zshbuiltins(1)

NAME

zshbuiltins - zsh built-in functions

DESCRIPTIONS

- simple command

See the secion 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 direc

tory are not read unless "." appears somewhere in path. If any

arguments arg are given, they become the positional parameters;

the old positional parameters are restored when the file is done

executing. The exit status is the exit status of the last com

mand executed.

: [ arg ... ]

This command only expands parameters. A zero exit

code is returned.

alias [ -gmrL ] [ 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 substitution. If the -g flag is

present, define a global alias; global aliases are expanded even

if they do not occur in command position. For each name with no

value, print the value of name, if any. With no arguments, print

all currently defined aliases. If the -m flag is given the argu

ments 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

the -g or -r flags are present, then restrict the printing to

global or regular aliases, respectively. 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.

autoload [ name ... ]

For each of the names (which are names of func

tions), create a function marked undefined. The fpath variable

will be searched to find the actual function definition when the

function is first referenced. The definition is contained in a

file of the same name as the function. If the file found con

tains a standard definition for the function, that is stored as

the function; otherwise, the contents of the entire file are

stored as the function. The latter format allows functions to be

used directly as scripts.

bg [ job ... ]
job ... &

Put each specified job in the background, or the

current job if none is specified.

bindkey -mevd
bindkey -r in-string ...
bindkey [ -a ] in-string [ command ] ... bindkey -s [ -a ] in-string out-string ...

The -e and -v options put the keymaps in emacs mode

or vi mode respectively; they cannot be used simultaneously. The

-d option resets all bindings to the compiled-in settings. If not

used with options -e or -v, the maps will be left in emacs mode,

or in vi mode if the VISUAL or EDITOR variables exist and contain

the string "vi". Metafied characters are bound to self-insert by

default. The -m option loads the compiled-in bindings of these

characters for the mode determined by the preceding options, or

the current mode if used alone. Any previous bindings done by the

user will be preserved. If the -r option is given, remove any

binding for each in-string. If the -s option is not specified,

bind each in-string to a specified command. If no command is

specified, print the binding of in-string if it is bound, or re

turn a nonzero exit code if it is not bound. If the -s option is

specified, bind each in-string to each specified out-string. When

in-string is typed, out-string will be pushed back and treated as

input to the line editor. This process is recursive but, to avoid

infinite loops, the shell will report an error if more than 20

consecutive replacements happen. If the -a option is specified,

bind the in-strings in the alternative keymap instead of the

standard one. The alternative keymap is used in vi command mode.

It's pobsible for an in-string to be bound to some

thing and also be the beginning of a longer bound string. In this

case the shell will wait a certain time to see if more characters

are typed and if not it will execute the binding. This timeout is

defined by the KEYTIMEOUT parameter; its default is 0.4 sec. No

timeout is done if the prefix string is not bound.

b

For eitaer in-string or out-string, control charac

ters may be specified in the form ^X, and the backslash may be

used to introduce one of the following escape sequences:

ac bell character

k linefeed (newline)
s

tp horizontal tab

a vertical tab

rf carriageereturn

e

e,E escape

NN character code in octal
NN character code in hexadecimal
M-xxx character or escape sequence with meta

bit set. The `-' after the `M' is optional.
-X control character. The `-' after the

`C' is optional.

In all other cases, escapes the following charac

ter. Delete is written as `^?'. Note that `?' and `^' are not

the same.

Multi-character in-strings cannot contain the null

character ("^@" or "^ "). If they appear in a bindkey command,

they will be silently translated to "^@". This restriction does

not apply to out-strings, single-character in-strings and the

first character of a multi-char in-string.

break [ n ]

Exit from an enclosing for, while, until, select,

or repeat loop. If n is specified, then break n levels instead

of just one.

builtin name [ args ] ...

Executes the builtin name, with the given args.

bye Same as exit.

cd [ arg ]
cd old new
cd ±n Change the current directory. In the first form,

change the current directory to arg, or to the value of HOME if

arg is not specified. If arg is -, change to the value of

OLDPWD

found in the current directory and arg does not begin with a
slash, search each component of the shell parameter cdpath. If the option CDABLEVARS is set, and a parameter named arg exists whose value begins with a slash, treat its value as the directory.
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 di

rectory 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.

chdir Same as cd.

command simple command

See the secion PRECOMMAND MODIFIERS in zshmisc(1).

compctl

Compctl has it's own man page. Check

zshcompctl(1).

continue [ num ]

Resume the next iteration of the enclosing for,

while, until, select, or repeat loop. If n is specified, break

out of n - 1 loops and resume at the nth enclosing loop.

declare [ arg ... ]

Same as typeset.

dirs [ -v ] [ arg ... ]

With no arguments, print the contents of the direc

tory stack. If the -v option is given, number the directories in

the stack when printing. 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.

disable [ -afmr ] arg ...

Disable the hash table element named arg temporari

ly. The default is to disable builtin commands. This allows you

to use an external command with the same name as a builtin com

mand. The -a option causes disable to act on aliases. The -f

option causes disable to act on shell functions. The -r options

causes disable to act on reserved words. Without arguments all

disabled hash table elements from the corresponding hash table

are printed. With the -m flag the arguments are taken as pat

terns (should be quoted to preserve them from being taken as glob

patterns) and all hash table elements from the corresponding hash

table matching these patterns are disabled. Disabled objects can

be enabled with the enable command.

disown [ job ... ]
job ... &
job ... &!

bRemove 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, use the current job.
b

echo [a-neE ] [ arg ... ]

cWrite each arg on the standard output, with a space

separating each one. If the -n flag is not present, print a new

line at the end. echo recognizes the following escape sequences:

ak bell character

s
p e escape
f form feed

rn carriage return

e

t horizontal tab

vertical tab

backslash

0NNN character code in octal, with a maximum of

three digits after the zero; a non-octal digit terminates the

number
NN character code in hexadecimal, with a maximum

of two digits after the `x'; a non-hexadecimal digit terminates

the number.

The -E falg or the BSD_ECHO option can be used to

disable these escape sequences. In the later case -e flag can be

used to enable them.

echotc cap [ arg ... ]

Output the termcap string corresponding to the ca

pability cap, with optional arguments.

emulate [ -LR ] [ zsh | sh | ksh | csh ]

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. If the -R option is given, all options are reset

to their default value corresponding to the specified emulation

mode, except for certain options describing the interactive envi

ronment; otherwise, only those options likely to cause portabili

ty problems in scripts and functions are altered. If the -L op

tion is given, the option LOCAL_OPTIONS will be set as well,

causing the effect of the emulate command to be local to the im

mediately surrounding shell function, if any; normally this is

turned off in all emulation modes except ksh.

enable [ -afmr ] arg ...

Enable the hash table element named arg, presumably

disabled earlier with disable. The default is to enable builtin

commands. The -a option causes enable to act on aliases. The -f

option causes enable to act on shell functions. The -r option

causes enable to act on reserved words. Without arguments all

enable hash table elememts 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 corre

sponding hash table matching these patterns are enabled. Enabled

objects can be disabled with the disable builtin command.

eval [ arg ... ]

Read the arguments as input to the shell and exe

cute the resulting command(s) in the current shell process.

exec simple command

See the secion PRECOMMAND MODIFIERS in zshmisc(1).

exit [ n ]

Exit the shell with the exit code specified by n;

if none is specified, use the exit code from the last command ex

ecuted. An EOF condition will also cause the shell to exit, un

less the IGNOREEOF option is set.

export [ name[=value] ... ]

The specified names are marked for automatic export

to the environment of subsequently executed commands. export is

equivalent to typeset -x.

false Do nothing and return an exit code of 1.

fc [ -e ename ] [ -nlrdDfEim ] [ old=new ... ] [ first [

last ] ]
fc -ARWI [ filename ]

Select a range of commands from first to last from

the history list. The arguments first and last may be specified

as a number or as a string. A negative number is used as an off

set to the current history event number. A string specifies the

most recent event beginning with the given string. All substitu

tions old=new, if any, are then performed on the commands. If

the -l flag is given, the resulting commands are listed on stan

dard output. If the -m flag is also given the first argument is

taken as a pattern (should be quoted) and only the history events

matching this pattern will be shown. Otherwise the editor pro

gram ename is invoked on a file containing these history events.

If ename is not given, the value of the parameter FCEDIT is used.

If ename is "-", no editor is invoked. When editing is complete,

the edited command(s) is executed. If first is not specified, it

will be set to -1 (the most recent event), or to -16 if the -l

flag is given. If last is not specified, it will be set to

first, or to -1 if the -l flag is given. The flag -r reverses

the order of the commands and the flag -n suppresses command num

bers when listing. Also when listing, -d prints timestamps for

each command, and -f prints full time-date stamps. Adding the -E

flag causes the dates to be printed as `dd.mm.yyyy', instead of

the default `mm/dd/yyyy'. Adding the -i flag causes the dates to

be printed as `yyyy-mm-dd', in a fixed format. With the -D flag,

fc prints elapsed times.

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. fc -AI (-WI) appends (writes) on

ly those events that are new since last incremental append

(write) to the history file. In any case the file will have no

more than SAVEHIST entries.

fg [ job ... ]
job ...

Bring the specified jobs to the foreground. If no

job is specified, use the current job.

functions [ ±tum ] [ name ... ]

Equivalent to typeset -f.

getln name ...

Read the top value from the buffer stack and put it

in the shell parameter name. Equivalent to read -zr. The flags

-c, -l, -A, -e, -E, and -n are supported, too.

getopts optstring name [ arg ... ]

Checks arg for legal options. If arg is 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. optstring contains the let

ters that getopts recognizes. If a letter is followed by a `:',

that option is expected to have an argument. The options can be

separated from the argument by blanks.

Each time it is invoked, getopts places the option

letter it finds in the shell parameter name, prepended with a +

when arg begins with a +. The index of the next arg is stored in

OPTIND

A leading : in optstring causes getopts to store

the letter of the invalid option in OPTARG, and to set name to

`?' for an unknown option and to `:' when a required option is

missing. Otherwise, getopts prints an error message. The exit

status is nonzero when there are no more options.

hash [ -dfmr ] [ name[=value] ] ...

With no arguments or options, hash will list the

entire command hash table.

The -m option causes the arguments to be taken as

patterns (they should be quoted) and the elements of the command

hash table matching these patterns are printed.

The -r option causes the command hash table to be

thrown out and restarted. The -f option causes the entire path

to be searched, and all the commands found are added to the hash

table. These options cannot be used with any arguments.

For each name with a corresponding value, put name

in the command hash table, associating it with the pathname

value. Whenever name is used as a command argument, the shell

will try to execute the file given by value. For each name with

no corresponding value, search for name in the path, and add it

to the command hash table, and associating it with the discovered

path, if it is found.

Adding the -d option causes hash to act on the

named directory table instead of the command hash table. The re

maing discussion of hash will assume that the -d is given.

If invoked without any arguments, and without any

other options, hash -d lists the entire named directory table.

The -m option causes the arguments to be taken as

patterns (they should be quoted) and the elements of the named

directory table matching these patterns are printed.

The -r option causes the named directory table to

be thrown out and restarted so that it only contains `~'. The -f

option causes all usernames to be added to the named directory

table. There options cannot be used with any arguments.

For each name with a corresponding value, put name

in the named directory table. The directory name name is then

associated with the specified path value, so that value may be

referred to as `~name'. For each name with no corresponding

value, search for as a username and as a parameter. If it is

found, it is added to the named directory hash table.

history [ -nrdDfEim ] [ first [ last ] ]

Same as fc -l.

integer [ ±lrtux ] [ name[=value] ] ...

Same as typeset -i, except that options irrelevant

to integers are not permitted.

jobs [ -lprs ] [ job ... ]

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 run

ning jobs will be listed and if the -s flag is given only stopped

jobs are shown.

kill [ -s signal_name ] job ...
kill [ -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, 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 third form, kill -l, if sig is not speci

fied 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.

let arg ...

Evaluate each arg as an arithmetic expression. See

ARITHMETIC EVALUATION

metic expressions. The exit status is 0 if the value of the last
expression is nonzero, and 1 otherwise.
limit [ -hs ] [ resource [ limit ] ] ...

Set or display resource limits. Unless the -s flag

is given the limit applies only the children of the shell. If -s

is given without other arguments, the resource limits of the cur

rent shell is set to the previously set resource limits of the

children. If limit is not specified, print the current limit

placed on resource; otherwise set the limit to the specified val

ue. If the -h flag is given, use hard limits instead of soft

limits. If no resource is given, print all limits.

resource is one of:

cputime

Maximum CPU seconds per process.

filesize

Largest single file allowed.

datasize

Maximum data size (including stack) for each

process.

stacksize

Maximum stack size for each process.

coredumpsize

Maximum size of a core dump.

resident

Maximum resident set size.

memoryuse

The same as resident.

memorylocked

Maximum amount of memory locked in RAM.

descriptors

Maximum value for a file descriptor.

openfiles

Maximum number of open files.

vmemorysize

Maximum amount of virtual memory.

Which of these resource limits are available de

pends on the system. limit is a number, with an optional scaling

factor, as follows:

nh hours.
nk kilobytes. This is the default for all but

cputime.
nm megabytes or minutes.
mm:ss minutes and seconds.

local [ ±LRZilrtu [n]] [ name[=value] ] ...

Same as typeset, except that the options -x and -f

are not permitted.

log List all users currently logged in who are affected

by the current setting of the watch parameter.

logout Exit the shell, if this is a login shell.

noglob simple command

See the secion PRECOMMAND MODIFIERS in zshmisc(1).

popd [ ±n ]

Removes a entry from the directory stack, and per

form 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.

print [ -nrslzpNDPoOicm ] [ -un ] [ -R [ -en ]] [ arg ...

]

With no flags or with flag -, the arguments are

printed on the standard output as described by echo, with the

following differences: the escape sequence x metafies the charac

ter x (sets the highest bit), produces a control character (and

give the characters NULL and delete) and is a synonym for . Fi

nally, if not in an escape sequence, escapes the following char

acter and is not printed.
-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.
-m Take the fist argument as a pattern (should

be quoted) and remove it from the argument list together with

subsequent arguments that do not match this pattern.
-s place the results in the history list in

stead of on the standard output.
-n do not add a newline to the output.
-l print the arguments separated by newlines

instead of spaces.
-N print the arguments separated and terminated

by nulls.
-o print the arguments sorted in ascending or

der.
-O print the arguments sorted in descending or

der.
-i if given together with -o or -O makes them

work case independently
-c print the arguments in columns
-un print the arguments to file descriptor n.
-p print the arguments to the input of the co

process.
-z push the arguments onto the editing buffer

stack, separated by spaces; no escape sequences are recognized.
-D treat the arguments as directory names, re

placing prefixes with ~ expressions, as appropriate.
-P recognize the same escape sequences as in

the PROMPT parameter.

pushd [ arg ]
pushd old new
pushd ±n

Change the current directory, and push the old cur

rent 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 the value of HOME if the

PUSHD_TO_HOME

stack. If arg is -, change to the value of OLDPWD, the previous directory. If a directory named arg is not found in the current
directory and arg does not contain a slash, search each component
of the shell parameter cdpath. If the option CDABLEVARS is set, and a parameter named arg exists whose value begins with a slash,
treat its value as the directory. If the option PUSHD_SILENT is not set, the directory stack will be printed after a pushd is
performed.
The second form of pushd 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 pushd changes directory by rotat

ing 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.

pushln Equivalent to print -nz.

pwd [ -r ]

Print the absolute pathname of the current working

directory. If the -r flag is specified or the CHASE_LINKS option

is set, the printed path will not contain symbolic links.

r Equivalent to fc -e -.

read [ -rzpqAclneE ] [ -k [ num ] ]

[ -un ] [ name?prompt ] [ name ... ]

Read one line and break it into fields using the

characters in IFS as separators.
-r Raw mode: a at the end of a line does not

signify line continuation.
-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 value is zero only if

the character was `y' or `Y'.
-k [ num ]

Read only one (or num) characters from the

terminal.

-z Read from the editor buffer stack. 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.
-e
-E The words read are printed after the whole

line is read. If the -e flag is set, the words are not 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 in

side 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 as

signed as a scalar. If name is omitted then REPLY is used for

scalars and reply for arrays.
-n Together with either of the previous flags,

this option gives the number of the word the cursor is on or the

index of the character the cursor is on respectively.
-un Input is read from file descriptor n.
-p Input is read from the coprocess.

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 exit status is 0 unless an end-of-file is

encountered.

readonly [ name[=value] ] ...

The given names are marked readonly; these names

cannot be changed by subsequent assignment.

rehash [ -df ]

Throw out the command hash table and start over.

If the -f option is set, rescan the command path immediately, in

stead of rebuilding the hash table incrementally.

The -d option causes rehash to act on the named di

rectory table instead of the command hash table. This reduces

the named directory table to only the `~' entry. If the -f op

tion is also used, the named directory table is rebuilt immedi

ately.

rehash is equivalent to hash -r.

return [ n ]

Causes a shell function or . script to return to

the invoking script with the return status specified by n. If n

is omitted then the return status is that of the last command ex

ecuted.

If return was executed from a trap in a TRAPxxx

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 in

terrupted except that the return status of the trap is retained.

Note that 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 [+]hh:mm command ...
sched [ -item ]

Make an entry in the scheduled list of commands to

execute. The time may be specified in either absolute or rela

tive time. With no arguments, prints the list of scheduled com

mands. With the argument -item, removes the given item from the

list.

set [ ±options ] [ ±o option name ] ... [ ±A [ name ] ] [

arg ... ]

Set the options for the shell and/or set the posi

tional 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 the zshoptions man page.

Flags may be specified by name using the -o option. If the -A

flag is specified, name is set to an array containing the given

args; if +A is used and name is an array, the gien arguments will

replace the initial elements of that array; if no name is speci

fied, all arrays are printed. Otherwise the positional parameters

are set. If no arguments 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.

setopt [ ±options ] [ name ... ]

Set the options for the shell. All options speci

fied either with flags or by name are set. If no arguments are

supplied, the names of all options currently set are printed. In

option names, case is insignificant, and all underscore charac

ters are ignored. If the -m flag is given the arguments are tak

en as patterns (should be quoted to preserve them from being in

terpreted as glob patterns) and all options with names matching

these patterns are set.

shift [ n ] [ name ... ]

The positional parameters from $n+1 ... are renamed

$1, where n is an arithmetic expression that defaults to 1. If

any names are given then the arrays with these names are shifted

instead of the positional parameters.

source Same as ., except that the current directory is al

ways searched and is always searched first, before directories in

path.

suspend [ -f ]

Suspend the execution of the shell (send it a

SIGTSTP

given, complain if this is a login shell.
test arg ...
[ arg ... ]

Like the system version of test. Added for compat

ibility; use conditional expressions instead.

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 pro

tect it from immediate evaluation by the shell) to be read and

executed when the shell receives sig. Each sig can be given as a

number or as the name of a signal. If arg is -, then all traps

sig are reset to their default values. If arg is the null

string, then this signal is ignored by the shell and by the com

mands it invokes. If sig is ZERR then arg will be executed after

each command with a nonzero exit status. If sig is DEBUG then

arg will be executed after each command. 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.

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 command with no arguments prints a

list of commands associated with each signal. 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.

true Do nothing and return an exit code of 0.

ttyctl -fu

The -f option freezes the tty, and -u unfreezes it.

When the tty is frozen, no changes made to the tty settings by

external programs will be honored by the shell, except for

changes in the size of the screen; the shell will simply reset

the settings to their previous values as soon as each command ex

its or is suspended. Thus, stty and similar programs have no ef

fect when the tty is frozen. Without options it reports whether

the terminal is frozen or not.

type [ -fpam ] name ...

Same as whence -v.

typeset [ ±LRUZfilrtuxm [n]] [ name[=value] ] ...

Set attributes and values for shell parameters.

When invoked inside a function a new parameter is created which

will be unset when the function completes. The new parameter

will not be exported unless ALLEXPORT is set, in which case the

parameter will be exported provided no parameter of that name al

ready exists. The following attributes are valid:
-L Left justify and remove leading blanks from

value. If n is nonzero, it defines the width of the field; oth

erwise it is determined by the width of the value of the first

assignment. When the parameter is printed, it is filled on the

right with blanks or truncated if necessary to fit the field.

Leading zeros are removed if the -Z flag is also set.
-R Right justify and fill with leading blanks.

If n is nonzero if defines the width of the field; otherwise it

is determined by the width of the value of the first assignment.

When the parameter is printed, the field is left filled with

blanks or truncated from the end.
-U For arrays keep only the first element of

each duplications. It can also be set for colon separated special

parameters like PATH or FIGNORE, etc.
-Z Right justify and fill with leading zeros if

the first non-blank character is a digit and the -L flag has not

been set. If n is nonzero it defines the width of the field;

otherwise it is determined by the width of the value of the first

assignment.
-f The names refer to functions rather than pa

rameters. No assignments can be made, and the only other valid

flags are -t and -u. The flag -t turns on execution tracing for

this function. The flag -u causes this function to be marked for

autoloading. The fpath parameter will be searched to find the

function definition when the function is first referenced; see

autoload.
-i Use an internal integer representation. If

n is nonzero it defines the output arithmetic base, otherwise it

is determined by the first assignment.
-l Convert to lower case.
-r The given names are marked readonly.
-t Tags the named parameters. Tags have no

special meaning to the shell.
-u Convert to upper case.
-x Mark for automatic export to the environment

of subsequently executed commands.

Using + rather than - causes these flags to be

turned off.
If no arguments are given but flags are specified,

a list of named parameters which have these flags set is printed.

Using + instead of - keeps their values from being printed. If

no arguments or options are given, the names and attributes of

all parameters are printed. If only the -m flag is given the ar

guments are taken as patterns (should be quoted) and all parame

ters or functions (with the -f flag) with matching names are

printed.

ulimit [ -SHacdflmnpstv ] [ limit ] ...

Set or display resource limits of the shell and the

processes started by the shell. The value of limit can be a num

ber in the unit specified below or the value unlimited. 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 as

sumed. If limit is omitted the current value of the specified

resources are printed. When more than one resource values are

printed the limit name and unit is printed before each value.
-a Lists all of the current resource limits.
-c The number of 512-byte blocks on the size of

core dumps.
-d The number of K-bytes on the size of the da

ta segment.
-f The number of 512-byte blocks on the size of

files written.
-l The number of K-bytes on the size of locked

in memory.
-m The number of K-bytes on the size of physi

cal memory.
-n The number of open file descriptors.
-s The number of K-bytes on the size of the

stack.
-t The number of CPU seconds to be used.
-u The number of processes available to the us

er.
-v The number of K-bytes on the size of virtual

memory.

umask [ -S ] [ mask ]

The umask is set to mask. mask can be either an

octal number or a symbolic value as described in chmod(1). If

mask is omitted, the current value is printed. The -S option

causes the mask to be printed as a symbolic value. Otherwise,

the mask is printed as an octal number. Note that in the symbol

ic form the permissions you specify are those which are to be al

lowed (not denied) to the users specified.

unalias [ -m ] name ...

The alias definition, if any, for each name is re

moved. With the -m flag the arguments are taken as patterns

(should be quoted) and all aliases with names matching the pat

terns are removed. unalias is equivalent to unhash -a.

unfunction [ -m ] name ...

The function definition, if any, for each name is

removed. If the -m flag is specified the arguments are taken as

patterns (should be quoted) and all functions with names matching

the patterns are removed. unfunction is equivalent to unhash -f.

unhash [ -adfm ] name ...

Remove the element named name from an internal hash

table. The default is remove elements from the command hash ta

ble. The -a option causes unhash to remove aliases. The -f op

tion 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 is running as

root, the hard resource limit for each resource is removed. The

resources of the shell process are only changed if the -s flag is

given.

unset [ -fm ] name ...

Each named parameter is unset. If the -m flag is

specified the arguments are taken as patterns (should be quoted)

and all parameters with matching names are unset. Unset -f is

equivalent to unfunction.

unsetopt [ ±options ] [ name ... ]

Unset the options for the shell. All options spec

ified either with flags or by name are unset. If the -m flag is

given the arguments are considered to be patterns (don't forget

to quote them) and all options with names matching these patterns

are unset.

vared [ -c ] [ -h ] [ -p prompt ] [ -r rprompt ] name

The value of the parameter name is loaded into the

edit buffer, and the line editor is invoked. When the editor ex

its, name is set to the string value returned by the editor. If

the -c flag is given the parameter is created if it doesn't al

ready exist. If the -p flag is given the following string will

be taken as the prompt to display at the left and if the -r flag

is given the following string gives the prompt to display at the

right. If the -h flag is specified, the history can be accessed

from zle.

wait [ job ... ]

Wait for the specified jobs or processes. If job

is not given then all currently active child processes are waited

for. Each job can be either a job specification or the process

id of a job in the job table. The exit status from this command

is that of the job waited for.

whence [ -vcfpam ] name ...

For each name, indicate how it would be interpreted

if used as a command name. The -v flag produces a more verbose

report. The -c flag prints the results in a csh-like format, and

takes precedence over -v. The -f flag causes the contents of a

shell function to be displayed, which would otherwise not happen

unless the -c flag were used. The -p flag does a path search for

name even if it is an alias, reserved word, shell function or

builtin. The -a flag does a search for all occurrences of name

throughout the command path. With the -m flag the arguments are

taken as patterns (should be quoted) and the information is dis

played for each command matching one of these patterns.

where Same as whence -ca.

which [ -pam ] name ...

Same as whence -c.

zsh version 3.0 June 26, 1996

ZSHBUILTINS(1)