ZSHBUILTINS(1)ZSHBUILTINS(1)NAMEzshbuiltins - zsh built-in commands
SHELL BUILTIN COMMANDS
- simple command
See the section `Precommand Modifiers'.
. 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. The exit 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.
If the -s flags is present, define a suffix alias: if the com‐
mand 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, include common problems, see the section
ALIASING in zshmisc(1).
autoload [ {+|-}UXktz ] [ -w ] [ name ... ]
Equivalent to functions -u, with the exception of -X/+X and -w.
The flag -X may be used only inside a shell function, and may
not be followed by a name. 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 func‐
tion remains undefined and marked for autoloading.
The flag +X attempts to load each name as an autoloaded func‐
tion, but does not execute it. The exit status is zero (suc‐
cess) if the function was not previously defined and a defini‐
tion for it was found. This does not replace any existing defi‐
nition 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.
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 in native
or ksh emulation, 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.
bg [ job ... ]
job ... &
Put each specified job in the background, or the current job if
none is specified.
bindkey
See the section `Zle Builtins' in zshzle(1).
break [ n ]
Exit from an enclosing for, while, until, select or repeat loop.
If 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 the section `The zsh/cap Module' in zshmodules(1).
cd [ -qsLP ] [ arg ]
cd [ -qsLP ] old new
cd [ -qsLP ] {+|-}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 value of $OLDPWD, 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 directo‐
ries 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.
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 -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 environ‐
ment 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 the section `The zsh/clone Module' in zshmodules(1).
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 the section `Precommand Modifiers'.
comparguments
See the section `The zsh/computil Module' in zshmodules(1).
compcall
See the section `The zsh/compctl Module' in zshmodules(1).
compctl
See the section `The zsh/compctl Module' in zshmodules(1).
compdescribe
See the section `The zsh/computil Module' in zshmodules(1).
compfiles
See the section `The zsh/computil Module' in zshmodules(1).
compgroups
See the section `The zsh/computil Module' in zshmodules(1).
compquote
See the section `The zsh/computil Module' in zshmodules(1).
comptags
See the section `The zsh/computil Module' in zshmodules(1).
comptry
See the section `The zsh/computil Module' in zshmodules(1).
compvalues
See the section `The zsh/computil Module' in zshmodules(1).
continue [ n ]
Resume the next iteration of the enclosing for, while, until,
select or repeat loop. If 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 speci‐
fied, 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 of using ~
expressions.
-p print directory entries one per line.
-v number the directories in the stack when printing.
disable [ -afmrs ] name ...
Temporarily disable the named hash table elements. 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 pat‐
terns (which should be quoted to prevent them from undergoing
filename expansion), and all hash table elements from the corre‐
sponding hash table matching these patterns are disabled. Dis‐
abled objects can be enabled with the enable command.
disown [ 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.
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 final newline
\e escape
\f form feed
\n linefeed (newline)
\r carriage return
\t horizontal tab
\v vertical tab
\\ backslash
\0NNN character code in octal
\xNN character code in hexadecimal
\uNNNN unicode character code in hexadecimal
\UNNNNNNNN
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.
echotc See the section `The zsh/termcap Module' in zshmodules(1).
echoti See the section `The zsh/terminfo Module' in zshmodules(1).
emulate [ -LR ] [ {zsh|sh|ksh|csh} [ -c arg ] ]
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 the section `Compatibil‐
ity' in zshmisc(1) .
If the -R option is given, all options are reset to their
default value corresponding to the specified emulation mode,
except for certain options describing the interactive environ‐
ment; otherwise, only those options likely to cause portability
problems in scripts and functions are altered. If the -L option
is given, the options LOCAL_OPTIONS and LOCAL_TRAPS will be set
as well, causing the effects of the emulate command and any
setopt and trap commands to be local to the immediately sur‐
rounding shell function, if any; normally these options are
turned off in all emulation modes except ksh. The -L and -c are
mutually exclusive.
If -c arg is given, evaluate arg while the requested emulation
is temporarily in effect. The emulation and all options will be
restored to their original values before emulate returns. The
-R flag may be used.
Use of -c enables `sticky' emulation mode for functions defined
within the evaluated expression: the emulation mode is associ‐
ated thereafter with the function so that whenever the function
is executed the emulation (respecting the -R flag, if present)
and all options are set before entry to the function, and
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).
For example:
emulate sh -c 'fni() { setopt cshnullglob; }
fno() { fni; }'
fno
The two functions fni and fno are defined with sticky sh emula‐
tion. fno is then executed, causing options associated with
emulations to be set to their values in sh. fni then calls fno;
because fno 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 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 suit‐
able 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 exam‐
ple, 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 flag to emulate corre‐
sponds to different sticky emulation modes, so for exam‐
ple `emulate sh -c', `emulate -R sh -c' and `emulate csh
-c' are treated as three distinct sticky emulations.
enable [ -afmrs ] name ...
Enable the named hash table elements, presumably disabled ear‐
lier 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 pat‐
terns (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 com‐
mand.
eval [ arg ... ]
Read the arguments as input to the shell and execute the result‐
ing 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 ] simple command
Replace the current shell with an external command rather than
forking. 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 exe‐
cuted. See the section `Precommand Modifiers'.
exit [ n ]
Exit the shell with the exit status specified by n; if none is
specified, use the exit status from the last command executed.
An EOF condition will also cause the shell to exit, unless the
IGNORE_EOF option is set.
export [ name[=value] ... ]
The specified names are marked for automatic export to the envi‐
ronment of subsequently executed commands. Equivalent to type‐
set -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 ] [ -m match ] [ old=new ... ] [ first [ last ] ]
fc -l [ -nrdfEiD ] [ -t timefmt ] [ -m match ]
[ old=new ... ] [ first [ last ] ]
fc -p [ -a ] [ filename [ histsize [ savehistsize ] ] ]
fc -P
fc -ARWI [ filename ]
Select a range of commands 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 commands.
If the -l flag is given, the resulting commands are listed on
standard output. If the -m flag is also given the first argu‐
ment is taken as a pattern (should be quoted) and only the his‐
tory events matching this pattern will be shown. Otherwise the
editor program ename is invoked on a file containing these his‐
tory events. If ename 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.
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 spec‐
ified, it will be set to first, or to -1 if the -l flag is
given.
The flag -r reverses the order of the commands and the flag -n
suppresses command numbers when listing.
Also when listing,
-d prints timestamps for each command
-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 exten‐
sions described for the %D{string} prompt format in the
section EXPANSION OF PROMPT SEQUENCES in zshmisc(1). The
resulting formatted string must be no more than 256 char‐
acters 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 speci‐
fied, this history list will be automatically popped when the
current function scope is exited, which is a much better solu‐
tion 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 appro‐
priately, 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 dec‐
larations 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 his‐
tory 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 [ {+|-}EFHghlprtux ] [ -LRZ [ n ]] [ name[=value] ... ]
Equivalent to typeset -E, except that options irrelevant to
floating point numbers are not permitted.
functions [ {+|-}UXkmtuz ] [ name ... ]
functions -M mathfn [ min [ max [ shellfn ] ] ]
functions -M [ -m pattern ... ]
functions +M [ -m ] mathfn
Equivalent to typeset -f, with the exception of the -M option.
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 the section `Arithmetic Evaluation' in zshmisc(1). 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 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 mathe‐
matical function call. The result of the last arithmetical
expression evaluated inside the shell function (even if it is a
form that normally only returns a status) gives the result of
the mathematical function.
functions -M with no arguments lists all such user-defined func‐
tions 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).
For example, the following prints the cube of 3:
zmath_cube() { (( $1 * $1 * $1 )) }
functions -M cube 1 1 zmath_cube
print $(( cube(3) ))
getcap See the section `The zsh/cap Module' in zshmodules(1).
getln [ -AclneE ] name ...
Read the top value from the buffer stack and put it in the shell
parameter name. Equivalent to read -zr.
getopts optstring name [ arg ... ]
Checks the args for legal options. If the args are omitted, use
the positional parameters. 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 is expected to have an argument. The options
can be separated from the argument by blanks.
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.
The first option to be examined may be changed by explicitly
assigning to OPTIND. OPTIND has an initial value of 1, and is
normally reset to 1 upon exit from a shell function. 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 option 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.
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 com‐
mand 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.
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 imme‐
diately. For the command hash table this hashes all the abso‐
lute 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.
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 [ {+|-}Hghilprtux ] [ -LRZ [ 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 fea‐
ture is typically used by daemons, to indicate their state.
kill [ -s signal_name | -n signal_number | -sig ] job ...
kill -l [ sig ... ]
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.
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.
let arg ...
Evaluate each arg as an arithmetic expression. See the section
`Arithmetic Evaluation' in zshmisc(1) 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 cur‐
rent 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 imme‐
diately if it detects a badly formed argument. However, if it
fails to set a limit for some other reason it will continue try‐
ing 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 opera‐
tions.
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.
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.
resident
Maximum resident set size.
sigpending
Maximum number of pending signals.
sockbufsize
Maximum size of all socket buffers.
stacksize
Maximum stack size for each process.
vmemorysize
Maximum amount of virtual memory.
Which of these resource limits are available depends on the sys‐
tem. 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:
nh hours
nk kilobytes (default)
nm megabytes or minutes
[mm:]ss
minutes and seconds
local [ {+|-}AEFHUahlprtux ] [ -LRZi [ n ]] [ name[=value] ] ...
Same as typeset, except that the options -g, and -f are not per‐
mitted. In this case the -x option does not force the use of
-g, i.e. exported variables will be local to functions.
log List all users currently logged in who are affected by the cur‐
rent setting of the watch parameter.
logout [ n ]
Same as exit, except that it only works in a login shell.
noglob simple command
See the section `Precommand Modifiers'.
popd [ [-q] {+|-}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. 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 [ -abcDilmnNoOpPrsz ] [ -u n ] [ -f format ] [ -C cols ]
[ -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' metafies the
character x (sets the highest bit), `\C-x' produces a control
character (`\C-@' and `\C-?' give the characters NUL and
delete), 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 bind‐
key command, see zshzle(1).
-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 directory names, replacing pre‐
fixes with ~ expressions, as appropriate.
-i If given together with -o or -O, sorting is performed
case-independently.
-l Print the arguments separated by newlines instead of spa‐
ces.
-m Take the first argument as a pattern (should be quoted),
and remove it from the argument list together with subse‐
quent 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.
-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 EXPANSION OF PROMPT
SEQUENCES in zshmisc(1)).
-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.
-u n Print the arguments to file descriptor n.
-z Push the arguments onto the editing buffer stack, sepa‐
rated 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 format [ arg ... ]
Print the arguments according to the format specification. For‐
matting rules are the same as used in C. The same escape
sequences as for echo are recognised in the format. All C con‐
version specifications ending in one of csdiouxXeEfgGn are han‐
dled. 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 the section `Arithmetic Evaluation' in zsh‐
misc(1) 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 rec‐
ommended 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 speci‐
fied as the argument.
pushd [ -qsLP ] [ arg ]
pushd [ -qsLP ] old new
pushd [ -qsLP ] {+|-}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 inter‐
preted 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 direc‐
tory 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.
Currently does not work with the -q option.
-q Read only one character from the terminal and set name to
`y' if this character was `y' or `Y' and to `n' other‐
wise. With this flag set the return status is zero only
if the character was `y' or `Y'. Note that this always
reads from the terminal, even if used with the -p or -u
or -z flags or with redirected input. 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 ter‐
minal 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(1)). This flag is
ignored when the -k or -q flags are present.
-e
-E The input read is printed (echoed) to the standard out‐
put. 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 com‐
pctl). 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.
-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 pro‐
cessing 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 charac‐
ter. 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 stan‐
dard 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. Other‐
wise 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.
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 n. If n is omitted,
the return status is that of the last command executed.
If return was executed from a trap in a TRAPNAL 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 pro‐
cessing; with a non-zero status, the shell will behave as inter‐
rupted 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 the section `The zsh/sched Module' in zshmodules(1).
set [ {+|-}options | {+|-}o [ option_name ] ] ... [ {+|-}A [ name ] ] [
arg ... ]
Set the options for the shell and/or set the positional parame‐
ters, 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(1). Flags may be
specified by name using the -o option. If no option name is sup‐
plied 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 speci‐
fied, 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 the section `The zsh/cap Module' in zshmodules(1).
setopt [ {+|-}options | {+|-}o option_name ] [ 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 dif‐
ferences from the default options for the current emulation (the
default emulation being native zsh, shown as <Z> in zshop‐
tions(1)). 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 expan‐
sion), and all options with names matching these patterns are
set.
shift [ 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.
source file [ arg ... ]
Same as `.', except that the current directory is always
searched and is always searched first, before directories in
$path.
stat See the section `The zsh/stat Module' in zshmodules(1).
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 the section `Conditional
Expressions'). The main differences between the conditional
expression syntax and the test and [ builtins are: these com‐
mands 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 ambigui‐
ties 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 argu‐
ments (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 the section SIMPLE COMMANDS
& PIPELINES in zshmisc(1). 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(1). 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 parame‐
ter 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 execu‐
tion 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.
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 dif‐
ferent from those defined as `TRAPNAL () { ... }', as the latter
have their own function environment (line numbers, local vari‐
ables, 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 $LINENO; }
will always print the number zero.
Alternative signal names are allowed as described under kill
above. Defining a trap under either name causes any trap under
an alternative name to be removed. However, it is recommended
that for consistency users stick exclusively to one name or
another.
true [ arg ... ]
Do nothing and return an exit status of 0.
ttyctl -fu
The -f option freezes the tty, and -u unfreezes it. When the
tty is frozen, no changes made to the tty settings by external
programs will be honored by the shell, except for changes in the
size of the screen; the shell will simply reset the settings to
their previous values as soon as each command exits or is sus‐
pended. Thus, stty and similar programs have no effect when the
tty is frozen. Without options it reports whether the terminal
is frozen or not.
type [ -wfpams ] name ...
Equivalent to whence -v.
typeset [ {+|-}AEFHUafghklprtuxmz ] [ -LRZi [ n ]] [ name[=value] ... ]
typeset -T [ {+|-}Urux ] [ -LRZ [ n ]] SCALAR[=value] array [ sep ]
Set or display attributes and values for shell parameters.
A parameter is created for each name that does not already refer
to one. When inside a function, a new parameter is created for
every name (even those that already exist), and is unset again
when the function completes. See `Local Parameters' in zsh‐
param(1). The same rules apply to special shell parameters,
which retain their special attributes when made local.
For each name=value assignment, the parameter name is set to
value. Note that arrays currently cannot be assigned in typeset
expressions, only scalars and integers. Unless the option
KSH_TYPESET is set, normal expansion rules apply to assignment
arguments, so value may be split into separate words; if the
option is set, assignments which can be recognised when expan‐
sion is performed are treated as single words. For example the
command typeset vbl=$(echo one two) is treated as having one
argument if KSH_TYPESET is set, but otherwise is treated as hav‐
ing the two arguments vbl=one and two.
If the shell option TYPESET_SILENT is not set, for each remain‐
ing name that refers to a parameter that is 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 the -p option is given, parameters and values are printed in
the form of a typeset command and an assignment (which will be
printed separately for arrays and associative arrays), regard‐
less of other flags and options. Note that the -h flag on
parameters is respected; no value will be shown for these param‐
eters.
If the -T option is given, two or three arguments must be
present (an exception is that zero arguments are allowed to show
the list of parameters created in this fashion). The first two
are the name of a scalar and 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. Only the scalar parameter may be
assigned an initial value. Both the scalar and the array may
otherwise 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, or converting the type of one
of them with another typeset command; +T does not work, assign‐
ing 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).
The -g (global) flag is treated specially: it 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 list‐
ing existing parameters, nor does the flag +g have any effect
except in combination with -m (see below).
If no name is present, the names and values of all parameters
are printed. In this case the attribute flags restrict the dis‐
play 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. Also, if the last option is the word `+', then
names are printed but values are not.
If the -m flag is given the name arguments are taken as patterns
(which should be quoted). With no attribute flags, all parame‐
ters (or functions with the -f flag) with matching names are
printed (the shell option TYPESET_SILENT is not used in this
case). Note that -m is ignored if no patterns are given. If
the +g flag is combined with -m, a new local parameter is cre‐
ated for every matching parameter that is not already local.
Otherwise -m applies all other flags or assignments to the
existing parameters. Except when assignments are made with
name=value, using +m forces the matching parameters to be
printed, even inside a function.
If no attribute flags are given and either no -m flag is present
or the +m form was used, each parameter name printed is preceded
by a list of the attributes of that parameter (array, associa‐
tion, exported, integer, readonly). 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.
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
`Array Parameters' in zshparam(1).
-L Left justify and remove leading blanks from value. 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 parame‐
ters, 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 multi‐
byte 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
`Parameter Expansion Flags' in zshexpn(1).
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 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 com‐
bined 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 colon-separated special parameters like
PATH or FIGNORE, etc. This flag has a different meaning
when used with -f; see below.
-Z Specially handled if set along with the -L flag. Other‐
wise, 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 not be assigned to in
the typeset statement. 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, -k, -u, -U and -z. The flag -t turns on execu‐
tion tracing for this function. 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. The fpath parameter will be searched to find
the function definition when the function is first refer‐
enced; see the section `Functions'. The -k and -z flags
make the function be loaded using ksh-style or zsh-style
autoloading respectively. If neither is given, the set‐
ting of the KSH_AUTOLOAD option determines how the func‐
tion is loaded.
-h Hide: only useful for special parameters (those marked
`<S>' in the table in zshparam(1)), and for local parame‐
ters 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 contain‐
ing `typeset PATH' will create an ordinary local parame‐
ter 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 (currently 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 dis‐
play for such parameters is always as if the `+' flag had
been given. Use of the parameter is in other respects
normal, and the option does not apply if 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-spe‐
cial parameters.
-i 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 Use an internal double-precision floating point represen‐
tation. On output the variable will be converted to sci‐
entific notation. If n is nonzero it defines the number
of significant figures to display; the default is ten.
-F Use an internal double-precision floating point represen‐
tation. 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.
-t Tags the named parameters. Tags have no special meaning
to the shell. This 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 a different meaning when used with -f; see
above.
-x Mark for automatic export to the environment of subse‐
quently 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 com‐
patibility with previous versions of zsh.
ulimit [ [ -SHacdfilmnpqstvx | -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 the value `unlimited'. 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 values are printed the
limit name and unit is printed before each value.
When looping over multiple resources, the shell will abort imme‐
diately if it detects a badly formed argument. However, if it
fails to set a limit for some other reason it will continue try‐
ing to set the remaining limits.
-a Lists all of the current resource limits.
-c 512-byte blocks on the size of core dumps.
-d K-bytes on the size of the data segment.
-f 512-byte blocks on the size of files written.
-i The number of pending signals.
-l K-bytes on the size of locked-in memory.
-m K-bytes on the size of physical memory.
-n open file descriptors.
-q Bytes in POSIX message queues.
-s K-bytes on the size of the stack.
-t CPU seconds to be used.
-u processes available to the user.
-v K-bytes on the size of virtual memory. On some systems
this refers to the limit called `address space'.
-x The number of locks on files.
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 corre‐
spond 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 com‐
piled 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 chmod(1). 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 permis‐
sions you specify are those which are to be allowed (not denied)
to the users specified.
unalias
Same as unhash -a.
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 privi‐
leges, the hard resource limit for each resource is removed.
The resources of the shell process are only changed if the -s
flag is given.
unset [ -fmv ] 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 sub‐
script 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.
unset -f is equivalent to unfunction.
unsetopt [ {+|-}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 pat‐
terns), and all options with names matching these patterns are
unset.
vared See the section `Zle Builtins' in zshzle(1).
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.
whence [ -vcwfpams ] name ...
For each name, indicate how it would be interpreted if used as a
command name.
-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.
-m The arguments are taken as patterns (should be quoted),
and the information is displayed for each command match‐
ing one of these patterns.
-s If a pathname contains symlinks, print the symlink-free
pathname as well.
where [ -wpms ] name ...
Equivalent to whence -ca.
which [ -wpams ] 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 execution 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 com‐
piled 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
the section `Autoloading Functions' in zshfunc(1) for a descrip‐
tion 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 defini‐
tion files for those functions, if found, are compiled into
file. If both -c and -a are given, names of both defined func‐
tions 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 addi‐
tional functions defined in the file, and any other initializa‐
tion 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.
The third form, with the -t option, examines an existing com‐
piled file. Without further arguments, the names of the origi‐
nal 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, conse‐
quently 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 com‐
piled 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 com‐
piled 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 com‐
piled 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 the section `The zsh/zutil Module' in zshmodules(1).
zftp See the section `The zsh/zftp Module' in zshmodules(1).
zle See the section `Zle Builtins' in zshzle(1).
zmodload [ -dL ] [ ... ]
zmodload -F [ -lLme -P param ] module [+-]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 mod‐
ules are printed. The -L option causes this list to be in the
form of a series of zmodload commands. Forms with arguments
are:
zmodload [ -i ] 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 zmod‐
load detects an inconsistency, such as an invalid module
name or circular dependency list, the current code block
is aborted. Hence `zmodload module 2>/dev/null' is suf‐
ficient to test whether a module is available. 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 com‐
mand 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.
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 filesys‐
tem. 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 mod‐
ule will not be loaded if its boot function fails. Simi‐
larly a module can only be unloaded if its cleanup func‐
tion runs successfully.
zmodload -F [ -almLe -P param ] module [+-]feature...
zmodload -F allows more selective control over the fea‐
tures 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 fea‐
tures 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, parame‐
ters and math functions; these are indicated by the pre‐
fix `b:', `c:' (`C:' for an infix condition), `p:' and
`f:', respectively, followed by the name that the corre‐
sponding 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 pre‐
fix.
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 fea‐
tures to be set to their current state is shown. If one
of these combinations is given 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 dis‐
abled 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 mod‐
ule 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 pro‐
vided and in the given state. If the tests on all fea‐
tures 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 fea‐
tures 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 argu‐
ment.
With -d and one argument, all dependencies for that mod‐
ule 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 pos‐
sible 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 subse‐
quently 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 condi‐
tions.
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 corre‐
sponding 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 list‐
ing, 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 inde‐
pendent of whether the name resolved is actually loaded
as a module: while the alias exists, loading and unload‐
ing 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 redefin‐
ing 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 avail‐
able 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 the section `The zsh/zutil Module' in zshmodules(1).
zprof See the section `The zsh/zprof Module' in zshmodules(1).
zpty See the section `The zsh/zpty Module' in zshmodules(1).
zregexparse
See the section `The zsh/zutil Module' in zshmodules(1).
zsocket
See the section `The zsh/net/socket Module' in zshmodules(1).
zstyle See the section `The zsh/zutil Module' in zshmodules(1).
ztcp See the section `The zsh/net/tcp Module' in zshmodules(1).
zsh 4.3.10 June 1, 2009 ZSHBUILTINS(1)
