Provided by: zsh-common_5.9-6ubuntu2_all 
NAME
zshbuiltins - zsh built-in commands
SHELL BUILTIN COMMANDS
Some shell builtin commands take options as described in individual entries; these are often referred to
in the list below as `flags' to avoid confusion with shell options, which may also have an effect on the
behaviour of builtin commands. In this introductory section, `option' always has the meaning of an
option to a command that should be familiar to most command line users.
Typically, options are single letters preceded by a hyphen (-). Options that take an argument accept it
either immediately following the option letter or after white space, for example `print -C3 {1..9}' or
`print -C 3 {1..9}' are equivalent. Arguments to options are not the same as arguments to the command;
the documentation indicates which is which. Options that do not take an argument may be combined in a
single word, for example `print -rca -- *' and `print -r -c -a -- *' are equivalent.
Some shell builtin commands also take options that begin with `+' instead of `-'. The list below makes
clear which commands these are.
Options (together with their individual arguments, if any) must appear in a group before any non-option
arguments; once the first non-option argument has been found, option processing is terminated.
All builtin commands other than `echo' and precommand modifiers, even those that have no options, can be
given the argument `--' to terminate option processing. This indicates that the following words are
non-option arguments, but is otherwise ignored. This is useful in cases where arguments to the command
may begin with `-'. For historical reasons, most builtin commands (including `echo') also recognize a
single `-' in a separate word for this purpose; note that this is less standard and use of `--' is
recommended.
- simple command
See the section `Precommand Modifiers' in zshmisc(1).
. file [ arg ... ]
Read commands from file and execute them in the current shell environment.
If file does not contain a slash, or if PATH_DIRS is set, the shell looks in the components of
$path to find the directory containing file. Files in the current directory are not read unless
`.' appears somewhere in $path. If a file named `file.zwc' is found, is newer than file, and is
the compiled form (created with the zcompile builtin) of file, then commands are read from that
file instead of file.
If any arguments arg are given, they become the positional parameters; the old positional
parameters are restored when the file is done executing. However, if no arguments are given, the
positional parameters remain those of the calling context, and no restoring is done.
If file was not found the return status is 127; if file was found but contained a syntax error the
return status is 126; else the return status is the exit status of the last command executed.
: [ arg ... ]
This command does nothing, although normal argument expansions is performed which may have effects
on shell parameters. A zero exit status is returned.
alias [ {+|-}gmrsL ] [ name[=value] ... ]
For each name with a corresponding value, define an alias with that value. A trailing space in
value causes the next word to be checked for alias expansion. If the -g flag is present, define a
global alias; global aliases are expanded even if they do not occur in command position:
% perldoc --help 2>&1 | grep 'built-in functions'
-f Search Perl built-in functions
% alias -g HG='--help 2>&1 | grep'
% perldoc HG 'built-in functions'
-f Search Perl built-in functions
If the -s flag is present, define a suffix alias: if the command word on a command line is in the
form `text.name', where text is any non-empty string, it is replaced by the text `value
text.name'. Note that name is treated as a literal string, not a pattern. A trailing space in
value is not special in this case. For example,
alias -s ps='gv --'
will cause the command `*.ps' to be expanded to `gv -- *.ps'. As alias expansion is carried out
earlier than globbing, the `*.ps' will then be expanded. Suffix aliases constitute a different
name space from other aliases (so in the above example it is still possible to create an alias for
the command ps) and the two sets are never listed together.
For each name with no value, print the value of name, if any. With no arguments, print all
currently defined aliases other than suffix aliases. If the -m flag is given the arguments are
taken as patterns (they should be quoted to preserve them from being interpreted as glob
patterns), and the aliases matching these patterns are printed. When printing aliases and one of
the -g, -r or -s flags is present, restrict the printing to global, regular or suffix aliases,
respectively; a regular alias is one which is neither a global nor a suffix alias. Using `+'
instead of `-', or ending the option list with a single `+', prevents the values of the aliases
from being printed.
If the -L flag is present, then print each alias in a manner suitable for putting in a startup
script. The exit status is nonzero if a name (with no value) is given for which no alias has been
defined.
For more on aliases, include common problems, see the section ALIASING in zshmisc(1).
autoload [ {+|-}RTUXdkmrtWz ] [ -w ] [ name ... ]
See the section `Autoloading Functions' in zshmisc(1) for full details. The fpath parameter will
be searched to find the function definition when the function is first referenced.
If name consists of an absolute path, the function is defined to load from the file given
(searching as usual for dump files in the given location). The name of the function is the
basename (non-directory part) of the file. It is normally an error if the function is not found
in the given location; however, if the option -d is given, searching for the function defaults to
$fpath. If a function is loaded by absolute path, any functions loaded from it that are marked
for autoload without an absolute path have the load path of the parent function temporarily
prepended to $fpath.
If the option -r or -R is given, the function is searched for immediately and the location is
recorded internally for use when the function is executed; a relative path is expanded using the
value of $PWD. This protects against a change to $fpath after the call to autoload. With -r, if
the function is not found, it is silently left unresolved until execution; with -R, an error
message is printed and command processing aborted immediately the search fails, i.e. at the
autoload command rather than at function execution..
The flag -X may be used only inside a shell function. It causes the calling function to be marked
for autoloading and then immediately loaded and executed, with the current array of positional
parameters as arguments. This replaces the previous definition of the function. If no function
definition is found, an error is printed and the function remains undefined and marked for
autoloading. If an argument is given, it is used as a directory (i.e. it does not include the
name of the function) in which the function is to be found; this may be combined with the -d
option to allow the function search to default to $fpath if it is not in the given location.
The flag +X attempts to load each name as an autoloaded function, but does not execute it. The
exit status is zero (success) if the function was not previously defined and a definition for it
was found. This does not replace any existing definition of the function. The exit status is
nonzero (failure) if the function was already defined or when no definition was found. In the
latter case the function remains undefined and marked for autoloading. If ksh-style autoloading
is enabled, the function created will contain the contents of the file plus a call to the function
itself appended to it, thus giving normal ksh autoloading behaviour on the first call to the
function. If the -m flag is also given each name is treated as a pattern and all functions
already marked for autoload that match the pattern are loaded.
With the -t flag, turn on execution tracing; with -T, turn on execution tracing only for the
current function, turning it off on entry to any called functions that do not also have tracing
enabled.
With the -U flag, alias expansion is suppressed when the function is loaded.
With the -w flag, the names are taken as names of files compiled with the zcompile builtin, and
all functions defined in them are marked for autoloading.
The flags -z and -k mark the function to be autoloaded using the zsh or ksh style, as if the
option KSH_AUTOLOAD were unset or were set, respectively. The flags override the setting of the
option at the time the function is loaded.
Note that the autoload command makes no attempt to ensure the shell options set during the loading
or execution of the file have any particular value. For this, the emulate command can be used:
emulate zsh -c 'autoload -Uz func'
arranges that when func is loaded the shell is in native zsh emulation, and this emulation is also
applied when func is run.
Some of the functions of autoload are also provided by functions -u or functions -U, but autoload
is a more comprehensive interface.
bg [ job ... ]
job ... &
Put each specified job in the background, or the current job if none is specified.
bindkey
See the section `Zle Builtins' in zshzle(1).
break [ n ]
Exit from an enclosing for, while, until, select or repeat loop. If an arithmetic expression n is
specified, then break n levels instead of just one.
builtin name [ args ... ]
Executes the builtin name, with the given args.
bye Same as exit.
cap See 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 previous directory.
Otherwise, if arg begins with a slash, attempt to change to the directory given by arg.
If arg does not begin with a slash, the behaviour depends on whether the current directory `.'
occurs in the list of directories contained in the shell parameter cdpath. If it does not, first
attempt to change to the directory arg under the current directory, and if that fails but cdpath
is set and contains at least one element attempt to change to the directory arg under each
component of cdpath in turn until successful. If `.' occurs in cdpath, then cdpath is searched
strictly in order so that `.' is only tried at the appropriate point.
The order of testing cdpath is modified if the option POSIX_CD is set, as described in the
documentation for the option.
If no directory is found, the option CDABLE_VARS is set, and a parameter named arg exists whose
value begins with a slash, treat its value as the directory. In that case, the parameter is added
to the named directory hash table.
The second form of cd substitutes the string new for the string old in the name of the current
directory, and tries to change to this new directory.
The third form of cd extracts an entry from the directory stack, and changes to that directory.
An argument of the form `+n' identifies a stack entry by counting from the left of the list shown
by the dirs command, starting with zero. An argument of the form `-n' counts from the right. If
the PUSHD_MINUS option is set, the meanings of `+' and `-' in this context are swapped. If the
POSIX_CD option is set, this form of cd is not recognised and will be interpreted as the first
form.
If the -q (quiet) option is specified, the hook function chpwd and the functions in the array
chpwd_functions are not called. This is useful for calls to cd that do not change the environment
seen by an interactive user.
If the -s option is specified, cd refuses to change the current directory if the given pathname
contains symlinks. If the -P option is given or the CHASE_LINKS option is set, symbolic links are
resolved to their true values. If the -L option is given symbolic links are retained in the
directory (and not resolved) regardless of the state of the CHASE_LINKS option.
chdir Same as cd.
clone See 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' in zshmisc(1).
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 an
arithmetic expression n is specified, break out of n-1 loops and resume at the nth enclosing loop.
declare
Same as typeset.
dirs [ -c ] [ arg ... ]
dirs [ -lpv ]
With no arguments, print the contents of the directory stack. Directories are added to this stack
with the pushd command, and removed with the cd or popd commands. If arguments are specified,
load them onto the directory stack, replacing anything that was there, and push the current
directory onto the stack.
-c clear the directory stack.
-l print directory names in full instead of using of using ~ expressions (see Dynamic and
Static named directories in zshexpn(1)).
-p print directory entries one per line.
-v number the directories in the stack when printing.
disable [ -afmprs ] name ...
Temporarily disable the named hash table elements or patterns. The default is to disable builtin
commands. This allows you to use an external command with the same name as a builtin command.
The -a option causes disable to act on regular or global aliases. The -s option causes disable to
act on suffix aliases. The -f option causes disable to act on shell functions. The -r options
causes disable to act on reserved words. Without arguments all disabled hash table elements from
the corresponding hash table are printed. With the -m flag the arguments are taken as patterns
(which should be quoted to prevent them from undergoing filename expansion), and all hash table
elements from the corresponding hash table matching these patterns are disabled. Disabled objects
can be enabled with the enable command.
With the option -p, name ... refer to elements of the shell's pattern syntax as described in the
section `Filename Generation'. Certain elements can be disabled separately, as given below.
Note that patterns not allowed by the current settings for the options EXTENDED_GLOB, KSH_GLOB and
SH_GLOB are never enabled, regardless of the setting here. For example, if EXTENDED_GLOB is not
active, the pattern ^ is ineffective even if `disable -p "^"' has not been issued. The list below
indicates any option settings that restrict the use of the pattern. It should be noted that
setting SH_GLOB has a wider effect than merely disabling patterns as certain expressions, in
particular those involving parentheses, are parsed differently.
The following patterns may be disabled; all the strings need quoting on the command line to
prevent them from being interpreted immediately as patterns and the patterns are shown below in
single quotes as a reminder.
'?' The pattern character ? wherever it occurs, including when preceding a parenthesis with
KSH_GLOB.
'*' The pattern character * wherever it occurs, including recursive globbing and when preceding
a parenthesis with KSH_GLOB.
'[' Character classes.
'<' (NO_SH_GLOB)
Numeric ranges.
'|' (NO_SH_GLOB)
Alternation in grouped patterns, case statements, or KSH_GLOB parenthesised expressions.
'(' (NO_SH_GLOB)
Grouping using single parentheses. Disabling this does not disable the use of parentheses
for KSH_GLOB where they are introduced by a special character, nor for glob qualifiers (use
`setopt NO_BARE_GLOB_QUAL' to disable glob qualifiers that use parentheses only).
'~' (EXTENDED_GLOB)
Exclusion in the form A~B.
'^' (EXTENDED_GLOB)
Exclusion in the form A^B.
'#' (EXTENDED_GLOB)
The pattern character # wherever it occurs, both for repetition of a previous pattern and
for indicating globbing flags.
'?(' (KSH_GLOB)
The grouping form ?(...). Note this is also disabled if '?' is disabled.
'*(' (KSH_GLOB)
The grouping form *(...). Note this is also disabled if '*' is disabled.
'+(' (KSH_GLOB)
The grouping form +(...).
'!(' (KSH_GLOB)
The grouping form !(...).
'@(' (KSH_GLOB)
The grouping form @(...).
disown [ 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 subsequent characters and 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.
Note that for standards compliance a double dash does not terminate option processing; instead, it
is printed directly. However, a single dash does terminate option processing, so the first dash,
possibly following options, is not printed, but everything following it is printed as an argument.
The single dash behaviour is different from other shells. For a more portable way of printing
text, see printf, and for a more controllable way of printing text within zsh, see print.
echotc See the section `The zsh/termcap Module' in zshmodules(1).
echoti See the section `The zsh/terminfo Module' in zshmodules(1).
emulate [ -lLR ] [ {zsh|sh|ksh|csh} [ flags ... ] ]
Without any argument print current emulation mode.
With single argument set up zsh options to emulate the specified shell as much as possible. csh
will never be fully emulated. If the argument is not one of the shells listed above, zsh will be
used as a default; more precisely, the tests performed on the argument are the same as those used
to determine the emulation at startup based on the shell name, see the section COMPATIBILITY in
zsh(1) . In addition to setting shell options, the command also restores the pristine state of
pattern enables, as if all patterns had been enabled using enable -p.
If the emulate command occurs inside a function that has been marked for execution tracing with
functions -t then the xtrace option will be turned on regardless of emulation mode or other
options. Note that code executed inside the function by the ., source, or eval commands is not
considered to be running directly from the function, hence does not provoke this behaviour.
If the -R switch is given, all settable options are reset to their default value corresponding to
the specified emulation mode, except for certain options describing the interactive environment;
otherwise, only those options likely to cause portability problems in scripts and functions are
altered. If the -L switch is given, the options LOCAL_OPTIONS, LOCAL_PATTERNS and LOCAL_TRAPS
will be set as well, causing the effects of the emulate command and any setopt, disable -p or
enable -p, and trap commands to be local to the immediately surrounding shell function, if any;
normally these options are turned off in all emulation modes except ksh. The -L switch is mutually
exclusive with the use of -c in flags.
If there is a single argument and the -l switch is given, the options that would be set or unset
(the latter indicated with the prefix `no') are listed. -l can be combined with -L or -R and the
list will be modified in the appropriate way. Note the list does not depend on the current
setting of options, i.e. it includes all options that may in principle change, not just those that
would actually change.
The flags may be any of the invocation-time flags described in the section INVOCATION in zsh(1),
except that `-o EMACS' and `-o VI' may not be used. Flags such as `+r'/`+o RESTRICTED' may be
prohibited in some circumstances.
If -c arg appears in flags, arg is evaluated while the requested emulation is temporarily in
effect. In this case the emulation mode and all options are restored to their previous values
before emulate returns. The -R switch may precede the name of the shell to emulate; note this has
a meaning distinct from including -R in flags.
Use of -c enables `sticky' emulation mode for functions defined within the evaluated expression:
the emulation mode is associated thereafter with the function so that whenever the function is
executed the emulation (respecting the -R switch, if present) and all options are set (and pattern
disables cleared) before entry to the function, and the state is restored after exit. If the
function is called when the sticky emulation is already in effect, either within an `emulate shell
-c' expression or within another function with the same sticky emulation, entry and exit from the
function do not cause options to be altered (except due to standard processing such as the
LOCAL_OPTIONS option). This also applies to functions marked for autoload within the sticky
emulation; the appropriate set of options will be applied at the point the function is loaded as
well as when it is run.
For example:
emulate sh -c 'fni() { setopt cshnullglob; }
fno() { fni; }'
fno
The two functions fni and fno are defined with sticky sh emulation. fno is then executed, causing
options associated with emulations to be set to their values in sh. fno then calls fni; because
fni is also marked for sticky sh emulation, no option changes take place on entry to or exit from
it. Hence the option cshnullglob, turned off by sh emulation, will be turned on within fni and
remain on return to fno. On exit from fno, the emulation mode and all options will be restored to
the state they were in before entry to the temporary emulation.
The documentation above is typically sufficient for the intended purpose of executing code
designed for other shells in a suitable environment. More detailed rules follow.
1. The sticky emulation environment provided by `emulate shell -c' is identical to that
provided by entry to a function marked for sticky emulation as a consequence of being
defined in such an environment. Hence, for example, the sticky emulation is inherited by
subfunctions defined within functions with sticky emulation.
2. No change of options takes place on entry to or exit from functions that are not marked for
sticky emulation, other than those that would normally take place, even if those functions
are called within sticky emulation.
3. No special handling is provided for functions marked for autoload nor for functions present
in wordcode created by the zcompile command.
4. The presence or absence of the -R switch to emulate corresponds to different sticky
emulation modes, so for example `emulate sh -c', `emulate -R sh -c' and `emulate csh -c'
are treated as three distinct sticky emulations.
5. Difference in shell options supplied in addition to the basic emulation also mean the
sticky emulations are different, so for example `emulate zsh -c' and `emulate zsh -o cbases
-c' are treated as distinct sticky emulations.
enable [ -afmprs ] name ...
Enable the named hash table elements, presumably disabled earlier with disable. The default is to
enable builtin commands. The -a option causes enable to act on regular or global aliases. The -s
option causes enable to act on suffix aliases. The -f option causes enable to act on shell
functions. The -r option causes enable to act on reserved words. Without arguments all enabled
hash table elements from the corresponding hash table are printed. With the -m flag the arguments
are taken as patterns (should be quoted) and all hash table elements from the corresponding hash
table matching these patterns are enabled. Enabled objects can be disabled with the disable
builtin command.
enable -p reenables patterns disabled with disable -p. Note that it does not override globbing
options; for example, `enable -p "~"' does not cause the pattern character ~ to be active unless
the EXTENDED_GLOB option is also set. To enable all possible patterns (so that they may be
individually disabled with disable -p), use `setopt EXTENDED_GLOB KSH_GLOB NO_SH_GLOB'.
eval [ arg ... ]
Read the arguments as input to the shell and execute the resulting command(s) in the current shell
process. The return status is the same as if the commands had been executed directly by the
shell; if there are no args or they contain no commands (i.e. are an empty string or whitespace)
the return status is zero.
exec [ -cl ] [ -a argv0 ] [ command [ arg ... ] ]
Replace the current shell with command rather than forking. If command is a shell builtin command
or a shell function, the shell executes it, and exits when the command is complete.
With -c clear the environment; with -l prepend - to the argv[0] string of the command executed (to
simulate a login shell); with -a argv0 set the argv[0] string of the command executed. See the
section `Precommand Modifiers' in zshmisc(1).
If the option POSIX_BUILTINS is set, command is never interpreted as a shell builtin command or
shell function. This means further precommand modifiers such as builtin and noglob are also not
interpreted within the shell. Hence command is always found by searching the command path.
If command is omitted but any redirections are specified, then the redirections will take effect
in the current shell.
exit [ n ]
Exit the shell with the exit status specified by an arithmetic expression n; if none is specified,
use the exit status from the last command executed. An EOF condition will also cause the shell to
exit, unless the IGNORE_EOF option is set.
See notes at the end of the section JOBS in zshmisc(1) for some possibly unexpected interactions
of the exit command with jobs.
export [ name[=value] ... ]
The specified names are marked for automatic export to the environment of subsequently executed
commands. Equivalent to typeset -gx. If a parameter specified does not already exist, it is
created in the global scope.
false [ arg ... ]
Do nothing and return an exit status of 1.
fc [ -e ename ] [ -s ] [ -LI ] [ -m match ] [ old=new ... ] [ first [ last ] ]
fc -l [ -LI ] [ -nrdfEiD ] [ -t timefmt ] [ -m match ]
[ old=new ... ] [ first [ last ] ]
fc -p [ -a ] [ filename [ histsize [ savehistsize ] ] ]
fc -P
fc -ARWI [ filename ]
The fc command controls the interactive history mechanism. Note that reading and writing of
history options is only performed if the shell is interactive. Usually this is detected
automatically, but it can be forced by setting the interactive option when starting the shell.
The first two forms of this command select a range of events from first to last from the history
list. The arguments first and last may be specified as a number or as a string. A negative
number is used as an offset to the current history event number. A string specifies the most
recent event beginning with the given string. All substitutions old=new, if any, are then
performed on the text of the events.
The range of events selected by numbers can be narrowed further by the following flags.
-I restricts to only internal events (not from $HISTFILE)
-L restricts to only local events (not from other shells, see SHARE_HISTORY in zshoptions(1)
-- note that $HISTFILE is considered local when read at startup)
-m takes the first argument as a pattern (which should be quoted) and only the history events
matching this pattern are considered
If first is not specified, it will be set to -1 (the most recent event), or to -16 if the -l flag
is given. If last is not specified, it will be set to first, or to -1 if the -l flag is given.
However, if the current event has added entries to the history with `print -s' or `fc -R', then
the default last for -l includes all new history entries since the current event began.
When the -l flag is given, the resulting events are listed on standard output. Otherwise the
editor program specified by -e ename is invoked on a file containing these history events. If -e
is not given, the value of the parameter FCEDIT is used; if that is not set the value of the
parameter EDITOR is used; if that is not set a builtin default, usually `vi' is used. If ename is
`-', no editor is invoked. When editing is complete, the edited command is executed.
The flag `-s' is equivalent to `-e -'. The flag -r reverses the order of the events and the flag
-n suppresses event numbers when listing.
Also when listing,
-d prints timestamps for each event
-f prints full time-date stamps in the US `MM/DD/YY hh:mm' format
-E prints full time-date stamps in the European `dd.mm.yyyy hh:mm' format
-i prints full time-date stamps in ISO8601 `yyyy-mm-dd hh:mm' format
-t fmt prints time and date stamps in the given format; fmt is formatted with the strftime
function with the zsh extensions described for the %D{string} prompt format in the section
EXPANSION OF PROMPT SEQUENCES in zshmisc(1). The resulting formatted string must be no
more than 256 characters or will not be printed
-D prints elapsed times; may be combined with one of the options above
`fc -p' pushes the current history list onto a stack and switches to a new history list. If the
-a option is also specified, this history list will be automatically popped when the current
function scope is exited, which is a much better solution than creating a trap function to call
`fc -P' manually. If no arguments are specified, the history list is left empty, $HISTFILE is
unset, and $HISTSIZE & $SAVEHIST are set to their default values. If one argument is given,
$HISTFILE is set to that filename, $HISTSIZE & $SAVEHIST are left unchanged, and the history file
is read in (if it exists) to initialize the new list. If a second argument is specified,
$HISTSIZE & $SAVEHIST are instead set to the single specified numeric value. Finally, if a third
argument is specified, $SAVEHIST is set to a separate value from $HISTSIZE. You are free to
change these environment values for the new history list however you desire in order to manipulate
the new history list.
`fc -P' pops the history list back to an older list saved by `fc -p'. The current list is saved
to its $HISTFILE before it is destroyed (assuming that $HISTFILE and $SAVEHIST are set
appropriately, of course). The values of $HISTFILE, $HISTSIZE, and $SAVEHIST are restored to the
values they had when `fc -p' was called. Note that this restoration can conflict with making
these variables "local", so your best bet is to avoid local declarations for these variables in
functions that use `fc -p'. The one other guaranteed-safe combination is declaring these
variables to be local at the top of your function and using the automatic option (-a) with `fc
-p'. Finally, note that it is legal to manually pop a push marked for automatic popping if you
need to do so before the function exits.
`fc -R' reads the history from the given file, `fc -W' writes the history out to the given file,
and `fc -A' appends the history out to the given file. If no filename is specified, the $HISTFILE
is assumed. If the -I option is added to -R, only those events that are not already contained
within the internal history list are added. If the -I option is added to -A or -W, only those
events that are new since last incremental append/write to the history file are appended/written.
In any case, the created file will have no more than $SAVEHIST entries.
fg [ job ... ]
job ...
Bring each specified job in turn to the foreground. If no job is specified, resume the current
job.
float [ {+|-}Hghlprtux ] [ {+|-}EFLRZ [ n ] ] [ name[=value] ... ]
Equivalent to typeset -E, except that options irrelevant to floating point numbers are not
permitted.
functions [ {+|-}UkmtTuWz ] [ -x num ] [ name ... ]
functions -c oldfn newfn
functions -M [-s] mathfn [ min [ max [ shellfn ] ] ]
functions -M [ -m pattern ... ]
functions +M [ -m ] mathfn ...
Equivalent to typeset -f, with the exception of the -c, -x, -M and -W options. For functions -u
and functions -U, see autoload, which provides additional options. For functions -t and functions
-T, see typeset -f.
The -x option indicates that any functions output will have each leading tab for indentation,
added by the shell to show syntactic structure, expanded to the given number num of spaces. num
can also be 0 to suppress all indentation.
The -W option turns on the option WARN_NESTED_VAR for the named function or functions only. The
option is turned off at the start of nested functions (apart from anonoymous functions) unless the
called function also has the -W attribute.
The -c option causes oldfn to be copied to newfn. The copy is efficiently handled internally by
reference counting. If oldfn was marked for autoload it is first loaded and if this fails the
copy fails. Either function may subsequently be redefined without affecting the other. A typical
idiom is that oldfn is the name of a library shell function which is then redefined to call newfn,
thereby installing a modified version of the function.
The -M and +M flags
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 at most max args. max may
be -1 to indicate that there is no upper limit.
By default the function is implemented by a shell function of the same name; if shellfn is
specified it gives the name of the corresponding shell function while mathfn remains the name used
in arithmetical expressions. The name of the function in $0 is mathfn (not shellfn as would
usually be the case), provided the option FUNCTION_ARGZERO is in effect. The positional
parameters in the shell function correspond to the arguments of the mathematical function call.
The result of the last arithmetical expression evaluated inside the shell function gives the
result of the mathematical function. This is not limited to arithmetic substitutions of the form
$((...)), but also includes arithmetical expressions evaluated in any other way, including by the
let builtin, by ((...)) statements, and even by the return builtin and by array subscripts.
Therefore, care must be taken not to use syntactical constructs that perform arithmetic evaluation
after evaluating what is to be the result of the function. For example:
# WRONG
zmath_cube() {
(( $1 * $1 * $1 ))
return 0
}
functions -M cube 1 1 zmath_cube
print $(( cube(3) ))
This will print `0' because of the return.
Commenting the return out would lead to a different problem: the ((...)) statement would become
the last statement in the function, so the return status ($?) of the function would be non-zero
(indicating failure) whenever the arithmetic result of the function would happen to be zero
(numerically):
# WRONG
zmath_cube() {
(( $1 * $1 * $1 ))
}
functions -M cube 1 1 zmath_cube
print $(( cube(0) ))
Instead, the true builtin can be used:
# RIGHT
zmath_cube() {
(( $1 * $1 * $1 ))
true
}
functions -M cube 1 1 zmath_cube
print $(( cube(3) ))
If the additional option -s is given to functions -M, the argument to the function is a single
string: anything between the opening and matching closing parenthesis is passed to the function as
a single argument, even if it includes commas or white space. The minimum and maximum argument
specifiers must therefore be 1 if given. An empty argument list is passed as a zero-length
string. Thus, the following string function takes a single argument, including the commas, and
prints 11:
stringfn() { (( $#1 )); true }
functions -Ms stringfn
print $(( stringfn(foo,bar,rod) ))
functions -M with no arguments lists all such user-defined functions in the same form as a
definition. With the additional option -m and a list of arguments, all functions whose mathfn
matches one of the pattern arguments are listed.
function +M removes the list of mathematical functions; with the additional option -m the
arguments are treated as patterns and all functions whose mathfn matches the pattern are removed.
Note that the shell function implementing the behaviour is not removed (regardless of whether its
name coincides with mathfn).
getcap See 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 requires 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 set to 1 upon entry to a shell function and restored upon
exit. (The POSIX_BUILTINS option disables this, and also changes the way the value is calculated
to match other shells.) OPTARG is not reset and retains its value from the most recent call to
getopts. If either of OPTIND or OPTARG is explicitly unset, it remains unset, and the index or
option argument is not stored. The option itself is still stored in name in this case.
A leading `:' in optstring causes getopts to store the letter of any invalid option in OPTARG, and
to set name to `?' for an unknown option and to `:' when a required argument is missing.
Otherwise, getopts sets name to `?' and prints an error message when an option is invalid. The
exit status is nonzero when there are no more options.
hash [ -Ldfmrv ] [ name[=value] ] ...
hash can be used to directly modify the contents of the command hash table, and the named
directory hash table. Normally one would modify these tables by modifying one's PATH (for the
command hash table) or by creating appropriate shell parameters (for the named directory hash
table). The choice of hash table to work on is determined by the -d option; without the option
the command hash table is used, and with the option the named directory hash table is used.
A command name starting with a / is never hashed, whether by explicit use of the hash command or
otherwise. Such a command is always found by direct look up in the file system.
Given no arguments, and neither the -r or -f options, the selected hash table will be listed in
full.
The -r option causes the selected hash table to be emptied. It will be subsequently rebuilt in
the normal fashion. The -f option causes the selected hash table to be fully rebuilt immediately.
For the command hash table this hashes all the absolute directories in the PATH, and for the named
directory hash table this adds all users' home directories. These two options cannot be used with
any arguments.
The -m option causes the arguments to be taken as patterns (which should be quoted) and the
elements of the hash table matching those patterns are printed. This is the only way to display a
limited selection of hash table elements.
For each name with a corresponding value, put `name' in the selected hash table, associating it
with the pathname `value'. In the command hash table, this means that whenever `name' is used as
a command argument, the shell will try to execute the file given by `value'. In the named
directory hash table, this means that `value' may be referred to as `~name'.
For each name with no corresponding value, attempt to add name to the hash table, checking what
the appropriate value is in the normal manner for that hash table. If an appropriate value can't
be found, then the hash table will be unchanged.
The -v option causes hash table entries to be listed as they are added by explicit specification.
If has no effect if used with -f.
If the -L flag is present, then each hash table entry is printed in the form of a call to hash.
history
Same as fc -l.
integer [ {+|-}Hghlprtux ] [ {+|-}LRZi [ n ] ] [ name[=value] ... ]
Equivalent to typeset -i, except that options irrelevant to integers are not permitted.
jobs [ -dlprs ] [ job ... ]
jobs -Z string
Lists information about each given job, or all jobs if job is omitted. The -l flag lists process
IDs, and the -p flag lists process groups. If the -r flag is specified only running jobs will be
listed and if the -s flag is given only stopped jobs are shown. If the -d flag is given, the
directory from which the job was started (which may not be the current directory of the job) will
also be shown.
The -Z option replaces the shell's argument and environment space with the given string, truncated
if necessary to fit. This will normally be visible in ps (ps(1)) listings. This feature is
typically used by daemons, to indicate their state.
Full job control is only available in the top-level interactive shell, not in commands run in the
left hand side of pipelines or within the (...) construct. However, a snapshot of the job state
at that point is taken, so it is still possible to use the jobs builtin, or any parameter
providing job information. This gives information about the state of jobs at the point the
subshell was created. If background processes are created within the subshell, then instead
information about those processes is provided.
For example,
sleep 10 & # Job in background
( # Shell forks
jobs # Shows information about "sleep 10 &"
sleep 5 & # Process in background (no job control)
jobs # Shows information about "sleep 5 &"
)
kill [ -s signal_name | -n signal_number | -sig ] 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 current shell is
set to the previously set resource limits of the children.
If limit is not specified, print the current limit placed on resource, otherwise set the limit to
the specified value. If the -h flag is given, use hard limits instead of soft limits. If no
resource is given, print all limits.
When looping over multiple resources, the shell will abort immediately if it detects a badly
formed argument. However, if it fails to set a limit for some other reason it will continue
trying to set the remaining limits.
resource can be one of:
addressspace
Maximum amount of address space used.
aiomemorylocked
Maximum amount of memory locked in RAM for AIO operations.
aiooperations
Maximum number of AIO operations.
cachedthreads
Maximum number of cached threads.
coredumpsize
Maximum size of a core dump.
cputime
Maximum CPU seconds per process.
datasize
Maximum data size (including stack) for each process.
descriptors
Maximum value for a file descriptor.
filesize
Largest single file allowed.
kqueues
Maximum number of kqueues allocated.
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.
posixlocks
Maximum number of POSIX locks per user.
pseudoterminals
Maximum number of pseudo-terminals.
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.
swapsize
Maximum amount of swap used.
vmemorysize
Maximum amount of virtual memory.
Which of these resource limits are available depends on the system. resource can be abbreviated
to any unambiguous prefix. It can also be an integer, which corresponds to the integer defined
for the resource by the operating system.
If argument corresponds to a number which is out of the range of the resources configured into the
shell, the shell will try to read or write the limit anyway, and will report an error if this
fails. As the shell does not store such resources internally, an attempt to set the limit will
fail unless the -s option is present.
limit is a number, with an optional scaling factor, as follows:
nh hours
nk kilobytes (default)
nm megabytes or minutes
ng gigabytes
[mm:]ss
minutes and seconds
The limit command is not made available by default when the shell starts in a mode emulating
another shell. It can be made available with the command `zmodload -F zsh/rlimits b:limit'.
local [ {+|-}AHUahlprtux ] [ {+|-}EFLRZi [ n ] ] [ name[=value] ... ]
Same as typeset, except that the options -g, and -f are not permitted. In this case the -x option
does not force the use of -g, i.e. exported variables will be local to functions.
logout [ n ]
Same as exit, except that it only works in a login shell.
noglob simple command
See the section `Precommand Modifiers' in zshmisc(1).
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
$chpwd_functions are not called, and the new directory stack is not printed. This is useful for
calls to popd that do not change the environment seen by an interactive user.
print [ -abcDilmnNoOpPrsSz ] [ -u n ] [ -f format ] [ -C cols ]
[ -v name ] [ -xX tabstop ] [ -R [ -en ]] [ arg ... ]
With the `-f' option the arguments are printed as described by printf. With no flags or with the
flag `-', the arguments are printed on the standard output as described by echo, with the
following differences: the escape sequence `\M-x' (or `\Mx') metafies the character x (sets the
highest bit), `\C-x' (or `\Cx') produces a control character (`\C-@' and `\C-?' give the
characters NULL and delete), a character code in octal is represented by `\NNN' (instead of
`\0NNN'), and `\E' is a synonym for `\e'. Finally, if not in an escape sequence, `\' escapes the
following character and is not printed.
-a Print arguments with the column incrementing first. Only useful with the -c and -C
options.
-b Recognize all the escape sequences defined for the bindkey command, see the section `Zle
Builtins' in zshzle(1).
-c Print the arguments in columns. Unless -a is also given, arguments are printed with the
row incrementing first.
-C cols
Print the arguments in cols columns. Unless -a is also given, arguments are printed with
the row incrementing first.
-D Treat the arguments as paths, replacing directory prefixes with ~ expressions corresponding
to directory names, as appropriate.
-i If given together with -o or -O, sorting is performed case-independently.
-l Print the arguments separated by newlines instead of spaces. Note: if the list of
arguments is empty, print -l will still output one empty line. To print a possibly-empty
list of arguments one per line, use print -C1, as in `print -rC1 -- "$list[@]"'.
-m Take the first argument as a pattern (should be quoted), and remove it from the argument
list together with subsequent arguments that do not match this pattern.
-n Do not add a newline to the output.
-N Print the arguments separated and terminated by nulls. Again, print -rNC1 -- "$list[@]" is
a canonical way to print an arbitrary list as null-delimited records.
-o Print the arguments sorted in ascending order.
-O Print the arguments sorted in descending order.
-p Print the arguments to the input of the coprocess.
-P Perform prompt expansion (see EXPANSION OF PROMPT SEQUENCES in zshmisc(1)). In combination
with `-f', prompt escape sequences are parsed only within interpolated arguments, not
within the format string.
-r Ignore the escape conventions of echo.
-R Emulate the BSD echo command, which does not process escape sequences unless the -e flag is
given. The -n flag suppresses the trailing newline. Only the -e and -n flags are
recognized after -R; all other arguments and options are printed.
-s Place the results in the history list instead of on the standard output. Each argument to
the print command is treated as a single word in the history, regardless of its content.
-S Place the results in the history list instead of on the standard output. In this case only
a single argument is allowed; it will be split into words as if it were a full shell
command line. The effect is similar to reading the line from a history file with the
HIST_LEX_WORDS option active.
-u n Print the arguments to file descriptor n.
-v name
Store the printed arguments as the value of the parameter name.
-x tab-stop
Expand leading tabs on each line of output in the printed string assuming a tab stop every
tab-stop characters. This is appropriate for formatting code that may be indented with
tabs. Note that leading tabs of any argument to print, not just the first, are expanded,
even if print is using spaces to separate arguments (the column count is maintained across
arguments but may be incorrect on output owing to previous unexpanded tabs).
The start of the output of each print command is assumed to be aligned with a tab stop.
Widths of multibyte characters are handled if the option MULTIBYTE is in effect. This
option is ignored if other formatting options are in effect, namely column alignment or
printf style, or if output is to a special location such as shell history or the command
line editor.
-X tab-stop
This is similar to -x, except that all tabs in the printed string are expanded. This is
appropriate if tabs in the arguments are being used to produce a table format.
-z Push the arguments onto the editing buffer stack, separated by spaces.
If any of `-m', `-o' or `-O' are used in combination with `-f' and there are no arguments (after
the removal process in the case of `-m') then nothing is printed.
printf [ -v name ] format [ arg ... ]
Print the arguments according to the format specification. Formatting rules are the same as used
in C. The same escape sequences as for echo are recognised in the format. All C conversion
specifications ending in one of csdiouxXeEfgGn are handled. In addition to this, `%b' can be used
instead of `%s' to cause escape sequences in the argument to be recognised and `%q' can be used to
quote the argument in such a way that allows it to be reused as shell input. With the numeric
format specifiers, if the corresponding argument starts with a quote character, the numeric value
of the following character is used as the number to print; otherwise the argument is evaluated as
an arithmetic expression. See the section `Arithmetic Evaluation' in zshmisc(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
recommended that you do not mix references of this explicit style with the normal style and the
handling of such mixed styles may be subject to future change.
If arguments remain unused after formatting, the format string is reused until all arguments have
been consumed. With the print builtin, this can be suppressed by using the -r option. If more
arguments are required by the format than have been specified, the behaviour is as if zero or an
empty string had been specified as the argument.
The -v option causes the output to be stored as the value of the parameter name, instead of
printed. If name is an array and the format string is reused when consuming arguments then one
array element will be used for each use of the format string.
pushd [ -qsLP ] [ arg ]
pushd [ -qsLP ] old new
pushd [ -qsLP ] {+|-}n
Change the current directory, and push the old current directory onto the directory stack. In the
first form, change the current directory to arg. If arg is not specified, change to the second
directory on the stack (that is, exchange the top two entries), or change to $HOME if the
PUSHD_TO_HOME option is set or if there is only one entry on the stack. Otherwise, arg is
interpreted as it would be by cd. The meaning of old and new in the second form is also the same
as for cd.
The third form of pushd changes directory by rotating the directory list. An argument of the form
`+n' identifies a stack entry by counting from the left of the list shown by the dirs command,
starting with zero. An argument of the form `-n' counts from the right. If the PUSHD_MINUS
option is set, the meanings of `+' and `-' in this context are swapped.
If the -q (quiet) option is specified, the hook function chpwd and the functions in the array
$chpwd_functions are not called, and the new directory stack is not printed. This is useful for
calls to pushd that do not change the environment seen by an interactive user.
If the option -q is not specified and the shell option PUSHD_SILENT is not set, the directory
stack will be printed after a pushd is performed.
The options -s, -L and -P have the same meanings as for the cd builtin.
pushln [ arg ... ]
Equivalent to print -nz.
pwd [ -rLP ]
Print the absolute pathname of the current working directory. If the -r or the -P flag is
specified, or the CHASE_LINKS option is set and the -L flag is not given, the printed path will
not contain symbolic links.
r Same as fc -e -.
read [ -rszpqAclneE ] [ -t [ num ] ] [ -k [ num ] ] [ -d delim ]
[ -u n ] [ [name][?prompt] ] [ name ... ]
Read one line and break it into fields using the characters in $IFS as separators, except as noted
below. The first field is assigned to the first name, the second field to the second name, etc.,
with leftover fields assigned to the last name. If name is omitted then REPLY is used for scalars
and reply for arrays.
-r Raw mode: a `\' at the end of a line does not signify line continuation and backslashes in
the line don't quote the following character and are not removed.
-s Don't echo back characters if reading from the terminal.
-q Read only one character from the terminal and set name to `y' if this character was `y' or
`Y' and to `n' otherwise. With this flag set the return status is zero only if the
character was `y' or `Y'. This option may be used with a timeout (see -t); if the read
times out, or encounters end of file, status 2 is returned. Input is read from the
terminal unless one of -u or -p is present. This option may also be used within zle
widgets.
-k [ num ]
Read only one (or num) characters. All are assigned to the first name, without word
splitting. This flag is ignored when -q is present. Input is read from the terminal
unless one of -u or -p is present. This option may also be used within zle widgets.
Note that despite the mnemonic `key' this option does read full characters, which may
consist of multiple bytes if the option MULTIBYTE is set.
-z Read one entry from the editor buffer stack and assign it to the first name, without word
splitting. Text is pushed onto the stack with `print -z' or with push-line from the line
editor (see zshzle(1)). This flag is ignored when the -k or -q flags are present.
-e
-E The input read is printed (echoed) to the standard output. If the -e flag is used, no
input is assigned to the parameters.
-A The first name is taken as the name of an array and all words are assigned to it.
-c
-l These flags are allowed only if called inside a function used for completion (specified
with the -K flag to compctl). If the -c flag is given, the words of the current command
are read. If the -l flag is given, the whole line is assigned as a scalar. If both flags
are present, -l is used and -c is ignored.
-n Together with -c, the number of the word the cursor is on is read. With -l, the index of
the character the cursor is on is read. Note that the command name is word number 1, not
word 0, and that when the cursor is at the end of the line, its character index is the
length of the line plus one.
-u n Input is read from file descriptor n.
-p Input is read from the coprocess.
-d delim
Input is terminated by the first character of delim instead of by newline.
-t [ num ]
Test if input is available before attempting to read. If num is present, it must begin
with a digit and will be evaluated to give a number of seconds, which may be a floating
point number; in this case the read times out if input is not available within this time.
If num is not present, it is taken to be zero, so that read returns immediately if no input
is available. If no input is available, return status 1 and do not set any variables.
This option is not available when reading from the editor buffer with -z, when called from
within completion with -c or -l, with -q which clears the input queue before reading, or
within zle where other mechanisms should be used to test for input.
Note that read does not attempt to alter the input processing mode. The default mode is
canonical input, in which an entire line is read at a time, so usually `read -t' will not
read anything until an entire line has been typed. However, when reading from the terminal
with -k input is processed one key at a time; in this case, only availability of the first
character is tested, so that e.g. `read -t -k 2' can still block on the second character.
Use two instances of `read -t -k' if this is not what is wanted.
If the first argument contains a `?', the remainder of this word is used as a prompt on standard
error when the shell is interactive.
The value (exit status) of read is 1 when an end-of-file is encountered, or when -c or -l is
present and the command is not called from a compctl function, or as described for -q. Otherwise
the value is 0.
The behavior of some combinations of the -k, -p, -q, -u and -z flags is undefined. Presently -q
cancels all the others, -p cancels -u, -k cancels -z, and otherwise -z cancels both -p and -u.
The -c or -l flags cancel any and all of -kpquz.
readonly
Same as typeset -r. With the POSIX_BUILTINS option set, same as typeset -gr.
rehash Same as hash -r.
return [ n ]
Causes a shell function or `.' script to return to the invoking script with the return status
specified by an arithmetic expression n. For example, the following prints `42':
() { integer foo=40; return "foo + 2" }
echo $?
If n is omitted, the return status is that of the last command executed.
If return was executed from a trap in a 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 processing; with a non-zero status, the shell
will behave as interrupted except that the return status of the trap is retained. Note that the
numeric value of the signal which caused the trap is passed as the first argument, so the
statement `return "128+$1"' will return the same status as if the signal had not been trapped.
sched See 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 parameters, or declare and set an array.
If the -s option is given, it causes the specified arguments to be sorted before assigning them to
the positional parameters (or to the array name if -A is used). With +s sort arguments in
descending order. For the meaning of the other flags, see zshoptions(1). Flags may be specified
by name using the -o option. If no option name is supplied with -o, the current option states are
printed: see the description of setopt below for more information on the format. With +o they
are printed in a form that can be used as input to the shell.
If the -A flag is specified, name is set to an array containing the given args; if no name is
specified, all arrays are printed together with their values.
If +A is used and name is an array, the given arguments will replace the initial elements of that
array; if no name is specified, all arrays are printed without their values.
The behaviour of arguments after -A name or +A name depends on whether the option KSH_ARRAYS is
set. If it is not set, all arguments following name are treated as values for the array,
regardless of their form. If the option is set, normal option processing continues at that point;
only regular arguments are treated as values for the array. This means that
set -A array -x -- foo
sets array to `-x -- foo' if KSH_ARRAYS is not set, but sets the array to foo and turns on the
option `-x' if it is set.
If the -A flag is not present, but there are arguments beyond the options, the positional
parameters are set. If the option list (if any) is terminated by `--', and there are no further
arguments, the positional parameters will be unset.
If no arguments and no `--' are given, then the names and values of all parameters are printed on
the standard output. If the only argument is `+', the names of all parameters are printed.
For historical reasons, `set -' is treated as `set +xv' and `set - args' as `set +xv -- args' when
in any other emulation mode than zsh's native mode.
setcap See the section `The zsh/cap Module' in zshmodules(1).
setopt [ {+|-}options | {+|-}o option_name ] [ -m ] [ name ... ]
Set the options for the shell. All options specified either with flags or by name are set.
If no arguments are supplied, the names of all options currently set are printed. The form is
chosen so as to minimize the differences from the default options for the current emulation (the
default emulation being native zsh, shown as <Z> in zshoptions(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 expansion), and all options with names matching these patterns are set.
Note that a bad option name does not cause execution of subsequent shell code to be aborted; this
is behaviour is different from that of `set -o'. This is because set is regarded as a special
builtin by the POSIX standard, but setopt is not.
shift [ -p ] [ n ] [ name ... ]
The positional parameters ${n+1} ... are renamed to $1 ..., where n is an arithmetic expression
that defaults to 1. If any names are given then the arrays with these names are shifted instead
of the positional parameters.
If the option -p is given arguments are instead removed (popped) from the end rather than the
start of the array.
source file [ arg ... ]
Same as `.', except that the current directory is always searched and is always searched first,
before directories in $path.
stat See 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 commands are not handled syntactically,
so for example an empty variable expansion may cause an argument to be omitted; syntax errors
cause status 2 to be returned instead of a shell error; and arithmetic operators expect integer
arguments rather than arithmetic expressions.
The command attempts to implement POSIX and its extensions where these are specified.
Unfortunately there are intrinsic ambiguities in the syntax; in particular there is no distinction
between test operators and strings that resemble them. The standard attempts to resolve these for
small numbers of arguments (up to four); for five or more arguments compatibility cannot be relied
on. Users are urged wherever possible to use the `[[' test syntax which does not have these
ambiguities.
times Print the accumulated user and system times for the shell and for processes run from the shell.
trap [ arg ] [ sig ... ]
arg is a series of commands (usually quoted to protect it from immediate evaluation by the shell)
to be read and executed when the shell receives any of the signals specified by one or more sig
args. Each sig can be given as a number, or as the name of a signal either with or without the
string SIG in front (e.g. 1, HUP, and SIGHUP are all the same signal).
If arg is `-', then the specified signals are reset to their defaults, or, if no sig args are
present, all traps are reset.
If arg is an empty string, then the specified signals are ignored by the shell (and by the
commands it invokes).
If arg is omitted but one or more sig args are provided (i.e. the first argument is a valid
signal number or name), the effect is the same as if arg had been specified as `-'.
The trap command with no arguments prints a list of commands associated with each signal.
If sig is ZERR then arg will be executed after each command with a nonzero exit status. ERR is an
alias for ZERR on systems that have no SIGERR signal (this is the usual case).
If sig is DEBUG then arg will be executed before each command if the option DEBUG_BEFORE_CMD is
set (as it is by default), else after each command. Here, a `command' is what is described as a
`sublist' in the shell grammar, see 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 parameter is
unset after the trap is executed.
If sig is 0 or EXIT and the trap statement is executed inside the body of a function, then the
command arg is executed after the function completes. The value of $? at the start of execution
is the exit status of the shell or the return status of the function exiting. If sig is 0 or EXIT
and the trap statement is not executed inside the body of a function, then the command arg is
executed when the shell terminates; the trap runs before any zshexit hook functions.
ZERR, DEBUG, and EXIT traps are not executed inside other traps. ZERR and DEBUG traps are kept
within subshells, while other traps are reset.
Note that traps defined with the trap builtin are slightly different from those defined as
`TRAPNAL () { ... }', as the latter have their own function environment (line numbers, local
variables, etc.) while the former use the environment of the command in which they were called.
For example,
trap 'print $LINENO' DEBUG
will print the line number of a command executed after it has run, while
TRAPDEBUG() { print $LINENO; }
will always print the number zero.
Alternative signal names are allowed as described under kill above. Defining a trap under either
name causes any trap under an alternative name to be removed. However, it is recommended that for
consistency users stick exclusively to one name or another.
true [ arg ... ]
Do nothing and return an exit status of 0.
ttyctl [ -fu ]
The -f option freezes the tty (i.e. terminal or terminal emulator), and -u unfreezes it. When the
tty is frozen, no changes made to the tty settings by external programs will be honored by the
shell, except for changes in the size of the screen; the shell will simply reset the settings to
their previous values as soon as each command exits or is suspended. Thus, stty and similar
programs have no effect when the tty is frozen. Freezing the tty does not cause the current state
to be remembered: instead, it causes future changes to the state to be blocked.
Without options it reports whether the terminal is frozen or not.
Note that, regardless of whether the tty is frozen or not, the shell needs to change the settings
when the line editor starts, so unfreezing the tty does not guarantee settings made on the command
line are preserved. Strings of commands run between editing the command line will see a
consistent tty state. See also the shell variable STTY for a means of initialising the tty before
running external commands and/or freezing the tty around a single command.
type [ -wfpamsS ] name ...
Equivalent to whence -v.
typeset [ {+|-}AHUaghlmrtux ] [ {+|-}EFLRZip [ n ] ]
[ + ] [ name[=value] ... ]
typeset -T [ {+|-}Uglrux ] [ {+|-}LRZp [ n ] ]
[ + | SCALAR[=value] array[=(value ...)] [ sep ] ]
typeset -f [ {+|-}TUkmtuz ] [ + ] [ name ... ]
Set or display attributes and values for shell parameters.
Except as noted below for control flags that change the behavior, a parameter is created for each
name that does not already refer to one. When inside a function, a new parameter is created for
every name (even those that already exist), and is unset again when the function completes. See
`Local Parameters' in zshparam(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. If the assignment is omitted
and name does not refer to an existing parameter, a new parameter is initialized to empty string,
zero, or empty array (as appropriate), unless the shell option TYPESET_TO_UNSET is set. When that
option is set, the parameter attributes are recorded but the parameter remains unset.
If the shell option TYPESET_SILENT is not set, for each remaining name that refers to a parameter
that is already set, the name and value of the parameter are printed in the form of an assignment.
Nothing is printed for newly-created parameters, or when any attribute flags listed below are
given along with the name. Using `+' instead of minus to introduce an attribute turns it off.
If no name is present, the names and values of all parameters are printed. In this case the
attribute flags restrict the display to only those parameters that have the specified attributes,
and using `+' rather than `-' to introduce the flag suppresses printing of the values of
parameters when there is no parameter name.
All forms of the command handle scalar assignment. Array assignment is possible if any of the
reserved words declare, export, float, integer, local, readonly or typeset is matched when the
line is parsed (N.B. not when it is executed). In this case the arguments are parsed as
assignments, except that the `+=' syntax and the GLOB_ASSIGN option are not supported, and scalar
values after = are not split further into words, even if expanded (regardless of the setting of
the KSH_TYPESET option; this option is obsolete).
Examples of the differences between command and reserved word parsing:
# Reserved word parsing
typeset svar=$(echo one word) avar=(several words)
The above creates a scalar parameter svar and an array parameter avar as if the assignments had
been
svar="one word"
avar=(several words)
On the other hand:
# Normal builtin interface
builtin typeset svar=$(echo two words)
The builtin keyword causes the above to use the standard builtin interface to typeset in which
argument parsing is performed in the same way as for other commands. This example creates a
scalar svar containing the value two and another scalar parameter words with no value. An array
value in this case would either cause an error or be treated as an obscure set of glob qualifiers.
Arbitrary arguments are allowed if they take the form of assignments after command line expansion;
however, these only perform scalar assignment:
var='svar=val'
typeset $var
The above sets the scalar parameter svar to the value val. Parentheses around the value within
var would not cause array assignment as they will be treated as ordinary characters when $var is
substituted. Any non-trivial expansion in the name part of the assignment causes the argument to
be treated in this fashion:
typeset {var1,var2,var3}=name
The above syntax is valid, and has the expected effect of setting the three parameters to the same
value, but the command line is parsed as a set of three normal command line arguments to typeset
after expansion. Hence it is not possible to assign to multiple arrays by this means.
Note that each interface to any of the commands may be disabled separately. For example, `disable
-r typeset' disables the reserved word interface to typeset, exposing the builtin interface, while
`disable typeset' disables the builtin. Note that disabling the reserved word interface for
typeset may cause problems with the output of `typeset -p', which assumes the reserved word
interface is available in order to restore array and associative array values.
Unlike parameter assignment statements, typeset's exit status on an assignment that involves a
command substitution does not reflect the exit status of the command substitution. Therefore, to
test for an error in a command substitution, separate the declaration of the parameter from its
initialization:
# WRONG
typeset var1=$(exit 1) || echo "Trouble with var1"
# RIGHT
typeset var1 && var1=$(exit 1) || echo "Trouble with var1"
To initialize a parameter param to a command output and mark it readonly, use typeset -r param or
readonly param after the parameter assignment statement.
If no attribute flags are given, and either no name arguments are present or the flag +m is used,
then each parameter name printed is preceded by a list of the attributes of that parameter (array,
association, exported, float, integer, readonly, or undefined for autoloaded parameters not yet
loaded). If +m is used with attribute flags, and all those flags are introduced with +, the
matching parameter names are printed but their values are not.
The following control flags change the behavior of typeset:
+ If `+' appears by itself in a separate word as the last option, then the names of all
parameters (functions with -f) are printed, but the values (function bodies) are not. No
name arguments may appear, and it is an error for any other options to follow `+'. The
effect of `+' is as if all attribute flags which precede it were given with a `+' prefix.
For example, `typeset -U +' is equivalent to `typeset +U' and displays the names of all
arrays having the uniqueness attribute, whereas `typeset -f -U +' displays the names of all
autoloadable functions. If + is the only option, then type information (array, readonly,
etc.) is also printed for each parameter, in the same manner as `typeset +m "*"'.
-g The -g (global) means that any resulting parameter will not be restricted to local scope.
Note that this does not necessarily mean that the parameter will be global, as the flag
will apply to any existing parameter (even if unset) from an enclosing function. This flag
does not affect the parameter after creation, hence it has no effect when listing existing
parameters, nor does the flag +g have any effect except in combination with -m (see below).
-m If the -m flag is given the name arguments are taken as patterns (use quoting to prevent
these from being interpreted as file patterns). With no attribute flags, all parameters
(or functions with the -f flag) with matching names are printed (the shell option
TYPESET_SILENT is not used in this case).
If the +g flag is combined with -m, a new local parameter is created for every matching
parameter that is not already local. Otherwise -m applies all other flags or assignments
to the existing parameters.
Except when assignments are made with name=value, using +m forces the matching parameters
and their attributes to be printed, even inside a function. Note that -m is ignored if no
patterns are given, so `typeset -m' displays attributes but `typeset -a +m' does not.
-p [ n ]
If the -p option is given, parameters and values are printed in the form of a typeset
command with an assignment, regardless of other flags and options. Note that the -H flag
on parameters is respected; no value will be shown for these parameters.
-p may be followed by an optional integer argument. Currently only the value 1 is
supported. In this case arrays and associative arrays are printed with newlines between
indented elements for readability.
-T [ scalar[=value] array[=(value ...)] [ sep ] ]
This flag has a different meaning when used with -f; see below. Otherwise the -T option
requires zero, two, or three arguments to be present. With no arguments, the list of
parameters created in this fashion is shown. With two or three arguments, the first two
are the name of a scalar and of an array parameter (in that order) that will be tied
together in the manner of $PATH and $path. The optional third argument is a
single-character separator which will be used to join the elements of the array to form the
scalar; if absent, a colon is used, as with $PATH. Only the first character of the
separator is significant; any remaining characters are ignored. Multibyte characters are
not yet supported.
Only one of the scalar and array parameters may be assigned an initial value (the
restrictions on assignment forms described above also apply).
Both the scalar and the array may be manipulated as normal. If one is unset, the other
will automatically be unset too. There is no way of untying the variables without
unsetting them, nor of converting the type of one of them with another typeset command; +T
does not work, assigning an array to scalar is an error, and assigning a scalar to array
sets it to be a single-element array.
Note that both `typeset -xT ...' and `export -T ...' work, but only the scalar will be
marked for export. Setting the value using the scalar version causes a split on all
separators (which cannot be quoted). It is possible to apply -T to two previously tied
variables but with a different separator character, in which case the variables remain
joined as before but the separator is changed.
When an existing scalar is tied to a new array, the value of the scalar is preserved but no
attribute other than export will be preserved.
Attribute flags that transform the final value (-L, -R, -Z, -l, -u) are only applied to the
expanded value at the point of a parameter expansion expression using `$'. They are not applied
when a parameter is retrieved internally by the shell for any purpose.
The following attribute flags may be specified:
-A The names refer to associative array parameters; see `Array Parameters' in zshparam(1).
-L [ n ]
Left justify and remove leading blanks from the value when the parameter is expanded. If n
is nonzero, it defines the width of the field. If n is zero, the width is determined by
the width of the value of the first assignment. In the case of numeric parameters, the
length of the complete value assigned to the parameter is used to determine the width, not
the value that would be output.
The width is the count of characters, which may be multibyte characters if the MULTIBYTE
option is in effect. Note that the screen width of the character is not taken into
account; if this is required, use padding with parameter expansion flags ${(ml...)...} as
described in `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 [ n ]
Similar to -L, except that right justification is used; when the parameter is expanded, the
field is left filled with blanks or truncated from the end. May not be combined with the
-Z flag.
-U For arrays (but not for associative arrays), keep only the first occurrence of each
duplicated value. This may also be set for tied parameters (see -T) or colon-separated
special parameters like PATH or FIGNORE, etc. Note the flag takes effect on assignment,
and the type of the variable being assigned to is determinative; for variables with shared
values it is therefore recommended to set the flag for all interfaces, e.g. `typeset -U
PATH path'.
This flag has a different meaning when used with -f; see below.
-Z [ n ]
Specially handled if set along with the -L flag. Otherwise, similar to -R, except that
leading zeros are used for padding instead of blanks if the first non-blank character is a
digit. Numeric parameters are specially handled: they are always eligible for padding with
zeroes, and the zeroes are inserted at an appropriate place in the output.
-a The names refer to array parameters. An array parameter may be created this way, but it
may be assigned to in the typeset statement only if the reserved word form of typeset is
enabled (as it is by default). When displaying, both normal and associative arrays are
shown.
-f The names refer to functions rather than parameters. No assignments can be made, and the
only other valid flags are -t, -T, -k, -u, -U and -z. The flag -t turns on execution
tracing for this function; the flag -T does the same, but turns off tracing for any named
(not anonymous) function called from the present one, unless that function also has the -t
or -T flag. The -u and -U flags cause the function to be marked for autoloading; -U also
causes alias expansion to be suppressed when the function is loaded. See the description
of the `autoload' builtin for details.
Note that the builtin functions provides the same basic capabilities as typeset -f but
gives access to a few extra options; autoload gives further additional options for the case
typeset -fu and typeset -fU.
-h Hide: only useful for special parameters (those marked `<S>' in the table in zshparam(1)),
and for local parameters with the same name as a special parameter, though harmless for
others. A special parameter with this attribute will not retain its special effect when
made local. Thus after `typeset -h PATH', a function containing `typeset PATH' will create
an ordinary local parameter without the usual behaviour of PATH. Alternatively, the local
parameter may itself be given this attribute; hence inside a function `typeset -h PATH'
creates an ordinary local parameter and the special PATH parameter is not altered in any
way. It is also possible to create a local parameter using `typeset +h special', where the
local copy of special will retain its special properties regardless of having the -h
attribute. Global special parameters loaded from shell modules (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 display 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-special parameters.
-i [ n ]
Use an internal integer representation. If n is nonzero it defines the output arithmetic
base, otherwise it is determined by the first assignment. Bases from 2 to 36 inclusive are
allowed.
-E [ n ]
Use an internal double-precision floating point representation. On output the variable
will be converted to scientific notation. If n is nonzero it defines the number of
significant figures to display; the default is ten.
-F [ n ]
Use an internal double-precision floating point representation. On output the variable
will be converted to fixed-point decimal notation. If n is nonzero it defines the number
of digits to display after the decimal point; the default is ten.
-l Convert the result to lower case whenever the parameter is expanded. The value is not
converted when assigned.
-r The given names are marked readonly. Note that if name is a special parameter, the
readonly attribute can be turned on, but cannot then be turned off.
If the POSIX_BUILTINS option is set, the readonly attribute is more restrictive: unset
variables can be marked readonly and cannot then be set; furthermore, the readonly
attribute cannot be removed from any variable.
It is still possible to change other attributes of the variable though, some of which like
-U or -Z would affect the value. More generally, the readonly attribute should not be
relied on as a security mechanism.
Note that in zsh (like in pdksh but unlike most other shells) it is still possible to
create a local variable of the same name as this is considered a different variable (though
this variable, too, can be marked readonly). Special variables that have been made readonly
retain their value and readonly attribute when made local.
-t Tags the named parameters. Tags 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 subsequently executed commands. If the
option GLOBAL_EXPORT is set, this implies the option -g, unless +g is also explicitly
given; in other words the parameter is not made local to the enclosing function. This is
for compatibility with previous versions of zsh.
ulimit [ -HSa ] [ { -bcdfiklmnpqrsTtvwx | -N resource } [ limit ] ... ]
Set or display resource limits of the shell and the processes started by the shell. The value of
limit can be a number in the unit specified below or one of the values `unlimited', which removes
the limit on the resource, or `hard', which uses the current value of the hard limit on the
resource.
By default, only soft limits are manipulated. If the -H flag is given use hard limits instead of
soft limits. If the -S flag is given together with the -H flag set both hard and soft limits.
If no options are used, the file size limit (-f) is assumed.
If limit is omitted the current value of the specified resources are printed. When more than one
resource value is printed, the limit name and unit is printed before each value.
When looping over multiple resources, the shell will abort immediately if it detects a badly
formed argument. However, if it fails to set a limit for some other reason it will continue
trying to set the remaining limits.
Not all the following resources are supported on all systems. Running ulimit -a will show which
are supported.
-a Lists all of the current resource limits.
-b Socket buffer size in bytes (N.B. not kilobytes)
-c 512-byte blocks on the size of core dumps.
-d Kilobytes on the size of the data segment.
-f 512-byte blocks on the size of files written.
-i The number of pending signals.
-k The number of kqueues allocated.
-l Kilobytes on the size of locked-in memory.
-m Kilobytes on the size of physical memory.
-n open file descriptors.
-p The number of pseudo-terminals.
-q Bytes in POSIX message queues.
-r Maximum real time priority. On some systems where this is not available, such as NetBSD,
this has the same effect as -T for compatibility with sh.
-s Kilobytes on the size of the stack.
-T The number of simultaneous threads available to the user.
-t CPU seconds to be used.
-u The number of processes available to the user.
-v Kilobytes on the size of virtual memory. On some systems this refers to the limit called
`address space'.
-w Kilobytes on the size of swapped out memory.
-x The number of locks on files.
A resource may also be specified by integer in the form `-N resource', where resource corresponds
to the integer defined for the resource by the operating system. This may be used to set the
limits for resources known to the shell which do not correspond to option letters. Such limits
will be shown by number in the output of `ulimit -a'.
The number may alternatively be out of the range of limits compiled into the shell. The shell
will try to read or write the limit anyway, and will report an error if this fails.
umask [ -S ] [ mask ]
The umask is set to mask. mask can be either an octal number or a symbolic value as described in
the chmod(1) man page. If mask is omitted, the current value is printed. The -S option causes
the mask to be printed as a symbolic value. Otherwise, the mask is printed as an octal number.
Note that in the symbolic form the permissions you specify are those which are to be allowed (not
denied) to the users specified.
unalias [ -ams ] name ...
Removes aliases. This command works the same as unhash -a, except that the -a option removes all
regular or global aliases, or with -s all suffix aliases: in this case no name arguments may
appear. The options -m (remove by pattern) and -s without -a (remove listed suffix aliases)
behave as for unhash -a. Note that the meaning of -a is different between unalias and unhash.
unfunction
Same as unhash -f.
unhash [ -adfms ] name ...
Remove the element named name from an internal hash table. The default is remove elements from
the command hash table. The -a option causes unhash to remove regular or global aliases; note
when removing a global aliases that the argument must be quoted to prevent it from being expanded
before being passed to the command. The -s option causes unhash to remove suffix aliases. The -f
option causes unhash to remove shell functions. The -d options causes unhash to remove named
directories. If the -m flag is given the arguments are taken as patterns (should be quoted) and
all elements of the corresponding hash table with matching names will be removed.
unlimit [ -hs ] resource ...
The resource limit for each resource is set to the hard limit. If the -h flag is given and the
shell has appropriate privileges, the hard resource limit for each resource is removed. The
resources of the shell process are only changed if the -s flag is given.
The unlimit command is not made available by default when the shell starts in a mode emulating
another shell. It can be made available with the command `zmodload -F zsh/rlimits b:unlimit'.
unset [ -fmv ] name ...
Each named parameter is unset. Local parameters remain local even if unset; they appear unset
within scope, but the previous value will still reappear when the scope ends.
Individual elements of associative array parameters may be unset by using subscript syntax on
name, which should be quoted (or the entire command prefixed with noglob) to protect the subscript
from filename generation.
If the -m flag is specified the arguments are taken as patterns (should be quoted) and all
parameters with matching names are unset. Note that this cannot be used when unsetting
associative array elements, as the subscript will be treated as part of the pattern.
The -v flag specifies that name refers to parameters. This is the default behaviour.
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 patterns), 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. If job
represents an unknown job or process ID, a warning is printed (unless the POSIX_BUILTINS option is
set) and the exit status is 127.
It is possible to wait for recent processes (specified by process ID, not by job) that were
running in the background even if the process has exited. Typically the process ID will be
recorded by capturing the value of the variable $! immediately after the process has been started.
There is a limit on the number of process IDs remembered by the shell; this is given by the value
of the system configuration parameter CHILD_MAX. When this limit is reached, older process IDs
are discarded, least recently started processes first.
Note there is no protection against the process ID wrapping, i.e. if the wait is not executed soon
enough there is a chance the process waited for is the wrong one. A conflict implies both process
IDs have been generated by the shell, as other processes are not recorded, and that the user is
potentially interested in both, so this problem is intrinsic to process IDs.
whence [ -vcwfpamsS ] [ -x num ] name ...
For each name, indicate how it would be interpreted if used as a command name.
If name is not an alias, built-in command, external command, shell function, hashed command, or a
reserved word, the exit status shall be non-zero, and -- if -v, -c, or -w was passed -- a message
will be written to standard output. (This is different from other shells that write that message
to standard error.)
whence is most useful when name is only the last path component of a command, i.e. does not
include a `/'; in particular, pattern matching only succeeds if just the non-directory component
of the command is passed.
-v Produce a more verbose report.
-c Print the results in a csh-like format. This takes precedence over -v.
-w For each name, print `name: word' where word is one of alias, builtin, command, function,
hashed, reserved or none, according as name corresponds to an alias, a built-in command, an
external command, a shell function, a command defined with the hash builtin, a reserved
word, or is not recognised. This takes precedence over -v and -c.
-f Causes the contents of a shell function to be displayed, which would otherwise not happen
unless the -c flag were used.
-p Do a path search for name even if it is an alias, reserved word, shell function or builtin.
-a Do a search for all occurrences of name throughout the command path. Normally only the
first occurrence is printed.
-m The arguments are taken as patterns (pattern characters should be quoted), and the
information is displayed for each command matching one of these patterns.
-s If a pathname contains symlinks, print the symlink-free pathname as well.
-S As -s, but if the pathname had to be resolved by following multiple symlinks, the
intermediate steps are printed, too. The symlink resolved at each step might be anywhere
in the path.
-x num Expand tabs when outputting shell functions using the -c option. This has the same effect
as the -x option to the functions builtin.
where [ -wpmsS ] [ -x num ] name ...
Equivalent to whence -ca.
which [ -wpamsS ] [ -x num ] name ...
Equivalent to whence -c.
zcompile [ -U ] [ -z | -k ] [ -R | -M ] file [ name ... ]
zcompile -ca [ -m ] [ -R | -M ] file [ name ... ]
zcompile -t file [ name ... ]
This builtin command can be used to compile functions or scripts, storing the compiled form in a
file, and to examine files containing the compiled form. This allows faster autoloading of
functions and sourcing of scripts by avoiding parsing of the text when the files are read.
The first form (without the -c, -a or -t options) creates a compiled file. If only the file
argument is given, the output file has the name `file.zwc' and will be placed in the same
directory as the file. The shell will load the compiled file instead of the normal function file
when the function is autoloaded; see the section `Autoloading Functions' in zshmisc(1) for a
description of how autoloaded functions are searched. The extension .zwc stands for `zsh word
code'.
If there is at least one name argument, all the named files are compiled into the output file
given as the first argument. If file does not end in .zwc, this extension is automatically
appended. Files containing multiple compiled functions are called `digest' files, and are
intended to be used as elements of the FPATH/fpath special array.
The second form, with the -c or -a options, writes the compiled definitions for all the named
functions into file. For -c, the names must be functions currently defined in the shell, not
those marked for autoloading. Undefined functions that are marked for autoloading may be written
by using the -a option, in which case the fpath is searched and the contents of the definition
files for those functions, if found, are compiled into file. If both -c and -a are given, names
of both defined functions and functions marked for autoloading may be given. In either case, the
functions in files written with the -c or -a option will be autoloaded as if the KSH_AUTOLOAD
option were unset.
The reason for handling loaded and not-yet-loaded functions with different options is that some
definition files for autoloading define multiple functions, including the function with the same
name as the file, and, at the end, call that function. In such cases the output of `zcompile -c'
does not include the additional functions defined in the file, and any other initialization code
in the file is lost. Using `zcompile -a' captures all this extra information.
If the -m option is combined with -c or -a, the names are used as patterns and all functions whose
names match one of these patterns will be written. If no name is given, the definitions of all
functions currently defined or marked as autoloaded will be written.
Note the second form cannot be used for compiling functions that include redirections as part of
the definition rather than within the body of the function; for example
fn1() { { ... } >~/logfile }
can be compiled but
fn1() { ... } >~/logfile
cannot. It is possible to use the first form of zcompile to compile autoloadable functions that
include the full function definition instead of just the body of the function.
The third form, with the -t option, examines an existing compiled file. Without further
arguments, the names of the original files compiled into it are listed. The first line of output
shows the version of the shell which compiled the file and how the file will be used (i.e. by
reading it directly or by mapping it into memory). With arguments, nothing is output and the
return status is set to zero if definitions for all names were found in the compiled file, and
non-zero if the definition for at least one name was not found.
Other options:
-U Aliases are not expanded when compiling the named files.
-R When the compiled file is read, its contents are copied into the shell's memory, rather
than memory-mapped (see -M). This happens automatically on systems that do not support
memory mapping.
When compiling scripts instead of autoloadable functions, it is often desirable to use this
option; otherwise the whole file, including the code to define functions which have already
been defined, will remain mapped, consequently wasting memory.
-M The compiled file is mapped into the shell's memory when read. This is done in such a way
that multiple instances of the shell running on the same host will share this mapped file.
If neither -R nor -M is given, the zcompile builtin decides what to do based on the size of
the compiled file.
-k
-z These options are used when the compiled file contains functions which are to be
autoloaded. If -z is given, the function will be autoloaded as if the KSH_AUTOLOAD option
is not set, even if it is set at the time the compiled file is read, while if the -k is
given, the function will be loaded as if KSH_AUTOLOAD is set. These options also take
precedence over any -k or -z options specified to the autoload builtin. If neither of these
options is given, the function will be loaded as determined by the setting of the
KSH_AUTOLOAD option at the time the compiled file is read.
These options may also appear as many times as necessary between the listed names to
specify the loading style of all following functions, up to the next -k or -z.
The created file always contains two versions of the compiled format, one for big-endian
machines and one for small-endian machines. The upshot of this is that the compiled file
is machine independent and if it is read or mapped, only one half of the file is actually
used (and mapped).
zformat
See 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 ] [ -s ] [ ... ]
zmodload -F [ -alLme -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 modules are printed. The -L option
causes this list to be in the form of a series of zmodload commands. Forms with arguments are:
zmodload [ -is ] name ...
zmodload -u [ -i ] name ...
In the simplest case, zmodload loads a binary module. The module must be in a file with a
name consisting of the specified name followed by a standard suffix, usually `.so' (`.sl'
on HPUX). If the module to be loaded is already loaded the duplicate module is ignored.
If zmodload detects an inconsistency, such as an invalid module name or circular dependency
list, the current code block is aborted. If it is available, the module is loaded if
necessary, while if it is not available, non-zero status is silently returned. The option
-i is accepted for compatibility but has no effect.
The named module is searched for in the same way a command is, using $module_path instead
of $path. However, the path search is performed even when the module name contains a `/',
which it usually does. There is no way to prevent the path search.
If the module supports features (see below), zmodload tries to enable all features when
loading a module. If the module was successfully loaded but not all features could be
enabled, zmodload returns status 2.
If the option -s is given, no error is printed if the module was not available (though
other errors indicating a problem with the module are printed). The return status
indicates if the module was loaded. This is appropriate if the caller considers the module
optional.
With -u, zmodload unloads modules. The same name must be given that was given when the
module was loaded, but it is not necessary for the module to exist in the file system. The
-i option suppresses the error if the module is already unloaded (or was never loaded).
Each module has a boot and a cleanup function. The module will not be loaded if its boot
function fails. Similarly a module can only be unloaded if its cleanup function runs
successfully.
zmodload -F [ -almLe -P param ] module [ [+-]feature ... ]
zmodload -F allows more selective control over the features provided by modules. With no
options apart from -F, the module named module is loaded, if it was not already loaded, and
the list of features is set to the required state. If no features are specified, the
module is loaded, if it was not already loaded, but the state of features is unchanged.
Each feature may be preceded by a + to turn the feature on, or - to turn it off; the + is
assumed if neither character is present. Any feature not explicitly mentioned is left in
its current state; if the module was not previously loaded this means any such features
will remain disabled. The return status is zero if all features were set, 1 if the module
failed to load, and 2 if some features could not be set (for example, a parameter couldn't
be added because there was a different parameter of the same name) but the module was
loaded.
The standard features are builtins, conditions, parameters and math functions; these are
indicated by the prefix `b:', `c:' (`C:' for an infix condition), `p:' and `f:',
respectively, followed by the name that the corresponding feature would have in the shell.
For example, `b:strftime' indicates a builtin named strftime and p:EPOCHSECONDS indicates a
parameter named EPOCHSECONDS. The module may provide other (`abstract') features of its
own as indicated by its documentation; these have no prefix.
With -l or -L, features provided by the module are listed. With -l alone, a list of
features together with their states is shown, one feature per line. With -L alone, a
zmodload -F command that would cause enabled features of the module to be turned on is
shown. With -lL, a zmodload -F command that would cause all the features to be set to
their current state is shown. If one of these combinations is given with the option -P
param then the parameter param is set to an array of features, either features together
with their state or (if -L alone is given) enabled features.
With the option -L the module name may be omitted; then a list of all enabled features for
all modules providing features is printed in the form of zmodload -F commands. If -l is
also given, the state of both enabled and disabled features is output in that form.
A set of features may be provided together with -l or -L and a module name; in that case
only the state of those features is considered. Each feature may be preceded by + or - but
the character has no effect. If no set of features is provided, all features are
considered.
With -e, the command first tests that the module is loaded; if it is not, status 1 is
returned. If the module is loaded, the list of features given as an argument is examined.
Any feature given with no prefix is simply tested to see if the module provides it; any
feature given with a prefix + or - is tested to see if is provided and in the given state.
If the tests on all features in the list succeed, status 0 is returned, else status 1.
With -m, each entry in the given list of features is taken as a pattern to be matched
against the list of features provided by the module. An initial + or - must be given
explicitly. This may not be combined with the -a option as autoloads must be specified
explicitly.
With -a, the given list of features is marked for autoload from the specified module, which
may not yet be loaded. An optional + may appear before the feature name. If the feature
is prefixed with -, any existing autoload is removed. The options -l and -L may be used to
list autoloads. Autoloading is specific to individual features; when the module is loaded
only the requested feature is enabled. Autoload requests are preserved if the module is
subsequently unloaded until an explicit `zmodload -Fa module -feature' is issued. It is
not an error to request an autoload for a feature of a module that is already loaded.
When the module is loaded each autoload is checked against the features actually provided
by the module; if the feature is not provided the autoload request is deleted. A warning
message is output; if the module is being loaded to provide a different feature, and that
autoload is successful, there is no effect on the status of the current command. If the
module is already loaded at the time when zmodload -Fa is run, an error message is printed
and status 1 returned.
zmodload -Fa can be used with the -l, -L, -e and -P options for listing and testing the
existence of autoloadable features. In this case -l is ignored if -L is specified.
zmodload -FaL with no module name lists autoloads for all modules.
Note that only standard features as described above can be autoloaded; other features
require the module to be loaded before enabling.
zmodload -d [ -L ] [ name ]
zmodload -d name dep ...
zmodload -ud name [ dep ... ]
The -d option can be used to specify module dependencies. The modules named in the second
and subsequent arguments will be loaded before the module named in the first argument.
With -d and one argument, all dependencies for that module are listed. With -d and no
arguments, all module dependencies are listed. This listing is by default in a
Makefile-like format. The -L option changes this format to a list of zmodload -d commands.
If -d and -u are both used, dependencies are removed. If only one argument is given, all
dependencies for that module are removed.
zmodload -ab [ -L ]
zmodload -ab [ -i ] name [ builtin ... ]
zmodload -ub [ -i ] builtin ...
The -ab option defines autoloaded builtins. It defines the specified builtins. When any
of those builtins is called, the module specified in the first argument is loaded and all
its features are enabled (for selective control of features use `zmodload -F -a' as
described above). If only the name is given, one builtin is defined, with the same name as
the module. -i suppresses the error if the builtin is already defined or autoloaded, but
not if another builtin of the same name is already defined.
With -ab and no arguments, all autoloaded builtins are listed, with the module name (if
different) shown in parentheses after the builtin name. The -L option changes this format
to a list of zmodload -a commands.
If -b is used together with the -u option, it removes builtins previously defined with -ab.
This is only possible if the builtin is not yet loaded. -i suppresses the error if the
builtin is already removed (or never existed).
Autoload requests are retained if the module is subsequently unloaded until an explicit
`zmodload -ub builtin' is issued.
zmodload -ac [ -IL ]
zmodload -ac [ -iI ] name [ cond ... ]
zmodload -uc [ -iI ] cond ...
The -ac option is used to define autoloaded condition codes. The cond strings give the
names of the conditions defined by the module. The optional -I option is used to define
infix condition names. Without this option prefix condition names are defined.
If given no condition names, all defined names are listed (as a series of zmodload commands
if the -L option is given).
The -uc option removes definitions for autoloaded conditions.
zmodload -ap [ -L ]
zmodload -ap [ -i ] name [ parameter ... ]
zmodload -up [ -i ] parameter ...
The -p option is like the -b and -c options, but makes zmodload work on autoloaded
parameters instead.
zmodload -af [ -L ]
zmodload -af [ -i ] name [ function ... ]
zmodload -uf [ -i ] function ...
The -f option is like the -b, -p, and -c options, but makes zmodload work on autoloaded
math functions instead.
zmodload -a [ -L ]
zmodload -a [ -i ] name [ builtin ... ]
zmodload -ua [ -i ] builtin ...
Equivalent to -ab and -ub.
zmodload -e [ -A ] [ string ... ]
The -e option without arguments lists all loaded modules; if the -A option is also given,
module aliases corresponding to loaded modules are also shown. If arguments are provided,
nothing is printed; the return status is set to zero if all strings given as arguments are
names of loaded modules and to one if at least on string is not the name of a loaded
module. This can be used to test for the availability of things implemented by modules.
In this case, any aliases are automatically resolved and the -A flag is not used.
zmodload -A [ -L ] [ modalias[=module] ... ]
For each argument, if both modalias and module are given, define modalias to be an alias
for the module module. If the module modalias is ever subsequently requested, either via a
call to zmodload or implicitly, the shell will attempt to load module instead. If module
is not given, show the definition of modalias. If no arguments are given, list all defined
module aliases. When listing, if the -L flag was also given, list the definition as a
zmodload command to recreate the alias.
The existence of aliases for modules is completely independent of whether the name resolved
is actually loaded as a module: while the alias exists, loading and unloading the module
under any alias has exactly the same effect as using the resolved name, and does not affect
the connection between the alias and the resolved name which can be removed either by
zmodload -R or by redefining the alias. Chains of aliases (i.e. where the first resolved
name is itself an alias) are valid so long as these are not circular. As the aliases take
the same format as module names, they may include path separators: in this case, there is
no requirement for any part of the path named to exist as the alias will be resolved first.
For example, `any/old/alias' is always a valid alias.
Dependencies added to aliased modules are actually added to the resolved module; these
remain if the alias is removed. It is valid to create an alias whose name is one of the
standard shell modules and which resolves to a different module. However, if a module has
dependencies, it will not be possible to use the module name as an alias as the module will
already be marked as a loadable module in its own right.
Apart from the above, aliases can be used in the zmodload command anywhere module names are
required. However, aliases will not be shown in lists of loaded modules with a bare
`zmodload'.
zmodload -R modalias ...
For each modalias argument that was previously defined as a module alias via zmodload -A,
delete the alias. If any was not defined, an error is caused and the remainder of the line
is ignored.
Note that zsh makes no distinction between modules that were linked into the shell and modules
that are loaded dynamically. In both cases this builtin command has to be used to make available
the builtins and other things defined by modules (unless the module is autoloaded on these
definitions). This is true even for systems that don't support dynamic loading of modules.
zparseopts
See 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 5.9 May 14, 2022 ZSHBUILTINS(1)