control.        (line   22)
* exiting, checking running jobs when; Command: Job Control. (line   35)
* expand, completion style; Keystroke:   Standard Styles.    (line  277)
* expand-absolute-path; Type:            Widgets.            (line  491)
* expand-cmd-path; Type:                 Completion<3>.      (line   20)
* expand-history; Type:                  Completion<3>.      (line   33)
* expand-or-complete-prefix; Type:       Completion<3>.      (line   29)
* expand-or-complete; Type:              Completion<3>.      (line   24)
* expand-word; Type:                     Completion<3>.      (line   37)
* expanding parameters; Command:         Shell Builtin Commands.
                                                             (line   65)
* expansion style, sh; Command:          Shell Emulation.    (line  270)
* expansion, arithmetic; Command:        Arithmetic Expansion.
                                                             (line    6)
* expansion, brace, disabling; Command:  Expansion and Globbing.
                                                             (line  124)
* expansion, brace, extending; Command:  Expansion and Globbing.
                                                             (line   18)
* expansion, brace; Command:             Brace Expansion.    (line    6)
* expansion, filename; Command:          Filename Expansion. (line    6)
* expansion, history; Command:           History Expansion.  (line    6)
* expansion, parameter; Command:         Parameter Expansion.
                                                             (line    6)
* expansion, prompt; Command:            Expansion of Prompt Sequences.
                                                             (line    6)
* expansion; Command:                    Description.        (line    6)
* expansions, completion tag; Keystroke: Standard Tags.      (line  115)
* expl, use of; Variable:                Utility Functions.  (line  529)
* expl, use of; Variable <1>:            Utility Functions.  (line  990)
* export, automatic; Command:            Initialisation.     (line    6)
* export; Command:                       Description<2>.     (line   24)
* export; Function:                      Shell Builtin Commands.
                                                             (line  764)
* exporting, and local parameters; Command: Initialisation.  (line   26)
* expressions, conditional; Command:     Conditional Expressions.
                                                             (line    6)
* extended attributes, xattr, getting from files; Command: The zsh/attr Module.
                                                             (line   10)
* extended attributes, xattr, listing; Command: The zsh/attr Module.
                                                             (line   26)
* extended attributes, xattr, removing, deleting; Command: The zsh/attr Module.
                                                             (line   21)
* extended attributes, xattr, setting on files; Command: The zsh/attr Module.
                                                             (line   16)
* EXTENDEDGLOB; Program:                 Expansion and Globbing.
                                                             (line   63)
* EXTENDEDHISTORY; Program:              History.            (line   21)
* EXTENDED_GLOB, enable; Program:        Parameter Expansion Flags.
                                                             (line  610)
* EXTENDED_GLOB; Program:                Expansion and Globbing.
                                                             (line   63)
* EXTENDED_HISTORY; Program:             History.            (line   21)
* extensions, completion tag; Keystroke: Standard Tags.      (line  121)
* extra-verbose, completion style; Keystroke: Standard Styles.
                                                             (line  292)
* fake, completion style; Keystroke:     Standard Styles.    (line  302)
* fake-always, completion style; Keystroke: Standard Styles. (line  316)
* fake-files, completion style; Keystroke: Standard Styles.  (line  341)
* fake-parameters, completion style; Keystroke: Standard Styles.
                                                             (line  359)
* false; Function:                       Shell Builtin Commands.
                                                             (line  771)
* fc, use of; Function:                  Overview.           (line   55)
* fc; Function:                          Shell Builtin Commands.
                                                             (line  775)
* FCEDIT; Variable:                      Parameters Used by the Shell.
                                                             (line   90)
* fg, output in POSIX format; Command:   Job Control.        (line   60)
* fg; Function:                          Shell Builtin Commands.
                                                             (line  916)
* field splitting, sh style, parameter; Command: Parameter Expansion.
                                                             (line  352)
* field splitting, sh style; Command:    Shell Emulation.    (line  289)
* fignore; Variable:                     Parameters Used by the Shell.
                                                             (line   96)
* FIGNORE; Variable:                     Parameters Used by the Shell.
                                                             (line   96)
* file clobbering, allowing; Command:    Input/Output.       (line   10)
* file clobbering, of empty files; Command: Input/Output.    (line   19)
* file clobbering, POSIX compatibility; Command: Shell Emulation.
                                                             (line    6)
* file descriptors, waiting for; Command: The zsh/zselect Module.
                                                             (line    8)
* file descriptors; Command:             Redirection.        (line    6)
* file, history; Command:                Shell Builtin Commands.
                                                             (line  906)
* file-descriptors, completion tag; Keystroke: Standard Tags.
                                                             (line  125)
* file-list, completion style; Keystroke: Standard Styles.   (line  370)
* file-path, MIME style; Keystroke:      MIME Functions.     (line  128)
* file-patterns, completion style; Keystroke: Standard Styles.
                                                             (line  406)
* file-sort, completion style; Keystroke: Standard Styles.   (line  473)
* file-split-chars, completion style; Keystroke: Standard Styles.
                                                             (line  489)
* filename expansion, =; Command:        Expansion and Globbing.
                                                             (line   58)
* filename expansion, notes; Command:    Notes.              (line    6)
* filename expansion; Command:           Filename Expansion. (line    6)
* filename generation, bad pattern; Command: Expansion and Globbing.
                                                             (line    6)
* filename generation; Command:          Filename Generation.
                                                             (line    6)
* files, completion tag; Keystroke:      Standard Tags.      (line  129)
* files, examining; Command:             The zsh/stat Module.
                                                             (line    9)
* files, global startup, inhibiting; Command: Initialisation.
                                                             (line   26)
* files, listing; Command:               The zsh/stat Module.
                                                             (line    9)
* files, manipulating; Command:          The zsh/files Module.
                                                             (line    6)
* files, marking type of; Command:       Completion<2>.      (line  133)
* files, shutdown; Command:              Startup/Shutdown Files.
                                                             (line    6)
* files, startup; Command:               Startup/Shutdown Files.
                                                             (line    6)
* files, transferring; Command:          The zsh/zftp Module.
                                                             (line    8)
* filter, completion style; Keystroke:   Standard Styles.    (line  499)
* find-file-in-path, MIME style; Keystroke: MIME Functions.  (line  140)
* flags, MIME style; Keystroke:          MIME Functions.     (line  152)
* flags, parameter expansion; Command:   Parameter Expansion Flags.
                                                             (line    6)
* flags, shell; Command:                 Invocation<2>.      (line    6)
* float, use of; Function:               Arithmetic Evaluation.
                                                             (line  320)
* float; Function:                       Shell Builtin Commands.
                                                             (line  923)
* floating point parameters; Command:    Arithmetic Evaluation.
                                                             (line  320)
* floating point, forcing use of; Command: Expansion and Globbing.
                                                             (line   69)
* flow control; Command:                 Input/Output.       (line   60)
* FLOWCONTROL; Program:                  Input/Output.       (line   60)
* FLOW_CONTROL; Program:                 Input/Output.       (line   60)
* fned; Function:                        Descriptions.       (line   73)
* fonts, completion tag; Keystroke:      Standard Tags.      (line  134)
* for loops; Command:                    Complex Commands.   (line   16)
* for; Function:                         Complex Commands.   (line   16)
* force-list, completion style; Keystroke: Standard Styles.  (line  510)
* FORCEFLOAT; Program:                   Expansion and Globbing.
                                                             (line   69)
* FORCE_FLOAT; Program:                  Expansion and Globbing.
                                                             (line   69)
* forcing use of floating point; Command: Expansion and Globbing.
                                                             (line   69)
* foreach; Function:                     Alternate Forms For Complex Commands.
                                                             (line   56)
* format, completion style; Keystroke:   Standard Styles.    (line  526)
* formats; Keystroke:                    Configuration<4>.   (line   76)
* forward-char; Type:                    Movement.           (line   75)
* forward-word-match; Type:              Widgets.            (line   28)
* forward-word; Type:                    Movement.           (line  111)
* fpath, searching; Variable:            Shell Builtin Commands.
                                                             (line  122)
* fpath, use of; Variable:               Autoloading Functions.
                                                             (line    6)
* fpath, with zcompile; Variable:        Shell Builtin Commands.
                                                             (line 2944)
* fpath; Variable:                       Parameters Used by the Shell.
                                                             (line  103)
* FPATH; Variable:                       Parameters Used by the Shell.
                                                             (line  103)
* fstypes, completion tag; Keystroke:    Standard Tags.      (line  138)
* FTP sites for zsh; Command:            Availability.       (line    8)
* FTP, functions for using shell as client; Command: Zftp Function System.
                                                             (line    6)
* FTP, starting a session; Command:      Subcommands.        (line    6)
* FTP; Command:                          The zsh/zftp Module.
                                                             (line    8)
* funcfiletrace; Variable:               The zsh/parameter Module.
                                                             (line  223)
* FUNCNEST; Variable:                    Parameters Set by the Shell.
                                                             (line  137)
* funcsourcetrace; Variable:             The zsh/parameter Module.
                                                             (line  234)
* funcstack; Variable:                   The zsh/parameter Module.
                                                             (line  253)
* function return, on error; Command:    Scripts and Functions.
                                                             (line   89)
* function, scope of break and continue; Command: Scripts and Functions.
                                                             (line  142)
* function, use of; Function:            Functions.          (line    6)
* function; Function:                    Complex Commands.   (line  181)
* FUNCTIONARGZERO; Program:              Scripts and Functions.
                                                             (line  134)
* functions, anonymous; Command:         Anonymous Functions.
                                                             (line    6)
* functions, autoloading; Command:       Autoloading Functions.
                                                             (line    6)
* functions, autoloading; Command <1>:   Shell Builtin Commands.
                                                             (line  120)
* functions, completion tag; Keystroke:  Standard Tags.      (line  142)
* functions, defining mathematical; Command: Shell Builtin Commands.
                                                             (line  964)
* functions, defining with expanded aliases; Command: Scripts and Functions.
                                                             (line    6)
* functions, hook; Function:             Hook Functions.     (line    6)
* functions, math, use of; Command:      Arithmetic Evaluation.
                                                             (line  282)
* functions, mathematical; Command:      The zsh/mathfunc Module.
                                                             (line    6)
* functions, profiling; Command:         The zsh/zprof Module.
                                                             (line    6)
* functions, recompiling; Command:       Recompiling Functions.
                                                             (line    6)
* functions, removing; Command:          Shell Builtin Commands.
                                                             (line 2742)
* functions, returning from; Command:    Shell Builtin Commands.
                                                             (line 1849)
* functions, use of; Function:           Functions.          (line   56)
* functions; Command:                    Functions.          (line    6)
* functions; Function:                   Shell Builtin Commands.
                                                             (line  928)
* functions; Variable:                   The zsh/parameter Module.
                                                             (line   29)
* functions_source; Variable:            The zsh/parameter Module.
                                                             (line   41)
* FUNCTION_ARGZERO; Program:             Scripts and Functions.
                                                             (line  134)
* functrace; Variable:                   The zsh/parameter Module.
                                                             (line  268)
* gain-privileges, completion style; Keystroke: Standard Styles.
                                                             (line  558)
* galiases; Variable:                    The zsh/parameter Module.
                                                             (line  102)
* get-bookmarks; Keystroke:              Configuration<4>.   (line  288)
* get-line; Type:                        Miscellaneous.      (line  143)
* get-mq; Keystroke:                     Configuration<4>.   (line  282)
* get-revision; Keystroke:               Configuration<4>.   (line  273)
* get-unapplied; Keystroke:              Configuration<4>.   (line  329)
* getcap; Function:                      The zsh/cap Module. (line   16)
* getln; Function:                       Shell Builtin Commands.
                                                             (line 1055)
* getopts; Function:                     Shell Builtin Commands.
                                                             (line 1060)
* GID; Variable:                         Parameters Set by the Shell.
                                                             (line  147)
* glob flags; Command:                   Globbing Flags.     (line    6)
* glob operators; Command:               Glob Operators.     (line    6)
* glob, completion style; Keystroke:     Standard Styles.    (line  568)
* GLOB; Program:                         Expansion and Globbing.
                                                             (line   76)
* global, completion style; Keystroke:   Standard Styles.    (line  575)
* GLOBALEXPORT; Program:                 Initialisation.     (line   10)
* GLOBALRCS; Program:                    Initialisation.     (line   26)
* GLOBAL_EXPORT; Program:                Initialisation.     (line   10)
* GLOBAL_RCS, use of; Program:           Startup/Shutdown Files.
                                                             (line    6)
* GLOBAL_RCS; Program:                   Initialisation.     (line   26)
* GLOBASSIGN; Program:                   Expansion and Globbing.
                                                             (line   81)
* globbed-files, completion tag; Keystroke: Standard Tags.   (line  147)
* globbing flags; Command:               Globbing Flags.     (line    6)
* globbing modifiers; Command:           Modifiers.          (line    6)
* globbing qualifiers, enable; Command:  Expansion and Globbing.
                                                             (line   12)
* globbing style, sh; Command:           Expansion and Globbing.
                                                             (line  232)
* globbing, ** special; Command:         Expansion and Globbing.
                                                             (line   99)
* globbing, bad pattern; Command:        Expansion and Globbing.
                                                             (line    6)
* globbing, enabling; Command:           Expansion and Globbing.
                                                             (line   76)
* globbing, extended; Command:           Expansion and Globbing.
                                                             (line   63)
* globbing, no matches; Command:         Expansion and Globbing.
                                                             (line  200)
* globbing, no matches; Command <1>:     Expansion and Globbing.
                                                             (line  206)
* globbing, null, style, csh; Command:   Expansion and Globbing.
                                                             (line   52)
* globbing, of . files; Command:         Expansion and Globbing.
                                                             (line   94)
* globbing, qualifiers; Command:         Glob Qualifiers.    (line    6)
* globbing, recursive; Command:          Recursive Globbing. (line    6)
* globbing, short forms; Command:        Expansion and Globbing.
                                                             (line   99)
* globbing, sorting numerically; Command: Expansion and Globbing.
                                                             (line  212)
* globbing; Command:                     Description.        (line   42)
* GLOBCOMPLETE; Program:                 Completion<2>.      (line   82)
* GLOBDOTS; Program:                     Expansion and Globbing.
                                                             (line   94)
* GLOBSTARSHORT; Program:                Expansion and Globbing.
                                                             (line   99)
* GLOBSUBST; Program:                    Expansion and Globbing.
                                                             (line  109)
* GLOB_ASSIGN; Program:                  Expansion and Globbing.
                                                             (line   81)
* GLOB_COMPLETE; Program:                Completion<2>.      (line   82)
* GLOB_DOTS; Program:                    Expansion and Globbing.
                                                             (line   94)
* GLOB_STAR_SHORT; Program:              Expansion and Globbing.
                                                             (line   99)
* GLOB_SUBST, toggle; Program:           Parameter Expansion.
                                                             (line  369)
* GLOB_SUBST; Program:                   Expansion and Globbing.
                                                             (line  109)
* gosmacs-transpose-chars; Type:         Modifying Text.     (line  120)
* grammar, shell; Command:               Shell Grammar.      (line    6)
* group-name, completion style; Keystroke: Standard Styles.  (line  580)
* group-order, completion style; Keystroke: Standard Styles. (line  610)
* groups, completion style; Keystroke:   Standard Styles.    (line  625)
* groups, completion tag; Keystroke:     Standard Tags.      (line  151)
* handle-nonexistent, MIME style; Keystroke: MIME Functions. (line  158)
* handler, MIME style; Keystroke:        MIME Functions.     (line  171)
* hash; Command:                         Description<2>.     (line   16)
* hash; Function:                        Shell Builtin Commands.
                                                             (line 1106)
* HASHALL; Program:                      Option Aliases.     (line   18)
* HASHCMDS; Program:                     Input/Output.       (line   81)
* HASHDIRS; Program:                     Input/Output.       (line   90)
* HASHEXECUTABLESONLY; Program:          Input/Output.       (line   96)
* hashing, of commands; Command:         Input/Output.       (line   81)
* hashing, of directories; Command:      Input/Output.       (line   90)
* hashing, of executables; Command:      Input/Output.       (line   96)
* HASHLISTALL; Program:                  Completion<2>.      (line   98)
* HASH_ALL; Program:                     Option Aliases.     (line   18)
* HASH_CMDS; Program:                    Input/Output.       (line   81)
* HASH_DIRS; Program:                    Input/Output.       (line   90)
* HASH_EXECUTABLES_ONLY; Program:        Input/Output.       (line   96)
* HASH_LIST_ALL; Program:                Completion<2>.      (line   98)
* HELPDIR; Variable:                     Accessing On-Line Help.
                                                             (line   33)
* helpfiles utility; Command:            Accessing On-Line Help.
                                                             (line    6)
* hexadecimal, output in C format; Command: Scripts and Functions.
                                                             (line   32)
* hgrevformat; Keystroke:                Configuration<4>.   (line  101)
* hidden, completion style; Keystroke:   Standard Styles.    (line  630)
* highlighting, region; Command:         Character Highlighting.
                                                             (line   19)
* highlighting, special characters; Command: Character Highlighting.
                                                             (line   41)
* HISTALLOWCLOBBER; Program:             History.            (line   29)
* HISTAPPEND; Program:                   Option Aliases.     (line   22)
* HISTBEEP; Program:                     History.            (line   34)
* histchars, use of; Variable:           Comments.           (line    6)
* histchars, use of; Variable <1>:       Overview.           (line    6)
* histchars; Variable:                   Parameters Used by the Shell.
                                                             (line  111)
* HISTCHARS; Variable:                   Parameters Used by the Shell.
                                                             (line  123)
* HISTCMD; Variable:                     Parameters Set by the Shell.
                                                             (line  158)
* histed; Function:                      Descriptions.       (line   79)
* HISTEXPAND; Program:                   Option Aliases.     (line   26)
* HISTEXPIREDUPSFIRST; Program:          History.            (line   39)
* HISTFCNTLLOCK; Program:                History.            (line   50)
* HISTFILE; Variable:                    Parameters Used by the Shell.
                                                             (line  127)
* HISTFINDNODUPS; Program:               History.            (line   59)
* HISTIGNOREALLDUPS; Program:            History.            (line   65)
* HISTIGNOREDUPS; Program:               History.            (line   71)
* HISTIGNORESPACE; Program:              History.            (line   76)
* HISTLEXWORDS; Program:                 History.            (line   87)
* HISTNO; Variable:                      User-Defined Widgets.
                                                             (line   88)
* HISTNOFUNCTIONS; Program:              History.            (line   99)
* HISTNOSTORE; Program:                  History.            (line  106)
* history beeping; Command:              History.            (line   34)
* history event designators; Command:    Event Designators.  (line    6)
* history expansion; Command:            History Expansion.  (line    6)
* history modifiers; Command:            Modifiers.          (line    6)
* history style, csh; Command:           Shell Emulation.    (line   43)
* history word designators; Command:     Word Designators.   (line    6)
* history, appending to a file; Command: History.            (line    6)
* history, editing; Command:             Shell Builtin Commands.
                                                             (line  775)
* history, enable substitution; Command: History.            (line   16)
* history, expiring duplicates; Command: History.            (line   39)
* history, file; Command:                Shell Builtin Commands.
                                                             (line  906)
* history, hook when line is saved; Command: Hook Functions. (line   55)
* history, ignoring all duplicates; Command: History.        (line   65)
* history, ignoring duplicates in search; Command: History.  (line   59)
* history, ignoring duplicates; Command: History.            (line   71)
* history, ignoring spaces; Command:     History.            (line   76)
* history, incremental appending to a file with time; Command: History.
                                                             (line  154)
* history, incremental appending to a file; Command: History.
                                                             (line  145)
* history, sharing; Command:             History.            (line  168)
* history, stack; Command:               Shell Builtin Commands.
                                                             (line  875)
* history, timestamping; Command:        History.            (line   21)
* history, verifying substitution; Command: History.         (line  139)
* history-beginning-search-backward-end; Type: Widgets.      (line  498)
* history-beginning-search-backward; Type: History Control.  (line   45)
* history-beginning-search-forward-end; Type: Widgets.       (line  498)
* history-beginning-search-forward; Type: History Control.   (line  350)
* history-beginning-search-menu; Type:   Widgets.            (line  519)
* history-incremental-pattern-search-backward; Type: History Control.
                                                             (line  199)
* history-incremental-pattern-search-forward; Type: History Control.
                                                             (line  199)
* history-incremental-search-backward; Type: History Control.
                                                             (line   71)
* history-incremental-search-forward; Type: History Control. (line  190)
* history-pattern-search-backward; Type: Widgets.            (line  543)
* history-pattern-search-forward; Type:  Widgets.            (line  543)
* history-pattern-search; Type:          Widgets.            (line  543)
* history-search-backward; Type:         History Control.    (line  219)
* history-search-forward; Type:          History Control.    (line  252)
* history-words, completion tag; Keystroke: Standard Tags.   (line  155)
* history; Command:                      History Expansion.  (line    6)
* history; Function:                     Shell Builtin Commands.
                                                             (line 1159)
* history; Variable:                     The zsh/parameter Module.
                                                             (line  151)
* historywords; Variable:                The zsh/parameter Module.
                                                             (line  159)
* HISTORY_IGNORE; Variable:              Parameters Used by the Shell.
                                                             (line  132)
* HISTREDUCEBLANKS; Program:             History.            (line  113)
* HISTSAVEBYCOPY; Program:               History.            (line  118)
* HISTSAVENODUPS; Program:               History.            (line  134)
* HISTSIZE, use of; Variable:            History Expansion.  (line   10)
* HISTSIZE; Variable:                    Parameters Used by the Shell.
                                                             (line  157)
* HISTSUBSTPATTERN; Program:             Expansion and Globbing.
                                                             (line  117)
* HISTVERIFY; Program:                   History.            (line  139)
* HIST_ALLOW_CLOBBER; Program:           History.            (line   29)
* HIST_APPEND; Program:                  Option Aliases.     (line   22)
* HIST_BEEP; Program:                    History.            (line   34)
* HIST_EXPAND; Program:                  Option Aliases.     (line   26)
* HIST_EXPIRE_DUPS_FIRST; Program:       History.            (line   39)
* HIST_FCNTL_LOCK; Program:              History.            (line   50)
* HIST_FIND_NO_DUPS; Program:            History.            (line   59)
* HIST_IGNORE_ALL_DUPS; Program:         History.            (line   65)
* HIST_IGNORE_DUPS; Program:             History.            (line   71)
* HIST_IGNORE_SPACE; Program:            History.            (line   76)
* HIST_LEX_WORDS; Program:               History.            (line   87)
* HIST_NO_FUNCTIONS; Program:            History.            (line   99)
* HIST_NO_STORE; Program:                History.            (line  106)
* HIST_REDUCE_BLANKS; Program:           History.            (line  113)
* HIST_SAVE_BY_COPY; Program:            History.            (line  118)
* HIST_SAVE_NO_DUPS; Program:            History.            (line  134)
* HIST_SUBST_PATTERN; Program:           Expansion and Globbing.
                                                             (line  117)
* HIST_VERIFY; Program:                  History.            (line  139)
* HOME, use of; Variable:                Startup/Shutdown Files.
                                                             (line   36)
* HOME; Variable:                        Parameters Used by the Shell.
                                                             (line  167)
* hook function utility; Command:        Manipulating Hook Functions.
                                                             (line    6)
* hook functions; Function:              Hook Functions.     (line    6)
* hooks; Keystroke:                      Configuration<4>.   (line  308)
* HOST; Variable:                        Parameters Set by the Shell.
                                                             (line  165)
* hosts, completion style; Keystroke:    Standard Styles.    (line  642)
* hosts, completion tag; Keystroke:      Standard Tags.      (line  159)
* hosts-ports, completion style; Keystroke: Standard Styles. (line  647)
* HUP; Program:                          Job Control.        (line   43)
* identifiers, non-portable characters in; Command: Shell Emulation.
                                                             (line  198)
* if construct; Command:                 Complex Commands.   (line    8)
* if; Function:                          Complex Commands.   (line    8)
* IFS, use of; Variable:                 Shell Builtin Commands.
                                                             (line 1701)
* IFS; Variable:                         Parameters Used by the Shell.
                                                             (line  174)
* ignore-line, completion style; Keystroke: Standard Styles. (line  654)
* ignore-parents, completion style; Keystroke: Standard Styles.
                                                             (line  676)
* IGNOREBRACES; Program:                 Expansion and Globbing.
                                                             (line  124)
* IGNORECLOSEBRACES; Program:            Expansion and Globbing.
                                                             (line  129)
* ignored, compstate; Variable:          Completion Special Parameters.
                                                             (line  167)
* ignored-patterns, completion style; Keystroke: Standard Styles.
                                                             (line  713)
* IGNOREEOF; Program:                    Input/Output.       (line   66)
* IGNORE_BRACES; Program:                Expansion and Globbing.
                                                             (line  124)
* IGNORE_CLOSE_BRACES; Program:          Expansion and Globbing.
                                                             (line  129)
* IGNORE_EOF; Program:                   Input/Output.       (line   66)
* INCAPPENDHISTORY; Program:             History.            (line  145)
* INCAPPENDHISTORYTIME; Program:         History.            (line  154)
* incarg, use of; Variable:              Widgets.            (line  560)
* incarg; Type:                          Widgets.            (line  560)
* incremental-complete-word; Type:       Widgets.            (line  594)
* INC_APPEND_HISTORY; Program:           History.            (line  145)
* INC_APPEND_HISTORY_TIME; Program:      History.            (line  154)
* indexes, completion tag; Keystroke:    Standard Tags.      (line  163)
* infer-next-history; Type:              History Control.    (line  269)
* input, tracing; Command:               Scripts and Functions.
                                                             (line  252)
* insert, completion style; Keystroke:   Standard Styles.    (line  725)
* insert, compstate; Variable:           Completion Special Parameters.
                                                             (line  173)
* insert-composed-char; Type:            Widgets.            (line  609)
* insert-files; Type:                    Widgets.            (line 1079)
* insert-ids, completion style; Keystroke: Standard Styles.  (line  731)
* insert-last-word; Type:                History Control.    (line  274)
* insert-sections, completion style; Keystroke: Standard Styles.
                                                             (line  748)
* insert-tab, completion style; Keystroke: Standard Styles.  (line  770)
* insert-tab, completion style; Keystroke <1>: Styles<3>.    (line    6)
* insert-unambiguous, completion style; Keystroke: Standard Styles.
                                                             (line  791)
* insert-unicode-char; Type:             Widgets.            (line 1087)
* insert_positions, compstate; Variable: Completion Special Parameters.
                                                             (line  211)
* integer parameters; Command:           Arithmetic Evaluation.
                                                             (line  316)
* integer, use of; Function:             Arithmetic Evaluation.
                                                             (line  316)
* integer; Function:                     Shell Builtin Commands.
                                                             (line 1163)
* INTERACTIVE, use of; Program:          Shell State<2>.     (line   65)
* INTERACTIVE; Program:                  Shell State<2>.     (line    6)
* INTERACTIVECOMMENTS; Program:          Input/Output.       (line   77)
* INTERACTIVE_COMMENTS, use of; Program: Comments.           (line    6)
* INTERACTIVE_COMMENTS; Program:         Input/Output.       (line   77)
* interfaces, completion tag; Keystroke: Standard Tags.      (line  167)
* introduction; Command:                 Introduction.       (line    6)
* invocation; Command:                   Invocation.         (line    6)
* invoking widgets; Command:             Zle Builtins.       (line  296)
* IPREFIX; Variable:                     Completion Special Parameters.
                                                             (line   27)
* is-at-least; Function:                 Descriptions.       (line   85)
* ISEARCHMATCH_ACTIVE; Variable:         User-Defined Widgets.
                                                             (line   98)
* ISEARCHMATCH_END; Variable:            User-Defined Widgets.
                                                             (line   98)
* ISEARCHMATCH_START; Variable:          User-Defined Widgets.
                                                             (line   98)
* ISUFFIX; Variable:                     Completion Special Parameters.
                                                             (line   42)
* job control, allowing; Command:        Job Control.        (line   51)
* job control, in subshell; Command:     Job Control.        (line   60)
* jobdirs; Variable:                     The zsh/parameter Module.
                                                             (line  164)
* jobs, asynchronous, and exiting shell; Command: Signals.   (line   12)
* jobs, background priority; Command:    Job Control.        (line   17)
* jobs, background, I/O; Command:        Jobs.               (line   62)
* jobs, backgrounding; Command:          Shell Builtin Commands.
                                                             (line  202)
* jobs, completion tag; Keystroke:       Standard Tags.      (line  171)
* jobs, continuing automatically; Command: Job Control.      (line    6)
* jobs, disowning; Command:              Jobs.               (line  120)
* jobs, disowning; Command <1>:          Shell Builtin Commands.
                                                             (line  488)
* jobs, foregrounding; Command:          Shell Builtin Commands.
                                                             (line  916)
* jobs, HUP; Command:                    Job Control.        (line   43)
* jobs, killing; Command:                Shell Builtin Commands.
                                                             (line 1204)
* jobs, list format; Command:            Job Control.        (line   47)
* jobs, output in subshell; Command:     Job Control.        (line   60)
* jobs, referring to; Command:           Jobs.               (line   72)
* jobs, resuming automatically; Command: Job Control.        (line   12)
* jobs, resuming; Command:               Shell Builtin Commands.
                                                             (line  916)
* jobs, waiting for; Command:            Shell Builtin Commands.
                                                             (line 2810)
* jobs; Command:                         Jobs.               (line    6)
* jobs; Function:                        Shell Builtin Commands.
                                                             (line 1169)
* jobstates; Variable:                   The zsh/parameter Module.
                                                             (line  189)
* jobtexts; Variable:                    The zsh/parameter Module.
                                                             (line  178)
* keep-prefix, completion style; Keystroke: Standard Styles. (line  809)
* key bindings; Command:                 Keymaps.            (line    6)
* keyboard definition; Command:          Keyboard Definition.
                                                             (line    6)
* KEYBOARD_HACK; Variable:               Parameters Used by the Shell.
                                                             (line  193)
* KEYMAP; Variable:                      User-Defined Widgets.
                                                             (line  112)
* keymaps, completion tag; Keystroke:    Standard Tags.      (line  175)
* keymaps; Command:                      Keymaps.            (line    6)
* keymaps; Command <1>:                  Zle Builtins.       (line   12)
* keymaps; Variable:                     The zsh/zleparameter Module.
                                                             (line   10)
* keys, binding; Command:                Zle Builtins.       (line   12)
* keys, rebinding; Command:              Zle Builtins.       (line   12)
* KEYS; Variable:                        User-Defined Widgets.
                                                             (line  116)
* keysyms, completion tag; Keystroke:    Standard Tags.      (line  179)
* KEYS_QUEUED_COUNT; Variable:           User-Defined Widgets.
                                                             (line  121)
* KEYTIMEOUT; Variable:                  Parameters Used by the Shell.
                                                             (line  207)
* kill-buffer; Type:                     Modifying Text.     (line  158)
* kill-line; Type:                       Modifying Text.     (line  141)
* kill-region; Type:                     Modifying Text.     (line  154)
* kill-whole-line; Type:                 Modifying Text.     (line  162)
* kill-word-match; Type:                 Widgets.            (line   28)
* kill-word; Type:                       Modifying Text.     (line  116)
* kill; Function:                        Shell Builtin Commands.
                                                             (line 1204)
* killing jobs; Command:                 Shell Builtin Commands.
                                                             (line 1204)
* killring; Variable:                    User-Defined Widgets.
                                                             (line  127)
* known-hosts-files; Keystroke:          Standard Styles.    (line  825)
* ksh compatibility; Command:            Compatibility.      (line    6)
* ksh, argument splitting in typeset; Command: Shell Emulation.
                                                             (line   96)
* ksh, array style; Command:             Shell Emulation.    (line   71)
* ksh, compatibility; Command:           Shell Builtin Commands.
                                                             (line  588)
* ksh, editor mode; Command:             Description<3>.     (line   17)
* ksh, null command style; Command:      Parameters Used by the Shell.
                                                             (line  324)
* ksh, option printing style; Command:   Shell Emulation.    (line   90)
* ksh, redirections with no command; Command: Shell Emulation.
                                                             (line  278)
* ksh, single letter options style; Command: Shell Emulation.
                                                             (line  283)
* ksh93; Command:                        The zsh/ksh93 Module.
                                                             (line    6)
* KSHARRAYS; Program:                    Shell Emulation.    (line   71)
* KSHAUTOLOAD; Program:                  Shell Emulation.    (line   80)
* KSHGLOB; Program:                      Expansion and Globbing.
                                                             (line  149)
* KSHOPTIONPRINT; Program:               Shell Emulation.    (line   90)
* KSHTYPESET; Program:                   Shell Emulation.    (line   96)
* KSHZEROSUBSCRIPT; Program:             Shell Emulation.    (line  111)
* KSH_ARRAYS, use of; Program:           Shell Builtin Commands.
                                                             (line 1878)
* KSH_ARRAYS; Program:                   Shell Emulation.    (line   71)
* KSH_AUTOLOAD, use of; Program:         Autoloading Functions.
                                                             (line   65)
* KSH_AUTOLOAD; Program:                 Shell Emulation.    (line   80)
* KSH_GLOB, use of; Program:             ksh-like Glob Operators.
                                                             (line    6)
* KSH_GLOB; Program:                     Expansion and Globbing.
                                                             (line  149)
* KSH_OPTION_PRINT; Program:             Shell Emulation.    (line   90)
* KSH_TYPESET; Program:                  Shell Emulation.    (line   96)
* KSH_ZERO_SUBSCRIPT; Program:           Shell Emulation.    (line  111)
* LANG; Variable:                        Parameters Used by the Shell.
                                                             (line  212)
* langinfo; Variable:                    The zsh/langinfo Module.
                                                             (line    8)
* last-prompt, completion style; Keystroke: Standard Styles. (line  832)
* LASTABORTEDSEARCH; Variable:           User-Defined Widgets.
                                                             (line  142)
* LASTSEARCH; Variable:                  User-Defined Widgets.
                                                             (line  147)
* LASTWIDGET; Variable:                  User-Defined Widgets.
                                                             (line  153)
* last_prompt, compstate; Variable:      Completion Special Parameters.
                                                             (line  219)
* LBUFFER; Variable:                     User-Defined Widgets.
                                                             (line  157)
* LC_ALL; Variable:                      Parameters Used by the Shell.
                                                             (line  217)
* LC_COLLATE; Variable:                  Parameters Used by the Shell.
                                                             (line  222)
* LC_CTYPE; Variable:                    Parameters Used by the Shell.
                                                             (line  228)
* LC_MESSAGES; Variable:                 Parameters Used by the Shell.
                                                             (line  238)
* LC_NUMERIC; Variable:                  Parameters Used by the Shell.
                                                             (line  243)
* LC_TIME; Variable:                     Parameters Used by the Shell.
                                                             (line  250)
* let, use of; Function:                 Arithmetic Evaluation.
                                                             (line    6)
* let; Function:                         Shell Builtin Commands.
                                                             (line 1239)
* libraries, completion tag; Keystroke:  Standard Tags.      (line  183)
* limit; Function:                       Shell Builtin Commands.
                                                             (line 1246)
* limits, completion tag; Keystroke:     Standard Tags.      (line  187)
* limits, resource; Command:             Shell Builtin Commands.
                                                             (line 1246)
* limits, resource; Command <1>:         Shell Builtin Commands.
                                                             (line 2589)
* limits, resource; Command <2>:         Shell Builtin Commands.
                                                             (line 2760)
* line editor; Command:                  Zsh Line Editor.    (line    6)
* line number, in evaluated expression; Command: Scripts and Functions.
                                                             (line  114)
* line, reading; Command:                Shell Builtin Commands.
                                                             (line 1055)
* line, use of; Variable:                Utility Functions.  (line  463)
* LINENO; Variable:                      Parameters Set by the Shell.
                                                             (line  169)
* LINES, use of; Variable:               Description<3>.     (line   20)
* LINES; Variable:                       Parameters Used by the Shell.
                                                             (line  255)
* links, symbolic; Command:              Changing Directories.
                                                             (line   53)
* list, completion style; Keystroke:     Standard Styles.    (line  843)
* list, compstate; Variable:             Completion Special Parameters.
                                                             (line  227)
* list, widget style; Keystroke:         Styles<2>.          (line   70)
* list-choices; Type:                    Completion<3>.      (line   41)
* list-colors, completion style; Keystroke: Standard Styles. (line  852)
* list-dirs-first, completion style; Keystroke: Standard Styles.
                                                             (line  880)
* list-expand; Type:                     Completion<3>.      (line   45)
* list-grouped, completion style; Keystroke: Standard Styles.
                                                             (line  887)
* list-packed, completion style; Keystroke: Standard Styles. (line  896)
* list-prompt, completion style; Keystroke: Standard Styles. (line  903)
* list-rows-first, completion style; Keystroke: Standard Styles.
                                                             (line  931)
* list-separator, completion style; Keystroke: Standard Styles.
                                                             (line  937)
* list-suffixes, completion style; Keystroke: Standard Styles.
                                                             (line  943)
* list; Command:                         Simple Commands & Pipelines.
                                                             (line   61)
* LISTAMBIGUOUS; Program:                Completion<2>.      (line  105)
* LISTBEEP; Program:                     Completion<2>.      (line  114)
* LISTMAX; Variable:                     Parameters Used by the Shell.
                                                             (line  260)
* LISTPACKED; Program:                   Completion<2>.      (line  122)
* LISTROWSFIRST; Program:                Completion<2>.      (line  127)
* LISTTYPES; Program:                    Completion<2>.      (line  133)
* LIST_AMBIGUOUS; Program:               Completion<2>.      (line  105)
* LIST_BEEP; Program:                    Completion<2>.      (line  114)
* list_lines, compstate; Variable:       Completion Special Parameters.
                                                             (line  254)
* list_max, compstate; Variable:         Completion Special Parameters.
                                                             (line  262)
* LIST_PACKED; Program:                  Completion<2>.      (line  122)
* LIST_ROWS_FIRST; Program:              Completion<2>.      (line  127)
* LIST_TYPES; Program:                   Completion<2>.      (line  133)
* ln; Function:                          The zsh/files Module.
                                                             (line   99)
* loading modules; Command:              Shell Builtin Commands.
                                                             (line 3066)
* local keymaps; Command:                Local Keymaps.      (line    6)
* local parameters; Command:             Positional Parameters.
                                                             (line   28)
* local, completion style; Keystroke:    Standard Styles.    (line  951)
* local-directories, completion tag; Keystroke: Standard Tags.
                                                             (line  191)
* local; Function:                       Shell Builtin Commands.
                                                             (line 1422)
* LOCALLOOPS; Program:                   Scripts and Functions.
                                                             (line  142)
* LOCALOPTIONS; Program:                 Scripts and Functions.
                                                             (line  151)
* LOCALPATTERNS; Program:                Scripts and Functions.
                                                             (line  163)
* LOCALTRAPS; Program:                   Scripts and Functions.
                                                             (line  172)
* LOCAL_LOOPS; Program:                  Scripts and Functions.
                                                             (line  142)
* LOCAL_OPTIONS; Program:                Scripts and Functions.
                                                             (line  151)
* LOCAL_PATTERNS; Program:               Scripts and Functions.
                                                             (line  163)
* LOCAL_TRAPS; Program:                  Scripts and Functions.
                                                             (line  172)
* log; Function:                         The zsh/watch Module.
                                                             (line  148)
* LOG; Program:                          Option Aliases.     (line   30)
* LOGCHECK; Variable:                    The zsh/watch Module.
                                                             (line    9)
* logging out, checking jobs when; Command: Job Control.     (line   22)
* logging out, checking running jobs when; Command: Job Control.
                                                             (line   35)
* LOGIN; Program:                        Shell State<2>.     (line   16)
* LOGNAME; Variable:                     Parameters Set by the Shell.
                                                             (line  178)
* logout; Function:                      Shell Builtin Commands.
                                                             (line 1429)
* long option; Command:                  Invocation<2>.      (line   66)
* LONGLISTJOBS; Program:                 Job Control.        (line   47)
* LONG_LIST_JOBS; Program:               Job Control.        (line   47)
* loop style, csh; Command:              Shell Emulation.    (line   51)
* loops, continuing; Command:            Shell Builtin Commands.
                                                             (line  347)
* loops, exiting; Command:               Shell Builtin Commands.
                                                             (line  213)
* loops, for; Command:                   Complex Commands.   (line   16)
* loops, repeat; Command:                Complex Commands.   (line   57)
* loops, until; Command:                 Complex Commands.   (line   52)
* loops, while; Command:                 Complex Commands.   (line   47)
* MACHTYPE; Variable:                    Parameters Set by the Shell.
                                                             (line  187)
* magic-space; Type:                     Completion<3>.      (line   49)
* MAGICEQUALSUBST; Program:              Expansion and Globbing.
                                                             (line  155)
* MAGIC_EQUAL_SUBST; Program:            Expansion and Globbing.
                                                             (line  155)
* mail, warning of reading; Command:     Input/Output.       (line  105)
* mail-directory, completion style; Keystroke: Standard Styles.
                                                             (line  969)
* MAIL; Variable:                        Parameters Used by the Shell.
                                                             (line  268)
* mailboxes, completion tag; Keystroke:  Standard Tags.      (line  198)
* mailcap, MIME style; Keystroke:        MIME Functions.     (line  183)
* mailcap-prio-flags, MIME style; Keystroke: MIME Functions. (line  224)
* mailcap-priorities, MIME style; Keystroke: MIME Functions. (line  191)
* MAILCHECK; Variable:                   Parameters Used by the Shell.
                                                             (line  273)
* mailing lists; Command:                Mailing Lists.      (line    6)
* mailpath; Variable:                    Parameters Used by the Shell.
                                                             (line  277)
* MAILPATH; Variable:                    Parameters Used by the Shell.
                                                             (line  277)
* MAILWARN; Program:                     Option Aliases.     (line   34)
* MAILWARNING; Program:                  Input/Output.       (line  105)
* MAIL_WARN; Program:                    Option Aliases.     (line   34)
* MAIL_WARNING; Program:                 Input/Output.       (line  105)
* manpath; Variable:                     Parameters Used by the Shell.
                                                             (line  288)
* MANPATH; Variable:                     Parameters Used by the Shell.
                                                             (line  288)
* manuals, completion tag; Keystroke:    Standard Tags.      (line  202)
* mapfile; Variable:                     The zsh/mapfile Module.
                                                             (line    9)
* maps, completion tag; Keystroke:       Standard Tags.      (line  206)
* MARK; Variable:                        User-Defined Widgets.
                                                             (line  164)
* MARKDIRS; Program:                     Expansion and Globbing.
                                                             (line  171)
* marking directories; Command:          Expansion and Globbing.
                                                             (line  171)
* marking file types; Command:           Completion<2>.      (line  133)
* MARK_DIRS; Program:                    Expansion and Globbing.
                                                             (line  171)
* match, widget style; Keystroke:        Styles<2>.          (line   82)
* match-original, completion style; Keystroke: Standard Styles.
                                                             (line  974)
* match-word-context; Type:              Widgets.            (line   28)
* match-words-by-style; Type:            Widgets.            (line   28)
* match; Variable:                       Globbing Flags.     (line   27)
* MATCH; Variable:                       Globbing Flags.     (line  101)
* matcher, completion style; Keystroke:  Standard Styles.    (line  984)
* matcher-list, completion style; Keystroke: Standard Styles.
                                                             (line  996)
* matching, approximate; Command:        Approximate Matching.
                                                             (line    6)
* mathematical functions, use of; Command: Arithmetic Evaluation.
                                                             (line  282)
* mathematical functions; Command:       The zsh/mathfunc Module.
                                                             (line    6)
* max-errors, completion style; Keystroke: Standard Styles.  (line 1061)
* max-exports; Keystroke:                Configuration<4>.   (line  111)
* max-matches-width, completion style; Keystroke: Standard Styles.
                                                             (line 1091)
* max; Function:                         Mathematical Functions.
                                                             (line  242)
* mbegin; Variable:                      Globbing Flags.     (line   27)
* MBEGIN; Variable:                      Globbing Flags.     (line  101)
* mend; Variable:                        Globbing Flags.     (line   27)
* MEND; Variable:                        Globbing Flags.     (line  101)
* menu, completion style; Keystroke:     Standard Styles.    (line 1104)
* menu-complete; Type:                   Completion<3>.      (line   54)
* menu-expand-or-complete; Type:         Completion<3>.      (line   59)
* menu-select; Type:                     Menu Selection.     (line    6)
* MENUCOMPLETE; Program:                 Completion<2>.      (line  138)
* MENUSELECT; Variable:                  Menu Selection.     (line    6)
* MENU_COMPLETE, use of; Program:        Completion<3>.      (line   54)
* MENU_COMPLETE; Program:                Completion<2>.      (line  138)
* messages, completion tag; Keystroke:   Standard Tags.      (line  210)
* mime-types, MIME style; Keystroke:     MIME Functions.     (line  235)
* min; Function:                         Mathematical Functions.
                                                             (line  242)
* mkdir; Function:                       The zsh/files Module.
                                                             (line  128)
* mkshadow; Function:                    Descriptions.       (line  102)
* mode, privileged; Command:             Shell State<2>.     (line   22)
* modifiers, completion tag; Keystroke:  Standard Tags.      (line  214)
* modifiers, precommand; Command:        Precommand Modifiers.
                                                             (line    6)
* modifiers; Command:                    Modifiers.          (line    6)
* modify-current-argument; Type:         Utility Functions<2>.
                                                             (line   34)
* modules, completion tag; Keystroke:    Standard Tags.      (line  218)
* modules, example; Command:             The zsh/example Module.
                                                             (line    8)
* modules, loading; Command:             Shell Builtin Commands.
                                                             (line 3066)
* modules, writing; Command:             The zsh/example Module.
                                                             (line    8)
* modules; Command:                      Zsh Modules.        (line    6)
* modules; Variable:                     The zsh/parameter Module.
                                                             (line  135)
* module_path; Variable:                 Parameters Used by the Shell.
                                                             (line  312)
* MODULE_PATH; Variable:                 Parameters Used by the Shell.
                                                             (line  312)
* MONITOR, use of; Program:              Jobs.               (line    6)
* MONITOR; Program:                      Job Control.        (line   51)
* multibyte characters, in expansion and globbing; Command: Expansion and Globbing.
                                                             (line  176)
* MULTIBYTE; Program:                    Expansion and Globbing.
                                                             (line  176)
* MULTIFUNCDEF; Program:                 Scripts and Functions.
                                                             (line  188)
* MULTIOS, use of; Program:              Multios.            (line    6)
* multios; Command:                      Multios.            (line    6)
* MULTIOS; Program:                      Scripts and Functions.
                                                             (line  202)
* MULTI_FUNC_DEF; Program:               Scripts and Functions.
                                                             (line  188)
* muttrc, completion style; Keystroke:   Standard Styles.    (line 1163)
* mv; Function:                          The zsh/files Module.
                                                             (line  137)
* my-accounts, completion tag; Keystroke: Standard Tags.     (line  222)
* named directories, dynamic, helper function; Command: Details of Directory Handling.
                                                             (line   25)
* named directories, dynamic; Command:   Dynamic Named Directories.
                                                             (line    6)
* named directories, static; Command:    Static Named Directories.
                                                             (line    6)
* named reference; Command:              Shell Builtin Commands.
                                                             (line 2239)
* named references, creating; Command:   Ksh Builtins.       (line    8)
* named references; Command:             Named References.   (line    6)
* named references; Command <1>:         Local Parameters.   (line   37)
* named-directories, completion tag; Keystroke: Standard Tags.
                                                             (line  226)
* nameddirs; Variable:                   The zsh/parameter Module.
                                                             (line  207)
* nameref; Function:                     Ksh Builtins.       (line    8)
* namerefs; Command:                     Named References.   (line    6)
* names, completion tag; Keystroke:      Standard Tags.      (line  230)
* namespace; Command:                    Parameter Expansion.
                                                             (line   35)
* namespace; Command <1>:                Description<2>.     (line   47)
* narrow-to-region-invisible; Type:      Widgets.            (line 1098)
* narrow-to-region; Type:                Widgets.            (line 1098)
* neg-argument; Type:                    Arguments.          (line   15)
* never-background, MIME style; Keystroke: MIME Functions.   (line  243)
* newsgroups, completion tag; Keystroke: Standard Tags.      (line  234)
* nicknames, completion tag; Keystroke:  Standard Tags.      (line  238)
* nmatches, compstate; Variable:         Completion Special Parameters.
                                                             (line  268)
* no clobber, POSIX compatible; Command: Shell Emulation.    (line    6)
* NOALIASES; Program:                    Input/Output.       (line    6)
* NOALIASFUNCDEF; Program:               Scripts and Functions.
                                                             (line    6)
* NOALLEXPORT; Program:                  Initialisation.     (line    6)
* NOALWAYSLASTPROMPT; Program:           Completion<2>.      (line    6)
* NOALWAYSTOEND; Program:                Completion<2>.      (line   12)
* NOAPPENDCREATE; Program:               Shell Emulation.    (line    6)
* NOAPPENDHISTORY; Program:              History.            (line    6)
* NOAUTOCD; Program:                     Changing Directories.
                                                             (line    6)
* NOAUTOCONTINUE; Program:               Job Control.        (line    6)
* NOAUTOLIST; Program:                   Completion<2>.      (line   19)
* NOAUTOMENU; Program:                   Completion<2>.      (line   23)
* NOAUTONAMEDIRS; Program:               Completion<2>.      (line   29)
* NOAUTOPARAMKEYS; Program:              Completion<2>.      (line   37)
* NOAUTOPARAMSLASH; Program:             Completion<2>.      (line   48)
* NOAUTOPUSHD; Program:                  Changing Directories.
                                                             (line   16)
* NOAUTOREMOVESLASH; Program:            Completion<2>.      (line   53)
* NOAUTORESUME; Program:                 Job Control.        (line   12)
* NOBADPATTERN; Program:                 Expansion and Globbing.
                                                             (line    6)
* NOBANGHIST; Program:                   History.            (line   16)
* NOBAREGLOBQUAL; Program:               Expansion and Globbing.
                                                             (line   12)
* NOBASHAUTOLIST; Program:               Completion<2>.      (line   60)
* NOBASHREMATCH; Program:                Shell Emulation.    (line   15)
* NOBEEP; Program:                       Zle.                (line    6)
* NOBGNICE; Program:                     Job Control.        (line   17)
* NOBRACECCL; Program:                   Expansion and Globbing.
                                                             (line   18)
* NOBRACEEXPAND; Program:                Option Aliases.     (line   10)
* NOBSDECHO; Program:                    Shell Emulation.    (line   27)
* NOCASEGLOB; Program:                   Expansion and Globbing.
                                                             (line   24)
* NOCASEMATCH; Program:                  Expansion and Globbing.
                                                             (line   34)
* NOCASEPATHS; Program:                  Expansion and Globbing.
                                                             (line   39)
* NOCBASES; Program:                     Scripts and Functions.
                                                             (line   32)
* NOCDABLEVARS; Program:                 Changing Directories.
                                                             (line   20)
* NOCDSILENT; Program:                   Changing Directories.
                                                             (line   27)
* NOCHASEDOTS; Program:                  Changing Directories.
                                                             (line   37)
* NOCHASELINKS; Program:                 Changing Directories.
                                                             (line   53)
* NOCHECKJOBS; Program:                  Job Control.        (line   22)
* NOCHECKRUNNINGJOBS; Program:           Job Control.        (line   35)
* NOCLOBBER; Program:                    Input/Output.       (line   10)
* NOCLOBBEREMPTY; Program:               Input/Output.       (line   19)
* NOCOMBININGCHARS; Program:             Zle.                (line   10)
* NOCOMPLETEALIASES; Program:            Completion<2>.      (line   70)
* NOCOMPLETEINWORD; Program:             Completion<2>.      (line   76)
* NOCONTINUEONERROR; Program:            Shell Emulation.    (line   33)
* nocorrect; Function:                   Precommand Modifiers.
                                                             (line   51)
* NOCORRECT; Program:                    Input/Output.       (line   31)
* NOCORRECTALL; Program:                 Input/Output.       (line   44)
* NOCPRECEDENCES; Program:               Scripts and Functions.
                                                             (line   43)
* NOCSHJUNKIEHISTORY; Program:           Shell Emulation.    (line   43)
* NOCSHJUNKIELOOPS; Program:             Shell Emulation.    (line   51)
* NOCSHJUNKIEQUOTES; Program:            Shell Emulation.    (line   56)
* NOCSHNULLCMD; Program:                 Shell Emulation.    (line   65)
* NOCSHNULLGLOB; Program:                Expansion and Globbing.
                                                             (line   52)
* NODEBUGBEFORECMD; Program:             Scripts and Functions.
                                                             (line   49)
* NODOTGLOB; Program:                    Option Aliases.     (line   14)
* NODVORAK; Program:                     Input/Output.       (line   54)
* NOEMACS; Program:                      Zle.                (line   26)
* NOEQUALS; Program:                     Expansion and Globbing.
                                                             (line   58)
* NOERREXIT; Program:                    Scripts and Functions.
                                                             (line   55)
* NOERRRETURN; Program:                  Scripts and Functions.
                                                             (line   89)
* NOEVALLINENO; Program:                 Scripts and Functions.
                                                             (line  114)
* NOEXEC; Program:                       Scripts and Functions.
                                                             (line  127)
* NOEXTENDEDGLOB; Program:               Expansion and Globbing.
                                                             (line   63)
* NOEXTENDEDHISTORY; Program:            History.            (line   21)
* NOFLOWCONTROL; Program:                Input/Output.       (line   60)
* NOFORCEFLOAT; Program:                 Expansion and Globbing.
                                                             (line   69)
* NOFUNCTIONARGZERO; Program:            Scripts and Functions.
                                                             (line  134)
* noglob; Function:                      Precommand Modifiers.
                                                             (line   58)
* NOGLOB; Program:                       Expansion and Globbing.
                                                             (line   76)
* NOGLOBALEXPORT; Program:               Initialisation.     (line   10)
* NOGLOBALRCS; Program:                  Initialisation.     (line   26)
* NOGLOBASSIGN; Program:                 Expansion and Globbing.
                                                             (line   81)
* NOGLOBCOMPLETE; Program:               Completion<2>.      (line   82)
* NOGLOBDOTS; Program:                   Expansion and Globbing.
                                                             (line   94)
* NOGLOBSTARSHORT; Program:              Expansion and Globbing.
                                                             (line   99)
* NOGLOBSUBST; Program:                  Expansion and Globbing.
                                                             (line  109)
* NOHASHALL; Program:                    Option Aliases.     (line   18)
* NOHASHCMDS; Program:                   Input/Output.       (line   81)
* NOHASHDIRS; Program:                   Input/Output.       (line   90)
* NOHASHEXECUTABLESONLY; Program:        Input/Output.       (line   96)
* NOHASHLISTALL; Program:                Completion<2>.      (line   98)
* NOHISTALLOWCLOBBER; Program:           History.            (line   29)
* NOHISTAPPEND; Program:                 Option Aliases.     (line   22)
* NOHISTBEEP; Program:                   History.            (line   34)
* NOHISTEXPAND; Program:                 Option Aliases.     (line   26)
* NOHISTEXPIREDUPSFIRST; Program:        History.            (line   39)
* NOHISTFCNTLLOCK; Program:              History.            (line   50)
* NOHISTFINDNODUPS; Program:             History.            (line   59)
* NOHISTIGNOREALLDUPS; Program:          History.            (line   65)
* NOHISTIGNOREDUPS; Program:             History.            (line   71)
* NOHISTIGNORESPACE; Program:            History.            (line   76)
* NOHISTLEXWORDS; Program:               History.            (line   87)
* NOHISTNOFUNCTIONS; Program:            History.            (line   99)
* NOHISTNOSTORE; Program:                History.            (line  106)
* NOHISTREDUCEBLANKS; Program:           History.            (line  113)
* NOHISTSAVEBYCOPY; Program:             History.            (line  118)
* NOHISTSAVENODUPS; Program:             History.            (line  134)
* NOHISTSUBSTPATTERN; Program:           Expansion and Globbing.
                                                             (line  117)
* NOHISTVERIFY; Program:                 History.            (line  139)
* NOHUP; Program:                        Job Control.        (line   43)
* NOIGNOREBRACES; Program:               Expansion and Globbing.
                                                             (line  124)
* NOIGNORECLOSEBRACES; Program:          Expansion and Globbing.
                                                             (line  129)
* NOIGNOREEOF; Program:                  Input/Output.       (line   66)
* NOINCAPPENDHISTORY; Program:           History.            (line  145)
* NOINCAPPENDHISTORYTIME; Program:       History.            (line  154)
* NOINTERACTIVE; Program:                Shell State<2>.     (line    6)
* NOINTERACTIVECOMMENTS; Program:        Input/Output.       (line   77)
* NOKSHARRAYS; Program:                  Shell Emulation.    (line   71)
* NOKSHAUTOLOAD; Program:                Shell Emulation.    (line   80)
* NOKSHGLOB; Program:                    Expansion and Globbing.
                                                             (line  149)
* NOKSHOPTIONPRINT; Program:             Shell Emulation.    (line   90)
* NOKSHTYPESET; Program:                 Shell Emulation.    (line   96)
* NOKSHZEROSUBSCRIPT; Program:           Shell Emulation.    (line  111)
* NOLISTAMBIGUOUS; Program:              Completion<2>.      (line  105)
* NOLISTBEEP; Program:                   Completion<2>.      (line  114)
* NOLISTPACKED; Program:                 Completion<2>.      (line  122)
* NOLISTROWSFIRST; Program:              Completion<2>.      (line  127)
* NOLISTTYPES; Program:                  Completion<2>.      (line  133)
* NOLOCALLOOPS; Program:                 Scripts and Functions.
                                                             (line  142)
* NOLOCALOPTIONS; Program:               Scripts and Functions.
                                                             (line  151)
* NOLOCALPATTERNS; Program:              Scripts and Functions.
                                                             (line  163)
* NOLOCALTRAPS; Program:                 Scripts and Functions.
                                                             (line  172)
* NOLOG; Program:                        Option Aliases.     (line   30)
* NOLOGIN; Program:                      Shell State<2>.     (line   16)
* NOLONGLISTJOBS; Program:               Job Control.        (line   47)
* NOMAGICEQUALSUBST; Program:            Expansion and Globbing.
                                                             (line  155)
* NOMAILWARN; Program:                   Option Aliases.     (line   34)
* NOMAILWARNING; Program:                Input/Output.       (line  105)
* NOMARKDIRS; Program:                   Expansion and Globbing.
                                                             (line  171)
* NOMATCH; Program:                      Expansion and Globbing.
                                                             (line  200)
* NOMENUCOMPLETE; Program:               Completion<2>.      (line  138)
* NOMONITOR; Program:                    Job Control.        (line   51)
* NOMULTIBYTE; Program:                  Expansion and Globbing.
                                                             (line  176)
* NOMULTIFUNCDEF; Program:               Scripts and Functions.
                                                             (line  188)
* NOMULTIOS; Program:                    Scripts and Functions.
                                                             (line  202)
* NONOMATCH; Program:                    Expansion and Globbing.
                                                             (line  200)
* NONOTIFY; Program:                     Job Control.        (line   55)
* NONULLGLOB; Program:                   Expansion and Globbing.
                                                             (line  206)
* NONUMERICGLOBSORT; Program:            Expansion and Globbing.
                                                             (line  212)
* NOOCTALZEROES; Program:                Scripts and Functions.
                                                             (line  207)
* NOONECMD; Program:                     Option Aliases.     (line   38)
* NOOVERSTRIKE; Program:                 Zle.                (line   36)
* nopatch-format; Keystroke:             Configuration<4>.   (line  318)
* NOPATHDIRS; Program:                   Input/Output.       (line  110)
* NOPATHSCRIPT; Program:                 Input/Output.       (line  125)
* NOPHYSICAL; Program:                   Option Aliases.     (line   42)
* NOPIPEFAIL; Program:                   Scripts and Functions.
                                                             (line  218)
* NOPOSIXALIASES; Program:               Shell Emulation.    (line  136)
* NOPOSIXARGZERO; Program:               Shell Emulation.    (line  153)
* NOPOSIXBUILTINS; Program:              Shell Emulation.    (line  170)
* NOPOSIXCD; Program:                    Changing Directories.
                                                             (line   60)
* NOPOSIXIDENTIFIERS; Program:           Shell Emulation.    (line  198)
* NOPOSIXJOBS; Program:                  Job Control.        (line   60)
* NOPOSIXSTRINGS; Program:               Shell Emulation.    (line  232)
* NOPOSIXTRAPS; Program:                 Shell Emulation.    (line  254)
* NOPRINTEIGHTBIT; Program:              Input/Output.       (line  133)
* NOPRINTEXITVALUE; Program:             Input/Output.       (line  139)
* NOPRIVILEGED; Program:                 Shell State<2>.     (line   22)
* NOPROMPTBANG; Program:                 Prompting.          (line    6)
* NOPROMPTCR; Program:                   Prompting.          (line   11)
* NOPROMPTPERCENT; Program:              Prompting.          (line   36)
* NOPROMPTSP; Program:                   Prompting.          (line   17)
* NOPROMPTSUBST; Program:                Prompting.          (line   41)
* NOPROMPTVARS; Program:                 Option Aliases.     (line   46)
* NOPUSHDIGNOREDUPS; Program:            Changing Directories.
                                                             (line   79)
* NOPUSHDMINUS; Program:                 Changing Directories.
                                                             (line   84)
* NOPUSHDSILENT; Program:                Changing Directories.
                                                             (line   89)
* NOPUSHDTOHOME; Program:                Changing Directories.
                                                             (line   93)
* NORCEXPANDPARAM; Program:              Expansion and Globbing.
                                                             (line  217)
* NORCQUOTES; Program:                   Input/Output.       (line  144)
* NORCS; Program:                        Initialisation.     (line   33)
* NORECEXACT; Program:                   Completion<2>.      (line  147)
* NOREMATCHPCRE; Program:                Expansion and Globbing.
                                                             (line  224)
* NORMSTARSILENT; Program:               Input/Output.       (line  151)
* NORMSTARWAIT; Program:                 Input/Output.       (line  155)
* NOSHAREHISTORY; Program:               History.            (line  168)
* NOSHFILEEXPANSION; Program:            Shell Emulation.    (line  270)
* NOSHGLOB; Program:                     Expansion and Globbing.
                                                             (line  232)
* NOSHINSTDIN; Program:                  Shell State<2>.     (line   50)
* NOSHNULLCMD; Program:                  Shell Emulation.    (line  278)
* NOSHOPTIONLETTERS; Program:            Shell Emulation.    (line  283)
* NOSHORTLOOPS; Program:                 Input/Output.       (line  163)
* NOSHORTREPEAT; Program:                Input/Output.       (line  168)
* NOSHWORDSPLIT; Program:                Shell Emulation.    (line  289)
* NOSINGLECOMMAND; Program:              Shell State<2>.     (line   65)
* NOSINGLELINEZLE; Program:              Zle.                (line   40)
* NOSOURCETRACE; Program:                Scripts and Functions.
                                                             (line  227)
* NOSTDIN; Program:                      Option Aliases.     (line   50)
* NOSUNKEYBOARDHACK; Program:            Input/Output.       (line  173)
* notification of background jobs; Command: Job Control.     (line   55)
* NOTIFY; Program:                       Job Control.        (line   55)
* NOTRACKALL; Program:                   Option Aliases.     (line   54)
* NOTRANSIENTRPROMPT; Program:           Prompting.          (line   47)
* NOTRAPSASYNC; Program:                 Shell Emulation.    (line  295)
* NOTYPESETSILENT; Program:              Scripts and Functions.
                                                             (line  236)
* NOTYPESETTOUNSET; Program:             Scripts and Functions.
                                                             (line  245)
* NOUNSET; Program:                      Expansion and Globbing.
                                                             (line  243)
* NOVERBOSE; Program:                    Scripts and Functions.
                                                             (line  252)
* NOVI; Program:                         Zle.                (line   50)
* NOWARNCREATEGLOBAL; Program:           Expansion and Globbing.
                                                             (line  250)
* NOXTRACE; Program:                     Scripts and Functions.
                                                             (line  256)
* NOZLE; Program:                        Zle.                (line   60)
* NO_ALIASES; Program:                   Input/Output.       (line    6)
* NO_ALIAS_FUNC_DEF; Program:            Scripts and Functions.
                                                             (line    6)
* NO_ALL_EXPORT; Program:                Initialisation.     (line    6)
* NO_ALWAYS_LAST_PROMPT; Program:        Completion<2>.      (line    6)
* NO_ALWAYS_TO_END; Program:             Completion<2>.      (line   12)
* NO_APPEND_CREATE; Program:             Shell Emulation.    (line    6)
* NO_APPEND_HISTORY; Program:            History.            (line    6)
* NO_AUTO_CD; Program:                   Changing Directories.
                                                             (line    6)
* NO_AUTO_CONTINUE; Program:             Job Control.        (line    6)
* NO_AUTO_LIST; Program:                 Completion<2>.      (line   19)
* NO_AUTO_MENU; Program:                 Completion<2>.      (line   23)
* NO_AUTO_NAME_DIRS; Program:            Completion<2>.      (line   29)
* NO_AUTO_PARAM_KEYS; Program:           Completion<2>.      (line   37)
* NO_AUTO_PARAM_SLASH; Program:          Completion<2>.      (line   48)
* NO_AUTO_PUSHD; Program:                Changing Directories.
                                                             (line   16)
* NO_AUTO_REMOVE_SLASH; Program:         Completion<2>.      (line   53)
* NO_AUTO_RESUME; Program:               Job Control.        (line   12)
* NO_BAD_PATTERN; Program:               Expansion and Globbing.
                                                             (line    6)
* NO_BANG_HIST; Program:                 History.            (line   16)
* NO_BARE_GLOB_QUAL; Program:            Expansion and Globbing.
                                                             (line   12)
* NO_BASH_AUTO_LIST; Program:            Completion<2>.      (line   60)
* NO_BASH_REMATCH; Program:              Shell Emulation.    (line   15)
* NO_BEEP; Program:                      Zle.                (line    6)
* NO_BG_NICE; Program:                   Job Control.        (line   17)
* NO_BRACE_CCL; Program:                 Expansion and Globbing.
                                                             (line   18)
* NO_BRACE_EXPAND; Program:              Option Aliases.     (line   10)
* NO_BSD_ECHO; Program:                  Shell Emulation.    (line   27)
* NO_CASE_GLOB; Program:                 Expansion and Globbing.
                                                             (line   24)
* NO_CASE_MATCH; Program:                Expansion and Globbing.
                                                             (line   34)
* NO_CASE_MATCH; Program <1>:            The zsh/pcre Module.
                                                             (line   99)
* NO_CASE_PATHS; Program:                Expansion and Globbing.
                                                             (line   39)
* NO_CDABLE_VARS; Program:               Changing Directories.
                                                             (line   20)
* NO_CD_SILENT; Program:                 Changing Directories.
                                                             (line   27)
* NO_CHASE_DOTS; Program:                Changing Directories.
                                                             (line   37)
* NO_CHASE_LINKS; Program:               Changing Directories.
                                                             (line   53)
* NO_CHECK_JOBS; Program:                Job Control.        (line   22)
* NO_CHECK_RUNNING_JOBS; Program:        Job Control.        (line   35)
* NO_CLOBBER; Program:                   Input/Output.       (line   10)
* NO_CLOBBER_EMPTY; Program:             Input/Output.       (line   19)
* NO_COMBINING_CHARS; Program:           Zle.                (line   10)
* NO_COMPLETE_ALIASES; Program:          Completion<2>.      (line   70)
* NO_COMPLETE_IN_WORD; Program:          Completion<2>.      (line   76)
* NO_CONTINUE_ON_ERROR; Program:         Shell Emulation.    (line   33)
* NO_CORRECT; Program:                   Input/Output.       (line   31)
* NO_CORRECT_ALL; Program:               Input/Output.       (line   44)
* NO_CSH_JUNKIE_HISTORY; Program:        Shell Emulation.    (line   43)
* NO_CSH_JUNKIE_LOOPS; Program:          Shell Emulation.    (line   51)
* NO_CSH_JUNKIE_QUOTES; Program:         Shell Emulation.    (line   56)
* NO_CSH_NULLCMD; Program:               Shell Emulation.    (line   65)
* NO_CSH_NULL_GLOB; Program:             Expansion and Globbing.
                                                             (line   52)
* NO_C_BASES; Program:                   Scripts and Functions.
                                                             (line   32)
* NO_C_PRECEDENCES; Program:             Scripts and Functions.
                                                             (line   43)
* NO_DEBUG_BEFORE_CMD; Program:          Scripts and Functions.
                                                             (line   49)
* NO_DOT_GLOB; Program:                  Option Aliases.     (line   14)
* NO_DVORAK; Program:                    Input/Output.       (line   54)
* NO_EMACS; Program:                     Zle.                (line   26)
* NO_EQUALS; Program:                    Expansion and Globbing.
                                                             (line   58)
* NO_ERR_EXIT; Program:                  Scripts and Functions.
                                                             (line   55)
* NO_ERR_RETURN; Program:                Scripts and Functions.
                                                             (line   89)
* NO_EVAL_LINENO; Program:               Scripts and Functions.
                                                             (line  114)
* NO_EXEC; Program:                      Scripts and Functions.
                                                             (line  127)
* NO_EXTENDED_GLOB; Program:             Expansion and Globbing.
                                                             (line   63)
* NO_EXTENDED_HISTORY; Program:          History.            (line   21)
* NO_FLOW_CONTROL; Program:              Input/Output.       (line   60)
* NO_FORCE_FLOAT; Program:               Expansion and Globbing.
                                                             (line   69)
* NO_FUNCTION_ARGZERO; Program:          Scripts and Functions.
                                                             (line  134)
* NO_GLOB; Program:                      Expansion and Globbing.
                                                             (line   76)
* NO_GLOBAL_EXPORT; Program:             Initialisation.     (line   10)
* NO_GLOBAL_RCS, use of; Program:        Startup/Shutdown Files.
                                                             (line    6)
* NO_GLOBAL_RCS; Program:                Initialisation.     (line   26)
* NO_GLOB_ASSIGN; Program:               Expansion and Globbing.
                                                             (line   81)
* NO_GLOB_COMPLETE; Program:             Completion<2>.      (line   82)
* NO_GLOB_DOTS; Program:                 Expansion and Globbing.
                                                             (line   94)
* NO_GLOB_STAR_SHORT; Program:           Expansion and Globbing.
                                                             (line   99)
* NO_GLOB_SUBST; Program:                Expansion and Globbing.
                                                             (line  109)
* NO_HASH_ALL; Program:                  Option Aliases.     (line   18)
* NO_HASH_CMDS; Program:                 Input/Output.       (line   81)
* NO_HASH_DIRS; Program:                 Input/Output.       (line   90)
* NO_HASH_EXECUTABLES_ONLY; Program:     Input/Output.       (line   96)
* NO_HASH_LIST_ALL; Program:             Completion<2>.      (line   98)
* NO_HIST_ALLOW_CLOBBER; Program:        History.            (line   29)
* NO_HIST_APPEND; Program:               Option Aliases.     (line   22)
* NO_HIST_BEEP; Program:                 History.            (line   34)
* NO_HIST_EXPAND; Program:               Option Aliases.     (line   26)
* NO_HIST_EXPIRE_DUPS_FIRST; Program:    History.            (line   39)
* NO_HIST_FCNTL_LOCK; Program:           History.            (line   50)
* NO_HIST_FIND_NO_DUPS; Program:         History.            (line   59)
* NO_HIST_IGNORE_ALL_DUPS; Program:      History.            (line   65)
* NO_HIST_IGNORE_DUPS; Program:          History.            (line   71)
* NO_HIST_IGNORE_SPACE; Program:         History.            (line   76)
* NO_HIST_LEX_WORDS; Program:            History.            (line   87)
* NO_HIST_NO_FUNCTIONS; Program:         History.            (line   99)
* NO_HIST_NO_STORE; Program:             History.            (line  106)
* NO_HIST_REDUCE_BLANKS; Program:        History.            (line  113)
* NO_HIST_SAVE_BY_COPY; Program:         History.            (line  118)
* NO_HIST_SAVE_NO_DUPS; Program:         History.            (line  134)
* NO_HIST_SUBST_PATTERN; Program:        Expansion and Globbing.
                                                             (line  117)
* NO_HIST_VERIFY; Program:               History.            (line  139)
* NO_HUP; Program:                       Job Control.        (line   43)
* NO_IGNORE_BRACES; Program:             Expansion and Globbing.
                                                             (line  124)
* NO_IGNORE_CLOSE_BRACES; Program:       Expansion and Globbing.
                                                             (line  129)
* NO_IGNORE_EOF; Program:                Input/Output.       (line   66)
* NO_INC_APPEND_HISTORY; Program:        History.            (line  145)
* NO_INC_APPEND_HISTORY_TIME; Program:   History.            (line  154)
* NO_INTERACTIVE; Program:               Shell State<2>.     (line    6)
* NO_INTERACTIVE_COMMENTS; Program:      Input/Output.       (line   77)
* NO_KSH_ARRAYS; Program:                Shell Emulation.    (line   71)
* NO_KSH_AUTOLOAD; Program:              Shell Emulation.    (line   80)
* NO_KSH_GLOB; Program:                  Expansion and Globbing.
                                                             (line  149)
* NO_KSH_OPTION_PRINT; Program:          Shell Emulation.    (line   90)
* NO_KSH_TYPESET; Program:               Shell Emulation.    (line   96)
* NO_KSH_ZERO_SUBSCRIPT; Program:        Shell Emulation.    (line  111)
* NO_LIST_AMBIGUOUS; Program:            Completion<2>.      (line  105)
* NO_LIST_BEEP; Program:                 Completion<2>.      (line  114)
* NO_LIST_PACKED; Program:               Completion<2>.      (line  122)
* NO_LIST_ROWS_FIRST; Program:           Completion<2>.      (line  127)
* NO_LIST_TYPES; Program:                Completion<2>.      (line  133)
* NO_LOCAL_LOOPS; Program:               Scripts and Functions.
                                                             (line  142)
* NO_LOCAL_OPTIONS; Program:             Scripts and Functions.
                                                             (line  151)
* NO_LOCAL_PATTERNS; Program:            Scripts and Functions.
                                                             (line  163)
* NO_LOCAL_TRAPS; Program:               Scripts and Functions.
                                                             (line  172)
* NO_LOG; Program:                       Option Aliases.     (line   30)
* NO_LOGIN; Program:                     Shell State<2>.     (line   16)
* NO_LONG_LIST_JOBS; Program:            Job Control.        (line   47)
* NO_MAGIC_EQUAL_SUBST; Program:         Expansion and Globbing.
                                                             (line  155)
* NO_MAIL_WARN; Program:                 Option Aliases.     (line   34)
* NO_MAIL_WARNING; Program:              Input/Output.       (line  105)
* NO_MARK_DIRS; Program:                 Expansion and Globbing.
                                                             (line  171)
* NO_MENU_COMPLETE; Program:             Completion<2>.      (line  138)
* NO_MONITOR; Program:                   Job Control.        (line   51)
* NO_MULTIBYTE; Program:                 Expansion and Globbing.
                                                             (line  176)
* NO_MULTIOS; Program:                   Scripts and Functions.
                                                             (line  202)
* NO_MULTI_FUNC_DEF; Program:            Scripts and Functions.
                                                             (line  188)
* NO_NOMATCH; Program:                   Expansion and Globbing.
                                                             (line  200)
* NO_NOTIFY; Program:                    Job Control.        (line   55)
* NO_NULL_GLOB; Program:                 Expansion and Globbing.
                                                             (line  206)
* NO_NUMERIC_GLOB_SORT; Program:         Expansion and Globbing.
                                                             (line  212)
* NO_OCTAL_ZEROES; Program:              Scripts and Functions.
                                                             (line  207)
* NO_ONE_CMD; Program:                   Option Aliases.     (line   38)
* NO_OVERSTRIKE; Program:                Zle.                (line   36)
* NO_PATH_DIRS; Program:                 Input/Output.       (line  110)
* NO_PATH_SCRIPT; Program:               Input/Output.       (line  125)
* NO_PHYSICAL; Program:                  Option Aliases.     (line   42)
* NO_PIPE_FAIL; Program:                 Scripts and Functions.
                                                             (line  218)
* NO_POSIX_ALIASES; Program:             Shell Emulation.    (line  136)
* NO_POSIX_ARGZERO; Program:             Shell Emulation.    (line  153)
* NO_POSIX_BUILTINS; Program:            Shell Emulation.    (line  170)
* NO_POSIX_CD; Program:                  Changing Directories.
                                                             (line   60)
* NO_POSIX_IDENTIFIERS; Program:         Shell Emulation.    (line  198)
* NO_POSIX_JOBS; Program:                Job Control.        (line   60)
* NO_POSIX_STRINGS; Program:             Shell Emulation.    (line  232)
* NO_POSIX_TRAPS; Program:               Shell Emulation.    (line  254)
* NO_PRINT_EIGHT_BIT; Program:           Input/Output.       (line  133)
* NO_PRINT_EXIT_VALUE; Program:          Input/Output.       (line  139)
* NO_PRIVILEGED; Program:                Shell State<2>.     (line   22)
* NO_PROMPT_BANG; Program:               Prompting.          (line    6)
* NO_PROMPT_CR; Program:                 Prompting.          (line   11)
* NO_PROMPT_PERCENT; Program:            Prompting.          (line   36)
* NO_PROMPT_SP; Program:                 Prompting.          (line   17)
* NO_PROMPT_SUBST; Program:              Prompting.          (line   41)
* NO_PROMPT_VARS; Program:               Option Aliases.     (line   46)
* NO_PUSHD_IGNORE_DUPS; Program:         Changing Directories.
                                                             (line   79)
* NO_PUSHD_MINUS; Program:               Changing Directories.
                                                             (line   84)
* NO_PUSHD_SILENT; Program:              Changing Directories.
                                                             (line   89)
* NO_PUSHD_TO_HOME; Program:             Changing Directories.
                                                             (line   93)
* NO_RCS, use of; Program:               Startup/Shutdown Files.
                                                             (line    6)
* NO_RCS; Program:                       Initialisation.     (line   33)
* NO_RC_EXPAND_PARAM; Program:           Expansion and Globbing.
                                                             (line  217)
* NO_RC_QUOTES; Program:                 Input/Output.       (line  144)
* NO_REC_EXACT; Program:                 Completion<2>.      (line  147)
* NO_REMATCH_PCRE; Program:              Expansion and Globbing.
                                                             (line  224)
* NO_RM_STAR_SILENT; Program:            Input/Output.       (line  151)
* NO_RM_STAR_WAIT; Program:              Input/Output.       (line  155)
* NO_SHARE_HISTORY; Program:             History.            (line  168)
* NO_SHIN_STDIN; Program:                Shell State<2>.     (line   50)
* NO_SHORT_LOOPS; Program:               Input/Output.       (line  163)
* NO_SHORT_REPEAT; Program:              Input/Output.       (line  168)
* NO_SH_FILE_EXPANSION; Program:         Shell Emulation.    (line  270)
* NO_SH_GLOB; Program:                   Expansion and Globbing.
                                                             (line  232)
* NO_SH_NULLCMD; Program:                Shell Emulation.    (line  278)
* NO_SH_OPTION_LETTERS; Program:         Shell Emulation.    (line  283)
* NO_SH_WORD_SPLIT; Program:             Shell Emulation.    (line  289)
* NO_SINGLE_COMMAND; Program:            Shell State<2>.     (line   65)
* NO_SINGLE_LINE_ZLE; Program:           Zle.                (line   40)
* NO_SOURCE_TRACE; Program:              Scripts and Functions.
                                                             (line  227)
* NO_STDIN; Program:                     Option Aliases.     (line   50)
* NO_SUN_KEYBOARD_HACK; Program:         Input/Output.       (line  173)
* NO_TRACK_ALL; Program:                 Option Aliases.     (line   54)
* NO_TRANSIENT_RPROMPT; Program:         Prompting.          (line   47)
* NO_TRAPS_ASYNC; Program:               Shell Emulation.    (line  295)
* NO_TYPESET_SILENT; Program:            Scripts and Functions.
                                                             (line  236)
* NO_TYPESET_TO_UNSET; Program:          Scripts and Functions.
                                                             (line  245)
* NO_UNSET; Program:                     Expansion and Globbing.
                                                             (line  243)
* NO_VERBOSE; Program:                   Scripts and Functions.
                                                             (line  252)
* NO_VI; Program:                        Zle.                (line   50)
* NO_WARNNESTEDVAR; Program:             Expansion and Globbing.
                                                             (line  260)
* NO_WARN_CREATE_GLOBAL; Program:        Expansion and Globbing.
                                                             (line  250)
* NO_WARN_NESTED_VAR; Program:           Expansion and Globbing.
                                                             (line  260)
* NO_XTRACE; Program:                    Scripts and Functions.
                                                             (line  256)
* NO_ZLE; Program:                       Zle.                (line   60)
* nslookup; Function:                    Descriptions.       (line  124)
* null command style; Command:           Parameters Used by the Shell.
                                                             (line  324)
* null globbing style, csh; Command:     Expansion and Globbing.
                                                             (line   52)
* NULLCMD, ignoring; Variable:           Shell Emulation.    (line   65)
* NULLCMD, ignoring; Variable <1>:       Shell Emulation.    (line  278)
* NULLCMD, use of; Variable:             Redirections with no command.
                                                             (line   10)
* NULLCMD; Variable:                     Parameters Used by the Shell.
                                                             (line  324)
* NULLGLOB; Program:                     Expansion and Globbing.
                                                             (line  206)
* nulls, embedded in $’...’; Command:    Shell Emulation.    (line  232)
* NULL_GLOB; Program:                    Expansion and Globbing.
                                                             (line  206)
* numbers, completion style; Keystroke:  Standard Styles.    (line 1168)
* NUMERIC; Variable:                     User-Defined Widgets.
                                                             (line  171)
* NUMERICGLOBSORT; Program:              Expansion and Globbing.
                                                             (line  212)
* NUMERIC_GLOB_SORT; Program:            Expansion and Globbing.
                                                             (line  212)
* nvcsformats; Keystroke:                Configuration<4>.   (line   93)
* octal, arithmetic expressions; Command: Scripts and Functions.
                                                             (line  207)
* octal, output in C format; Command:    Scripts and Functions.
                                                             (line   32)
* OCTALZEROES; Program:                  Scripts and Functions.
                                                             (line  207)
* OCTAL_ZEROES, use of; Program:         Arithmetic Evaluation.
                                                             (line   93)
* OCTAL_ZEROES; Program:                 Scripts and Functions.
                                                             (line  207)
* old-list, completion style; Keystroke: Standard Styles.    (line 1178)
* old-matches, completion style; Keystroke: Standard Styles. (line 1208)
* old-menu, completion style; Keystroke: Standard Styles.    (line 1221)
* OLDPWD; Variable:                      Parameters Set by the Shell.
                                                             (line  192)
* old_insert, compstate; Variable:       Completion Special Parameters.
                                                             (line  272)
* old_list, compstate; Variable:         Completion Special Parameters.
                                                             (line  286)
* ONECMD; Program:                       Option Aliases.     (line   38)
* ONE_CMD; Program:                      Option Aliases.     (line   38)
* operator precedence; Command:          Scripts and Functions.
                                                             (line   43)
* operators, arithmetic; Command:        Arithmetic Evaluation.
                                                             (line  138)
* OPTARG, use of; Variable:              Shell Builtin Commands.
                                                             (line 1078)
* OPTARG; Variable:                      Parameters Set by the Shell.
                                                             (line  197)
* OPTIND; Variable:                      Parameters Set by the Shell.
                                                             (line  202)
* option printing style, ksh; Command:   Shell Emulation.    (line   90)
* option printing, ksh style; Command:   Shell Emulation.    (line   90)
* options, aliases; Command:             Option Aliases.     (line    6)
* options, completion tag; Keystroke:    Standard Tags.      (line  242)
* options, description; Command:         Description of Options.
                                                             (line    6)
* options, processing; Command:          Shell Builtin Commands.
                                                             (line 1060)
* options, setting; Command:             Shell Builtin Commands.
                                                             (line 1932)
* options, shell; Command:               Invocation<2>.      (line    6)
* options, single letter, ksh style; Command: Shell Emulation.
                                                             (line  283)
* options, single letter; Command:       Single Letter Options.
                                                             (line    6)
* options, specifying; Command:          Specifying Options. (line    6)
* options, unsetting; Command:           Shell Builtin Commands.
                                                             (line 2797)
* options; Command:                      Options<2>.         (line    6)
* options; Variable:                     The zsh/parameter Module.
                                                             (line    9)
* opt_args, use of; Variable:            Utility Functions.  (line  463)
* original, completion style; Keystroke: Standard Styles.    (line 1239)
* original, completion tag; Keystroke:   Standard Tags.      (line  246)
* OSTYPE; Variable:                      Parameters Set by the Shell.
                                                             (line  207)
* other-accounts, completion tag; Keystroke: Standard Tags.  (line  251)
* overstrike mode, of editor; Command:   Zle.                (line   36)
* OVERSTRIKE; Program:                   Zle.                (line   36)
* overwrite-mode; Type:                  Modifying Text.     (line  188)
* packages, completion tag; Keystroke:   Standard Tags.      (line  255)
* packageset, completion style; Keystroke: Standard Styles.  (line 1250)
* pager, MIME style; Keystroke:          MIME Functions.     (line  250)
* pager, nslookup style; Keystroke:      Styles<3>.          (line   13)
* parameter expansion flags; Command:    Parameter Expansion Flags.
                                                             (line    6)
* parameter expansion rules; Command:    Rules.              (line    6)
* parameter expansion style, rc; Command: Expansion and Globbing.
                                                             (line  217)
* parameter expansion, examples; Command: Examples.          (line    6)
* parameter expansion; Command:          Parameter Expansion.
                                                             (line    6)
* parameter modifiers; Command:          Modifiers.          (line    6)
* parameter names, non-portable characters in; Command: Shell Emulation.
                                                             (line  198)
* parameter, compstate; Variable:        Completion Special Parameters.
                                                             (line  301)
* parameter, file access via; Command:   The zsh/mapfile Module.
                                                             (line    6)
* parameters, array; Command:            Description<2>.     (line   16)
* parameters, array; Command <1>:        Description<2>.     (line   82)
* parameters, associative array; Command: Description<2>.    (line   16)
* parameters, completion tag; Keystroke: Standard Tags.      (line  259)
* parameters, declaring; Command:        Shell Builtin Commands.
                                                             (line 2116)
* parameters, editing; Command:          Zle Builtins.       (line  244)
* parameters, editor; Command:           User-Defined Widgets.
                                                             (line   15)
* parameters, expanding; Command:        Shell Builtin Commands.
                                                             (line   65)
* parameters, floating point; Command:   Arithmetic Evaluation.
                                                             (line  320)
* parameters, for using file descriptors; Command: Redirection.
                                                             (line  171)
* parameters, ksh; Command:              Ksh Parameters.     (line    6)
* parameters, listing; Command:          Shell Builtin Commands.
                                                             (line 1878)
* parameters, local; Command:            Positional Parameters.
                                                             (line   27)
* parameters, marking readonly; Command: Shell Builtin Commands.
                                                             (line 1840)
* parameters, nameref; Command:          Named References.   (line    6)
* parameters, positional; Command:       Subscript Parsing.  (line  113)
* parameters, positional; Command <1>:   Shell Builtin Commands.
                                                             (line 1878)
* parameters, positional; Command <2>:   Shell Builtin Commands.
                                                             (line 1961)
* parameters, scalar; Command:           Description<2>.     (line   16)
* parameters, setting array; Command:    Shell Builtin Commands.
                                                             (line 1878)
* parameters, setting; Command:          Shell Builtin Commands.
                                                             (line 2116)
* parameters, special; Command:          Description<2>.     (line   33)
* parameters, special; Command <1>:      The zsh/parameter Module.
                                                             (line    6)
* parameters, special; Command <2>:      The zsh/zleparameter Module.
                                                             (line    6)
* parameters, substituting unset; Command: Expansion and Globbing.
                                                             (line  243)
* parameters, unsetting; Command:        Shell Builtin Commands.
                                                             (line 2772)
* parameters, warning when created globally; Command: Expansion and Globbing.
                                                             (line  250)
* parameters, warning when setting in enclosing scope; Command: Expansion and Globbing.
                                                             (line  260)
* parameters, zle; Command:              User-Defined Widgets.
                                                             (line   15)
* parameters; Command:                   Parameters.         (line    6)
* parameters; Variable:                  The zsh/parameter Module.
                                                             (line  118)
* patch-format; Keystroke:               Configuration<4>.   (line  318)
* patchars; Variable:                    The zsh/parameter Module.
                                                             (line   85)
* path search, extended; Command:        Input/Output.       (line  110)
* path search, for script argument to shell; Command: Input/Output.
                                                             (line  125)
* path, completion style; Keystroke:     Standard Styles.    (line 1262)
* path, use of; Variable:                Command Execution.  (line   11)
* path-completion, completion style; Keystroke: Standard Styles.
                                                             (line 1270)
* path-directories, completion tag; Keystroke: Standard Tags.
                                                             (line  263)
* path; Variable:                        Parameters Used by the Shell.
                                                             (line  331)
* PATH; Variable:                        Parameters Used by the Shell.
                                                             (line  331)
* PATHDIRS; Program:                     Input/Output.       (line  110)
* paths, completion tag; Keystroke:      Standard Tags.      (line  269)
* PATHSCRIPT; Program:                   Input/Output.       (line  125)
* PATH_DIRS; Program:                    Input/Output.       (line  110)
* PATH_SCRIPT; Program:                  Input/Output.       (line  125)
* pattern_insert, compstate; Variable:   Completion Special Parameters.
                                                             (line  306)
* pattern_match, compstate; Variable:    Completion Special Parameters.
                                                             (line  316)
* PCRE, regexp; Command:                 Expansion and Globbing.
                                                             (line  224)
* pcre-match; Function:                  The zsh/pcre Module.
                                                             (line   90)
* pcre_compile; Function:                The zsh/pcre Module.
                                                             (line    8)
* pcre_match; Function:                  The zsh/pcre Module.
                                                             (line   25)
* pcre_study; Function:                  The zsh/pcre Module.
                                                             (line   20)
* PENDING; Variable:                     User-Defined Widgets.
                                                             (line  179)
* PERIOD; Variable:                      Hook Functions.     (line   27)
* periodic; Function:                    Hook Functions.     (line   25)
* periodic_functions; Variable:          Hook Functions.     (line   25)
* PHYSICAL; Program:                     Option Aliases.     (line   42)
* pick-web-browser; Function:            MIME Functions.     (line  301)
* pid, sysparams; Variable:              Parameters<4>.      (line   24)
* pine-directory, completion style; Keystroke: Standard Styles.
                                                             (line 1286)
* PIPEFAIL; Program:                     Scripts and Functions.
                                                             (line  218)
* pipeline, exit status from; Command:   Scripts and Functions.
                                                             (line  218)
* pipeline; Command:                     Simple Commands & Pipelines.
                                                             (line   21)
* pipestatus; Variable:                  Parameters Set by the Shell.
                                                             (line   86)
* PIPE_FAIL; Program:                    Scripts and Functions.
                                                             (line  218)
* pods, completion tag; Keystroke:       Standard Tags.      (line  274)
* popd; Function:                        Shell Builtin Commands.
                                                             (line 1437)
* ports, completion style; Keystroke:    Standard Styles.    (line 1292)
* ports, completion tag; Keystroke:      Standard Tags.      (line  278)
* positional parameters; Command:        Subscript Parsing.  (line  114)
* POSIXALIASES; Program:                 Shell Emulation.    (line  136)
* POSIXARGZERO; Program:                 Shell Emulation.    (line  153)
* POSIXBUILTINS; Program:                Shell Emulation.    (line  170)
* POSIXCD; Program:                      Changing Directories.
                                                             (line   60)
* POSIXIDENTIFIERS; Program:             Shell Emulation.    (line  198)
* POSIXJOBS; Program:                    Job Control.        (line   60)
* POSIXSTRINGS; Program:                 Shell Emulation.    (line  232)
* POSIXTRAPS; Program:                   Shell Emulation.    (line  254)
* POSIX_ALIASES; Program:                Shell Emulation.    (line  136)
* POSIX_ARGZERO; Program:                Shell Emulation.    (line  153)
* POSIX_BUILTINS; Program:               Shell Emulation.    (line  170)
* POSIX_CD; Program:                     Changing Directories.
                                                             (line   60)
* POSIX_IDENTIFIERS; Program:            Shell Emulation.    (line  198)
* POSIX_JOBS; Program:                   Job Control.        (line   60)
* POSIX_STRINGS; Program:                Shell Emulation.    (line  232)
* POSIX_TRAPS; Program:                  Shell Emulation.    (line  254)
* POSTDISPLAY; Variable:                 User-Defined Widgets.
                                                             (line  200)
* POSTEDIT; Variable:                    Parameters Used by the Shell.
                                                             (line  338)
* pound-insert; Type:                    Miscellaneous.      (line  148)
* ppid, sysparams; Variable:             Parameters<4>.      (line   30)
* PPID; Variable:                        Parameters Set by the Shell.
                                                             (line  211)
* PREBUFFER; Variable:                   User-Defined Widgets.
                                                             (line  187)
* precedence of glob operators; Command: Precedence.         (line    6)
* precedence, operator; Command:         Scripts and Functions.
                                                             (line   43)
* precmd; Function:                      Hook Functions.     (line   34)
* precmd_functions; Variable:            Hook Functions.     (line   34)
* precommand modifiers; Command:         Precommand Modifiers.
                                                             (line    6)
* predict-off; Type:                     Widgets.            (line 1168)
* predict-on; Type:                      Widgets.            (line 1168)
* PREDISPLAY; Variable:                  User-Defined Widgets.
                                                             (line  193)
* preexec; Function:                     Hook Functions.     (line   41)
* preexec_functions; Variable:           Hook Functions.     (line   41)
* prefix-hidden, completion style; Keystroke: Standard Styles.
                                                             (line 1298)
* prefix-needed, completion style; Keystroke: Standard Styles.
                                                             (line 1306)
* PREFIX; Variable:                      Completion Special Parameters.
                                                             (line   48)
* prefixes, completion tag; Keystroke:   Standard Tags.      (line  282)
* preserve-prefix, completion style; Keystroke: Standard Styles.
                                                             (line 1331)
* print; Function:                       Shell Builtin Commands.
                                                             (line 1455)
* PRINTEIGHTBIT; Program:                Input/Output.       (line  133)
* printers, completion tag; Keystroke:   Standard Tags.      (line  286)
* PRINTEXITVALUE; Program:               Input/Output.       (line  139)
* printf; Function:                      Shell Builtin Commands.
                                                             (line 1615)
* PRINT_EIGHT_BIT; Program:              Input/Output.       (line  133)
* PRINT_EXIT_VALUE; Program:             Input/Output.       (line  139)
* priority of background jobs; Command:  Job Control.        (line   17)
* private parameter, creating; Command:  The zsh/param/private Module.
                                                             (line   12)
* private; Function:                     The zsh/param/private Module.
                                                             (line   12)
* privileged mode; Command:              Shell State<2>.     (line   22)
* PRIVILEGED; Program:                   Shell State<2>.     (line   22)
* process substitution; Command:         Process Substitution.
                                                             (line    6)
* processes, completion tag; Keystroke:  Standard Tags.      (line  290)
* processes-names, completion tag; Keystroke: Standard Tags. (line  294)
* progress, zftp style; Keystroke:       Configuration.      (line   22)
* prompt expansion; Command:             Expansion of Prompt Sequences.
                                                             (line    6)
* prompt, ! expansion; Command:          Prompting.          (line    6)
* prompt, % expansion; Command:          Prompting.          (line   36)
* prompt, nslookup style; Keystroke:     Styles<3>.          (line   19)
* prompt, parameter expansion; Command:  Prompting.          (line   41)
* prompt, save partial lines; Command:   Prompting.          (line   17)
* prompt, widget style; Keystroke:       Styles<2>.          (line  103)
* prompt, with CR; Command:              Prompting.          (line   11)
* PROMPT2; Variable:                     Parameters Used by the Shell.
                                                             (line  345)
* PROMPT3; Variable:                     Parameters Used by the Shell.
                                                             (line  347)
* PROMPT4; Variable:                     Parameters Used by the Shell.
                                                             (line  349)
* PROMPT; Variable:                      Parameters Used by the Shell.
                                                             (line  343)
* prompt; Variable:                      Parameters Used by the Shell.
                                                             (line  353)
* PROMPTBANG; Program:                   Prompting.          (line    6)
* PROMPTCR; Program:                     Prompting.          (line   11)
* PROMPTPERCENT; Program:                Prompting.          (line   36)
* PROMPTSP; Program:                     Prompting.          (line   17)
* PROMPTSUBST; Program:                  Prompting.          (line   41)
* PROMPTVARS; Program:                   Option Aliases.     (line   46)
* PROMPT_BANG, use of; Program:          Expansion of Prompt Sequences.
                                                             (line   18)
* PROMPT_BANG; Program:                  Prompting.          (line    6)
* PROMPT_CR; Program:                    Prompting.          (line   11)
* PROMPT_EOL_MARK; Variable:             Parameters Used by the Shell.
                                                             (line  357)
* PROMPT_PERCENT, use of; Program:       Expansion of Prompt Sequences.
                                                             (line   22)
* PROMPT_PERCENT; Program:               Prompting.          (line   36)
* PROMPT_SP; Program:                    Prompting.          (line   17)
* PROMPT_SUBST, use of; Program:         Expansion of Prompt Sequences.
                                                             (line   10)
* PROMPT_SUBST; Program:                 Prompting.          (line   41)
* PROMPT_VARS; Program:                  Option Aliases.     (line   46)
* PS1; Variable:                         Parameters Used by the Shell.
                                                             (line  365)
* PS2; Variable:                         Parameters Used by the Shell.
                                                             (line  371)
* PS3; Variable:                         Parameters Used by the Shell.
                                                             (line  378)
* PS4; Variable:                         Parameters Used by the Shell.
                                                             (line  383)
* psvar, use of; Variable:               Conditional Substrings in Prompts.
                                                             (line    8)
* psvar; Variable:                       Parameters Used by the Shell.
                                                             (line  389)
* PSVAR; Variable:                       Parameters Used by the Shell.
                                                             (line  389)
* push-input; Type:                      Miscellaneous.      (line  162)
* push-line-or-edit; Type:               Miscellaneous.      (line  177)
* push-line; Type:                       Miscellaneous.      (line  171)
* pushd, making cd behave like; Command: Changing Directories.
                                                             (line   16)
* pushd, to home; Command:               Changing Directories.
                                                             (line   93)
* pushd; Function:                       Shell Builtin Commands.
                                                             (line 1651)
* PUSHDIGNOREDUPS; Program:              Changing Directories.
                                                             (line   79)
* PUSHDMINUS; Program:                   Changing Directories.
                                                             (line   84)
* PUSHDSILENT; Program:                  Changing Directories.
                                                             (line   89)
* PUSHDTOHOME; Program:                  Changing Directories.
                                                             (line   93)
* PUSHD_IGNORE_DUPS; Program:            Changing Directories.
                                                             (line   79)
* PUSHD_MINUS, use of; Program:          Shell Builtin Commands.
                                                             (line 1651)
* PUSHD_MINUS; Program:                  Changing Directories.
                                                             (line   84)
* PUSHD_SILENT, use of; Program:         Shell Builtin Commands.
                                                             (line 1651)
* PUSHD_SILENT; Program:                 Changing Directories.
                                                             (line   89)
* PUSHD_TO_HOME, use of; Program:        Shell Builtin Commands.
                                                             (line 1651)
* PUSHD_TO_HOME; Program:                Changing Directories.
                                                             (line   93)
* pushln; Function:                      Shell Builtin Commands.
                                                             (line 1686)
* put-replace-selection; Type:           Modifying Text.     (line  204)
* pwd; Function:                         Shell Builtin Commands.
                                                             (line 1690)
* PWD; Variable:                         Parameters Set by the Shell.
                                                             (line  217)
* QIPREFIX; Variable:                    Completion Special Parameters.
                                                             (line   54)
* QISUFFIX; Variable:                    Completion Special Parameters.
                                                             (line   62)
* qualifiers, globbing; Command:         Glob Qualifiers.    (line    6)
* querying before rm *; Command:         Input/Output.       (line  151)
* quilt-patch-dir; Keystroke:            Configuration<4>.   (line  164)
* quilt-standalone; Keystroke:           Configuration<4>.   (line  153)
* quiltcommand; Keystroke:               Configuration<4>.   (line  173)
* quote, compstate; Variable:            Completion Special Parameters.
                                                             (line  332)
* quote-line; Type:                      Modifying Text.     (line  222)
* quote-region; Type:                    Modifying Text.     (line  228)
* quoted-insert; Type:                   Modifying Text.     (line  211)
* quoting style, csh; Command:           Shell Emulation.    (line   56)
* quoting style, rc; Command:            Input/Output.       (line  144)
* quoting, compstate; Variable:          Completion Special Parameters.
                                                             (line  338)
* quoting; Command:                      Quoting.            (line    6)
* r; Function:                           Shell Builtin Commands.
                                                             (line 1697)
* RANDOM; Variable:                      Parameters Set by the Shell.
                                                             (line  222)
* range, completion style; Keystroke:    Standard Styles.    (line 1341)
* RBUFFER; Variable:                     User-Defined Widgets.
                                                             (line  207)
* rc, array expansion style; Command:    Parameter Expansion.
                                                             (line  333)
* rc, parameter expansion style; Command: Expansion and Globbing.
                                                             (line  217)
* rc, quoting style; Command:            Input/Output.       (line  144)
* RCEXPANDPARAM; Program:                Expansion and Globbing.
                                                             (line  217)
* RCQUOTES; Program:                     Input/Output.       (line  144)
* RCS, use of; Program:                  Startup/Shutdown Files.
                                                             (line    6)
* RCS; Program:                          Initialisation.     (line   33)
* RC_EXPAND_PARAM, toggle; Program:      Parameter Expansion.
                                                             (line  333)
* RC_EXPAND_PARAM; Program:              Expansion and Globbing.
                                                             (line  217)
* RC_QUOTES, use of; Program:            Quoting.            (line   14)
* RC_QUOTES; Program:                    Input/Output.       (line  144)
* read-command; Type:                    Miscellaneous.      (line  184)
* read-from-minibuffer; Type:            Widgets.            (line 1214)
* read; Function:                        Shell Builtin Commands.
                                                             (line 1701)
* reading a line; Command:               Shell Builtin Commands.
                                                             (line 1055)
* READNULLCMD, ignoring; Variable:       Shell Emulation.    (line   65)
* READNULLCMD, ignoring; Variable <1>:   Shell Emulation.    (line  278)
* READNULLCMD, use of; Variable:         Redirections with no command.
                                                             (line   18)
* READNULLCMD; Variable:                 Parameters Used by the Shell.
                                                             (line  395)
* readonly; Function:                    Shell Builtin Commands.
                                                             (line 1840)
* rebinding keys; Command:               Zle Builtins.       (line   12)
* rebinding widgets; Command:            Zle Builtins.       (line  296)
* recent directories, maintaining list of; Command: Manipulating Hook Functions.
                                                             (line   91)
* RECEXACT; Program:                     Completion<2>.      (line  147)
* recursive globbing; Command:           Recursive Globbing. (line    6)
* recursive-edit; Type:                  Miscellaneous.      (line  194)
* recursive-files, completion style; Keystroke: Standard Styles.
                                                             (line 1358)
* REC_EXACT; Program:                    Completion<2>.      (line  147)
* redirect, compstate; Variable:         Completion Special Parameters.
                                                             (line  345)
* redirection, current shell’s I/O; Command: Shell Builtin Commands.
                                                             (line  748)
* redirection; Command:                  Redirection.        (line    6)
* redirections with no command, csh; Command: Shell Emulation.
                                                             (line   65)
* redirections with no command, ksh; Command: Shell Emulation.
                                                             (line  278)
* redirections with no command, sh; Command: Shell Emulation.
                                                             (line  278)
* redisplay; Type:                       Miscellaneous.      (line  237)
* redo; Type:                            Miscellaneous.      (line  342)
* reference variables; Command:          Named References.   (line    6)
* reference, named; Command:             Shell Builtin Commands.
                                                             (line 2239)
* references, named; Command:            Local Parameters.   (line   36)
* referring to jobs; Command:            Jobs.               (line   72)
* reformat-date; Keystroke:              Styles.             (line   40)
* regex-match; Function:                 The zsh/regex Module.
                                                             (line    8)
* regex; Command:                        The zsh/regex Module.
                                                             (line    6)
* regexp, bash BASH_REMATCH variable; Command: Shell Emulation.
                                                             (line   15)
* regexp, PCRE; Command:                 Expansion and Globbing.
                                                             (line  224)
* regexp-replace; Function:              Descriptions.       (line  136)
* region, highlighting; Command:         Character Highlighting.
                                                             (line   19)
* REGION_ACTIVE; Variable:               User-Defined Widgets.
                                                             (line  214)
* region_highlight; Variable:            User-Defined Widgets.
                                                             (line  222)
* registers; Variable:                   User-Defined Widgets.
                                                             (line  281)
* regular expressions, case-insensitive matching, option; Command: Expansion and Globbing.
                                                             (line   34)
* regular expressions, perl-compatible; Command: The zsh/pcre Module.
                                                             (line    6)
* regular expressions; Command:          The zsh/regex Module.
                                                             (line    6)
* regular, completion style; Keystroke:  Standard Styles.    (line 1381)
* rehash, completion style; Keystroke:   Standard Styles.    (line 1389)
* rehash; Function:                      Shell Builtin Commands.
                                                             (line 1845)
* REMATCHPCRE; Program:                  Expansion and Globbing.
                                                             (line  224)
* REMATCH_PCRE; Program:                 Expansion and Globbing.
                                                             (line  224)
* REMATCH_PCRE; Program <1>:             The zsh/pcre Module.
                                                             (line   99)
* remote-access, completion style; Keystroke: Standard Styles.
                                                             (line 1397)
* remote-glob, zftp style; Keystroke:    Configuration.      (line   47)
* removable suffix, highlighting in completion; Command: Character Highlighting.
                                                             (line   47)
* remove-all-dups, completion style; Keystroke: Standard Styles.
                                                             (line 1406)
* repeat loops; Command:                 Complex Commands.   (line   57)
* repeat; Function:                      Complex Commands.   (line   57)
* replace-argument-edit; Type:           Widgets.            (line 1245)
* replace-argument; Type:                Widgets.            (line 1245)
* replace-pattern; Type:                 Widgets.            (line 1271)
* replace-string-again; Type:            Widgets.            (line 1271)
* replace-string; Type:                  Widgets.            (line 1271)
* REPLY, use of; Variable:               Glob Qualifiers.    (line  194)
* reply, use of; Variable:               Glob Qualifiers.    (line  194)
* REPLY, use of; Variable <1>:           Shell Builtin Commands.
                                                             (line 1706)
* reply, use of; Variable <1>:           Shell Builtin Commands.
                                                             (line 1706)
* reply, use of; Variable <2>:           Flags with Arguments.
                                                             (line   42)
* reply, use of; Variable <3>:           Control Flags.      (line  106)
* reply, use of; Variable <4>:           The zsh/zutil Module.
                                                             (line   89)
* REPLY; Variable:                       Parameters Used by the Shell.
                                                             (line  423)
* reply; Variable:                       Parameters Used by the Shell.
                                                             (line  433)
* reporter utility; Command:             Dumping Shell State.
                                                             (line    6)
* reporter; Function:                    Dumping Shell State.
                                                             (line   47)
* REPORTMEMORY; Variable:                Parameters Used by the Shell.
                                                             (line  400)
* REPORTTIME; Variable:                  Parameters Used by the Shell.
                                                             (line  414)
* reserved words; Command:               Reserved Words.     (line    6)
* reset-prompt; Type:                    Miscellaneous.      (line  241)
* resource limits; Command:              Shell Builtin Commands.
                                                             (line 1246)
* resource limits; Command <1>:          Shell Builtin Commands.
                                                             (line 2589)
* resource limits; Command <2>:          Shell Builtin Commands.
                                                             (line 2760)
* restore, compstate; Variable:          Completion Special Parameters.
                                                             (line  350)
* resuming jobs automatically; Command:  Job Control.        (line   12)
* reswords; Variable:                    The zsh/parameter Module.
                                                             (line   77)
* return from function, on error; Command: Scripts and Functions.
                                                             (line   89)
* return, use of; Function:              Functions.          (line   54)
* return; Function:                      Shell Builtin Commands.
                                                             (line 1849)
* reverse-menu-complete; Type:           Completion<3>.      (line   63)
* rm *, querying before; Command:        Input/Output.       (line  151)
* rm *, waiting before; Command:         Input/Output.       (line  155)
* rm; Function:                          The zsh/files Module.
                                                             (line  158)
* rmdir; Function:                       The zsh/files Module.
                                                             (line  191)
* rmshadow; Function:                    Descriptions.       (line  102)
* RMSTARSILENT; Program:                 Input/Output.       (line  151)
* RMSTARWAIT; Program:                   Input/Output.       (line  155)
* RM_STAR_SILENT; Program:               Input/Output.       (line  151)
* RM_STAR_WAIT; Program:                 Input/Output.       (line  155)
* roadmap; Command:                      Roadmap.            (line    6)
* rprompt, nslookup style; Keystroke:    Styles<3>.          (line   19)
* RPROMPT2; Variable:                    Parameters Used by the Shell.
                                                             (line  446)
* RPROMPT; Variable:                     Parameters Used by the Shell.
                                                             (line  437)
* RPS1; Variable:                        Parameters Used by the Shell.
                                                             (line  439)
* RPS2; Variable:                        Parameters Used by the Shell.
                                                             (line  448)
* rules, parameter expansion; Command:   Rules.              (line    6)
* run-help, use of; Function:            Accessing On-Line Help.
                                                             (line   40)
* run-help-btrfs; Function:              Descriptions.       (line  201)
* run-help-git; Function:                Descriptions.       (line  201)
* run-help-ip; Function:                 Descriptions.       (line  201)
* run-help-openssl; Function:            Descriptions.       (line  201)
* run-help-p4; Function:                 Descriptions.       (line  201)
* run-help-sudo; Function:               Descriptions.       (line  201)
* run-help-svk; Function:                Descriptions.       (line  201)
* run-help-svn; Function:                Descriptions.       (line  201)
* run-help; Function:                    Descriptions.       (line  163)
* run-help; Type:                        Miscellaneous.      (line  265)
* saliases; Variable:                    The zsh/parameter Module.
                                                             (line  110)
* SAVEHIST; Variable:                    Parameters Used by the Shell.
                                                             (line  455)
* scalar; Command:                       Description<2>.     (line   16)
* sched; Function:                       The zsh/sched Module.
                                                             (line    9)
* SECONDS; Variable:                     Parameters Set by the Shell.
                                                             (line  242)
* select, system call; Command:          The zsh/zselect Module.
                                                             (line    8)
* select-a-blank-word; Type:             Text Objects.       (line   13)
* select-a-shell-word; Type:             Text Objects.       (line   19)
* select-a-word; Type:                   Text Objects.       (line   24)
* select-in-blank-word; Type:            Text Objects.       (line   30)
* select-in-shell-word; Type:            Text Objects.       (line   36)
* select-in-word; Type:                  Text Objects.       (line   42)
* select-prompt, completion style; Keystroke: Standard Styles.
                                                             (line 1412)
* select-scroll, completion style; Keystroke: Standard Styles.
                                                             (line 1421)
* select-word-match; Type:               Widgets.            (line   28)
* select-word-style; Type:               Widgets.            (line   28)
* select; Function:                      Complex Commands.   (line   95)
* selection, case; Command:              Complex Commands.   (line   66)
* selection, user; Command:              Complex Commands.   (line   95)
* self-insert-unmeta; Type:              Modifying Text.     (line  254)
* self-insert; Type:                     Modifying Text.     (line  249)
* send-break; Type:                      Miscellaneous.      (line  256)
* send-invisible; Type:                  Widgets.            (line 1334)
* separate-sections, completion style; Keystroke: Standard Styles.
                                                             (line 1432)
* sequences, completion tag; Keystroke:  Standard Tags.      (line  299)
* sessions, completion tag; Keystroke:   Standard Tags.      (line  303)
* set-local-history; Type:               History Control.    (line  356)
* set-mark-command; Type:                Miscellaneous.      (line  306)
* set; Function:                         Shell Builtin Commands.
                                                             (line 1878)
* setcap; Function:                      The zsh/cap Module. (line   21)
* setopt; Function:                      Shell Builtin Commands.
                                                             (line 1932)
* sh compatibility; Command:             Compatibility.      (line    6)
* sh, compatibility; Command:            Shell Builtin Commands.
                                                             (line  588)
* sh, expansion style; Command:          Shell Emulation.    (line  270)
* sh, field splitting style, parameter; Command: Parameter Expansion.
                                                             (line  352)
* sh, field splitting style; Command:    Shell Emulation.    (line  289)
* sh, globbing style; Command:           Expansion and Globbing.
                                                             (line  232)
* sh, redirections with no command; Command: Shell Emulation.
                                                             (line  278)
* sh, single letter options style; Command: Shell Emulation. (line  283)
* share history; Command:                History.            (line  168)
* SHAREHISTORY; Program:                 History.            (line  168)
* SHARE_HISTORY; Program:                History.            (line  168)
* shell flags; Command:                  Invocation<2>.      (line    6)
* shell grammar; Command:                Shell Grammar.      (line    6)
* shell options; Command:                Invocation<2>.      (line    6)
* shell, cloning; Command:               The zsh/clone Module.
                                                             (line    8)
* shell, suspending; Command:            Shell Builtin Commands.
                                                             (line 1980)
* shell, timing; Command:                Shell Builtin Commands.
                                                             (line 2008)
* SHFILEEXPANSION; Program:              Shell Emulation.    (line  270)
* SHGLOB; Program:                       Expansion and Globbing.
                                                             (line  232)
* shift; Function:                       Shell Builtin Commands.
                                                             (line 1961)
* SHINSTDIN; Program:                    Shell State<2>.     (line   50)
* SHIN_STDIN; Program:                   Shell State<2>.     (line   50)
* SHLVL; Variable:                       Parameters Set by the Shell.
                                                             (line  262)
* SHNULLCMD; Program:                    Shell Emulation.    (line  278)
* SHOPTIONLETTERS; Program:              Shell Emulation.    (line  283)
* SHORTLOOPS; Program:                   Input/Output.       (line  163)
* SHORTREPEAT; Program:                  Input/Output.       (line  168)
* SHORT_LOOPS; Program:                  Input/Output.       (line  163)
* SHORT_REPEAT; Program:                 Input/Output.       (line  168)
* show-ambiguity, completion style; Keystroke: Standard Styles.
                                                             (line 1446)
* show-completer, completion style; Keystroke: Standard Styles.
                                                             (line 1455)
* show-prog; Keystroke:                  Styles.             (line   49)
* shutdown files; Command:               Startup/Shutdown Files.
                                                             (line    6)
* SHWORDSPLIT; Program:                  Shell Emulation.    (line  289)
* SH_FILE_EXPANSION; Program:            Shell Emulation.    (line  270)
* SH_GLOB; Program:                      Expansion and Globbing.
                                                             (line  232)
* SH_NULLCMD, use of; Program:           Redirections with no command.
                                                             (line   14)
* SH_NULLCMD; Program:                   Shell Emulation.    (line  278)
* SH_OPTION_LETTERS; Program:            Shell Emulation.    (line  283)
* SH_WORD_SPLIT, toggle; Program:        Parameter Expansion.
                                                             (line  352)
* SH_WORD_SPLIT; Program:                Shell Emulation.    (line  289)
* signals, completion tag; Keystroke:    Standard Tags.      (line  307)
* signals, trapping; Command:            Trap Functions.     (line   11)
* signals, trapping; Command <1>:        Shell Builtin Commands.
                                                             (line 2013)
* signals; Variable:                     Parameters Set by the Shell.
                                                             (line  266)
* simple commands; Command:              Simple Commands & Pipelines.
                                                             (line    6)
* single command; Command:               Shell State<2>.     (line   65)
* single letter options, ksh style; Command: Shell Emulation.
                                                             (line  283)
* single letter options; Command:        Single Letter Options.
                                                             (line    6)
* single-ignored, completion style; Keystroke: Standard Styles.
                                                             (line 1463)
* SINGLECOMMAND; Program:                Shell State<2>.     (line   65)
* SINGLELINEZLE; Program:                Zle.                (line   40)
* SINGLE_COMMAND; Program:               Shell State<2>.     (line   65)
* SINGLE_LINE_ZLE; Program:              Zle.                (line   40)
* slash, removing trailing; Command:     Completion<2>.      (line   53)
* slow connection, editing over; Command: Parameters Used by the Shell.
                                                             (line   26)
* smart-insert-last-word; Type:          Widgets.            (line 1354)
* sockets, closing TCP; Command:         Closing Connections.
                                                             (line    6)
* sockets, inbound TCP; Command:         Inbound Connections<2>.
                                                             (line    6)
* sockets, inbound Unix domain; Command: Inbound Connections.
                                                             (line    6)
* sockets, outbound TCP; Command:        Outbound Connections<2>.
                                                             (line    6)
* sockets, outbound Unix domain; Command: Outbound Connections.
                                                             (line    6)
* sockets, TCP; Command:                 The zsh/net/tcp Module.
                                                             (line    8)
* sockets, Unix domain; Command:         The zsh/net/socket Module.
                                                             (line    8)
* sockets; Command:                      The zsh/net/socket Module.
                                                             (line    8)
* sort, completion style; Keystroke:     Standard Styles.    (line 1471)
* source; Function:                      Shell Builtin Commands.
                                                             (line 1971)
* SOURCETRACE; Program:                  Scripts and Functions.
                                                             (line  227)
* SOURCE_TRACE; Program:                 Scripts and Functions.
                                                             (line  227)
* special characters, highlighting; Command: Character Highlighting.
                                                             (line   41)
* special parameters; Command:           Description<2>.     (line   33)
* special-dirs, completion style; Keystroke: Standard Styles.
                                                             (line 1496)
* spell-word; Type:                      Miscellaneous.      (line  313)
* spelling correction; Command:          Input/Output.       (line   31)
* split-shell-arguments; Type:           Utility Functions<2>.
                                                             (line   10)
* split-undo; Type:                      Miscellaneous.      (line  317)
* SPROMPT; Variable:                     Parameters Used by the Shell.
                                                             (line  462)
* squeeze-slashes, completion style; Keystroke: Standard Styles.
                                                             (line 1510)
* SRANDOM; Variable:                     Parameters<3>.      (line    6)
* stack, history; Command:               Shell Builtin Commands.
                                                             (line  875)
* stagedstr; Keystroke:                  Configuration<4>.   (line  211)
* startup files, global, inhibiting; Command: Initialisation.
                                                             (line   26)
* startup files, sourcing; Command:      Initialisation.     (line   33)
* startup files; Command:                Startup/Shutdown Files.
                                                             (line    6)
* stat; Function:                        The zsh/stat Module.
                                                             (line    9)
* static named directories; Command:     Static Named Directories.
                                                             (line    6)
* status, on exit from pipeline; Command: Scripts and Functions.
                                                             (line  218)
* status; Variable:                      Parameters Set by the Shell.
                                                             (line   82)
* STDIN; Program:                        Option Aliases.     (line   50)
* stop, completion style; Keystroke:     Standard Styles.    (line 1518)
* stop-keys, widget style; Keystroke:    Styles<2>.          (line  140)
* strftime; Function:                    The zsh/datetime Module.
                                                             (line    8)
* strings, completion tag; Keystroke:    Standard Tags.      (line  311)
* strip-comments, completion style; Keystroke: Standard Styles.
                                                             (line 1527)
* STTY; Variable:                        Parameters Used by the Shell.
                                                             (line  491)
* styles in zftp functions; Command:     Configuration.      (line    6)
* styles, completion tag; Keystroke:     Standard Tags.      (line  316)
* sublist; Command:                      Simple Commands & Pipelines.
                                                             (line   44)
* subscript flags; Command:              Subscript Flags.    (line    6)
* subscripts; Command:                   Array Subscripts.   (line    6)
* subshell; Command:                     Complex Commands.   (line  112)
* subst-globs-only, completion style; Keystroke: Standard Styles.
                                                             (line 1534)
* substitute, completion style; Keystroke: Standard Styles.  (line 1544)
* substitution, command, current shell; Command: Command Substitution.
                                                             (line   35)
* substitution, command, non forking; Command: Command Substitution.
                                                             (line   35)
* substitution, command; Command:        Command Substitution.
                                                             (line    6)
* substitution, nofork; Command:         Command Substitution.
                                                             (line   35)
* substitution, parameter, flags; Command: Parameter Expansion Flags.
                                                             (line    6)
* substitution, parameter, rules; Command: Rules.            (line    6)
* substitution, process; Command:        Process Substitution.
                                                             (line    6)
* suffix, completion style; Keystroke:   Standard Styles.    (line 1552)
* suffix, highlighting removable, in completion; Command: Character Highlighting.
                                                             (line   47)
* SUFFIX; Variable:                      Completion Special Parameters.
                                                             (line   66)
* suffixes, completion tag; Keystroke:   Standard Tags.      (line  320)
* SUFFIX_ACTIVE; Variable:               User-Defined Widgets.
                                                             (line  287)
* SUFFIX_END; Variable:                  User-Defined Widgets.
                                                             (line  287)
* SUFFIX_START; Variable:                User-Defined Widgets.
                                                             (line  287)
* sum; Function:                         Mathematical Functions.
                                                             (line  242)
* sun keyboard, annoying; Command:       Input/Output.       (line  173)
* SUNKEYBOARDHACK; Program:              Input/Output.       (line  173)
* SUN_KEYBOARD_HACK; Program:            Input/Output.       (line  173)
* suspend; Function:                     Shell Builtin Commands.
                                                             (line 1980)
* suspending jobs; Command:              Jobs.               (line   26)
* suspending the shell; Command:         Shell Builtin Commands.
                                                             (line 1980)
* symbolic links; Command:               Changing Directories.
                                                             (line   53)
* sync; Function:                        The zsh/files Module.
                                                             (line  195)
* syserror; Function:                    Builtins.           (line    6)
* sysopen; Function:                     Builtins.           (line   27)
* sysparams; Variable:                   Parameters<4>.      (line   18)
* sysread; Function:                     Builtins.           (line   95)
* tag-order, completion style; Keystroke: Standard Styles.   (line 1561)
* tags, completion tag; Keystroke:       Standard Tags.      (line  324)
* targets, completion tag; Keystroke:    Standard Tags.      (line  328)
* TCP function system; Command:          TCP Function System.
                                                             (line    6)
* TCP, example; Command:                 Example<2>.         (line    6)
* TCP; Command:                          The zsh/net/tcp Module.
                                                             (line    8)
* tcp_alias; Function:                   Session Management. (line    6)
* tcp_aliases; Function:                 TCP Utility Parameters.
                                                             (line    9)
* tcp_by_fd; Function:                   TCP Utility Parameters.
                                                             (line   15)
* tcp_by_name; Function:                 TCP Utility Parameters.
                                                             (line   20)
* tcp_close; Function:                   Basic I/O.          (line   82)
* tcp_command; Function:                 Advanced I/O.       (line    6)
* tcp_expect; Function:                  Advanced I/O.       (line   19)
* tcp_expect_lines; Variable:            TCP User Parameters.
                                                             (line   21)
* tcp_fd_handler; Function:              TCP Utility Functions.
                                                             (line    9)
* tcp_filter; Variable:                  TCP User Parameters.
                                                             (line   26)
* TCP_HANDLER_ACTIVE; Variable:          TCP User Parameters.
                                                             (line   34)
* TCP_LINE; Variable:                    TCP User Parameters.
                                                             (line   40)
* tcp_lines; Variable:                   TCP User Parameters.
                                                             (line   50)
* TCP_LINE_FD; Variable:                 TCP User Parameters.
                                                             (line   44)
* tcp_log; Function:                     Session Management. (line   27)
* TCP_LOG; Variable:                     TCP User Parameters.
                                                             (line   55)
* TCP_LOG_SESS; Function:                TCP User Parameters.
                                                             (line   62)
* tcp_no_spam_list; Variable:            TCP User Parameters.
                                                             (line   71)
* tcp_on_alias; Function:                TCP User-defined Functions.
                                                             (line   15)
* tcp_on_awol; Function:                 TCP User-defined Functions.
                                                             (line   21)
* tcp_on_close; Function:                TCP User-defined Functions.
                                                             (line   42)
* tcp_on_open; Function:                 TCP User-defined Functions.
                                                             (line   48)
* tcp_on_read; Variable:                 TCP User-defined Parameters.
                                                             (line    9)
* tcp_on_rename; Function:               TCP User-defined Functions.
                                                             (line   56)
* tcp_on_spam; Function:                 TCP User-defined Functions.
                                                             (line   61)
* tcp_on_unalias; Function:              TCP User-defined Functions.
                                                             (line   80)
* tcp_open; Function:                    Basic I/O.          (line    6)
* tcp_output; Function:                  TCP Utility Functions.
                                                             (line   21)
* TCP_OUTPUT; Variable:                  TCP User Parameters.
                                                             (line   75)
* TCP_PROMPT; Variable:                  TCP User Parameters.
                                                             (line   83)
* tcp_proxy; Function:                   Advanced I/O.       (line   75)
* tcp_read; Function:                    Basic I/O.          (line  103)
* TCP_READ_DEBUG; Variable:              TCP User Parameters.
                                                             (line   99)
* tcp_rename; Function:                  Session Management. (line   52)
* TCP_SECONDS_START; Variable:           TCP User Parameters.
                                                             (line  104)
* tcp_send; Function:                    Basic I/O.          (line  154)
* tcp_sess; Function:                    Session Management. (line   56)
* TCP_SESS; Variable:                    TCP User Parameters.
                                                             (line  123)
* TCP_SILENT; Variable:                  TCP User Parameters.
                                                             (line  128)
* tcp_spam; Function:                    Advanced I/O.       (line   96)
* tcp_spam_list; Variable:               TCP User Parameters.
                                                             (line  134)
* tcp_talk; Function:                    Advanced I/O.       (line  126)
* TCP_TALK_ESCAPE; Variable:             TCP User Parameters.
                                                             (line  139)
* TCP_TIMEOUT; Variable:                 TCP User Parameters.
                                                             (line  144)
* tcp_wait; Function:                    Advanced I/O.       (line  145)
* TERM; Variable:                        Parameters Used by the Shell.
                                                             (line  513)
* termcap value, printing; Command:      The zsh/termcap Module.
                                                             (line    8)
* termcap; Variable:                     The zsh/termcap Module.
                                                             (line   15)
* terminal escape sequences for highlighting; Command: Character Highlighting.
                                                             (line   78)
* terminal; Command:                     The zsh/clone Module.
                                                             (line    8)
* terminfo value, printing; Command:     The zsh/terminfo Module.
                                                             (line    8)
* TERMINFO; Variable:                    Parameters Used by the Shell.
                                                             (line  522)
* terminfo; Variable:                    The zsh/terminfo Module.
                                                             (line   15)
* TERMINFO_DIRS; Variable:               Parameters Used by the Shell.
                                                             (line  529)
* test; Function:                        Shell Builtin Commands.
                                                             (line 1986)
* text objects; Command:                 Text Objects.       (line    6)
* throw; Function:                       Exception Handling. (line    9)
* time-zones, completion tag; Keystroke: Standard Tags.      (line  332)
* time; Function:                        Complex Commands.   (line  216)
* timed execution; Command:              The zsh/sched Module.
                                                             (line    9)
* TIMEFMT; Variable:                     Parameters Used by the Shell.
                                                             (line  551)
* times; Function:                       Shell Builtin Commands.
                                                             (line 2008)
* timing the shell; Command:             Shell Builtin Commands.
                                                             (line 2008)
* timing; Command:                       Complex Commands.   (line  216)
* titlebar, zftp style; Keystroke:       Configuration.      (line   53)
* TMOUT; Variable:                       Parameters Used by the Shell.
                                                             (line  651)
* TMPPREFIX; Variable:                   Parameters Used by the Shell.
                                                             (line  662)
* TMPSUFFIX; Variable:                   Parameters Used by the Shell.
                                                             (line  668)
* toggle, widget style; Keystroke:       Styles<2>.          (line  148)
* to_end, compstate; Variable:           Completion Special Parameters.
                                                             (line  359)
* tracing, of commands; Command:         Scripts and Functions.
                                                             (line  256)
* tracing, of input lines; Command:      Scripts and Functions.
                                                             (line  252)
* TRACKALL; Program:                     Option Aliases.     (line   54)
* TRACK_ALL; Program:                    Option Aliases.     (line   54)
* TRANSIENTRPROMPT; Program:             Prompting.          (line   47)
* TRANSIENT_RPROMPT; Program:            Prompting.          (line   47)
* transpose-chars; Type:                 Modifying Text.     (line  267)
* transpose-lines; Type:                 Widgets.            (line 1386)
* transpose-words-match; Type:           Widgets.            (line   28)
* transpose-words; Type:                 Modifying Text.     (line  273)
* trap, use of; Function:                Trap Functions.     (line   61)
* trap; Function:                        Shell Builtin Commands.
                                                             (line 2013)
* TRAPDEBUG; Function:                   Trap Functions.     (line   37)
* TRAPERR; Function:                     Trap Functions.     (line   52)
* TRAPEXIT; Function:                    Trap Functions.     (line   45)
* trapping signals; Command:             Trap Functions.     (line   11)
* trapping signals; Command <1>:         Shell Builtin Commands.
                                                             (line 2013)
* traps, asynchronous; Command:          Shell Emulation.    (line  295)
* traps, DEBUG, before or after command; Command: Scripts and Functions.
                                                             (line   49)
* traps, on function exit; Command:      Shell Emulation.    (line  254)
* traps, POSIX compatibility; Command:   Shell Emulation.    (line  254)
* TRAPSASYNC; Program:                   Shell Emulation.    (line  295)
* TRAPS_ASYNC; Program:                  Shell Emulation.    (line  295)
* TRAPZERR; Function:                    Trap Functions.     (line   52)
* true; Function:                        Shell Builtin Commands.
                                                             (line 2086)
* try blocks; Command:                   Complex Commands.   (line  123)
* TRY_BLOCK_ERROR; Variable:             Parameters Set by the Shell.
                                                             (line  322)
* TRY_BLOCK_INTERRUPT; Variable:         Parameters Set by the Shell.
                                                             (line  329)
* tty, freezing; Command:                Shell Builtin Commands.
                                                             (line 2090)
* TTY; Variable:                         Parameters Set by the Shell.
                                                             (line  340)
* ttyctl; Function:                      Shell Builtin Commands.
                                                             (line 2090)
* TTYIDLE; Variable:                     Parameters Set by the Shell.
                                                             (line  344)
* type; Function:                        Shell Builtin Commands.
                                                             (line 2112)
* types, completion tag; Keystroke:      Standard Tags.      (line  336)
* typeset; Function:                     Shell Builtin Commands.
                                                             (line 2116)
* TYPESETSILENT; Program:                Scripts and Functions.
                                                             (line  236)
* TYPESETTOUNSET; Program:               Scripts and Functions.
                                                             (line  245)
* TYPESET_SILENT; Program:               Scripts and Functions.
                                                             (line  236)
* TYPESET_TO_UNSET; Program:             Scripts and Functions.
                                                             (line  245)
* UID; Variable:                         Parameters Set by the Shell.
                                                             (line  349)
* ulimit; Function:                      Shell Builtin Commands.
                                                             (line 2589)
* umask; Command:                        Shell Builtin Commands.
                                                             (line 2722)
* umask; Function:                       Shell Builtin Commands.
                                                             (line 2722)
* unalias; Function:                     Shell Builtin Commands.
                                                             (line 2732)
* unambiguous, compstate; Variable:      Completion Special Parameters.
                                                             (line  375)
* unambiguous_cursor, compstate; Variable: Completion Special Parameters.
                                                             (line  381)
* unambiguous_positions, compstate; Variable: Completion Special Parameters.
                                                             (line  388)
* undefined-key; Type:                   Miscellaneous.      (line  324)
* undo; Type:                            Miscellaneous.      (line  329)
* UNDO_CHANGE_NO; Variable:              User-Defined Widgets.
                                                             (line  300)
* UNDO_LIMIT_NO; Variable:               User-Defined Widgets.
                                                             (line  306)
* unfunction; Function:                  Shell Builtin Commands.
                                                             (line 2742)
* unhash; Function:                      Shell Builtin Commands.
                                                             (line 2746)
* Unicode combining characters; Command: Zle.                (line   10)
* universal-argument; Type:              Arguments.          (line   19)
* unlimit; Function:                     Shell Builtin Commands.
                                                             (line 2760)
* unset parameters, substituting; Command: Expansion and Globbing.
                                                             (line  243)
* unset; Function:                       Shell Builtin Commands.
                                                             (line 2772)
* UNSET; Program:                        Expansion and Globbing.
                                                             (line  243)
* unsetopt; Function:                    Shell Builtin Commands.
                                                             (line 2797)
* unstagedstr; Keystroke:                Configuration<4>.   (line  216)
* until loops; Command:                  Complex Commands.   (line   52)
* until; Function:                       Complex Commands.   (line   52)
* up-case-word-match; Type:              Widgets.            (line   28)
* up-case-word; Type:                    Modifying Text.     (line  297)
* up-history; Type:                      History Control.    (line  346)
* up-line-or-beginning-search; Type:     Widgets.            (line  468)
* up-line-or-history; Type:              History Control.    (line  325)
* up-line-or-search; Type:               History Control.    (line  336)
* up-line; Type:                         Movement.           (line  144)
* update, zftp style; Keystroke:         Configuration.      (line   37)
* url-quote-magic; Type:                 Widgets.            (line 1403)
* urls, completion style; Keystroke:     Standard Styles.    (line 1710)
* urls, completion tag; Keystroke:       Standard Tags.      (line  340)
* use-cache, completion style; Keystroke: Standard Styles.   (line 1744)
* use-compctl, completion style; Keystroke: Standard Styles. (line 1752)
* use-ip, completion style; Keystroke:   Standard Styles.    (line 1773)
* use-prompt-escapes; Keystroke:         Configuration<4>.   (line  298)
* use-quilt; Keystroke:                  Configuration<4>.   (line  142)
* use-server; Keystroke:                 Configuration<4>.   (line  242)
* use-simple; Keystroke:                 Configuration<4>.   (line  262)
* user contributions; Command:           User Contributions. (line    6)
* user selection; Command:               Complex Commands.   (line   95)
* userdirs; Variable:                    The zsh/parameter Module.
                                                             (line  212)
* usergroups; Variable:                  The zsh/parameter Module.
                                                             (line  217)
* USERNAME; Variable:                    Parameters Set by the Shell.
                                                             (line  360)
* users, completion style; Keystroke:    Standard Styles.    (line 1783)
* users, completion tag; Keystroke:      Standard Tags.      (line  344)
* users, watching; Command:              The zsh/watch Module.
                                                             (line  148)
* users-hosts, completion style; Keystroke: Standard Styles. (line 1790)
* users-hosts-ports, completion style; Keystroke: Standard Styles.
                                                             (line 1805)
* values, completion tag; Keystroke:     Standard Tags.      (line  348)
* vared, compstate; Variable:            Completion Special Parameters.
                                                             (line  396)
* vared; Function:                       Zle Builtins.       (line  244)
* variables, environment; Command:       Description<2>.     (line   24)
* variables; Command:                    Parameters.         (line    6)
* variant, completion tag; Keystroke:    Standard Tags.      (line  352)
* vcs_info; Function:                    Function Descriptions Public API.
                                                             (line    6)
* vcs_info_hookadd; Function:            Function Descriptions Public API.
                                                             (line   18)
* vcs_info_hookdel; Function:            Function Descriptions Public API.
                                                             (line   31)
* vcs_info_lastmsg; Function:            Function Descriptions Public API.
                                                             (line   47)
* vcs_info_printsys; Function:           Function Descriptions Public API.
                                                             (line   54)
* vcs_info_setsys; Function:             Function Descriptions Public API.
                                                             (line   60)
* VENDOR; Variable:                      Parameters Set by the Shell.
                                                             (line  370)
* verbose, completion style; Keystroke:  Standard Styles.    (line 1810)
* verbose, widget style; Keystroke:      Styles<2>.          (line  158)
* VERBOSE; Program:                      Scripts and Functions.
                                                             (line  252)
* version control utility; Command:      Gathering information from version control systems.
                                                             (line    6)
* vi-add-eol; Type:                      Modifying Text.     (line    6)
* vi-add-next; Type:                     Modifying Text.     (line   10)
* vi-backward-blank-word-end; Type:      Movement.           (line   11)
* vi-backward-blank-word; Type:          Movement.           (line    6)
* vi-backward-char; Type:                Movement.           (line   20)
* vi-backward-delete-char; Type:         Modifying Text.     (line   19)
* vi-backward-kill-word; Type:           Modifying Text.     (line   37)
* vi-backward-word-end; Type:            Movement.           (line   36)
* vi-backward-word; Type:                Movement.           (line   32)
* vi-beginning-of-line; Type:            Movement.           (line   45)
* vi-caps-lock-panic; Type:              Miscellaneous.      (line   76)
* vi-change-eol; Type:                   Modifying Text.     (line   59)
* vi-change-whole-line; Type:            Modifying Text.     (line   63)
* vi-change; Type:                       Modifying Text.     (line   46)
* vi-cmd-mode; Type:                     Miscellaneous.      (line   71)
* vi-delete-char; Type:                  Modifying Text.     (line   96)
* vi-delete; Type:                       Modifying Text.     (line   86)
* vi-digit-or-beginning-of-line; Type:   Miscellaneous.      (line  385)
* vi-down-case; Type:                    Modifying Text.     (line  109)
* vi-down-line-or-history; Type:         History Control.    (line   25)
* vi-end-of-line; Type:                  Movement.           (line   58)
* vi-fetch-history; Type:                History Control.    (line   65)
* vi-find-next-char-skip; Type:          Movement.           (line   88)
* vi-find-next-char; Type:               Movement.           (line   83)
* vi-find-prev-char-skip; Type:          Movement.           (line   98)
* vi-find-prev-char; Type:               Movement.           (line   93)
* vi-first-non-blank; Type:              Movement.           (line  103)
* vi-forward-blank-word-end; Type:       Movement.           (line   69)
* vi-forward-blank-word; Type:           Movement.           (line   64)
* vi-forward-char; Type:                 Movement.           (line   79)
* vi-forward-word-end; Type:             Movement.           (line  120)
* vi-forward-word; Type:                 Movement.           (line  107)
* vi-goto-column; Type:                  Movement.           (line  124)
* vi-goto-mark-line; Type:               Movement.           (line  132)
* vi-goto-mark; Type:                    Movement.           (line  128)
* vi-history-search-backward; Type:      History Control.    (line  228)
* vi-history-search-forward; Type:       History Control.    (line  261)
* vi-indent; Type:                       Modifying Text.     (line  124)
* vi-insert-bol; Type:                   Modifying Text.     (line  132)
* vi-insert; Type:                       Modifying Text.     (line  128)
* vi-join; Type:                         Modifying Text.     (line  137)
* vi-kill-eol; Type:                     Modifying Text.     (line  150)
* vi-kill-line; Type:                    Modifying Text.     (line  146)
* vi-match-bracket; Type:                Modifying Text.     (line  166)
* vi-open-line-above; Type:              Modifying Text.     (line  173)
* vi-open-line-below; Type:              Modifying Text.     (line  177)
* vi-oper-swap-case; Type:               Modifying Text.     (line  181)
* vi-pipe; Type:                         Widgets.            (line 1476)
* vi-pound-insert; Type:                 Miscellaneous.      (line  156)
* vi-put-after; Type:                    Modifying Text.     (line  198)
* vi-put-before; Type:                   Modifying Text.     (line  192)
* vi-quoted-insert; Type:                Modifying Text.     (line  216)
* vi-repeat-change; Type:                Modifying Text.     (line  236)
* vi-repeat-find; Type:                  Movement.           (line  136)
* vi-repeat-search; Type:                History Control.    (line  317)
* vi-replace-chars; Type:                Modifying Text.     (line  244)
* vi-replace; Type:                      Modifying Text.     (line  232)
* vi-rev-repeat-find; Type:              Movement.           (line  140)
* vi-rev-repeat-search; Type:            History Control.    (line  321)
* vi-set-buffer; Type:                   Miscellaneous.      (line  271)
* vi-set-mark; Type:                     Miscellaneous.      (line  302)
* vi-substitute; Type:                   Modifying Text.     (line  259)
* vi-swap-case; Type:                    Modifying Text.     (line  263)
* vi-undo-change; Type:                  Miscellaneous.      (line  346)
* vi-unindent; Type:                     Modifying Text.     (line  286)
* vi-up-case; Type:                      Modifying Text.     (line  290)
* vi-up-line-or-history; Type:           History Control.    (line  330)
* vi-yank-eol; Type:                     Modifying Text.     (line  321)
* vi-yank-whole-line; Type:              Modifying Text.     (line  317)
* vi-yank; Type:                         Modifying Text.     (line  311)
* VI; Program:                           Zle.                (line   50)
* visual-line-mode; Type:                Miscellaneous.      (line  358)
* visual-mode; Type:                     Miscellaneous.      (line  351)
* VISUAL; Variable:                      Keymaps.            (line   54)
* visuals, completion tag; Keystroke:    Standard Tags.      (line  358)
* wait; Function:                        Shell Builtin Commands.
                                                             (line 2810)
* waiting before rm *; Command:          Input/Output.       (line  155)
* waiting for jobs; Command:             Shell Builtin Commands.
                                                             (line 2810)
* warn-time; Keystroke:                  Styles.             (line   59)
* WARNCREATEGLOBAL; Program:             Expansion and Globbing.
                                                             (line  250)
* warnings, completion tag; Keystroke:   Standard Tags.      (line  362)
* WARNNESTEDVAR; Program:                Expansion and Globbing.
                                                             (line  260)
* WARN_CREATE_GLOBAL; Program:           Expansion and Globbing.
                                                             (line  250)
* WARN_NESTED_VAR; Program:              Expansion and Globbing.
                                                             (line  260)
* watch, use of; Variable:               The zsh/watch Module.
                                                             (line  148)
* watch; Variable:                       The zsh/watch Module.
                                                             (line   14)
* WATCH; Variable:                       The zsh/watch Module.
                                                             (line   14)
* WATCHFMT; Variable:                    The zsh/watch Module.
                                                             (line   37)
* watching users; Command:               The zsh/watch Module.
                                                             (line  148)
* weather, example function; Function:   The zsh/zutil Module.
                                                             (line   44)
* what-cursor-position; Type:            Miscellaneous.      (line  365)
* whence; Function:                      Shell Builtin Commands.
                                                             (line 2837)
* where-is; Type:                        Miscellaneous.      (line  371)
* where; Function:                       Shell Builtin Commands.
                                                             (line 2915)
* which-command; Type:                   Miscellaneous.      (line  379)
* which-command; Type <1>:               Widgets.            (line 1487)
* which; Function:                       Shell Builtin Commands.
                                                             (line 2919)
* while loops; Command:                  Complex Commands.   (line   47)
* while; Function:                       Complex Commands.   (line   47)
* WIDGET, in hooks; Variable:            Manipulating Hook Functions.
                                                             (line   64)
* widget, widget style; Keystroke:       Styles<2>.          (line  167)
* WIDGET; Variable:                      User-Defined Widgets.
                                                             (line  324)
* WIDGETFUNC; Variable:                  User-Defined Widgets.
                                                             (line  328)
* widgets, binding; Command:             Zle Builtins.       (line  296)
* widgets, calling; Command:             Zle Builtins.       (line  296)
* widgets, completion tag; Keystroke:    Standard Tags.      (line  366)
* widgets, defining; Command:            Zle Builtins.       (line  296)
* widgets, invoking; Command:            Zle Builtins.       (line  296)
* widgets, rebinding; Command:           Zle Builtins.       (line  296)
* widgets, standard; Command:            Standard Widgets.   (line    6)
* widgets, user-defined; Command:        User-Defined Widgets.
                                                             (line    6)
* widgets; Command:                      Zle Widgets.        (line    6)
* widgets; Variable:                     The zsh/zleparameter Module.
                                                             (line   14)
* WIDGETSTYLE; Variable:                 User-Defined Widgets.
                                                             (line  337)
* windows, completion tag; Keystroke:    Standard Tags.      (line  370)
* windows, curses; Command:              Builtin.            (line    6)
* word designators, history; Command:    Word Designators.   (line    6)
* word, completion style; Keystroke:     Standard Styles.    (line 1816)
* WORDCHARS; Variable:                   Parameters Used by the Shell.
                                                             (line  677)
* words; Variable:                       Completion Special Parameters.
                                                             (line  403)
* writing modules; Command:              The zsh/example Module.
                                                             (line    8)
* XTRACE; Program:                       Scripts and Functions.
                                                             (line  256)
* yank-pop; Type:                        Modifying Text.     (line  305)
* yank; Type:                            Modifying Text.     (line  301)
* YANK_ACTIVE; Variable:                 User-Defined Widgets.
                                                             (line  345)
* YANK_END; Variable:                    User-Defined Widgets.
                                                             (line  345)
* YANK_START; Variable:                  User-Defined Widgets.
                                                             (line  345)
* zap-to-char; Type:                     The zsh/deltochar Module.
                                                             (line   15)
* zargs; Function:                       Descriptions.       (line  255)
* ZBEEP; Variable:                       Parameters Used by the Shell.
                                                             (line  682)
* zcalc-auto-insert; Type:               Widgets.            (line 1500)
* zcalc; Function:                       Mathematical Functions.
                                                             (line    6)
* zcompile; Function:                    Shell Builtin Commands.
                                                             (line 2923)
* zcp; Function:                         Descriptions.       (line  376)
* zcurses; Function:                     Builtin.            (line    6)
* zcurses_attrs; Variable:               Parameters<2>.      (line   21)
* ZCURSES_COLORS; Variable:              Parameters<2>.      (line    6)
* zcurses_colors; Variable:              Parameters<2>.      (line   26)
* ZCURSES_COLOR_PAIRS; Variable:         Parameters<2>.      (line   12)
* zcurses_keycodes; Variable:            Parameters<2>.      (line   31)
* zcurses_windows; Variable:             Parameters<2>.      (line   38)
* zdelattr; Function:                    The zsh/attr Module.
                                                             (line   21)
* ZDOTDIR, use of; Variable:             Startup/Shutdown Files.
                                                             (line    6)
* ZDOTDIR; Variable:                     Parameters Used by the Shell.
                                                             (line  693)
* zed-set-file-name; Function:           Descriptions.       (line  357)
* zed; Function:                         Descriptions.       (line  311)
* zfanon; Function:                      Opening a Connection.
                                                             (line   50)
* zfautocheck; Function:                 Other Functions.    (line   16)
* zfcd; Function:                        Directory Management.
                                                             (line    6)
* zfcd_match; Function:                  Other Functions.    (line   28)
* zfcget; Function:                      Retrieving Files.   (line   34)
* zfclose; Function:                     Closing the Connection.
                                                             (line    6)
* zfcput; Function:                      Sending Files.      (line   25)
* zfdir; Function:                       Directory Management.
                                                             (line   46)
* zffcache; Function:                    Other Functions.    (line   92)
* zfgcp; Function:                       Retrieving Files.   (line   46)
* zfget; Function:                       Retrieving Files.   (line   13)
* zfget_match; Function:                 Other Functions.    (line   38)
* zfgoto; Function:                      Bookmarks.          (line   27)
* zfhere; Function:                      Directory Management.
                                                             (line   39)
* zfinit; Function:                      Other Functions.    (line   10)
* zfls; Function:                        Directory Management.
                                                             (line   69)
* zfmark; Function:                      Bookmarks.          (line   14)
* zfopen; Function:                      Opening a Connection.
                                                             (line   21)
* zformat; Function:                     The zsh/zutil Module.
                                                             (line  176)
* zfparams; Function:                    Opening a Connection.
                                                             (line    6)
* zfpcp; Function:                       Sending Files.      (line   33)
* zfput; Function:                       Sending Files.      (line    6)
* zfrglob; Function:                     Other Functions.    (line   47)
* zfrtime; Function:                     Other Functions.    (line   54)
* zfsession; Function:                   Session Management<2>.
                                                             (line    6)
* zfstat; Function:                      Status Commands.    (line   13)
* zftp function system, automatic reopening; Command: Automatic and Temporary Reopening.
                                                             (line    6)
* zftp function system, configuration; Command: Configuration.
                                                             (line    6)
* zftp function system, remote globbing; Command: Remote Globbing.
                                                             (line    6)
* zftp function system, styles; Command: Configuration.      (line    6)
* zftp function system; Command:         Zftp Function System.
                                                             (line    6)
* zftp, functions; Command:              Functions<3>.       (line    6)
* zftp, parameters; Command:             Parameters<5>.      (line    6)
* zftp, problems; Command:               Problems.           (line    6)
* zftp, subcommands; Command:            Subcommands.        (line    6)
* zftp; Function:                        The zsh/zftp Module.
                                                             (line    8)
* ZFTP_ACCOUNT; Variable:                Parameters<5>.      (line   59)
* zftp_chpwd, specification; Function:   Functions<3>.       (line    6)
* zftp_chpwd, supplied version; Function: Other Functions.   (line   62)
* ZFTP_CODE; Variable:                   Parameters<5>.      (line   68)
* ZFTP_COUNT; Variable:                  Functions<3>.       (line   42)
* ZFTP_FILE; Variable:                   Functions<3>.       (line   25)
* ZFTP_HOST; Variable:                   Parameters<5>.      (line   23)
* ZFTP_IP; Variable:                     Parameters<5>.      (line   18)
* ZFTP_PORT; Variable:                   Parameters<5>.      (line   30)
* ZFTP_PREFS; Variable:                  Parameters<5>.      (line   85)
* zftp_progress, specification; Function: Functions<3>.      (line   13)
* zftp_progress, supplied version; Function: Other Functions.
                                                             (line   81)
* ZFTP_PWD; Variable:                    Parameters<5>.      (line   64)
* ZFTP_REPLY; Variable:                  Parameters<5>.      (line   74)
* ZFTP_SESSION; Variable:                Parameters<5>.      (line   80)
* ZFTP_SIZE; Variable:                   Functions<3>.       (line   33)
* ZFTP_SYSTEM; Variable:                 Parameters<5>.      (line   43)
* ZFTP_TMOUT; Variable:                  Parameters<5>.      (line    9)
* ZFTP_TRANSFER; Variable:               Functions<3>.       (line   29)
* ZFTP_TYPE; Variable:                   Parameters<5>.      (line   50)
* ZFTP_USER; Variable:                   Parameters<5>.      (line   55)
* ZFTP_VERBOSE; Variable:                Parameters<5>.      (line  115)
* zftransfer; Function:                  Session Management<2>.
                                                             (line   30)
* zftype; Function:                      Status Commands.    (line    6)
* zfuget; Function:                      Retrieving Files.   (line   22)
* zfuput; Function:                      Sending Files.      (line   18)
* zgdbmpath; Function:                   The zsh/db/gdbm Module.
                                                             (line   48)
* zgdbm_tied; Function:                  The zsh/db/gdbm Module.
                                                             (line   53)
* zgetattr; Function:                    The zsh/attr Module.
                                                             (line   10)
* zgetopt; Function:                     Descriptions.       (line  385)
* zkbd; Function:                        Keyboard Definition.
                                                             (line    6)
* zle, builtin commands; Command:        Zle Builtins.       (line    6)
* ZLE, use of; Program:                  Description<3>.     (line    6)
* zle-history-line-set; Type:            Special Widgets.    (line   54)
* zle-isearch-exit; Type:                Special Widgets.    (line   10)
* zle-isearch-update; Type:              Special Widgets.    (line   16)
* zle-keymap-select; Type:               Special Widgets.    (line   58)
* zle-line-finish; Type:                 Special Widgets.    (line   49)
* zle-line-init; Type:                   Special Widgets.    (line   37)
* zle-line-pre-redraw; Type:             Special Widgets.    (line   32)
* ZLE; Command:                          Zsh Line Editor.    (line    6)
* zle; Function:                         Zle Builtins.       (line  296)
* ZLE; Program:                          Zle.                (line   60)
* zle_bracketed_paste; Variable:         Parameters Used by the Shell.
                                                             (line  698)
* zle_cursorform, setting; Variable:     Cursor Shape and Color.
                                                             (line    6)
* zle_cursorform; Variable:              Parameters Used by the Shell.
                                                             (line  709)
* zle_highlight, setting; Variable:      Character Highlighting.
                                                             (line    6)
* zle_highlight, use of; Variable:       Description<3>.     (line   23)
* zle_highlight; Variable:               Parameters Used by the Shell.
                                                             (line  720)
* ZLE_LINE_ABORTED; Variable:            Parameters Used by the Shell.
                                                             (line  725)
* ZLE_RECURSIVE; Variable:               User-Defined Widgets.
                                                             (line  361)
* ZLE_REMOVE_SUFFIX_CHARS; Variable:     Parameters Used by the Shell.
                                                             (line  732)
* ZLE_RPROMPT_INDENT; Variable:          Parameters Used by the Shell.
                                                             (line  774)
* ZLE_SPACE_SUFFIX_CHARS; Variable:      Parameters Used by the Shell.
                                                             (line  732)
* ZLE_STATE; Variable:                   User-Defined Widgets.
                                                             (line  368)
* zlistattr; Function:                   The zsh/attr Module.
                                                             (line   26)
* zln; Function:                         Descriptions.       (line  376)
* zlogout; Command:                      Startup/Shutdown Files.
                                                             (line   27)
* ZLS_COLORS; Variable:                  Colored Completion Listings.
                                                             (line   12)
* ZLS_COLOURS; Variable:                 Colored Completion Listings.
                                                             (line   12)
* zmathfunc; Function:                   Mathematical Functions.
                                                             (line  242)
* zmathfuncdef; Function:                Mathematical Functions.
                                                             (line  258)
* zmath_cube; Function:                  Shell Builtin Commands.
                                                             (line  994)
* zmodload; Function:                    Shell Builtin Commands.
                                                             (line 3066)
* zmv; Function:                         Descriptions.       (line  472)
* zparseopts; Function:                  The zsh/zutil Module.
                                                             (line  293)
* zprof; Function:                       The zsh/zprof Module.
                                                             (line   11)
* zprofile; Command:                     Startup/Shutdown Files.
                                                             (line   18)
* zpty; Function:                        The zsh/zpty Module.
                                                             (line    8)
* zrecompile utility; Command:           Recompiling Functions.
                                                             (line    6)
* zrecompile; Function:                  Recompiling Functions.
                                                             (line   18)
* zregexparse; Function:                 The zsh/zutil Module.
                                                             (line  289)
* zselect; Function:                     The zsh/zselect Module.
                                                             (line    8)
* zsetattr; Function:                    The zsh/attr Module.
                                                             (line   16)
* zsh-mime-handler; Function:            MIME Functions.     (line   10)
* zsh-mime-setup; Function:              MIME Functions.     (line   10)
* zsh-options, completion tag; Keystroke: Standard Tags.     (line  374)
* zsh/datetime, function system based on; Command: Calendar Function System.
                                                             (line    6)
* zshaddhistory; Function:               Hook Functions.     (line   53)
* zshaddhistory_functions; Variable:     Hook Functions.     (line   53)
* zshenv; Command:                       Startup/Shutdown Files.
                                                             (line    6)
* zshexit; Function:                     Hook Functions.     (line   89)
* zshexit_functions; Variable:           Hook Functions.     (line   89)
* ZSH_ARGZERO; Variable:                 Parameters Set by the Shell.
                                                             (line  501)
* zsh_directory_name_generic; Function:  Details of Directory Handling.
                                                             (line   24)
* zsh_eval_context; Variable:            Parameters Set by the Shell.
                                                             (line  374)
* ZSH_EVAL_CONTEXT; Variable:            Parameters Set by the Shell.
                                                             (line  374)
* ZSH_EXECUTION_STRING; Variable:        Parameters Set by the Shell.
                                                             (line  508)
* ZSH_EXEPATH; Variable:                 Parameters Set by the Shell.
                                                             (line  513)
* ZSH_NAME; Variable:                    Parameters Set by the Shell.
                                                             (line  521)
* ZSH_PATCHLEVEL; Variable:              Parameters Set by the Shell.
                                                             (line  526)
* zsh_scheduled_events; Variable:        The zsh/sched Module.
                                                             (line   50)
* ZSH_SCRIPT; Variable:                  Parameters Set by the Shell.
                                                             (line  538)
* ZSH_SUBSHELL <S>; Variable:            Parameters Set by the Shell.
                                                             (line  543)
* ZSH_VERSION; Variable:                 Parameters Set by the Shell.
                                                             (line  550)
* zsocket; Function:                     The zsh/net/socket Module.
                                                             (line    8)
* zstat; Function:                       The zsh/stat Module.
                                                             (line    9)
* zstyle+; Function:                     Descriptions.       (line  603)
* zstyle; Function:                      The zsh/zutil Module.
                                                             (line    8)
* ztcp, function system based on; Command: TCP Function System.
                                                             (line    6)
* ztcp; Function:                        The zsh/net/tcp Module.
                                                             (line    8)
* ztie; Function:                        The zsh/db/gdbm Module.
                                                             (line   15)
* zuntie; Function:                      The zsh/db/gdbm Module.
                                                             (line   37)

                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             
                                                             



Tag Table:
Node: Top330
Ref: manual doc553
Ref: 0553
Node: Introduction9798
Ref: Zsh/intro doc9875
Ref: 19875
Ref: Zsh/intro introduction9875
Ref: 29875
Ref: Zsh/intro the-z-shell-manual9875
Ref: 39875
Node: Author10547
Ref: Zsh/intro author10620
Ref: 410620
Node: Availability11009
Ref: Zsh/intro availability11104
Ref: 511104
Node: Mailing Lists11487
Ref: Zsh/intro mailing-lists11587
Ref: 611587
Node: The Zsh FAQ13169
Ref: Zsh/intro the-zsh-faq13273
Ref: 713273
Node: The Zsh Web Page13690
Ref: Zsh/intro the-zsh-web-page13798
Ref: 813798
Node: The Zsh Userguide13984
Ref: Zsh/intro the-zsh-userguide14089
Ref: 914089
Node: See Also14610
Ref: Zsh/intro see-also14690
Ref: a14690
Node: Roadmap14962
Ref: Zsh/roadmap doc15046
Ref: b15046
Ref: Zsh/roadmap roadmap15046
Ref: c15046
Node: When the shell starts15486
Ref: Zsh/roadmap when-the-shell-starts15572
Ref: d15572
Node: Interactive Use16193
Ref: Zsh/roadmap interactive-use16295
Ref: 1016295
Node: Completion18418
Ref: Zsh/roadmap completion18511
Ref: 1218511
Node: Extending the Line Editor19696
Ref: Zsh/roadmap extending-the-line-editor19789
Ref: 1319789
Node: Options20600
Ref: Zsh/roadmap options20697
Ref: 1520697
Node: Pattern Matching20955
Ref: Zsh/roadmap pattern-matching21063
Ref: 1621063
Node: General Comments on Syntax21915
Ref: Zsh/roadmap general-comments-on-syntax22027
Ref: 1822027
Node: Programming22757
Ref: Zsh/roadmap programming22844
Ref: 1c22844
Node: Invocation23861
Ref: Zsh/invoke doc23938
Ref: 1f23938
Ref: Zsh/invoke invocation23938
Ref: 2023938
Node: Invocation<2>24022
Ref: Zsh/invoke id124101
Ref: 2124101
Node: Compatibility28798
Ref: Zsh/invoke compatibility28877
Ref: 2228877
Node: Files31363
Ref: Zsh/files doc31446
Ref: 2331446
Ref: Zsh/files files31446
Ref: 2431446
Node: Startup/Shutdown Files31519
Ref: Zsh/files id131597
Ref: 2531597
Ref: Zsh/files startup-shutdown-files31597
Ref: e31597
Node: Files<2>34051
Ref: Zsh/files id234129
Ref: 2634129
Node: Shell Grammar34150
Ref: Zsh/grammar doc34234
Ref: 2734234
Ref: Zsh/grammar shell-grammar34234
Ref: 2834234
Node: Simple Commands & Pipelines34464
Ref: Zsh/grammar simple-commands-pipelines34567
Ref: 2934567
Node: Precommand Modifiers38377
Ref: Zsh/grammar precommand-modifiers38505
Ref: 2a38505
Node: Complex Commands40927
Ref: Zsh/grammar complex-commands41064
Ref: 2b41064
Node: Alternate Forms For Complex Commands51711
Ref: Zsh/grammar alternate-forms-for-complex-commands51842
Ref: 2d51842
Node: Reserved Words54626
Ref: Zsh/grammar reserved-words54747
Ref: 2e54747
Node: Errors55255
Ref: Zsh/grammar errors55348
Ref: 2f55348
Node: Comments57605
Ref: Zsh/grammar comments57692
Ref: 3057692
Node: Aliasing57997
Ref: Zsh/grammar aliasing58085
Ref: 3158085
Node: Alias Difficulties60484
Ref: Zsh/grammar alias-difficulties60544
Ref: 3260544
Node: Quoting62493
Ref: Zsh/grammar quoting62564
Ref: 3462564
Node: Redirection63655
Ref: Zsh/redirect doc63751
Ref: 3563751
Ref: Zsh/redirect redirection63751
Ref: 3663751
Node: Multios72206
Ref: Zsh/redirect id272295
Ref: 3972295
Ref: Zsh/redirect multios72295
Ref: 3a72295
Node: Redirections with no command76087
Ref: Zsh/redirect redirections-with-no-command76176
Ref: 3b76176
Node: Command Execution77316
Ref: Zsh/exec doc77408
Ref: 3c77408
Ref: Zsh/exec command-execution77408
Ref: 3d77408
Node: Functions79113
Ref: Zsh/func doc79208
Ref: 3e79208
Ref: Zsh/func functions79208
Ref: 3f79208
Node: Autoloading Functions81925
Ref: Zsh/func autoloading-functions82017
Ref: 4182017
Ref: Zsh/func id282017
Ref: 4282017
Node: Anonymous Functions87408
Ref: Zsh/func anonymous-functions87526
Ref: 4387526
Node: Special Functions89417
Ref: Zsh/func id389505
Ref: 4489505
Ref: Zsh/func special-functions89505
Ref: 4589505
Node: Hook Functions89665
Ref: Zsh/func hook-functions89753
Ref: 4689753
Node: Trap Functions94108
Ref: Zsh/func trap-functions94196
Ref: 4794196
Node: Jobs & Signals97499
Ref: Zsh/jobs doc97598
Ref: 4897598
Ref: Zsh/jobs jobs-signals97598
Ref: 4997598
Node: Jobs97664
Ref: Zsh/jobs jobs97732
Ref: 4a97732
Node: Signals102659
Ref: Zsh/jobs id1102727
Ref: 4b102727
Ref: Zsh/jobs signals102727
Ref: 4c102727
Node: Arithmetic Evaluation103542
Ref: Zsh/arith doc103655
Ref: 4e103655
Ref: Zsh/arith arithmetic-evaluation103655
Ref: 4f103655
Node: Conditional Expressions116292
Ref: Zsh/cond doc116407
Ref: 50116407
Ref: Zsh/cond conditional-expressions116407
Ref: 51116407
Node: Prompt Expansion125548
Ref: Zsh/prompt doc125651
Ref: 53125651
Ref: Zsh/prompt prompt-expansion125651
Ref: 54125651
Node: Expansion of Prompt Sequences125800
Ref: Zsh/prompt expansion-of-prompt-sequences125909
Ref: 55125909
Ref: Zsh/prompt id1125909
Ref: 56125909
Node: Simple Prompt Escapes127018
Ref: Zsh/prompt id2127169
Ref: 59127169
Ref: Zsh/prompt simple-prompt-escapes127169
Ref: 57127169
Node: Special Characters127332
Ref: Zsh/prompt special-characters127431
Ref: 5a127431
Node: Login Information127538
Ref: Zsh/prompt login-information127657
Ref: 5b127657
Node: Shell State128313
Ref: Zsh/prompt shell-state128427
Ref: 5c128427
Node: Date and Time132272
Ref: Zsh/prompt date-and-time132383
Ref: 5e132383
Node: Visual Effects134488
Ref: Zsh/prompt visual-effects134579
Ref: 5f134579
Node: Conditional Substrings in Prompts137374
Ref: Zsh/prompt conditional-substrings-in-prompts137487
Ref: 58137487
Ref: Zsh/prompt id3137487
Ref: 61137487
Node: Expansion143796
Ref: Zsh/expn doc143886
Ref: 62143886
Ref: Zsh/expn expansion143886
Ref: 63143886
Node: Description144127
Ref: Zsh/expn description144207
Ref: 64144207
Node: History Expansion145570
Ref: Zsh/expn history-expansion145679
Ref: 66145679
Node: Overview146558
Ref: Zsh/expn overview146643
Ref: 68146643
Node: Event Designators149436
Ref: Zsh/expn event-designators149546
Ref: 69149546
Node: Word Designators150982
Ref: Zsh/expn word-designators151093
Ref: 6a151093
Node: Modifiers152210
Ref: Zsh/expn modifiers152295
Ref: 6b152295
Node: Process Substitution162938
Ref: Zsh/expn process-substitution163055
Ref: 38163055
Node: Parameter Expansion168479
Ref: Zsh/expn parameter-expansion168599
Ref: 1a168599
Node: Parameter Expansion Flags187770
Ref: Zsh/expn id1187873
Ref: 6d187873
Ref: Zsh/expn parameter-expansion-flags187873
Ref: 6e187873
Node: Named References212043
Ref: Zsh/expn named-references212160
Ref: 70212160
Node: Rules216309
Ref: Zsh/expn rules216409
Ref: 72216409
Node: Examples226896
Ref: Zsh/expn examples226971
Ref: 73226971
Node: Command Substitution228918
Ref: Zsh/expn command-substitution229038
Ref: 74229038
Node: Arithmetic Expansion232148
Ref: Zsh/expn arithmetic-expansion232264
Ref: 75232264
Node: Brace Expansion232602
Ref: Zsh/expn brace-expansion232716
Ref: 77232716
Node: Filename Expansion235926
Ref: Zsh/expn filename-expansion236039
Ref: 5d236039
Node: Dynamic Named Directories237279
Ref: Zsh/expn dynamic-named-directories237389
Ref: 78237389
Node: Static Named Directories241162
Ref: Zsh/expn static-named-directories241296
Ref: 79241296
Node: `=’ Expansion242535
Ref: Zsh/expn id10242649
Ref: 7a242649
Node: Notes242923
Ref: Zsh/expn notes243004
Ref: 7b243004
Node: Filename Generation243753
Ref: Zsh/expn filename-generation243842
Ref: 17243842
Node: Glob Operators245263
Ref: Zsh/expn glob-operators245362
Ref: 7c245362
Ref: Zsh/expn id15245362
Ref: 7d245362
Node: ksh-like Glob Operators252483
Ref: Zsh/expn ksh-like-glob-operators252601
Ref: 7e252601
Node: Precedence253335
Ref: Zsh/expn precedence253453
Ref: 7f253453
Node: Globbing Flags254131
Ref: Zsh/expn globbing-flags254246
Ref: 80254246
Ref: Zsh/expn id28254246
Ref: 81254246
Node: Approximate Matching263518
Ref: Zsh/expn approximate-matching263641
Ref: 82263641
Ref: Zsh/expn id29263641
Ref: 83263641
Node: Recursive Globbing266582
Ref: Zsh/expn recursive-globbing266706
Ref: 84266706
Node: Glob Qualifiers267785
Ref: Zsh/expn glob-qualifiers267880
Ref: 85267880
Node: Parameters286292
Ref: Zsh/params doc286376
Ref: 86286376
Ref: Zsh/params parameters286376
Ref: 87286376
Node: Description<2>286620
Ref: Zsh/params description286703
Ref: 88286703
Node: Array Parameters290871
Ref: Zsh/params array-parameters290984
Ref: 1b290984
Node: Array Subscripts295643
Ref: Zsh/params array-subscripts295742
Ref: 8a295742
Ref: Zsh/params id1295742
Ref: 8b295742
Node: Array Element Assignment299750
Ref: Zsh/params array-element-assignment299873
Ref: 8c299873
Node: Subscript Flags301127
Ref: Zsh/params subscript-flags301251
Ref: 8d301251
Node: Subscript Parsing308170
Ref: Zsh/params subscript-parsing308261
Ref: 8e308261
Node: Positional Parameters314086
Ref: Zsh/params positional-parameters314201
Ref: 90314201
Node: Local Parameters315595
Ref: Zsh/params local-parameters315713
Ref: 40315713
Node: Named References<2>317244
Ref: Zsh/params named-references317368
Ref: 71317368
Node: Parameters Set by the Shell319277
Ref: Zsh/params parameters-set-by-the-shell319413
Ref: 93319413
Node: Parameters Used by the Shell338723
Ref: Zsh/params parameters-used-by-the-shell338831
Ref: 11338831
Node: Options<2>369021
Ref: Zsh/options doc369118
Ref: 9a369118
Ref: Zsh/options options369118
Ref: 9b369118
Node: Specifying Options369246
Ref: Zsh/options specifying-options369339
Ref: 52369339
Node: Description of Options371102
Ref: Zsh/options description-of-options371218
Ref: 9c371218
Node: Changing Directories371997
Ref: Zsh/options changing-directories372095
Ref: 9d372095
Node: Completion<2>376235
Ref: Zsh/options completion376364
Ref: 9e376364
Node: Expansion and Globbing382567
Ref: Zsh/options expansion-and-globbing382683
Ref: 9f382683
Node: History394485
Ref: Zsh/options history394602
Ref: a0394602
Node: Initialisation402607
Ref: Zsh/options initialisation402714
Ref: a1402714
Node: Input/Output404598
Ref: Zsh/options input-output404709
Ref: a2404709
Node: Job Control411807
Ref: Zsh/options job-control411913
Ref: a4411913
Node: Prompting415058
Ref: Zsh/options prompting415173
Ref: a6415173
Node: Scripts and Functions417064
Ref: Zsh/options scripts-and-functions417183
Ref: a8417183
Node: Shell Emulation429107
Ref: Zsh/options shell-emulation429231
Ref: ac429231
Node: Shell State<2>442876
Ref: Zsh/options shell-state442982
Ref: af442982
Node: Zle446369
Ref: Zsh/options zle446451
Ref: b0446451
Node: Option Aliases448864
Ref: Zsh/options option-aliases448983
Ref: b1448983
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