Paul Falstad
pf@software.com
Bas de Bakker
bas@phys.uva.nl
zsh is a shell designed for interactive use, although it is also a powerful scripting language. Many of the useful features of bash, ksh, and tcsh were incorporated into zsh; many original features were added. This document details some of the unique features of zsh. It assumes basic knowledge of the standard UNIX shells; the intent is to show a reader already familiar with one of the other major shells what makes zsh more useful or more powerful. This document is not at all comprehensive; read the manual entry for a description of the shell that is complete and concise, although somewhat overwhelming and devoid of examples.
The text will frequently mention options that you can set to change the behaviour of zsh. You can set these options with the command
% setopt optionname
and unset them again with
% unsetopt optionname
Case is ignored in option names, as are embedded underscores.
Otherwise known as globbing, filename generation is quite extensive in zsh. Of course, it has all the basics:
% ls Makefile file.pro foo.o main.o q.c run234 stuff bar.o foo link morestuff run123 run240 sub file.h foo.c main.h pipe run2 run303 % ls *.c foo.c q.c % ls *.[co] bar.o foo.c foo.o main.o q.c % ls foo.? foo.c foo.o % ls *.[^c] bar.o file.h foo.o main.h main.o % ls *.[^oh] foo.c q.c
Also, if the EXTENDEDGLOB option is set, some new features are activated. For example, the ^ character negates the pattern following it:
% setopt extendedglob % ls -d ^*.c Makefile file.pro link morestuff run2 run303 bar.o foo main.h pipe run234 stuff file.h foo.o main.o run123 run240 sub % ls -d ^*.* Makefile link pipe run2 run240 stuff foo morestuff run123 run234 run303 sub % ls -d ^Makefile bar.o foo link morestuff run123 run240 sub file.h foo.c main.h pipe run2 run303 file.pro foo.o main.o q.c run234 stuff % ls -d *.^c .rhosts bar.o file.h file.pro foo.o main.h main.o
An expression of the form <x−y> matches a range of integers:
% ls run<200-300> run234 run240 % ls run<300-400> run303 % ls run<-200> run123 run2 % ls run<300-> run303 % ls run<-> run123 run2 run234 run240 run303
The NUMERICGLOBSORT option will sort files with numbers according to the number. This will not work with ls as it resorts its arguments:
% setopt numericglobsort % echo run<-> run2 run123 run234 run240 run303
Grouping is possible:
% ls (foo|bar).* bar.o foo.c foo.o % ls *.(c|o|pro) bar.o file.pro foo.c foo.o main.o q.c
Also, the string **/ forces a recursive search of subdirectories:
% ls -R Makefile file.pro foo.o main.o q.c run234 stuff bar.o foo link morestuff run123 run240 sub file.h foo.c main.h pipe run2 run303 morestuff: stuff: file xxx yyy stuff/xxx: foobar stuff/yyy: frobar % ls **/*bar stuff/xxx/foobar stuff/yyy/frobar % ls **/f* file.h foo foo.o stuff/xxx/foobar file.pro foo.c stuff/file stuff/yyy/frobar % ls *bar* bar.o % ls **/*bar* bar.o stuff/xxx/foobar stuff/yyy/frobar % ls stuff/**/*bar* stuff/xxx/foobar stuff/yyy/frobar
It is possible to exclude certain files from the patterns using the ~ character. A pattern of the form *.c~bar.c lists all files matching *.c, except for the file bar.c.
% ls *.c foo.c foob.c bar.c % ls *.c~bar.c foo.c foob.c % ls *.c~f* bar.c
One can add a number of qualifiers to the end of any of these patterns, to restrict matches to certain file types. A qualified pattern is of the form
pattern(...)
with single-character qualifiers inside the parentheses.
% alias l='ls -dF' % l * Makefile foo* main.h q.c run240 bar.o foo.c main.o run123 run303 file.h foo.o morestuff/ run2 stuff/ file.pro link@ pipe run234 sub % l *(/) morestuff/ stuff/ % l *(@) link@ % l *(*) foo* link@ morestuff/ stuff/ % l *(x) foo* link@ morestuff/ stuff/ % l *(X) foo* link@ morestuff/ stuff/ % l *(R) bar.o foo* link@ morestuff/ run123 run240 file.h foo.c main.h pipe run2 run303 file.pro foo.o main.o q.c run234 stuff/
Note that *(x) and *(*) both match executables. *(X) matches files executable by others, as opposed to *(x), which matches files executable by the owner. *(R) and *(r) match readable files; *(W) and *(w), which checks for writable files. *(W) is especially important, since it checks for world-writable files:
% l *(w) bar.o foo* link@ morestuff/ run123 run240 file.h foo.c main.h pipe run2 run303 file.pro foo.o main.o q.c run234 stuff/ % l *(W) link@ run240 % l -l link run240 lrwxrwxrwx 1 pfalstad 10 May 23 18:12 link -> /usr/bin/ -rw-rw-rw- 1 pfalstad 0 May 23 18:12 run240
If you want to have all the files of a certain type as well as all symbolic links pointing to files of that type, prefix the qualifier with a -:
% l *(-/) link@ morestuff/ stuff/
You can filter out the symbolic links with the ^ character:
% l *(W^@) run240 % l *(x) foo* link@ morestuff/ stuff/ % l *(x^@/) foo*
To find all plain files, you can use .:
% l *(.) Makefile file.h foo* foo.o main.o run123 run234 run303 bar.o file.pro foo.c main.h q.c run2 run240 sub % l *(^.) link@ morestuff/ pipe stuff/ % l s*(.) stuff/ sub % l *(p) pipe % l -l *(p) prw-r--r-- 1 pfalstad 0 May 23 18:12 pipe
*(U) matches all files owned by you. To search for all files not owned by you, use *(^U):
% l -l *(^U) -rw------- 1 subbarao 29 May 23 18:13 sub
This searches for setuid files:
% l -l *(s) -rwsr-xr-x 1 pfalstad 16 May 23 18:12 foo*
This checks for a certain user's files:
% l -l *(u[subbarao]) -rw------- 1 subbarao 29 May 23 18:13 sub
There are five startup files that zsh will read commands from:
$ZDOTDIR/.zshenv $ZDOTDIR/.zprofile $ZDOTDIR/.zshrc $ZDOTDIR/.zlogin $ZDOTDIR/.zlogout
If ZDOTDIR is not set, then the value of HOME is used; this is the usual case.
.zshenv is sourced on all invocations of the shell, unless the -f option is set. It should contain commands to set the command search path, plus other important environment variables. .zshenv should not contain commands that produce output or assume the shell is attached to a tty.
.zshrc is sourced in interactive shells. It should contain commands to set up aliases, functions, options, key bindings, etc.
.zlogin is sourced in login shells. It should contain commands that should be executed only in login shells. .zlogout is sourced when login shells exit. .zprofile is similar to .zlogin, except that it is sourced before .zshrc. .zprofile is meant as an alternative to .zlogin for ksh fans; the two are not intended to be used together, although this could certainly be done if desired. .zlogin is not the place for alias definitions, options, environment variable settings, etc.; as a general rule, it should not change the shell environment at all. Rather, it should be used to set the terminal type and run a series of external commands (fortune, msgs, etc).
zsh also allows you to create your own commands by defining shell functions. For example:
% yp () {
> ypmatch $1 passwd.byname
> }
% yp pfalstad
pfalstad:*:3564:35:Paul John Falstad:/u/pfalstad:/usr/princeton/bin/zsh
This function looks up a user in the NIS password map. The $1 expands to the first argument to yp. The function could have been equivalently defined in one of the following ways:
% function yp {
> ypmatch $1 passwd.byname
> }
% function yp () {
> ypmatch $1 passwd.byname
> }
% function yp () ypmatch $1 passwd.byname
Note that aliases are expanded when the function definition is parsed, not when the function is executed. For example:
% alias ypmatch=echo % yp pfalstad pfalstad:*:3564:35:Paul John Falstad:/u/pfalstad:/usr/princeton/bin/zsh
Since the alias was defined after the function was parsed, it has no effect on the function's execution. However, if we define the function again with the alias in place:
% function yp () { ypmatch $1 passwd.byname }
% yp pfalstad
pfalstad passwd.byname
it is parsed with the new alias definition in place. Therefore, in general you must define aliases before functions.
We can make the function take multiple arguments:
% unalias ypmatch
% yp () {
> for i
> do ypmatch $i passwd.byname
> done
> }
% yp pfalstad subbarao sukthnkr
pfalstad:*:3564:35:Paul John Falstad:/u/pfalstad:/usr/princeton/bin/zsh
subbarao:*:3338:35:Kartik Subbarao:/u/subbarao:/usr/princeton/bin/zsh
sukthnkr:*:1267:35:Rahul Sukthankar:/u/sukthnkr:/usr/princeton/bin/tcsh
The for i loops through each of the function's arguments, setting i equal to each of them in turn. We can also make the function do something sensible if no arguments are given:
% yp () {
> if (( $# == 0 ))
> then echo usage: yp name ...; fi
> for i; do ypmatch $i passwd.byname; done
> }
% yp
usage: yp name ...
% yp pfalstad sukthnkr
pfalstad:*:3564:35:Paul John Falstad:/u/pfalstad:/usr/princeton/bin/zsh
sukthnkr:*:1267:35:Rahul Sukthankar:/u/sukthnkr:/usr/princeton/bin/tcsh
$# is the number of arguments supplied to the function. If it is equal to zero, we print a usage message; otherwise, we loop through the arguments, and ypmatch all of them.
Here's a function that selects a random line from a file:
% randline () {
> integer z=$(wc -l <$1)
> sed -n $[RANDOM % z + 1]p $1
> }
% randline /etc/motd
PHOENIX WILL BE DOWN briefly Friday morning, 5/24/91 from 8 AM to
% randline /etc/motd
SunOS Release 4.1.1 (PHOENIX) #19: Tue May 14 19:03:15 EDT 1991
% randline /etc/motd
| Please use the "msgs" command to read announcements. Refer to the |
% echo $z
%
randline has a local variable, z, that holds the number of lines in the file. $[RANDOM % z + 1] expands to a random number between 1 and z. An expression of the form $[...] expands to the value of the arithmetic expression within the brackets, and the RANDOM variable returns a random number each time it is referenced. % is the modulus operator, as in C. Therefore, sed -n $[RANDOM%z+1]p picks a random line from its input, from 1 to z.
Function definitions can be viewed with the functions builtin:
% functions randline
randline () {
integer z=$(wc -l <$1)
sed -n $[RANDOM % z + 1]p $1
}
% functions
yp () {
if let $# == 0
then
echo usage: yp name ...
fi
for i
do
ypmatch $i passwd.byname
done
}
randline () {
integer z=$(wc -l <$1)
sed -n $[RANDOM % z + 1]p $1
}
Here's another one:
% cx () { chmod +x $* }
% ls -l foo bar
-rw-r--r-- 1 pfalstad 29 May 24 04:38 bar
-rw-r--r-- 1 pfalstad 29 May 24 04:38 foo
% cx foo bar
% ls -l foo bar
-rwxr-xr-x 1 pfalstad 29 May 24 04:38 bar
-rwxr-xr-x 1 pfalstad 29 May 24 04:38 foo
Note that this could also have been implemented as an alias:
% chmod 644 foo bar % alias cx='chmod +x' % cx foo bar % ls -l foo bar -rwxr-xr-x 1 pfalstad 29 May 24 04:38 bar -rwxr-xr-x 1 pfalstad 29 May 24 04:38 foo
Instead of defining a lot of functions in your .zshrc, all of which you may not use, it is often better to use the autoload builtin. The idea is, you create a directory where function definitions are stored, declare the names in your .zshrc, and tell the shell where to look for them. Whenever you reference a function, the shell will automatically load it into memory.
% mkdir /tmp/funs
% cat >/tmp/funs/yp
ypmatch $1 passwd.byname
^D
% cat >/tmp/funs/cx
chmod +x $*
^D
% FPATH=/tmp/funs
% autoload cx yp
% functions cx yp
undefined cx ()
undefined yp ()
% chmod 755 /tmp/funs/{cx,yp}
% yp egsirer
egsirer:*:3214:35:Emin Gun Sirer:/u/egsirer:/bin/sh
% functions yp
yp () {
ypmatch $1 passwd.byname
}
This idea has other benefits. By adding a #! header to the files, you can make them double as shell scripts. (Although it is faster to use them as functions, since a separate process is not created.)
% ed /tmp/funs/yp 25 i #! /usr/local/bin/zsh w 42 q % </tmp/funs/yp #! /usr/local/bin/zsh ypmatch $1 passwd.byname % /tmp/funs/yp sukthnkr sukthnkr:*:1267:35:Rahul Sukthankar:/u/sukthnkr:/usr/princeton/bin/tcsh
Now other people, who may not use zsh, or who don't want to copy all of your .zshrc, may use these functions as shell scripts.
One nice feature of zsh is the way it prints directories. For example, if we set the prompt like this:
phoenix% PROMPT='%~> ' ~> cd src ~/src>
the shell will print the current directory in the prompt, using the ~ character. However, zsh is smarter than most other shells in this respect:
~/src> cd ~subbarao ~subbarao> cd ~maruchck ~maruchck> cd lib ~maruchck/lib> cd fun ~maruchck/lib/fun> foo=/usr/princeton/common/src ~maruchck/lib/fun> cd ~foo ~foo> cd .. /usr/princeton/common> cd src ~foo> cd news/nntp ~foo/news/nntp> cd inews ~foo/news/nntp/inews>
Note that zsh prints other users' directories in the form ~user. Also note that you can set a parameter and use it as a directory name; zsh will act as if foo is a user with the login directory /usr/princeton/common/src. This is convenient, especially if you're sick of seeing prompts like this:
phoenix:/usr/princeton/common/src/X.V11R4/contrib/clients/xv/docs>
If you get stuck in this position, you can give the current directory a short name, like this:
/usr/princeton/common/src/news/nntp/inews> inews=$PWD /usr/princeton/common/src/news/nntp/inews> echo ~inews /usr/princeton/common/src/news/nntp/inews ~inews>
When you reference a directory in the form ~inews, the shell assumes that you want the directory displayed in this form; thus simply typing echo ~inews or cd ~inews causes the prompt to be shortened. You can define a shell function for this purpose:
~inews> namedir () { $1=$PWD ; : ~$1 }
~inews> cd /usr/princeton/bin
/usr/princeton/bin> namedir pbin
~pbin> cd /var/spool/mail
/var/spool/mail> namedir spool
~spool> cd .msgs
~spool/.msgs>
You may want to add this one-line function to your .zshrc.
zsh can also put the current directory in your title bar, if you are using a windowing system. One way to do this is with the chpwd function, which is automatically executed by the shell whenever you change directory. If you are using xterm, this will work:
chpwd () { print -Pn '^[]2;%~^G' }
The -P option tells print to treat its arguments like a prompt string; otherwise the %~ would not be expanded. The -n option suppresses the terminating newline, as with echo.
If you are using an IRIS wsh, do this:
chpwd () { print -Pn '\2201.y%~\234' }
The print -D command has other uses. For example, to print the current directory to standard output in short form, you can do this:
% print -D $PWD ~subbarao/src
and to print each component of the path in short form:
% print -D $path /bin /usr/bin ~locbin ~locbin/X11 ~/bin
If you use csh, you may know about directory stacks. The pushd command puts the current directory on the stack, and changes to a new directory; the popd command pops a directory off the stack and changes to it.
phoenix% cd phoenix% PROMPT='Z %~> ' Z ~> pushd /tmp /tmp ~ Z /tmp> pushd /usr/etc /usr/etc /tmp ~ Z /usr/etc> pushd /usr/bin /usr/bin /usr/etc /tmp ~ Z /usr/bin> popd /usr/etc /tmp ~ Z /usr/etc> popd /tmp ~ Z /tmp> pushd /etc /etc /tmp ~ Z /etc> popd /tmp ~
zsh's directory stack commands work similarly. One difference is the way pushd is handled if no arguments are given. As in csh, this exchanges the top two elements of the directory stack:
Z /tmp> dirs /tmp ~ Z /tmp> pushd ~ /tmp
unless the stack only has one entry:
Z ~> popd /tmp Z /tmp> dirs /tmp Z /tmp> pushd ~ /tmp Z ~>
or unless the PUSHDTOHOME option is set:
Z ~> setopt pushdtohome Z ~> pushd ~ ~ /tmp
As an alternative to using directory stacks in this manner, we can get something like a directory history by setting a few more options and parameters:
~> DIRSTACKSIZE=8 ~> setopt autopushd pushdminus pushdsilent pushdtohome ~> alias dh='dirs -v' ~> cd /tmp /tmp> cd /usr /usr> cd bin /usr/bin> cd ../pub /usr/pub> dh 0 /usr/pub 1 /usr/bin 2 /usr 3 /tmp 4 ~ /usr/pub> cd -3 /tmp> dh 0 /tmp 1 /usr/pub 2 /usr/bin 3 /usr 4 ~ /tmp> ls ~2/df /usr/bin/df /tmp> cd -4 ~>
Note that ~2 expanded to the second directory in the history list, and that cd -3 recalled the third directory in the list.
You may be wondering what all those options do. AUTOPUSHD made cd act like pushd. (alias cd=pushd is not sufficient, for various reasons.) PUSHDMINUS swapped the meaning of cd +1 and cd -1; we want them to mean the opposite of what they mean in csh, because it makes more sense in this scheme, and it's easier to type:
~> dh 0 ~ 1 /tmp 2 /usr/pub 3 /usr/bin 4 /usr ~> unsetopt pushdminus ~> cd +1 /tmp> dh 0 /tmp 1 ~ 2 /usr/pub 3 /usr/bin 4 /usr /tmp> cd +2 /usr/pub>
PUSHDSILENT keeps the shell from printing the directory stack each time we do a cd, and PUSHDTOHOME we mentioned earlier:
/usr/pub> unsetopt pushdsilent /usr/pub> cd /etc /etc /usr/pub /tmp ~ /usr/bin /usr /etc> cd ~ /etc /usr/pub /tmp ~ /usr/bin /usr ~> unsetopt pushdtohome ~> cd /etc ~ /usr/pub /tmp ~ /usr/bin /usr /etc>
DIRSTACKSIZE keeps the directory stack from getting too large, much like HISTSIZE:
/etc> setopt pushdsilent /etc> cd / /> cd / /> cd / /> cd / /> cd / /> cd / /> cd / /> cd / /> dh 0 / 1 / 2 / 3 / 4 / 5 / 6 / 7 /
Command substitution in zsh can take two forms. In the traditional form, a command enclosed in backquotes (`...`) is replaced on the command line with its output. This is the form used by the older shells. Newer shells (like zsh) also provide another form, $(...). This form is much easier to nest.
% ls -l `echo /vmunix`
-rwxr-xr-x 1 root 1209702 May 14 19:04 /vmunix
% ls -l $(echo /vmunix)
-rwxr-xr-x 1 root 1209702 May 14 19:04 /vmunix
% who | grep mad
subbarao ttyt7 May 23 15:02 (mad55sx15.Prince)
pfalstad ttyu1 May 23 16:25 (mad55sx14.Prince)
subbarao ttyu6 May 23 15:04 (mad55sx15.Prince)
pfalstad ttyv3 May 23 16:25 (mad55sx14.Prince)
% who | grep mad | awk '{print $2}'
ttyt7
ttyu1
ttyu6
ttyv3
% cd /dev; ls -l $(who |
> grep $(echo mad) |
> awk '{ print $2 }')
crwx-w---- 1 subbarao 20, 71 May 23 18:35 ttyt7
crw--w---- 1 pfalstad 20, 81 May 23 18:42 ttyu1
crwx-w---- 1 subbarao 20, 86 May 23 18:38 ttyu6
crw--w---- 1 pfalstad 20, 99 May 23 18:41 ttyv3
Many common uses of command substitution, however, are superseded by other mechanisms of zsh:
% ls -l `tty` crw-rw-rw- 1 root 20, 28 May 23 18:35 /dev/ttyqc % ls -l $TTY crw-rw-rw- 1 root 20, 28 May 23 18:35 /dev/ttyqc % ls -l `which rn` -rwxr-xr-x 1 root 172032 Mar 6 18:40 /usr/princeton/bin/rn % ls -l =rn -rwxr-xr-x 1 root 172032 Mar 6 18:40 /usr/princeton/bin/rn
A command name with a = prepended is replaced with its full pathname. This can be very convenient. If it's not convenient for you, you can turn it off:
% ls =foo =bar % ls =foo =bar zsh: foo not found % setopt noequals % ls =foo =bar =foo =bar
Another nice feature is process substitution:
% who | fgrep -f =(print -l root lemke shgchan subbarao) root console May 19 10:41 lemke ttyq0 May 22 10:05 (narnia:0.0) lemke ttyr7 May 22 10:05 (narnia:0.0) lemke ttyrd May 22 10:05 (narnia:0.0) shgchan ttys1 May 23 16:52 (gaudi.Princeton.) subbarao ttyt7 May 23 15:02 (mad55sx15.Prince) subbarao ttyu6 May 23 15:04 (mad55sx15.Prince) shgchan ttyvb May 23 16:51 (gaudi.Princeton.)
A command of the form =(...) is replaced with the name of a file containing its output. (A command substitution, on the other hand, is replaced with the output itself.) print -l is like echo, excepts that it prints its arguments one per line, the way fgrep expects them:
% print -l foo bar foo bar
We could also have written:
% who | fgrep -f =(echo 'root > lemke > shgchan > subbarao')
Using process substitution, you can edit the output of a command:
% ed =(who | fgrep -f ~/.friends) 355 g/lemke/d w /tmp/filbar 226 q % cat /tmp/filbar root console May 19 10:41 shgchan ttys1 May 23 16:52 (gaudi.Princeton.) subbarao ttyt7 May 23 15:02 (mad55sx15.Prince) subbarao ttyu6 May 23 15:04 (mad55sx15.Prince) shgchan ttyvb May 23 16:51 (gaudi.Princeton.)
or easily read archived mail:
% mail -f =(zcat ~/mail/oldzshmail.Z) "/tmp/zsha06024": 84 messages, 0 new, 43 unread > 1 U TO: pfalstad, zsh (10) 2 U nytim!tim@uunet.uu.net, Re: Zsh on Sparc1 /SunOS 4.0.3 3 U JAM%TPN@utrcgw.utc.com, zsh fix (15) 4 U djm@eng.umd.edu, way to find out if running zsh? (25) 5 U djm@eng.umd.edu, Re: way to find out if running zsh? (17) 6 r djm@eng.umd.edu, Meta . (18) 7 U jack@cs.glasgow.ac.uk, Re: problem building zsh (147) 8 U nytim!tim@uunet.uu.net, Re: Zsh on Sparc1 /SunOS 4.0.3 9 ursa!jmd, Another fix... (61) 10 U pplacewa@bbn.com, Re: v18i084: Zsh 2.00 - A small complaint (36) 11 U lubkin@cs.rochester.edu, POSIX job control (34) 12 U yale!bronson!tan@uunet.UU.NET 13 U brett@rpi.edu, zsh (36) 14 S subbarao, zsh sucks!!!! (286) 15 U snibru!d241s008!d241s013!ala@relay.EU.net, zsh (165) 16 U nytim!tim@uunet.UU.NET, Re: Zsh on Sparc1 /SunOS 4.0.3 17 U subbarao, zsh is a junk shell (43) 18 U amaranth@vela.acs.oakland.edu, zsh (33) 43u/84 1: x % ls -l /tmp/zsha06024 /tmp/zsha06024 not found
Note that the shell creates a temporary file, and deletes it when the command is finished.
% diff =(ls) =(ls -F) 3c3 < fortune --- > fortune* 10c10 < strfile --- > strfile*
If you read zsh's man page, you may notice that <(...) is another form of process substitution which is similar to =(...). There is an important difference between the two. In the <(...) case, the shell creates a named pipe (FIFO) instead of a file. This is better, since it does not fill up the file system; but it does not work in all cases. In fact, if we had replaced =(...) with <(...) in the examples above, all of them would have stopped working except for fgrep -f <(...). You can not edit a pipe, or open it as a mail folder; fgrep, however, has no problem with reading a list of words from a pipe. You may wonder why diff <(foo) bar doesn't work, since foo | diff - bar works; this is because diff creates a temporary file if it notices that one of its arguments is -, and then copies its standard input to the temporary file.
>(...) is just like <(...) except that the command between the parentheses will get its input from the named pipe.
% dvips -o >(lpr) zsh.dvi
Apart from all the regular redirections like the Bourne shell has, zsh can do more. You can send the output of a command to more than one file, by specifying more redirections like
% echo Hello World >file1 >file2
and the text will end up in both files. Similarly, you can send the output to a file and into a pipe:
% make > make.log | grep Error
The same goes for input. You can make the input of a command come from more than one file.
% sort <file1 <file2 <file3
The command will first get the contents of file1 as its standard input, then those of file2 and finally the contents of file3. This, too, works with pipes.
% cut -d: -f1 /etc/passwd | sort <newnames
The sort will get as its standard input first the output of cut and then the contents of newnames.
Suppose you would like to watch the standard output of a command on your terminal, but want to pipe the standard error to another command. An easy way to do this in zsh is by redirecting the standard error using 2> >(...).
% find / -name games 2> >(grep -v 'Permission' > realerrors)
The above redirection will actually be implemented with a regular pipe, not a temporary named pipe.
Often-used commands can be abbreviated with an alias:
% alias uc=uncompress % ls hanoi.Z % uc hanoi % ls hanoi
or commands with certain desired options:
% alias fm='finger -m' % fm root Login name: root In real life: Operator Directory: / Shell: /bin/csh On since May 19 10:41:15 on console 3 days 5 hours Idle Time No unread mail No Plan. % alias lock='lock -p -60000' % lock lock: /dev/ttyr4 on phoenix. timeout in 60000 minutes time now is Fri May 24 04:23:18 EDT 1991 Key: % alias l='ls -AF' % l / .bash_history kadb* .bashrc lib@ .cshrc licensed/ .exrc lost+found/ .login macsyma ...
Aliases can also be used to replace old commands:
% alias grep=egrep ps=sps make=gmake % alias whoami='echo root' % whoami root
or to define new ones:
% cd / % alias sz='ls -l | sort -n +3 | tail -10' % sz drwxr-sr-x 7 bin 3072 May 23 11:59 etc drwxrwxrwx 26 root 5120 May 24 04:20 tmp drwxr-xr-x 2 root 8192 Dec 26 19:34 lost+found drwxr-sr-x 2 bin 14848 May 23 18:48 dev -r--r--r-- 1 root 140520 Dec 26 20:08 boot -rwxr-xr-x 1 root 311172 Dec 26 20:08 kadb -rwxr-xr-x 1 root 1209695 Apr 16 15:33 vmunix.old -rwxr-xr-x 1 root 1209702 May 14 19:04 vmunix -rwxr-xr-x 1 root 1209758 May 21 12:23 vmunix.new.kernelmap.old -rwxr-xr-x 1 root 1711848 Dec 26 20:08 vmunix.org % cd % alias rable='ls -AFtrd *(R)' nrable='ls -AFtrd *(^R)' % rable README func/ bin/ pub/ News/ src/ nicecolors etc/ scr/ tmp/ iris/ zsh* % nrable Mailboxes/ mail/ notes
(The pattern *(R) matches all readable files in the current directory, and *(^R) matches all unreadable files.)
Most other shells have aliases of this kind (command aliases). However, zsh also has global aliases, which are substituted anywhere on a line. Global aliases can be used to abbreviate frequently-typed usernames, hostnames, etc.
% alias -g me=pfalstad gun=egsirer mjm=maruchck % who | grep me pfalstad ttyp0 May 24 03:39 (mickey.Princeton) pfalstad ttyp5 May 24 03:42 (mickey.Princeton) % fm gun Login name: egsirer In real life: Emin Gun Sirer Directory: /u/egsirer Shell: /bin/sh Last login Thu May 23 19:05 on ttyq3 from bow.Princeton.ED New mail received Fri May 24 02:30:28 1991; unread since Fri May 24 02:30:27 1991 % alias -g phx=phoenix.princeton.edu warc=wuarchive.wustl.edu % ftp warc Connected to wuarchive.wustl.edu.
Here are some more interesting uses.
% alias -g M='| more' GF='| fgrep -f ~/.friends' % who M # pipes the output of who through more % who GF # see if your friends are on % w GF # see what your friends are doing
Another example makes use of zsh's process substitution. If you run NIS, and you miss being able to do this:
% grep pfalstad /etc/passwd
you can define an alias that will seem more natural than ypmatch pfalstad passwd:
% alias -g PASS='<(ypcat passwd)' % grep pfalstad PASS pfalstad:*:3564:35:Paul John Falstad:/u/pfalstad:/usr/princeton/bin/zsh
If you're really crazy, you can even call it /etc/passwd:
% alias -g /etc/passwd='<(ypcat passwd)' % grep pfalstad /etc/passwd pfalstad:*:3564:35:Paul John Falstad:/u/pfalstad:/usr/princeton/bin/zsh
The last example shows one of the perils of global aliases; they have a lot of potential to cause confusion. For example, if you defined a global alias called | (which is possible), zsh would begin to act very strangely; every pipe symbol would be replaced with the text of your alias. To some extent, global aliases are like macros in C; discretion is advised in using them and in choosing names for them. Using names in all caps is not a bad idea, especially for aliases which introduce shell metasyntax (like M and GF above).
Note that zsh aliases are not like csh aliases. The syntax for defining them is different, and they do not have arguments. All your favorite csh aliases will probably not work under zsh. For example, if you try:
alias rm mv '\!* /tmp/wastebasket'
no aliases will be defined, but zsh will not report an error. In csh, this line defines an alias that makes rm safe---files that are rm'd will be moved to a temporary directory instead of instantly destroyed. In zsh's syntax, however, this line asks the shell to print any existing alias definitions for rm, mv, or !* /tmp/wastebasket. Since there are none, most likely, the shell will not print anything, although alias will return a nonzero exit code. The proper syntax is this:
alias rm='mv \!* /tmp/wastebasket'
However, this won't work either:
% rm foo.dvi zsh: no matches found: !*
While this makes rm safe, it is certainly not what the user intended. In zsh, you must use a shell function for this:
% unalias rm
% rm () { mv $* /tmp/wastebasket }
% rm foo.dvi
% ls /tmp/wastebasket
foo.dvi
While this is much cleaner and easier to read (I hope you will agree), it is not csh-compatible. Therefore, a script to convert csh aliases and variables has been provided. You should only need to use it once, to convert all your csh aliases and parameters to zsh format:
% csh
csh> alias
l ls -AF
more less
on last -2 !:1 ; who | grep !:1
csh> exit
% c2z >neat_zsh_aliases
% cat neat_zsh_aliases
alias l='ls -AF'
alias more='less'
on () { last -2 $1 ; who | grep $1 }
...
The first two aliases were converted to regular zsh aliases, while the third, since it needed to handle arguments, was converted to a function. c2z can convert most aliases to zsh format without any problems. However, if you're using some really arcane csh tricks, or if you have an alias with a name like do (which is reserved in zsh), you may have to fix some of the aliases by hand.
The c2z script checks your csh setup, and produces a list of zsh commands which replicate your aliases and parameter settings as closely as possible. You could include its output in your startup file, .zshrc.
There are several ways to manipulate history in zsh. One way is to use csh-style ! history:
% /usr/local/bin/!:0 !-2*:s/foo/bar/ >>!$
If you don't want to use this, you can turn it off by typing setopt nobanghist. If you are afraid of accidentally executing the wrong command you can set the HISTVERIFY option. If this option is set, commands that result from history expansion will not be executed immediately, but will be put back into the editor buffer for further consideration.
If you're not familiar with ! history, here follows some explanation. History substitutions always start with a !, commonly called “bang”. After the ! comes an (optional) designation of which “event” (command) to use, then a colon, and then a designation of what word of that command to use. For example, !-n refers to the command n commands ago.
% ls foo bar % cd foo % !-2 ls baz bam
No word designator was used, which means that the whole command referred to was repeated. Note that the shell will echo the result of the history substitution. The word designator can, among other things, be a number indicating the argument to use, where 0 is the command.
% /usr/bin/ls foo foo % !:0 bar /usr/bin/ls bar bar
In this example, no event designator was used, which tells zsh to use the previous command. A $ specifies the last argument
% mkdir /usr/local/lib/emacs/site-lisp/calc % cd !:$ cd /usr/local/lib/emacs/site-lisp/calc
If you use more words of the same command, only the first ! needs an event designator.
% make prig >> make.log make: *** No rule to make target `prig'. Stop. % cd src % !-2:0 prog >> !:$ make prog >> make.log
This is different from csh, where a bang with no event designator always refers to the previous command. If you actually like this behaviour, set the CSHJUNKIEHISTORY option.
% setopt cshjunkiehistory % !-2:0 prog2 >> !:$ make prog2 >> cshjunkiehistory
Another way to use history is to use the fc command. For example, if you type an erroneous command:
% for i in `cat /etc/clients` do rpu $i done zsh: command not found: rpu zsh: command not found: rpu zsh: command not found: rpu ...
typing fc will execute an editor on this command, allowing you to fix it. (The default editor is vi, by the way, not ed).
% fc
49
/rpu/s//rup/p
rup $i
w
49
q
for i in `cat /etc/clients`
do
rup $i
done
beam up 2 days, 10:17, load average: 0.86, 0.80, 0.50
bow up 4 days, 8:41, load average: 0.91, 0.80, 0.50
burn up 17:18, load average: 0.91, 0.80, 0.50
burst up 9 days, 1:49, load average: 0.95, 0.80, 0.50
tan up 11:14, load average: 0.91, 0.80, 0.50
bathe up 3 days, 17:49, load average: 1.84, 1.79, 1.50
bird up 1 day, 9:13, load average: 1.95, 1.82, 1.51
bonnet up 2 days, 21:18, load average: 0.93, 0.80, 0.50
...
A variant of the fc command is r, which redoes the last command, with optional changes:
% echo foo foo % r echo foo foo % echo foo foo % r foo=bar echo bar bar
zsh's command line editor, ZLE, is quite powerful. It is designed to emulate either emacs or vi; the default is emacs. To set the bindings for vi mode, type bindkey -v. If your EDITOR or VISUAL environment variable is vi, zsh will use vi emulation by default. You can then switch to emacs mode with bindkey -e.
In addition to basic editing, the shell allows you to recall previous lines in the history. In emacs mode, this is done with ^P (control-P) or (on many terminals) with the cursor-up key:
% ls ~ - README file mail pub tmp Mailboxes bin func nicecolors scr zsh News etc iris notes src % echo foobar foobar % ^P % echo foobar^P % ls ~_
Pressing ^P once brings up the previous line (echo foobar); pressing it again brings up the line before that (ls ~). The cursor is left at the end of the line, allowing you to edit the line if desired before executing it. In many cases, ZLE eliminates the need for the fc command, since it is powerful enough to handle even multiline commands:
% for i in a b c d e > do > echo $i > done a b c d e % ^P % for i in a b c d e do echo $i done_
Now you can just move up to the part you want to change...
% for i in _ b c d e do echo $i done
change it, and execute the new command.
% for i in f g h i j do echo $i done f g h i j
Also, you can search the history for a certain command using ESC-P, this will look for the last command that started with the (part of the) word at the beginning of the current line. Hitting ESC-P another time gets you the command before that, etc.
% set ESC-P % setopt autolist ESC-P % setopt nocorrect_
Another way is to do an incremental search, emacs-style:
% ^R % _ i-search: % l_ /usr/bin i-search: l % date > foofile_c i-search: le
Suppose you have retrieved an old history event in one of these ways and would like to execute several consecutive old commands starting with this one. ^O will execute the current command and then put the next command from the history into the editor buffer. Typing ^O several times will therefore reexecute several consecutive commands from the history. Of course, you can edit some of those commands in between.
In addition to completion (see below), TAB performs expansion if possible.
% ls *.cTAB % ls foofile.c fortune.c rnd.c strfile.c unstr.c_
For example, suppose you have a bunch of weird files in an important directory:
% ls * * * ; & % $??foo dspfok foo.c !"foo"! ` \ ` foo rrr
You want to remove them, but you don't want to damage foo.c. Here is one way to do this:
% rm *TAB % rm \ \ \*\ \*\ \*\ \ \ \!\"foo\"\! \;\ \&\ %\ \$'´ 'foo \`\ \\\ \` dspfok foo foo.c rrr_
When you expand *, zsh inserts the names of all the files into the editing buffer, with proper shell quoting. Now, just move back and remove foo.c from the buffer:
% rm \ \ \*\ \*\ \*\ \ \ \!\"foo\"\! \;\ \&\ %\ \$'´ 'foo \`\ \\\ \` dspfok foo _rr
and press return. Everything except foo.c will be deleted from the directory. If you do not want to actually expand the current word, but would like to see what the matches are, type ^Xg.
% rm f*^Xg foo foo.c % rm f*_
Here's another trick; let's say you have typed this command in:
% gcc -o x.out foob.c -g -Wpointer-arith -Wtrigraphs_
and you forget which library you want. You need to escape out for a minute and check by typing ls /usr/lib, or some other such command; but you don't want to retype the whole command again, and you can't press return now because the current command is incomplete. In zsh, you can put the line on the buffer stack, using ESC-Q, and type some other commands. The next time a prompt is printed, the gcc line will be popped off the stack and put in the editing buffer automatically; you can then enter the proper library name and press return (or, ESC-Q again and look for some other libraries whose names you forgot).
A similar situation: what if you forget the option to gcc that finds bugs using AI techniques? You could either use ESC-Q again, and type man gcc, or you could press ESC-H, which essentially does the same thing; it puts the current line on the buffer stack, and executes the command run-help gcc, where run-help is an alias for man.
Another interesting command is ESC-A. This executes the current line, but retains it in the buffer, so that it appears again when the next prompt is printed. Also, the cursor stays in the same place. This is useful for executing a series of similar commands:
% cc grok.c -g -lc -lgl -lsun -lmalloc -Bstatic -o b.out % cc fubar.c -g -lc -lgl -lsun -lmalloc -Bstatic -o b.out % cc fooble.c -g -lc -lgl -lsun -lmalloc -Bstatic -o b.out
The ESC-' command is useful for managing the shell's quoting conventions. Let's say you want to print this string:
don't do that; type 'rm -rf \*', with a \ before the *.
All that is necessary is to type it into the editing buffer:
% don't do that; type 'rm -rf \*', with a \ before the *.
press ESC-' (escape-quote):
% 'don'\''t do that; type '\''rm -rf \*'\'', with a \ before the *.'
then move to the beginning and add the echo command.
% echo 'don'\''t do that; type '\''rm -rf \*'\'', with a \ before the *.' don't do that; type 'rm -rf \*', with a \ before the *.
Let's say you want to create an alias to do this echo command. This can be done by recalling the line with ^P and pressing ESC-' again:
% 'echo '\''don'\''\'\'''\''t do that; type '\''\'\'''\''rm -rf \*'\''\'\'''\'', with a \ before the *.'\'''
and then move to the beginning and add the command to create an alias.
% alias zoof='echo '\''don'\''\'\'''\''t do that; type '\''\'\'''\''rm -rf \*'\''\'\'''\'', with a \ before the *.'\''' % zoof don't do that; type 'rm -rf \*', with a \ before the *.
If one of these fancy editor commands changes your command line in a way you did not intend, you can undo changes with ^_, if you can get it out of your keyboard, or ^X^U, otherwise.
Another use of the editor is to edit the value of variables. For example, an easy way to change your path is to use the vared command:
% vared PATH > /u/pfalstad/scr:/u/pfalstad/bin/sun4:/u/maruchck/scr:/u/subbarao/bin:/u/maruc hck/bin:/u/subbarao/scripts:/usr/princeton/bin:/usr/ucb:/usr/bin:/bin:/usr/host s:/usr/princeton/bin/X11:/./usr/lang:/./usr/etc:/./etc
You can now edit the path. When you press return, the contents of the edit buffer will be assigned to PATH.
Another great zsh feature is completion. If you hit TAB, zsh will complete all kinds of stuff. Like commands or filenames:
% compTAB % compress _ % ls nicTAB % ls nicecolors _ % ls /usr/prTAB % ls /usr/princeton/_ % ls -l =comTAB % ls -l =compress _
If the completion is ambiguous, the editor will beep. If you find this annoying, you can set the NOLISTBEEP option. Completion can even be done in the middle of words. To use this, you will have to set the COMPLETEINWORD option:
% setopt completeinword % ls /usr/p_onTAB % ls /usr/prince_on/ % setopt alwaystoend % ls /usr/p_onTAB % ls /usr/princeton/_
You can list possible completions by pressing ^D:
% ls /vmuTAB —beep— % ls /vmunix_ % ls /vmunix^D vmunix vmunix.old vmunix.new.kernelmap.old vmunix.org
Or, you could just set the AUTOLIST option:
% setopt autolist % ls /vmuTAB —beep— vmunix vmunix.old vmunix.new.kernelmap.old vmunix.org % ls /vmunix_
If you like to see the types of the files in these lists, like in ls -F, you can set the LISTTYPES option. Together with AUTOLIST you can use LISTAMBIGUOUS. This will only list the possibilities if there is no unambiguous part to add:
% setopt listambiguous % ls /vmuTAB —beep— % ls /vmunix_TAB —beep— vmunix vmunix.old vmunix.new.kernelmap.old vmunix.org
If you don't want several of these listings to scroll the screen so much, the ALWAYSLASTPROMPT option is useful. If set, you can continue to edit the line you were editing, with the completion listing appearing beneath it.
Another interesting option is MENUCOMPLETE. This affects the way TAB works. Let's look at the /vmunix example again:
% setopt menucomplete % ls /vmuTAB % ls /vmunixTAB % ls /vmunix.new.kernelmap.oldTAB % ls /vmunix.old_
Each time you press TAB, it displays the next possible completion. In this way, you can cycle through the possible completions until you find the one you want.
The AUTOMENU option makes a nice compromise between this method of completion and the regular method. If you set this option, pressing TAB once completes the unambiguous part normally, pressing the TAB key repeatedly after an ambiguous completion will cycle through the possible completions.
Another option you could set is RECEXACT, which causes exact matches to be accepted, even if there are other possible completions:
% setopt recexact % ls /vmuTAB —beep— vmunix vmunix.old vmunix.new.kernelmap.old vmunix.org % ls /vmunix_TAB % ls /vmunix _
To facilitate the typing of pathnames, a slash will be added whenever a directory is completed. Some computers don't like the spurious slashes at the end of directory names. In that case, the AUTOREMOVESLASH option comes to rescue. It will remove these slashes when you type a space or return after them.
The fignore variable lists suffixes of files to ignore during completion.
% ls fooTAB —beep— foofile.c foofile.o % fignore=( .o \~ .bak .junk ) % ls fooTAB % ls foofile.c _
Since foofile.o has a suffix that is in the fignore list, it was not considered a possible completion of foo.
Username completion is also supported:
% ls ~pfalTAB % ls ~pfalstad/_
and parameter name completion:
% echo $ORGTAB
% echo $ORGANIZATION _
% echo ${ORGTAB
% echo ${ORGANIZATION _
Note that in the last example a space is added after the completion as usual. But if you want to add a colon or closing brace, you probably don't want this extra space. Setting the AUTOPARAMKEYS option will automatically remove this space if you type a colon or closing brace after such a completion.
There is also option completion:
% setopt noclTAB % setopt noclobber _
and binding completion:
% bindkey '^X^X' puTAB % bindkey '^X^X' push-line _
The compctl command is used to control completion of the arguments of specific commands. For example, to specify that certain commands take other commands as arguments, you use compctl -c:
% compctl -c man nohup % man uptTAB % man uptime _
To specify that a command should complete filenames, you should use compctl -f. This is the default. It can be combined with -c, as well.
% compctl -cf echo % echo uptTAB % echo uptime _ % echo foTAB % echo foo.c
Similarly, use -o to specify options, -v to specify variables, and -b to specify bindings.
% compctl -o setopt unsetopt % compctl -v typeset vared unset export % compctl -b bindkey
You can also use -k to specify a custom list of keywords to use in completion. After the -k comes either the name of an array or a literal array to take completions from.
% ftphosts=(ftp.uu.net wuarchive.wustl.edu) % compctl -k ftphosts ftp % ftp wuTAB % ftp wuarchive.wustl.edu _ % compctl -k '(cpirazzi subbarao sukthnkr)' mail finger % finger cpTAB % finger cpirazzi _
To better specify the files to complete for a command, use the -g option which takes any glob pattern as an argument. Be sure to quote the glob patterns as otherwise they will be expanded when the compctl command is run.
% ls letter.tex letter.dvi letter.aux letter.log letter.toc % compctl -g '*.tex' latex % compctl -g '*.dvi' xdvi dvips % latex lTAB % latex letter.tex _ % xdvi lTAB % xdvi letter.dvi _
Glob patterns can include qualifiers within parentheses. To rmdir only directories and cd to directories and symbolic links pointing to them:
% compctl -g '*(-/)' cd % compctl -g '*(/)' rmdir
RCS users like to run commands on files which are not in the current directory, but in the RCS subdirectory where they all get ,v suffixes. They might like to use
% compctl -g 'RCS/*(:t:s/\,v//)' co rlog rcs % ls RCS builtin.c,v lex.c,v zle_main.c,v % rlog buTAB % rlog builtin.c _
The :t modifier keeps only the last part of the pathname and the :s/\,v// will replace any ,v by nothing.
The -s flag is similar to -g, but it uses all expansions, instead of just globbing, like brace expansion, parameter substitution and command substitution.
% compctl -s '$(setopt)' unsetopt
will only complete options which are actually set to be arguments to unsetopt.
Sometimes a command takes another command as its argument. You can tell zsh to complete commands as the first argument to such a command and then use the completion method of the second command. The -l flag with a null-string argument is used for this.
% compctl -l '' nohup exec % nohup compTAB % nohup compress _ % nohup compress filTAB % nohup compress filename _
Sometimes you would like to run really complicated commands to find out what the possible completions are. To do this, you can specify a shell function to be called that will assign the possible completions to a variable called reply. Note that this variable must be an array. Here's another (much slower) way to get the completions for co and friends:
% function getrcs {
> reply=()
> for i in RCS/*
> do
> reply=($reply[*] $(basename $i ,v))
> done
> }
% compctl -K getrcs co rlog rcs
Some command arguments use a prefix that is not a part of the things to complete. The kill builtin command takes a signal name after a -. To make such a prefix be ignored in the completion process, you can use the -P flag.
% compctl -P - -k signals kill % kill -HTAB % kill -HUP _
TeX is usually run on files ending in .tex, but also sometimes on other files. It is somewhat annoying to specify that the arguments of TeX should end in .tex and then not be able to complete these other files. Therefore you can specify things like “Complete to files ending in .tex if available, otherwise complete to any filename.”. This is done with xored completion:
% compctl -g '*.tex' + -f tex
The + tells the editor to only take the next thing into account if the current one doesn't generate any matches. If you have not changed the default completion, the above example is in fact equivalent to
% compctl -g '*.tex' + tex
as a lone + at the end is equivalent to specifying the default completion after the +. This form of completion is also frequently used if you want to run some command only on a certain type of files, but not necessarily in the current directory. In this case you will want to complete both files of this type and directories. Depending on your preferences you can use either of
% compctl -g '*.ps' + -g '*(-/)' ghostview % compctl -g '*.ps *(-/)' ghostview
where the first one will only complete directories (and symbolic links pointing to directories) if no postscript file matches the already typed part of the argument.
If you play with completion, you will soon notice that you would like to specify what to complete, depending on what flags you give to the command and where you are on the command line. For example, a command could take any filename argument after a -f flag, a username after a -u flag and an executable after a -x flag. This section will introduce you to the ways to specify these things. To many people it seems rather difficult at first, but taking the trouble to understand it can save you lots of typing in the end. Even I keep being surprised when zsh manages to complete a small or even empty prefix to the right file in a large directory.
To tell zsh about these kinds of completion, you use “extended completion” by specifying the -x flag to compctl. The -x flag takes a list of patterns/flags pairs. The patterns specify when to complete and the flags specify what. The flags are simply those mentioned above, like -f or -g glob pattern.
As an example, the r[string1,string2] pattern matches if the cursor is after something that starts with string1 and before something that starts with string2. The string2 is often something that you do not want to match anything at all.
% ls foo1 bar1 foo.Z bar.Z % compctl -g '^*.Z' -x 'r[-d,---]' -g '*.Z' -- compress % compress fTAB % compress foo1 _ % compress -d fTAB % compress -d foo.Z _
In the above example, if the cursor is after the -d the pattern will match and therefore zsh uses the -g *.Z flag that will only complete files ending in .Z. Otherwise, if no pattern matches, it will use the flags before the -x and in this case complete every file that does not end in .Z.
The s[string] pattern matches if the current word starts with string. The string itself is not considered to be part of the completion.
% compctl -x 's[-]' -k signals -- kill % kill -HTAB % kill -HUP _
The tar command takes a tar file as an argument after the -f option. The c[offset,string] pattern matches if the word in position offset relative to the current word is string. More in particular, if offset is -1, it matches if the previous word is string. This suggests
% compctl -f -x 'c[-1,-f]' -g '*.tar' -- tar
But this is not enough. The -f option could be the last of a longer string of options. C[...,...] is just like c[...,...], except that it uses glob-like pattern matching for string. So
% compctl -f -x 'C[-1,-*f]' -g '*.tar' -- tar
will complete tar files after any option string ending in an f. But we'd like even more. Old versions of tar used all options as the first argument, but without the minus sign. This might be inconsistent with option usage in all other commands, but it is still supported by newer versions of tar. So we would also like to complete tar files if the first argument ends in an f and we're right behind it.
We can `and' patterns by putting them next to each other with a space between them. We can `or' these sets by putting comma's between them. We will also need some new patterns. p[num] will match if the current argument (the one to be completed) is the numth argument. W[index,pattern] will match if the argument in place index matches the pattern. This gives us
% compctl -f -x 'C[-1,-*f] , W[1,*f] p[2]' -g '*.tar' -- tar
In words: If the previous argument is an option string that ends in an f, or the first argument ended in an f and it is now the second argument, then complete only filenames ending in .tar.
All the above examples used only one set of patterns with one completion flag. You can use several of these pattern/flag pairs separated by a -. The first matching pattern will be used. Suppose you have a version of tar that supports compressed files by using a -Z option. Leaving the old tar syntax aside for a moment, we would like to complete files ending in .tar.Z if a -Z option has been used and files ending in .tar otherwise, all this only after a -f flag. Again, the -Z can be alone or it can be part of a longer option string, perhaps the same as that of the -f flag. Here's how to do it; note the backslash and the secondary prompt which are not part of the compctl command.
% compctl -f -x 'C[-1,-*Z*f] , R[-*Z*,---] C[-1,-*f]' -g '*.tar.Z' - \ > 'C[-1,-*f]' -g '*.tar' -- tar
The first pattern set tells us to match if either the previous argument was an option string including a Z and ending in an f or there was an option string with a Z somewhere and the previous word was any option string ending in an f. If this is the case, we need a compressed tar file. Only if this is not the case the second pattern set will be considered. By the way, R[pattern1,pattern2] is just like r[...,...] except that it uses pattern matching with shell metacharacters instead of just strings.
You will have noticed the -- before the command name. This ends the list of pattern/flag pairs of -x. It is usually used just before the command name, but you can also use an extended completion as one part of a list of xored completions, in which case the -- appears just before one of the + signs.
Note the difference between using extended completion as part of a list of xored completions as in
% ls foo bar % compctl -x 'r[-d,---]' -g '*.Z' -- + -g '^*.Z' compress % compress -d fTAB % compress -d foo _
and specifying something before the -x as in
% compctl -g '^*.Z' -x 'r[-d,---]' -g '*.Z' -- compress % compress -d fTAB % compress -d f_
In the first case, the alternative glob pattern (^*.Z) will be used if the first part does not generate any possible completions, while in the second case the alternative glob pattern will only be used if the r[...] pattern doesn't match.
Each of the editor commands we have seen was actually a function bound by default to a certain key. The real names of the commands are:
expand-or-complete TAB push-line ESC-Q run-help ESC-H accept-and-hold ESC-A quote-line ESC-'
These bindings are arbitrary; you could change them if you want. For example, to bind accept-line to ^Z:
% bindkey '^Z' accept-line
Another idea would be to bind the delete key to delete-char; this might be convenient if you use ^H for backspace.
% bindkey '^?' delete-char
Or, you could bind ^X^H to run-help:
% bindkey '^X^H' run-help
Other examples:
% bindkey '^X^Z' universal-argument % bindkey ' ' magic-space % bindkey -s '^T' 'uptime > ' % bindkey '^Q' push-line-or-edit
universal-argument multiplies the next command by 4. Thus ^X^Z^W might delete the last four words on the line. If you bind space to magic-space, then csh-style history expansion is done on the line whenever you press the space bar.
Something that often happens is that I am typing a multiline command and discover an error in one of the previous lines. In this case, push-line-or-edit will put the entire multiline construct into the editor buffer. If there is only a single line, it is equivalent to push-line.
The -s flag to bindkey specifies that you are binding the key to a string, not a command. Thus bindkey -s '^T' 'uptime\n' lets you VMS lovers get the load average whenever you press ^T.
If you have a NeXT keyboard, the one with the | and \ keys very inconveniently placed, the following bindings may come in handy:
% bindkey -s '\e/' '\\' % bindkey -s '\e=' '|'
Now you can type ALT-/ to get a backslash, and ALT-= to get a vertical bar. This only works inside zsh, of course; bindkey has no effect on the key mappings inside talk or mail, etc.
Some people like to bind ^S and ^Q to editor commands. Just binding these has no effect, as the terminal will catch them and use them for flow control. You could unset them as stop and start characters, but most people like to use these for external commands. The solution is to set the NOFLOWCONTROL option. This will allow you to bind the start and stop characters to editor commands, while retaining their normal use for external commands.
In zsh, parameters are set like this:
% foo=bar % echo $foo bar
Spaces before or after the = are frowned upon:
% foo = bar zsh: command not found: foo
Also, set doesn't work for setting parameters:
% set foo=bar % set foo = bar % echo $foo %
Note that no error message was printed. This is because both of these commands were perfectly valid; the set builtin assigns its arguments to the positional parameters ($1, $2, etc.).
% set foo=bar % echo $1 foo=bar % set foo = bar % echo $3 $2 bar =
If you're really intent on using the csh syntax, define a function like this:
% set () {
> eval "$1$2$3"
> }
% set foo = bar
% set fuu=brrr
% echo $foo $fuu
bar brrr
But then, of course you can't use the form of set with options, like set -F (which turns off filename generation). Also, the set command by itself won't list all the parameters like it should. To get around that you need a case statement:
% set () {
> case $1 in
> -*|+*|'') builtin set $* ;;
> *) eval "$1$2$3" ;;
> esac
> }
For the most part, this should make csh users happy.
The following sh-style operators are supported in zsh:
% unset null
% echo ${foo-xxx}
bar
% echo ${null-xxx}
xxx
% unset null
% echo ${null=xxx}
xxx
% echo $null
xxx
% echo ${foo=xxx}
bar
% echo $foo
bar
% unset null
% echo ${null+set}
% echo ${foo+set}
set
Also, csh-style : modifiers may be appended to a parameter substitution.
% echo $PWD /home/learning/pf/zsh/zsh2.00/src % echo $PWD:h /home/learning/pf/zsh/zsh2.00 % echo $PWD:h:h /home/learning/pf/zsh % echo $PWD:t src % name=foo.c % echo $name foo.c % echo $name:r foo % echo $name:e c
The equivalent constructs in ksh (which are also supported in zsh) are a bit more general and easier to remember. When the shell expands ${foo#pat}, it checks to see if pat matches a substring at the beginning of the value of foo. If so, it removes that portion of foo, using the shortest possible match. With ${foo##pat}, the longest possible match is removed. ${foo%pat} and ${foo%%pat} remove the match from the end. Here are the ksh equivalents of the : modifiers:
% echo ${PWD%/*}
/home/learning/pf/zsh/zsh2.00
% echo ${PWD%/*/*}
/home/learning/pf/zsh
% echo ${PWD##*/}
src
% echo ${name%.*}
foo
% echo ${name#*.}
c
zsh also has upper/lowercase modifiers:
% xx=Test % echo $xx:u TEST % echo $xx:l test
and a substitution modifier:
% echo $name:s/foo/bar/ bar.c % ls foo.c foo.h foo.o foo.pro % for i in foo.*; mv $i $i:s/foo/bar/ % ls bar.c bar.h bar.o bar.pro
There is yet another syntax to modify substituted parameters. You can add certain modifiers in parentheses after the opening brace like:
${(modifiers)parameter}
For example, o sorts the words resulting from the expansion:
% echo ${path}
/usr/bin /usr/bin/X11 /etc
% echo ${(o)path}
/etc /usr/bin /usr/bin/X11
One possible source of confusion is the fact that in zsh, the result of parameter substitution is not split into words. Thus, this will not work:
% srcs='glob.c exec.c init.c' % ls $srcs glob.c exec.c init.c not found
This is considered a feature, not a bug. If splitting were done by default, as it is in most other shells, functions like this would not work properly:
$ ll () { ls -F $* }
$ ll 'fuu bar'
fuu not found
bar not found
% ll 'fuu bar'
fuu bar not found
Of course, a hackish workaround is available in sh (and zsh):
% setopt shwordsplit
% ll () { ls -F "$@" }
% ll 'fuu bar'
fuu bar not found
If you like the sh behaviour, zsh can accommodate you:
% ls ${=srcs}
exec.c glob.c init.c
% setopt shwordsplit
% ls $srcs
exec.c glob.c init.c
Another way to get the $srcs trick to work is to use an array:
% unset srcs % srcs=( glob.c exec.c init.c ) % ls $srcs exec.c glob.c init.c
or an alias:
% alias -g SRCS='exec.c glob.c init.c' % ls SRCS exec.c glob.c init.c
Another option that modifies parameter expansion is RCEXPANDPARAM:
% echo foo/$srcs
foo/glob.c exec.c init.c
% setopt rcexpandparam
% echo foo/$srcs
foo/glob.c foo/exec.c foo/init.c
% echo foo/${^srcs}
foo/glob.c foo/exec.c foo/init.c
% echo foo/$^srcs
foo/glob.c foo/exec.c foo/init.c
The shell has many predefined parameters that may be accessed. Here are some examples:
% sleep 10 & [1] 3820 % echo $! 3820 % set a b c % echo $# 3 % echo $ARGC 3 % ( exit 20 ) ; echo $? 20 % false; echo $status 1
($? and $status are equivalent.)
% echo $HOST $HOSTTYPE dendrite sun4 % echo $UID $GID 701 60 % cd /tmp % cd /home % echo $PWD $OLDPWD /home /tmp % ls $OLDPWD/.getwd /tmp/.getwd
~+ and ~- are short for $PWD and $OLDPWD, respectively.
% ls ~-/.getwd /tmp/.getwd % ls -d ~+/learning /home/learning % echo $RANDOM 4880 % echo $RANDOM 11785 % echo $RANDOM 2062 % echo $TTY /dev/ttyp4 % echo $VERSION zsh v2.00.03 % echo $USERNAME pf
The cdpath variable sets the search path for the cd command. If you do not specify . somewhere in the path, it is assumed to be the first component.
% cdpath=( /usr ~ ~/zsh ) % ls /usr 5bin dict lang net sccs sys 5include etc lector nserve services tmp 5lib export lib oed share ucb adm games local old skel ucbinclude bin geac lost+found openwin spool ucblib boot hosts macsyma_417 pat src xpg2bin demo include man princeton stand xpg2include diag kvm mdec pub swap xpg2lib % cd spool /usr/spool % cd bin /usr/bin % cd func ~/func % cd % cd pub % pwd /u/pfalstad/pub % ls -d /usr/pub /usr/pub
PATH and path both set the search path for commands. These two variables are equivalent, except that one is a string and one is an array. If the user modifies PATH, the shell changes path as well, and vice versa.
% PATH=/bin:/usr/bin:/tmp:. % echo $path /bin /usr/bin /tmp . % path=( /usr/bin . /usr/local/bin /usr/ucb ) % echo $PATH /usr/bin:.:/usr/local/bin:/usr/ucb
The same is true of CDPATH and cdpath:
% echo $CDPATH /usr:/u/pfalstad:/u/pfalstad/zsh % CDPATH=/u/subbarao:/usr/src:/tmp % echo $cdpath /u/subbarao /usr/src /tmp
In general, predefined parameters with names in all lowercase are arrays; assignments to them take the form:
name=( elem ... )
Predefined parameters with names in all uppercase are strings. If there is both an array and a string version of the same parameter, the string version is a colon-separated list, like PATH. You can use
% typeset -T FOO foo
to create more of these yourself.
% foo=( a b c ) % echo $FOO a:b:c
HISTFILE is the name of the history file, where the history is saved when a shell exits.
% zsh phoenix% HISTFILE=/tmp/history phoenix% SAVEHIST=20 phoenix% echo foo foo phoenix% date Fri May 24 05:39:35 EDT 1991 phoenix% uptime 5:39am up 4 days, 20:02, 40 users, load average: 2.30, 2.20, 2.00 phoenix% exit % cat /tmp/history HISTFILE=/tmp/history SAVEHIST=20 echo foo date uptime exit % HISTSIZE=3 % history 28 rm /tmp/history 29 HISTSIZE=3 30 history
If you have several instances of zsh running at the same time, like when using the X window system, it might be preferable to append the history of each shell to a file when a shell exits instead of overwriting the old contents of the file. You can get this behaviour by setting the APPENDHISTORY option.
In zsh, if you say
% >file
the command cat is normally assumed:
% >file foo! ^D % cat file foo!
Thus, you can view a file simply by typing:
% <file foo!
However, this is not csh or sh compatible. To correct this, change the value of the parameter NULLCMD, which is cat by default.
% NULLCMD=: % >file % ls -l file -rw-r--r-- 1 pfalstad 0 May 24 05:41 file
If NULLCMD is unset, the shell reports an error if no command is specified (like csh).
% unset NULLCMD % >file zsh: redirection with no command
Actually, READNULLCMD is used whenever you have a null command reading input from a single file. Thus, you can set READNULLCMD to more or less rather than cat. Also, if you set NULLCMD to : for sh compatibility, you can still read files with < file if you leave READNULLCMD set to more.
The default prompt for zsh is:
phoenix% echo $PROMPT %m%#
The %m stands for the short form of the current hostname, and the %# stands for a % or a #, depending on whether the shell is running as root or not. zsh supports many other control sequences in the PROMPT variable.
% PROMPT='%/> ' /u/pfalstad/etc/TeX/zsh> % PROMPT='%~> ' ~/etc/TeX/zsh> % PROMPT='%h %~> ' 6 ~/etc/TeX/zsh>
%h represents the number of current history event.
% PROMPT='%h %~ %M> ' 10 ~/etc/TeX/zsh apple-gunkies.gnu.ai.mit.edu> % PROMPT='%h %~ %m> ' 11 ~/etc/TeX/zsh apple-gunkies> % PROMPT='%h %t> ' 12 6:11am> % PROMPT='%n %w tty%l>' pfalstad Fri 24 ttyp0>
PROMPT2 is used in multiline commands, like for-loops. The %_ escape sequence was made especially for this prompt. It is replaced by the kind of command that is being entered.
% PROMPT2='%_> ' % for i in foo bar for> % echo 'hi quote>
Also available is the RPROMPT parameter. If this is set, the shell puts a prompt on the right side of the screen.
% RPROMPT='%t' % 6:14am % RPROMPT='%~' % ~/etc/TeX/zsh % PROMPT='%l %T %m[%h] ' RPROMPT=' %~' p0 6:15 phoenix[5] ~/etc/TeX/zsh
These special escape sequences can also be used with the -P option to print:
% print -P %h tty%l 15 ttyp1
The POSTEDIT parameter is printed whenever the editor exits. This can be useful for termcap tricks. To highlight the prompt and command line while leaving command output unhighlighted, try this:
% POSTEDIT=`echotc se` % PROMPT='%S%% '
This trick is mostly superseded by the zle_highlight array parameter.
You can specify login or logout events to monitor by setting the watch variable. Normally, this is done by specifying a list of usernames.
% watch=( pfalstad subbarao sukthnkr egsirer )
The log command reports all people logged in that you are watching for.
% log pfalstad has logged on p0 from mickey. pfalstad has logged on p5 from mickey. % ... subbarao has logged on p8 from phoenix. % ... subbarao has logged off p8 from phoenix. % ... sukthnkr has logged on p8 from dew. % ... sukthnkr has logged off p8 from dew.
If you specify hostnames with an @ prepended, the shell will watch for all users logging in from the specified host.
% watch=( @mickey @phoenix ) % log djthongs has logged on q2 from phoenix. pfalstad has logged on p0 from mickey. pfalstad has logged on p5 from mickey.
If you give a tty name with a % prepended, the shell will watch for all users logging in on that tty.
% watch=( %ttyp0 %console ) % log root has logged on console from . pfalstad has logged on p0 from mickey.
The format of the reports may also be changed.
% watch=( pfalstad gettes eps djthongs jcorr bdavis ) % log jcorr has logged on tf from 128.112.176.3:0. jcorr has logged on r0 from 128.112.176.3:0. gettes has logged on p4 from yo:0.0. djthongs has logged on pe from grumpy:0.0. djthongs has logged on q2 from phoenix. bdavis has logged on qd from BRUNO. eps has logged on p3 from csx30:0.0. pfalstad has logged on p0 from mickey. pfalstad has logged on p5 from mickey. % WATCHFMT='%n on tty%l from %M' % log jcorr on ttytf from 128.112.176.3:0. jcorr on ttyr0 from 128.112.176.3:0. gettes on ttyp4 from yo:0.0 djthongs on ttype from grumpy:0.0 djthongs on ttyq2 from phoenix.Princeto bdavis on ttyqd from BRUNO.pppl.gov eps on ttyp3 from csx30:0.0 pfalstad on ttyp0 from mickey.Princeton pfalstad on ttyp5 from mickey.Princeton % WATCHFMT='%n fm %m' % log jcorr fm 128.112.176.3:0 jcorr fm 128.112.176.3:0 gettes fm yo:0.0 djthongs fm grumpy:0.0 djthongs fm phoenix bdavis fm BRUNO eps fm csx30:0.0 pfalstad fm mickey pfalstad fm mickey % WATCHFMT='%n %a at %t %w.' % log jcorr logged on at 3:15pm Mon 20. jcorr logged on at 3:16pm Wed 22. gettes logged on at 6:54pm Wed 22. djthongs logged on at 7:19am Thu 23. djthongs logged on at 7:20am Thu 23. bdavis logged on at 12:40pm Thu 23. eps logged on at 4:19pm Thu 23. pfalstad logged on at 3:39am Fri 24. pfalstad logged on at 3:42am Fri 24.
If you have a .friends file in your home directory, a convenient way to make zsh watch for all your friends is to do this:
% watch=( $(< ~/.friends) ) % echo $watch subbarao maruchck root sukthnkr ...
If watch is set to all, then all users logging in or out will be reported.
Some options have already been mentioned; here are a few more:
Using the AUTOCD option, you can simply type the name of a directory, and it will become the current directory.
% cd / % setopt autocd % bin % pwd /bin % ../etc % pwd /etc
With CDABLEVARS, if the argument to cd is the name of a parameter whose value is a valid directory, it will become the current directory.
% setopt cdablevars % foo=/tmp % cd foo /tmp
CORRECT turns on spelling correction for commands, and the CORRECTALL option turns on spelling correction for all arguments.
% setopt correct % sl zsh: correct `sl' to `ls' [nyae]? y % setopt correctall % ls x.v11r4 zsh: correct `x.v11r4' to `X.V11R4' [nyae]? n /usr/princton/src/x.v11r4 not found % ls /etc/paswd zsh: correct to `/etc/paswd' to `/etc/passwd' [nyae]? y /etc/passwd
If you press y when the shell asks you if you want to correct a word, it will be corrected. If you press n, it will be left alone. Pressing a aborts the command, and pressing e brings the line up for editing again, in case you agree the word is spelled wrong but you don't like the correction.
Normally, a quoted expression may contain a newline:
% echo ' > foo > ' foo %
With CSHJUNKIEQUOTES set, this is illegal, as it is in csh.
% setopt cshjunkiequotes % ls 'foo zsh: unmatched '
GLOBDOTS lets files beginning with a . be matched without explicitly specifying the dot. This can also be specified for a particular pattern by appending (D) to it.
% ls -d *x* Mailboxes % ls -d *x*(D) .exrc .pnewsexpert .xserverrc .mushexpert .xinitrc Mailboxes % setopt globdots % ls -d *x* .exrc .pnewsexpert .xserverrc .mushexpert .xinitrc Mailboxes
HISTIGNOREDUPS prevents the current line from being saved in the history if it is the same as the previous one; HISTIGNORESPACE prevents the current line from being saved if it begins with a space.
% PROMPT='%h> ' 39> setopt histignoredups 40> echo foo foo 41> echo foo foo 41> echo foo foo 41> echo bar bar 42> setopt histignorespace 43> echo foo foo 43> echo fubar fubar 43> echo fubar fubar
IGNOREBRACES turns off csh-style brace expansion.
% echo x{y{z,a},{b,c}d}e
xyze xyae xbde xcde
% setopt ignorebraces
% echo x{y{z,a},{b,c}d}e
x{y{z,a},{b,c}d}e
IGNOREEOF forces the user to type exit or logout, instead of just pressing ^D.
% setopt ignoreeof % ^D zsh: use 'exit' to exit.
INTERACTIVECOMMENTS turns on interactive comments; comments begin with a #.
% setopt interactivecomments % date # this is a comment Fri May 24 06:54:14 EDT 1991
NOBEEP makes sure the shell never beeps.
NOCLOBBER prevents you from accidentally overwriting an existing file.
% setopt noclobber % cat /dev/null >~/.zshrc zsh: file exists: /u/pfalstad/.zshrc
If you really do want to clobber a file, you can use the >! operator. To make things easier in this case, the > is stored in the history list as a >!:
% cat /dev/null >! ~/.zshrc % cat /etc/motd > ~/.zshrc zsh: file exists: /u/pfalstad/.zshrc % !! cat /etc/motd >! ~/.zshrc % ...
RCQUOTES lets you use a more elegant method for including single quotes in a singly quoted string:
% echo '"don'\''t do that."' "don't do that." % echo '"don''t do that."' "dont do that." % setopt rcquotes % echo '"don''t do that."' "don't do that."
Finally, SUNKEYBOARDHACK wins the award for the strangest option. If a line ends with `, and there are an odd number of them on the line, the shell will ignore the trailing `. This is provided for keyboards whose RETURN key is too small, and too close to the ` key.
% setopt sunkeyboardhack % date` Fri May 24 06:55:38 EDT 1991
I (Bas de Bakker) would be happy to receive mail if anyone has any tricks or ideas to add to this document, or if there are some points that could be made clearer or covered more thoroughly. Please notify me of any errors in this document.