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ZSHCOMPSYS(1) General Commands Manual ZSHCOMPSYS(1)

NAME
zshcompsys - zsh completion system

DESCRIPTION
This describes the shell code for the `new' completion system, referred to as compsys. It is
written in shell functions based on the features described in zshcompwid(1).

The features are contextual, sensitive to the point at which completion is started. Many
completions are already provided. For this reason, a user can perform a great many tasks
without knowing any details beyond how to initialize the system, which is described below in
INITIALIZATION.

The context that decides what completion is to be performed may be
• an argument or option position: these describe the position on the command line at
which completion is requested. For example `first argument to rmdir, the word being
completed names a directory';

• a special context, denoting an element in the shell's syntax. For example `a word in
command position' or `an array subscript'.

A full context specification contains other elements, as we shall describe.

Besides commands names and contexts, the system employs two more concepts, styles and tags.
These provide ways for the user to configure the system's behaviour.

Tags play a dual role. They serve as a classification system for the matches, typically in‐
dicating a class of object that the user may need to distinguish. For example, when complet‐
ing arguments of the ls command the user may prefer to try files before directories, so both
of these are tags. They also appear as the rightmost element in a context specification.

Styles modify various operations of the completion system, such as output formatting, but
also what kinds of completers are used (and in what order), or which tags are examined.
Styles may accept arguments and are manipulated using the zstyle command described in see
zshmodules(1).

In summary, tags describe what the completion objects are, and style how they are to be com‐
pleted. At various points of execution, the completion system checks what styles and/or tags
are defined for the current context, and uses that to modify its behavior. The full descrip‐
tion of context handling, which determines how tags and other elements of the context influ‐
ence the behaviour of styles, is described below in COMPLETION SYSTEM CONFIGURATION.

When a completion is requested, a dispatcher function is called; see the description of
_main_complete in the list of control functions below. This dispatcher decides which function
should be called to produce the completions, and calls it. The result is passed to one or
more completers, functions that implement individual completion strategies: simple comple‐
tion, error correction, completion with error correction, menu selection, etc.

More generally, the shell functions contained in the completion system are of two types:
• those beginning `comp' are to be called directly; there are only a few of these;

• those beginning `_' are called by the completion code. The shell functions of this
set, which implement completion behaviour and may be bound to keystrokes, are referred
to as `widgets'. These proliferate as new completions are required.

INITIALIZATION
If the system was installed completely, it should be enough to call the shell function
compinit from your initialization file; see the next section. However, the function compin‐‐
stall can be run by a user to configure various aspects of the completion system.

Usually, compinstall will insert code into .zshrc, although if that is not writable it will
save it in another file and tell you that file's location. Note that it is up to you to make
sure that the lines added to .zshrc are actually run; you may, for example, need to move them
to an earlier place in the file if .zshrc usually returns early. So long as you keep them
all together (including the comment lines at the start and finish), you can rerun compinstall
and it will correctly locate and modify these lines. Note, however, that any code you add to
this section by hand is likely to be lost if you rerun compinstall, although lines using the
command `zstyle' should be gracefully handled.

The new code will take effect next time you start the shell, or run .zshrc by hand; there is
also an option to make them take effect immediately. However, if compinstall has removed
definitions, you will need to restart the shell to see the changes.

To run compinstall you will need to make sure it is in a directory mentioned in your fpath
parameter, which should already be the case if zsh was properly configured as long as your
startup files do not remove the appropriate directories from fpath. Then it must be au‐
toloaded (`autoload -U compinstall' is recommended). You can abort the installation any time
you are being prompted for information, and your .zshrc will not be altered at all; changes
only take place right at the end, where you are specifically asked for confirmation.

Use of compinit
This section describes the use of compinit to initialize completion for the current session
when called directly; if you have run compinstall it will be called automatically from your
.zshrc.

To initialize the system, the function compinit should be in a directory mentioned in the
fpath parameter, and should be autoloaded (`autoload -U compinit' is recommended), and then
run simply as `compinit'. This will define a few utility functions, arrange for all the nec‐
essary shell functions to be autoloaded, and will then re-define all widgets that do comple‐
tion to use the new system. If you use the menu-select widget, which is part of the zsh/com‐‐
plist module, you should make sure that that module is loaded before the call to compinit so
that that widget is also re-defined. If completion styles (see below) are set up to perform
expansion as well as completion by default, and the TAB key is bound to expand-or-complete,
compinit will rebind it to complete-word; this is necessary to use the correct form of expan‐
sion.

Should you need to use the original completion commands, you can still bind keys to the old
widgets by putting a `.' in front of the widget name, e.g. `.expand-or-complete'.

To speed up the running of compinit, it can be made to produce a dumped configuration that
will be read in on future invocations; this is the default, but can be turned off by calling
compinit with the option -D. The dumped file is .zcompdump in the same directory as the
startup files (i.e. $ZDOTDIR or $HOME); alternatively, an explicit file name can be given by
`compinit -d dumpfile'. The next invocation of compinit will read the dumped file instead of
performing a full initialization.

If the number of completion files changes, compinit will recognise this and produce a new
dump file. However, if the name of a function or the arguments in the first line of a #com‐‐
pdef function (as described below) change, it is easiest to delete the dump file by hand so
that compinit will re-create it the next time it is run. The check performed to see if there
are new functions can be omitted by giving the option -C. In this case the dump file will
only be created if there isn't one already.

The dumping is actually done by another function, compdump, but you will only need to run
this yourself if you change the configuration (e.g. using compdef) and then want to dump the
new one. The name of the old dumped file will be remembered for this purpose.

If the parameter _compdir is set, compinit uses it as a directory where completion functions
can be found; this is only necessary if they are not already in the function search path.

For security reasons compinit also checks if the completion system would use files not owned
by root or by the current user, or files in directories that are world- or group-writable or
that are not owned by root or by the current user. If such files or directories are found,
compinit will ask if the completion system should really be used. To avoid these tests and
make all files found be used without asking, use the option -u, and to make compinit silently
ignore all insecure files and directories use the option -i. This security check is skipped
entirely when the -C option is given.

The security check can be retried at any time by running the function compaudit. This is the
same check used by compinit, but when it is executed directly any changes to fpath are made
local to the function so they do not persist. The directories to be checked may be passed as
arguments; if none are given, compaudit uses fpath and _compdir to find completion system di‐
rectories, adding missing ones to fpath as necessary. To force a check of exactly the direc‐
tories currently named in fpath, set _compdir to an empty string before calling compaudit or
compinit.

The function bashcompinit provides compatibility with bash's programmable completion system.
When run it will define the functions, compgen and complete which correspond to the bash
builtins with the same names. It will then be possible to use completion specifications and
functions written for bash.

Autoloaded files
The convention for autoloaded functions used in completion is that they start with an under‐
score; as already mentioned, the fpath/FPATH parameter must contain the directory in which
they are stored. If zsh was properly installed on your system, then fpath/FPATH automati‐
cally contains the required directories for the standard functions.

For incomplete installations, if compinit does not find enough files beginning with an under‐
score (fewer than twenty) in the search path, it will try to find more by adding the direc‐
tory _compdir to the search path. If that directory has a subdirectory named Base, all sub‐
directories will be added to the path. Furthermore, if the subdirectory Base has a subdirec‐
tory named Core, compinit will add all subdirectories of the subdirectories to the path: this
allows the functions to be in the same format as in the zsh source distribution.

When compinit is run, it searches all such files accessible via fpath/FPATH and reads the
first line of each of them. This line should contain one of the tags described below. Files
whose first line does not start with one of these tags are not considered to be part of the
completion system and will not be treated specially.

The tags are:

#compdef name ... [ -{p|P} pattern ... [ -N name ... ] ]
The file will be made autoloadable and the function defined in it will be called when
completing names, each of which is either the name of a command whose arguments are to
be completed or one of a number of special contexts in the form -context- described
below.

Each name may also be of the form `cmd=service'. When completing the command cmd, the
function typically behaves as if the command (or special context) service was being
completed instead. This provides a way of altering the behaviour of functions that
can perform many different completions. It is implemented by setting the parameter
$service when calling the function; the function may choose to interpret this how it
wishes, and simpler functions will probably ignore it.

If the #compdef line contains one of the options -p or -P, the words following are
taken to be patterns. The function will be called when completion is attempted for a
command or context that matches one of the patterns. The options -p and -P are used
to specify patterns to be tried before or after other completions respectively. Hence
-P may be used to specify default actions.

The option -N is used after a list following -p or -P; it specifies that remaining
words no longer define patterns. It is possible to toggle between the three options
as many times as necessary.

#compdef -k style key-sequence ...
This option creates a widget behaving like the builtin widget style and binds it to
the given key-sequences, if any. The style must be one of the builtin widgets that
perform completion, namely complete-word, delete-char-or-list, expand-or-complete, ex‐‐
pand-or-complete-prefix, list-choices, menu-complete, menu-expand-or-complete, or re‐‐
verse-menu-complete. If the zsh/complist module is loaded (see zshmodules(1)) the
widget menu-select is also available.

When one of the key-sequences is typed, the function in the file will be invoked to
generate the matches. Note that a key will not be re-bound if it already was (that
is, was bound to something other than undefined-key). The widget created has the same
name as the file and can be bound to any other keys using bindkey as usual.

#compdef -K widget-name style key-sequence [ name style seq ... ]
This is similar to -k except that only one key-sequence argument may be given for each
widget-name style pair. However, the entire set of three arguments may be repeated
with a different set of arguments. Note in particular that the widget-name must be
distinct in each set. If it does not begin with `_' this will be added. The wid‐
get-name should not clash with the name of any existing widget: names based on the
name of the function are most useful. For example,

#compdef -K _foo_complete complete-word "^X^C" \
_foo_list list-choices "^X^D"

(all on one line) defines a widget _foo_complete for completion, bound to `^X^C', and
a widget _foo_list for listing, bound to `^X^D'.

#autoload [ options ]
Functions with the #autoload tag are marked for autoloading but are not otherwise
treated specially. Typically they are to be called from within one of the completion
functions. Any options supplied will be passed to the autoload builtin; a typical use
is +X to force the function to be loaded immediately. Note that the -U and -z flags
are always added implicitly.

The # is part of the tag name and no white space is allowed after it. The #compdef tags use
the compdef function described below; the main difference is that the name of the function is
supplied implicitly.

The special contexts for which completion functions can be defined are:

-array-value-
The right hand side of an array-assignment (`name=(...)')

-brace-parameter-
The name of a parameter expansion within braces (`${...}')

-assign-parameter-
The name of a parameter in an assignment, i.e. on the left hand side of an `='

-command-
A word in command position

-condition-
A word inside a condition (`[[...]]')

-default-
Any word for which no other completion is defined

-equal-
A word beginning with an equals sign

-first-
This is tried before any other completion function. The function called may set the
_compskip parameter to one of various values: all: no further completion is attempted;
a string containing the substring patterns: no pattern completion functions will be
called; a string containing default: the function for the `-default-' context will not
be called, but functions defined for commands will be.

-math- Inside mathematical contexts, such as `((...))'

-parameter-
The name of a parameter expansion (`$...')

-redirect-
The word after a redirection operator.

-subscript-
The contents of a parameter subscript.

-tilde-
After an initial tilde (`~'), but before the first slash in the word.

-value-
On the right hand side of an assignment.

Default implementations are supplied for each of these contexts. In most cases the context
-context- is implemented by a corresponding function _context, for example the context
`-tilde-' and the function `_tilde').

The contexts -redirect- and -value- allow extra context-specific information. (Internally,
this is handled by the functions for each context calling the function _dispatch.) The extra
information is added separated by commas.

For the -redirect- context, the extra information is in the form `-redirect-,op,command',
where op is the redirection operator and command is the name of the command on the line. If
there is no command on the line yet, the command field will be empty.

For the -value- context, the form is `-value-,name,command', where name is the name of the
parameter on the left hand side of the assignment. In the case of elements of an associative
array, for example `assoc=(key <TAB>', name is expanded to `name-key'. In certain special
contexts, such as completing after `make CFLAGS=', the command part gives the name of the
command, here make; otherwise it is empty.

It is not necessary to define fully specific completions as the functions provided will try
to generate completions by progressively replacing the elements with `-default-'. For exam‐
ple, when completing after `foo=<TAB>', _value will try the names `-value-,foo,' (note the
empty command part), `-value-,foo,-default-' and`-value-,-default-,-default-', in that order,
until it finds a function to handle the context.

As an example:

compdef '_files -g "*.log"' '-redirect-,2>,-default-'

completes files matching `*.log' after `2> <TAB>' for any command with no more specific han‐
dler defined.

Also:

compdef _foo -value-,-default-,-default-

specifies that _foo provides completions for the values of parameters for which no special
function has been defined. This is usually handled by the function _value itself.

The same lookup rules are used when looking up styles (as described below); for example

zstyle ':completion:*:*:-redirect-,2>,*:*' file-patterns '*.log'

is another way to make completion after `2> <TAB>' complete files matching `*.log'.

Functions
The following function is defined by compinit and may be called directly.

compdef [ -ane ] function name ... [ -{p|P} pattern ... [ -N name ...]]
compdef -d name ...
compdef -k [ -an ] function style key-sequence [ key-sequence ... ]
compdef -K [ -an ] function name style key-seq [ name style seq ... ]
The first form defines the function to call for completion in the given contexts as
described for the #compdef tag above.

Alternatively, all the arguments may have the form `cmd=service'. Here service should
already have been defined by `cmd1=service' lines in #compdef files, as described
above. The argument for cmd will be completed in the same way as service.

The function argument may alternatively be a string containing almost any shell code.
If the string contains an equal sign, the above will take precedence. The option -e
may be used to specify the first argument is to be evaluated as shell code even if it
contains an equal sign. The string will be executed using the eval builtin command to
generate completions. This provides a way of avoiding having to define a new comple‐
tion function. For example, to complete files ending in `.h' as arguments to the com‐
mand foo:

compdef '_files -g "*.h"' foo

The option -n prevents any completions already defined for the command or context from
being overwritten.

The option -d deletes any completion defined for the command or contexts listed.

The names may also contain -p, -P and -N options as described for the #compdef tag.
The effect on the argument list is identical, switching between definitions of pat‐
terns tried initially, patterns tried finally, and normal commands and contexts.

The parameter $_compskip may be set by any function defined for a pattern context. If
it is set to a value containing the substring `patterns' none of the pattern-functions
will be called; if it is set to a value containing the substring `all', no other func‐
tion will be called. Setting $_compskip in this manner is of particular utility when
using the -p option, as otherwise the dispatcher will move on to additional functions
(likely the default one) after calling the pattern-context one, which can mangle the
display of completion possibilities if not handled properly.

The form with -k defines a widget with the same name as the function that will be
called for each of the key-sequences; this is like the #compdef -k tag. The function
should generate the completions needed and will otherwise behave like the builtin wid‐
get whose name is given as the style argument. The widgets usable for this are: com‐‐
plete-word, delete-char-or-list, expand-or-complete, expand-or-complete-prefix,
list-choices, menu-complete, menu-expand-or-complete, and reverse-menu-complete, as
well as menu-select if the zsh/complist module is loaded. The option -n prevents the
key being bound if it is already to bound to something other than undefined-key.

The form with -K is similar and defines multiple widgets based on the same function,
each of which requires the set of three arguments name, style and key-sequence, where
the latter two are as for -k and the first must be a unique widget name beginning with
an underscore.

Wherever applicable, the -a option makes the function autoloadable, equivalent to au‐‐
toload -U function.

The function compdef can be used to associate existing completion functions with new com‐
mands. For example,

compdef _pids foo

uses the function _pids to complete process IDs for the command foo.

Note also the _gnu_generic function described below, which can be used to complete options
for commands that understand the `--help' option.

COMPLETION SYSTEM CONFIGURATION
This section gives a short overview of how the completion system works, and then more detail
on how users can configure how and when matches are generated.

Overview
When completion is attempted somewhere on the command line the completion system begins
building the context. The context represents everything that the shell knows about the mean‐
ing of the command line and the significance of the cursor position. This takes account of a
number of things including the command word (such as `grep' or `zsh') and options to which
the current word may be an argument (such as the `-o' option to zsh which takes a shell op‐
tion as an argument).

The context starts out very generic ("we are beginning a completion") and becomes more spe‐
cific as more is learned ("the current word is in a position that is usually a command name"
or "the current word might be a variable name" and so on). Therefore the context will vary
during the same call to the completion system.

This context information is condensed into a string consisting of multiple fields separated
by colons, referred to simply as `the context' in the remainder of the documentation. Note
that a user of the completion system rarely needs to compose a context string, unless for ex‐
ample a new function is being written to perform completion for a new command. What a user
may need to do is compose a style pattern, which is matched against a context when needed to
look up context-sensitive options that configure the completion system.

The next few paragraphs explain how a context is composed within the completion function
suite. Following that is discussion of how styles are defined. Styles determine such things
as how the matches are generated, similarly to shell options but with much more control.
They are defined with the zstyle builtin command (see zshmodules(1)).

The context string always consists of a fixed set of fields, separated by colons and with a
leading colon before the first. Fields which are not yet known are left empty, but the sur‐
rounding colons appear anyway. The fields are always in the order :completion:function:com‐
pleter:command:argument:tag. These have the following meaning:

• The literal string completion, saying that this style is used by the completion sys‐
tem. This distinguishes the context from those used by, for example, zle widgets and
ZFTP functions.

• The function, if completion is called from a named widget rather than through the nor‐
mal completion system. Typically this is blank, but it is set by special widgets such
as predict-on and the various functions in the Widget directory of the distribution to
the name of that function, often in an abbreviated form.

• The completer currently active, the name of the function without the leading under‐
score and with other underscores converted to hyphens. A `completer' is in overall
control of how completion is to be performed; `complete' is the simplest, but other
completers exist to perform related tasks such as correction, or to modify the behav‐
iour of a later completer. See the section `Control Functions' below for more infor‐
mation.

• The command or a special -context-, just at it appears following the #compdef tag or
the compdef function. Completion functions for commands that have sub-commands usu‐
ally modify this field to contain the name of the command followed by a minus sign and
the sub-command. For example, the completion function for the cvs command sets this
field to cvs-add when completing arguments to the add subcommand.

• The argument; this indicates which command line or option argument we are completing.
For command arguments this generally takes the form argument-n, where n is the number
of the argument, and for arguments to options the form option-opt-n where n is the
number of the argument to option opt. However, this is only the case if the command
line is parsed with standard UNIX-style options and arguments, so many completions do
not set this.

• The tag. As described previously, tags are used to discriminate between the types of
matches a completion function can generate in a certain context. Any completion func‐
tion may use any tag name it likes, but a list of the more common ones is given below.

The context is gradually put together as the functions are executed, starting with the main
entry point, which adds :completion: and the function element if necessary. The completer
then adds the completer element. The contextual completion adds the command and argument op‐
tions. Finally, the tag is added when the types of completion are known. For example, the
context name

:completion::complete:dvips:option-o-1:files

says that normal completion was attempted as the first argument to the option -o of the com‐
mand dvips:

dvips -o ...

and the completion function will generate filenames.

Usually completion will be tried for all possible tags in an order given by the completion
function. However, this can be altered by using the tag-order style. Completion is then re‐
stricted to the list of given tags in the given order.

The _complete_help bindable command shows all the contexts and tags available for completion
at a particular point. This provides an easy way of finding information for tag-order and
other styles. It is described in the section `Bindable Commands' below.

When looking up styles the completion system uses full context names, including the tag.
Looking up the value of a style therefore consists of two things: the context, which is
matched to the most specific (best fitting) style pattern, and the name of the style itself,
which must be matched exactly. The following examples demonstrate that style patterns may be
loosely defined for styles that apply broadly, or as tightly defined as desired for styles
that apply in narrower circumstances.

For example, many completion functions can generate matches in a simple and a verbose form
and use the verbose style to decide which form should be used. To make all such functions
use the verbose form, put

zstyle ':completion:*' verbose yes

in a startup file (probably .zshrc). This gives the verbose style the value yes in every
context inside the completion system, unless that context has a more specific definition. It
is best to avoid giving the context as `*' in case the style has some meaning outside the
completion system.

Many such general purpose styles can be configured simply by using the compinstall function.

A more specific example of the use of the verbose style is by the completion for the kill
builtin. If the style is set, the builtin lists full job texts and process command lines;
otherwise it shows the bare job numbers and PIDs. To turn the style off for this use only:

zstyle ':completion:*:*:kill:*:*' verbose no

For even more control, the style can use one of the tags `jobs' or `processes'. To turn off
verbose display only for jobs:

zstyle ':completion:*:*:kill:*:jobs' verbose no

The -e option to zstyle even allows completion function code to appear as the argument to a
style; this requires some understanding of the internals of completion functions (see see
zshcompwid(1))). For example,

zstyle -e ':completion:*' hosts 'reply=($myhosts)'

This forces the value of the hosts style to be read from the variable myhosts each time a
host name is needed; this is useful if the value of myhosts can change dynamically. For an‐
other useful example, see the example in the description of the file-list style below. This
form can be slow and should be avoided for commonly examined styles such as menu and
list-rows-first.

Note that the order in which styles are defined does not matter; the style mechanism uses the
most specific possible match for a particular style to determine the set of values. More
precisely, strings are preferred over patterns (for example, `:completion::complete:::foo' is
more specific than `:completion::complete:::*'), and longer patterns are preferred over
shorter patterns.

A good rule of thumb is that any completion style pattern that needs to include more than one
wildcard (*) and that does not end in a tag name, should include all six colons (:), possibly
surrounding additional wildcards.

Style names like those of tags are arbitrary and depend on the completion function. However,
the following two sections list some of the most common tags and styles.

Standard Tags
Some of the following are only used when looking up particular styles and do not refer to a
type of match.

accounts
used to look up the users-hosts style

all-expansions
used by the _expand completer when adding the single string containing all possible
expansions

all-files
for the names of all files (as distinct from a particular subset, see the
globbed-files tag).

arguments
for arguments to a command

arrays for names of array parameters

association-keys
for keys of associative arrays; used when completing inside a subscript to a parameter
of this type

bookmarks
when completing bookmarks (e.g. for URLs and the zftp function suite)

builtins
for names of builtin commands

characters
for single characters in arguments of commands such as stty. Also used when complet‐
ing character classes after an opening bracket

colormapids
for X colormap ids

colors for color names

commands
for names of external commands. Also used by complex commands such as cvs when com‐
pleting names subcommands.

contexts
for contexts in arguments to the zstyle builtin command

corrections
used by the _approximate and _correct completers for possible corrections

cursors
for cursor names used by X programs

default
used in some contexts to provide a way of supplying a default when more specific tags
are also valid. Note that this tag is used when only the function field of the con‐
text name is set

descriptions
used when looking up the value of the format style to generate descriptions for types
of matches

devices
for names of device special files

directories
for names of directories -- local-directories is used instead when completing argu‐
ments of cd and related builtin commands when the cdpath array is set

directory-stack
for entries in the directory stack

displays
for X display names

domains
for network domains

email-plugin
for email addresses from the `_email-plugin' backend of _email_addresses

expansions
used by the _expand completer for individual words (as opposed to the complete set of
expansions) resulting from the expansion of a word on the command line

extensions
for X server extensions

file-descriptors
for numbers of open file descriptors

files the generic file-matching tag used by functions completing filenames

fonts for X font names

fstypes
for file system types (e.g. for the mount command)

functions
names of functions -- normally shell functions, although certain commands may under‐
stand other kinds of function

globbed-files
for filenames when the name has been generated by pattern matching

groups for names of user groups

history-words
for words from the history

hosts for hostnames

indexes
for array indexes

jobs for jobs (as listed by the `jobs' builtin)

interfaces
for network interfaces

keymaps
for names of zsh keymaps

keysyms
for names of X keysyms

libraries
for names of system libraries

limits for system limits

local-directories
for names of directories that are subdirectories of the current working directory when
completing arguments of cd and related builtin commands (compare path-directories) --
when the cdpath array is unset, directories is used instead

manuals
for names of manual pages

mailboxes
for e-mail folders

maps for map names (e.g. NIS maps)

messages
used to look up the format style for messages

modifiers
for names of X modifiers

modules
for modules (e.g. zsh modules)

my-accounts
used to look up the users-hosts style

named-directories
for named directories (you wouldn't have guessed that, would you?)

names for all kinds of names

newsgroups
for USENET groups

nicknames
for nicknames of NIS maps

options
for command options

original
used by the _approximate, _correct and _expand completers when offering the original
string as a match

other-accounts
used to look up the users-hosts style

other-files
for the names of any non-directory files. This is used instead of all-files when the
list-dirs-first style is in effect.

packages
for packages (e.g. rpm or installed Debian packages)

parameters
for names of parameters

path-directories
for names of directories found by searching the cdpath array when completing arguments
of cd and related builtin commands (compare local-directories)

paths used to look up the values of the expand, ambiguous and special-dirs styles

pods for perl pods (documentation files)

ports for communication ports

prefixes
for prefixes (like those of a URL)

printers
for print queue names

processes
for process identifiers

processes-names
used to look up the command style when generating the names of processes for killall

sequences
for sequences (e.g. mh sequences)

sessions
for sessions in the zftp function suite

signals
for signal names

strings
for strings (e.g. the replacement strings for the cd builtin command)

styles for styles used by the zstyle builtin command

suffixes
for filename extensions

tags for tags (e.g. rpm tags)

targets
for makefile targets

time-zones
for time zones (e.g. when setting the TZ parameter)

types for types of whatever (e.g. address types for the xhost command)

urls used to look up the urls and local styles when completing URLs

users for usernames

values for one of a set of values in certain lists

variant
used by _pick_variant to look up the command to run when determining what program is
installed for a particular command name.

visuals
for X visuals

warnings
used to look up the format style for warnings

widgets
for zsh widget names

windows
for IDs of X windows

zsh-options
for shell options

Standard Styles
Note that the values of several of these styles represent boolean values. Any of the strings
`true', `on', `yes', and `1' can be used for the value `true' and any of the strings `false',
`off', `no', and `0' for the value `false'. The behavior for any other value is undefined
except where explicitly mentioned. The default value may be either `true' or `false' if the
style is not set.

Some of these styles are tested first for every possible tag corresponding to a type of
match, and if no style was found, for the default tag. The most notable styles of this type
are menu, list-colors and styles controlling completion listing such as list-packed and
last-prompt. When tested for the default tag, only the function field of the context will be
set so that a style using the default tag will normally be defined along the lines of:

zstyle ':completion:*:default' menu ...

accept-exact
This is tested for the default tag in addition to the tags valid for the current con‐
text. If it is set to `true' and any of the trial matches is the same as the string
on the command line, this match will immediately be accepted (even if it would other‐
wise be considered ambiguous).

When completing pathnames (where the tag used is `paths') this style accepts any num‐
ber of patterns as the value in addition to the boolean values. Pathnames matching
one of these patterns will be accepted immediately even if the command line contains
some more partially typed pathname components and these match no file under the direc‐
tory accepted.

This style is also used by the _expand completer to decide if words beginning with a
tilde or parameter expansion should be expanded. For example, if there are parameters
foo and foobar, the string `$foo' will only be expanded if accept-exact is set to
`true'; otherwise the completion system will be allowed to complete $foo to $foobar.
If the style is set to `continue', _expand will add the expansion as a match and the
completion system will also be allowed to continue.

accept-exact-dirs
This is used by filename completion. Unlike accept-exact it is a boolean. By de‐
fault, filename completion examines all components of a path to see if there are com‐
pletions of that component, even if the component matches an existing directory. For
example, when completion after /usr/bin/, the function examines possible completions
to /usr.

When this style is `true', any prefix of a path that matches an existing directory is
accepted without any attempt to complete it further. Hence, in the given example, the
path /usr/bin/ is accepted immediately and completion tried in that directory.

This style is also useful when completing after directories that magically appear when
referenced, such as ZFS .zfs directories or NetApp .snapshot directories. When the
style is set the shell does not check for the existence of the directory within the
parent directory.

If you wish to inhibit this behaviour entirely, set the path-completion style (see be‐
low) to `false'.

add-space
This style is used by the _expand completer. If it is `true' (the default), a space
will be inserted after all words resulting from the expansion, or a slash in the case
of directory names. If the value is `file', the completer will only add a space to
names of existing files. Either a boolean `true' or the value `file' may be combined
with `subst', in which case the completer will not add a space to words generated from
the expansion of a substitution of the form `$(...)' or `${...}'.

The _prefix completer uses this style as a simple boolean value to decide if a space
should be inserted before the suffix.

ambiguous
This applies when completing non-final components of filename paths, in other words
those with a trailing slash. If it is set, the cursor is left after the first ambigu‐
ous component, even if menu completion is in use. The style is always tested with the
paths tag.

assign-list
When completing after an equals sign that is being treated as an assignment, the com‐
pletion system normally completes only one filename. In some cases the value may be
a list of filenames separated by colons, as with PATH and similar parameters. This
style can be set to a list of patterns matching the names of such parameters.

The default is to complete lists when the word on the line already contains a colon.

auto-description
If set, this style's value will be used as the description for options that are not
described by the completion functions, but that have exactly one argument. The se‐
quence `%d' in the value will be replaced by the description for this argument. De‐
pending on personal preferences, it may be useful to set this style to something like
`specify: %d'. Note that this may not work for some commands.

avoid-completer
This is used by the _all_matches completer to decide if the string consisting of all
matches should be added to the list currently being generated. Its value is a list of
names of completers. If any of these is the name of the completer that generated the
matches in this completion, the string will not be added.

The default value for this style is `_expand _old_list _correct _approximate', i.e. it
contains the completers for which a string with all matches will almost never be
wanted.

cache-path
This style defines the path where any cache files containing dumped completion data
are stored. It defaults to `$ZDOTDIR/.zcompcache', or `$HOME/.zcompcache' if $ZDOTDIR
is not defined. The completion cache will not be used unless the use-cache style is
set.

cache-policy
This style defines the function that will be used to determine whether a cache needs
rebuilding. See the section on the _cache_invalid function below.

call-command
This style is used in the function for commands such as make and ant where calling the
command directly to generate matches suffers problems such as being slow or, as in the
case of make can potentially cause actions in the makefile to be executed. If it is
set to `true' the command is called to generate matches. The default value of this
style is `false'.

command
In many places, completion functions need to call external commands to generate the
list of completions. This style can be used to override the command that is called in
some such cases. The elements of the value are joined with spaces to form a command
line to execute. The value can also start with a hyphen, in which case the usual com‐
mand will be added to the end; this is most useful for putting `builtin' or `command'
in front to make sure the appropriate version of a command is called, for example to
avoid calling a shell function with the same name as an external command.

As an example, the completion function for process IDs uses this style with the pro‐‐
cesses tag to generate the IDs to complete and the list of processes to display (if
the verbose style is `true'). The list produced by the command should look like the
output of the ps command. The first line is not displayed, but is searched for the
string `PID' (or `pid') to find the position of the process IDs in the following
lines. If the line does not contain `PID', the first numbers in each of the other
lines are taken as the process IDs to complete.

Note that the completion function generally has to call the specified command for each
attempt to generate the completion list. Hence care should be taken to specify only
commands that take a short time to run, and in particular to avoid any that may never
terminate.

command-path
This is a list of directories to search for commands to complete. The default for
this style is the value of the special parameter path.

commands
This is used by the function completing sub-commands for the system initialisation
scripts (residing in /etc/init.d or somewhere not too far away from that). Its values
give the default commands to complete for those commands for which the completion
function isn't able to find them out automatically. The default for this style are
the two strings `start' and `stop'.

complete
This is used by the _expand_alias function when invoked as a bindable command. If set
to `true' and the word on the command line is not the name of an alias, matching alias
names will be completed.

complete-options
This is used by the completer for cd, chdir and pushd. For these commands a - is used
to introduce a directory stack entry and completion of these is far more common than
completing options. Hence unless the value of this style is `true' options will not
be completed, even after an initial -. If it is `true', options will be completed af‐
ter an initial - unless there is a preceding -- on the command line.

completer
The strings given as the value of this style provide the names of the completer func‐
tions to use. The available completer functions are described in the section `Control
Functions' below.

Each string may be either the name of a completer function or a string of the form
`function:name'. In the first case the completer field of the context will contain
the name of the completer without the leading underscore and with all other under‐
scores replaced by hyphens. In the second case the function is the name of the com‐
pleter to call, but the context will contain the user-defined name in the completer
field of the context. If the name starts with a hyphen, the string for the context
will be build from the name of the completer function as in the first case with the
name appended to it. For example:

zstyle ':completion:*' completer _complete _complete:-foo

Here, completion will call the _complete completer twice, once using `complete' and
once using `complete-foo' in the completer field of the context. Normally, using the
same completer more than once only makes sense when used with the `functions:name'
form, because otherwise the context name will be the same in all calls to the com‐
pleter; possible exceptions to this rule are the _ignored and _prefix completers.

The default value for this style is `_complete _ignored': only completion will be
done, first using the ignored-patterns style and the $fignore array and then without
ignoring matches.

condition
This style is used by the _list completer function to decide if insertion of matches
should be delayed unconditionally. The default is `true'.

delimiters
This style is used when adding a delimiter for use with history modifiers or glob
qualifiers that have delimited arguments. It is an array of preferred delimiters to
add. Non-special characters are preferred as the completion system may otherwise be‐
come confused. The default list is :, +, /, -, %. The list may be empty to force a
delimiter to be typed.

disabled
If this is set to `true', the _expand_alias completer and bindable command will try to
expand disabled aliases, too. The default is `false'.

domains
A list of names of network domains for completion. If this is not set, domain names
will be taken from the file /etc/resolv.conf.

environ
The environ style is used when completing for `sudo'. It is set to an array of
`VAR=value' assignments to be exported into the local environment before the comple‐
tion for the target command is invoked.
zstyle ':completion:*:sudo::' environ \
PATH="/sbin:/usr/sbin:$PATH" HOME="/root"

expand This style is used when completing strings consisting of multiple parts, such as path
names.

If one of its values is the string `prefix', the partially typed word from the line
will be expanded as far as possible even if trailing parts cannot be completed.

If one of its values is the string `suffix', matching names for components after the
first ambiguous one will also be added. This means that the resulting string is the
longest unambiguous string possible. However, menu completion can be used to cycle
through all matches.

fake This style may be set for any completion context. It specifies additional strings
that will always be completed in that context. The form of each string is `value:de‐
scription'; the colon and description may be omitted, but any literal colons in value
must be quoted with a backslash. Any description provided is shown alongside the
value in completion listings.

It is important to use a sufficiently restrictive context when specifying fake
strings. Note that the styles fake-files and fake-parameters provide additional fea‐
tures when completing files or parameters.

fake-always
This works identically to the fake style except that the ignored-patterns style is not
applied to it. This makes it possible to override a set of matches completely by set‐
ting the ignored patterns to `*'.

The following shows a way of supplementing any tag with arbitrary data, but having it
behave for display purposes like a separate tag. In this example we use the features
of the tag-order style to divide the named-directories tag into two when performing
completion with the standard completer complete for arguments of cd. The tag
named-directories-normal behaves as normal, but the tag named-directories-mine con‐
tains a fixed set of directories. This has the effect of adding the match group `ex‐‐
tra directories' with the given completions.

zstyle ':completion::complete:cd:*' tag-order \
'named-directories:-mine:extra\ directories
named-directories:-normal:named\ directories *'
zstyle ':completion::complete:cd:*:named-directories-mine' \
fake-always mydir1 mydir2
zstyle ':completion::complete:cd:*:named-directories-mine' \
ignored-patterns '*'

fake-files
This style is used when completing files and looked up without a tag. Its values are
of the form `dir:names...'. This will add the names (strings separated by spaces) as
possible matches when completing in the directory dir, even if no such files really
exist. The dir may be a pattern; pattern characters or colons in dir should be quoted
with a backslash to be treated literally.

This can be useful on systems that support special file systems whose top-level path‐
names can not be listed or generated with glob patterns (but see accept-exact-dirs for
a more general way of dealing with this problem). It can also be used for directories
for which one does not have read permission.

The pattern form can be used to add a certain `magic' entry to all directories on a
particular file system.

fake-parameters
This is used by the completion function for parameter names. Its values are names of
parameters that might not yet be set but should be completed nonetheless. Each name
may also be followed by a colon and a string specifying the type of the parameter
(like `scalar', `array' or `integer'). If the type is given, the name will only be
completed if parameters of that type are required in the particular context. Names
for which no type is specified will always be completed.

file-list
This style controls whether files completed using the standard builtin mechanism are
to be listed with a long list similar to ls -l. Note that this feature uses the shell
module zsh/stat for file information; this loads the builtin stat which will replace
any external stat executable. To avoid this the following code can be included in an
initialization file:

zmodload -i zsh/stat
disable stat

The style may either be set to a `true' value (or `all'), or one of the values `in‐‐
sert' or `list', indicating that files are to be listed in long format in all circum‐
stances, or when attempting to insert a file name, or when listing file names without
attempting to insert one.

More generally, the value may be an array of any of the above values, optionally fol‐
lowed by =num. If num is present it gives the maximum number of matches for which
long listing style will be used. For example,

zstyle ':completion:*' file-list list=20 insert=10

specifies that long format will be used when listing up to 20 files or inserting a
file with up to 10 matches (assuming a listing is to be shown at all, for example on
an ambiguous completion), else short format will be used.

zstyle -e ':completion:*' file-list \
'(( ${+NUMERIC} )) && reply=(true)'

specifies that long format will be used any time a numeric argument is supplied, else
short format.

file-patterns
This is used by the standard function for completing filenames, _files. If the style
is unset up to three tags are offered, `globbed-files',`directories' and `all-files',
depending on the types of files expected by the caller of _files. The first two
(`globbed-files' and `directories') are normally offered together to make it easier to
complete files in sub-directories.

The file-patterns style provides alternatives to the default tags, which are not used.
Its value consists of elements of the form `pattern:tag'; each string may contain any
number of such specifications separated by spaces.

The pattern is a pattern that is to be used to generate filenames. Any occurrence of
the sequence `%p' is replaced by any pattern(s) passed by the function calling _files.
Colons in the pattern must be preceded by a backslash to make them distinguishable
from the colon before the tag. If more than one pattern is needed, the patterns can
be given inside braces, separated by commas.

The tags of all strings in the value will be offered by _files and used when looking
up other styles. Any tags in the same word will be offered at the same time and be‐
fore later words. If no `:tag' is given the `files' tag will be used.

The tag may also be followed by an optional second colon and a description, which will
be used for the `%d' in the value of the format style (if that is set) instead of the
default description supplied by the completion function. If the description given
here contains itself a `%d', that is replaced with the description supplied by the
completion function.

For example, to make the rm command first complete only names of object files and then
the names of all files if there is no matching object file:

zstyle ':completion:*:*:rm:*:*' file-patterns \
'*.o:object-files' '%p:all-files'

To alter the default behaviour of file completion -- offer files matching a pattern
and directories on the first attempt, then all files -- to offer only matching files
on the first attempt, then directories, and finally all files:

zstyle ':completion:*' file-patterns \
'%p:globbed-files' '*(-/):directories' '*:all-files'

This works even where there is no special pattern: _files matches all files using the
pattern `*' at the first step and stops when it sees this pattern. Note also it will
never try a pattern more than once for a single completion attempt.

During the execution of completion functions, the EXTENDED_GLOB option is in effect,
so the characters `#', `~' and `^' have special meanings in the patterns.

file-sort
The standard filename completion function uses this style without a tag to determine
in which order the names should be listed; menu completion will cycle through them in
the same order. The possible values are: `size' to sort by the size of the file;
`links' to sort by the number of links to the file; `modification' (or `time' or
`date') to sort by the last modification time; `access' to sort by the last access
time; and `inode' (or `change') to sort by the last inode change time. If the style
is set to any other value, or is unset, files will be sorted alphabetically by name.
If the value contains the string `reverse', sorting is done in the opposite order. If
the value contains the string `follow', timestamps are associated with the targets of
symbolic links; the default is to use the timestamps of the links themselves.

file-split-chars
A set of characters that will cause all file completions for the given context to be
split at the point where any of the characters occurs. A typical use is to set the
style to :; then everything up to and including the last : in the string so far is ig‐
nored when completing files. As this is quite heavy-handed, it is usually preferable
to update completion functions for contexts where this behaviour is useful.

filter The ldap plugin of email address completion (see _email_addresses) uses this style to
specify the attributes to match against when filtering entries. So for example, if
the style is set to `sn', matching is done against surnames. Standard LDAP filtering
is used so normal completion matching is bypassed. If this style is not set, the LDAP
plugin is skipped. You may also need to set the command style to specify how to con‐
nect to your LDAP server.

force-list
This forces a list of completions to be shown at any point where listing is done, even
in cases where the list would usually be suppressed. For example, normally the list
is only shown if there are at least two different matches. By setting this style to
`always', the list will always be shown, even if there is only a single match that
will immediately be accepted. The style may also be set to a number. In this case
the list will be shown if there are at least that many matches, even if they would all
insert the same string.

This style is tested for the default tag as well as for each tag valid for the current
completion. Hence the listing can be forced only for certain types of match.

format If this is set for the descriptions tag, its value is used as a string to display
above matches in completion lists. The sequence `%d' in this string will be replaced
with a short description of what these matches are. This string may also contain the
output attribute sequences understood by compadd -X (see zshcompwid(1)).

The style is tested with each tag valid for the current completion before it is tested
for the descriptions tag. Hence different format strings can be defined for different
types of match.

Note also that some completer functions define additional `%'-sequences. These are
described for the completer functions that make use of them.

Some completion functions display messages that may be customised by setting this
style for the messages tag. Here, the `%d' is replaced with a message given by the
completion function.

Finally, the format string is looked up with the warnings tag, for use when no matches
could be generated at all. In this case the `%d' is replaced with the descriptions
for the matches that were expected separated by spaces. The sequence `%D' is replaced
with the same descriptions separated by newlines.

It is possible to use printf-style field width specifiers with `%d' and similar escape
sequences. This is handled by the zformat builtin command from the zsh/zutil module,
see zshmodules(1).

glob This is used by the _expand completer. If it is set to `true' (the default), globbing
will be attempted on the words resulting from a previous substitution (see the substi‐‐
tute style) or else the original string from the line.

global If this is set to `true' (the default), the _expand_alias completer and bindable com‐
mand will try to expand global aliases.

group-name
The completion system can group different types of matches, which appear in separate
lists. This style can be used to give the names of groups for particular tags. For
example, in command position the completion system generates names of builtin and ex‐
ternal commands, names of aliases, shell functions and parameters and reserved words
as possible completions. To have the external commands and shell functions listed
separately:

zstyle ':completion:*:*:-command-:*:commands' \
group-name commands
zstyle ':completion:*:*:-command-:*:functions' \
group-name functions

As a consequence, any match with the same tag will be displayed in the same group.

If the name given is the empty string the name of the tag for the matches will be used
as the name of the group. So, to have all different types of matches displayed sepa‐
rately, one can just set:

zstyle ':completion:*' group-name ''

All matches for which no group name is defined will be put in a group named -default-.

group-order
This style is additional to the group-name style to specify the order for display of
the groups defined by that style (compare tag-order, which determines which comple‐
tions appear at all). The groups named are shown in the given order; any other groups
are shown in the order defined by the completion function.

For example, to have names of builtin commands, shell functions and external commands
appear in that order when completing in command position:

zstyle ':completion:*:*:-command-:*:*' group-order \
builtins functions commands

groups A list of names of UNIX groups. If this is not set, group names are taken from the YP
database or the file `/etc/group'.

hidden If this is set to `true', matches for the given context will not be listed, although
any description for the matches set with the format style will be shown. If it is set
to `all', not even the description will be displayed.

Note that the matches will still be completed; they are just not shown in the list.
To avoid having matches considered as possible completions at all, the tag-order style
can be modified as described below.

hosts A list of names of hosts that should be completed. If this is not set, hostnames are
taken from the file `/etc/hosts'.

hosts-ports
This style is used by commands that need or accept hostnames and network ports. The
strings in the value should be of the form `host:port'. Valid ports are determined by
the presence of hostnames; multiple ports for the same host may appear.

ignore-line
This is tested for each tag valid for the current completion. If it is set to `true',
none of the words that are already on the line will be considered as possible comple‐
tions. If it is set to `current', the word the cursor is on will not be considered as
a possible completion. The value `current-shown' is similar but only applies if the
list of completions is currently shown on the screen. Finally, if the style is set to
`other', all words on the line except for the current one will be excluded from the
possible completions.

The values `current' and `current-shown' are a bit like the opposite of the accept-ex‐‐
act style: only strings with missing characters will be completed.

Note that you almost certainly don't want to set this to `true' or `other' for a gen‐
eral context such as `:completion:*'. This is because it would disallow completion
of, for example, options multiple times even if the command in question accepts the
option more than once.

ignore-parents
The style is tested without a tag by the function completing pathnames in order to de‐
termine whether to ignore the names of directories already mentioned in the current
word, or the name of the current working directory. The value must include one or
both of the following strings:

parent The name of any directory whose path is already contained in the word on the
line is ignored. For example, when completing after foo/../, the directory foo
will not be considered a valid completion.

pwd The name of the current working directory will not be completed; hence, for ex‐
ample, completion after ../ will not use the name of the current directory.

In addition, the value may include one or both of:

.. Ignore the specified directories only when the word on the line contains the
substring `../'.

directory
Ignore the specified directories only when names of directories are completed,
not when completing names of files.

Excluded values act in a similar fashion to values of the ignored-patterns style, so
they can be restored to consideration by the _ignored completer.

extra-verbose
If set, the completion listing is more verbose at the cost of a probable decrease in
completion speed. Completion performance will suffer if this style is set to `true'.

ignored-patterns
A list of patterns; any trial completion matching one of the patterns will be excluded
from consideration. The _ignored completer can appear in the list of completers to
restore the ignored matches. This is a more configurable version of the shell parame‐
ter $fignore.

Note that the EXTENDED_GLOB option is set during the execution of completion func‐
tions, so the characters `#', `~' and `^' have special meanings in the patterns.

insert This style is used by the _all_matches completer to decide whether to insert the list
of all matches unconditionally instead of adding the list as another match.

insert-ids
When completing process IDs, for example as arguments to the kill and wait builtins
the name of a command may be converted to the appropriate process ID. A problem
arises when the process name typed is not unique. By default (or if this style is set
explicitly to `menu') the name will be converted immediately to a set of possible IDs,
and menu completion will be started to cycle through them.

If the value of the style is `single', the shell will wait until the user has typed
enough to make the command unique before converting the name to an ID; attempts at
completion will be unsuccessful until that point. If the value is any other string,
menu completion will be started when the string typed by the user is longer than the
common prefix to the corresponding IDs.

insert-tab
If this is set to `true', the completion system will insert a TAB character (assuming
that was used to start completion) instead of performing completion when there is no
non-blank character to the left of the cursor. If it is set to `false', completion
will be done even there.

The value may also contain the substrings `pending' or `pending=val'. In this case,
the typed character will be inserted instead of starting completion when there is un‐
processed input pending. If a val is given, completion will not be done if there are
at least that many characters of unprocessed input. This is often useful when pasting
characters into a terminal. Note however, that it relies on the $PENDING special pa‐
rameter from the zsh/zle module being set properly which is not guaranteed on all
platforms.

The default value of this style is `true' except for completion within vared builtin
command where it is `false'.

insert-unambiguous
This is used by the _match and _approximate completers. These completers are often
used with menu completion since the word typed may bear little resemblance to the fi‐
nal completion. However, if this style is `true', the completer will start menu com‐
pletion only if it could find no unambiguous initial string at least as long as the
original string typed by the user.

In the case of the _approximate completer, the completer field in the context will al‐
ready have been set to one of correct-num or approximate-num, where num is the number
of errors that were accepted.

In the case of the _match completer, the style may also be set to the string `pat‐‐
tern'. Then the pattern on the line is left unchanged if it does not match unambigu‐
ously.

gain-privileges
If set to true, this style enables the use of commands like sudo or doas to gain extra
privileges when retrieving information for completion. This is only done when a com‐
mand such as sudo appears on the command-line. To force the use of, e.g. sudo or to
override any prefix that might be added due to gain-privileges, the command style can
be used with a value that begins with a hyphen.

keep-prefix
This style is used by the _expand completer. If it is `true', the completer will try
to keep a prefix containing a tilde or parameter expansion. Hence, for example, the
string `~/f*' would be expanded to `~/foo' instead of `/home/user/foo'. If the style
is set to `changed' (the default), the prefix will only be left unchanged if there
were other changes between the expanded words and the original word from the command
line. Any other value forces the prefix to be expanded unconditionally.

The behaviour of _expand when this style is `true' is to cause _expand to give up when
a single expansion with the restored prefix is the same as the original; hence any re‐
maining completers may be called.

last-prompt
This is a more flexible form of the ALWAYS_LAST_PROMPT option. If it is `true', the
completion system will try to return the cursor to the previous command line after
displaying a completion list. It is tested for all tags valid for the current comple‐
tion, then the default tag. The cursor will be moved back to the previous line if
this style is `true' for all types of match. Note that unlike the ALWAYS_LAST_PROMPT
option this is independent of the numeric argument.

known-hosts-files
This style should contain a list of files to search for host names and (if the use-ip
style is set) IP addresses in a format compatible with ssh known_hosts files. If it
is not set, the files /etc/ssh/ssh_known_hosts and ~/.ssh/known_hosts are used.

list This style is used by the _history_complete_word bindable command. If it is set to
`true' it has no effect. If it is set to `false' matches will not be listed. This
overrides the setting of the options controlling listing behaviour, in particular
AUTO_LIST. The context always starts with `:completion:history-words'.

list-colors
If the zsh/complist module is loaded, this style can be used to set color specifica‐
tions. This mechanism replaces the use of the ZLS_COLORS and ZLS_COLOURS parameters
described in the section `The zsh/complist Module' in zshmodules(1), but the syntax is
the same.

If this style is set for the default tag, the strings in the value are taken as speci‐
fications that are to be used everywhere. If it is set for other tags, the specifica‐
tions are used only for matches of the type described by the tag. For this to work
best, the group-name style must be set to an empty string.

In addition to setting styles for specific tags, it is also possible to use group
names specified explicitly by the group-name tag together with the `(group)' syntax
allowed by the ZLS_COLORS and ZLS_COLOURS parameters and simply using the default tag.

It is possible to use any color specifications already set up for the GNU version of
the ls command:

zstyle ':completion:*:default' list-colors \
${(s.:.)LS_COLORS}

The default colors are the same as for the GNU ls command and can be obtained by set‐
ting the style to an empty string (i.e. '').

list-dirs-first
This is used by file completion. If set, directories to be completed are listed sepa‐
rately from and before completion for other files, regardless of tag ordering. In ad‐
dition, the tag other-files is used in place of all-files for the remaining files, to
indicate that no directories are presented with that tag.

list-grouped
If this style is `true' (the default), the completion system will try to make certain
completion listings more compact by grouping matches. For example, options for com‐
mands that have the same description (shown when the verbose style is set to `true')
will appear as a single entry. However, menu selection can be used to cycle through
all the matches.

list-packed
This is tested for each tag valid in the current context as well as the default tag.
If it is set to `true', the corresponding matches appear in listings as if the
LIST_PACKED option were set. If it is set to `false', they are listed normally.

list-prompt
If this style is set for the default tag, completion lists that don't fit on the
screen can be scrolled (see the description of the zsh/complist module in zshmod‐
ules(1)). The value, if not the empty string, will be displayed after every screenful
and the shell will prompt for a key press; if the style is set to the empty string, a
default prompt will be used.

The value may contain the escape sequences: `%l' or `%L', which will be replaced by
the number of the last line displayed and the total number of lines; `%m' or `%M', the
number of the last match shown and the total number of matches; and `%p' and `%P',
`Top' when at the beginning of the list, `Bottom' when at the end and the position
shown as a percentage of the total length otherwise. In each case the form with the
uppercase letter will be replaced by a string of fixed width, padded to the right
with spaces, while the lowercase form will be replaced by a variable width string. As
in other prompt strings, the escape sequences `%S', `%s', `%B', `%b', `%U', `%u' for
entering and leaving the display modes standout, bold and underline, and `%F', `%f',
`%K', `%k' for changing the foreground background colour, are also available, as is
the form `%{...%}' for enclosing escape sequences which display with zero (or, with a
numeric argument, some other) width.

After deleting this prompt the variable LISTPROMPT should be unset for the removal to
take effect.

list-rows-first
This style is tested in the same way as the list-packed style and determines whether
matches are to be listed in a rows-first fashion as if the LIST_ROWS_FIRST option were
set.

list-suffixes
This style is used by the function that completes filenames. If it is `true', and
completion is attempted on a string containing multiple partially typed pathname com‐
ponents, all ambiguous components will be shown. Otherwise, completion stops at the
first ambiguous component.

list-separator
The value of this style is used in completion listing to separate the string to com‐
plete from a description when possible (e.g. when completing options). It defaults to
`--' (two hyphens).

local This is for use with functions that complete URLs for which the corresponding files
are available directly from the file system. Its value should consist of three
strings: a hostname, the path to the default web pages for the server, and the direc‐
tory name used by a user placing web pages within their home area.

For example:

zstyle ':completion:*' local toast \
/var/http/public/toast public_html

Completion after `http://toast/stuff/' will look for files in the directory
/var/http/public/toast/stuff, while completion after `http://toast/~yousir/' will
look for files in the directory ~yousir/public_html.

mail-directory
If set, zsh will assume that mailbox files can be found in the directory specified.
It defaults to `~/Mail'.

match-original
This is used by the _match completer. If it is set to only, _match will try to gener‐
ate matches without inserting a `*' at the cursor position. If set to any other
non-empty value, it will first try to generate matches without inserting the `*' and
if that yields no matches, it will try again with the `*' inserted. If it is unset or
set to the empty string, matching will only be performed with the `*' inserted.

matcher
This style is tested separately for each tag valid in the current context. Its value
is placed before any match specifications given by the matcher-list style so can over‐
ride them via the use of an x: specification. The value should be in the form de‐
scribed in the section `Completion Matching Control' in zshcompwid(1). For examples
of this, see the description of the tag-order style.

For notes comparing the use of this and the matcher-list style, see under the descrip‐
tion of the tag-order style.

matcher-list
This style can be set to a list of match specifications that are to be applied every‐
where. Match specifications are described in the section `Completion Matching Control'
in zshcompwid(1). The completion system will try them one after another for each com‐
pleter selected. For example, to try first simple completion and, if that generates
no matches, case-insensitive completion:

zstyle ':completion:*' matcher-list '' 'm:{a-zA-Z}={A-Za-z}'

By default each specification replaces the previous one; however, if a specification
is prefixed with +, it is added to the existing list. Hence it is possible to create
increasingly general specifications without repetition:

zstyle ':completion:*' matcher-list \
'' '+m:{a-z}={A-Z}' '+m:{A-Z}={a-z}'

It is possible to create match specifications valid for particular completers by using
the third field of the context. This applies only to completers that override the
global matcher-list, which as of this writing includes only _prefix and _ignored. For
example, to use the completers _complete and _prefix but allow case-insensitive com‐
pletion only with _complete:

zstyle ':completion:*' completer _complete _prefix
zstyle ':completion:*:complete:*:*:*' matcher-list \
'' 'm:{a-zA-Z}={A-Za-z}'

User-defined names, as explained for the completer style, are available. This makes
it possible to try the same completer more than once with different match specifica‐
tions each time. For example, to try normal completion without a match specification,
then normal completion with case-insensitive matching, then correction, and finally
partial-word completion:

zstyle ':completion:*' completer \
_complete _correct _complete:foo
zstyle ':completion:*:complete:*:*:*' matcher-list \
'' 'm:{a-zA-Z}={A-Za-z}'
zstyle ':completion:*:foo:*:*:*' matcher-list \
'm:{a-zA-Z}={A-Za-z} r:|[-_./]=* r:|=*'

If the style is unset in any context no match specification is applied. Note also
that some completers such as _correct and _approximate do not use the match specifica‐
tions at all, though these completers will only ever be called once even if the
matcher-list contains more than one element.

Where multiple specifications are useful, note that the entire completion is done for
each element of matcher-list, which can quickly reduce the shell's performance. As a
rough rule of thumb, one to three strings will give acceptable performance. On the
other hand, putting multiple space-separated values into the same string does not have
an appreciable impact on performance.

If there is no current matcher or it is empty, and the option NO_CASE_GLOB is in ef‐
fect, the matching for files is performed case-insensitively in any case. However,
any matcher must explicitly specify case-insensitive matching if that is required.

For notes comparing the use of this and the matcher style, see under the description
of the tag-order style.

max-errors
This is used by the _approximate and _correct completer functions to determine the
maximum number of errors to allow. The completer will try to generate completions by
first allowing one error, then two errors, and so on, until either a match or matches
were found or the maximum number of errors given by this style has been reached.

If the value for this style contains the string `numeric', the completer function will
take any numeric argument as the maximum number of errors allowed. For example, with

zstyle ':completion:*:approximate:::' max-errors 2 numeric

two errors are allowed if no numeric argument is given, but with a numeric argument of
six (as in `ESC-6 TAB'), up to six errors are accepted. Hence with a value of `0 nu‐‐
meric', no correcting completion will be attempted unless a numeric argument is given.

If the value contains the string `not-numeric', the completer will not try to generate
corrected completions when given a numeric argument, so in this case the number given
should be greater than zero. For example, `2 not-numeric' specifies that correcting
completion with two errors will usually be performed, but if a numeric argument is
given, correcting completion will not be performed.

The default value for this style is `2 numeric'.

max-matches-width
This style is used to determine the trade off between the width of the display used
for matches and the width used for their descriptions when the verbose style is in ef‐
fect. The value gives the number of display columns to reserve for the matches. The
default is half the width of the screen.

This has the most impact when several matches have the same description and so will be
grouped together. Increasing the style will allow more matches to be grouped to‐
gether; decreasing it will allow more of the description to be visible.

menu If this is `true' in the context of any of the tags defined for the current completion
menu completion will be used. The value for a specific tag will take precedence over
that for the `default' tag.

If none of the values found in this way is `true' but at least one is set to `auto',
the shell behaves as if the AUTO_MENU option is set.

If one of the values is explicitly set to `false', menu completion will be explicitly
turned off, overriding the MENU_COMPLETE option and other settings.

In the form `yes=num', where `yes' may be any of the `true' values (`yes', `true',
`on' and `1'), menu completion will be turned on if there are at least num matches.
In the form `yes=long', menu completion will be turned on if the list does not fit on
the screen. This does not activate menu completion if the widget normally only lists
completions, but menu completion can be activated in that case with the value
`yes=long-list' (Typically, the value `select=long-list' described later is more use‐
ful as it provides control over scrolling.)

Similarly, with any of the `false' values (as in `no=10'), menu completion will not be
used if there are num or more matches.

The value of this widget also controls menu selection, as implemented by the zsh/com‐‐
plist module. The following values may appear either alongside or instead of the val‐
ues above.

If the value contains the string `select', menu selection will be started uncondition‐
ally.

In the form `select=num', menu selection will only be started if there are at least
num matches. If the values for more than one tag provide a number, the smallest num‐
ber is taken.

Menu selection can be turned off explicitly by defining a value containing the
string`no-select'.

It is also possible to start menu selection only if the list of matches does not fit
on the screen by using the value `select=long'. To start menu selection even if the
current widget only performs listing, use the value `select=long-list'.

To turn on menu completion or menu selection when there are a certain number of
matches or the list of matches does not fit on the screen, both of `yes=' and `se‐‐
lect=' may be given twice, once with a number and once with `long' or `long-list'.

Finally, it is possible to activate two special modes of menu selection. The word
`interactive' in the value causes interactive mode to be entered immediately when menu
selection is started; see the description of the zsh/complist module in zshmodules(1)
for a description of interactive mode. Including the string `search' does the same
for incremental search mode. To select backward incremental search, include the
string `search-backward'.

muttrc If set, gives the location of the mutt configuration file. It defaults to `~/.mut‐‐
trc'.

numbers
This is used with the jobs tag. If it is `true', the shell will complete job numbers
instead of the shortest unambiguous prefix of the job command text. If the value is a
number, job numbers will only be used if that many words from the job descriptions are
required to resolve ambiguities. For example, if the value is `1', strings will only
be used if all jobs differ in the first word on their command lines.

old-list
This is used by the _oldlist completer. If it is set to `always', then standard wid‐
gets which perform listing will retain the current list of matches, however they were
generated; this can be turned off explicitly with the value `never', giving the behav‐
iour without the _oldlist completer. If the style is unset, or any other value, then
the existing list of completions is displayed if it is not already; otherwise, the
standard completion list is generated; this is the default behaviour of _oldlist.
However, if there is an old list and this style contains the name of the completer
function that generated the list, then the old list will be used even if it was gener‐
ated by a widget which does not do listing.

For example, suppose you type ^Xc to use the _correct_word widget, which generates a
list of corrections for the word under the cursor. Usually, typing ^D would generate
a standard list of completions for the word on the command line, and show that. With
_oldlist, it will instead show the list of corrections already generated.

As another example consider the _match completer: with the insert-unambiguous style
set to `true' it inserts only a common prefix string, if there is any. However, this
may remove parts of the original pattern, so that further completion could produce
more matches than on the first attempt. By using the _oldlist completer and setting
this style to _match, the list of matches generated on the first attempt will be used
again.

old-matches
This is used by the _all_matches completer to decide if an old list of matches should
be used if one exists. This is selected by one of the `true' values or by the string
`only'. If the value is `only', _all_matches will only use an old list and won't have
any effect on the list of matches currently being generated.

If this style is set it is generally unwise to call the _all_matches completer uncon‐
ditionally. One possible use is for either this style or the completer style to be
defined with the -e option to zstyle to make the style conditional.

old-menu
This is used by the _oldlist completer. It controls how menu completion behaves when
a completion has already been inserted and the user types a standard completion key
such as TAB. The default behaviour of _oldlist is that menu completion always contin‐
ues with the existing list of completions. If this style is set to `false', however,
a new completion is started if the old list was generated by a different completion
command; this is the behaviour without the _oldlist completer.

For example, suppose you type ^Xc to generate a list of corrections, and menu comple‐
tion is started in one of the usual ways. Usually, or with this style set to `false',
typing TAB at this point would start trying to complete the line as it now appears.
With _oldlist, it instead continues to cycle through the list of corrections.

original
This is used by the _approximate and _correct completers to decide if the original
string should be added as a possible completion. Normally, this is done only if there
are at least two possible corrections, but if this style is set to `true', it is al‐
ways added. Note that the style will be examined with the completer field in the con‐
text name set to correct-num or approximate-num, where num is the number of errors
that were accepted.

packageset
This style is used when completing arguments of the Debian `dpkg' program. It con‐
tains an override for the default package set for a given context. For example,

zstyle ':completion:*:complete:dpkg:option--status-1:*' \
packageset avail

causes available packages, rather than only installed packages, to be completed for
`dpkg --status'.

path The function that completes color names uses this style with the colors tag. The
value should be the pathname of a file containing color names in the format of an X11
rgb.txt file. If the style is not set but this file is found in one of various stan‐
dard locations it will be used as the default.

path-completion
This is used by filename completion. By default, filename completion examines all
components of a path to see if there are completions of that component. For example,
/u/b/z can be completed to /usr/bin/zsh. Explicitly setting this style to `false' in‐
hibits this behaviour for path components up to the / before the cursor; this over‐
rides the setting of accept-exact-dirs.

Even with the style set to `false', it is still possible to complete multiple paths by
setting the option COMPLETE_IN_WORD and moving the cursor back to the first component
in the path to be completed. For example, /u/b/z can be completed to /usr/bin/zsh if
the cursor is after the /u.

pine-directory
If set, specifies the directory containing PINE mailbox files. There is no default,
since recursively searching this directory is inconvenient for anyone who doesn't use
PINE.

ports A list of Internet service names (network ports) to complete. If this is not set,
service names are taken from the file `/etc/services'.

prefix-hidden
This is used for certain completions which share a common prefix, for example command
options beginning with dashes. If it is `true', the prefix will not be shown in the
list of matches.

The default value for this style is `false'.

prefix-needed
This style is also relevant for matches with a common prefix. If it is set to `true'
this common prefix must be typed by the user to generate the matches.

The style is applicable to the options, signals, jobs, functions, and parameters com‐
pletion tags.

For command options, this means that the initial `-', `+', or `--' must be typed ex‐
plicitly before option names will be completed.

For signals, an initial `-' is required before signal names will be completed.

For jobs, an initial `%' is required before job names will be completed.

For function and parameter names, an initial `_' or `.' is required before function or
parameter names starting with those characters will be completed.

The default value for this style is `false' for function and parameter completions,
and `true' otherwise.

preserve-prefix
This style is used when completing path names. Its value should be a pattern matching
an initial prefix of the word to complete that should be left unchanged under all cir‐
cumstances. For example, on some Unices an initial `//' (double slash) has a special
meaning; setting this style to the string `//' will preserve it. As another example,
setting this style to `?:/' under Cygwin would allow completion after `a:/...' and so
on.

range This is used by the _history completer and the _history_complete_word bindable command
to decide which words should be completed.

If it is a single number, only the last N words from the history will be completed.

If it is a range of the form `max:slice', the last slice words will be completed; then
if that yields no matches, the slice words before those will be tried and so on. This
process stops either when at least one match has been found, or max words have been
tried.

The default is to complete all words from the history at once.

recursive-files
If this style is set, its value is an array of patterns to be tested against `$PWD/':
note the trailing slash, which allows directories in the pattern to be delimited unam‐
biguously by including slashes on both sides. If an ordinary file completion fails
and the word on the command line does not yet have a directory part to its name, the
style is retrieved using the same tag as for the completion just attempted, then the
elements tested against $PWD/ in turn. If one matches, then the shell reattempts com‐
pletion by prepending the word on the command line with each directory in the expan‐
sion of **/*(/) in turn. Typically the elements of the style will be set to restrict
the number of directories beneath the current one to a manageable number, for example
`*/.git/*'.

For example,

zstyle ':completion:*' recursive-files '*/zsh/*'

If the current directory is /home/pws/zsh/Src, then zle_trTAB can be completed to
Zle/zle_tricky.c.

regular
This style is used by the _expand_alias completer and bindable command. If set to
`true' (the default), regular aliases will be expanded but only in command position.
If it is set to `false', regular aliases will never be expanded. If it is set to
`always', regular aliases will be expanded even if not in command position.

rehash If this is set when completing external commands, the internal list (hash) of commands
will be updated for each search by issuing the rehash command. There is a speed pen‐
alty for this which is only likely to be noticeable when directories in the path have
slow file access.

remote-access
If set to `false', certain commands will be prevented from making Internet connections
to retrieve remote information. This includes the completion for the CVS command.

It is not always possible to know if connections are in fact to a remote site, so some
may be prevented unnecessarily.

remove-all-dups
The _history_complete_word bindable command and the _history completer use this to de‐
cide if all duplicate matches should be removed, rather than just consecutive dupli‐
cates.

select-prompt
If this is set for the default tag, its value will be displayed during menu selection
(see the menu style above) when the completion list does not fit on the screen as a
whole. The same escapes as for the list-prompt style are understood, except that the
numbers refer to the match or line the mark is on. A default prompt is used when the
value is the empty string.

select-scroll
This style is tested for the default tag and determines how a completion list is
scrolled during a menu selection (see the menu style above) when the completion list
does not fit on the screen as a whole. If the value is `0' (zero), the list is
scrolled by half-screenfuls; if it is a positive integer, the list is scrolled by the
given number of lines; if it is a negative number, the list is scrolled by a screenful
minus the absolute value of the given number of lines. The default is to scroll by
single lines.

separate-sections
This style is used with the manuals tag when completing names of manual pages. If it
is `true', entries for different sections are added separately using tag names of the
form `manual.X', where X is the section number. When the group-name style is also in
effect, pages from different sections will appear separately. This style is also used
similarly with the words style when completing words for the dict command. It allows
words from different dictionary databases to be added separately. The default for
this style is `false'.

show-ambiguity
If the zsh/complist module is loaded, this style can be used to highlight the first
ambiguous character in completion lists. The value is either a color indication such
as those supported by the list-colors style or, with a value of `true', a default of
underlining is selected. The highlighting is only applied if the completion display
strings correspond to the actual matches.

show-completer
Tested whenever a new completer is tried. If it is `true', the completion system out‐
puts a progress message in the listing area showing what completer is being tried.
The message will be overwritten by any output when completions are found and is re‐
moved after completion is finished.

single-ignored
This is used by the _ignored completer when there is only one match. If its value is
`show', the single match will be displayed but not inserted. If the value is `menu',
then the single match and the original string are both added as matches and menu com‐
pletion is started, making it easy to select either of them.

sort This allows the standard ordering of matches to be overridden.

If its value is `true' or `false', sorting is enabled or disabled. Additionally the
values associated with the `-o' option to compadd can also be listed: match, nosort,
numeric, reverse. If it is not set for the context, the standard behaviour of the
calling widget is used.

The style is tested first against the full context including the tag, and if that
fails to produce a value against the context without the tag.

In many cases where a calling widget explicitly selects a particular ordering in lieu
of the default, a value of `true' is not honoured. An example of where this is not
the case is for command history where the default of sorting matches chronologically
may be overridden by setting the style to `true'.

In the _expand completer, if it is set to `true', the expansions generated will always
be sorted. If it is set to `menu', then the expansions are only sorted when they are
offered as single strings but not in the string containing all possible expansions.

special-dirs
Normally, the completion code will not produce the directory names `.' and `..' as
possible completions. If this style is set to `true', it will add both `.' and `..'
as possible completions; if it is set to `..', only `..' will be added.

The following example sets special-dirs to `..' when the current prefix is empty, is a
single `.', or consists only of a path beginning with `../'. Otherwise the value is
`false'.

zstyle -e ':completion:*' special-dirs \
'[[ $PREFIX = (../)#(|.|..) ]] && reply=(..)'

squeeze-slashes
If set to `true', sequences of slashes in filename paths (for example in `foo//bar')
will be treated as a single slash. This is the usual behaviour of UNIX paths. How‐
ever, by default the file completion function behaves as if there were a `*' between
the slashes.

stop If set to `true', the _history_complete_word bindable command will stop once when
reaching the beginning or end of the history. Invoking _history_complete_word will
then wrap around to the opposite end of the history. If this style is set to `false'
(the default), _history_complete_word will loop immediately as in a menu completion.

strip-comments
If set to `true', this style causes non-essential comment text to be removed from com‐
pletion matches. Currently it is only used when completing e-mail addresses where it
removes any display name from the addresses, cutting them down to plain user@host
form.

subst-globs-only
This is used by the _expand completer. If it is set to `true', the expansion will
only be used if it resulted from globbing; hence, if expansions resulted from the use
of the substitute style described below, but these were not further changed by glob‐
bing, the expansions will be rejected.

The default for this style is `false'.

substitute
This boolean style controls whether the _expand completer will first try to expand all
substitutions in the string (such as `$(...)' and `${...}').

The default is `true'.

suffix This is used by the _expand completer if the word starts with a tilde or contains a
parameter expansion. If it is set to `true', the word will only be expanded if it
doesn't have a suffix, i.e. if it is something like `~foo' or `$foo' rather than
`~foo/' or `$foo/bar', unless that suffix itself contains characters eligible for ex‐
pansion. The default for this style is `true'.

tag-order
This provides a mechanism for sorting how the tags available in a particular context
will be used.

The values for the style are sets of space-separated lists of tags. The tags in each
value will be tried at the same time; if no match is found, the next value is used.
(See the file-patterns style for an exception to this behavior.)

For example:

zstyle ':completion:*:complete:-command-:*:*' tag-order \
'commands functions'

specifies that completion in command position first offers external commands and shell
functions. Remaining tags will be tried if no completions are found.

In addition to tag names, each string in the value may take one of the following
forms:

- If any value consists of only a hyphen, then only the tags specified in the
other values are generated. Normally all tags not explicitly selected are
tried last if the specified tags fail to generate any matches. This means that
a single value consisting only of a single hyphen turns off completion.

! tags...
A string starting with an exclamation mark specifies names of tags that are not
to be used. The effect is the same as if all other possible tags for the con‐
text had been listed.

tag:label ...
Here, tag is one of the standard tags and label is an arbitrary name. Matches
are generated as normal but the name label is used in contexts instead of tag.
This is not useful in words starting with !.

If the label starts with a hyphen, the tag is prepended to the label to form
the name used for lookup. This can be used to make the completion system try a
certain tag more than once, supplying different style settings for each at‐
tempt; see below for an example.

tag:label:description
As before, but description will replace the `%d' in the value of the format
style instead of the default description supplied by the completion function.
Spaces in the description must be quoted with a backslash. A `%d' appearing in
description is replaced with the description given by the completion function.

In any of the forms above the tag may be a pattern or several patterns in the form
`{pat1,pat2...}'. In this case all matching tags will be used except for any given
explicitly in the same string.

One use of these features is to try one tag more than once, setting other styles dif‐
ferently on each attempt, but still to use all the other tags without having to repeat
them all. For example, to make completion of function names in command position ig‐
nore all the completion functions starting with an underscore the first time comple‐
tion is tried:

zstyle ':completion:*:*:-command-:*:*' tag-order \
'functions:-non-comp *' functions
zstyle ':completion:*:functions-non-comp' \
ignored-patterns '_*'

On the first attempt, all tags will be offered but the functions tag will be replaced
by functions-non-comp. The ignored-patterns style is set for this tag to exclude
functions starting with an underscore. If there are no matches, the second value of
the tag-order style is used which completes functions using the default tag, this time
presumably including all function names.

The matches for one tag can be split into different groups. For example:

zstyle ':completion:*' tag-order \
'options:-long:long\ options
options:-short:short\ options
options:-single-letter:single\ letter\ options'
zstyle ':completion:*:options-long' \
ignored-patterns '[-+](|-|[^-]*)'
zstyle ':completion:*:options-short' \
ignored-patterns '--*' '[-+]?'
zstyle ':completion:*:options-single-letter' \
ignored-patterns '???*'

With the group-names style set, options beginning with `--', options beginning with a
single `-' or `+' but containing multiple characters, and single-letter options will
be displayed in separate groups with different descriptions.

Another use of patterns is to try multiple match specifications one after another.
The matcher-list style offers something similar, but it is tested very early in the
completion system and hence can't be set for single commands nor for more specific
contexts. Here is how to try normal completion without any match specification and,
if that generates no matches, try again with case-insensitive matching, restricting
the effect to arguments of the command foo:

zstyle ':completion:*:*:foo:*:*' tag-order '*' '*:-case'
zstyle ':completion:*-case' matcher 'm:{a-z}={A-Z}'

First, all the tags offered when completing after foo are tried using the normal tag
name. If that generates no matches, the second value of tag-order is used, which
tries all tags again except that this time each has -case appended to its name for
lookup of styles. Hence this time the value for the matcher style from the second
call to zstyle in the example is used to make completion case-insensitive.

It is possible to use the -e option of the zstyle builtin command to specify condi‐
tions for the use of particular tags. For example:

zstyle -e '*:-command-:*' tag-order '
if [[ -n $PREFIX$SUFFIX ]]; then
reply=( )
else
reply=( - )
fi'

Completion in command position will be attempted only if the string typed so far is
not empty. This is tested using the PREFIX special parameter; see zshcompwid for a
description of parameters which are special inside completion widgets. Setting reply
to an empty array provides the default behaviour of trying all tags at once; setting
it to an array containing only a hyphen disables the use of all tags and hence of all
completions.

If no tag-order style has been defined for a context, the strings `(|*-)argument-*
(|*-)option-* values' and `options' plus all tags offered by the completion function
will be used to provide a sensible default behavior that causes arguments (whether
normal command arguments or arguments of options) to be completed before option names
for most commands.

urls This is used together with the urls tag by functions completing URLs.

If the value consists of more than one string, or if the only string does not name a
file or directory, the strings are used as the URLs to complete.

If the value contains only one string which is the name of a normal file the URLs are
taken from that file (where the URLs may be separated by white space or newlines).

Finally, if the only string in the value names a directory, the directory hierarchy
rooted at this directory gives the completions. The top level directory should be the
file access method, such as `http', `ftp', `bookmark' and so on. In many cases the
next level of directories will be a filename. The directory hierarchy can descend as
deep as necessary.

For example,

zstyle ':completion:*' urls ~/.urls
mkdir -p ~/.urls/ftp/ftp.zsh.org/pub

allows completion of all the components of the URL ftp://ftp.zsh.org/pub after suit‐
able commands such as `netscape' or `lynx'. Note, however, that access methods and
files are completed separately, so if the hosts style is set hosts can be completed
without reference to the urls style.

See the description in the function _urls itself for more information (e.g. `more
$^fpath/_urls(N)').

use-cache
If this is set, the completion caching layer is activated for any completions which
use it (via the _store_cache, _retrieve_cache, and _cache_invalid functions). The di‐
rectory containing the cache files can be changed with the cache-path style.

use-compctl
If this style is set to a string not equal to false, 0, no, and off, the completion
system may use any completion specifications defined with the compctl builtin command.
If the style is unset, this is done only if the zsh/compctl module is loaded. The
string may also contain the substring `first' to use completions defined with `compctl
-T', and the substring `default' to use the completion defined with `compctl -D'.

Note that this is only intended to smooth the transition from compctl to the new com‐
pletion system and may disappear in the future.

Note also that the definitions from compctl will only be used if there is no specific
completion function for the command in question. For example, if there is a function
_foo to complete arguments to the command foo, compctl will never be invoked for foo.
However, the compctl version will be tried if foo only uses default completion.

use-ip By default, the function _hosts that completes host names strips IP addresses from en‐
tries read from host databases such as NIS and ssh files. If this style is `true',
the corresponding IP addresses can be completed as well. This style is not use in any
context where the hosts style is set; note also it must be set before the cache of
host names is generated (typically the first completion attempt).

users This may be set to a list of usernames to be completed. If it is not set all user‐
names will be completed. Note that if it is set only that list of users will be com‐
pleted; this is because on some systems querying all users can take a prohibitive
amount of time.

users-hosts
The values of this style should be of the form `user@host' or `user:host'. It is used
for commands that need pairs of user- and hostnames. These commands will complete
usernames from this style (only), and will restrict subsequent hostname completion to
hosts paired with that user in one of the values of the style.

It is possible to group values for sets of commands which allow a remote login, such
as rlogin and ssh, by using the my-accounts tag. Similarly, values for sets of com‐
mands which usually refer to the accounts of other people, such as talk and finger,
can be grouped by using the other-accounts tag. More ambivalent commands may use the
accounts tag.

users-hosts-ports
Like users-hosts but used for commands like telnet and containing strings of the form
`user@host:port'.

verbose
If set, as it is by default, the completion listing is more verbose. In particular
many commands show descriptions for options if this style is `true'.

word This is used by the _list completer, which prevents the insertion of completions until
a second completion attempt when the line has not changed. The normal way of finding
out if the line has changed is to compare its entire contents between the two occa‐
sions. If this style is `true', the comparison is instead performed only on the cur‐
rent word. Hence if completion is performed on another word with the same contents,
completion will not be delayed.

CONTROL FUNCTIONS
The initialization script compinit redefines all the widgets which perform completion to call
the supplied widget function _main_complete. This function acts as a wrapper calling the
so-called `completer' functions that generate matches. If _main_complete is called with ar‐
guments, these are taken as the names of completer functions to be called in the order given.
If no arguments are given, the set of functions to try is taken from the completer style.
For example, to use normal completion and correction if that doesn't generate any matches:

zstyle ':completion:*' completer _complete _correct

after calling compinit. The default value for this style is `_complete _ignored', i.e. nor‐
mally only ordinary completion is tried, first with the effect of the ignored-patterns style
and then without it. The _main_complete function uses the return status of the completer
functions to decide if other completers should be called. If the return status is zero, no
other completers are tried and the _main_complete function returns.

If the first argument to _main_complete is a single hyphen, the arguments will not be taken
as names of completers. Instead, the second argument gives a name to use in the completer
field of the context and the other arguments give a command name and arguments to call to
generate the matches.

The following completer functions are contained in the distribution, although users may write
their own. Note that in contexts the leading underscore is stripped, for example basic com‐
pletion is performed in the context `:completion::complete:...'.

_all_matches
This completer can be used to add a string consisting of all other matches. As it in‐
fluences later completers it must appear as the first completer in the list. The list
of all matches is affected by the avoid-completer and old-matches styles described
above.

It may be useful to use the _generic function described below to bind _all_matches to
its own keystroke, for example:

zle -C all-matches complete-word _generic
bindkey '^Xa' all-matches
zstyle ':completion:all-matches:*' old-matches only
zstyle ':completion:all-matches::::' completer _all_matches

Note that this does not generate completions by itself: first use any of the standard
ways of generating a list of completions, then use ^Xa to show all matches. It is
possible instead to add a standard completer to the list and request that the list of
all matches should be directly inserted:

zstyle ':completion:all-matches::::' completer \
_all_matches _complete
zstyle ':completion:all-matches:*' insert true

In this case the old-matches style should not be set.

_approximate
This is similar to the basic _complete completer but allows the completions to undergo
corrections. The maximum number of errors can be specified by the max-errors style;
see the description of approximate matching in zshexpn(1) for how errors are counted.
Normally this completer will only be tried after the normal _complete completer:

zstyle ':completion:*' completer _complete _approximate

This will give correcting completion if and only if normal completion yields no possi‐
ble completions. When corrected completions are found, the completer will normally
start menu completion allowing you to cycle through these strings.

This completer uses the tags corrections and original when generating the possible
corrections and the original string. The format style for the former may contain the
additional sequences `%e' and `%o' which will be replaced by the number of errors ac‐
cepted to generate the corrections and the original string, respectively.

The completer progressively increases the number of errors allowed up to the limit by
the max-errors style, hence if a completion is found with one error, no completions
with two errors will be shown, and so on. It modifies the completer name in the con‐
text to indicate the number of errors being tried: on the first try the completer
field contains `approximate-1', on the second try `approximate-2', and so on.

When _approximate is called from another function, the number of errors to accept may
be passed with the -a option. The argument is in the same format as the max-errors
style, all in one string.

Note that this completer (and the _correct completer mentioned below) can be quite ex‐
pensive to call, especially when a large number of errors are allowed. One way to
avoid this is to set up the completer style using the -e option to zstyle so that some
completers are only used when completion is attempted a second time on the same
string, e.g.:

zstyle -e ':completion:*' completer '
if [[ $_last_try != "$HISTNO$BUFFER$CURSOR" ]]; then
_last_try="$HISTNO$BUFFER$CURSOR"
reply=(_complete _match _prefix)
else
reply=(_ignored _correct _approximate)
fi'

This uses the HISTNO parameter and the BUFFER and CURSOR special parameters that are
available inside zle and completion widgets to find out if the command line hasn't
changed since the last time completion was tried. Only then are the _ignored, _cor‐‐
rect and _approximate completers called.

_canonical_paths [ -A var ] [ -N ] [ -MJV12nfX ] tag descr [ paths ... ]
This completion function completes all paths given to it, and also tries to offer com‐
pletions which point to the same file as one of the paths given (relative path when an
absolute path is given, and vice versa; when ..'s are present in the word to be com‐
pleted; and some paths got from symlinks).

-A, if specified, takes the paths from the array variable specified. Paths can also be
specified on the command line as shown above. -N, if specified, prevents canonicaliz‐
ing the paths given before using them for completion, in case they are already so. The
options -M, -J, -V, -1, -2, -n, -F, -X are passed to compadd.

See _description for a description of tag and descr.

_cmdambivalent
Completes the remaining positional arguments as an external command. The external
command and its arguments are completed as separate arguments (in a manner appropriate
for completing /usr/bin/env) if there are two or more remaining positional arguments
on the command line, and as a quoted command string (in the manner of system(...))
otherwise. See also _cmdstring and _precommand.

This function takes no arguments.

_cmdstring
Completes an external command as a single argument, as for system(...).

_complete
This completer generates all possible completions in a context-sensitive manner, i.e.
using the settings defined with the compdef function explained above and the current
settings of all special parameters. This gives the normal completion behaviour.

To complete arguments of commands, _complete uses the utility function _normal, which
is in turn responsible for finding the particular function; it is described below.
Various contexts of the form -context- are handled specifically. These are all men‐
tioned above as possible arguments to the #compdef tag.

Before trying to find a function for a specific context, _complete checks if the pa‐
rameter `compcontext' is set. Setting `compcontext' allows the usual completion dis‐
patching to be overridden which is useful in places such as a function that uses vared
for input. If it is set to an array, the elements are taken to be the possible matches
which will be completed using the tag `values' and the description `value'. If it is
set to an associative array, the keys are used as the possible completions and the
values (if non-empty) are used as descriptions for the matches. If `compcontext' is
set to a string containing colons, it should be of the form `tag:descr:action'. In
this case the tag and descr give the tag and description to use and the action indi‐
cates what should be completed in one of the forms accepted by the _arguments utility
function described below.

Finally, if `compcontext' is set to a string without colons, the value is taken as the
name of the context to use and the function defined for that context will be called.
For this purpose, there is a special context named -command-line- that completes whole
command lines (commands and their arguments). This is not used by the completion sys‐
tem itself but is nonetheless handled when explicitly called.

_correct
Generate corrections, but not completions, for the current word; this is similar to
_approximate but will not allow any number of extra characters at the cursor as that
completer does. The effect is similar to spell-checking. It is based on _approxi‐‐
mate, but the completer field in the context name is correct.

For example, with:

zstyle ':completion:::::' completer \
_complete _correct _approximate
zstyle ':completion:*:correct:::' max-errors 2 not-numeric
zstyle ':completion:*:approximate:::' max-errors 3 numeric

correction will accept up to two errors. If a numeric argument is given, correction
will not be performed, but correcting completion will be, and will accept as many er‐
rors as given by the numeric argument. Without a numeric argument, first correction
and then correcting completion will be tried, with the first one accepting two errors
and the second one accepting three errors.

When _correct is called as a function, the number of errors to accept may be given
following the -a option. The argument is in the same form a values to the accept
style, all in one string.

This completer function is intended to be used without the _approximate completer or,
as in the example, just before it. Using it after the _approximate completer is use‐
less since _approximate will at least generate the corrected strings generated by the
_correct completer -- and probably more.

_expand
This completer function does not really perform completion, but instead checks if the
word on the command line is eligible for expansion and, if it is, gives detailed con‐
trol over how this expansion is done. For this to happen, the completion system needs
to be invoked with complete-word, not expand-or-complete (the default binding for
TAB), as otherwise the string will be expanded by the shell's internal mechanism be‐
fore the completion system is started. Note also this completer should be called be‐
fore the _complete completer function.

The tags used when generating expansions are all-expansions for the string containing
all possible expansions, expansions when adding the possible expansions as single
matches and original when adding the original string from the line. The order in
which these strings are generated, if at all, can be controlled by the group-order and
tag-order styles, as usual.

The format string for all-expansions and for expansions may contain the sequence `%o'
which will be replaced by the original string from the line.

The kind of expansion to be tried is controlled by the substitute, glob and
subst-globs-only styles.

It is also possible to call _expand as a function, in which case the different modes
may be selected with options: -s for substitute, -g for glob and -o for
subst-globs-only.

_expand_alias
If the word the cursor is on is an alias, it is expanded and no other completers are
called. The types of aliases which are to be expanded can be controlled with the
styles regular, global and disabled.

This function is also a bindable command, see the section `Bindable Commands' below.

_extensions
If the cursor follows the string `*.', filename extensions are completed. The exten‐
sions are taken from files in current directory or a directory specified at the begin‐
ning of the current word. For exact matches, completion continues to allow other com‐
pleters such as _expand to expand the pattern. The standard add-space and prefix-hid‐‐
den styles are observed.

_external_pwds
Completes current directories of other zsh processes belonging to the current user.

This is intended to be used via _generic, bound to a custom key combination. Note that
pattern matching is enabled so matching is performed similar to how it works with the
_match completer.

_history
Complete words from the shell's command history. This completer can be controlled by
the remove-all-dups, and sort styles as for the _history_complete_word bindable com‐
mand, see the section `Bindable Commands' below and the section `Completion System
Configuration' above.

_ignored
The ignored-patterns style can be set to a list of patterns which are compared against
possible completions; matching ones are removed. With this completer those matches
can be reinstated, as if no ignored-patterns style were set. The completer actually
generates its own list of matches; which completers are invoked is determined in the
same way as for the _prefix completer. The single-ignored style is also available as
described above.

_list This completer allows the insertion of matches to be delayed until completion is at‐
tempted a second time without the word on the line being changed. On the first at‐
tempt, only the list of matches will be shown. It is affected by the styles condition
and word, see the section `Completion System Configuration' above.

_match This completer is intended to be used after the _complete completer. It behaves simi‐
larly but the string on the command line may be a pattern to match against trial com‐
pletions. This gives the effect of the GLOB_COMPLETE option.

Normally completion will be performed by taking the pattern from the line, inserting a
`*' at the cursor position and comparing the resulting pattern with the possible com‐
pletions generated. This can be modified with the match-original style described
above.

The generated matches will be offered in a menu completion unless the insert-unambigu‐‐
ous style is set to `true'; see the description above for other options for this
style.

Note that matcher specifications defined globally or used by the completion functions
(the styles matcher-list and matcher) will not be used.

_menu This completer was written as simple example function to show how menu completion can
be enabled in shell code. However, it has the notable effect of disabling menu selec‐
tion which can be useful with _generic based widgets. It should be used as the first
completer in the list. Note that this is independent of the setting of the MENU_COM‐‐
PLETE option and does not work with the other menu completion widgets such as re‐‐
verse-menu-complete, or accept-and-menu-complete.

_oldlist
This completer controls how the standard completion widgets behave when there is an
existing list of completions which may have been generated by a special completion
(i.e. a separately-bound completion command). It allows the ordinary completion keys
to continue to use the list of completions thus generated, instead of producing a new
list of ordinary contextual completions. It should appear in the list of completers
before any of the widgets which generate matches. It uses two styles: old-list and
old-menu, see the section `Completion System Configuration' above.

_precommand
Complete an external command in word-separated arguments, as for exec and
/usr/bin/env.

_prefix
This completer can be used to try completion with the suffix (everything after the
cursor) ignored. In other words, the suffix will not be considered to be part of the
word to complete. The effect is similar to the expand-or-complete-prefix command.

The completer style is used to decide which other completers are to be called to gen‐
erate matches. If this style is unset, the list of completers set for the current
context is used -- except, of course, the _prefix completer itself. Furthermore, if
this completer appears more than once in the list of completers only those completers
not already tried by the last invocation of _prefix will be called.

For example, consider this global completer style:

zstyle ':completion:*' completer \
_complete _prefix _correct _prefix:foo

Here, the _prefix completer tries normal completion but ignoring the suffix. If that
doesn't generate any matches, and neither does the call to the _correct completer af‐
ter it, _prefix will be called a second time and, now only trying correction with the
suffix ignored. On the second invocation the completer part of the context appears as
`foo'.

To use _prefix as the last resort and try only normal completion when it is invoked:

zstyle ':completion:*' completer _complete ... _prefix
zstyle ':completion::prefix:*' completer _complete

The add-space style is also respected. If it is set to `true' then _prefix will in‐
sert a space between the matches generated (if any) and the suffix.

Note that this completer is only useful if the COMPLETE_IN_WORD option is set; other‐
wise, the cursor will be moved to the end of the current word before the completion
code is called and hence there will be no suffix.

_user_expand
This completer behaves similarly to the _expand completer but instead performs expan‐
sions defined by users. The styles add-space and sort styles specific to the _expand
completer are usable with _user_expand in addition to other styles handled more gener‐
ally by the completion system. The tag all-expansions is also available.

The expansion depends on the array style user-expand being defined for the current
context; remember that the context for completers is less specific than that for con‐
textual completion as the full context has not yet been determined. Elements of the
array may have one of the following forms:

$hash

hash is the name of an associative array. Note this is not a full parameter
expression, merely a $, suitably quoted to prevent immediate expansion, fol‐
lowed by the name of an associative array. If the trial expansion word matches
a key in hash, the resulting expansion is the corresponding value.
_func

_func is the name of a shell function whose name must begin with _ but is not
otherwise special to the completion system. The function is called with the
trial word as an argument. If the word is to be expanded, the function should
set the array reply to a list of expansions. Optionally, it can set REPLY to a
word that will be used as a description for the set of expansions. The return
status of the function is irrelevant.
BINDABLE COMMANDS
In addition to the context-dependent completions provided, which are expected to work in an
intuitively obvious way, there are a few widgets implementing special behaviour which can be
bound separately to keys. The following is a list of these and their default bindings.

_bash_completions
This function is used by two widgets, _bash_complete-word and _bash_list-choices. It
exists to provide compatibility with completion bindings in bash. The last character
of the binding determines what is completed: `!', command names; `$', environment
variables; `@', host names; `/', file names; `~' user names. In bash, the binding
preceded by `\e' gives completion, and preceded by `^X' lists options. As some of
these bindings clash with standard zsh bindings, only `\e~' and `^X~' are bound by de‐
fault. To add the rest, the following should be added to .zshrc after compinit has
been run:

for key in '!' '$' '@' '/' '~'; do
bindkey "\e$key" _bash_complete-word
bindkey "^X$key" _bash_list-choices
done

This includes the bindings for `~' in case they were already bound to something else;
the completion code does not override user bindings.

_correct_filename (^XC)
Correct the filename path at the cursor position. Allows up to six errors in the
name. Can also be called with an argument to correct a filename path, independently
of zle; the correction is printed on standard output.

_correct_word (^Xc)
Performs correction of the current argument using the usual contextual completions as
possible choices. This stores the string `correct-word' in the function field of the
context name and then calls the _correct completer.

_expand_alias (^Xa)
This function can be used as a completer and as a bindable command. It expands the
word the cursor is on if it is an alias. The types of alias expanded can be con‐
trolled with the styles regular, global and disabled.

When used as a bindable command there is one additional feature that can be selected
by setting the complete style to `true'. In this case, if the word is not the name of
an alias, _expand_alias tries to complete the word to a full alias name without ex‐
panding it. It leaves the cursor directly after the completed word so that invoking
_expand_alias once more will expand the now-complete alias name.

_expand_word (^Xe)
Performs expansion on the current word: equivalent to the standard expand-word com‐
mand, but using the _expand completer. Before calling it, the function field of the
context is set to `expand-word'.

_generic
This function is not defined as a widget and not bound by default. However, it can be
used to define a widget and will then store the name of the widget in the function
field of the context and call the completion system. This allows custom completion
widgets with their own set of style settings to be defined easily. For example, to
define a widget that performs normal completion and starts menu selection:

zle -C foo complete-word _generic
bindkey '...' foo
zstyle ':completion:foo:*' menu yes select=1

Note in particular that the completer style may be set for the context in order to
change the set of functions used to generate possible matches. If _generic is called
with arguments, those are passed through to _main_complete as the list of completers
in place of those defined by the completer style.

_history_complete_word (\e/)
Complete words from the shell's command history. This uses the list, remove-all-dups,
sort, and stop styles.

_most_recent_file (^Xm)
Complete the name of the most recently modified file matching the pattern on the com‐
mand line (which may be blank). If given a numeric argument N, complete the Nth most
recently modified file. Note the completion, if any, is always unique.

_next_tags (^Xn)
This command alters the set of matches used to that for the next tag, or set of tags,
either as given by the tag-order style or as set by default; these matches would oth‐
erwise not be available. Successive invocations of the command cycle through all pos‐
sible sets of tags.

_read_comp (^X^R)
Prompt the user for a string, and use that to perform completion on the current word.
There are two possibilities for the string. First, it can be a set of words beginning
`_', for example `_files -/', in which case the function with any arguments will be
called to generate the completions. Unambiguous parts of the function name will be
completed automatically (normal completion is not available at this point) until a
space is typed.

Second, any other string will be passed as a set of arguments to compadd and should
hence be an expression specifying what should be completed.

A very restricted set of editing commands is available when reading the string: `DEL'
and `^H' delete the last character; `^U' deletes the line, and `^C' and `^G' abort the
function, while `RET' accepts the completion. Note the string is used verbatim as a
command line, so arguments must be quoted in accordance with standard shell rules.

Once a string has been read, the next call to _read_comp will use the existing string
instead of reading a new one. To force a new string to be read, call _read_comp with
a numeric argument.

_complete_debug (^X?)
This widget performs ordinary completion, but captures in a temporary file a trace of
the shell commands executed by the completion system. Each completion attempt gets
its own file. A command to view each of these files is pushed onto the editor buffer
stack.

_complete_help (^Xh)
This widget displays information about the context names, the tags, and the completion
functions used when completing at the current cursor position. If given a numeric ar‐
gument other than 1 (as in `ESC-2 ^Xh'), then the styles used and the contexts for
which they are used will be shown, too.

Note that the information about styles may be incomplete; it depends on the informa‐
tion available from the completion functions called, which in turn is determined by
the user's own styles and other settings.

_complete_help_generic
Unlike other commands listed here, this must be created as a normal ZLE widget rather
than a completion widget (i.e. with zle -N). It is used for generating help with a
widget bound to the _generic widget that is described above.

If this widget is created using the name of the function, as it is by default, then
when executed it will read a key sequence. This is expected to be bound to a call to
a completion function that uses the _generic widget. That widget will be executed,
and information provided in the same format that the _complete_help widget displays
for contextual completion.

If the widget's name contains debug, for example if it is created as `zle -N _com‐‐
plete_debug_generic _complete_help_generic', it will read and execute the keystring
for a generic widget as before, but then generate debugging information as done by
_complete_debug for contextual completion.

If the widget's name contains noread, it will not read a keystring but instead arrange
that the next use of a generic widget run in the same shell will have the effect as
described above.

The widget works by setting the shell parameter ZSH_TRACE_GENERIC_WIDGET which is read
by _generic. Unsetting the parameter cancels any pending effect of the noread form.

For example, after executing the following:

zle -N _complete_debug_generic _complete_help_generic
bindkey '^x:' _complete_debug_generic

typing `C-x :' followed by the key sequence for a generic widget will cause trace out‐
put for that widget to be saved to a file.

_complete_tag (^Xt)
This widget completes symbol tags created by the etags or ctags programmes (note there
is no connection with the completion system's tags) stored in a file TAGS, in the for‐
mat used by etags, or tags, in the format created by ctags. It will look back up the
path hierarchy for the first occurrence of either file; if both exist, the file TAGS
is preferred. You can specify the full path to a TAGS or tags file by setting the pa‐
rameter $TAGSFILE or $tagsfile respectively. The corresponding completion tags used
are etags and vtags, after emacs and vi respectively.

UTILITY FUNCTIONS
Descriptions follow for utility functions that may be useful when writing completion func‐
tions. If functions are installed in subdirectories, most of these reside in the Base subdi‐
rectory. Like the example functions for commands in the distribution, the utility functions
generating matches all follow the convention of returning status zero if they generated com‐
pletions and non-zero if no matching completions could be added.

_absolute_command_paths
This function completes external commands as absolute paths (unlike _command_names -e
which completes their basenames). It takes no arguments.

_all_labels [ -x ] [ -12VJ ] tag name descr [ command arg ... ]
This is a convenient interface to the _next_label function below, implementing the
loop shown in the _next_label example. The command and its arguments are called to
generate the matches. The options stored in the parameter name will automatically be
inserted into the args passed to the command. Normally, they are put directly after
the command, but if one of the args is a single hyphen, they are inserted directly be‐
fore that. If the hyphen is the last argument, it will be removed from the argument
list before the command is called. This allows _all_labels to be used in almost all
cases where the matches can be generated by a single call to the compadd builtin com‐
mand or by a call to one of the utility functions.

For example:

local expl
...
if _requested foo; then
...
_all_labels foo expl '...' compadd ... - $matches
fi

Will complete the strings from the matches parameter, using compadd with additional
options which will take precedence over those generated by _all_labels.

_alternative [ -O name ] [ -C name ] spec ...
This function is useful in simple cases where multiple tags are available. Essen‐
tially it implements a loop like the one described for the _tags function below.

The tags to use and the action to perform if a tag is requested are described using
the specs which are of the form: `tag:descr:action'. The tags are offered using _tags
and if the tag is requested, the action is executed with the given description descr.
The actions are those accepted by the _arguments function (described below), excluding
the `->state' and `=...' forms.

For example, the action may be a simple function call:

_alternative \
'users:user:_users' \
'hosts:host:_hosts'

offers usernames and hostnames as possible matches, generated by the _users and _hosts
functions respectively.

Like _arguments, this function uses _all_labels to execute the actions, which will
loop over all sets of tags. Special handling is only required if there is an addi‐
tional valid tag, for example inside a function called from _alternative.

The option `-O name' is used in the same way as by the _arguments function. In other
words, the elements of the name array will be passed to compadd when executing an ac‐
tion.

Like _tags this function supports the -C option to give a different name for the argu‐
ment context field.

_arguments [ -nswWCRS ] [ -A pat ] [ -O name ] [ -M matchspec ]
[ : ] spec ...
_arguments [ opt ... ] -- [ -l ] [ -i pats ] [ -s pair ]
[ helpspec ...]
This function can be used to give a complete specification for completion for a com‐
mand whose arguments follow standard UNIX option and argument conventions.

Options Overview

Options to _arguments itself must be in separate words, i.e. -s -w, not -sw. The op‐
tions are followed by specs that describe options and arguments of the analyzed com‐
mand. To avoid ambiguity, all options to _arguments itself may be separated from the
spec forms by a single colon.

The `--' form is used to intuit spec forms from the help output of the command being
analyzed, and is described in detail below. The opts for the `--' form are otherwise
the same options as the first form. Note that `-s' following `--' has a distinct
meaning from `-s' preceding `--', and both may appear.

The option switches -s, -S, -A, -w, and -W affect how _arguments parses the analyzed
command line's options. These switches are useful for commands with standard argument
parsing.

The options of _arguments have the following meanings:

-n With this option, _arguments sets the parameter NORMARG to the position of the
first normal argument in the $words array, i.e. the position after the end of
the options. If that argument has not been reached, NORMARG is set to -1. The
caller should declare `integer NORMARG' if the -n option is passed; otherwise
the parameter is not used.

-s Enable option stacking for single-letter options, whereby multiple single-let‐
ter options may be combined into a single word. For example, the two options
`-x' and `-y' may be combined into a single word `-xy'. By default, every word
corresponds to a single option name (`-xy' is a single option named `xy').

Options beginning with a single hyphen or plus sign are eligible for stacking;
words beginning with two hyphens are not.

Note that -s after -- has a different meaning, which is documented in the seg‐
ment entitled `Deriving spec forms from the help output'.

-w In combination with -s, allow option stacking even if one or more of the op‐
tions take arguments. For example, if -x takes an argument, with no -s, `-xy'
is considered as a single (unhandled) option; with -s, -xy is an option with
the argument `y'; with both -s and -w, -xy is the option -x and the option -y
with arguments to -x (and to -y, if it takes arguments) still to come in subse‐
quent words.

-W This option takes -w a stage further: it is possible to complete single-letter
options even after an argument that occurs in the same word. However, it de‐
pends on the action performed whether options will really be completed at this
point. For more control, use a utility function like _guard as part of the ac‐
tion.

-C Modify the curcontext parameter for an action of the form `->state'. This is
discussed in detail below.

-R Return status 300 instead of zero when a $state is to be handled, in the
`->string' syntax.

-S Do not complete options after a `--' appearing on the line, and ignore the
`--'. For example, with -S, in the line

foobar -x -- -y

the `-x' is considered an option, the `-y' is considered an argument, and the
`--' is considered to be neither.

-A pat Do not complete options after the first non-option argument on the line. pat
is a pattern matching all strings which are not to be taken as arguments. For
example, to make _arguments stop completing options after the first normal ar‐
gument, but ignoring all strings starting with a hyphen even if they are not
described by one of the optspecs, the form is `-A "-*"'.

-O name
Pass the elements of the array name as arguments to functions called to execute
actions. This is discussed in detail below.

-M matchspec
Use the match specification matchspec for completing option names and values.
The default matchspec allows partial word completion after `_' and `-', such as
completing `-f-b' to `-foo-bar'. The default matchspec is:
r:|[_-]=* r:|=*

specs: overview

Each of the following forms is a spec describing individual sets of options or argu‐
ments on the command line being analyzed.

n:message:action
n::message:action
This describes the n'th normal argument. The message will be printed above the
matches generated and the action indicates what can be completed in this posi‐
tion (see below). If there are two colons before the message the argument is
optional. If the message contains only white space, nothing will be printed
above the matches unless the action adds an explanation string itself.

:message:action
::message:action
Similar, but describes the next argument, whatever number that happens to be.
If all arguments are specified in this form in the correct order the numbers
are unnecessary.

*:message:action
*::message:action
*:::message:action
This describes how arguments (usually non-option arguments, those not beginning
with - or +) are to be completed when neither of the first two forms was pro‐
vided. Any number of arguments can be completed in this fashion.

With two colons before the message, the words special array and the CURRENT
special parameter are modified to refer only to the normal arguments when the
action is executed or evaluated. With three colons before the message they are
modified to refer only to the normal arguments covered by this description.

optspec
optspec:...
This describes an option. The colon indicates handling for one or more argu‐
ments to the option; if it is not present, the option is assumed to take no ar‐
guments.

The following forms are available for the initial optspec, whether or not the
option has arguments.

*optspec
Here optspec is one of the remaining forms below. This indicates the
following optspec may be repeated. Otherwise if the corresponding op‐
tion is already present on the command line to the left of the cursor it
will not be offered again.

-optname
+optname
In the simplest form the optspec is just the option name beginning with
a minus or a plus sign, such as `-foo'. The first argument for the op‐
tion (if any) must follow as a separate word directly after the option.

Either of `-+optname' and `+-optname' can be used to specify that -opt‐
name and +optname are both valid.

In all the remaining forms, the leading `-' may be replaced by or paired
with `+' in this way.

-optname-
The first argument of the option must come directly after the option
name in the same word. For example, `-foo-:...' specifies that the com‐
pleted option and argument will look like `-fooarg'.

-optname+
The first argument may appear immediately after optname in the same
word, or may appear as a separate word after the option. For example,
`-foo+:...' specifies that the completed option and argument will look
like either `-fooarg' or `-foo arg'.

-optname=
The argument may appear as the next word, or in same word as the option
name provided that it is separated from it by an equals sign, for exam‐
ple `-foo=arg' or `-foo arg'.

-optname=-
The argument to the option must appear after an equals sign in the same
word, and may not be given in the next argument.

optspec[explanation]
An explanation string may be appended to any of the preceding forms of
optspec by enclosing it in brackets, as in `-q[query operation]'.

The verbose style is used to decide whether the explanation strings are
displayed with the option in a completion listing.

If no bracketed explanation string is given but the auto-description
style is set and only one argument is described for this optspec, the
value of the style is displayed, with any appearance of the sequence
`%d' in it replaced by the message of the first optarg that follows the
optspec; see below.

It is possible for options with a literal `+' or `=' to appear, but that char‐
acter must be quoted, for example `-\+'.

Each optarg following an optspec must take one of the following forms:

:message:action
::message:action
An argument to the option; message and action are treated as for ordi‐
nary arguments. In the first form, the argument is mandatory, and in
the second form it is optional.

This group may be repeated for options which take multiple arguments.
In other words, :message1:action1:message2:action2 specifies that the
option takes two arguments.

:*pattern:message:action
:*pattern::message:action
:*pattern:::message:action
This describes multiple arguments. Only the last optarg for an option
taking multiple arguments may be given in this form. If the pattern is
empty (i.e. :*:), all the remaining words on the line are to be com‐
pleted as described by the action; otherwise, all the words up to and
including a word matching the pattern are to be completed using the ac‐
tion.

Multiple colons are treated as for the `*:...' forms for ordinary argu‐
ments: when the message is preceded by two colons, the words special
array and the CURRENT special parameter are modified during the execu‐
tion or evaluation of the action to refer only to the words after the
option. When preceded by three colons, they are modified to refer only
to the words covered by this description.

Any literal colon in an optname, message, or action must be preceded by a backslash,
`\:'.

Each of the forms above may be preceded by a list in parentheses of option names and
argument numbers. If the given option is on the command line, the options and argu‐
ments indicated in parentheses will not be offered. For example, `(-two -three
1)-one:...' completes the option `-one'; if this appears on the command line, the op‐
tions -two and -three and the first ordinary argument will not be completed after it.
`(-foo):...' specifies an ordinary argument completion; -foo will not be completed if
that argument is already present.

Other items may appear in the list of excluded options to indicate various other items
that should not be applied when the current specification is matched: a single star
(*) for the rest arguments (i.e. a specification of the form `*:...'); a colon (:) for
all normal (non-option-) arguments; and a hyphen (-) for all options. For example, if
`(*)' appears before an option and the option appears on the command line, the list of
remaining arguments (those shown in the above table beginning with `*:') will not be
completed.

To aid in reuse of specifications, it is possible to precede any of the forms above
with `!'; then the form will no longer be completed, although if the option or argu‐
ment appears on the command line they will be skipped as normal. The main use for
this is when the arguments are given by an array, and _arguments is called repeatedly
for more specific contexts: on the first call `_arguments $global_options' is used,
and on subsequent calls `_arguments !$^global_options'.

specs: actions

In each of the forms above the action determines how completions should be generated.
Except for the `->string' form below, the action will be executed by calling the
_all_labels function to process all tag labels. No special handling of tags is needed
unless a function call introduces a new one.

The functions called to execute actions will be called with the elements of the array
named by the `-O name' option as arguments. This can be used, for example, to pass
the same set of options for the compadd builtin to all actions.

The forms for action are as follows.

(single unquoted space)
This is useful where an argument is required but it is not possible or desir‐
able to generate matches for it. The message will be displayed but no comple‐
tions listed. Note that even in this case the colon at the end of the message
is needed; it may only be omitted when neither a message nor an action is
given.

(item1 item2 ...)
One of a list of possible matches, for example:

:foo:(foo bar baz)

((item1\:desc1 ...))
Similar to the above, but with descriptions for each possible match. Note the
backslash before the colon. For example,

:foo:((a\:bar b\:baz))

The matches will be listed together with their descriptions if the description
style is set with the values tag in the context.

->string
In this form, _arguments processes the arguments and options and then returns
control to the calling function with parameters set to indicate the state of
processing; the calling function then makes its own arrangements for generating
completions. For example, functions that implement a state machine can use
this type of action.

Where _arguments encounters action in the `->string' format, it will strip all
leading and trailing whitespace from string and set the array state to the set
of all strings for which an action is to be performed. The elements of the ar‐
ray state_descr are assigned the corresponding message field from each optarg
containing such an action.

By default and in common with all other well behaved completion functions, _ar‐
guments returns status zero if it was able to add matches and non-zero other‐
wise. However, if the -R option is given, _arguments will instead return a sta‐
tus of 300 to indicate that $state is to be handled.

In addition to $state and $state_descr, _arguments also sets the global parame‐
ters `context', `line' and `opt_args' as described below, and does not reset
any changes made to the special parameters such as PREFIX and words. This
gives the calling function the choice of resetting these parameters or propa‐
gating changes in them.

A function calling _arguments with at least one action containing a `->string'
must therefore declare appropriate local parameters:

local context state state_descr line
typeset -A opt_args

to prevent _arguments from altering the global environment.

{eval-string}
A string in braces is evaluated as shell code to generate matches. If the
eval-string itself does not begin with an opening parenthesis or brace it is
split into separate words before execution.

= action
If the action starts with `= ' (an equals sign followed by a space), _arguments
will insert the contents of the argument field of the current context as the
new first element in the words special array and increment the value of the
CURRENT special parameter. This has the effect of inserting a dummy word onto
the completion command line while not changing the point at which completion is
taking place.

This is most useful with one of the specifiers that restrict the words on the
command line on which the action is to operate (the two- and three-colon forms
above). One particular use is when an action itself causes _arguments on a re‐
stricted range; it is necessary to use this trick to insert an appropriate com‐
mand name into the range for the second call to _arguments to be able to parse
the line.

word...
word...
This covers all forms other than those above. If the action starts with a
space, the remaining list of words will be invoked unchanged.

Otherwise it will be invoked with some extra strings placed after the first
word; these are to be passed down as options to the compadd builtin. They en‐
sure that the state specified by _arguments, in particular the descriptions of
options and arguments, is correctly passed to the completion command. These
additional arguments are taken from the array parameter `expl'; this will be
set up before executing the action and hence may be referred to inside it, typ‐
ically in an expansion of the form `$expl[@]' which preserves empty elements of
the array.

During the performance of the action the array `line' will be set to the normal argu‐
ments from the command line, i.e. the words from the command line after the command
name excluding all options and their arguments. Options are stored in the associative
array `opt_args' with option names as keys and their arguments as the values. For op‐
tions that have more than one argument these are given as one string, separated by
colons. All colons and backslashes in the original arguments are preceded with back‐
slashes.

The parameter `context' is set when returning to the calling function to perform an
action of the form `->string'. It is set to an array of elements corresponding to the
elements of $state. Each element is a suitable name for the argument field of the
context: either a string of the form `option-opt-n' for the n'th argument of the op‐
tion -opt, or a string of the form `argument-n' for the n'th argument. For `rest' ar‐
guments, that is those in the list at the end not handled by position, n is the string
`rest'. For example, when completing the argument of the -o option, the name is `op‐‐
tion-o-1', while for the second normal (non-option-) argument it is `argument-2'.

Furthermore, during the evaluation of the action the context name in the curcontext
parameter is altered to append the same string that is stored in the context parame‐
ter.

The option -C tells _arguments to modify the curcontext parameter for an action of the
form `->state'. This is the standard parameter used to keep track of the current con‐
text. Here it (and not the context array) should be made local to the calling func‐
tion to avoid passing back the modified value and should be initialised to the current
value at the start of the function:

local curcontext="$curcontext"

This is useful where it is not possible for multiple states to be valid together.

Grouping Options

Options can be grouped to simplify exclusion lists. A group is introduced with `+'
followed by a name for the group in the subsequent word. Whole groups can then be ref‐
erenced in an exclusion list or a group name can be used to disambiguate between two
forms of the same option. For example:

_arguments \
'(group2--x)-a' \
+ group1 \
-m \
'(group2)-n' \
+ group2 \
-x -y

If the name of a group is specified in the form `(name)' then only one value from that
group will ever be completed; more formally, all specifications are mutually exclusive
to all other specifications in that group. This is useful for defining options that
are aliases for each other. For example:

_arguments \
-a -b \
+ '(operation)' \
{-c,--compress}'[compress]' \
{-d,--decompress}'[decompress]' \
{-l,--list}'[list]'

If an option in a group appears on the command line, it is stored in the associative
array `opt_args' with 'group-option' as a key. In the example above, a key `opera‐‐
tion--c' is used if the option `-c' is present on the command line.

Specifying Multiple Sets of Arguments

It is possible to specify multiple sets of options and arguments with the sets sepa‐
rated by single hyphens. This differs from groups in that sets are considered to be
mutually exclusive of each other.

Specifications before the first set and from any group are common to all sets. For ex‐
ample:

_arguments \
-a \
- set1 \
-c \
- set2 \
-d \
':arg:(x2 y2)'

This defines two sets. When the command line contains the option `-c', the `-d' op‐
tion and the argument will not be considered possible completions. When it contains
`-d' or an argument, the option `-c' will not be considered. However, after `-a' both
sets will still be considered valid.

As for groups, the name of a set may appear in exclusion lists, either alone or pre‐
ceding a normal option or argument specification.

The completion code has to parse the command line separately for each set. This can be
slow so sets should only be used when necessary. A useful alternative is often an op‐
tion specification with rest-arguments (as in `-foo:*:...'); here the option -foo
swallows up all remaining arguments as described by the optarg definitions.

Deriving spec forms from the help output

The option `--' allows _arguments to work out the names of long options that support
the `--help' option which is standard in many GNU commands. The command word is
called with the argument `--help' and the output examined for option names. Clearly,
it can be dangerous to pass this to commands which may not support this option as the
behaviour of the command is unspecified.

In addition to options, `_arguments --' will try to deduce the types of arguments
available for options when the form `--opt=val' is valid. It is also possible to pro‐
vide hints by examining the help text of the command and adding helpspec of the form
`pattern:message:action'; note that other _arguments spec forms are not used. The
pattern is matched against the help text for an option, and if it matches the message
and action are used as for other argument specifiers. The special case of `*:' means
both message and action are empty, which has the effect of causing options having no
description in the help output to be ordered in listings ahead of options that have a
description.

For example:

_arguments -- '*\*:toggle:(yes no)' \
'*=FILE*:file:_files' \
'*=DIR*:directory:_files -/' \
'*=PATH*:directory:_files -/'

Here, `yes' and `no' will be completed as the argument of options whose description
ends in a star; file names will be completed for options that contain the substring
`=FILE' in the description; and directories will be completed for options whose de‐
scription contains `=DIR' or `=PATH'. The last three are in fact the default and so
need not be given explicitly, although it is possible to override the use of these
patterns. A typical help text which uses this feature is:

-C, --directory=DIR change to directory DIR

so that the above specifications will cause directories to be completed after `--di‐‐
rectory', though not after `-C'.

Note also that _arguments tries to find out automatically if the argument for an op‐
tion is optional. This can be specified explicitly by doubling the colon before the
message.

If the pattern ends in `(-)', this will be removed from the pattern and the action
will be used only directly after the `=', not in the next word. This is the behaviour
of a normal specification defined with the form `=-'.

By default, the command (with the option `--help') is run after resetting all the lo‐
cale categories (except for LC_CTYPE) to `C'. If the localized help output is known
to work, the option `-l' can be specified after the `_arguments --' so that the com‐
mand is run in the current locale.

The `_arguments --' can be followed by the option `-i patterns' to give patterns for
options which are not to be completed. The patterns can be given as the name of an
array parameter or as a literal list in parentheses. For example,

_arguments -- -i \
"(--(en|dis)able-FEATURE*)"

will cause completion to ignore the options `--enable-FEATURE' and `--disable-FEATURE'
(this example is useful with GNU configure).

The `_arguments --' form can also be followed by the option `-s pair' to describe op‐
tion aliases. The pair consists of a list of alternating patterns and corresponding
replacements, enclosed in parens and quoted so that it forms a single argument word in
the _arguments call.

For example, some configure-script help output describes options only as `--en‐‐
able-foo', but the script also accepts the negated form `--disable-foo'. To allow
completion of the second form:

_arguments -- -s "((#s)--enable- --disable-)"

Miscellaneous notes

Finally, note that _arguments generally expects to be the primary function handling
any completion for which it is used. It may have side effects which change the treat‐
ment of any matches added by other functions called after it. To combine _arguments
with other functions, those functions should be called either before _arguments, as an
action within a spec, or in handlers for `->state' actions.

Here is a more general example of the use of _arguments:

_arguments '-l+:left border:' \
'-format:paper size:(letter A4)' \
'*-copy:output file:_files::resolution:(300 600)' \
':postscript file:_files -g \*.$ps\|eps$' \
'*:page number:'

This describes three options: `-l', `-format', and `-copy'. The first takes one argu‐
ment described as `left border' for which no completion will be offered because of the
empty action. Its argument may come directly after the `-l' or it may be given as the
next word on the line.

The `-format' option takes one argument in the next word, described as `paper size'
for which only the strings `letter' and `A4' will be completed.

The `-copy' option may appear more than once on the command line and takes two argu‐
ments. The first is mandatory and will be completed as a filename. The second is op‐
tional (because of the second colon before the description `resolution') and will be
completed from the strings `300' and `600'.

The last two descriptions say what should be completed as arguments. The first de‐
scribes the first argument as a `postscript file' and makes files ending in `ps' or
`eps' be completed. The last description gives all other arguments the description
`page numbers' but does not offer completions.

_cache_invalid cache_identifier
This function returns status zero if the completions cache corresponding to the given
cache identifier needs rebuilding. It determines this by looking up the cache-policy
style for the current context. This should provide a function name which is run with
the full path to the relevant cache file as the only argument.

Example:

_example_caching_policy () {
# rebuild if cache is more than a week old
local -a oldp
oldp=( "$1"(Nm+7) )
(( $#oldp ))
}

_call_function return name [ arg ... ]
If a function name exists, it is called with the arguments args. The return argument
gives the name of a parameter in which the return status from the function name should
be stored; if return is empty or a single hyphen it is ignored.

The return status of _call_function itself is zero if the function name exists and was
called and non-zero otherwise.

_call_program [ -l ] [ -p ] tag string ...
This function provides a mechanism for the user to override the use of an external
command. It looks up the command style with the supplied tag. If the style is set,
its value is used as the command to execute. The strings from the call to _call_pro‐‐
gram, or from the style if set, are concatenated with spaces between them and the re‐
sulting string is evaluated. The return status is the return status of the command
called.

By default, the command is run in an environment where all the locale categories (ex‐
cept for LC_CTYPE) are reset to `C' by calling the utility function _comp_locale (see
below). If the option `-l' is given, the command is run with the current locale.

If the option `-p' is supplied it indicates that the command output is influenced by
the permissions it is run with. If the gain-privileges style is set to true,
_call_program will make use of commands such as sudo, if present on the command-line,
to match the permissions to whatever the final command is likely to run under. When
looking up the gain-privileges and command styles, the command component of the zstyle
context will end with a slash (`/') followed by the command that would be used to gain
privileges.

_combination [ -s pattern ] tag style spec ... field opts ...
This function is used to complete combinations of values, for example pairs of host‐
names and usernames. The style argument gives the style which defines the pairs; it
is looked up in a context with the tag specified.

The style name consists of field names separated by hyphens, for example
`users-hosts-ports'. For each field for a value is already known, a spec of the form
`field=pattern' is given. For example, if the command line so far specifies a user
`pws', the argument `users=pws' should appear.

The next argument with no equals sign is taken as the name of the field for which com‐
pletions should be generated (presumably not one of the fields for which the value is
known).

The matches generated will be taken from the value of the style. These should contain
the possible values for the combinations in the appropriate order (users, hosts, ports
in the example above). The values for the different fields are separated by colons.
This can be altered with the option -s to _combination which specifies a pattern.
Typically this is a character class, as for example `-s "[:@]"' in the case of the
users-hosts style. Each `field=pattern' specification restricts the completions
which apply to elements of the style with appropriately matching fields.

If no style with the given name is defined for the given tag, or if none of the
strings in style's value match, but a function name of the required field preceded by
an underscore is defined, that function will be called to generate the matches. For
example, if there is no `users-hosts-ports' or no matching hostname when a host is re‐
quired, the function `_hosts' will automatically be called.

If the same name is used for more than one field, in both the `field=pattern' and the
argument that gives the name of the field to be completed, the number of the field
(starting with one) may be given after the fieldname, separated from it by a colon.

All arguments after the required field name are passed to compadd when generating
matches from the style value, or to the functions for the fields if they are called.

_command_names [ -e | - ]
This function completes words that are valid at command position: names of aliases,
builtins, hashed commands, functions, and so on. With the -e flag, only hashed com‐
mands are completed. The - flag is ignored.

_comp_locale
This function resets all the locale categories other than LC_CTYPE to `C' so that the
output from external commands can be easily analyzed by the completion system.
LC_CTYPE retains the current value (taking LC_ALL and LANG into account), ensuring
that non-ASCII characters in file names are still handled properly.

This function should normally be run only in a subshell, because the new locale is ex‐
ported to the environment. Typical usage would be `$(_comp_locale; command ...)'.

_completers [ -p ]
This function completes names of completers.

-p Include the leading underscore (`_') in the matches.

_describe [-12JVx] [ -oO | -t tag ] descr name1 [ name2 ] [ opt ... ]
[ -- name1 [ name2 ] [ opt ... ] ... ]
This function associates completions with descriptions. Multiple groups separated by
-- can be supplied, potentially with different completion options opts.

The descr is taken as a string to display above the matches if the format style for
the descriptions tag is set. This is followed by one or two names of arrays followed
by options to pass to compadd. The array name1 contains the possible completions with
their descriptions in the form `completion:description'. Any literal colons in com‐
pletion must be quoted with a backslash. If a name2 is given, it should have the same
number of elements as name1; in this case the corresponding elements are added as pos‐
sible completions instead of the completion strings from name1. The completion list
will retain the descriptions from name1. Finally, a set of completion options can ap‐
pear.

If the option `-o' appears before the first argument, the matches added will be
treated as names of command options (N.B. not shell options), typically following a
`-', `--' or `+' on the command line. In this case _describe uses the prefix-hidden,
prefix-needed and verbose styles to find out if the strings should be added as comple‐
tions and if the descriptions should be shown. Without the `-o' option, only the ver‐‐
bose style is used to decide how descriptions are shown. If `-O' is used instead of
`-o', command options are completed as above but _describe will not handle the pre‐‐
fix-needed style.

With the -t option a tag can be specified. The default is `values' or, if the -o op‐
tion is given, `options'.

The options -1, -2, -J, -V, -x are passed to _next_label.

If selected by the list-grouped style, strings with the same description will appear
together in the list.

_describe uses the _all_labels function to generate the matches, so it does not need
to appear inside a loop over tag labels.

_description [ -x ] [ -12VJ ] tag name descr [ spec ... ]
This function is not to be confused with the previous one; it is used as a helper
function for creating options to compadd. It is buried inside many of the higher
level completion functions and so often does not need to be called directly.

The styles listed below are tested in the current context using the given tag. The
resulting options for compadd are put into the array named name (this is traditionally
`expl', but this convention is not enforced). The description for the corresponding
set of matches is passed to the function in descr.

The styles tested are: format, hidden, matcher, ignore-line, ignored-patterns,
group-name and sort. The format style is first tested for the given tag and then for
the descriptions tag if no value was found, while the remainder are only tested for
the tag given as the first argument. The function also calls _setup which tests some
more styles.

The string returned by the format style (if any) will be modified so that the sequence
`%d' is replaced by the descr given as the third argument without any leading or
trailing white space. If, after removing the white space, the descr is the empty
string, the format style will not be used and the options put into the name array will
not contain an explanation string to be displayed above the matches.

If _description is called with more than three arguments, the additional specs should
be of the form `char:str'. These supply escape sequence replacements for the format
style: every appearance of `%char' will be replaced by string.

If the -x option is given, the description will be passed to compadd using the -x op‐
tion instead of the default -X. This means that the description will be displayed
even if there are no corresponding matches.

The options placed in the array name take account of the group-name style, so matches
are placed in a separate group where necessary. The group normally has its elements
sorted (by passing the option -J to compadd), but if an option starting with `-V',
`-J', `-1', or `-2' is passed to _description, that option will be included in the ar‐
ray. Hence it is possible for the completion group to be unsorted by giving the op‐
tion `-V', `-1V', or `-2V'.

In most cases, the function will be used like this:

local expl
_description files expl file
compadd "$expl[@]" - "$files[@]"

Note the use of the parameter expl, the hyphen, and the list of matches. Almost all
calls to compadd within the completion system use a similar format; this ensures that
user-specified styles are correctly passed down to the builtins which implement the
internals of completion.

_dir_list [ -s sep ] [ -S ]
Complete a list of directory names separated by colons (the same format as $PATH).

-s sep Use sep as separator between items. sep defaults to a colon (`:').

-S Add sep instead of slash (`/') as an autoremoveable suffix.

_dispatch context string ...
This sets the current context to context and looks for completion functions to handle
this context by hunting through the list of command names or special contexts (as de‐
scribed above for compdef) given as strings. The first completion function to be de‐
fined for one of the contexts in the list is used to generate matches. Typically, the
last string is -default- to cause the function for default completion to be used as a
fallback.

The function sets the parameter $service to the string being tried, and sets the con‐
text/command field (the fourth) of the $curcontext parameter to the context given as
the first argument.

_email_addresses [ -c ] [ -n plugin ]
Complete email addresses. Addresses are provided by plugins.

-c Complete bare localhost AT domain.tld addresses, without a name part or a comment.
Without this option, RFC822 `Firstname Lastname <address>' strings are com‐
pleted.

-n plugin
Complete aliases from plugin.

The following plugins are available by default: _email-ldap (see the filter style),
_email-local (completes user@hostname Unix addresses), _email-mail (completes aliases
from ~/.mailrc), _email-mush, _email-mutt, and _email-pine.

Addresses from the _email-foo plugin are added under the tag `email-foo'.

Writing plugins

Plugins are written as separate functions with names starting with `_email-'. They
are invoked with the -c option and compadd options. They should either do their own
completion or set the $reply array to a list of `alias:address' elements and return
300. New plugins will be picked up and run automatically.

_files The function _files is a wrapper around _path_files. It supports all of the same func‐
tionality, with some enhancements -- notably, it respects the list-dirs-first style,
and it allows users to override the behaviour of the -g and -/ options with the
file-patterns style. _files should therefore be preferred over _path_files in most
cases.

This function accepts the full set of options allowed by _path_files, described below.

_gnu_generic
This function is a simple wrapper around the _arguments function described above. It
can be used to determine automatically the long options understood by commands that
produce a list when passed the option `--help'. It is intended to be used as a
top-level completion function in its own right. For example, to enable option comple‐
tion for the commands foo and bar, use

compdef _gnu_generic foo bar

after the call to compinit.

The completion system as supplied is conservative in its use of this function, since
it is important to be sure the command understands the option `--help'.

_guard [ options ] pattern descr
This function displays descr if pattern matches the string to be completed. It is in‐
tended to be used in the action for the specifications passed to _arguments and simi‐
lar functions.

The return status is zero if the message was displayed and the word to complete is not
empty, and non-zero otherwise.

The pattern may be preceded by any of the options understood by compadd that are
passed down from _description, namely -M, -J, -V, -1, -2, -n, -F and -X. All of these
options will be ignored. This fits in conveniently with the argument-passing conven‐
tions of actions for _arguments.

As an example, consider a command taking the options -n and -none, where -n must be
followed by a numeric value in the same word. By using:

_arguments '-n-: :_guard "[0-9]#" "numeric value"' '-none'

_arguments can be made to both display the message `numeric value' and complete op‐
tions after `-n<TAB>'. If the `-n' is already followed by one or more digits (the
pattern passed to _guard) only the message will be displayed; if the `-n' is followed
by another character, only options are completed.

_message [ -r12 ] [ -VJ group ] descr
_message -e [ tag ] descr
The descr is used in the same way as the third argument to the _description function,
except that the resulting string will always be shown whether or not matches were gen‐
erated. This is useful for displaying a help message in places where no completions
can be generated.

The format style is examined with the messages tag to find a message; the usual tag,
descriptions, is used only if the style is not set with the former.

If the -r option is given, no style is used; the descr is taken literally as the
string to display. This is most useful when the descr comes from a pre-processed ar‐
gument list which already contains an expanded description. Note that this option
does not disable the `%'-sequence parsing done by compadd.

The -12VJ options and the group are passed to compadd and hence determine the group
the message string is added to.

The second -e form gives a description for completions with the tag tag to be shown
even if there are no matches for that tag. This form is called by _arguments in the
event that there is no action for an option specification. The tag can be omitted and
if so the tag is taken from the parameter $curtag; this is maintained by the comple‐
tion system and so is usually correct. Note that if there are no matches at the time
this function is called, compstate[insert] is cleared, so additional matches generated
later are not inserted on the command line.

_multi_parts [ -i ] sep array
The argument sep is a separator character. The array may be either the name of an ar‐
ray parameter or a literal array in the form `(foo bar)', a parenthesised list of
words separated by whitespace. The possible completions are the strings from the ar‐
ray. However, each chunk delimited by sep will be completed separately. For example,
the _tar function uses `_multi_parts / patharray' to complete partial file paths from
the given array of complete file paths.

The -i option causes _multi_parts to insert a unique match even if that requires mul‐
tiple separators to be inserted. This is not usually the expected behaviour with
filenames, but certain other types of completion, for example those with a fixed set
of possibilities, may be more suited to this form.

Like other utility functions, this function accepts the `-V', `-J', `-1', `-2', `-n',
`-f', `-X', `-M', `-P', `-S', `-r', `-R', and `-q' options and passes them to the com‐‐
padd builtin.

_next_label [ -x ] [ -12VJ ] tag name descr [ option ... ]
This function is used to implement the loop over different tag labels for a particular
tag as described above for the tag-order style. On each call it checks to see if
there are any more tag labels; if there is it returns status zero, otherwise non-zero.
As this function requires a current tag to be set, it must always follow a call to
_tags or _requested.

The -x12VJ options and the first three arguments are passed to the _description func‐
tion. Where appropriate the tag will be replaced by a tag label in this call. Any
description given in the tag-order style is preferred to the descr passed to _next_la‐‐
bel.

The options given after the descr are set in the parameter given by name, and hence
are to be passed to compadd or whatever function is called to add the matches.

Here is a typical use of this function for the tag foo. The call to _requested deter‐
mines if tag foo is required at all; the loop over _next_label handles any labels de‐
fined for the tag in the tag-order style.

local expl ret=1
...
if _requested foo; then
...
while _next_label foo expl '...'; do
compadd "$expl[@]" ... && ret=0
done
...
fi
return ret

_normal [ -P | -p precommand ]
This is the standard function called to handle completion outside any special -con‐
text-. It is called both to complete the command word and also the arguments for a
command. In the second case, _normal looks for a special completion for that command,
and if there is none it uses the completion for the -default- context.

A second use is to reexamine the command line specified by the $words array and the
$CURRENT parameter after those have been modified. For example, the function _precom‐‐
mand, which completes after precommand specifiers such as nohup, removes the first
word from the words array, decrements the CURRENT parameter, then calls `_normal -p
$service'. The effect is that `nohup cmd ...' is treated in the same way as `cmd
...'.

-P Reset the list of precommands. This option should be used if completing a com‐
mand line which allows internal commands (e.g. builtins and functions) regard‐
less of prior precommands (e.g. `zsh -c').

-p precommand
Append precommand to the list of precommands. This option should be used in
nearly all cases in which -P is not applicable.

If the command name matches one of the patterns given by one of the options -p or -P
to compdef, the corresponding completion function is called and then the parameter
_compskip is checked. If it is set completion is terminated at that point even if no
matches have been found. This is the same effect as in the -first- context.

_options
This can be used to complete the names of shell options. It provides a matcher speci‐
fication that ignores a leading `no', ignores underscores and allows upper-case let‐
ters to match their lower-case counterparts (for example, `glob', `noglob', `NO_GLOB'
are all completed). Any arguments are propagated to the compadd builtin.

_options_set and _options_unset
These functions complete only set or unset options, with the same matching specifica‐
tion used in the _options function.

Note that you need to uncomment a few lines in the _main_complete function for these
functions to work properly. The lines in question are used to store the option set‐
tings in effect before the completion widget locally sets the options it needs. Hence
these functions are not generally used by the completion system.

_parameters
This is used to complete the names of shell parameters.

The option `-g pattern' limits the completion to parameters whose type matches the
pattern. The type of a parameter is that shown by `print ${(t)param}', hence judi‐
cious use of `*' in pattern is probably necessary.

All other arguments are passed to the compadd builtin.

_path_files
This function is used throughout the completion system to complete filenames. It al‐
lows completion of partial paths. For example, the string `/u/i/s/sig' may be com‐
pleted to `/usr/include/sys/signal.h'.

The options accepted by both _path_files and _files are:

-f Complete all filenames. This is the default.

-/ Specifies that only directories should be completed.

-g pattern
Specifies that only files matching the pattern should be completed.

-W paths
Specifies path prefixes that are to be prepended to the string from the command
line to generate the filenames but that should not be inserted as completions
nor shown in completion listings. Here, paths may be the name of an array pa‐
rameter, a literal list of paths enclosed in parentheses or an absolute path‐
name.

-F ignored-files
This behaves as for the corresponding option to the compadd builtin. It gives
direct control over which filenames should be ignored. If the option is not
present, the ignored-patterns style is used.

Both _path_files and _files also accept the following options which are passed to com‐‐
padd: `-J', `-V', `-1', `-2', `-n', `-X', `-M', `-P', `-S', `-q', `-r', and `-R'.

Finally, the _path_files function uses the styles expand, ambiguous, special-dirs,
list-suffixes and file-sort described above.

_pick_variant [ -b builtin-label ] [ -c command ] [ -r name ]
label=pattern ... label [ arg ... ]
This function is used to resolve situations where a single command name requires more
than one type of handling, either because it has more than one variant or because
there is a name clash between two different commands.

The command to run is taken from the first element of the array words unless this is
overridden by the option -c. This command is run and its output is compared with a
series of patterns. Arguments to be passed to the command can be specified at the end
after all the other arguments. The patterns to try in order are given by the argu‐
ments label=pattern; if the output of `command arg ...' contains pattern, then label
is selected as the label for the command variant. If none of the patterns match, the
final command label is selected and status 1 is returned.

If the `-b builtin-label' is given, the command is tested to see if it is provided as
a shell builtin, possibly autoloaded; if so, the label builtin-label is selected as
the label for the variant.

If the `-r name' is given, the label picked is stored in the parameter named name.

The results are also cached in the _cmd_variant associative array indexed by the name
of the command run.

_regex_arguments name spec ...
This function generates a completion function name which matches the specifications
specs, a set of regular expressions as described below. After running _regex_argu‐‐
ments, the function name should be called as a normal completion function. The pat‐
tern to be matched is given by the contents of the words array up to the current cur‐
sor position joined together with null characters; no quotation is applied.

The arguments are grouped as sets of alternatives separated by `|', which are tried
one after the other until one matches. Each alternative consists of a one or more
specifications which are tried left to right, with each pattern matched being stripped
in turn from the command line being tested, until all of the group succeeds or until
one fails; in the latter case, the next alternative is tried. This structure can be
repeated to arbitrary depth by using parentheses; matching proceeds from inside to
outside.

A special procedure is applied if no test succeeds but the remaining command line
string contains no null character (implying the remaining word is the one for which
completions are to be generated). The completion target is restricted to the remain‐
ing word and any actions for the corresponding patterns are executed. In this case,
nothing is stripped from the command line string. The order of evaluation of the ac‐
tions can be determined by the tag-order style; the various formats supported by _al‐‐
ternative can be used in action. The descr is used for setting up the array parameter
expl.

Specification arguments take one of following forms, in which metacharacters such as
`(', `)', `#' and `|' should be quoted.

/pattern/ [%lookahead%] [-guard] [:tag:descr:action]
This is a single primitive component. The function tests whether the combined
pattern `(#b)((#B)pattern)lookahead*' matches the command line string. If so,
`guard' is evaluated and its return status is examined to determine if the test
has succeeded. The pattern string `[]' is guaranteed never to match. The
lookahead is not stripped from the command line before the next pattern is ex‐
amined.

The argument starting with : is used in the same manner as an argument to _al‐‐
ternative.

A component is used as follows: pattern is tested to see if the component al‐
ready exists on the command line. If it does, any following specifications are
examined to find something to complete. If a component is reached but no such
pattern exists yet on the command line, the string containing the action is
used to generate matches to insert at that point.

/pattern/+ [%lookahead%] [-guard] [:tag:descr:action]
This is similar to `/pattern/ ...' but the left part of the command line string
(i.e. the part already matched by previous patterns) is also considered part of
the completion target.

/pattern/- [%lookahead%] [-guard] [:tag:descr:action]
This is similar to `/pattern/ ...' but the actions of the current and previ‐
ously matched patterns are ignored even if the following `pattern' matches the
empty string.

( spec )
Parentheses may be used to groups specs; note each parenthesis is a single ar‐
gument to _regex_arguments.

spec # This allows any number of repetitions of spec.

spec spec
The two specs are to be matched one after the other as described above.

spec | spec
Either of the two specs can be matched.

The function _regex_words can be used as a helper function to generate matches for a
set of alternative words possibly with their own arguments as a command line argument.

Examples:

_regex_arguments _tst /$'[^\0]#\0'/ \
/$'[^\0]#\0'/ :'compadd aaa'

This generates a function _tst that completes aaa as its only argument. The tag and
description for the action have been omitted for brevity (this works but is not recom‐
mended in normal use). The first component matches the command word, which is arbi‐
trary; the second matches any argument. As the argument is also arbitrary, any fol‐
lowing component would not depend on aaa being present.

_regex_arguments _tst /$'[^\0]#\0'/ \
/$'aaa\0'/ :'compadd aaa'

This is a more typical use; it is similar, but any following patterns would only match
if aaa was present as the first argument.

_regex_arguments _tst /$'[^\0]#\0'/ $ \
/$'aaa\0'/ :'compadd aaa' \
/$'bbb\0'/ :'compadd bbb' $ \#

In this example, an indefinite number of command arguments may be completed. Odd ar‐
guments are completed as aaa and even arguments as bbb. Completion fails unless the
set of aaa and bbb arguments before the current one is matched correctly.

_regex_arguments _tst /$'[^\0]#\0'/ \
$ /$'aaa\0'/ :'compadd aaa' \| \
/$'bbb\0'/ :'compadd bbb' $ \#

This is similar, but either aaa or bbb may be completed for any argument. In this
case _regex_words could be used to generate a suitable expression for the arguments.

_regex_words tag description spec ...
This function can be used to generate arguments for the _regex_arguments command which
may be inserted at any point where a set of rules is expected. The tag and descrip‐
tion give a standard tag and description pertaining to the current context. Each spec
contains two or three arguments separated by a colon: note that there is no leading
colon in this case.

Each spec gives one of a set of words that may be completed at this point, together
with arguments. It is thus roughly equivalent to the _arguments function when used in
normal (non-regex) completion.

The part of the spec before the first colon is the word to be completed. This may
contain a *; the entire word, before and after the * is completed, but only the text
before the * is required for the context to be matched, so that further arguments may
be completed after the abbreviated form.

The second part of spec is a description for the word being completed.

The optional third part of the spec describes how words following the one being com‐
pleted are themselves to be completed. It will be evaluated in order to avoid prob‐
lems with quoting. This means that typically it contains a reference to an array con‐
taining previously generated regex arguments.

The option -t term specifies a terminator for the word instead of the usual space.
This is handled as an auto-removable suffix in the manner of the option -s sep to
_values.

The result of the processing by _regex_words is placed in the array reply, which
should be made local to the calling function. If the set of words and arguments may
be matched repeatedly, a # should be appended to the generated array at that point.

For example:

local -a reply
_regex_words mydb-commands 'mydb commands' \
'add:add an entry to mydb:$mydb_add_cmds' \
'show:show entries in mydb'
_regex_arguments _mydb "$reply[@]"
_mydb "$@"

This shows a completion function for a command mydb which takes two command arguments,
add and show. show takes no arguments, while the arguments for add have already been
prepared in an array mydb_add_cmds, quite possibly by a previous call to _regex_words.

_requested [ -x ] [ -12VJ ] tag [ name descr [ command [ arg ... ] ]
This function is called to decide whether a tag already registered by a call to _tags
(see below) has been requested by the user and hence completion should be performed
for it. It returns status zero if the tag is requested and non-zero otherwise. The
function is typically used as part of a loop over different tags as follows:

_tags foo bar baz
while _tags; do
if _requested foo; then
... # perform completion for foo
fi
... # test the tags bar and baz in the same way
... # exit loop if matches were generated
done

Note that the test for whether matches were generated is not performed until the end
of the _tags loop. This is so that the user can set the tag-order style to specify a
set of tags to be completed at the same time.

If name and descr are given, _requested calls the _description function with these ar‐
guments together with the options passed to _requested.

If command is given, the _all_labels function will be called immediately with the same
arguments. In simple cases this makes it possible to perform the test for the tag and
the matching in one go. For example:

local expl ret=1
_tags foo bar baz
while _tags; do
_requested foo expl 'description' \
compadd foobar foobaz && ret=0
...
(( ret )) || break
done

If the command is not compadd, it must nevertheless be prepared to handle the same op‐
tions.

_retrieve_cache cache_identifier
This function retrieves completion information from the file given by cache_identi‐
fier, stored in a directory specified by the cache-path style which defaults to
~/.zcompcache. The return status is zero if retrieval was successful. It will only
attempt retrieval if the use-cache style is set, so you can call this function without
worrying about whether the user wanted to use the caching layer.

See _store_cache below for more details.

_sep_parts
This function is passed alternating arrays and separators as arguments. The arrays
specify completions for parts of strings to be separated by the separators. The ar‐
rays may be the names of array parameters or a quoted list of words in parentheses.
For example, with the array `hosts=(ftp news)' the call `_sep_parts '(foo bar)' @
hosts' will complete the string `f' to `foo' and the string `b@n' to `bar@news'.

This function accepts the compadd options `-V', `-J', `-1', `-2', `-n', `-X', `-M',
`-P', `-S', `-r', `-R', and `-q' and passes them on to the compadd builtin used to add
the matches.

_sequence [ -s sep ] [ -n max ] [ -d ] function [ - ] ...
This function is a wrapper to other functions for completing items in a separated
list. The same function is used to complete each item in the list. The separator is
specified with the -s option. If -s is omitted it will use `,'. Duplicate values are
not matched unless -d is specified. If there is a fixed or maximum number of items in
the list, this can be specified with the -n option.

Common compadd options are passed on to the function. It is possible to use compadd
directly with _sequence, though _values may be more appropriate in this situation.

_setup tag [ group ]
This function sets up the special parameters used by the completion system appropri‐
ately for the tag given as the first argument. It uses the styles list-colors,
list-packed, list-rows-first, last-prompt, accept-exact, menu and force-list.

The optional group supplies the name of the group in which the matches will be placed.
If it is not given, the tag is used as the group name.

This function is called automatically from _description and hence is not normally
called explicitly.

_store_cache cache_identifier param ...
This function, together with _retrieve_cache and _cache_invalid, implements a caching
layer which can be used in any completion function. Data obtained by costly opera‐
tions are stored in parameters; this function then dumps the values of those parame‐
ters to a file. The data can then be retrieved quickly from that file via _re‐‐
trieve_cache, even in different instances of the shell.

The cache_identifier specifies the file which the data should be dumped to. The file
is stored in a directory specified by the cache-path style which defaults to ~/.zcomp‐‐
cache. The remaining params arguments are the parameters to dump to the file.

The return status is zero if storage was successful. The function will only attempt
storage if the use-cache style is set, so you can call this function without worrying
about whether the user wanted to use the caching layer.

The completion function may avoid calling _retrieve_cache when it already has the com‐
pletion data available as parameters. However, in that case it should call _cache_in‐‐
valid to check whether the data in the parameters and in the cache are still valid.

See the _perl_modules completion function for a simple example of the usage of the
caching layer.

_tags [ [ -C name ] tag ... ]
If called with arguments, these are taken to be the names of tags valid for comple‐
tions in the current context. These tags are stored internally and sorted by using
the tag-order style.

Next, _tags is called repeatedly without arguments from the same completion function.
This successively selects the first, second, etc. set of tags requested by the user.
The return status is zero if at least one of the tags is requested and non-zero other‐
wise. To test if a particular tag is to be tried, the _requested function should be
called (see above).

If `-C name' is given, name is temporarily stored in the argument field (the fifth) of
the context in the curcontext parameter during the call to _tags; the field is re‐
stored on exit. This allows _tags to use a more specific context without having to
change and reset the curcontext parameter (which has the same effect).

_tilde_files
Like _files, but resolve leading tildes according to the rules of filename expansion,
so the suggested completions don't start with a `~' even if the filename on the com‐
mand-line does.

_values [ -O name ] [ -s sep ] [ -S sep ] [ -wC ] desc spec ...
This is used to complete arbitrary keywords (values) and their arguments, or lists of
such combinations.

If the first argument is the option `-O name', it will be used in the same way as by
the _arguments function. In other words, the elements of the name array will be
passed to compadd when executing an action.

If the first argument (or the first argument after `-O name') is `-s', the next argu‐
ment is used as the character that separates multiple values. This character is auto‐
matically added after each value in an auto-removable fashion (see below); all values
completed by `_values -s' appear in the same word on the command line, unlike comple‐
tion using _arguments. If this option is not present, only a single value will be
completed per word.

Normally, _values will only use the current word to determine which values are already
present on the command line and hence are not to be completed again. If the -w option
is given, other arguments are examined as well.

The first non-option argument, desc, is used as a string to print as a description be‐
fore listing the values.

All other arguments describe the possible values and their arguments in the same for‐
mat used for the description of options by the _arguments function (see above). The
only differences are that no minus or plus sign is required at the beginning, values
can have only one argument, and the forms of action beginning with an equal sign are
not supported.

The character separating a value from its argument can be set using the option -S
(like -s, followed by the character to use as the separator in the next argument). By
default the equals sign will be used as the separator between values and arguments.

Example:

_values -s , 'description' \
'*foo[bar]' \
'(two)*one[number]:first count:' \
'two[another number]::second count:(1 2 3)'

This describes three possible values: `foo', `one', and `two'. The first is described
as `bar', takes no argument and may appear more than once. The second is described as
`number', may appear more than once, and takes one mandatory argument described as
`first count'; no action is specified, so it will not be completed. The `(two)' at
the beginning says that if the value `one' is on the line, the value `two' will no
longer be considered a possible completion. Finally, the last value (`two') is de‐
scribed as `another number' and takes an optional argument described as `second count'
for which the completions (to appear after an `=') are `1', `2', and `3'. The _values
function will complete lists of these values separated by commas.

Like _arguments, this function temporarily adds another context name component to the
arguments element (the fifth) of the current context while executing the action. Here
this name is just the name of the value for which the argument is completed.

The style verbose is used to decide if the descriptions for the values (but not those
for the arguments) should be printed.

The associative array val_args is used to report values and their arguments; this
works similarly to the opt_args associative array used by _arguments. Hence the func‐
tion calling _values should declare the local parameters state, state_descr, line,
context and val_args:

local context state state_descr line
typeset -A val_args

when using an action of the form `->string'. With this function the context parameter
will be set to the name of the value whose argument is to be completed. Note that for
_values, the state and state_descr are scalars rather than arrays. Only a single
matching state is returned.

Note also that _values normally adds the character used as the separator between val‐
ues as an auto-removable suffix (similar to a `/' after a directory). However, this
is not possible for a `->string' action as the matches for the argument are generated
by the calling function. To get the usual behaviour, the calling function can add the
separator x as a suffix by passing the options `-qS x' either directly or indirectly
to compadd.

The option -C is treated in the same way as it is by _arguments. In that case the pa‐
rameter curcontext should be made local instead of context (as described above).

_wanted [ -x ] [ -C name ] [ -12VJ ] tag name descr command [ arg ...]
In many contexts, completion can only generate one particular set of matches, usually
corresponding to a single tag. However, it is still necessary to decide whether the
user requires matches of this type. This function is useful in such a case.

The arguments to _wanted are the same as those to _requested, i.e. arguments to be
passed to _description. However, in this case the command is not optional; all the
processing of tags, including the loop over both tags and tag labels and the genera‐
tion of matches, is carried out automatically by _wanted.

Hence to offer only one tag and immediately add the corresponding matches with the
given description:

local expl
_wanted tag expl 'description' \
compadd matches...

Note that, as for _requested, the command must be able to accept options to be passed
down to compadd.

Like _tags this function supports the -C option to give a different name for the argu‐
ment context field. The -x option has the same meaning as for _description.

_widgets [ -g pattern ]
This function completes names of zle widgets (see the section `Widgets' in zshzle(1)).
The pattern, if present, is matched against values of the $widgets special parameter,
documented in the section `The zsh/zleparameter Module' in zshmodules(1).

COMPLETION SYSTEM VARIABLES
There are some standard variables, initialised by the _main_complete function and then used
from other functions.

The standard variables are:

_comp_caller_options
The completion system uses setopt to set a number of options. This allows functions to
be written without concern for compatibility with every possible combination of user
options. However, sometimes completion needs to know what the user's option prefer‐
ences are. These are saved in the _comp_caller_options associative array. Option
names, spelled in lowercase without underscores, are mapped to one or other of the
strings `on' and `off'.

_comp_priv_prefix
Completion functions such as _sudo can set the _comp_priv_prefix array to a
command prefix that may then be used by _call_program to match the privileges
when calling programs to generate matches.

Two more features are offered by the _main_complete function. The arrays compprefuncs
and comppostfuncs may contain names of functions that are to be called immediately be‐
fore or after completion has been tried. A function will only be called once unless
it explicitly reinserts itself into the array.

COMPLETION DIRECTORIES
In the source distribution, the files are contained in various subdirectories of the Comple‐‐
tion directory. They may have been installed in the same structure, or into one single func‐
tion directory. The following is a description of the files found in the original directory
structure. If you wish to alter an installed file, you will need to copy it to some direc‐
tory which appears earlier in your fpath than the standard directory where it appears.

Base The core functions and special completion widgets automatically bound to keys. You
will certainly need most of these, though will probably not need to alter them. Many
of these are documented above.

Zsh Functions for completing arguments of shell builtin commands and utility functions for
this. Some of these are also used by functions from the Unix directory.

Unix Functions for completing arguments of external commands and suites of commands. They
may need modifying for your system, although in many cases some attempt is made to de‐
cide which version of a command is present. For example, completion for the mount
command tries to determine the system it is running on, while completion for many
other utilities try to decide whether the GNU version of the command is in use, and
hence whether the --help option is supported.

X, AIX, BSD, ...
Completion and utility function for commands available only on some systems. These
are not arranged hierarchically, so, for example, both the Linux and Debian directo‐
ries, as well as the X directory, may be useful on your system.

zsh 5.8.1 February 12, 2022 ZSHCOMPSYS(1)