The Z Shell Guide
*****************

This Info file documents Zsh, a freely available UNIX command interpreter (shell), which of the standard shells most closely resembles the Korn shell (ksh), although it is not completely compatible.

Version 3.1.5, last updated October 29, 1998.

The Z Shell Guide
*****************

This document has been produced from the texinfo file zsh.texi, included in the Doc sub-directory of the Zsh distribution.

Producing documentation from zsh.texi
=====================================

The texinfo source may be converted into several formats:

The Info guide
     The Info format allows searching for topics, commands, functions, etc. from the many Indices. The command `makeinfo zsh.texi' is used to produce the Info documentation.

The printed guide
     The command `texi2dvi zsh.texi' will output zsh.dvi which can then be processed with dvips and optionally gs (Ghostscript) to produce a nicely formatted printed guide.

The HTML guide
     Mark Borges, <mdb@cdc.noaa.gov, maintains an HTML version of this guide at http://www.peak.org/zsh/Doc/zsh_toc.html. (The HTML version is produced with texi2html, which may be obtained from http://wwwcn.cern.ch/dci/texi2html/. The command is `texi2html -split_chapter -expandinfo zsh.texi'.)

For those who do not have the necessary tools to process texinfo, precompiled documentation (PostScript, dvi, info and HTML formats) is available from the zsh archive site or its mirrors, in the file zsh-doc.tar.gz. (See Availability for a list of sites.)

Introduction
************

Zsh is a UNIX command interpreter (shell) usable as an interactive login shell and as a shell script command processor.  Of the standard shells, zsh most closely resembles ksh but includes many enhancements.  Zsh has command line editing, builtin spelling correction, programmable command completion, shell functions (with autoloading), a history mechanism, and a host of other features.

Author
======

Zsh was originally written by Paul Falstad <pf@zsh.org>. Zsh is now maintained by the members of the zsh-workers mailing list <zsh-workers@math.gatech.edu>.  The development is currently coordinated by Andrew Main (Zefram) <zefram@zsh.org>.  The coordinator can be contacted at <coordinator@zsh.org>, but matters relating to the code should generally go to the mailing list.

Availability
============

Zsh is available from the following anonymous FTP sites.  These mirror sites are kept frequently up to date.  The sites marked with (G) may be mirroring ftp.math.gatech.edu instead of the primary site. The sites marked with (H) may be mirroring ftp.cs.elte.hu instead of the primary site.

Primary site
     ftp://ftp.zsh.org/pub/zsh/

     http://www.zsh.org/pub/zsh/

Australia
     ftp://ftp.zsh.org/pub/zsh/

     http://www.zsh.org/pub/zsh/

     ftp://ftp.ips.oz.au/pub/packages/zsh/  (G)  (H)

Denmark
     ftp://sunsite.auc.dk/pub/unix/shells/zsh/

Finland
     ftp://ftp.funet.fi/pub/unix/shells/zsh/  (H)

France
     ftp://ftp.cenatls.cena.dgac.fr/pub/shells/zsh/

Germany
     ftp://ftp.fu-berlin.de/pub/unix/shells/zsh/  (H)

     ftp://ftp.gmd.de/packages/zsh/  (H)

     ftp://ftp.uni-trier.de/pub/unix/shell/zsh/  (H)

Hungary
     ftp://ftp.cs.elte.hu/pub/zsh/

     http://www.cs.elte.hu/pub/zsh/

     ftp://ftp.kfki.hu/pub/packages/zsh/  (H)

Israel
     ftp://ftp.math.technion.ac.il/mirror/ftp.zsh.org/pub/zsh/

     http://www.math.technion.ac.il/mirror/ftp.zsh.org/pub/zsh/

Japan
     ftp://ftp.tohoku.ac.jp/mirror/zsh/  (H)

     ftp://ftp.nis.co.jp/pub/shells/zsh/  (H)

Norway
     ftp://ftp.uit.no/pub/unix/shells/zsh/  (H)

Romania
     ftp://ftp.roedu.net/pub/mirrors/ftp.zsh.org/pub/zsh/

Slovenia
     ftp://ftp.siol.net/pub/unix/shells/zsh/  (H)

Sweden
     ftp://ftp.lysator.liu.se/pub/unix/zsh/  (H)

UK
     ftp://ftp.net.lut.ac.uk/zsh/  (H)

     ftp://sunsite.doc.ic.ac.uk/packages/unix/shells/zsh/  (G)

USA
     ftp://ftp.math.gatech.edu/pub/zsh/

     ftp://uiarchive.uiuc.edu/pub/packages/shells/zsh/

     ftp://ftp.sterling.com/zsh/  (G)  (H)

     ftp://ftp.rge.com/pub/shells/zsh/  (G)  (H)

     ftp://foad.org/pub/zsh/

     http://foad.org/zsh/

Mailing Lists
=============

Zsh has 3 mailing lists:

<zsh-announce@math.gatech.edu>
     Announcements about releases, major changes in the shell and the monthly posting of the Zsh FAQ.  (moderated)

<zsh-users@math.gatech.edu>
     User discussions.

<zsh-workers@math.gatech.edu>
     Hacking, development, bug reports and patches.

To subscribe, send mail with the SUBJECT `subscribe <E-MAIL-ADDRESS>' to the associated administrative address for the mailing list.

<zsh-announce-request@math.gatech.edu>

<zsh-users-request@math.gatech.edu>

<zsh-workers-request@math.gatech.edu>

Unsubscribing is done similarly.

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

If you have problems subscribing/unsubscribing to any of the mailing lists, send mail to <listmaster@zsh.org>.  The mailing lists are maintained by Richard Coleman <coleman@zsh.org>.

The mailing lists are archived; the archives can be accessed via the administrative addresses listed above.  There is also a hypertext archive, maintained by Geoff Wing <gcw@zsh.org>, available at http://www.zsh.org/mla/.

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

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

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

Zsh has a web page which is located at http://www.zsh.org/.  This is maintained by Karsten Thygesen <karthy@zsh.org>, of SunSITE Denmark. The contact address for web-related matters is <webmaster@zsh.org>.

See Also
========

man page sh(1), man page csh(1), man page tcsh(1), man page rc(1), man page bash(1), man page ksh(1)

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

Invocation
**********

Invocation Options
==================

If the -s flag is not present and an argument is given, the first argument is taken to be the pathname of a script to execute.  The remaining arguments are assigned to the positional parameters.  The following flags are interpreted by the shell when invoked:

-c STRING
     Read commands from STRING.

-i
     Force shell to be interactive.

-s
     Read command from the standard input.

Files
*****

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

Commands are first read from /etc/zshenv. If the RCS option is unset within /etc/zshenv, all other initialization files are skipped. Otherwise, commands are read from $ZDOTDIR/.zshenv. If the shell is a login shell, commands are read from /etc/zprofile and then $ZDOTDIR/.zprofile. Then, if the shell is interactive, commands are read from /etc/zshrc and then $ZDOTDIR/.zshrc. Finally, if the shell is a login shell, /etc/zlogin and $ZDOTDIR/.zlogin are read.

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

Files
=====

$ZDOTDIR/.zshenv

$ZDOTDIR/.zprofile

$ZDOTDIR/.zshrc

$ZDOTDIR/.zlogin

$ZDOTDIR/.zlogout

${TMPPREFIX}*   (default is /tmp/zsh*)

/etc/zshenv

/etc/zprofile

/etc/zshrc

/etc/zlogin

/etc/zlogout   (installation-specific - /etc is the default)

Shell Grammar
*************

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

A simple command is a sequence of optional parameter assignments followed by blank-separated words, with optional redirections interspersed. The first word is the command to be executed, and the remaining words, if any, are arguments to the command. If a command name is given, the parameter assignments modify the environment of the command when it is executed. The value of a simple command is its exit status, or 128 plus the signal number if terminated by a signal.

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

If a pipeline is preceded by `coproc', it is executed as a coprocess; a two-way pipe is established between it and the parent shell.  The shell can read from or write to the coprocess by means of the `>&p' and `<&p' redirection operators or with `print -p' and `read -p'. A pipeline cannot be preceded by both `coproc' and `!'.

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

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

Precommand Modifiers
====================

A simple command may be preceded by a precommand modifier, which will alter how the command is interpreted.  These modifiers are shell builtin commands with the exception of nocorrect which is a reserved word.

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

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

nocorrect
     Spelling correction is not done on any of the words.

exec
     The command is executed in the parent shell without forking.

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

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

Complex Commands
================

A complex command in zsh is one of the following:

if LIST then LIST [ elif LIST then LIST ] ... [ else LIST ] fi
     The if LIST is executed, and if it returns a zero exit status, the then LIST is executed. Otherwise, the elif LIST is executed and if its value is zero, the then LIST is executed. If each elif LIST returns nonzero, the else LIST is executed.

for NAME [ in WORD ... TERM ] do LIST done
     where TERM is at least one newline or ;. Expand the list of WORDs, and set the parameter NAME to each of them in turn, executing LIST each time.  If the in WORD is omitted, use the positional parameters instead of the WORDs.

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

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

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

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

case WORD in [ [(] PATTERN [ | PATTERN ] ... ) LIST (;;|;&) ] ... esac
     Execute the LIST associated with the first PATTERN that matches WORD, if any.  The form of the patterns is the same as that used for filename generation.  See Filename Generation. If the LIST that is executed is terminated with ;& rather than ;;, the following list is also executed.  This continues until either a list is terminated with ;; or the esac is reached.

select NAME [ in WORD ... TERM ] do LIST done
     where TERM is one ore more newline or ;. Print the set of WORDs, each preceded by a number. If the in WORD is omitted, use the positional parameters. The PROMPT3 prompt is printed and a line is read from standard input.  If this line consists of the number of one of the listed WORDs, then the parameter NAME is set to the WORD corresponding to this number. If this line is empty, the selection list is printed again. Otherwise, the value of the parameter NAME is set to null. The contents of the line read from standard input is saved in the parameter REPLY.  LIST is executed for each selection until a break or end-of-file is encountered.

( LIST )
     Execute LIST in a subshell.  Traps set by the trap builtin are reset to their default values while executing LIST.

{ LIST }
     Execute LIST.

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

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

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

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

Many of zsh's complex commands have alternate forms.  These particular versions of complex commands should be considered deprecated and may be removed in the future.  The versions in the previous section should be preferred instead.  The short versions below only work if SUBLIST is of the form `{ LIST }' or if the SHORT_LOOPS option is set.

if LIST { LIST } [ elif LIST { LIST } ] ... [ else { LIST } ]
     An alternate form of if.

if LIST SUBLIST
     A short form of the alternate `if'.

for NAME ( WORD ... ) SUBLIST
     A short form of for.

for NAME [ in WORD ... TERM ] SUBLIST
     where TERM is at least one newline or ;. Another short form of for.

for (( [EXPR1] ; [EXPR2] ; [EXPR3] )) SUBLIST
     A short form of the arithmetic for command.

foreach NAME ( WORD ... ) LIST end
     Another form of for.

while LIST { LIST }
     An alternative form of while.

until LIST { LIST }
     An alternative form of until.

repeat WORD SUBLIST
     This is a short form of repeat.

case WORD { [ [(] PATTERN [ | PATTERN ] ... ) LIST (;;|;&) ] ... }
     An alternative form of case.

select NAME [ in WORD TERM ] SUBLIST
     where TERM is at least one newline or ;. A short form of select.

Reserved Words
==============

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

do done esac then elif else fi for case if while function repeat time until select coproc nocorrect foreach end ! [[ { }

Additionally, `}' is recognized in any position if the IGNORE_BRACES option is not set.

Comments
========

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

Aliasing
========

Every token in the shell input is checked to see if there is an alias defined for it. If so, it is replaced by the text of the alias if it is in command position (if it could be the first word of a simple command), or if the alias is global. If the text ends with a space, the next word in the shell input is treated as though it were in command position for purposes of alias expansion. An alias is defined using the alias builtin; global aliases may be defined using the -g option to that builtin.

Alias substitution is done on the shell input before any other substitution except history substitution.  Therefore, if an alias is defined for the word foo, alias substitution may be avoided by quoting part of the word, e.g. \foo. But there is nothing to prevent an alias being defined for \foo as well.

Quoting
=======

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

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

All characters enclosed between a pair of single quotes that is not preceded by a `$' are quoted.  A single quote cannot appear within single quotes.

Inside double quotes (""), parameter and command substitution occurs, and `\' quotes the characters `\', ``', `"', and `$'.

Redirection
***********

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

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

< WORD
     Open file WORD for reading as standard input.

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

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

>| WORD
>! WORD
     Same as >, except that the file is truncated to zero length if it exists, even if CLOBBER is unset.

>> WORD
     Open file WORD for writing in append mode as standard output. If the file does not exist, and the CLOBBER option is unset, this causes an error; otherwise, the file is created.

>>| WORD
>>! WORD
     Same as >>, except that the file is created if it does not exist, even if CLOBBER is unset.

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

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

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

<<< WORD
     Perform shell expansion on WORD and pass the result to standard input.  This is known as a here-string.

<& DIGIT
>& DIGIT
     The standard input/output is duplicated from file descriptor DIGIT (see man page dup(2)).

<& -
>& -
     Close the standard input/output.

<& p
>& p
     The input/output from/to the coprocess is moved to the standard input/output.

>& WORD
     Same as `> WORD 2>&1'.

>>& WORD
     Same as `>> WORD 2>&1'.

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

... 1>FNAME 2>&1

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

Multios
=======

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

date >foo >bar

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

date >foo | cat

writes the date to the file `foo', and also pipes it to cat.

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

: > *

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

echo exit 0 >> *.sh

If the user tries to open a file descriptor for reading more than once, the shell opens the file descriptor as a pipe to a process that copies all the specified inputs to its output in the order specified, similar to cat, provided the MULTIOS option is set.  Thus

sort <foo <fubar

or even

sort <f{oo,ubar}

is equivalent to `cat foo fubar | sort'.

Note that a pipe is an implicit redirection; thus

cat bar | sort <foo

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

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

echo foo > bar > baz

when MULTIOS is unset will truncate bar, and write `foo' into baz.

If a simple command consists of one or more redirection operators and zero or more parameter assignments, but no command name, the command named in the shell variable READNULLCMD is assumed. (If READNULLCMD is empty or not set, `cat' is used.)  Thus

< file

prints the contents of file.

Command Execution
*****************

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

Otherwise, the shell searches each element of $path for a directory containing an executable file by that name.  If the search is unsuccessful, the shell prints an error message and returns a nonzero exit status.

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

Functions
*********

The function reserved word is used to define shell functions. Shell functions are read in and stored internally. Alias names are resolved when the function is read. Functions are executed like commands with the arguments passed as positional parameters. (See Command Execution.)

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

The return builtin is used to return from function calls.

Function identifiers can be listed with the functions builtin. Functions can be undefined with the unfunction builtin.

Autoloading Functions
=====================

A function can be marked as undefined using the autoload builtin (or `functions -u' or `typeset -fu').  Such a function has no body.  When the function is first executed, the fpath variable will be searched for a file with the same name as the function.

If the KSH_AUTOLOAD option is set, or the file contains only a simple definition of the function, the file's contents will be executed.  It would normally define the function in question, but may also perform initialisation. It is executed in the context of the function execution, and may therefore define local parameters.

Otherwise, the function is defined such that its body is the complete contents of the file.  This form allows the file to be used directly as an executable shell script. Initialisation code can be executed, but only as part of the first function execution, so the function would have to redefine itself to avoid reinitialising on the next execution.

If this processing of the file results in the function being fully defined, the function itself is then executed.

Special Functions
=================

The following functions, if defined, have special meaning to the shell:

chpwd
     Executed whenever the current working directory is changed.

periodic
     If the parameter PERIOD is set, this function is executed every $PERIOD seconds, just before a prompt.

precmd
     Executed before each prompt.

preexec
     Executed just after a command has been read and is about to be executed.  If the history mechanism is active, the string to be executed is passed as an argument.

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

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

TRAPDEBUG
     Executed after each command.

TRAPEXIT
     Executed when the shell exits, or when the current function exits if defined inside a function.

TRAPZERR
     Executed whenever a command has a non-zero exit status.

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

Jobs
====

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

[1] 1234

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

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

If you are running a job and wish to do something else you may hit the key ^Z (control-Z) which sends a TSTP signal to the current job. The shell will then normally indicate that the job has been `suspended', and print another prompt.  You can then manipulate the state of this job, putting it in the background with the bg command, or run some other commands and then eventually bring the job back into the foreground with the foreground command fg.  A ^Z takes effect immediately and is like an interrupt in that pending output and unread input are discarded when it is typed.

A job being run in the background will suspend if it tries to read from the terminal. Background jobs are normally allowed to produce output, but this can be disabled by giving the command `stty tostop'. If you set this tty option, then background jobs will suspend when they try to produce output like they do when they try to read input.

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

%NUMBER
     The job with the given number.

%STRING
     Any job whose command line begins with STRING.

%?STRING
     Any job whose command line contains STRING.

%%
     Current job.

%+
     Equivalent to `%%'.

%-
     Previous job.

The shell learns immediately whenever a process changes state. It normally informs you whenever a job becomes blocked so that no further progress is possible.  If the NOTIFY option is not set, it waits until just before it prints a prompt before it informs you.

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

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

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

Signals
=======

The INT and QUIT signals for an invoked command are ignored if the command is followed by `&' and the MONITOR option is not active. Otherwise, signals have the values inherited by the shell from its parent (but see the TRAPNAL special functions in Functions).

Arithmetic Evaluation
*********************

An ability to perform integer arithmetic is provided with the builtin let. Evaluations are performed using long arithmetic. A leading `0x' or `0X' denotes hexadecimal. Otherwise, numbers are of the form `[BASE#]N', where BASE is a decimal number between two and thirty-six representing the arithmetic base and N is a number in that base (for example, `16#ff' is 255 in hexadecimal). If BASE is omitted then base 10 is used.  For backwards compatibility the form `[BASE]N' is also accepted.

An arithmetic expression uses nearly the same syntax, precedence, and associativity of expressions in C. The following operators are supported (listed in decreasing order of precedence):

+ - ! ~ ++ --
     unary plus/minus, logical NOT, complement, {pre,post}{in,de}crement

<< >>
     bitwise shift left, right

&
     bitwise AND

^
     bitwise XOR

|
     bitwise OR

**
     exponentiation

* / %
     multiplication, division, modulus (remainder)

+ -
     addition, subtraction

< > <= >=
     comparison

== !=
     equality and inequality

&&
     logical AND

|| ^^
     logical OR, XOR

? :
     ternary operator

= += -= *= /= %= &= ^= |= <<= >>= &&= ||= ^^= **=
     assignment

,
     comma operator

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

An expression of the form `#\X' where X is any character gives the ascii value of this character and an expression of the form `#FOO' gives the ascii value of the first character of the value of the parameter FOO.

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

An internal integer representation of a named parameter can be specified with the integer builtin. Arithmetic evaluation is performed on the value of each assignment to a named parameter declared integer in this manner.

Since many of the arithmetic operators require quoting, an alternative form of the let command is provided. For any command which begins with a ((, all the characters until a matching )) are treated as a quoted expression. More precisely, `(( ... ))' is equivalent to `let "..."'.

Conditional Expressions
***********************

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

-a FILE
     true if FILE exists.

-b FILE
     true if FILE exists and is a block special file.

-c FILE
     true if FILE exists and is a character special file.

-d FILE
     true if FILE exists and is a directory.

-e FILE
     true if FILE exists.

-f FILE
     true if FILE exists and is a regular file.

-g FILE
     true if FILE exists and has its setgid bit set.

-h FILE
     true if FILE exists and is a symbolic link.

-k FILE
     true if FILE exists and has its sticky bit set.

-n STRING
     true if length of STRING is non-zero.

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

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

-r FILE
     true if FILE exists and is readable by current process.

-s FILE
     true if FILE exists and has size greater than zero.

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

-u FILE
     true if FILE exists and has its setuid bit set.

-w FILE
     true if FILE exists and is writable by current process.

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

-z STRING
     true if length of STRING is zero.

-L FILE
     true if FILE exists and is a symbolic link.

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

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

-S FILE
     true if FILE exists and is a socket.

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

FILE1 -nt FILE2
     true if FILE1 exists and is newer than FILE2.

FILE1 -ot FILE2
     true if FILE1 exists and is older than FILE2.

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

STRING = PATTERN
STRING == PATTERN
     true if STRING matches PATTERN. The `==' form is the preferred one.  The `=' form is for backward compatibility and should be considered obsolete.

STRING != PATTERN
     true if STRING does not match PATTERN.

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

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

EXP1 -eq EXP2
     true if EXP1 is numerically equal to EXP2.

EXP1 -ne EXP2
     true if EXP1 is numerically not equal to EXP2.

EXP1 -lt EXP2
     true if EXP1 is numerically less than EXP2.

EXP1 -gt EXP2
     true if EXP1 is numerically greater than EXP2.

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

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

( EXP )
     true if EXP is true.

! EXP
     true if EXP is false.

EXP1 && EXP2
     true if EXP1 and EXP2 are both true.

EXP1 || EXP2
     true if either EXP1 or EXP2 is true.

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

Compatibility
*************

Zsh tries to emulate sh or ksh when it is invoked as sh or ksh respectively.  In this mode the following parameters are not special and not initialized by the shell: ARGC, argv, cdpath, fignore, fpath, HISTCHARS, mailpath, MANPATH, manpath, path, prompt, PROMPT, PROMPT2, PROMPT3, PROMPT4, psvar, status, watch.

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

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

Prompt Expansion
****************

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

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

Certain escape sequences may be recognised in the prompt string.

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

If the PROMPT_PERCENT option is set, certain escape sequences that start with `%' are expanded. Some escapes take an optional integer argument, which should appear between the `%' and the next character of the sequence.  The following escape sequences are recognized:

%%
     A `%'.

%)
     A `)'.

%d
%/
     Present working directory ($PWD).

%~
     $PWD. If it has a named directory as its prefix, that part is replaced by a `~' followed by the name of the directory. If it starts with $HOME, that part is replaced by a `~'.

%c
%.
%C
     Trailing component of $PWD. An integer may follow the `%' to get more than one component. Unless `%C' is used, tilde contraction is performed first.

%h
%!
     Current history event number.

%L
     The current value of $SHLVL.

%M
     The full machine hostname.

%m
     The hostname up to the first `.'. An integer may follow the `%' to specify how many components of the hostname are desired.

%S (%s)
     Start (stop) standout mode.

%U (%u)
     Start (stop) underline mode.

%B (%b)
     Start (stop) boldface mode.

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

%T
     Current time of day, in 24-hour format.

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

%n
     $USERNAME.

%w
     The date in DAY-DD format.

%W
     The date in MM/DD/YY format.

%D
     The date in YY-MM-DD format.

%D{STRING}
     STRING is formatted using the strftime function. See man page strftime(3) for more details.  Three additional codes are available:  %f prints the day of the month, like %e but without any preceding space if the day is a single digit, and %K/%L correspond to %k/%l for the hour of the day (24/12 hour clock) in the same way.

%l
     The line (tty) the user is logged in on.

%?
     The return code of the last command executed just before the prompt.

%_
     The status of the parser, i.e. the shell constructs (like `if' and `for') that have been started on the command line. If given an integer number that many strings will be printed; zero or no integer means print as many as there are.

%E
     Clears to end of line.

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

%v
     The value of the first element of the psvar array parameter.  Following the `%' with an integer gives that element of the array.

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

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

     The left parenthesis may be preceded or followed by a positive integer N, which defaults to zero.  The test character X may be any of the following:

     c
     .
     ~
          True if the current path, with prefix replacement, has at least N elements.

     /
     C
          True if the current absolute path has at least N elements.

     t
          True if the time in minutes is equal to N.

     T
          True if the time in hours is equal to N.

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

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

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

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

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

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

     L
          True if the SHLVL parameter is at least N.

     S
          True if the SECONDS parameter is at least N.

     v
          True if the array psvar has at least N elements.

     _
          True if at least N shell constructs were started.

     !
          True if the shell is running with privileges.

%<STRING<
%>STRING>
%[XSTRING]
     Specifies truncation behaviour. The third, deprecated, form is equivalent to `%XSTRINGX', i.e. X may be `<' or `>'. The numeric argument, which in the third form may appear immediately after the `[', specifies the maximum permitted length of the various strings that can be displayed in the prompt.  If this integer is zero, or missing, truncation is disabled.  Truncation is initially disabled. The STRING will be displayed in place of the truncated portion of any string.

     The forms with `<' truncate at the left of the string, and the forms with `>' truncate at the right of the string. For example, if the current directory is `/home/pike', the prompt `%8<..<%/' will expand to `..e/pike'. In this string, the terminating character (`<', `>' or `]'), or in fact any character, may be quoted by a preceding `\'. % escapes are not recognised. If the STRING is longer than the specified truncation length, it will appear in full, completely replacing the truncated string.

Restricted Shell
****************

When the basename of the command used to invoke zsh starts with the letter `r' or the `-r' command line option is supplied at invocation, the shell becomes restricted.  Emulation mode is determined after stripping the letter `r' from the invocation name.  The following are disabled in restricted mode:

  * changing directories with the cd builtin

  * changing or unsetting the PATH, path, MODULE_PATH, module_path, SHELL, HISTFILE, HISTSIZE, GID, EGID, UID, EUID, USERNAME, LD_LIBRARY_PATH, LD_AOUT_LIBRARY_PATH, LD_PRELOAD and  LD_AOUT_PRELOAD parameters

  * specifying command names containing /

  * specifying command pathnames using hash

  * redirecting output to files

  * using the exec builtin command to replace the shell with another command

  * using jobs -Z to overwrite the shell process' argument and environment space

  * using the ARGV0 parameter to override argv[0] for external commands

  * turning off restricted mode with set +r or unsetopt RESTRICTED

  * specifying modules to be loaded with an explicitly given pathname containing slashes

These restrictions are enforced after processing the startup files.  The startup files should set up PATH to point to a directory of commands which can be safely invoked in the restricted environment.  They may also add further restrictions by disabling selected builtins.

Restricted mode can also be activated any time by setting the RESTRICTED option.  This immediately enables all the restrictions described above even if the shell still have not processed all startup files.

Expansion
*********

Description
===========

The types of expansions performed are

history expansion

alias expansion

process substitution

parameter expansion

command substitution

arithmetic expansion

brace expansion

filename expansion

filename generation

Expansion is done in the above specified order in five steps.  The first is history expansion, which is only performed in interactive shells.  The next step is alias expansion, which is done right before the command line is parsed.  They are followed by process substitution, parameter expansion, command substitution, arithmetic expansion and brace expansion which are performed in one step in left-to-right fashion.  After these expansions, all unquoted occurrences of the characters `\', `'' and `"' are removed, and the result is subjected to filename expansion followed by filename generation.

If the SH_FILE_EXPANSION option is set, the order of expansion is modified for compatibility with sh and ksh.  Filename expansion is performed immediately after alias substitution, preceding the set of five substitutions mentioned above.

History Expansion
=================

History expansion allows you to use words from previous command lines in the command line you are typing.  This simplifies spelling corrections and the repetition of complicated commands or arguments. Command lines are saved in the history list, the size of which is controlled by the HISTSIZE variable.  The most recent command is retained in any case. A history expansion begins with the first character of the histchars parameter which is `!' by default and may occur anywhere on the command line; history expansions do not nest.  The `!' can be escaped with `\' or can be enclosed between a pair of single quotes to suppress its special meaning. Double quotes will not work for this.

Input lines containing history expansions are echoed on the terminal after being expanded, but before any other expansions take place or the command gets executed.

Event Designators
-----------------

An event designator is a reference to a command-line entry in the history list.

!
     Start a history expansion, except when followed by a blank, newline, `=' or `('.

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

!N
     Refer to command-line N.

!-N
     Refer to the current command-line minus N.

!STR
     Refer to the most recent command starting with STR.

!?STR[?]
     Refer to the most recent command containing STR.

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

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

Word Designators
----------------

A word designator indicates which word or words of a given command line will be included in a history reference.  A `:' separates the event specification from the word designator. It can be omitted if the word designator begins with a `^', `$', `*', `-' or `%'. Word designators include:

0
     The first input word (command).

N
     The Nth argument.

^
     The first argument.  That is, 1.

$
     The last argument.

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

X-Y
     A range of words; X defaults to 0.

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

X*
     Abbreviates `X-$'.

X-
     Like `X*' but omitting word $.

Note that a `%' word designator will only work when used as `!%', `!:%' or `!?STR?:%', and only when used after a !? expansion.  Anything else will result in an error, although the error may not be the most obvious one.

Modifiers
---------

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

h
     Remove a trailing pathname component, leaving the head.

r
     Remove a trailing suffix of the form `.XXX', leaving the basename.

e
     Remove all but the suffix.

t
     Remove all leading pathname components, leaving the tail.

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

q
     Quote the substituted words, escaping further substitutions.  Only works with history expansion.

x
     Like q, but break into words at each blank.

l
     Convert the words to all lowercase.

u
     Convert the words to all uppercase.

f
     (This and the following F, w and W modifier only work with parameter and filename expansion.) Repeats the immediately (without a colon) following modifier until the resulting word doesn't change any more.

F:EXPR:
     Like f, but repeats only N times if the expression EXPR evaluates to N.  Any character can be used instead of the `:', if any of `(', `[', or `{' is used as the opening delimiter the second one has to be ')', `]', or `}' respectively.

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

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

s/L/R[/]
     Substitute R for L as described below. Unless preceded immediately by a g, with no colon between, the substitution is done only for the first string that matches L.  For arrays and filename expansion, this applies to each word of the expanded text.

&
     Repeat the previous s substitution.  Like s, may be preceded immediately by a g.  In variable expansion the & must appear inside braces, and in filename expansion it must be quoted with a backslash.

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

By default, a history reference with no event specification refers to the same line as the last history reference on that command line, unless it is the first history reference in a command.  In that case, a history reference with no event specification always refers to the previous command.  However, if the option CSH_JUNKIE_HISTORY is set, then history reference with no event specification will always refer to the previous command.

For example, `!!:1' will always refer to the first word of the previous command, and `!!$' will always refer to the last word of the previous command.  And with CSH_JUNKIE_HISTORY set, then `!:1' and `!$' will function in the same manner as `!!:1' and `!!$', respectively.  However, if CSH_JUNKIE_HISTORY is unset, then `!:1' and `!$' will refer to the first and last words respectively, of the last command referenced on the current command line.  However, if they are the first history reference on the command line, then they refer to the previous command.

The character sequence `^FOO^BAR' repeats the last command, replacing the string FOO with BAR.

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

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

Process Substitution
====================

Each command argument of the form `<(LIST)', `>(LIST)' or `=(LIST)' is subject to process substitution. In the case of the < or > forms, the shell will run process LIST asynchronously, connected to a named pipe (FIFO). The name of this pipe will become the argument to the command. If the form with > is selected then writing on this file will provide input for LIST. If < is used, then the file passed as an argument will be a named pipe connected to the output of the LIST process. For example,

paste <(cut -f1 FILE1) <(cut -f3 FILE2) | tee >(PROCESS1) >(PROCESS2) >/dev/null

cuts fields 1 and 3 from the files FILE1 and FILE2 respectively, pastes the results together, and sends it to the processes PROCESS1 and PROCESS2. Note that the file, which is passed as an argument to the command, is a system pipe, so programs that expect to lseek (see man page lseek(2)) on the file will not work. Also note that the previous example can be more compactly and efficiently written as:

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

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

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

Parameter Expansion
===================

The character `$' is used to introduce parameter expansions. See Parameters for a description of parameters. In the expansions discussed below that require a pattern, the form of the pattern is the same as that used for filename generation; see Filename Generation.  In addition to the following operations, the file modifiers described in Modifiers in History Expansion can be applied:  for example, ${i:s/foo/bar/} performs string substitution on the value of parameter $i.

${NAME}
     The value, if any, of the parameter NAME is substituted. The braces are required if NAME is followed by a letter, digit, or underscore that is not to be interpreted as part of its name.

     If NAME is an array parameter, then the values of each element of NAME is substituted, one element per word. Otherwise, the expansion results in one word only; no field splitting is done on the result unless the SH_WORD_SPLIT option is set.

${+NAME}
     If NAME is the name of a set parameter `1' is substituted, otherwise `0' is substituted.

${NAME:-WORD}
     If NAME is set and is non-null then substitute its value; otherwise substitute WORD. If NAME is missing, substitute WORD.

${NAME:=WORD}
     If NAME is unset or is null then set it to WORD; the value of the parameter is then substituted.

${NAME:?WORD}
     If NAME is set and is non-null, then substitute its value; otherwise, print WORD and exit from the shell. If WORD is omitted, then a standard message is printed.

${NAME:+WORD}
     If NAME is set and is non-null then substitute WORD; otherwise substitute nothing.

If the colon is omitted from one of the above expressions containing a colon, then the shell only checks whether NAME is set or not, not whether it is null.

${NAME::=WORD}
     Set NAME to WORD; the value of the parameter is then substituted.

${NAME#PATTERN}
${NAME##PATTERN}
     If the PATTERN matches the beginning of the value of NAME, then substitute the value of NAME with the matched portion deleted; otherwise, just substitute the value of NAME.  In the first form, the smallest matching pattern is preferred; in the second form, the largest matching pattern is preferred. If NAME is an array and the substitution is not quoted or the (@) flag or the `NAME[@]' syntax is used, matching is performed on each array elements separately.

${NAME%PATTERN}
${NAME%%PATTERN}
     If the PATTERN matches the end of the value of NAME, then substitute the value of NAME with the matched portion deleted; otherwise, just substitute the value of NAME.  In the first form, the smallest matching pattern is preferred; in the second form, the largest matching pattern is preferred. If NAME is an array and the substitution is not quoted or the (@) flag or the `NAME[@]' syntax is used, matching is performed on each array elements separately.

${NAME:#PATTERN}
     If the PATTERN matches the value of NAME, then substitute the empty string; otherwise, just substitute the value of NAME. If NAME is an array and the substitution is not quoted or the (@) flag or the `NAME[@]' syntax is used, matching is performed on each array elements separately, and the matched array elements are removed (use the (M) flag to remove the non-matched elements).

${#SPEC}
     If SPEC is one of the above substitutions, substitute the length in characters of the result instead of the result itself.  If SPEC is an array expression, substitute the number of elements of the result.

${^SPEC}
     Turn on the RC_EXPAND_PARAM option for the evaluation of SPEC; if the `^' is doubled, turn it off. When this option is set, array expansions of the form `FOO${XX}BAR', where the parameter XX is set to (A B C), are substituted with `FOOABAR FOOBBAR FOOCBAR' instead of the default `FOOA B CBAR'.

     Internally, each such expansion is converted into the equivalent list for brace expansion.  E.g., ${^var} becomes {$var[1],$var[2],...}, and is processed as described in Brace Expansion above. If word splitting is also in effect the $var[N] may themselves be split into different list elements.

${=SPEC}
     Turn on the SH_WORD_SPLIT option for the evaluation of SPEC; if the `=' is doubled, turn it off. When this option is set, parameter values are split into separate words using IFS as a delimiter before substitution. This is done by default in most other shells.

${~SPEC}
     Turn on the GLOB_SUBST option for the evaluation of SPEC; if the `~' is doubled, turn it off.  When this option is set, any pattern characters resulting from the substitution become eligible for file expansion and filename generation.

If a ${...} type parameter expression or a $(...) type command substitution is used in place of NAME above, it is substituted first and the result is used as if it were the value of NAME.  Thus it is possible to perform nested operations:  ${${foo#head}%tail} substitues the value of $foo with both head and tail deleted.  The form with $(...) is often useful in combination with the flags described next; see the example below.

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

If the opening brace is directly followed by an opening parenthesis, the string up to the matching closing parenthesis will be taken as a list of flags.  Where arguments are valid, any character, or the matching pairs `(...)', `{...}', `[...]', or `<...>',  may be used in place of the colon as delimiters.  The following flags are supported:

A
     Create an array parameter with ${...:=...} or ${...::=...}. Assignment is made before sorting or padding.

@
     In double quotes, array elements are put into separate words. E.g., `"${(@)foo}"' is equivalent to `"${foo[@]}"' and `"${(@)foo[1,2]}"' is the same as `"$foo[1]" "$foo[2]"'.

e
     Perform parameter expansion, command substitution and arithmetic expansion on the result. Such expansions can be nested but too deep recursion may have unpredictable effects.

o
     Sort the resulting words in ascending order.

O
     Sort the resulting words in descending order.

i
     With o or O, sort case-independently.

L
     Convert all letters in the result to lower case.

U
     Convert all letters in the result to upper case.

C
     Capitalize the resulting words.

c
     With ${#NAME}, count the total number of characters in an array, as if the elements were concatenated with spaces between them.

w
     With ${#NAME}, count words in arrays or strings; the s flag may be used to set a word delimiter.

W
     Similar to w with the difference that empty words between repeated delimiters are also counted.

p
     Recognize the same escape sequences as the print builtin in string arguments to subsequent flags.

l:EXPR::STRING1::STRING2:
     Pad the resulting words on the left.  Each word will be truncated if required and placed in a field EXPR characters wide.  The space to the left will be filled with STRING1 (concatenated as often as needed) or spaces if STRING1 is not given.  If both STRING1 and STRING2 are given, this string will be placed exactly once directly to the left of the resulting word.

r:EXPR::STRING1::STRING2:
     As l, but pad the words on the right.

j:STRING:
     Join the words of arrays together using STRING as a separator. Note that this occurs before field splitting by the SH_WORD_SPLIT option.

F
     Join the words of arrays together using newline as a separator. This is a shorthand for `pj:\n:'.

s:STRING:
     Force field splitting (see the option SH_WORD_SPLIT) at the separator STRING.  Splitting only occurs in places where an array value is valid.

f
     Split the result of the expansion to lines. This is a shorthand for `ps:\n:'.

S
     (This and all remaining flags are used with the ${...#...} or ${...%...} forms.) Search substrings as well as beginnings or ends.

I:EXPR:
     Search the EXPRth match (where EXPR evaluates to a number).

M
     Include the matched portion in the result.

R
     Include the unmatched portion in the result (the Rest).

B
     Include the index of the beginning of the match in the result.

E
     Include the index of the end of the match in the result.

N
     Include the length of the match in the result.

Example
-------

The flag f is useful to split a double-quoted substitution line by line.  For example, `"${(f)$(<FILE)}"' will substitue the contents of FILE divided so that one line is supplied per argument to CMD.  Compare this with the effect of `$(<FILE)' alone, which divides the file up by words, or the same inside double quotes, where the entire contents of the file are passed as a single argument.

Command Substitution
====================

A command enclosed in parentheses preceded by a dollar sign, like `$(...)', or quoted with grave accents, like ``...`', is replaced with its standard output, with any trailing newlines deleted. If the substitution is not enclosed in double quotes, the output is broken into words using the IFS parameter. The substitution `$(cat FOO)' may be replaced by the equivalent but faster `$(<FOO)'. In either case, if the option GLOB_SUBST is set, the output is eligible for filename generation.

Arithmetic Expansion
====================

A string of the form `$[EXP]' or `$((EXP))' is substituted with the value of the arithmetic expression EXP.  EXP is subjected to parameter expansion, command substitution and arithmetic expansion before it is evaluated. See Arithmetic Evaluation.

Brace Expansion
===============

A string of the form `FOO{XX,YY,ZZ}BAR' is expanded to the individual words `FOOXXBAR', `FOOYYBAR' and `FOOZZBAR'. Left-to-right order is preserved.  This construct may be nested.  Commas may be quoted in order to include them literally in a word.

An expression of the form `{N1..N2}', where N1 and N2 are integers, is expanded to every number between N1 and N2 inclusive.  If either number begins with a zero, all the resulting numbers will be padded with leading zeroes to that minimum width.  If the numbers are in decreasing order the resulting sequence will also be in decreasing order.

If a brace expression matches none of the above forms, it is left unchanged, unless the BRACE_CCL option is set. In that case, it is expanded to a sorted list of the individual characters between the braces, in the manner of a search set. `-' is treated specially as in a search set, but `^' or `!' as the first character is treated normally.

Filename Expansion
==================

Each word is checked to see if it begins with an unquoted `~'. If it does, then the word up to a `/', or the end of the word if there is no `/', is checked to see if it can be substituted in one of the ways described here.  If so, then the `~' and the checked portion are replaced with the appropriate substitute value.

A `~' by itself is replaced by the value of $HOME. A `~' followed by a `+' or a `-' is replaced by the value of $PWD or $OLDPWD, respectively.

A `~' followed by a number is replaced by the directory at that position in the directory stack. `~0' is equivalent to `~+', and `~1' is the top of the stack. `~+' followed by a number is replaced by the directory at that position in the directory stack. `~+0' is equivalent to `~+', and `~+1' is the top of the stack. `~-' followed by a number is replaced by the directory that many positions from the bottom of the stack. `~-0' is the bottom of the stack. The PUSHD_MINUS option exchanges the effects of `~+' and `~-' where they are followed by a number.

A `~' followed by anything not already covered is looked up as a named directory, and replaced by the value of that named directory if found. Named directories are typically home directories for users on the system. They may also be defined if the text after the `~' is the name of a string shell parameter whose value begins with a `/'. It is also possible to define directory names using the -d option to the hash builtin.

In certain circumstances (in prompts, for instance), when the shell prints a path, the path is checked to see if it has a named directory as its prefix.  If so, then the prefix portion is replaced with a `~' followed by the name of the directory. The shortest way of referring to the directory is used, with ties broken in favour of using a named directory, except when the directory is / itself.

If a word begins with an unquoted `=' and the EQUALS option is set, the remainder of the word is taken as the name of a command or alias.  If a command exists by that name, the word is replaced by the full pathname of the command. If an alias exists by that name, the word is replaced with the text of the alias.

Filename expansion is performed on the right hand side of a parameter assignment, including those appearing after commands of the typeset family.  In this case, the right hand side will be treated as a colon-separated list in the manner of the PATH parameter, so that a `~' or an `=' following a `:' is eligible for expansion. All such behaviour can be disabled by quoting the `~', the `=', or the whole expression (but not simply the colon); the EQUALS option is also respected.

If the option MAGIC_EQUAL_SUBST is set, any unquoted shell argument in the form `IDENTIFIER=EXPRESSION' becomes eligible for file expansion as described in the previous paragraph.  Quoting the first `=' also inhibits this.

Filename Generation
===================

If a word contains an unquoted instance of one of the characters `*', `(', `|', `<', `[', or `?', it is regarded as a pattern for filename generation, unless the GLOB option is unset. If the EXTENDED_GLOB option is set, the `^' and `#' characters also denote a pattern; otherwise they are not treated specially by the shell.

The word is replaced with a list of sorted filenames that match the pattern.  If no matching pattern is found, the shell gives an error message, unless the NULL_GLOB option is set, in which case the word is deleted; or unless the NOMATCH option is unset, in which case the word is left unchanged.

In filename generation, the character `/' must be matched explicitly; also, a `.' must be matched explicitly at the beginning of a pattern or after a `/', unless the GLOB_DOTS option is set. No filename generation pattern matches the files `.' or `..'.  In other instances of pattern matching, the `/' and `.' are not treated specially.

Glob Operators
--------------

*
     Matches any string, including the null string.

?
     Matches any character.

[...]
     Matches any of the enclosed characters.  Ranges of characters can be specified by separating two characters by a `-'. A `-' or `]' may be matched by including it as the first character in the list. There are also several named classes of characters, in the form `[:NAME(+tt:])' with the following meanings:  `[:alnum:]' alphanumeric, `[:alpha:]' alphabetic, `[:blank:]' space or tab, `[:cntrl:]' control character, `[:digit:]' decimal digit, `[:graph:]' printable character except whitespace, `[:lower:]' lowercase letter, `[:print:]' printable character, `[:punct:]' printable character neither alphanumeric nor whitespace, `[:space:]' whitespace character, `[:upper:]' uppercase letter, `[:xdigit:]' hexadecimal digit.  These use the macros provided by the operating system to test for the given character combinations, including any modifications due to local language settings:  see man page ctype(3).  Note that the square brackets are additional to those enclosing the whole set of characters, so to test for a single alphanumeric character you need `[[:alnum:]]'.  Named character sets can be used alongside other types, e.g. `[[:alpha:]0-9]'.

[^...]
[!...]
     Like [...], except that it matches any character which is not in the given set.

<[X]-[Y]>
     Matches any number in the range X to Y, inclusive. Either of the numbers may be omitted to make the range open-ended; hence `<->' matches any number.

(...)
     Matches the enclosed pattern.  This is used for grouping. If the KSH_GLOB option is set, then a `@', `*', `+', `?' or `!' immediately preceding the `(' is treated specially, as detailed below.

X|Y
     Matches either X or Y. This operator has lower precedence than any other. The `|' character must be within parentheses, to avoid interpretation as a pipeline.

^X
     (Requires EXTENDED_GLOB to be set.) Matches anything except the pattern X. This has a higher precedence than `/', so `^foo/bar' will search directories in `.' except `./foo' for a file named `bar'.

X~Y
     (Requires EXTENDED_GLOB to be set.) Match anything that matches the pattern X but does not match Y. This has lower precedence than any operator except `|', so `*/*~foo/bar' will search for all files in all directories in `.' and then exclude `foo/bar' if there was such a match. It groups left-to-right, so multiple patterns can be excluded by `FOO~BAR~BAZ'. In the exclusion pattern (Y), `/' and `.' are not treated specially the way they usually are in globbing.

X#
     (Requires EXTENDED_GLOB to be set.) Matches zero or more occurrences of the pattern X. This operator has high precedence; `12#' is equivalent to `1(2#)', rather than `(12)#'.

X##
     (Requires EXTENDED_GLOB to be set.) Matches one or more occurrences of the pattern X. This operator has high precedence; `12##' is equivalent to `1(2##)', rather than `(12)##'.

ksh-like Glob Operators
-----------------------

If the KSH_GLOB option is set, the effects of parentheses can be modified by a preceding `@', `*', `+', `?' or `!'. This character need not be unquoted to have special effects, but the `(' must be.

@(...)
     Match the pattern in the parentheses.  (Like `(...)'.)

*(...)
     Match any number of occurrences.  (Like `(...)#'.)

+(...)
     Match at least one occurrence.  (Like `(...)##'.)

?(...)
     Match zero or one occurrence.  (Like `(|...)'.)

!(...)
     Match anything but the expression in parentheses. (Like `(^(...))'.)

Recursive Globbing
------------------

A pathname component of the form `(FOO/)#' matches a path consisting of zero or more directories matching the pattern FOO. As a shorthand, `**/' is equivalent to `(*/)#'. Thus:

ls (*/)#bar

or

ls **/bar

does a recursive directory search for files named `bar', not following symbolic links.  To follow links, use `***/'.

Glob Qualifiers
---------------

Patterns used for filename generation may end in a list of qualifiers enclosed in parentheses. The qualifiers specify which filenames that otherwise match the given pattern will be inserted in the argument list.

If the option BARE_GLOB_QUAL is set, then a trailing set of parentheses containing no `|' or `(' characters (or `~' if it is special) is taken as a set of glob qualifiers.  A glob subexpression that would normally be taken as glob qualifiers, for example `(^x)', can be forced to be treated as part of the glob pattern by doubling the parentheses, for example `((^x))'.

A qualifier may be any one of the following:

/
     directories

.
     plain files

@
     symbolic links

=
     sockets

p
     named pipes (FIFOs)

*
     executable plain files (0100)

%
     device files (character or block special)

%b
     block special files

%c
     character special files

r
     owner-readable files (0400)

w
     owner-writable files (0200)

x
     owner-executable files (0100)

A
     group-readable files (0040)

I
     group-writable files (0020)

E
     group-executable files (0010)

R
     world-readable files (0004)

W
     world-writable files (0002)

X
     world-executable files (0001)

s
     setuid files (04000)

S
     setgid files (02000)

t
     files with the sticky bit (01000)

dDEV
     files on the device DEV

l[-|+]CT
     files having a link count less than CT (-), greater than CT (+), or is equal to CT

U
     files owned by the effective user ID

G
     files owned by the effective group ID

uID
     files owned by user ID ID if it is a number, if not, than the character after the `u' will be used as a separator and the string between it and the next matching separator (`(', `[', `{', and `<' match `)', `]', `}', and `>' respectively, any other character matches itself) will be taken as a user name, and the user ID of this user will be taken (e.g. `u:foo:' or `u[foo]' for user `foo')

gID
     like uID but with group IDs or names

a[Mwhm][-|+]N
     files accessed exactly N days ago.  Files accessed within the last N days are selected using a negative value for N (-N).  Files accessed more than N days ago are selected by a positive N value (+N).  Optional unit specifiers `M', `w', `h' or `m' (e.g. `ah5') cause the check to be performed with months (of 30 days), weeks, hours, or minutes instead of days, respectively.  For instance, `echo *(ah-5)' would echo files accessed within the last five hours.

m[Mwhm][-|+]N
     like the file access qualifier, except that it uses the file modification time.

c[Mwhm][-|+]N
     like the file access qualifier, except that it uses the file inode change time.

L[+|-]N
     files less than N bytes (-), more than N bytes (+), or exactly N bytes in length. If this flag is directly followed by a `k' (`K'), `m' (`M'), or `p' (`P') (e.g. `Lk-50') the check is performed with kilobytes, megabytes, or blocks (of 512 bytes) instead.

^
     negates all qualifiers following it

-
     toggles between making the qualifiers work on symbolic links (the default) and the files they point to

M
     sets the MARK_DIRS option for the current pattern

T
     appends a trailing qualifier mark to the file names, analogous to the LIST_TYPES option, for the current pattern (overrides M)

N
     sets the NULL_GLOB option for the current pattern

D
     sets the GLOB_DOTS option for the current pattern

More than one of these lists can be combined, separated by commas. The whole list matches if at least one of the sublists matches (they are `or'ed, the qualifiers in the sublists are `and'ed).

If a `:' appears in a qualifier list, the remainder of the expression in parenthesis is interpreted as a modifier (see Modifiers in History Expansion).  Note that each modifier must be introduced by a separate `:'.  Note also that the result after modification does not have to be an existing file.  The name of any existing file can be followed by a modifier of the form `(:..)' even if no actual filename generation is performed. Thus:

ls *(-/)

lists all directories and symbolic links that point to directories, and

ls *(%W)

lists all world-writable device files in the current directory, and

ls *(W,X)

lists all files in the current directory that are world-writable or world-executable, and

echo /tmp/foo*(u0^@:t)

outputs the basename of all root-owned files beginning with the string `foo' in /tmp, ignoring symlinks, and

ls *.*~(lex|parse).[ch](^D^l1)

lists all files having a link count of one whose names contain a dot (but not those starting with a dot, since GLOB_DOTS is explicitly switched off) except for lex.c, lex.h, parse.c and parse.h.

Parameters
**********

Description
===========

A parameter has a name, a value, and a number of attributes. A name may be any sequence of alphanumeric characters and underscores, or the single characters `*', `@', `#', `?', `-', `$', or `!'. The value may be a scalar (a string), an integer, or an array. To assign a scalar or integer value to a parameter, use the typeset builtin. To assign an array value, use `set -A NAME VALUE ...'. The value of a parameter may also be assigned by writing:

NAME=VALUE

If the integer attribute, -i, is set for NAME, the VALUE is subject to arithmetic evaluation.

In the parameter lists, the mark `<S>' indicates that the parameter is special. Special parameters cannot have their type changed, and they stay special even if unset.  `<Z>' indicates that the parameter does not exist when the shell initialises in sh or ksh emulation mode.

Local Parameters
================

Shell function executions delimit scopes for shell parameters. (Parameters are dynamically scoped.)  The typeset builtin, and its alternative forms declare, integer, local and readonly (but not export), can be used to declare a parameter as being local to the innermost scope.

When a parameter is read or assigned to, the innermost existing parameter of that name is used.  (That is, the local parameter hides any less-local parameter.)  However, assigning to a non-existent parameter, or declaring a new parameter with export, causes it to be created in the outermost scope.

Local parameters disappear when their scope ends. unset can be used to delete a parameter while it is still in scope; this will reveal the next outer parameter of the same name.  However, special parameters are still special when unset.

Array Parameters
================

The value of an array parameter may be assigned by writing:

NAME=(VALUE ...)

Individual elements of an array may be selected using a subscript.  A subscript of the form `[EXP]' selects the single element EXP, where EXP is an arithmetic expression which will be subject to arithmetic expansion as if it were surrounded by `$((...))'. The elements are numbered beginning with 1 unless the KSH_ARRAYS option is set when they are numbered from zero.

A subscript of the form `[*]' or `[@]' evaluates to all elements of an array; there is no difference between the two except when they appear within double quotes. `"$foo[*]"' evaluates to `"$foo[1] $foo[2] ..."', while `"$foo[@]"' evaluates to `"$foo[1]" "$foo[2]"', etc.

A subscript of the form `[EXP1,EXP2]' selects all elements in the range EXP1 to EXP2, inclusive. If one of the subscripts evaluates to a negative number, say -N, then the Nth element from the end of the array is used.  Thus `$foo[-3]' is the third element from the end of the array foo, and `$foo[1,-1]' is the same as `$foo[*]'.

Subscripting may also be performed on non-array values, in which case the subscripts specify a substring to be extracted. For example, if FOO is set to `foobar', then `echo $FOO[2,5]' prints `ooba'.

Subscripts may be used inside braces used to delimit a parameter name, thus `${foo[2]}' is equivalent to `$foo[2]'.  If the KSH_ARRAYS option is set, the braced form is the only one that will work, the subscript otherwise not being treated specially.

If a subscript is used on the left side of an assignment the selected range is replaced by the expression on the right side.

If the opening bracket or the comma is directly followed by an opening parentheses the string up to the matching closing one is considered to be a list of flags. The flags currently understood are:

e
     this option has no effect and retained for backward compatibility only.

w
     if the parameter subscripted is a scalar than this flag makes subscription work on a per-word basis instead of characters.

s:STRING:
     this gives the STRING that separates words (for use with the w flag).

p
     Recognize the same escape sequences as the print builtin in the string argument of a subsequent `s' flag.

f
     if the parameter subscripted is a scalar than this flag makes subscription work on a per-line basis instead of characters. This is a shorthand for `pws:\n:'.

r
     if this flag is given the EXP is taken as a pattern and the result is the first matching array element, substring or word (if the parameter is an array, if it is a scalar, or if it is a scalar and the `w' flag is given, respectively); note that this is like giving a number: `$foo[(r)??,3]' and `$foo[(r)??,(r)f*]' work.

R
     like `r', but gives the last match.

i
     like `r', but gives the index of the match instead; this may not be combined with a second argument.

I
     like `i, but gives the index of the last match.

n:EXPR:
     if combined with `r', `R', `i' or `I', makes them give the Nth or Nth last match (if EXPR evaluates to N).

Positional Parameters
=====================

Positional parameters are set by the shell on invocation, by the set builtin, or by direct assignment. The parameter N, where N is a number, is the Nth positional parameter. The parameters *, @ and argv are arrays containing all the positional parameters; thus `$argv[N]', etc., is equivalent to simply `$N'.

Parameters Set By The Shell
===========================

The following parameters are automatically set by the shell:

! <S>
     The process ID of the last background command invoked.

# <S>
     The number of positional parameters in decimal.

ARGC <S> <Z>
     Same as #.

$ <S>
     The process ID of this shell.

- <S>
     Flags supplied to the shell on invocation or by the set or setopt commands.

* <S>
     An array containing the positional parameters.

argv <S> <Z>
     Same as *.

@ <S>
     Same as argv[@].

? <S>
     The exit value returned by the last command.

0 <S>
     The name used to invoke the current shell.  If the FUNCTION_ARGZERO option is set, this is set temporarily within a shell function to the name of the function, and within a sourced script to the name of the script.

status <S> <Z>
     Same as ?.

_ <S>
     The last argument of the previous command. Also, this parameter is set in the environment of every command executed to the full pathname of the command.

EGID <S>
     The effective group ID of the shell process.  If you have sufficient privileges, you may change the effective group ID of the shell process by assigning to this parameter.  Also (assuming sufficient privileges), you may start a single command with a different effective group ID by `(EGID=GID; command)'

EUID <S>
     The effective user ID of the shell process.  If you have sufficient privileges, you may change the effective user ID of the shell process by assigning to this parameter.  Also (assuming sufficient privileges), you may start a single command with a different effective user ID by `(EUID=UID; command)'

ERRNO <S>
     The value of errno (see man page errno(3)) as set by the most recently failed system call. This value is system dependent and is intended for debugging purposes.

GID <S>
     The real group ID of the shell process.  If you have sufficient privileges, you may change the group ID of the shell process by assigning to this parameter.  Also (assuming sufficient privileges), you may start a single command under a different group ID by `(GID=GID; command)'

HOST
     The current hostname.

LINENO <S>
     The line number of the current line within the current script being executed.

LOGNAME
     If the corresponding variable is not set in the environment of the shell, it is initialized to the login name corresponding to the current login session. This parameter is exported by default but this can be disabled using the typeset builtin.

MACHTYPE
     The machine type (microprocessor class or machine model), as determined at compile time.

OLDPWD
     The previous working directory.  This is set when the shell initialises and whenever the directory changes.

OPTARG <S>
     The value of the last option argument processed by the getopts command.

OPTIND <S>
     The index of the last option argument processed by the getopts command.

OSTYPE
     The operating system, as determined at compile time.

PPID <S>
     The process ID of the parent of the shell.

PWD
     The present working directory.  This is set when the shell initialises and whenever the directory changes.

RANDOM <S>
     A random integer from 0 to 32767, newly generated each time this parameter is referenced.  The random number generator can be seeded by assigning a numeric value to RANDOM.

SECONDS <S>
     The number of seconds since shell invocation.  If this parameter is assigned a value, then the value returned upon reference will be the value that was assigned plus the number of seconds since the assignment.

SHLVL <S>
     Incremented by one each time a new shell is started.

signals
     An array containing the names of the signals.

TTY
     The name of the tty associated with the shell, if any.

TTYIDLE <S>
     The idle time of the tty associated with the shell in seconds or -1 if there is no such tty.

UID <S>
     The real user ID of the shell process.  If you have sufficient privileges, you may change the user ID of the shell by assigning to this parameter. Also (assuming sufficient privileges), you may start a single command under a different user ID by `(UID=UID; command)'

USERNAME <S>
     The username corresponding to the real user ID of the shell process.  If you have sufficient privileges, you may change the username (and also the user ID and group ID) of the shell by assigning to this parameter. Also (assuming sufficient privileges), you may start a single command under a different username (and user ID and group ID) by `(USERNAME=USERNAME; command)'

VENDOR
     The vendor, as determined at compile time.

ZSH_NAME
     Expands to the basename of the command used to invoke this instance of zsh.

ZSH_VERSION
     The version number of this zsh.

Parameters Used By The Shell
============================

The following parameters are used by the shell:

ARGV0
     If exported, its value is used as argv[0] of external commands. Usually used in constructs like `ARGV0=emacs nethack'.

BAUD
     The baud rate of the current connection.  Used by the line editor update mechanism to compensate for a slow terminal by delaying updates until necessary.  This may be profitably set to a lower value in some circumstances, e.g. for slow modems dialing into a communications server which is connected to a host via a fast link; in this case, this variable would be set by default to the speed of the fast link, and not the modem. This parameter should be set to the baud rate of the slowest part of the link for best performance. The compensation mechanism can be turned off by setting the variable to zero.

cdpath <S> <Z> (CDPATH <S>)
     An array (colon-separated list) of directories specifying the search path for the cd command.

COLUMNS <S>
     The number of columns for this terminal session. Used for printing select lists and for the line editor.

DIRSTACKSIZE
     The maximum size of the directory stack.  If the stack gets larger than this, it will be truncated automatically. This is useful with the AUTO_PUSHD option.

FCEDIT
     The default editor for the fc builtin.

fignore <S> <Z> (FIGNORE <S>)
     An array (colon separated list) containing the suffixes of files to be ignored during filename completion.  However, if the completion generates only files which would match if this variable would be ignored, than these files are completed anyway.

fpath <S> <Z> (FPATH <S>)
     An array (colon separated list) of directories specifying the search path for function definitions.  This path is searched when a function with the -u attribute is referenced.  If an executable file is found, then it is read and executed in the current environment.

histchars <S>
     Three characters used by the shell's history and lexical analysis mechanism.  The first character signals the start of a history substitution (default `!').  The second character signals the start of a quick history substitution (default `^').  The third character is the comment character (default `#').

HISTCHARS <S> <Z>
     Same as histchars.  (Deprecated.)

HISTFILE
     The file to save the history in when an interactive shell exits. If unset, the history is not saved.

HISTSIZE <S>
     The maximum size of the history list.

HOME <S>
     The default argument for the cd command.

IFS <S>
     Internal field separators (by default space, tab, newline and NUL), that are used to separate words which result from command or parameter substitution and words read by the read builtin.  Any characters from the set space, tab and newline that appear in the IFS are called IFS white space. One or more IFS white space characters or one non-IFS white space character together with any adjacent IFS white space character delimit a field.  If an IFS white space character appears twice consecutively in the IFS, this character is treated as if it were not an IFS white space character.

KEYTIMEOUT
     The time the shell waits, in hundredths of seconds, for another key to be pressed when reading bound multi-character sequences.

LANG <S>
     This variable determines the locale category for any category not specifically selected via a variable starting with `LC_'.

LC_ALL <S>
     This variable overrides the value of the `LANG' variable and the value of any of the other variables starting with `LC_'.

LC_COLLATE <S>
     This variable determines the locale category for character collation information within ranges in glob brackets and for sorting.

LC_CTYPE <S>
     This variable determines the locale category for character handling functions.

LC_MESSAGES <S>
     This variable determines the language in which messages should be written.  Note that zsh does not use message catalogs.

LC_TIME <S>
     This variable determines the locale category for date and time formatting in prompt escape sequences.

LINES <S>
     The number of lines for this terminal session. Used for printing select lists and for the line editor.

LISTMAX
     In the line editor, the number of filenames to list without asking first. If set to zero, the shell asks only if the top of the listing would scroll off the screen.

LOGCHECK
     The interval in seconds between checks for login/logout activity using the watch parameter.

MAIL
     If this parameter is set and mailpath is not set, the shell looks for mail in the specified file.

MAILCHECK
     The interval in seconds between checks for new mail.

mailpath <S> <Z> (MAILPATH <S>)
     An array (colon-separated list) of filenames to check for new mail.  Each filename can be followed by a `?' and a message that will be printed.  The message will undergo parameter expansion, command substitution and arithmetic substitution with the variable $_ defined as the name of the file that has changed.  The default message is `You have new mail'.  If an element is a directory instead of a file the shell will recursively check every file in every subdirectory of the element.

manpath <S> <Z> (MANPATH <S> <Z>)
     An array (colon-separated list) whose value is not used by the shell.  The manpath array can be useful, however, since setting it also sets MANPATH, and vice versa.

module_path <S> <Z> (MODULE_PATH <S>)
     An array (colon-separated list) of directories that zmodload searches for dynamically loadable modules. This is initialised to a standard pathname, usually `/usr/local/lib/zsh/$ZSH_VERSION'. (The `/usr/local/lib' part varies from installation to installation.) For security reasons, any value set in the environment when the shell is started will be ignored.

     These parameters only exist if the installation supports dynamic module loading.

NULLCMD <S>
     The command name to assume if a redirection is specified with no command.  Defaults to cat.  For sh/ksh behavior, change this to :.  For csh-like behavior, unset this parameter; the shell will print an error message if null commands are entered.

path <S> <Z> (PATH <S>)
     An array (colon-separated list) of directories to search for commands. When this parameter is set, each directory is scanned and all files found are put in a hash table.

POSTEDIT <S>
     This string is output whenever the line editor exits. It usually contains termcap strings to reset the terminal.

PS1 <S>
     The primary prompt string, printed before a command is read. the default is `%m%# '.  It undergoes a special form of expansion before being displayed; see Prompt Expansion.

PS2 <S>
     The secondary prompt, printed when the shell needs more information to complete a command. It is expanded in the same way as PS1. The default is `%_> ', which displays any shell constructs or quotation marks which are currently being processed.

PS3 <S>
     Selection prompt used within a select loop. It is expanded in the same way as PS1. The default is `?# '.

PS4 <S>
     The execution trace prompt.  Default is `+ '.

PROMPT <S> <Z>
PROMPT2 <S> <Z>
PROMPT3 <S> <Z>
PROMPT4 <S> <Z>
     Same as PS1, PS2, PS3 and PS4, respectively.

psvar <S> <Z> (PSVAR <S>)
     An array (colon-separated list) whose first nine values can be used in PROMPT strings.  Setting psvar also sets PSVAR, and vice versa.

prompt <S> <Z>
     Same as PS1.

READNULLCMD <S>
     The command name to assume if a single input redirection is specified with no command.  Defaults to more.

REPORTTIME
     If nonnegative, commands whose combined user and system execution times (measured in seconds) are greater than this value have timing statistics printed for them.

RPROMPT <S>
RPS1 <S>
     This prompt is displayed on the right-hand side of the screen when the primary prompt is being displayed on the left. This does not work if the SINGLELINEZLE option is set. It is expanded in the same way as PS1.

SAVEHIST
     The maximum number of history events to save in the history file.

SPROMPT <S>
     The prompt used for spelling correction.  The sequence `%R' expands to the string which presumably needs spelling correction, and `%r' expands to the proposed correction. All other prompt escapes are also allowed.

STTY
     If this parameter is set in a command's environment, the shell runs the stty command with the value of this parameter as arguments in order to set up the terminal before executing the command. The modes apply only to the command, and are reset when it finishes or is suspended. If the command is suspended and continued later with the fg or wait builtins it will see the modes specified by STTY, as if it were not suspended.  This (intentionally) does not apply if the command is continued via `kill -CONT'. STTY is ignored if the command is run in the background, or if it is in the environment of the shell but not explicitly assigned to in the input line. This avoids running stty at every external command by accidentally exporting it. Also note that STTY should not be used for window size specifications; these will not be local to the command.

TERM <S>
     The type of terminal in use.  This is used when looking up termcap sequences.

TIMEFMT
     The format of process time reports with the time keyword. The default is `%E real  %U user  %S system  %P %J'. Recognizes the following escape sequences:

     %%
          A `%'.

     %U
          CPU seconds spent in user mode.

     %S
          CPU seconds spent in kernel mode.

     %E
          Elapsed time in seconds.

     %P
          The CPU percentage, computed as (%U+%S)/%E.

     %J
          The name of this job.

     A star may be inserted between the percent sign and flags printing time. This cause the time to be printed in `HH:MM:SS.TTT' format (hours and minutes are only printed if they are not zero).

TMOUT
     If this parameter is nonzero, the shell will receive an ALRM signal if a command is not entered within the specified number of seconds after issuing a prompt. If there is a trap on SIGALRM, it will be executed and a new alarm is scheduled using the value of the TMOUT parameter after executing the trap.  If no trap is set, and the idle time of the terminal is not less than the value of the TMOUT parameter, zsh terminates.  Otherwise a new alarm is scheduled to TMOUT seconds after the last keypress.

TMPPREFIX
     A pathname prefix which the shell will use for all temporary files. Note that this should include an initial part for the file name as well as any directory names.  The default is `/tmp/zsh'.

watch <S> <Z> (WATCH <S>)
     An array (colon-separated list) of login/logout events to report. If it contains the single word `all', then all login/logout events are reported.  If it contains the single word `notme', then all events are reported as with `all' except $USERNAME. An entry in this list may consist of a username, an `@' followed by a remote hostname, and a `%' followed by a line (tty). Any or all of these components may be present in an entry; if a login/logout event matches all of them, it is reported.

WATCHFMT
     The format of login/logout reports if the watch parameter is set. Default is `%n has %a %l from %m'. Recognizes the following escape sequences:

     %n
          The name of the user that logged in/out.

     %a
          The observed action, i.e. "logged on" or "logged off".

     %l
          The line (tty) the user is logged in on.

     %M
          The full hostname of the remote host.

     %m
          The hostname up to the first `.'.  If only the IP address is available or the utmp field contains the name of an X-windows display, the whole name is printed.

          NOTE: The `%m' and `%M' escapes will work only if there is a host name field in the utmp on your machine.  Otherwise they are treated as ordinary strings.

     %S (%s)
          Start (stop) standout mode.

     %U (%u)
          Start (stop) underline mode.

     %B (%b)
          Start (stop) boldface mode.

     %t
     %@
          The time, in 12-hour, am/pm format.

     %T
          The time, in 24-hour format.

     %w
          The date in `DAY-DD' format.

     %W
          The date in `MM/DD/YY' format.

     %D
          The date in `YY-MM-DD' format.

     %(X:TRUE-TEXT:FALSE-TEXT)
          Specifies a ternary expression. The character following the X is arbitrary; the same character is used to separate the text for the "true" result from that for the "false" result. Both the separator and the right parenthesis may be escaped with a backslash. Ternary expressions may be nested.

          The test character X may be any one of `l', `n', `m' or `M', which indicate a `true' result if the corresponding escape sequence would return a non-empty value; or it may be `a', which indicates a `true' result if the watched user has logged in, or `false' if he has logged out. Other characters evaluate to neither true nor false; the entire expression is omitted in this case.

          If the result is `true', then the TRUE-TEXT is formatted according to the rules above and printed, and the FALSE-TEXT is skipped. If `false', the TRUE-TEXT is skipped and the FALSE-TEXT is formatted and printed. Either or both of the branches may be empty, but both separators must be present in any case.

WORDCHARS <S>
     A list of non-alphanumeric characters considered part of a word by the line editor.

ZDOTDIR
     The directory to search for shell startup files (.zshrc, etc), if not $HOME.

Options
*******

Specifying Options
==================

Options are primarily referred to by name. These names are case insensitive and underscores are ignored. For example, `allexport' is equivalent to `A__lleXP_ort'.

The sense of an option name may be inverted by preceding it with `no', so `setopt No_Beep' is equivalent to `unsetopt beep'. This inversion can only be done once, so `nonobeep' is not a synonym for `beep'.  Similarly, `tify' is not a synonym for `nonotify' (the inversion of `notify').

Some options also have one or more single letter names. There are two sets of single letter options: one used by default, and another used to emulate sh/ksh (used when the SH_OPTION_LETTERS option is set). The single letter options can be used on the shell command line, or with the set, setopt and unsetopt builtins, as normal Unix options preceded by `-'.

The sense of the single letter options may be inverted by using `+' instead of `-'. Some of the single letter option names refer to an option being off, in which case the inversion of that name refers to the option being on. For example, `+n' is the short name of `exec', and `-n' is the short name of its inversion, `noexec'.

Description of Options
======================

ALL_EXPORT (-a, ksh: -a)
     All parameters subsequently defined are automatically exported.

ALWAYS_LAST_PROMPT
     If unset, key functions that list completions try to return to the last prompt if given a numeric argument. If set these functions try to return to the last prompt if given no numeric argument.

ALWAYS_TO_END
     If a completion is performed with the cursor within a word, and a full completion is inserted, the cursor is moved to the end of the word.  That is, the cursor is moved to the end of the word if either a single match is inserted or menu completion is performed.

APPEND_HISTORY
     If this is set, zsh sessions will append their history list to the history file, rather than overwrite it. Thus, multiple parallel zsh sessions will all have their history lists added to the history file, in the order they are killed.

AUTO_CD (-J)
     If a command is issued that can't be executed as a normal command, and the command is the name of a directory, perform the cd command to that directory.

AUTO_LIST (-9)
     Automatically list choices on an ambiguous completion.

AUTO_MENU
     Automatically use menu completion after the second consecutive request for completion, for example by pressing the tab key repeatedly. This option is overridden by MENU_COMPLETE.

AUTO_NAME_DIRS
     Any parameter that is set to the absolute name of a directory immediately becomes a name for that directory, that will be used by the `%~' and related prompt sequences, and will be available when completion is performed on a word starting with `~'. (Otherwise, the parameter must be used in the form `~PARAM' first.)

AUTO_PARAM_KEYS
     If a parameter name was completed and a following character (normally a space) automatically inserted, and the next character typed is one of those that have to come directly after the name (like `}', `:', etc.), the automatically added character is deleted, so that the character typed comes immediately after the parameter name. Completion in a brace expansion is affected similarly: the added character is a `,', which will be removed if `}' is typed next.

AUTO_PARAM_SLASH
     If a parameter is completed whose content is the name of a directory, then add a trailing slash instead of a space.

AUTO_PUSHD (-N)
     Make cd push the old directory onto the directory stack.

AUTO_REMOVE_SLASH
     When the last character resulting from a completion is a slash and the next character typed is a word delimiter or a slash, remove the slash.

AUTO_RESUME (-W)
     Treat single word simple commands without redirection as candidates for resumption of an existing job.

BAD_PATTERN (+2)
     If a pattern for filename generation is badly formed, print an error message. (If this option is unset, the pattern will be left unchanged.)

BANG_HIST (+K)
     Perform textual history substitution, csh-style, treating the character `!' specially.

BARE_GLOB_QUAL
     In a glob pattern, treat a trailing set of parentheses as a qualifier list, if it contains no `|', `(' or (if special) `~' characters.  See Filename Generation.

BEEP (+B)
     Beep on error in ZLE.

BG_NICE (-6)
     Run all background jobs at a lower priority.  This option is set by default.

BRACE_CCL
     Expand expressions in braces which would not otherwise undergo brace expansion to a lexically ordered list of all the characters.  See Brace Expansion.

BSD_ECHO
     Make the echo builtin compatible with the BSD man page echo(1) command. This disables backslashed escape sequences in echo strings unless the -e option is specified.

CDABLE_VARS (-T)
     If the argument to a cd command (or an implied cd with the AUTO_CD option set) is not a directory, and does not begin with a slash, try to expand the expression as if it were preceded by a `~' (see Filename Expansion).

CHASE_LINKS (-w)
     Resolve symbolic links to their true values when changing directory.

CLOBBER (+C, ksh: +C)
     Allows `>' redirection to truncate existing files, and `>>' to create files. Otherwise `>!' or `>|' must be used to truncate a file, and `>>!' or `>>|' to create a file.

COMPLETE_ALIASES
     Prevents aliases on the command line from being internally substituted before completion is attempted.  The effect is to make the alias a distinct command for completion purposes.

COMPLETE_IN_WORD
     If unset, the cursor is set to the end of the word if completion is started. Otherwise it stays there and completion is done from both ends.

CORRECT (-0)
     Try to correct the spelling of commands.

CORRECT_ALL (-O)
     Try to correct the spelling of all arguments in a line.

CSH_JUNKIE_HISTORY
     A history reference without an event specifier will always refer to the previous command.  Without this option, such a history reference refers to the same event as the previous history reference, defaulting to the previous command.

CSH_JUNKIE_LOOPS
     Allow loop bodies to take the form `LIST; end' instead of `do LIST; done'.

CSH_JUNKIE_QUOTES
     Changes the rules for single- and double-quoted text to match that of csh.  These require that embedded newlines be preceded by a backslash; unescaped newlines will cause an error message. In double-quoted strings, it is made impossible to escape `$', ``' or `"' (and `\' itself no longer needs escaping). Command substitutions are only expanded once, and cannot be nested.

CSH_NULL_GLOB
     If a pattern for filename generation has no matches, delete the pattern from the argument list; do not report an error unless all the patterns in a command have no matches. Overrides NULL_GLOB.

EQUALS
     Perform = filename substitution. (See Filename Expansion.)

ERR_EXIT (-e, ksh: -e)
     If a command has a non-zero exit status, execute the ZERR trap, if set, and exit.  This is disabled while running initialization scripts.

EXEC (+n, ksh: +n)
     Do execute commands.  Without this option, commands are read and checked for syntax errors, but not executed.

EXTENDED_GLOB
     Treat the `#', `~' and `^' characters as part of patterns for filename generation, etc.  (An initial unquoted `~' always produces named directory expansion.)

EXTENDED_HISTORY
     Save beginning and ending timestamps to the history file. The format of these timestamps is `:<BEGINNING TIME>:<ENDING TIME>:<COMMAND>'.

FLOW_CONTROL
     If this option is unset, output flow control via start/stop characters (usually assigned to ^S/^Q) is disabled in the shell's editor.

FUNCTION_ARGZERO
     When executing a shell function or sourcing a script, set $0 temporarily to the name of the function/script.

GLOB (+F, ksh: +f)
     Perform filename generation (globbing). (See Filename Generation.)

GLOB_ASSIGN
     If this option is set, filename generation (globbing) is performed on the right hand side of scalar parameter assignments of the form `NAME=PATTERN (e.g. `foo=*'). If the result has more than one word the parameter will become an array with those words as arguments. This option is provided for backwards compatibility only: globbing is always performed on the right hand side of array assignments of the form `NAME=(VALUE)' (e.g. `foo=(*)') and this form is recommended for clarity; with this option set, it is not possible to predict whether the result will be an array or a scalar.

GLOB_COMPLETE
     When the current word has a glob pattern, do not insert all the words resulting from the expansion but cycle through them like MENU_COMPLETE. If no matches are found, a `*' is added to the end of the word or inserted at the cursor if COMPLETE_IN_WORD is set, and expansion is attempted again.  Using patterns works not only for files but for all completions, such as options, user names, etc.

GLOB_DOTS (-4)
     Do not require a leading `.' in a filename to be matched explicitly.

GLOB_SUBST
     Treat any characters resulting from parameter substitution as being eligible for file expansion and filename generation, and any characters resulting from command substitution as being eligible for filename generation.

HASH_CMDS
     Note the location of each command the first time it is executed. Subsequent invocations of the same command will use the saved location, avoiding a path search. If this option is unset, no path hashing will be done at all.

HASH_DIRS
     Whenever a command is executed, hash the directory containing it, as well as all directories that occur earlier in the path. Has no effect if HASH_CMDS is unset.

HASH_LIST_ALL
     Whenever a command completion is attempted, make sure the entire command path is hashed first.  This makes the first completion slower.

HIST_ALLOW_CLOBBER
     Add `|' to output redirections in the history.  This allows history references to clobber files even when CLOBBER is unset.

HIST_BEEP
     Beep when an attempt is made to access a history entry which isn't there.

HIST_IGNORE_DUPS (-h)
     Do not enter command lines into the history list if they are duplicates of the previous event.

HIST_IGNORE_SPACE (-g)
     Do not enter command lines into the history list if any command on the line begins with a blank.

HIST_NO_FUNCTIONS
     Do not store function definitions in the history list.

HIST_NO_STORE
     Remove the history (fc -l) command from the history when invoked.

HIST_REDUCE_BLANKS
     Remove superfluous blanks from each command line being added to the history list.

HIST_VERIFY
     Whenever the user enters a line with history substitution, don't execute the line directly; instead, perform history substitution and reload the line into the editing buffer.

HUP
     Send the HUP signal to running jobs when the shell exits.

IGNORE_BRACES (-I)
     Do not perform brace expansion.

IGNORE_EOF (-7)
     Do not exit on end-of-file.  Require the use of exit or logout instead. However, ten consecutive EOFs will cause the shell to exit anyway, to avoid the shell hanging if its tty goes away.

INTERACTIVE (-i, ksh: -i)
     This is an interactive shell.  This option is set upon initialisation if the standard input is a tty and commands are being read from standard input. (See the discussion of SHIN_STDIN.) This heuristic may be overridden by specifying a state for this option on the command line. The value of this option cannot be changed anywhere other than the command line.

INTERACTIVE_COMMENTS (-k)
     Allow comments even in interactive shells.

KSH_ARRAYS
     Emulate ksh array handling as closely as possible.  If this option is set, array elements are numbered from zero, an array parameter without subscript refers to the first element instead of the whole array, and braces are required to delimit a subscript (`${path[2]}' rather than just `$path[2]').

KSH_AUTOLOAD
     Emulate ksh function autoloading.  This means that when a function is autoloaded, the corresponding file is merely executed, and must define the function itself.  (By default, the function is defined to the contents of the file.  However, the most common ksh-style case - of the file containing only a simple definition of the function - is always handled in the ksh-compatible manner.)

KSH_GLOB
     In pattern matching, the interpretation of parentheses is affected by a preceding `@', `*', `+', `?' or `!'. See Filename Generation.

KSH_OPTION_PRINT
     Alters the way options settings are printed.

LIST_AMBIGUOUS
     If this option is set, completions are shown only if the completions don't have a unambiguous prefix or suffix that could be inserted in the command line.

LIST_BEEP
     Beep on an ambiguous completion.

LIST_TYPES (-X)
     When listing files that are possible completions, show the type of each file with a trailing identifying mark.

LOCAL_OPTIONS
     If this option is set at the point of return from a shell function, all the options (including this one) which were in force upon entry to the function are restored.  Otherwise, only this option and the XTRACE and PRINT_EXIT_VALUE options are restored.  Hence if this is explicitly unset by a shell function the other options in force at the point of return will remain so. A shell function can also guarantee itself a known shell configuration with a formulation like `emulate zsh; setopt localoptions'.

LOGIN (-l, ksh: -l)
     This is a login shell. If this option is not explicitly set, the shell is a login shell if the first character of the argv[0] passed to the shell is a `-'.

LONG_LIST_JOBS (-R)
     List jobs in the long format by default.

MAGIC_EQUAL_SUBST
     All unquoted arguments of the form `IDENTIFIER=EXPRESSION' appearing after the command name have filename expansion (that is, where EXPRESSION has a leading `~' or `=') performed on EXPRESSION as if it were a parameter assignment.  The argument is not otherwise treated specially; it is passed to the command as a single argument, and not used as an actual parameter assignment.

MAIL_WARNING (-U)
     Print a warning message if a mail file has been accessed since the shell last checked.

MARK_DIRS (-8, ksh: -X)
     Append a trailing `/' to all directory names resulting from filename generation (globbing).

MENU_COMPLETE (-Y)
     On an ambiguous completion, instead of listing possibilities or beeping, insert the first match immediately.  Then when completion is requested again, remove the first match and insert the second match, etc. When there are no more matches, go back to the first one again. reverse-menu-complete may be used to loop through the list in the other direction. This option overrides AUTO_MENU.

MONITOR (-m, ksh: -m)
     Allow job control.  Set by default in interactive shells.

MULTIOS
     Perform implicit tees or cats when multiple redirections are attempted (see Redirection).

NOMATCH (+3)
     If a pattern for filename generation has no matches, print an error, instead of leaving it unchanged in the argument list. This also applies to file expansion of an initial `~' or `='.

NOTIFY (-5, ksh: -b)
     Report the status of background jobs immediately, rather than waiting until just before printing a prompt.

NULL_GLOB (-G)
     If a pattern for filename generation has no matches, delete the pattern from the argument list instead of reporting an error.  Overrides NOMATCH.

NUMERIC_GLOB_SORT
     If numeric filenames are matched by a filename generation pattern, sort the filenames numerically rather than lexicographically.

OVERSTRIKE
     Start up the line editor in overstrike mode.

PATH_DIRS (-Q)
     Perform a path search even on command names with slashes in them. Thus if `/usr/local/bin' is in the user's path, and he types `X11/xinit', the command `/usr/local/bin/X11/xinit' will be executed (assuming it exists). Commands explicitly beginning with `/', `./' or `../' are not subject to the path search. This also applies to the . builtin, and searches for modules performed by the zmodload builtin.

POSIX_BUILTINS
     When this option is set the command builtin can be used to execute shell builtin commands.  Parameter assignments specified before shell functions and special builtins are kept after the command completes unless the special builtin is prefixed with the command builtin.  Special builtins are ., :, break, continue, declare, eval, exit, export, integer, local, readonly, return, set, shift, source, times, trap and unset.

PRINT_EIGHT_BIT
     Print eight bit characters literally in completion lists, etc. This option is not necessary if your system correctly returns the printability of eight bit characters (see man page ctype(3)).

PRINT_EXIT_VALUE (-1)
     Print the exit value of programs with non-zero exit status.

PRIVILEGED (-p, ksh: -p)
     Turn on privileged mode. This is enabled automatically on startup if the effective user (group) ID is not equal to the real user (group) ID.  Turning this option off causes the effective user and group IDs to be set to the real user and group IDs. This option disables sourcing user startup files. If zsh is invoked as `sh' or `ksh' with this option set, /etc/suid_profile is sourced (after /etc/profile on interactive shells). Sourcing ~/.profile is disabled and the contents of the ENV variable is ignored. This option cannot be changed using the -m option of setopt and unsetopt, and changing it inside a function always changes it globally regardless of the LOCAL_OPTIONS option.

PROMPT_BANG
     If set, `!' is treated specially in prompt expansion. See Prompt Expansion.

PROMPT_CR (+V)
     Print a carriage return just before printing a prompt in the line editor.

PROMPT_PERCENT
     If set, `%' is treated specially in prompt expansion. See Prompt Expansion.

PROMPT_SUBST
     If set, parameter expansion, command substitution and arithmetic expansion are performed in prompts.

PUSHD_IGNORE_DUPS
     Don't push multiple copies of the same directory onto the directory stack.

PUSHD_MINUS
     Exchanges the meanings of `+' and `-' when used with a number to specify a directory in the stack.

PUSHD_SILENT (-E)
     Do not print the directory stack after pushd or popd.

PUSHD_TO_HOME (-D)
     Have pushd with no arguments act like `pushd $HOME'.

RC_EXPAND_PARAM (-P)
     Array expansions of the form `FOO${XX}BAR', where the parameter XX is set to (A B C), are substituted with `FOOABAR FOOBBAR FOOCBAR' instead of the default `FOOA B CBAR'.

RC_QUOTES
     Allow the character sequence `' to signify a single quote within singly quoted strings.

RCS (+f)
     After /etc/zshenv is sourced on startup, source the .zshenv, /etc/zprofile, .zprofile, /etc/zshrc, .zshrc, /etc/zlogin, .zlogin, and .zlogout files, as described in Files. If this option is unset, only the /etc/zshenv file is sourced.

REC_EXACT (-S)
     In completion, recognize exact matches even if they are ambiguous.

RESTRICTED (-r)
     Enables restricted mode.  This option cannot be changed using unsetopt, and setting it inside a function always changes it globally regardless of the LOCAL_OPTIONS option.  See Restricted Shell.

RM_STAR_SILENT (-H)
     Do not query the user before executing `rm *' or `rm path/*'.

RM_STAR_WAIT
     If querying the user before executing `rm *' or `rm path/*', first wait ten seconds and ignore anything typed in that time. This avoids the problem of reflexively answering `yes' to the query when one didn't really mean it.  The wait and query can always be avoided by expanding the `*' in ZLE (with tab).

SH_FILE_EXPANSION
     Perform filename expansion (e.g., ~ expansion) before parameter expansion, command substitution, arithmetic expansion and brace expansion. If this option is unset, it is performed after brace expansion, so things like `~$USERNAME' and `~{pfalstad,rc}' will work.

SH_GLOB
     Disables the special meaning of `(', `|', `)' and '<' for globbing the result of parameter and command substitutions, and in some other places where the shell accepts patterns.  This option is set by default if zsh is invoked as sh or ksh.

SHIN_STDIN (-s, ksh: -s)
     Commands are being read from the standard input. Commands are read from standard input if no command is specified with -c and no file of commands is specified.  If SHIN_STDIN is set explicitly on the command line, any argument that would otherwise have been taken as a file to run will instead be treated as a normal positional parameter. Note that setting or unsetting this option on the command line does not necessarily affect the state the option will have while the shell is running - that is purely an indicator of whether on not commands are actually being read from standard input. The value of this option cannot be changed anywhere other than the command line.

SH_OPTION_LETTERS
     If this option is set the shell tries to interpret single letter options (which are used with set and setopt) like ksh does. This also affects the value of the - special parameter.

SHORT_LOOPS
     Allow the short forms of for, select, if, and function constructs.

SH_WORD_SPLIT (-y)
     Causes field splitting to be performed on unquoted parameter expansions. Note that this option has nothing to do with word splitting. (See Parameter Expansion.)

SINGLE_COMMAND (-t, ksh: -t)
     If the shell is reading from standard input, it exits after a single command has been executed.  This also makes the shell non-interactive, unless the INTERACTIVE option is explicitly set on the command line. The value of this option cannot be changed anywhere other than the command line.

SINGLE_LINE_ZLE (-M)
     Use single-line command line editing instead of multi-line.

SUN_KEYBOARD_HACK (-L)
     If a line ends with a backquote, and there are an odd number of backquotes on the line, ignore the trailing backquote. This is useful on some keyboards where the return key is too small, and the backquote key lies annoyingly close to it.

UNSET (+u, ksh: +u)
     Treat unset parameters as if they were empty when substituting. Otherwise they are treated as an error.

VERBOSE (-v, ksh: -v)
     Print shell input lines as they are read.

XTRACE (-x, ksh: -x)
     Print commands and their arguments as they are executed.

ZLE (-Z)
     Use the zsh line editor.

Option Aliases
==============

Some options have alternative names.  These aliases are never used for output, but can be used just like normal option names when specifying options to the shell.

BRACE_EXPAND
     NO_IGNORE_BRACES (ksh and bash compatibility)

DOT_GLOB
     GLOB_DOTS (bash compatibility)

HASH_ALL
     HASH_CMDS (bash compatibility)

HIST_APPEND
     APPEND_HISTORY (bash compatibility)

HIST_EXPAND
     BANG_HIST (bash compatibility)

LOG
     NO_HIST_NO_FUNCTIONS (ksh compatibility)

MAIL_WARN
     MAIL_WARNING (bash compatibility)

ONE_CMD
     SINGLE_COMMAND (bash compatibility)

PHYSICAL
     CHASE_LINKS (ksh and bash compatibility)

PROMPT_VARS
     PROMPT_SUBST (bash compatibility)

STDIN
     SHIN_STDIN (ksh compatibility)

TRACK_ALL
     HASH_CMDS (ksh compatibility)

Single Letter Options
=====================

Default set
-----------

-0
     CORRECT

-1
     PRINT_EXIT_VALUE

-2
     NO_BAD_PATTERN

-3
     NO_NOMATCH

-4
     GLOB_DOTS

-5
     NOTIFY

-6
     BG_NICE

-7
     IGNORE_EOF

-8
     MARK_DIRS

-9
     AUTO_LIST

-B
     NO_BEEP

-C
     NO_CLOBBER

-D
     PUSHD_TO_HOME

-E
     PUSHD_SILENT

-F
     NO_GLOB

-G
     NULL_GLOB

-H
     RM_STAR_SILENT

-I
     IGNORE_BRACES

-J
     AUTO_CD

-K
     NO_BANG_HIST

-L
     SUN_KEYBOARD_HACK

-M
     SINGLE_LINE_ZLE

-N
     AUTO_PUSHD

-O
     CORRECT_ALL

-P
     RC_EXPAND_PARAM

-Q
     PATH_DIRS

-R
     LONG_LIST_JOBS

-S
     REC_EXACT

-T
     CDABLE_VARS

-U
     MAIL_WARNING

-V
     NO_PROMPT_CR

-W
     AUTO_RESUME

-X
     LIST_TYPES

-Y
     MENU_COMPLETE

-Z
     ZLE

-a
     ALL_EXPORT

-e
     ERR_EXIT

-f
     NO_RCS

-g
     HIST_IGNORE_SPACE

-h
     HIST_IGNORE_DUPS

-i
     INTERACTIVE

-k
     INTERACTIVE_COMMENTS

-l
     LOGIN

-m
     MONITOR

-n
     NO_EXEC

-p
     PRIVILEGED

-r
     RESTRICTED

-s
     SHIN_STDIN

-t
     SINGLE_COMMAND

-u
     NO_UNSET

-v
     VERBOSE

-w
     CHASE_LINKS

-x
     XTRACE

-y
     SH_WORD_SPLIT

sh/ksh emulation set
--------------------

-C
     NO_CLOBBER

-X
     MARK_DIRS

-a
     ALL_EXPORT

-b
     NOTIFY

-e
     ERR_EXIT

-f
     NO_GLOB

-i
     INTERACTIVE

-l
     LOGIN

-m
     MONITOR

-n
     NO_EXEC

-p
     PRIVILEGED

-r
     RESTRICTED

-s
     SHIN_STDIN

-t
     SINGLE_COMMAND

-u
     NO_UNSET

-v
     VERBOSE

-x
     XTRACE

Also note
---------

-A
     Used by set for setting arrays

-c
     Used on the command line to specify a single command

-m
     Used by setopt for pattern-matching option setting

-o
     Used in all places to allow use of long option names

-s
     Used by set to sort positional parameters

Shell Builtin Commands
**********************

- SIMPLE COMMAND
     See Precommand Modifiers.

. FILE [ ARG ... ]
     Read commands from FILE and execute them in the current shell environment. If FILE does not contain a slash, or if PATH_DIRS is set, the shell looks in the components of $path to find the directory containing FILE. Files in the current directory are not read unless `.' appears somewhere in $path.

     If any arguments ARG are given, they become the positional parameters; the old positional parameters are restored when the FILE is done executing. The exit status is the exit status of the last command executed.

: [ ARG ... ]
     This command 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 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 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
     Same as functions -u.

bg [ JOB ... ]
JOB ... &
     Put each specified JOB in the background, or the current job if none is specified.

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 [ -sLP ] [ ARG ]
cd [ -sLP ] OLD NEW
cd [ -sLP ] {+|-}N
     Change the current directory.  In the first form, change the current directory to ARG, or to the value of $HOME if ARG is not specified.  If ARG is `-', change to the value of $OLDPWD, the previous directory. If a directory named ARG is not found in the current directory and ARG does not begin with a slash, search each component of the shell parameter cdpath. If the option CDABLE_VARS 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 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 -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 followed regardless of the state of the CHASE_LINKS option.

chdir
     Same as cd.

command SIMPLE COMMAND
     See Precommand Modifiers.

continue [ N ]
     Resume the next iteration of the enclosing for, while, until, select or repeat loop.  If N is specified, break out of N-1 loops and resume at the Nth enclosing loop.

declare
     Same as typeset.

dirs [ -v ] [ ARG ... ]
     With no arguments, print the contents of the directory 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 ] NAME ...
     Temporarily disable the NAMEd hash table elements.  The default is to disable builtin commands.  This allows you to use an external command with the same name as a builtin command.  The -a option causes disable to act on 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 (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 ... &!
     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.

echo [ -neE ] [ ARG ... ]
     Write each ARG on the standard output, with a space separating each one. If the -n flag is not present, print a newline at the end. echo recognizes the following escape sequences:

     \a
          bell character

     \b
          backspace

     \c
          suppress final newline

     \e
          escape

     \f
          form feed

     \n
          linefeed (newline)

     \r
          carriage return

     \t
          horizontal tab

     \v
          vertical tab

     \\
          backslash

     \0NNN
          character code in octal

     \xNN
          character code in hexadecimal

     The -E flag, or the BSD_ECHO option, can be used to disable these escape sequences.  In the latter case, -e flag can be used to enable them.

echotc CAP [ ARG ... ]
     Output the termcap string corresponding to the capability CAP, with optional arguments.

emulate [ -R ] {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.

enable [ -afmr ] 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 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.

eval [ ARG ... ]
     Read the arguments as input to the shell and execute the resulting command in the current shell process.

exec SIMPLE COMMAND
     See Precommand Modifiers.

exit [ N ]
     Exit the shell with the exit code specified by N; if none is specified, use the exit code from the last command executed. An EOF condition will also cause the shell to exit, unless the IGNORE_EOF option is set.

export [ NAME[=VALUE] ... ]
     The specified NAMEs are marked for automatic export to the environment of subsequently executed commands. Equivalent to typeset -x, except that no parameter will be created to hide an existing one in an outer scope. If a parameter specified does not already exist, it is created in the global scope.

false [ ARG ... ]
     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 offset to the current history event number. A string specifies the most recent event beginning with the given string. All substitutions OLD=NEW, if any, are then performed on the commands.

     If the -l flag is given, the resulting commands are listed on standard output. If the -m flag is also given the first argument is taken as a pattern (should be quoted) and only the history events matching this pattern will be shown. Otherwise the editor program 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 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 numbers 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 in ISO8601 `YYYY-MM-DD' 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. If the -I option is added, only those events that are new since last incremental append (write) to the history file are appended (written). In any case the 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.

functions [ {+|-}tum ] [ NAME ... ]
     Equivalent to typeset -f.

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. OPTSTRING contains the letters that getopts recognizes.  If a letter is followed by a `:', that option is expected to have an argument.  The options can be separated from the argument by blanks.

     Each time it is invoked, getopts places the option letter it finds in the shell parameter NAME, prepended with a `+' when ARG begins with a `+'.  The index of the next ARG is stored in OPTIND.  The option argument, if any, is stored in OPTARG.

     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 [ -dfmrv ] [ 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.

     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 (they 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.

history
     Same as fc -l.

integer [ {+|-}lrtux ] [ 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 (man page ps(1)) listings.  This feature is typically used by daemons, to indicate their state.

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 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.

let ARG ...
     Evaluate each ARG as an arithmetic expression. See Arithmetic Evaluation for a description of arithmetic 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 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.

     RESOURCE can be one of:

     memorylocked
          Maximum amount of memory locked in RAM.

     resident
          Maximum resident set size.

     vmemorysize
          Maximum amount of virtual memory.

     descriptors
          Maximum value for a file descriptor.

     coredumpsize
          Maximum size of a core dump.

     stacksize
          Maximum stack size for each process.

     datasize
          Maximum data size (including stack) for each process.

     filesize
          Largest single file allowed.

     cputime
          Maximum CPU seconds per process.

     maxproc
          Maximum number of processes.

     addressspace
          Maximum amount of address space used.

     cachedthreads
          Maximum number of cached threads.

     Which of these resource limits are available depends on the system. RESOURCE can be abbreviated to any unambiguous prefix.

     LIMIT is a number, with an optional scaling factor, as follows:

     Nh
          hours

     Nk
          kilobytes (default)

     Nm
          megabytes or minutes

     [MM:]SS
          minutes and seconds

local [ {+|-}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 [ N ]
     Same as exit, except that it only works in a login shell.

noglob SIMPLE COMMAND
     See Precommand Modifiers.

popd [ {+|-}N ]
     Removes a 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.

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 `\M-X' metafies the character X (sets the highest bit), `\C-X' produces a control character (`\C-@' and `\C-?' give the characters NUL and delete), and `\E' is a synonym for `\e'. Finally, if not in an escape sequence, `\' escapes the following character and is not printed.

     -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 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.

     -s
          Place the results in the history list instead 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 order.

     -O
          Print the arguments sorted in descending order.

     -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 coprocess.

     -z
          Push the arguments onto the editing buffer stack, separated by spaces; no escape sequences are recognized.

     -D
          Treat the arguments as directory names, replacing prefixes with ~ expressions, as appropriate.

     -P
          Perform prompt expansion (see Prompt Expansion).

pushd [ ARG ]
pushd OLD NEW
pushd {+|-}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.

     If ARG is `-', change to $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 CDABLE_VARS 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 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.

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 [ -rzpqAclneE ] [ -k [ NUM ] ] [ -uN ] [ 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.

     -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'.  Note that this always reads from the terminal, even if used with the -p or -u or -z flags or with redirected input.

     -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.

     -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 Zsh Line Editor).  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.  If NAME is omitted then REPLY is used for scalars and reply for arrays.

     -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.

     -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 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.  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.

rehash
     Same as hash -r.

return [ N ]
     Causes a shell function or . script to return to the invoking script with the return status specified by N.  If N is omitted, the return status is that of the last command executed.

     If return was executed from a trap in a TRAPNAL function, the effect is different for zero and non-zero return status.  With zero status (or after an implicit return at the end of the trap), the shell will return to whatever it was previously 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 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.

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 Options.  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 given arguments will replace the initial elements of that array; if no NAME is specified, 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 | {+|-}o OPTION_NAME ] [ NAME ... ]
     Set the options for the shell.  All options specified either with flags or by name are set.  If no arguments are supplied, the names of all options currently set are printed. 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 set.

shift [ N ] [ NAME ... ]
     The positional parameters ${N+1} ... are renamed to $1 ..., where N is an arithmetic expression that defaults to 1. If any NAMEs are given then the arrays with these names are shifted instead of the positional parameters.

source FILE [ ARG ... ]
     Same as ., except that the current directory is always searched and is always searched first, before directories in $path.

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 Conditional Expressions).

times
     Print the accumulated user and system times for the shell and for processes run from the shell.

trap [ ARG [ SIG ... ] ]
     ARG is a command 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 commands 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.

true [ ARG ... ]
     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 exits or is suspended.  Thus, stty and similar programs have no effect when the tty is frozen.  Without options it reports whether the terminal is frozen or not.

type [ -wfpams ] NAME ...
     Equivalent to whence -v.

typeset [ {+|-}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 ALL_EXPORT is set, in which case the parameter will be exported provided no parameter of that name already 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; otherwise 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 parameters.  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 Functions.

     -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 arguments are taken as patterns (should be quoted) and all parameters 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 number 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 assumed.  If LIMIT is omitted the current value of the specified resources are printed.  When more than one resource values are printed the limit name and unit is printed before each value.

     -a
          Lists all of the current resource limits.

     -c
          512-byte blocks on the size of core dumps.

     -d
          K-bytes on the size of the data segment.

     -f
          512-byte blocks on the size of files written.

     -l
          K-bytes on the size of locked-in memory.

     -m
          K-bytes on the size of physical memory.

     -n
          open file descriptors.

     -s
          K-bytes on the size of the stack.

     -t
          CPU seconds to be used.

     -u
          processes available to the user.

     -v
          K-bytes on the size of virtual memory.

umask [ -S ] [ MASK ]
     The umask is set to MASK.  MASK can be either an octal number or a symbolic value as described in man page chmod(1). If MASK is omitted, the current value is printed.  The -S option causes the mask to be printed as a symbolic value.  Otherwise, the mask is printed as an octal number.  Note that in the symbolic form the permissions you specify are those which are to be allowed (not denied) to the users specified.

unalias
     Same as unhash -a.

unfunction
     Same as unhash -f.

unhash [ -adfm ] 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 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.

unset [ -fm ] 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.

     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 | {+|-}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.

wait [ JOB ... ]
     Wait for the specified jobs or processes.  If JOB is not given then all currently active child processes are waited for. Each JOB can be either a job specification or the process ID of a job in the job table. The exit status from this command is that of the job waited for.

whence [ -vcwfpams ] NAME ...
     For each name, indicate how it would be interpreted if used as a command name.

     -v
          Produce a more verbose report.

     -c
          Print the results in a csh-like format. This takes precedence over -v.

     -w
          For each NAME, print `NAME: WORD' where WORD is one of alias, builtin, command, function, hashed, reserved or none, according as NAME corresponds to an alias, a built-in command, an external command, a shell function, a command defined with the hash builtin, a reserved word, or is not recognised.  This takes precedence over -v and -c.

     -f
          Causes the contents of a shell function to be displayed, which would otherwise not happen unless the -c flag were used.

     -p
          Do a path search for NAME even if it is an alias, reserved word, shell function or builtin.

     -a
          Do a search for all occurrences of NAME throughout the command path. Normally only the first occurrence is printed.

     -m
          The arguments are taken as patterns (should be quoted), and the information is displayed for each command matching one of these patterns.

     -s
          If a pathname contains symlinks, print the symlink-free pathname as well.

where [ -wpms ] NAME ...
     Equivalent to whence -ca.

which [ -wpams ] NAME ...
     Equivalent to whence -c.

zmodload [ -iL ] [ NAME ... ]
zmodload -u [ -i ] NAME ...
zmodload -d [ -L ] [ NAME [ DEP ... ] ]
zmodload -du NAME [ DEP ... ]
zmodload -a [ -iL ] [ NAME [ BUILTIN ... ] ]
zmodload -au [ -i ] BUILTIN ...
     zmodload performs operations relating to zsh's loadable modules. This feature is not available on all operating systems, or on all installations on a particular operating system.

     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'.  If this can't be found, the NAME is tried without the suffix. If the module to be loaded is already loaded and the -i option is given, the duplicate module is ignored.  Otherwise zmodload prints an error message.

     The NAMEd module is searched for in the same way a command is, using $module_path instead of $path.  If NAME contains a `/', it will be used as-is, and a path search will be performed otherwise. This behaviour can be modified by the PATH_DIRS option.

     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 filesystem. 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.

     Without arguments all currently loaded binary modules are printed. The -L option causes this list to be in the form of a series of zmodload commands.

     The -d option can be used to specify module dependencies. This operation is idempotent regardless of the -i option. 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. This operation is idempotent regardless of the -i option. If only one argument is given, all dependencies for that module are removed.

     The -a 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.  If only one argument 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, regardless of which module it came from.

     With -a 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 -a is used together with the -u option it removes builtins defined with zmodload -a.  This is only possible if the builtin is not yet loaded.  -i suppresses the error if the builtin is already removed (or never existed).

Zsh Line Editor
***************

Description
===========

If the ZLE option is set (it is by default) and the shell input is attached to the terminal, the user is allowed to edit command lines.

There are two display modes.  The first, multiline mode, is the default.  It only works if the TERM parameter is set to a valid terminal type that can move the cursor up.  The second, single line mode, is used if TERM is invalid or incapable of moving the cursor up, or if the SINGLE_LINE_ZLE option is set. This mode is similar to ksh, and uses no termcap sequences.  If TERM is "emacs", the ZLE option will be unset by default.

Keymaps
=======

A keymap in ZLE contains a set of bindings between key sequences and ZLE commands.  The empty key sequence cannot be bound.

There can be any number of keymaps at any time, and each keymap has one or more names.  If all of a keymap's names are deleted, it disappears. bindkey can be used to manipulate keymap names.

Initially, there are four keymaps:

emacs
     EMACS emulation

viins
     vi emulation - insert mode

vicmd
     vi emulation - command mode

.safe
     fallback keymap

The `.safe' keymap is special.  It can never be altered, and the name can never be removed.  However, it can be linked to other names, which can be removed.  In the future other special keymaps may be added; users should avoid using names beginning with `.' for their own keymaps.

In addition to these four names, either `emacs' or `viins' is also linked to the name `main'.  If one of the VISUAL or EDITOR environment variables contain the string `vi' when the shell starts up then it will be `viins', otherwise it will be `emacs'. bindkey's -e and -v options provide a convenient way to override this default choice.

When the editor starts up, it will select the `main' keymap. If that keymap doesn't exist, it will use `.safe' instead.

In the `.safe' keymap, each single key is bound to self-insert, except for ^J (line feed) and ^M (return) which are bound to accept-line. This is deliberately not pleasant to use; if you are using it, it means you deleted the main keymap, and you should put it back.

Reading Commands
----------------

When ZLE is reading a command from the terminal, it may read a sequence that is bound to some command and is also a prefix of a longer bound string. In this case ZLE will wait a certain time to see if more characters are typed, and if not (or they don't match any longer string) it will execute the binding.  This timeout is defined by the KEYTIMEOUT parameter; its default is 0.4 sec.  No timeout is done if the prefix string is not bound.

As well as ZLE commands, key sequences can be bound to other strings, by using `bindkey -s'. When such a sequence is read, the replacement string is pushed back as input, and the command reading process starts again using these fake keystrokes. This input can itself invoke further replacement strings, but in order to detect loops the process will be stopped if there are twenty such replacements without a real command being read.

Widgets
=======

All actions in the editor are performed by `widgets'.  A widget's job is simply to perform some small action.  The ZLE commands that key sequences in keymaps are bound to are in fact widgets.  Widgets can be user-defined or built in.

There are 162 standard widgets built in to ZLE (see sectref(Standard Widgets)). Other built-in widgets can be defined by other modules (see Zsh Modules).  Each built-in widget has two names: its normal canonical name, and the same name preceded by a `.'.  The `.' name is special: it can't be rebound to a different widget.  This makes the widget available even when its usual name has been redefined.

User-defined widgets are defined using `zle -N', and implemented as shell functions.  When the widget is executed, the corresponding shell function is executed, and can perform editing (or other) actions. It is recommended that user-defined widgets should not have names starting with `.'.

User-Defined Widgets
====================

User-defined widgets, being implemented as shell functions, can execute any normal shell command.  They can also run other widgets (whether built-in or user-defined) using the zle builtin command. Finally, they can examine and edit the ZLE buffer being edited by reading and setting the special parameters described below.

These special parameters are always available in widget functions, but are not in any way special outside ZLE.  If they have some normal value outside ZLE, that value is temporarily inaccessible, but will return when the widget function exits.  These special parameters in fact have local scope, like parameters created in a function using local.

BUFFER (scalar)
     The entire contents of the edit buffer.  If it is written to, the cursor remains at the same offset, unless that would put it outside the buffer.

CURSOR (integer)
     The offset of the cursor, within the edit buffer.  This is in the range 0 to $#BUFFER, and is by definition equal to $#LBUFFER. Attempts to move the cursor outside the buffer will result in the cursor being moved to the appropriate end of the buffer.

LBUFFER (scalar)
     The part of the buffer that lies to the left of the cursor position. If it is assigned to, only that part of the buffer is replaced, and the cursor remains between the new $LBUFFER and the old $RBUFFER.

RBUFFER (scalar)
     The part of the buffer that lies to the right of the cursor position. If it is assigned to, only that part of the buffer is replaced, and the cursor remains between the old $LBUFFER and the new $RBUFFER.

Standard Widgets
================

The following is a list of all the standard widgets, and their default bindings in emacs mode, vi command mode and vi insert mode (the `emacs', `vicmd' and `viins' keymaps, respectively).

Movement
--------

vi-backward-blank-word (unbound) (B) (unbound)
     Move backward one word, where a word is defined as a series of non-blank characters.

backward-char (^B ESC-[D) (unbound) (unbound)
     Move backward one character.

vi-backward-char (unbound) (^H h ^?) (unbound)
     Move backward one character, without changing lines.

backward-word (ESC-B ESC-b) (unbound) (unbound)
     Move to the beginning of the previous word.

emacs-backward-word
     Move to the beginning of the previous word.

vi-backward-word (unbound) (b) (unbound)
     Move to the beginning of the previous word, vi-style.

beginning-of-line (^A) (unbound) (unbound)
     Move to the beginning of the line.  If already at the beginning of the line, move to the beginning of the previous line, if any.

vi-beginning-of-line
     Move to the beginning of the line, without changing lines.

end-of-line (^E) (unbound) (unbound)
     Move to the end of the line.  If already at the end of the line, move to the end of the next line, if any.

vi-end-of-line (unbound) ($) (unbound)
     Move to the end of the line. If an argument is given to this command, the cursor will be moved to the end of the line (argument - 1) lines down.

vi-forward-blank-word (unbound) (W) (unbound)
     Move forward one word, where a word is defined as a series of non-blank characters.

vi-forward-blank-word-end (unbound) (E) (unbound)
     Move to the end of the current word, or, if at the end of the current word, to the end of the next word, where a word is defined as a series of non-blank characters.

forward-char (^F ESC-[C) (unbound) (unbound)
     Move forward one character.

vi-forward-char (unbound) (space l) (unbound)
     Move forward one character.

vi-find-next-char (^X^F) (f) (unbound)
     Read a character from the keyboard, and move to the next occurrence of it in the line.

vi-find-next-char-skip (unbound) (t) (unbound)
     Read a character from the keyboard, and move to the position just before the next occurrence of it in the line.

vi-find-prev-char (unbound) (F) (unbound)
     Read a character from the keyboard, and move to the previous occurrence of it in the line.

vi-find-prev-char-skip (unbound) (T) (unbound)
     Read a character from the keyboard, and move to the position just after the previous occurrence of it in the line.

vi-first-non-blank (unbound) (^) (unbound)
     Move to the first non-blank character in the line.

vi-forward-word (unbound) (w) (unbound)
     Move forward one word, vi-style.

forward-word (ESC-F ESC-f) (unbound) (unbound)
     Move to the beginning of the next word. The editor's idea of a word is specified with the WORDCHARS parameter.

emacs-forward-word
     Move to the end of the next word.

vi-forward-word-end (unbound) (e) (unbound)
     Move to the end of the next word.

vi-goto-column (ESC-|) (|) (unbound)
     Move to the column specified by the numeric argument.

vi-goto-mark (unbound) (`) (unbound)
     Move to the specified mark.

vi-goto-mark-line (unbound) (') (unbound)
     Move to beginning of the line containing the specified mark.

vi-repeat-find (unbound) (;) (unbound)
     Repeat the last vi-find command.

vi-rev-repeat-find (unbound) (,) (unbound)
     Repeat the last vi-find command in the opposite direction.

History Control
---------------

beginning-of-buffer-or-history (ESC-<) (unbound) (unbound)
     Move to the beginning of the buffer, or if already there, move to the first event in the history list.

beginning-of-line-hist
     Move to the beginning of the line.  If already at the beginning of the buffer, move to the previous history line.

beginning-of-history
     Move to the first event in the history list.

down-line-or-history (^N ESC-[B) (j) (unbound)
     Move down a line in the buffer, or if already at the bottom line, move to the next event in the history list.

vi-down-line-or-history (unbound) (+) (unbound)
     Move down a line in the buffer, or if already at the bottom line, move to the next event in the history list. Then move to the first non-blank character on the line.

down-line-or-search
     Move down a line in the buffer, or if already at the bottom line, search forward in the history for a line beginning with the first word in the buffer.

down-history (unbound) (^N) (unbound)
     Move to the next event in the history list.

history-beginning-search-backward
     Search backward in the history for a line beginning with the current line up to the cursor. This leaves the cursor in its original position.

end-of-buffer-or-history (ESC->) (unbound) (unbound)
     Move to the end of the buffer, or if already there, move to the last event in the history list.

end-of-line-hist
     Move to the end of the line.  If already at the end of the buffer, move to the next history line.

end-of-history
     Move to the last event in the history list.

vi-fetch-history (unbound) (G) (unbound)
     Fetch the history line specified by the numeric argument. This defaults to the current history line (i.e. the one that isn't history yet).

history-incremental-search-backward (^R ^Xr) (unbound) (unbound)
     Search backward incrementally for a specified string.  The search is case-insensitive if the search string does not have uppercase letters and no numeric argument was given.  The string may begin with `^' to anchor the search to the beginning of the line.

     A restricted set of editing functions is available in the mini-buffer.  An interrupt signal, as defined by the stty setting, will stop the search and go back to the original line.  An undefined key will have the same effect. The supported functions are: backward-delete-char, vi-backward-delete-char, clear-screen, redisplay, quoted-insert, vi-quoted-insert, accept-and-hold, accept-and-infer-next-history, accept-line and accept-line-and-down-history.

     magic-space just inserts a space. vi-cmd-mode toggles between the `main' and `vicmd' keymaps; the `main' keymap (insert mode) will be selected initially. history-incremental-search-backward will get the next occurrence of the contents of the mini-buffer. history-incremental-search-forward inverts the sense of the search. vi-repeat-search and vi-rev-repeat-search are similarly supported. The direction of the search is indicated in the mini-buffer.

     Any multi-character string that is not bound to one of the above functions will beep and interrupt the search, leaving the last found line in the buffer. Any single character that is not bound to one of the above functions, or self-insert or self-insert-unmeta, will have the same effect but the function will be executed.

history-incremental-search-forward (^S ^Xs) (unbound) (unbound)
     Search forward incrementally for a specified string.  The search is case-insensitive if the search string does not have uppercase letters and no numeric argument was given.  The string may begin with `^' to anchor the search to the beginning of the line.  The functions available in the mini-buffer are the same as for history-incremental-search-backward.

history-search-backward (ESC-P ESC-p) (unbound) (unbound)
     Search backward in the history for a line beginning with the first word in the buffer.

vi-history-search-backward (unbound) (/) (unbound)
     Search backward in the history for a specified string. The string may begin with `^' to anchor the search to the beginning of the line.

     A restricted set of editing functions is available in the mini-buffer.  An interrupt signal, as defined by the stty setting,  will stop the search. The functions available in the mini-buffer are: accept-line, backward-delete-char, vi-backward-delete-char, backward-kill-word, vi-backward-kill-word, clear-screen, redisplay, quoted-insert and vi-quoted-insert.

     vi-cmd-mode is treated the same as accept-line, and magic-space is treated as a space. Any other character that is not bound to self-insert or self-insert-unmeta will beep and be ignored. If the function is called from vi command mode, the bindings of the current insert mode will be used.

history-search-forward (ESC-N ESC-n) (unbound) (unbound)
     Search forward in the history for a line beginning with the first word in the buffer.

vi-history-search-forward (unbound) (?) (unbound)
     Search forward in the history for a specified string. The string may begin with `^' to anchor the search to the beginning of the line. The functions available in the mini-buffer are the same as for vi-history-search-backward.

infer-next-history (^X^N) (unbound) (unbound)
     Search in the history list for a line matching the current one and fetch the event following it.

insert-last-word (ESC-_ ESC-.) (unbound) (unbound)
     Insert the last word from the previous history event at the cursor position.  If a positive numeric argument is given, insert that word from the end of the previous history event. If the argument is zero or negative insert that word from the left (zero inserts the previous command word).

vi-repeat-search (unbound) (n) (unbound)
     Repeat the last vi history search.

vi-rev-repeat-search (unbound) (N) (unbound)
     Repeat the last vi history search, but in reverse.

up-line-or-history (^P ESC-[A) (k) (unbound)
     Move up a line in the buffer, or if already at the top line, move to the previous event in the history list.

vi-up-line-or-history (unbound) (-) (unbound)
     Move up a line in the buffer, or if already at the top line, move to the previous event in the history list. Then move to the first non-blank character on the line.

up-line-or-search
     Move up a line in the buffer, or if already at the top line, search backward in the history for a line beginning with the first word in the buffer.

up-history (unbound) (^P) (unbound)
     Move to the previous event in the history list.

history-beginning-search-forward
     Search forward in the history for a line beginning with the current line up to the cursor. This leaves the cursor in its original position.

Modifying Text
--------------

vi-add-eol (unbound) (A) (unbound)
     Move to the end of the line and enter insert mode.

vi-add-next (unbound) (a) (unbound)
     Enter insert mode after the current cursor position, without changing lines.

backward-delete-char (^H ^?) (unbound) (unbound)
     Delete the character behind the cursor.

vi-backward-delete-char (unbound) (X) (^H)
     Delete the character behind the cursor, without changing lines. If in insert mode, this won't delete past the point where insert mode was last entered.

backward-delete-word
     Delete the word behind the cursor.

backward-kill-line
     Kill from the beginning of the line to the cursor position.

backward-kill-word (^W ESC-^H ESC-^?) (unbound) (unbound)
     Kill the word behind the cursor.

vi-backward-kill-word (unbound) (unbound) (^W)
     Kill the word behind the cursor, without going past the point where insert mode was last entered.

capitalize-word (ESC-C ESC-c) (unbound) (unbound)
     Capitalize the current word and move past it.

vi-change (unbound) (c) (unbound)
     Read a movement command from the keyboard, and kill from the cursor position to the endpoint of the movement. Then enter insert mode. If the command is vi-change, change the current line.

vi-change-eol (unbound) (C) (unbound)
     Kill to the end of the line and enter insert mode.

vi-change-whole-line (unbound) (S) (unbound)
     Kill the current line and enter insert mode.

copy-region-as-kill (ESC-W ESC-w) (unbound) (unbound)
     Copy the area from the cursor to the mark to the kill buffer.

copy-prev-word (ESC-^_) (unbound) (unbound)
     Duplicate the word behind the cursor.

vi-delete (unbound) (d) (unbound)
     Read a movement command from the keyboard, and kill from the cursor position to the endpoint of the movement. If the command is vi-delete, kill the current line.

delete-char
     Delete the character under the cursor.

vi-delete-char (unbound) (x) (unbound)
     Delete the character under the cursor, without going past the end of the line.

delete-word
     Delete the current word.

down-case-word (ESC-L ESC-l) (unbound) (unbound)
     Convert the current word to all lowercase and move past it.

kill-word (ESC-D ESC-d) (unbound) (unbound)
     Kill the current word.

gosmacs-transpose-chars
     Exchange the two characters behind the cursor.

vi-indent (unbound) (>) (unbound)
     Indent a number of lines.

vi-insert (unbound) (i) (unbound)
     Enter insert mode.

vi-insert-bol (unbound) (I) (unbound)
     Move to the first non-blank character on the line and enter insert mode.

vi-join (^X^J) (J) (unbound)
     Join the current line with the next one.

kill-line (^K) (unbound) (unbound)
     Kill from the cursor to the end of the line. If already on the end of the line, kill the newline character.

vi-kill-line (unbound) (unbound) (^U)
     Kill from the cursor back to wherever insert mode was last entered.

vi-kill-eol (unbound) (D) (unbound)
     Kill from the cursor to the end of the line.

kill-region
     Kill from the cursor to the mark.

kill-buffer (^X^K) (unbound) (unbound)
     Kill the entire buffer.

kill-whole-line (^U) (unbound) (unbound)
     Kill the current line.

vi-match-bracket (^X^B) (%) (unbound)
     Move to the bracket character (one of {}, () or []) that matches the one under the cursor. If the cursor is not on a bracket character, move forward without going past the end of the line to find one, and then go to the matching bracket.

vi-open-line-above (unbound) (O) (unbound)
     Open a line above the cursor and enter insert mode.

vi-open-line-below (unbound) (o) (unbound)
     Open a line below the cursor and enter insert mode.

vi-oper-swap-case
     Read a movement command from the keyboard, and swap the case of all characters from the cursor position to the endpoint of the movement. If the movement command is vi-oper-swap-case, swap the case of all characters on the current line.

overwrite-mode (^X^O) (unbound) (unbound)
     Toggle between overwrite mode and insert mode.

vi-put-before (unbound) (P) (unbound)
     Insert the contents of the kill buffer before the cursor. If the kill buffer contains a sequence of lines (as opposed to characters), paste it above the current line.

vi-put-after (unbound) (p) (unbound)
     Insert the contents of the kill buffer after the cursor. If the kill buffer contains a sequence of lines (as opposed to characters), paste it below the current line.

quoted-insert (^V) (unbound) (unbound)
     Insert the next character typed into the buffer literally. An interrupt character will not be inserted.

vi-quoted-insert (unbound) (unbound) (^Q ^V)
     Display a `^' at the cursor position, and insert the next character typed into the buffer literally. An interrupt character will not be inserted.

quote-line (ESC-') (unbound) (unbound)
     Quote the current line; that is, put a `'' character at the beginning and the end, and convert all `'' characters to `'\'.

quote-region (ESC-") (unbound) (unbound)
     Quote the region from the cursor to the mark.

vi-replace (unbound) (R) (unbound)
     Enter overwrite mode.

vi-repeat-change (unbound) (.) (unbound)
     Repeat the last vi mode text modification. If a count was used with the modification, it is remembered. If a count is given to this command, it overrides the remembered count, and is remembered for future uses of this command. The cut buffer specification is similarly remembered.

vi-replace-chars (unbound) (r) (unbound)
     Replace the character under the cursor with a character read from the keyboard.

self-insert (printable characters) (unbound) (printable characters and some control characters)
     Insert a character into the buffer at the cursor position.

self-insert-unmeta (ESC-^I ESC-^J ESC-^M) (unbound) (unbound)
     Insert a character into the buffer after stripping the meta bit and converting ^M to ^J.

vi-substitute (unbound) (s) (unbound)
     Substitute the next character(s).

vi-swap-case (unbound) (~) (unbound)
     Swap the case of the character under the cursor and move past it.

transpose-chars (^T) (unbound) (unbound)
     Exchange the two characters to the left of the cursor if at end of line, else exchange the character under the cursor with the character to the left.

transpose-words (ESC-T ESC-t) (unbound) (unbound)
     Exchange the current word with the one before it.

vi-unindent (unbound) (<) (unbound)
     Unindent a number of lines.

up-case-word (ESC-U ESC-u) (unbound) (unbound)
     Convert the current word to all caps and move past it.

yank (^Y) (unbound) (unbound)
     Insert the contents of the kill buffer at the cursor position.

yank-pop (ESC-y) (unbound) (unbound)
     Remove the text just yanked, rotate the kill-ring, and yank the new top.  Only works following yank or yank-pop.

vi-yank (unbound) (y) (unbound)
     Read a movement command from the keyboard, and copy the region from the cursor position to the endpoint of the movement into the kill buffer. If the command is vi-yank, copy the current line.

vi-yank-whole-line (unbound) (Y) (unbound)
     Copy the current line into the kill buffer.

vi-yank-eol
     Copy the region from the cursor position to the end of the line into the kill buffer. Arguably, this is what Y should do in vi, but it isn't what it actually does.

Arguments
---------

digit-argument (ESC-0..ESC-9) (1-9) (unbound)
     Start a new numeric argument, or add to the current one. See also vi-digit-or-beginning-of-line.

neg-argument (ESC--) (unbound) (unbound)
     Changes the sign of the following argument.

universal-argument
     Multiply the argument of the next command by 4.  Alternatively, if this command is followed by an integer (positive or negative), use that as the argument for the next command.  Thus digits cannot be repeated using this command.  For example, if this command occurs twice, followed immediately by forward-char, move forward sixteen spaces; if instead it is followed by -2, then forward-char, move backward two spaces.

Completion
----------

accept-and-menu-complete
     In a menu completion, insert the current completion into the buffer, and advance to the next possible completion.

complete-word
     Attempt completion on the current word.

delete-char-or-list (^D) (unbound) (unbound)
     Delete the character under the cursor.  If the cursor is at the end of the line, list possible completions for the current word.

expand-cmd-path
     Expand the current command to its full pathname.

expand-or-complete (TAB) (unbound) (TAB)
     Attempt shell expansion on the current word. If that fails, attempt completion.

expand-or-complete-prefix
     Attempt shell expansion on the current word up to cursor.

expand-history (ESC-space ESC-!) (unbound) (unbound)
     Perform history expansion on the edit buffer.

expand-word (^X*) (unbound) (unbound)
     Attempt shell expansion on the current word.

list-choices (ESC-^D) (^D =) (^D)
     List possible completions for the current word.

list-expand (^Xg ^XG) (^G) (^G)
     List the expansion of the current word.

magic-space
     Perform history expansion and insert a space into the buffer.  This is intended to be bound to space.

menu-complete
     Like complete-word, except that menu completion is used. See the MENU_COMPLETE option.

menu-expand-or-complete
     Like expand-or-complete, except that menu completion is used.

reverse-menu-complete
     Perform menu completion, like menu-complete, except that if a menu completion is already in progress, move to the previous completion rather than the next.

Miscellaneous
-------------

accept-and-hold (ESC-A ESC-a) (unbound) (unbound)
     Push the contents of the buffer on the buffer stack and execute it.

accept-and-infer-next-history
     Execute the contents of the buffer. Then search the history list for a line matching the current one and push the event following onto the buffer stack.

accept-line (^J ^M) (^J ^M) (^J ^M)
     Finish editing the buffer.  Normally this causes the buffer to be executed as a shell command.

accept-line-and-down-history (^O) (unbound) (unbound)
     Execute the current line, and push the next history event on the the buffer stack.

vi-cmd-mode (^X^V) (unbound) (^[)
     Enter command mode; that is, select the `vicmd' keymap. Yes, this is bound by default in emacs mode.

vi-caps-lock-panic
     Hang until any lowercase key is pressed. This is for vi users without the mental capacity to keep track of their caps lock key (like the author).

clear-screen (^L ESC-^L) (^L) (^L)
     Clear the screen and redraw the prompt.

describe-key-briefly
     Reads a key sequence, then prints the function bound to that sequence.

exchange-point-and-mark (^X^X) (unbound) (unbound)
     Exchange the cursor position with the position of the mark.

execute-named-cmd (ESC-x) (unbound) (unbound)
     Read the name of an editor command and execute it.  A restricted set of editing functions is available in the mini-buffer.  An interrupt signal, as defined by the stty setting, will abort the function. The allowed functions are: backward-delete-char, vi-backward-delete-char, clear-screen, redisplay, quoted-insert, vi-quoted-insert, backward-kill-word, vi-backward-kill-word, kill-whole-line, vi-kill-line, backward-kill-line, list-choices, delete-char-or-list, complete-word, accept-line, expand-or-complete and expand-or-complete-prefix.

     kill-region kills the last word, and vi-cmd-mode is treated the same as accept-line. The space and tab characters, if not bound to one of these functions, will complete the name and then list the possibilities if the AUTO_LIST option is set. Any other character that is not bound to self-insert or self-insert-unmeta will beep and be ignored. The bindings of the current insert mode will be used.

execute-last-named-cmd (ESC-z) (unbound) (unbound)
     Redo the last function executed with execute-named-cmd.

get-line (ESC-G ESC-g) (unbound) (unbound)
     Pop the top line off the buffer stack and insert it at the cursor position.

pound-insert (unbound) (#) (unbound)
     If there is no # character at the beginning of the buffer, add one to the beginning of each line. If there is one, remove a # from each line that has one. In either case, accept the current line. The INTERACTIVE_COMMENTS option must be set for this to have any usefulness.

vi-pound-insert
     If there is no # character at the beginning of the current line, add one.  If there is one, remove it. The INTERACTIVE_COMMENTS option must be set for this to have any usefulness.

push-input
     Push the entire current multiline construct onto the buffer stack and return to the top-level (PS1) prompt. If the current parser construct is only a single line, this is exactly like push-line. Next time the editor starts up or is popped with get-line, the construct will be popped off the top of the buffer stack and loaded into the editing buffer.

push-line (^Q ESC-Q ESC-q) (unbound) (unbound)
     Push the current buffer onto the buffer stack and clear the buffer. Next time the editor starts up, the buffer will be popped off the top of the buffer stack and loaded into the editing buffer.

push-line-or-edit
     At the top-level (PS1) prompt, equivalent to push-line. At a secondary (PS2) prompt, move the entire current multiline construct into the editor buffer. The latter is equivalent to push-input followed by get-line.

redisplay (unbound) (^R) (^R)
     Redisplays the edit buffer.

send-break (^G ESC-^G) (unbound) (unbound)
     Abort the current editor function, e.g. execute-named-command, or the editor itself, e.g. if you are in vared. Otherwise abort the parsing of the current line.

run-help (ESC-H ESC-h) (unbound) (unbound)
     Push the buffer onto the buffer stack, and execute the command `run-help CMD', where CMD is the current command.  run-help is normally aliased to MAN.

vi-set-buffer (unbound) (") (unbound)
     Specify a buffer to be used in the following command. There are 35 buffers that can be specified: the 26 `named' buffers "a to "z and the nine `queued' buffers "1 to "9.  The named buffers can also be specified as "A to "Z.

     When a buffer is specified for a cut command, the text being cut replaces the previous contents of the specified buffer.  If a named buffer is specified using a capital, the newly cut text is appended to the buffer instead of overwriting it.

     If no buffer is specified for a cut command, "1 is used, and the contents of "1 to "8 are each shifted along one buffer; the contents of "9 is lost.

vi-set-mark (unbound) (m) (unbound)
     Set the specified mark at the cursor position.

set-mark-command (^@) (unbound) (unbound)
     Set the mark at the cursor position.

spell-word (ESC-$ ESC-S ESC-s) (unbound) (unbound)
     Attempt spelling correction on the current word.

undefined-key
     This command is executed when a key sequence that is not bound to any command is typed.  By default it beeps.

undo (^_ ^Xu ^X^U) (unbound) (unbound)
     Incrementally undo the last text modification.

redo
     Incrementally redo undone text modifications.

vi-undo-change (unbound) (u) (unbound)
     Undo the last text modification. If repeated, redo the modification.

what-cursor-position (^X=) (unbound) (unbound)
     Print the character under the cursor, its code as an octal, decimal and hexadecimal number, the current cursor position within the buffer and the column of the cursor in the current line.

where-is
     Read the name of an editor command and and print the listing of key sequences that invoke the specified command.

which-command (ESC-?) (unbound) (unbound)
     Push the buffer onto the buffer stack, and execute the command `which-command CMD'. where CMD is the current command.  which-command is normally aliased to WHENCE.

vi-digit-or-beginning-of-line (unbound) (0) (unbound)
     If the last command executed was a digit as part of an argument, continue the argument.  Otherwise, execute vi-beginning-of-line.

Programmable Completion
***********************

Description
===========

compctl [ -CDT ] OPTIONS [ COMMAND ... ]

compctl [ -CDT ] OPTIONS [ -x PATTERN OPTIONS - ... -- ] [ + OPTIONS [ -x ... -- ] ... [+] ] [ COMMAND ... ]

compctl -L [ -CDT ] [ COMMAND ... ]

compctl + COMMAND ...

Control the editor's completion behavior according to the supplied set of OPTIONS.  Various editing commands, notably expand-or-complete-word, usually bound to tab, will attempt to complete a word typed by the user, while others, notably delete-char-or-list, usually bound to ^D in EMACS editing mode, list the possibilities; compctl controls what those possibilities are.  They may for example be filenames (the most common case, and hence the default), shell variables, or words from a user-specified list.

Command Flags
=============

Completion of the arguments of a command may be different for each command or may use the default.  The behavior when completing the command word itself may also be separately specified.  These correspond to the following flags and arguments, all of which (except for -L) may be combined with any combination of the OPTIONS described subsequently in Option Flags:

COMMAND ...
     controls completion for the named commands, which must be listed last on the command line.  If completion is attempted for a command with a pathname containing slashes and no completion definition is found, the search is retried with the last pathname component.  Note that aliases are expanded before the command name is determined unless the COMPLETE_ALIASES option is set.  Commands should not be combined with the -C, -D or -T flags.

-C
     controls completion when the command word itself is being completed. If no compctl -C command has been issued,  the names of any executable command (whether in the path or specific to the shell, such as aliases or functions) are completed.

-D
     controls default completion behavior for the arguments of commands not assigned any special behavior.  If no compctl -D command has been issued, filenames are completed.

-T
     supplies completion flags to be used before any other processing is done, even those given to specific commands with other compctl definitions.  This is only useful when combined with extended completion (the -x flag, see Extended Completion below). Using this flag you can define default behavior which will apply to all commands without exception, or you can alter the standard behavior for all commands.  For example, if your access to the user database is too slow and/or it contains too many users (so that completion after `~' is too slow to be usable), you can use

     compctl -Tx  'C[0,*/*]' -f - 's[~]' -k friends -S/

     to complete the strings in the array friends after a `~'. The first argument is necessary so that this form of ~-completion is not tried after the directory name is finished.

-L
     lists the existing completion behavior in a manner suitable for putting into a start-up script; the existing behavior is not changed. Any combination of the above forms may be specified, otherwise all defined completions are listed.  Any other flags supplied are ignored.

no argument
     If no argument is given, compctl lists all defined completions in an abbreviated form;  with a list of OPTIONS, all completions with those flags set (not counting extended completion) are listed.

If the + flag is alone and followed immediately by the COMMAND list, the completion behavior for all the commands in the list is reset to the default.  In other words, completion will subsequently use the options specified by the -D flag.

Option Flags
============

[ -fcFBdeaRGovNAIOPZEnbjrzu/ ]

[ -k ARRAY ] [ -g GLOBSTRING ] [ -s SUBSTSTRING ]

[ -K FUNCTION ] [ -H NUM PATTERN ]

[ -Q ] [ -P PREFIX ] [ -S SUFFIX ]

[ -W FILE-PREFIX ]

[ -q ] [ -X EXPLANATION ] [ -Y EXPLANATION ]

[ -y FUNC-OR-VAR ] [ -l CMD ] [ -U ]

The remaining OPTIONS specify the type of command arguments to look for during completion.  Any combination of these flags may be specified; the result is a sorted list of all the possibilities.  The options are as follows.

Simple Flags
------------

These produce completion lists made up by the shell itself:

-f
     Filenames and filesystem paths.

-/
     Just filesystem paths.

-c
     Command names, including aliases, shell functions, builtins and reserved words.

-F
     Function names.

-B
     Names of builtin commands.

-m
     Names of external commands.

-w
     Reserved words.

-a
     Alias names.

-R
     Names of regular (non-global) aliases.

-G
     Names of global aliases.

-d
     This can be combined with -F, -B, -w, -a, -R and -G to get names of disabled functions, builtins, reserved words or aliases.

-e
     This option (to show enabled commands) is in effect by default, but may be combined with -d; -de in combination with -F, -B, -w, -a, -R and -G will complete names of functions, builtins, reserved words or aliases whether or not they are disabled.

-o
     Names of shell options (see Options).

-v
     Names of any variable defined in the shell.

-N
     Names of scalar (non-array) parameters.

-A
     Array names.

-I
     Names of integer variables.

-O
     Names of read-only variables.

-p
     Names of parameters used by the shell (including special parameters).

-Z
     Names of shell special parameters.

-E
     Names of environment variables.

-n
     Named directories.

-b
     Key binding names.

-j
     Job names:  the first word of the job leader's command line.  This is useful with the kill builtin.

-r
     Names of running jobs.

-z
     Names of suspended jobs.

-u
     User names.

Flags with Arguments
--------------------

These have user supplied arguments to determine how the list of completions is to be made up:

-k ARRAY
     Names taken from the elements of $ARRAY (note that the `$' does not appear on the command line). Alternatively, the argument ARRAY itself may be a set of space- or comma-separated values in parentheses, in which any delimiter may be escaped with a backslash; in this case the argument should be quoted.  For example,

     compctl -k "(cputime filesize datasize stacksize

     coredumpsize resident descriptors)" limit

-g GLOBSTRING
     The GLOBSTRING is expanded using filename globbing; it should be quoted to protect it from immediate expansion. The resulting filenames are taken as the possible completions.  Use `*(/)' instead of `*/' for directories.  The fignore special parameter is not applied to the resulting files.  More than one pattern may be given separated by blanks. (Note that brace expansion is not part of globbing.  Use the syntax `(either|or)' to match alternatives.)

-s SUBSTSTRING
     The SUBSTSTRING is split into words and these words are than expanded using all shell expansion mechanisms (see Expansion).  The resulting words are taken as possible completions.  The fignore special parameter is not applied to the resulting files.  Note that -g is faster for filenames.

-K FUNCTION
     Call the given function to get the completions.  The function is passed two arguments: the prefix and the suffix of the word on which completion is to be attempted, in other words those characters before the cursor position, and those from the cursor position onwards.  The whole command line can be accessed with the -c and -l flags of the read builtin.  The function should set the variable reply to an array containing the completions (one completion per element); note that reply should not be made local to the function.  From such a function the command line can be accessed with the -c and -l flags to the read builtin.  For example,

     function whoson { reply=(`users`); }

     compctl -K whoson talk

     completes only logged-on users after `talk'.  Note that `whoson' must return an array, so `reply=`users`' would be incorrect.

-H NUM PATTERN
     The possible completions are taken from the last NUM history lines.  Only words matching PATTERN are taken.  If NUM is zero or negative the whole history is searched and if PATTERN is the empty string all words are taken (as with `*').  A typical use is

     compctl -D -f + -H 0

     which forces completion to look back in the history list for a word if no filename matches.

Control Flags
-------------

These do not directly specify types of name to be completed, but manipulate the options that do:

-Q
     This instructs the shell not to quote any metacharacters in the possible completions.  Normally the results of a completion are inserted into the command line with any metacharacters quoted so that they are interpreted as normal characters.  This is appropriate for filenames and ordinary strings.  However, for special effects, such as inserting a backquoted expression from a completion array (-k) so that the expression will not be evaluated until the complete line is executed, this option must be used.

-P PREFIX
     The PREFIX is inserted just before the completed string; any initial part already typed will be completed and the whole PREFIX ignored for completion purposes.  For example,

     compctl -j -P "%" kill

     inserts a `%' after the kill command and then completes job names.

-S SUFFIX
     When a completion is found the SUFFIX is inserted after the completed string.  In the case of menu completion the suffix is inserted immediately, but it is still possible to cycle through the list of completions by repeatedly hitting the same key.

-W FILE-PREFIX
     With directory FILE-PREFIX:  for command, file, directory and globbing completion (options -c, -f, -/, -g), the file prefix is implicitly added in front of the completion.  For example,

     compctl -/ -W ~/Mail maildirs

     completes any subdirectories to any depth beneath the directory ~/Mail, although that prefix does not appear on the command line.

-q
     If used with a suffix as specified by the -S option, this causes the suffix to be removed if the next character typed is a blank or does not insert anything (the same rule as used for the AUTO_REMOVE_SLASH option).  The option is most useful for list separators (comma, colon, etc.).

-l CMD
     This option cannot be combined with any other.  It restricts the range of command line words that are considered to be arguments.  If combined with one of the extended completion patterns `p[...]', `r[...]', or `R[...]'  (see Extended Completion below) the range is restricted to the range of arguments specified in the brackets.  Completion is then performed as if these had been given as arguments to the CMD supplied with the option. If the CMD string is empty the first word in the range is instead taken as the command name, and command name completion performed on the first word in the range.  For example,

     compctl -x 'r[-exec,;]' -l  -- find

     completes arguments between `-exec' and the following `;' (or the end of the command line if there is no such string) as if they were a separate command line.

-U
     Use the whole list of possible completions, whether or not they actually match the word on the command line.  The word typed so far will be deleted.  This is most useful with a function (given by the -K option) which can examine the word components passed to it (or via the read builtin's -c and -l flags) and use its own criteria to decide what matches.  If there is no completion, the original word is retained.

-y FUNC-OR-VAR
     The list provided by FUNC-OR-VAR is displayed instead of the list of completions whenever a listing is required; the actual completions to be inserted are not affected.  It can be provided in two ways. Firstly, if FUNC-OR-VAR begins with a $ it defines a variable, or if it begins with a left parenthesis a literal array, which contains the list.  A variable may have been set by a call to a function using the -K option.  Otherwise it contains the name of a function which will be executed to create the list.  The function will be passed as an argument list all matching completions, including prefixes and suffixes expanded in full, and should set the array REPLY to the result.  In both cases, the display list will only be retrieved after a complete list of matches has been created.

     Note that the returned list does not have to correspond, even in length, to the original set of matches, and may be passed as a scalar instead of an array.  No special formatting of characters is performed on the output in this case; in particular, newlines are printed literally and if they appear output in columns is suppressed.

-X EXPLANATION
     Print EXPLANATION when trying completion on the current set of options. A `%n' in this string is replaced by the number of matches. The explanation only appears if completion was tried and there was no unique match, or when listing completions.

-Y EXPLANATION
     Identical to -X, except that the EXPLANATION first undergoes expansion following the usual rules for strings in double quotes. The expansion will be carried out after any functions are called for the -K or -y options, allowing them to set variables.

Alternative Completion
======================

compctl [ -CDT ] OPTIONS + OPTIONS [ + ... ] [ + ] COMMAND ...

The form with `+' specifies alternative options. Completion is tried with the options before the first `+'. If this produces no matches completion is tried with the flags after the `+' and so on. If there are no flags after the last `+' and a match has not been found up to that point, default completion is tried.

Extended Completion
===================

compctl [ -CDT ] OPTIONS -x PATTERN OPTIONS - ... -- [ COMMAND ... ]

compctl [ -CDT ] OPTIONS [ -x PATTERN OPTIONS - ... -- ] [ + OPTIONS [ -x ... -- ] ... [+] ] [ COMMAND ... ]

The form with `-x' specifies extended completion for the commands given; as shown, it may be combined with alternative completion using `+'.  Each PATTERN is examined in turn; when a match is found, the corresponding OPTIONS, as described in Option Flags above, are used to generate possible completions.  If no PATTERN matches, the OPTIONS given before the -x are used.

Note that each pattern should be supplied as a single argument and should be quoted to prevent expansion of metacharacters by the shell.

A PATTERN is built of sub-patterns separated by commas; it matches if at least one of these sub-patterns matches (they are `or'ed). These sub-patterns are in turn composed of other sub-patterns separated by white spaces which match if all of the sub-patterns match (they are `and'ed).  An element of the sub-patterns is of the form `C[...][...]', where the pairs of brackets may be repeated as often as necessary, and matches if any of the sets of brackets match (an `or').  The example below makes this clearer.

The elements may be any of the following:

s[STRING]...
     Matches if the current word on the command line starts with one of the strings given in brackets.  The STRING is not removed and is not part of the completion.

S[STRING]...
     Like s[STRING] except that the STRING is part of the completion.

p[FROM,TO]...
     Matches if the number of the current word is between one of the FROM and TO pairs inclusive. The comma and TO are optional; TO defaults to the same value as FROM.  The numbers may be negative: -N refers to the N'th last word on the line.

c[OFFSET,STRING]...
     Matches if the STRING matches the word offset by OFFSET from the current word position.  Usually OFFSET will be negative.

C[OFFSET,PATTERN]...
     Like c but using pattern matching instead.

w[INDEX,STRING]...
     Matches if the word in position INDEX is equal to the corresponding STRING.  Note that the word count is made after any alias expansion.

W[INDEX,PATTERN]...
     Like w but using pattern matching instead.

n[INDEX,STRING]...
     Matches if the current word contains STRING.  Anything up to and including the INDEXth occurrence of this string will not be considered part of the completion, but the rest will.  INDEX may be negative to count from the end: in most cases, INDEX will be 1 or -1.  For example,

     compctl -s '`users`' -x 'n[1,@]' -k hosts -- talk

     will usually complete usernames, but if you insert an @ after the name, names from the array HOSTS (assumed to contain hostnames, though you must make the array yourself) will be completed.  Other commands such as rcp can be handled similarly.

N[INDEX,STRING]...
     Like n except that the string will be taken as a character class.  Anything up to and including the INDEXth occurrence of any of the characters in STRING will not be considered part of the completion.

m[MIN,MAX]...
     Matches if the total number of words lies between MIN and MAX inclusive.

r[STR1,STR2]...
     Matches if the cursor is after a word with prefix STR1.  If there is also a word with prefix STR2 on the command line it matches only if the cursor is before this word.

R[STR1,STR2]...
     Like r but using pattern matching instead.

Example
=======

compctl -u -x 's[+] c[-1,-f],s[-f+]' -g '~/Mail/*(:t)' \

- 's[-f],c[-1,-f]' -f -- mail

This is to be interpreted as follows:

If the current command is mail, then

if ((the current word begins with + and the previous word is -f) or (the current word begins with -f+)), then complete the non-directory part (the `:t' glob modifier) of files in the directory ~/Mail; else

if the current word begins with -f or the previous word was -f, then complete any file; else

complete user names.

Zsh Modules
***********

Description
===========

Some optional parts of zsh are in modules, separate from the core of the shell.  Each of these modules may be linked in to the shell at build time, or can be dynamically linked while the shell is running if the installation supports this feature.  The modules available are:

cap
     Builtins for manipulating POSIX.1e (POSIX.6) capability (privilege) sets.

clone
     A builtin that can clone a running shell onto another terminal.

comp1
     Base of the completion system.  Used by the compctl and zle modules.

compctl
     The compctl builtin for controlling completion.

deltochar
     A ZLE function duplicating EMACS' zap-to-char.

example
     An example of how to write a module.

files
     Some basic file manipulation commands as builtins.

sched
     A builtin that provides a timed execution facility within the shell.

stat
     A builtin command interface to the stat system call.

zle
     The Zsh Line Editor, including the bindkey and vared builtins.

The cap Module
==============

The cap module is used for manipulating POSIX.1e (POSIX.6) capability sets.  If the operating system does not support this interface, the builtins defined by this module will do nothing. The builtins in this module are:

cap [ CAPABILITIES ]
     Change the shell's process capability sets to the specified CAPABILITIES, otherwise display the shell's current capabilities.

getcap FILENAME ...
     This is a built-in implementation of the POSIX standard utility.  It displays the capability sets on each specified FILENAME.

setcap CAPABILITIES FILENAME ...
     This is a built-in implementation of the POSIX standard utility.  It sets the capability sets on each specified FILENAME to the specified CAPABILITIES.

The clone Module
================

The clone module makes available one builtin command:

clone TTY
     Creates a forked instance of the current shell, attached to the specified TTY.  In the new shell, the PID, PPID and TTY special parameters are changed appropriately.  $! is set to zero in the new shell, and to the new shell's PID in the original shell.

     The return value of the builtin is zero in both shells if successful, and non-zero on error.

The comp1 Module
================

The comp1 module does nothing that is visible to the user. Its purpose is to provide the internal basis of the programmable completion mechanism.

This module must be loaded before any module that provides a means of controlling completion (such as the compctl module), or that uses completions (such as the zle module). This is done automatically for modules distributed with zsh, and for other modules can be effected by the use of zmodload -d.

The compctl Module
==================

The compctl module makes available one builtin command, compctl, which is the standard way to control completions for ZLE.  See Programmable Completion.

The deltochar Module
====================

The deltochar module makes available one ZLE function:

delete-to-char
     Read a character from the keyboard, and delete from the cursor position up to and including the next (or, with repeat count N, the Nth) instance of that character.

The example Module
==================

The example module makes available one builtin command:

example [ -flags ] [ ARGS ... ]
     Displays the flags and arguments it is invoked with.

The purpose of the module is to serve as an example of how to write a module.

The files Module
================

The files module makes some standard commands available as builtins:

ln [ -dfis ] FILENAME DEST
ln [ -dfis ] FILENAME ... DIR
     Creates hard (or, with -s, symbolic) links.  In the first form, the specified DESTination is created, as a link to the specified FILENAME.  In the second form, each of the FILENAMEs is taken in turn, and linked to a pathname in the specified DIRectory that has the same last pathname component.

     Normally, ln will not attempt to create hard links to directories.  This check can be overridden using the -d option. Typically only the super-user can actually succeed in creating hard links to directories. This does not apply to symbolic links in any case.

     By default, existing files cannot be replaced by links. The -i option causes the user to be queried about replacing existing files.  The -f option causes existing files to be silently deleted, without querying.  -f takes precedence.

mkdir [ -p ] [ -m MODE ] DIR ...
     Creates directories.  With the -p option, non-existing parent directories are first created if necessary, and there will be no complaint if the directory already exists. The -m option can be used to specify (in octal) a set of file permissions for the created directories, otherwise mode 777 modified by the current umask (see man page umask(2)) is used.

mv [ -fi ] FILENAME DEST
mv [ -fi ] FILENAME ... DIR
     Moves files.  In the first form, the specified FILENAME is moved to the specified DESTination.  In the second form, each of the FILENAMEs is taken in turn, and moved to a pathname in the specified DIRectory that has the same last pathname component.

     By default, the user will be queried before replacing any file that the user cannot write to, but writable files will be silently removed. The -i option causes the user to be queried about replacing any existing files.  The -f option causes any existing files to be silently deleted, without querying.  -f takes precedence.

     Note that this mv will not move files across devices. Historical versions of mv, when actual renaming is impossible, fall back on copying and removing files; if this behaviour is desired, use cp and rm manually.  This may change in a future version.

rm [ -dfirs ] FILENAME ...
     Removes files and directories specified.

     Normally, rm will not remove directories (except with the -r option).  The -d option causes rm to try removing directories with unlink (see man page unlink(2)), the same method used for files. Typically only the super-user can actually succeed in unlinking directories in this way. -d takes precedence over -r.

     By default, the user will be queried before removing any file that the user cannot write to, but writable files will be silently removed. The -i option causes the user to be queried about removing any files.  The -f option causes files to be silently deleted, without querying, and suppresses all error indications. -f takes precedence.

     The -r option causes rm to recursively descend into directories, deleting all files in the directory before removing the directory with the rmdir system call (see man page rmdir(2)).

     The -s option is a zsh extension to rm functionality.  It enables paranoid behaviour, intended to avoid common security problems involving a root-run rm being tricked into removing files other than the ones intended.  It will refuse to follow symbolic links, so that (for example) ``rm /tmp/foo/passwd can't accidentally remove /etc/passwd if /tmp/foo happens to be a link to /etc.  It will also check where it is after leaving directories, so that a recursive removal of a deep directory tree can't end up recursively removing /usr as a result of directories being moved up the tree.

rmdir DIR ...
     Removes empty directories specified.

sync
     Calls the system call of the same name (see man page sync(2)), which flushes dirty buffers to disk.  It might return before the I/O has actually been completed.

The sched Module
================

The sched module makes available one builtin command:

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 relative time. With no arguments, prints the list of scheduled commands. With the argument `-ITEM', removes the given item from the list.

The stat Module
===============

The stat module makes available one builtin command:

stat [ -gnNlLtTrs ] [ -f FD ] [ -A ARRAY ] [ -F FMT ] [ +ELEMENT ] [ FILE ... ]
     The command acts as a front end to the stat system call (see man page stat(2)). If the stat call fails, the appropriate system error message printed and status 1 is returned. The fields of struct stat give information about the files provided as arguments to the command.  In addition to those available from the stat call, an extra element `link' is provided. These elements are:

     device
          The number of the device on which the file resides.

     inode
          The unique number of the file on this device (`inode' number).

     mode
          The mode of the file; that is, the file's type and access permissions. With the -s option, this will be returned as a string corresponding to the first column in the display of the ls -l command.

     nlink
          The number of hard links to the file.

     uid
          The user ID of the owner of the file.  With the -s option, this is displayed as a user name.

     gid
          The group ID of the file.  With the -s option, this is displayed as a group name.

     rdev
          The raw device number.  This is only useful for special devices.

     size
          The size of the file in bytes.

     atime
     mtime
     ctime
          The last access, modification and inode change times of the file, respectively, as the number of seconds since midnight GMT on 1st January, 1970.  With the -s option, these are printed as strings for the local time zone; the format can be altered with the -F option, and with the -g option the times are in GMT.

     blksize
          The number of bytes in one allocation block on the device on which the file resides.

     block
          The number of disk blocks used by the file.

     link
          If the file is a link and the -L option is in effect, this contains the name of the file linked to, otherwise it is empty.  Note that if this element is selected (``stat +link) then the -L option is automatically used.

     A particular element may be selected by including its name preceded by a `+' in the option list; only one element is allowed. The element may be shortened to any unique set of leading characters.  Otherwise, all elements will be shown for all files.

     Options:

     -A ARRAY
          Instead of displaying the results on standard output, assign them to an ARRAY, one struct stat element per array element for each file in order.  In this case neither the name of the element nor the name of the files is provided unless the -t or -n options are provided, respectively.  In the former case the element name appears as a prefix to the appropriate array element and in the latter case the file name appears as a separate array element preceding all the others. Other formatting options are respected.

     -f FD
          Use the file on file descriptor FD instead of named files; no list of file names is allowed in this case.

     -F FMT
          Supplies a strftime (see man page strftime(3)) string for the formatting of the time elements.  The -s option is implied.

     -g
          Show the time elements in the GMT time zone.  The -s option is implied.

     -l
          List the names of the type elements (to standard output or an array as appropriate) and return immediately; options other than -A and arguments are ignored.

     -L
          Perform an lstat (see man page lstat(2)) rather than a stat system call.  In this case, if the file is a link, information about the link itself rather than the target file is returned. This option is required to make the link element useful.

     -n
          Always show the names of files.  Usually these are only shown when output is to standard output and there is more than one file in the list.

     -N
          Never show the names of files.

     -r
          Print raw data (the default format) alongside string data (the -s format); the string data appears in parentheses after the raw data.

     -s
          Print mode, uid, gid and the three time elements as strings instead of numbers.  In each case the format is like that of ls -l.

     -t
          Always show the type names for the elements of struct stat.  Usually these are only shown when output is to standard output and no individual element has been selected.

     -T
          Never show the type names of the struct stat elements.

The zle Module
==============

The zle module contains the Zsh Line Editor.  See Zsh Line Editor.  It also contains three related builtin commands:

bindkey [ OPTIONS ] -l
bindkey [ OPTIONS ] -d
bindkey [ OPTIONS ] -D KEYMAP ...
bindkey [ OPTIONS ] -A OLD-KEYMAP NEW-KEYMAP
bindkey [ OPTIONS ] -N NEW-KEYMAP [ OLD-KEYMAP ]
bindkey [ OPTIONS ] -m
bindkey [ OPTIONS ] -r IN-STRING ...
bindkey [ OPTIONS ] -s IN-STRING OUT-STRING ...
bindkey [ OPTIONS ] IN-STRING COMMAND ...
bindkey [ OPTIONS ] [ IN-STRING ]
     bindkey's options can be divided into three categories: keymap selection, operation selection, and others.  The keymap selection options are:

     -e
          Selects keymap `emacs', and also links it to `main'.

     -v
          Selects keymap `viins', and also links it to `main'.

     -a
          Selects keymap `vicmd'.

     -M
          The first non-option argument is used as a keymap name, and does not otherwise count as an argument.

     Some operations do not permit a keymap to be selected. If a keymap selection is required and none of the options above are used, the `main' keymap is used.  These operations do not permit a keymap to be selected:

     -l
          List all existing keymap names.  If the -L option is used, list in the form of bindkey commands to create the keymaps.

     -d
          Delete all existing keymaps and reset to the default state.

     -D KEYMAP ...
          Delete the named KEYMAPs.

     -A OLD-KEYMAP NEW-KEYMAP
          Make the NEW-KEYMAP name an alias for OLD-KEYMAP, so that both names refer to the same keymap.  The names have equal standing; if either is deleted, the other remains.  If there is already a keymap with the NEW-KEYMAP name, it is deleted.

     -N NEW-KEYMAP [ OLD-KEYMAP ]
          Create a new keymap, named NEW-KEYMAP.  If a keymap already has that name, it is deleted.  If an OLD-KEYMAP name is given, the new keymap is initialised to be a duplicate of it, otherwise the new keymap will be empty.

     The following operations require a keymap to be selected:

     -m
          Add the built-in set of meta-key bindings to the selected keymap. Only keys that are unbound or bound to self-insert are affected.

     -r IN-STRING ...
          Unbind the specified IN-STRINGs in the selected keymap. This is exactly equivalent to binding the strings to undefined-key.

     -s IN-STRING OUT-STRING ...
          Bind each IN-STRING to each OUT-STRING. When IN-STRING is typed, OUT-STRING will be pushed back and treated as input to the line editor.

     IN-STRING COMMAND ...
          Bind each IN-STRING to each COMMAND.

     [ IN-STRING ]
          List key bindings.  If an IN-STRING is specified, the binding of that string in the selected keymap is displayed.  Otherwise, all key bindings in the selected keymap are displayed.  As an exception, if the -e or -v options are used alone, the keymap is not displayed - the implicit linking of keymaps is the only thing that happens.

     In the binding operations, if the -R option is used, the IN-STRINGs are interpreted as ranges, instead of plain strings.  A valid range consists of two characters, with an optional `-' between them.  All characters between the two specified, inclusive, are bound as specified.

     For either IN-STRING or OUT-STRING, the following escape sequences are recognised:

     \a
          bell character

     \b
          backspace

     \e, \E
          escape

     \f
          form feed

     \n
          linefeed (newline)

     \r
          carriage return

     \t
          horizontal tab

     \v
          vertical tab

     \NNN
          character code in octal

     \xNN
          character code in hexadecimal

     \M[-]X
          character with meta bit set

     \C[-]X
          control character

     ^X
          control character

     In all other cases, `\' escapes the following character.  Delete is written as `^?'.  Note that `\M^?' and `^\M?' are not the same.

vared [ -ch ] [ -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 exits, 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 already exist. If the -p flag is given, the following string will be taken as the prompt to display at the left.  If the -r flag is given, the following string gives the prompt to display at the right.  If the -h flag is specified, the history can be accessed from ZLE.

zle -l [ -L ]
zle -D WIDGET ...
zle -A OLD-WIDGET NEW-WIDGET
zle -N WIDGET [ FUNCTION ]
zle WIDGET
     The zle builtin performs a number of different actions concerning ZLE.  Which operation it performs depends on its options:

     -l [ -L ]
          List all existing user-defined widgets.  If the -L option is used, list in the form of zle commands to create the widgets. Built-in widgets are not listed.

     -D WIDGET ...
          Delete the named WIDGETs.

     -A OLD-WIDGET NEW-WIDGET
          Make the NEW-WIDGET name an alias for OLD-WIDGET, so that both names refer to the same widget.  The names have equal standing; if either is deleted, the other remains.  If there is already a widget with the NEW-WIDGET name, it is deleted.

     -N WIDGET [ FUNCTION ]
          Create a user-defined widget.  If there is already a widget with the specified name, it is overwritten.  When the new widget is invoked from within the editor, the specified shell FUNCTION is called.  If no function name is specified, it defaults to the same name as the widget.

     WIDGET
          Invoke the specified widget.  This can only be done when ZLE is active; normally this will be within a user-defined widget.