<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
**Table of Contents**  *generated with [DocToc](https://github.com/thlorenz/doctoc)*

- [20 Completion System](#20-completion-system)
  - [20.1 Description](#201-description)
  - [20.2 Initialization](#202-initialization)
    - [20.2.1 Use of compinit](#2021-use-of-compinit)
    - [20.2.2 Autoloaded files](#2022-autoloaded-files)
    - [20.2.3 Functions](#2023-functions)
  - [20.3 Completion System Configuration](#203-completion-system-configuration)
    - [20.3.1 Overview](#2031-overview)
    - [20.3.2 Standard Tags](#2032-standard-tags)
    - [20.3.3 Standard Styles](#2033-standard-styles)
  - [20.4 Control Functions](#204-control-functions)
  - [20.5 Bindable Commands](#205-bindable-commands)
  - [20.6 Utility Functions](#206-utility-functions)
  - [20.7 Completion System Variables](#207-completion-system-variables)
  - [20.8 Completion Directories](#208-completion-directories)

<!-- END doctoc generated TOC please keep comment here to allow auto update -->

<span id="Completion-System"></span> <span
id="Completion-System-1"></span>

# 20 Completion System

<span id="index-completion-system"></span> <span
id="index-completion_002c-programmable-1"></span> <span
id="index-completion_002c-controlling-1"></span>

------------------------------------------------------------------------

<span id="Description-2"></span>

## 20.1 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 the previous chapter, [Completion
Widgets](Completion-Widgets.html#Completion-Widgets).

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 in
[Initialization](#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 indicating a class of object that the user may need
to distinguish. For example, when completing 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 [The zsh/zutil
Module](Zsh-Modules.html#The-zsh_002fzutil-Module).

In summary, tags describe *what* the completion objects are, and style
how they are to be completed. 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
description of context handling, which determines how tags and other
elements of the context influence the behaviour of styles, is described
in [Completion System Configuration](#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 completion, 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.

------------------------------------------------------------------------

<span id="Initialization"></span> <span id="Initialization-1"></span>

## 20.2 Initialization

<span id="index-compinstall"></span> <span
id="index-completion-system_002c-installing"></span>

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 compinstall can be run by a user to
configure various aspects of the completion system.

Usually, compinstall will insert code into .zshrc, although if 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 autoloaded
(‘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.

------------------------------------------------------------------------

<span id="Use-of-compinit"></span>

### 20.2.1 Use of compinit

<span id="index-compinit"></span> <span
id="index-completion-system_002c-initializing"></span>

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 necessary shell
functions to be autoloaded, and will then re-define all widgets that do
completion to use the new system. If you use the menu-select widget,
which is part of the zsh/complist 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 expansion.

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 #compdef 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 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, provided the dumpfile exists.

<span id="index-compaudit"></span>

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 directories, adding missing ones to fpath as
necessary. To force a check of exactly the directories currently named
in fpath, set \_compdir to an empty string before calling compaudit or
compinit.

<span id="index-bashcompinit"></span>

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.

------------------------------------------------------------------------

<span id="Autoloaded-files"></span>

### 20.2.2 Autoloaded files

<span id="index-completion-system_002c-autoloaded-functions"></span>

The convention for autoloaded functions used in completion is that they
start with an underscore; 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 automatically
contains the required directories for the standard functions.

For incomplete installations, if compinit does not find enough files
beginning with an underscore (fewer than twenty) in the search path, it
will try to find more by adding the directory \_compdir to the search
path. If that directory has a subdirectory named Base, all
subdirectories will be added to the path. Furthermore, if the
subdirectory Base has a subdirectory 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.

<span id="index-compdef_002c-use-of-by-compinit"></span>

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 `name`s, 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-sequence`s, if any. The `style` must be
one of the builtin widgets that perform completion, namely
complete-word, delete-char-or-list, expand-or-complete,
expand-or-complete-prefix, list-choices, menu-complete,
menu-expand-or-complete, or reverse-menu-complete. If the zsh/complist
module is loaded (see [The zsh/complist
Module](Zsh-Modules.html#The-zsh_002fcomplist-Module)) the widget
menu-select is also available.

When one of the `key-sequence`s 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 `widget-name` should
not clash with the name of any existing widget: names based on the name
of the function are most useful. For example,

<div class="example">

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

</div>

(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:

<span
id="index-_002darray_002dvalue_002d_002c-completion-context"></span>

-array-value-

The right hand side of an array-assignment (‘`name`=(`...`)’)

<span
id="index-_002dassign_002dparameter_002d_002c-completion-context"></span>

-assign-parameter-

The name of a parameter in an assignment, i.e. on the left hand side of
an ‘=’

<span
id="index-_002dbrace_002dparameter_002d_002c-completion-context"></span>

-brace-parameter-

The name of a parameter expansion within braces (‘${`...`}’)

<span id="index-_002dcommand_002d_002c-completion-context"></span>

-command-

A word in command position

<span id="index-_002dcondition_002d_002c-completion-context"></span>

-condition-

A word inside a condition (‘\[\[`...`\]\]’)

<span id="index-_002ddefault_002d_002c-completion-context"></span>

-default-

Any word for which no other completion is defined

<span id="index-_002dequal_002d_002c-completion-context"></span>

-equal-

A word beginning with an equals sign

<span id="index-_002dfirst_002d_002c-completion-context"></span>

-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.

<span id="index-_002dmath_002d_002c-completion-context"></span>

-math-

Inside mathematical contexts, such as ‘((`...`))’

<span id="index-_002dparameter_002d_002c-completion-context"></span>

-parameter-

The name of a parameter expansion (‘$`...`’)

<span id="index-_002dredirect_002d_002c-completion-context"></span>

-redirect-

The word after a redirection operator.

<span id="index-_002dsubscript_002d_002c-completion-context"></span>

-subscript-

The contents of a parameter subscript.

<span id="index-_002dtilde_002d_002c-completion-context"></span>

-tilde-

After an initial tilde (‘\~’), but before the first slash in the word.

<span id="index-_002dvalue_002d_002c-completion-context"></span>

-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 example, 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:

<div class="example">

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

</div>

completes files matching ‘\*.log’ after ‘2> \<TAB>’ for any command with
no more specific handler defined.

Also:

<div class="example">

```zsh
compdef _foo -value-,-default-,-default-
```

</div>

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

<div class="example">

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

</div>

is another way to make completion after ‘2> \<TAB>’ complete files
matching ‘\*.log’.

------------------------------------------------------------------------

<span id="Functions-3"></span>

### 20.2.3 Functions

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

<span id="index-compdef"></span> <span
id="index-completion-system_002c-adding-definitions"></span>

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
completion function. For example, to complete files ending in ‘.h’ as
arguments to the command foo:

<div class="example">

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

</div>

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 `name`s 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 patterns 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 function 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-sequence`s; this is like the
#compdef -k tag. The function should generate the completions needed and
will otherwise behave like the builtin widget whose name is given as the
`style` argument. The widgets usable for this are: complete-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-seq`uence, 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 autoload -U `function`.

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

<div class="example">

```zsh
compdef _pids foo
```

</div>

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.

------------------------------------------------------------------------

<span id="Completion-System-Configuration"></span> <span
id="Completion-System-Configuration-1"></span>

## 20.3 Completion System Configuration

<span id="index-completion-system_002c-configuration"></span>

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.

------------------------------------------------------------------------

<span id="Overview-2"></span>

### 20.3.1 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 meaning 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 option as an argument).

The context starts out very generic ("we are beginning a completion")
and becomes more specific 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
example 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 ([The zsh/zutil
Module](Zsh-Modules.html#The-zsh_002fzutil-Module)).

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 surrounding colons appear anyway.
The fields are always in the order
:completion:`function`:`completer`:`command`:`argument`:`tag`. These
have the following meaning:

-   The literal string completion, saying that this style is used by the
    completion system. 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 normal 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 underscore 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
    behaviour of a later completer. See [Control
    Functions](#Control-Functions) for more information.
-   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 usually 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 function 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`
options. Finally, the `tag` is added when the types of completion are
known. For example, the context name

<div class="example">

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

</div>

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

<div class="example">

```zsh
dvips -o ...
```

</div>

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 restricted 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 [Bindable Commands](#Bindable-Commands).

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) pattern, and the name of the style itself, which must be
matched exactly. The following examples demonstrate that 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

<div class="example">

```zsh
zstyle ':completion:*' verbose yes
```

</div>

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
pattern 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:

<div class="example">

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

</div>

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

<div class="example">

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

</div>

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 [Completion
Widgets](Completion-Widgets.html#Completion-Widgets))). For example,

<div class="example">

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

</div>

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 another 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. Strings are preferred over
patterns (for example, ‘:completion::complete:::foo’ is more specific
than ‘:completion::complete:::\*’), and longer patterns are preferred
over the pattern ‘\*’. See [The zsh/zutil
Module](Zsh-Modules.html#The-zsh_002fzutil-Module) for details.

Context patterns that use something other than a wildcard (\*) to match
the middle parts of the context — the `completer`, `command`, and
`argument` in
:completion:`function`:`completer`:`command`:`argument`:`tag` — should
include all six colons (:) explicitly. Without this, a pattern such as
:completion:\*:foo:\* could match foo against a component other than the
intended one (for example, against `completer` when a match against
`command` was intended).

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.

------------------------------------------------------------------------

<span id="Standard-Tags"></span>

### 20.3.2 Standard Tags

<span id="index-completion-system_002c-tags"></span>

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

<span id="index-accounts_002c-completion-tag"></span>

accounts

used to look up the users-hosts style

<span id="index-all_002dexpansions_002c-completion-tag"></span>

all-expansions

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

<span id="index-all_002dfiles_002c-completion-tag"></span>

all-files

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

<span id="index-arguments_002c-completion-tag"></span>

arguments

for arguments to a command

<span id="index-arrays_002c-completion-tag"></span>

arrays

for names of array parameters

<span id="index-association_002dkeys_002c-completion-tag"></span>

association-keys

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

<span id="index-bookmarks_002c-completion-tag"></span>

bookmarks

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

<span id="index-builtins_002c-completion-tag"></span>

builtins

for names of builtin commands

<span id="index-characters_002c-completion-tag"></span>

characters

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

<span id="index-colormapids_002c-completion-tag"></span>

colormapids

for X colormap ids

<span id="index-colors_002c-completion-tag"></span>

colors

for color names

<span id="index-commands_002c-completion-tag"></span>

commands

for names of external commands. Also used by complex commands such as
cvs when completing names subcommands.

<span id="index-contexts_002c-completion-tag"></span>

contexts

for contexts in arguments to the zstyle builtin command

<span id="index-corrections_002c-completion-tag"></span>

corrections

used by the \_approximate and \_correct completers for possible
corrections

<span id="index-cursors_002c-completion-tag"></span>

cursors

for cursor names used by X programs

<span id="index-default_002c-completion-tag"></span>

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 context name is set

<span id="index-descriptions_002c-completion-tag"></span>

descriptions

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

<span id="index-devices_002c-completion-tag"></span>

devices

for names of device special files

<span id="index-directories_002c-completion-tag"></span>

directories

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

<span id="index-directory_002dstack_002c-completion-tag"></span>

directory-stack

for entries in the directory stack

<span id="index-displays_002c-completion-tag"></span>

displays

for X display names

<span id="index-domains_002c-completion-tag"></span>

domains

for network domains

<span id="index-email_002d_002a_002c-completion-tag"></span>

email-`plugin`

for email addresses from the ‘\_email-`plugin`’ backend of
\_email_addresses

<span id="index-expansions_002c-completion-tag"></span>

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

<span id="index-extensions_002c-completion-tag"></span>

extensions

for X server extensions

<span id="index-file_002ddescriptors_002c-completion-tag"></span>

file-descriptors

for numbers of open file descriptors

<span id="index-files_002c-completion-tag"></span>

files

the generic file-matching tag used by functions completing filenames

<span id="index-fonts_002c-completion-tag"></span>

fonts

for X font names

<span id="index-fstypes_002c-completion-tag"></span>

fstypes

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

<span id="index-functions_002c-completion-tag"></span>

functions

names of functions — normally shell functions, although certain commands
may understand other kinds of function

<span id="index-globbed_002dfiles_002c-completion-tag"></span>

globbed-files

for filenames when the name has been generated by pattern matching

<span id="index-groups_002c-completion-tag"></span>

groups

for names of user groups

<span id="index-history_002dwords_002c-completion-tag"></span>

history-words

for words from the history

<span id="index-hosts_002c-completion-tag"></span>

hosts

for hostnames

<span id="index-indexes_002c-completion-tag"></span>

indexes

for array indexes

<span id="index-interfaces_002c-completion-tag"></span>

interfaces

for network interfaces

<span id="index-jobs_002c-completion-tag"></span>

jobs

for jobs (as listed by the ‘jobs’ builtin)

<span id="index-keymaps_002c-completion-tag"></span>

keymaps

for names of zsh keymaps

<span id="index-keysyms_002c-completion-tag"></span>

keysyms

for names of X keysyms

<span id="index-libraries_002c-completion-tag"></span>

libraries

for names of system libraries

<span id="index-limits_002c-completion-tag"></span>

limits

for system limits

<span id="index-local_002ddirectories_002c-completion-tag"></span>

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

<span id="index-mailboxes_002c-completion-tag"></span>

mailboxes

for e-mail folders

<span id="index-manuals_002c-completion-tag"></span>

manuals

for names of manual pages

<span id="index-maps_002c-completion-tag"></span>

maps

for map names (e.g. NIS maps)

<span id="index-messages_002c-completion-tag"></span>

messages

used to look up the format style for messages

<span id="index-modifiers_002c-completion-tag"></span>

modifiers

for names of X modifiers

<span id="index-modules_002c-completion-tag"></span>

modules

for modules (e.g. zsh modules)

<span id="index-my_002daccounts_002c-completion-tag"></span>

my-accounts

used to look up the users-hosts style

<span id="index-named_002ddirectories_002c-completion-tag"></span>

named-directories

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

<span id="index-names_002c-completion-tag"></span>

names

for all kinds of names

<span id="index-newsgroups_002c-completion-tag"></span>

newsgroups

for USENET groups

<span id="index-nicknames_002c-completion-tag"></span>

nicknames

for nicknames of NIS maps

<span id="index-options_002c-completion-tag"></span>

options

for command options

<span id="index-original_002c-completion-tag"></span>

original

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

<span id="index-other_002daccounts_002c-completion-tag"></span>

other-accounts

used to look up the users-hosts style

<span id="index-packages_002c-completion-tag"></span>

packages

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

<span id="index-parameters_002c-completion-tag"></span>

parameters

for names of parameters

<span id="index-path_002ddirectories_002c-completion-tag"></span>

path-directories

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

<span id="index-paths_002c-completion-tag"></span>

paths

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

<span id="index-pods_002c-completion-tag"></span>

pods

for perl pods (documentation files)

<span id="index-ports_002c-completion-tag"></span>

ports

for communication ports

<span id="index-prefixes_002c-completion-tag"></span>

prefixes

for prefixes (like those of a URL)

<span id="index-printers_002c-completion-tag"></span>

printers

for print queue names

<span id="index-processes_002c-completion-tag"></span>

processes

for process identifiers

<span id="index-processes_002dnames_002c-completion-tag"></span>

processes-names

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

<span id="index-sequences_002c-completion-tag"></span>

sequences

for sequences (e.g. mh sequences)

<span id="index-sessions_002c-completion-tag"></span>

sessions

for sessions in the zftp function suite

<span id="index-signals_002c-completion-tag"></span>

signals

for signal names

<span id="index-strings_002c-completion-tag"></span>

strings

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

<span id="index-styles_002c-completion-tag"></span>

styles

for styles used by the zstyle builtin command

<span id="index-suffixes_002c-completion-tag"></span>

suffixes

for filename extensions

<span id="index-tags_002c-completion-tag"></span>

tags

for tags (e.g. rpm tags)

<span id="index-targets_002c-completion-tag"></span>

targets

for makefile targets

<span id="index-time_002dzones_002c-completion-tag"></span>

time-zones

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

<span id="index-types_002c-completion-tag"></span>

types

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

<span id="index-urls_002c-completion-tag"></span>

urls

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

<span id="index-users_002c-completion-tag"></span>

users

for usernames

<span id="index-values_002c-completion-tag"></span>

values

for one of a set of values in certain lists

<span id="index-variant_002c-completion-tag"></span>

variant

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

<span id="index-visuals_002c-completion-tag"></span>

visuals

for X visuals

<span id="index-warnings_002c-completion-tag"></span>

warnings

used to look up the format style for warnings

<span id="index-widgets_002c-completion-tag"></span>

widgets

for zsh widget names

<span id="index-windows_002c-completion-tag"></span>

windows

for IDs of X windows

<span id="index-zsh_002doptions_002c-completion-tag"></span>

zsh-options

for shell options

------------------------------------------------------------------------

<span id="Standard-Styles"></span>

### 20.3.3 Standard Styles

<span id="index-completion-system_002c-styles"></span>

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
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:

<div class="example">

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

</div>

<span id="index-accept_002dexact_002c-completion-style"></span>

accept-exact

This is tested for the default tag in addition to the tags valid for the
current context. 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 otherwise be considered ambiguous).

When completing pathnames (where the tag used is ‘paths’) this style
accepts any number 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 directory
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.

<span id="index-accept_002dexact_002ddirs_002c-completion-style"></span>

accept-exact-dirs

This is used by filename completion. Unlike accept-exact it is a
boolean. By default, filename completion examines all components of a
path to see if there are completions 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 below) to ‘false’.

<span id="index-add_002dspace_002c-completion-style"></span>

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.

<span id="index-ambiguous_002c-completion-style"></span>

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 ambiguous component, even if menu completion is in
use. The style is always tested with the paths tag.

<span id="index-assign_002dlist_002c-completion-style"></span>

assign-list

When completing after an equals sign that is being treated as an
assignment, the completion 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.

<span id="index-auto_002ddescription_002c-completion-style"></span>

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 sequence ‘%d’ in the value will be replaced by
the description for this argument. Depending 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.

<span id="index-avoid_002dcompleter_002c-completion-style"></span>

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.

<span id="index-cache_002dpath_002c-completion-style"></span>

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.

<span id="index-cache_002dpolicy_002c-completion-style"></span>

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.

<span id="index-call_002dcommand_002c-completion-style"></span>

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’.

<span id="index-command_002c-completion-style"></span>

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 command 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 processes 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.

<span id="index-command_002dpath_002c-completion-style"></span>

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.

<span id="index-commands_002c-completion-style"></span>

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’.

<span id="index-complete_002c-completion-style"></span>

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.

<span id="index-complete_002doptions_002c-completion-style"></span>

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 after an
initial - unless there is a preceding -- on the command line.

<span id="index-completer_002c-completion-style"></span>

completer

The strings given as the value of this style provide the names of the
completer functions to use. The available completer functions are
described in [Control Functions](#Control-Functions).

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 underscores replaced by hyphens.
In the second case the `function` is the name of the completer 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:

<div class="example">

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

</div>

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 completer;
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.

<span id="index-condition_002c-completion-style"></span>

condition

This style is used by the \_list completer function to decide if
insertion of matches should be delayed unconditionally. The default is
‘true’.

<span id="index-delimiters_002c-completion-style"></span>

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 become confused. The
default list is :, +, /, -, %. The list may be empty to force a
delimiter to be typed.

<span id="index-disabled_002c-completion-style"></span>

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’.

<span id="index-domains_002c-completion-style"></span>

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.

<span id="index-environ_002c-completion-style"></span>

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 completion for the target command is invoked.

<div class="example">

```zsh
zstyle ':completion:*:sudo::' environ \ 
  PATH="/sbin:/usr/sbin:$PATH" HOME="/root"
```

</div>

<span id="index-expand_002c-completion-style"></span>

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.

<span id="index-extra_002dverbose_002c-completion-style"></span>

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’.

<span id="index-fake_002c-completion-style"></span>

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`:`description`’; 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 features when completing files or
parameters.

<span id="index-fake_002dalways_002c-completion-style"></span>

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 setting 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 contains a fixed set of directories. This has the
effect of adding the match group ‘extra directories’ with the given
completions.

<div class="example">

```zsh
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 '*'
```

</div>

<span id="index-fake_002dfiles_002c-completion-style"></span>

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 pathnames 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.

<span id="index-fake_002dparameters_002c-completion-style"></span>

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.

<span id="index-file_002dlist_002c-completion-style"></span>

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 this the following code can be included in an
initialization file:

<div class="example">

```zsh
zmodload -i zsh/stat
disable stat
```

</div>

The style may either be set to a ‘true’ value (or ‘all’), or one of the
values ‘insert’ or ‘list’, indicating that files are to be listed in
long format in all circumstances, 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 followed by =`num`. If `num` is present it gives the maximum
number of matches for which long listing style will be used. For
example,

<div class="example">

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

</div>

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.

<div class="example">

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

</div>

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

<span id="index-file_002dpatterns_002c-completion-style"></span>

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 `tag`s of all strings in the value will be offered by \_files and
used when looking up other styles. Any `tag`s in the same word will be
offered at the same time and before 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. The inclusion of a description also gives
precedence to associated options such as for completion grouping so it
can be used where files should be separated.

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:

<div class="example">

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

</div>

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:

<div class="example">

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

</div>

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.

To separate directories into a separate group from the files but still
complete them at the first attempt, a description needs to be given.
Note that directories need to be explicitly excluded from the
globbed-files because ‘\*’ will match directories. For grouping, it is
also necessary to set the group-name style.

<div class="example">

```zsh
zstyle ':completion:*' file-patterns \ 
    '%p(^-/):globbed-files *(-/):directories:location'
```

</div>

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

<span id="index-file_002dsort_002c-completion-style"></span>

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.

<span id="index-file_002dsplit_002dchars_002c-completion-style"></span>

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 ignored when completing
files. As this is quite heavy-handed, it is usually preferable to update
completion functions for contexts where this behaviour is useful.

<span id="index-filter_002c-completion-style"></span>

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
connect to your LDAP server.

<span id="index-force_002dlist_002c-completion-style"></span>

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.

<span id="index-format_002c-completion-style"></span>

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 [Completion
Widgets](Completion-Widgets.html#Completion-Widgets)).

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 [The zsh/zutil
Module](Zsh-Modules.html#The-zsh_002fzutil-Module).

<span id="index-gain_002dprivileges_002c-completion-style"></span>

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 command 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.

<span id="index-glob_002c-completion-style"></span>

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 substitute style) or else the original
string from the line.

<span id="index-global_002c-completion-style"></span>

global

If this is set to ‘true’ (the default), the \_expand_alias completer and
bindable command will try to expand global aliases.

<span id="index-group_002dname_002c-completion-style"></span>

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 external commands, names of
aliases, shell functions and parameters and reserved words as possible
completions. To have the external commands and shell functions listed
separately:

<div class="example">

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

</div>

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 separately, one can just set:

<div class="example">

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

</div>

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

To display the group name in the output, see the format style (q.v.)
under the descriptions tag.

<span id="index-group_002dorder_002c-completion-style"></span>

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 completions 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:

<div class="example">

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

</div>

<span id="index-groups_002c-completion-style"></span>

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’.

<span id="index-hidden_002c-completion-style"></span>

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.

<span id="index-hosts_002c-completion-style"></span>

hosts

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

<span id="index-hosts_002dports_002c-completion-style"></span>

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.

<span id="index-ignore_002dline_002c-completion-style"></span>

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 completions. 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-exact 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 general 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.

<span id="index-ignore_002dparents_002c-completion-style"></span>

ignore-parents

The style is tested without a tag by the function completing pathnames
in order to determine 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 example, 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.

<span id="index-ignored_002dpatterns_002c-completion-style"></span>

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 parameter $fignore.

Note that the EXTENDED_GLOB option is set during the execution of
completion functions, so the characters ‘#’, ‘\~’ and ‘^’ have special
meanings in the patterns.

<span id="index-insert_002c-completion-style"></span>

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.

<span id="index-insert_002dids_002c-completion-style"></span>

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.

<span id="index-insert_002dsections_002c-completion-style"></span>

insert-sections

This style is used with tags of the form ‘manuals.`X`’ when completing
names of manual pages. If set and the `X` in the tag name matches the
section number of the page being completed, the section number is
inserted along with the page name. For example, given

<div class="example">

```zsh
zstyle ':completion:*:manuals.*' insert-sections true
```

</div>

man ssh\_\<TAB> may be completed to man 5 ssh_config.

The value may also be set to one of ‘prepend’, or ‘suffix’. ‘prepend’
behaves the same as ‘true’ as in the above example, while ‘suffix’ would
complete man ssh\_\<TAB> as man ssh_config.5.

This is especially useful in conjunction with separate-sections, as it
ensures that the page requested of man corresponds to the one displayed
in the completion listing when there are multiple pages with the same
name (e.g., printf(1) and printf(3)).

The default for this style is ‘false’.

<span id="index-insert_002dtab_002c-completion-style"></span>

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 unprocessed 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
parameter 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’.

<span id="index-insert_002dunambiguous_002c-completion-style"></span>

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 final completion. However, if this style
is ‘true’, the completer will start menu completion 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 already 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 ‘pattern’. Then the pattern on the line is left unchanged if it
does not match unambiguously.

<span id="index-keep_002dprefix_002c-completion-style"></span>

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 remaining completers may be called.

<span id="index-known_002dhosts_002dfiles"></span>

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.

<span id="index-last_002dprompt_002c-completion-style"></span>

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 completion, 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.

<span id="index-list_002c-completion-style"></span>

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’.

<span id="index-list_002dcolors_002c-completion-style"></span>

list-colors

If the zsh/complist module is loaded, this style can be used to set
color specifications. This mechanism replaces the use of the ZLS_COLORS
and ZLS_COLOURS parameters described in [The zsh/complist
Module](Zsh-Modules.html#The-zsh_002fcomplist-Module), but the syntax is
the same.

If this style is set for the default tag, the strings in the value are
taken as specifications that are to be used everywhere. If it is set for
other tags, the specifications 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:

<div class="example">

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

</div>

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

<span id="index-list_002ddirs_002dfirst_002c-completion-style"></span>

list-dirs-first

This is used by file completion and corresponds to a particular setting
of the file-patterns style. If set, the default directories to be
completed are listed separately from and before completion for other
files.

<span id="index-list_002dgrouped_002c-completion-style"></span>

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 commands 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.

<span id="index-list_002dpacked_002c-completion-style"></span>

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.

<span id="index-list_002dprompt_002c-completion-style"></span>

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 zsh/complist
Module](Zsh-Modules.html#The-zsh_002fcomplist-Module)). 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.

<span id="index-list_002drows_002dfirst_002c-completion-style"></span>

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.

<span id="index-list_002dseparator_002c-completion-style"></span>

list-separator

The value of this style is used in completion listing to separate the
string to complete from a description when possible (e.g. when
completing options). It defaults to ‘--’ (two hyphens).

<span id="index-list_002dsuffixes_002c-completion-style"></span>

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 components, all ambiguous components will be
shown. Otherwise, completion stops at the first ambiguous component.

<span id="index-local_002c-completion-style"></span>

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 directory name used by a user
placing web pages within their home area.

For example:

<div class="example">

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

</div>

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.

<span id="index-mail_002ddirectory_002c-completion-style"></span>

mail-directory

If set, zsh will assume that mailbox files can be found in the directory
specified. It defaults to ‘\~/Mail’.

<span id="index-match_002doriginal_002c-completion-style"></span>

match-original

This is used by the \_match completer. If it is set to only, \_match
will try to generate 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.

<span id="index-matcher_002c-completion-style"></span>

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 override them via the use of an x:
specification. The value should be in the form described in [Completion
Matching Control](Completion-Widgets.html#Completion-Matching-Control).
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 description of the tag-order style.

<span id="index-matcher_002dlist_002c-completion-style"></span>

matcher-list

This style can be set to a list of match specifications that are to be
applied everywhere. Match specifications are described in [Completion
Matching Control](Completion-Widgets.html#Completion-Matching-Control).
The completion system will try them one after another for each completer
selected. For example, to try first simple completion and, if that
generates no matches, case-insensitive completion:

<div class="example">

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

</div>

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:

<div class="example">

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

</div>

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 completion
only with \_complete:

<div class="example">

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

</div>

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 specifications 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:

<div class="example">

```zsh
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:|=*'
```

</div>

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 specifications 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, 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 effect, 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.

<span id="index-max_002derrors_002c-completion-style"></span>

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

<div class="example">

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

</div>

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 numeric’, 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’.

<span id="index-max_002dmatches_002dwidth_002c-completion-style"></span>

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 effect. 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 together; decreasing it will allow more of the
description to be visible.

<span id="index-menu_002c-completion-style"></span>

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 useful 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/complist module. The following values may appear either
alongside or instead of the values above.

If the value contains the string ‘select’, menu selection will be
started unconditionally.

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 number 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 ‘select=’ 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
zsh/complist Module](Zsh-Modules.html#The-zsh_002fcomplist-Module) 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’.

<span id="index-muttrc_002c-completion-style"></span>

muttrc

If set, gives the location of the mutt configuration file. It defaults
to ‘\~/.muttrc’.

<span id="index-numbers_002c-completion-style"></span>

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.

<span id="index-old_002dlist_002c-completion-style"></span>

old-list

This is used by the \_oldlist completer. If it is set to ‘always’, then
standard widgets 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 behaviour 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 generated 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.

<span id="index-old_002dmatches_002c-completion-style"></span>

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 unconditionally. 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.

<span id="index-old_002dmenu_002c-completion-style"></span>

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 continues 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 completion 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.

<span id="index-original_002c-completion-style"></span>

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 always added. Note that the style
will be examined with the completer field in the context name set to
correct-`num` or approximate-`num`, where `num` is the number of errors
that were accepted.

<span id="index-packageset_002c-completion-style"></span>

packageset

This style is used when completing arguments of the Debian ‘dpkg’
program. It contains an override for the default package set for a given
context. For example,

<div class="example">

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

</div>

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

<span id="index-path_002c-completion-style"></span>

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 standard locations it will be used as
the default.

<span id="index-path_002dcompletion_002c-completion-style"></span>

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’ inhibits this behaviour for
path components up to the / before the cursor; this overrides 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.

<span id="index-pine_002ddirectory_002c-completion-style"></span>

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.

<span id="index-ports_002c-completion-style"></span>

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’.

<span id="index-prefix_002dhidden_002c-completion-style"></span>

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’.

<span id="index-prefix_002dneeded_002c-completion-style"></span>

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 completion tags.

For command options, this means that the initial ‘-’, ‘+’, or ‘--’ must
be typed explicitly 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.

<span id="index-preserve_002dprefix_002c-completion-style"></span>

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 circumstances. 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.

<span id="index-range_002c-completion-style"></span>

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.

<span id="index-recursive_002dfiles_002c-completion-style"></span>

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 unambiguously 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 completion by prepending the word on the command line
with each directory in the expansion 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,

<div class="example">

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

</div>

If the current directory is /home/pws/zsh/Src, then zle_tr\<TAB> can be
completed to Zle/zle_tricky.c.

<span id="index-regular_002c-completion-style"></span>

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.

<span id="index-rehash_002c-completion-style"></span>

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 penalty for this which is only likely to be
noticeable when directories in the path have slow file access.

<span id="index-remote_002daccess_002c-completion-style"></span>

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.

<span id="index-remove_002dall_002ddups_002c-completion-style"></span>

remove-all-dups

The \_history_complete_word bindable command and the \_history completer
use this to decide if all duplicate matches should be removed, rather
than just consecutive duplicates.

<span id="index-select_002dprompt_002c-completion-style"></span>

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.

<span id="index-select_002dscroll_002c-completion-style"></span>

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.

<span id="index-separate_002dsections_002c-completion-style"></span>

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 ‘manuals.`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. See also insert-sections.

The default for this style is ‘false’.

<span id="index-show_002dambiguity_002c-completion-style"></span>

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.

<span id="index-show_002dcompleter_002c-completion-style"></span>

show-completer

Tested whenever a new completer is tried. If it is ‘true’, the
completion system outputs 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 removed after completion is
finished.

<span id="index-single_002dignored_002c-completion-style"></span>

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 completion is started, making
it easy to select either of them.

<span id="index-sort_002c-completion-style"></span>

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.

<span id="index-special_002ddirs_002c-completion-style"></span>

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’.

<div class="example">

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

</div>

<span id="index-squeeze_002dslashes_002c-completion-style"></span>

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. However, by default the file completion
function behaves as if there were a ‘\*’ between the slashes.

<span id="index-stop_002c-completion-style"></span>

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.

<span id="index-strip_002dcomments_002c-completion-style"></span>

strip-comments

If set to ‘true’, this style causes non-essential comment text to be
removed from completion 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.

<span id="index-subst_002dglobs_002donly_002c-completion-style"></span>

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 globbing, the expansions
will be rejected.

The default for this style is ‘false’.

<span id="index-substitute_002c-completion-style"></span>

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’.

<span id="index-suffix_002c-completion-style"></span>

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 expansion. The default
for this style is ‘true’.

<span id="index-tag_002dorder_002c-completion-style"></span>

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:

<div class="example">

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

</div>

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 context 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 attempt; 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 differently 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 ignore all the completion
functions starting with an underscore the first time completion is
tried:

<div class="example">

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

</div>

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:

<div class="example">

```zsh
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 '???*'
```

</div>

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:

<div class="example">

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

</div>

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 conditions for the use of particular tags. For example:

<div class="example">

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

</div>

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 [Completion
Widgets](Completion-Widgets.html#Completion-Widgets) 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.

<span id="index-urls_002c-completion-style"></span>

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,

<div class="example">

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

</div>

allows completion of all the components of the URL ‘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)’).

<span id="index-use_002dcache_002c-completion-style"></span>

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 directory containing the cache files can
be changed with the cache-path style.

<span id="index-use_002dcompctl_002c-completion-style"></span>

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 completion 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.

<span id="index-use_002dip_002c-completion-style"></span>

use-ip

By default, the function \_hosts that completes host names strips IP
addresses from entries 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).

<span id="index-users_002c-completion-style"></span>

users

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

<span id="index-users_002dhosts_002c-completion-style"></span>

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 commands 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.

<span id="index-users_002dhosts_002dports_002c-completion-style"></span>

users-hosts-ports

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

<span id="index-verbose_002c-completion-style"></span>

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’.

<span id="index-word_002c-completion-style"></span>

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 occasions. If this style is
‘true’, the comparison is instead performed only on the current word.
Hence if completion is performed on another word with the same contents,
completion will not be delayed.

------------------------------------------------------------------------

<span id="Control-Functions"></span> <span
id="Control-Functions-1"></span>

## 20.4 Control Functions

<span id="index-completion-system_002c-choosing-completers"></span>

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
arguments, 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:

<div class="example">

```zsh
zstyle ':completion:*' completer _complete _correct
```

</div>

after calling compinit. The default value for this style is ‘\_complete
\_ignored’, i.e. normally 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 completion is performed in the
context ‘:completion::complete:`...`’.

<span id="index-completion-system_002c-completers"></span>

<span id="index-_005fall_005fmatches"></span>

\_all_matches

This completer can be used to add a string consisting of all other
matches. As it influences 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:

<div class="example">

```zsh
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
```

</div>

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:

<div class="example">

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

</div>

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

<span id="index-_005fapproximate"></span>

\_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 [Filename Generation](Expansion.html#Filename-Generation)
for how errors are counted. Normally this completer will only be tried
after the normal \_complete completer:

<div class="example">

```zsh
zstyle ':completion:*' completer _complete _approximate
```

</div>

This will give correcting completion if and only if normal completion
yields no possible 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 accepted 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 context 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 expensive 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.:

<div class="example">

```zsh
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'
```

</div>

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, \_correct and \_approximate
completers called.

<span id="index-_005fcanonical_005fpaths"></span>

\_canonical_paths \[ -A `var` \] \[ -N \] \[ -MJV12nfX \] `tag` `descr`
\[ `paths` ... \]

This completion function completes all paths given to it, and also tries
to offer completions 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 completed; 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 canonicalizing 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`.

<span id="index-_005fcmdambivalent"></span>

\_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.

<span id="index-_005fcmdstring"></span>

\_cmdstring

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

<span id="index-_005fcomplete"></span>

\_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 mentioned above as
possible arguments to the #compdef tag.

Before trying to find a function for a specific context, \_complete
checks if the parameter ‘compcontext’ is set. Setting ‘compcontext’
allows the usual completion dispatching 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`
indicates 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
system itself but is nonetheless handled when explicitly called.

<span id="index-_005fcorrect"></span>

\_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 \_approximate, but the completer field
in the context name is correct.

For example, with:

<div class="example">

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

</div>

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 errors 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 useless since \_approximate will at least
generate the corrected strings generated by the \_correct completer —
and probably more.

<span id="index-_005fexpand"></span>

\_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 control 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 before the
completion system is started. Note also this completer should be called
before 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.

<span id="index-_005fexpand_005falias"></span>

\_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 [Bindable
Commands](#Bindable-Commands).

<span id="index-_005fextensions"></span>

\_extensions

If the cursor follows the string ‘\*.’, filename extensions are
completed. The extensions are taken from files in current directory or a
directory specified at the beginning of the current word. For exact
matches, completion continues to allow other completers such as \_expand
to expand the pattern. The standard add-space and prefix-hidden styles
are observed.

<span id="index-_005fexternal_005fpwds"></span>

\_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.

<span id="index-_005fhistory"></span>

\_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 command, see [Bindable
Commands](#Bindable-Commands) and [Completion System
Configuration](#Completion-System-Configuration).

<span id="index-_005fignored"></span>

\_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.

<span id="index-_005flist"></span>

\_list

This completer allows the insertion of matches to be delayed until
completion is attempted a second time without the word on the line being
changed. On the first attempt, only the list of matches will be shown.
It is affected by the styles condition and word, see [Completion System
Configuration](#Completion-System-Configuration).

<span id="index-_005fmatch"></span>

\_match

This completer is intended to be used after the \_complete completer. It
behaves similarly but the string on the command line may be a pattern to
match against trial completions. 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 completions 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-unambiguous 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.

<span id="index-_005fmenu"></span>

\_menu

This completer was written as simple example function to show how menu
effect of disabling menu selection 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_COMPLETE option
and does not work with the other menu completion widgets such as
reverse-menu-complete, or accept-and-menu-complete.

<span id="index-_005foldlist"></span>

\_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 [Completion System
Configuration](#Completion-System-Configuration).

<span id="index-_005fprecommand"></span>

\_precommand

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

<span id="index-_005fprefix"></span>

\_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 generate 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:

<div class="example">

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

</div>

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 after 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:

<div class="example">

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

</div>

The add-space style is also respected. If it is set to ‘true’ then
\_prefix will insert 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; otherwise, 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.

<span id="index-_005fuser_005fexpand"></span>

\_user_expand

This completer behaves similarly to the \_expand completer but instead
performs expansions 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 generally 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 contextual 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, followed 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.

------------------------------------------------------------------------

<span id="Bindable-Commands"></span> <span
id="Bindable-Commands-1"></span>

## 20.5 Bindable Commands

<span id="index-completion-system_002c-bindable-commands"></span>

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.

<span id="index-_005fbash_005fcompletions"></span>

\_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 default. To add the rest, the following should be
added to .zshrc after compinit has been run:

<div class="example">

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

</div>

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

<span id="index-_005fcorrect_005ffilename-_0028_005eXC_0029"></span>

\_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.

<span id="index-_005fcorrect_005fword-_0028_005eXc_0029"></span>

\_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.

<span id="index-_005fexpand_005falias-_0028_005eXa_0029"></span>

\_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 controlled 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 expanding it. It leaves the cursor
directly after the completed word so that invoking \_expand_alias once
more will expand the now-complete alias name.

<span id="index-_005fexpand_005fword-_0028_005eXe_0029"></span>

\_expand_word (^Xe)

Performs expansion on the current word: equivalent to the standard
expand-word command, but using the \_expand completer. Before calling
it, the `function` field of the context is set to ‘expand-word’.

<span id="index-_005fgeneric"></span>

\_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:

<div class="example">

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

</div>

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.

<span
id="index-_005fhistory_005fcomplete_005fword-_0028_005ce_002f_0029"></span>

\_history_complete_word (\\e/)

Complete words from the shell’s command history. This uses the list,
remove-all-dups, sort, and stop styles.

<span id="index-_005fmost_005frecent_005ffile-_0028_005eXm_0029"></span>

\_most_recent_file (^Xm)

Complete the name of the most recently modified file matching the
pattern on the command line (which may be blank). If given a numeric
argument `N`, complete the `N`th most recently modified file. Note the
completion, if any, is always unique.

<span id="index-_005fnext_005ftags-_0028_005eXn_0029"></span>

\_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 otherwise not be available. Successive
invocations of the command cycle through all possible sets of tags.

<span id="index-_005fread_005fcomp-_0028_005eX_005eR_0029"></span>

\_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.

<span id="index-_005fcomplete_005fdebug-_0028_005eX_003f_0029"></span>

\_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.

<span id="index-_005fcomplete_005fhelp-_0028_005eXh_0029"></span>

\_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 argument 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 information available from the completion functions called, which in
turn is determined by the user’s own styles and other settings.

<span id="index-_005fcomplete_005fhelp_005fgeneric"></span>

\_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 \_complete_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:

<div class="example">

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

</div>

typing ‘C-x :’ followed by the key sequence for a generic widget will
cause trace output for that widget to be saved to a file.

<span id="index-_005fcomplete_005ftag-_0028_005eXt_0029"></span>

\_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 format 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 parameter $TAGSFILE or $tagsfile respectively. The
corresponding completion tags used are etags and vtags, after emacs and
vi respectively.

------------------------------------------------------------------------

<span id="Completion-Functions"></span> <span
id="Utility-Functions-1"></span>

## 20.6 Utility Functions

<span id="index-completion-system_002c-utility-functions"></span>

Descriptions follow for utility functions that may be useful when
writing completion functions. If functions are installed in
subdirectories, most of these reside in the Base subdirectory. 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 completions and non-zero if no matching
completions could be added.

<span id="index-_005fabsolute_005fcommand_005fpaths"></span>

\_absolute_command_paths

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

<span id="index-_005fall_005flabels"></span>

\_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 `arg`s
passed to the `command`. Normally, they are put directly after the
`command`, but if one of the `arg`s is a single hyphen, they are
inserted directly before 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 command
or by a call to one of the utility functions.

For example:

<div class="example">

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

</div>

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

<span id="index-_005falternative"></span>

\_alternative \[ -O `name` \] \[ -C `name` \] `spec` ...

This function is useful in simple cases where multiple tags are
available. Essentially 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 `spec`s which are of the form:
‘`tag`:`descr`:`action`’. The `tag`s are offered using \_tags and if the
tag is requested, the `action` is executed with the given description
`descr`. The `action`s are those accepted by the \_arguments function
(described below), with the following exceptions:

-   The ‘->`state`’ and ‘=`...`’ forms are not supported.
-   The ‘((a\\:bar b\\:baz))’ form does not need the colon to be
    escaped, since the `spec`s have no colon-separated fields after the
    `action`.

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

<div class="example">

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

</div>

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 additional 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 action.

Like \_tags this function supports the -C option to give a different
name for the argument context field.

<span id="index-_005farguments"></span>

\_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 command 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 options are followed by `spec`s that describe options and
arguments of the analyzed command. 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-letter 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 segment entitled ‘Deriving `spec` forms from the help output’.

-w  
In combination with -s, allow option stacking even if one or more of the
options 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 subsequent 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 depends 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 action.

-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

<div class="example">

```zsh
foobar -x -- -y
```

</div>

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 argument, but ignoring all strings starting with
a hyphen even if they are not described by one of the `optspec`s, the
form is ‘-A "-\*"’.

-O `name`  
Pass the elements of the array `name` as arguments to functions called
to execute `action`s. 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:

<div class="example">

```zsh
r:|[_-]=* r:|=*
```

</div>

-0  
When populating values of the ‘opt_args’ associative array, don’t
backslash-escape colons and backslashes and use NUL rather than colon
for joining multiple values. This option is described in more detail
below, under the heading *`spec`s: actions*.

*`spec`s: overview*

Each of the following forms is a `spec` describing individual sets of
options or arguments 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 position (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 provided. 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
arguments to the option; if it is not present, the option is assumed to
take no arguments.

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
option 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
option (if any) must follow as a *separate* word directly after the
option.

Either of ‘-+`optname`’ and ‘+-`optname`’ can be used to specify that
-`optname` 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
completed option and argument will look like ‘-foo`arg`’.

\-`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 ‘-foo`arg`’ 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
example ‘-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
character 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
ordinary 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
completed as described by the `action`; otherwise, all the words up to
and including a word matching the `pattern` are to be completed using
the `action`.

Multiple colons are treated as for the ‘\*:`...`’ forms for ordinary
arguments: when the `message` is preceded by two colons, the words
special array and the CURRENT special parameter are modified during the
execution 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 arguments 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 options -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 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 argument 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’.

*`spec`s: 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 `action`s 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 `action`s.

The forms for `action` are as follows.

 (single unquoted space)  
This is useful where an argument is required but it is not possible or
desirable to generate matches for it. The `message` will be displayed
but no completions 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:

<div class="example">

```zsh
:foo:(foo bar baz)
```

</div>

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

<div class="example">

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

</div>

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

->`string`  
<span id="index-context_002c-use-of"></span> <span
id="index-line_002c-use-of"></span> <span
id="index-opt_005fargs_002c-use-of"></span>

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 `string`s for which an action is to be
performed. The elements of the array 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, \_arguments returns status zero if it was able to add matches
and non-zero otherwise. However, if the -R option is given, \_arguments
will instead return a status of 300 to indicate that $state is to be
handled.

In addition to $state and $state_descr, \_arguments also sets the global
parameters ‘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 propagating changes in them.

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

<div class="example">

```zsh
local context state state_descr line
typeset -A opt_args
```

</div>

to prevent \_arguments from altering the global environment.

{`eval-string`}  
<span id="index-expl_002c-use-of"></span>

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 restricted range; it is necessary to use this
trick to insert an appropriate command 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 ensure 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, typically 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 arguments 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. By default, all colons and
backslashes in the value are escaped with backslashes, and if an option
has multiple arguments (for example, when using an `optspec` of the form
‘\*`optspec`’), they are joined with (unescaped) colons. However, if the
-0 option was passed, no backslash escaping is performed, and multiple
values are joined with NUL bytes. For example, after ‘zsh -o foo:foo -o
bar:bar -o \<TAB>’, the contents of ‘opt_args’ would be

<div class="example">

```zsh
typeset -A opt_args=( [-o]='foo\:foo:bar\:bar:' )
```

</div>

by default, and

<div class="example">

```zsh
typeset -A opt_args=( [-o]=$'foo:foo\x00bar:bar\x00' )
```

</div>

if \_arguments had been called with the -0 option.

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 string of the
form ‘option`-opt`-`n`’ for the `n`’th argument of the option `-opt`, or
a string of the form ‘argument-`n`’ for the `n`’th argument. For ‘rest’
arguments, 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 ‘option-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 parameter.

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 context. Here it (and not the context
array) should be made local to the calling function to avoid passing
back the modified value and should be initialised to the current value
at the start of the function:

<div class="example">

```zsh
local curcontext="$curcontext"
```

</div>

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 referenced in an exclusion list or a
group name can be used to disambiguate between two forms of the same
option. For example:

<div class="example">

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

</div>

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:

<div class="example">

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

</div>

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 ‘operation–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 separated 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 example:

<div class="example">

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

</div>

This defines two sets. When the command line contains the option ‘-c’,
the ‘-d’ option 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 preceding 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 option 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 provide 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:

<div class="example">

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

</div>

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 description 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:

<div class="example">

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

</div>

so that the above specifications will cause directories to be completed
after ‘--directory’, though not after ‘-C’.

Note also that \_arguments tries to find out automatically if the
argument for an option 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 locale 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 command 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,

<div class="example">

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

</div>

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 option 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
‘--enable-foo’, but the script also accepts the negated form
‘--disable-foo’. To allow completion of the second form:

<div class="example">

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

</div>

*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 treatment 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:

<div class="example">

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

</div>

This describes three options: ‘-l’, ‘-format’, and ‘-copy’. The first
takes one argument 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 arguments. The first is mandatory and will be completed as a
filename. The second is optional (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 describes 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 number`’ but does not offer
completions.

<span id="index-_005fcache_005finvalid"></span>

\_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:

<div class="example">

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

</div>

<span id="index-_005fcall_005ffunction"></span>

\_call_function `return` `name` \[ `arg` ... \]

If a function `name` exists, it is called with the arguments `arg`s. 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.

<span id="index-_005fcall_005fprogram"></span>

\_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 `string`s from the call to \_call_program, or from the style if set,
are concatenated with spaces between them and the resulting 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 (except 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.

<span id="index-_005fcombination"></span>

\_combination \[ -s `pattern` \] `tag` `style` `spec` ... `field` `opts`
...

This function is used to complete combinations of values, for example
pairs of hostnames 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 completions should be generated (presumably not one of the
`field`s 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 required, 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.

<span id="index-_005fcommand_005fnames"></span>

\_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 commands are completed. The - flag is ignored.

<span id="index-_005fcomp_005flocale"></span>

\_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 exported to the environment. Typical usage would be
‘$(\_comp_locale; `command` ...)’.

<span id="index-_005fcompleters"></span>

\_completers \[ -p \]

This function completes names of completers.

-p  
Include the leading underscore (‘\_’) in the matches.

<span id="index-_005fdefault"></span>

\_default

This function corresponds to the -default- special context which is
applied where no completion is defined. It is useful to call it under
certain error conditions such as completion after an unrecognised
subcommand. This applies the concept of graceful degradation to the
completion system, allowing it to fallback on basic completion of
commonly useful things like filenames.

<span id="index-_005fdescribe"></span>

\_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 `opt`s.

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 `completion`
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 possible completions instead of the `completion`
strings from `name1`. The completion list will retain the descriptions
from `name1`. Finally, a set of completion options can appear.

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 completions and if the
descriptions should be shown. Without the ‘-o’ option, only the verbose
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 prefix-needed style.

With the -t option a `tag` can be specified. The default is ‘values’ or,
if the -o option 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.

<span id="index-_005fdescription"></span>

\_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 `spec`s 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 no additional `spec`s are
given but the description in `descr` conforms to a common form then
further escape sequences are set for elements of that description. These
elements correspond to a default (‘%r’) and the remaining initial part
of the description (‘%h’). The form the description takes consists of
specifying the units and range in parentheses and the default value in
square brackets, for example:

<div class="example">

```zsh
_description times expl 'timeout (seconds) (0-60) [20]'
```

</div>

It is possible to use zformat conditional expressions when styling these
elements. So, for example, to add ‘default:’ as a tag but only when
there is a default value to show, the format style might include
‘%(o.default: %o.)’.

If the -x option is given, the description will be passed to compadd
using the -x option 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 array.
Hence it is possible for the completion group to be unsorted by giving
the option ‘-V’, ‘-1V’, or ‘-2V’.

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

<div class="example">

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

</div>

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.

<span id="index-_005fdir_005flist"></span>

\_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.

<span id="index-_005fdispatch"></span>

\_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 described above for compdef) given as
`string`s. The first completion function to be defined 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 `context/command` field (the fourth) of the $curcontext
parameter to the `context` given as the first argument.

<span id="index-_005femail_005faddresses"></span>

\_email_addresses \[ -c \] \[ -n `plugin` \]

Complete email addresses. Addresses are provided by plugins.

-c  
Complete bare localhost@domain.tld addresses, without a name part or a
comment. Without this option, RFC822 ‘`Firstname Lastname`
\<`address`\>’ strings are completed.

-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.

<span id="index-_005ffiles"></span>

\_files

The function \_files is a wrapper around \_path_files. It supports all
of the same functionality, 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.

<span id="index-_005fgnu_005fgeneric"></span>

\_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 completion for
the commands foo and bar, use

<div class="example">

```zsh
compdef _gnu_generic foo bar
```

</div>

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’.

<span id="index-_005fguard"></span>

\_guard \[ `options` \] `pattern descr`

This function displays `descr` if `pattern` matches the string to be
completed. It is intended to be used in the `action` for the
specifications passed to \_arguments and similar 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 conventions 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:

<div class="example">

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

</div>

\_arguments can be made to both display the message ‘numeric value’ and
complete options 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.

<span id="index-_005fmessage"></span>

\_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 generated. 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 argument 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 completion 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.

<span id="index-_005fmulti_005fparts"></span>

\_multi_parts \[ -i \] `sep` `array`

The argument `sep` is a separator character. The `array` may be either
the name of an array 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 array. 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 multiple 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 compadd builtin.

<span id="index-_005fnext_005flabel"></span>

\_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 function. 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_label.

The `option`s 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 determines if tag foo is required at all; the loop over
\_next_label handles any labels defined for the tag in the tag-order
style.

<div class="example">

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

</div>

<span id="index-_005fnormal"></span>

\_normal \[ -P \| -p `precommand` \]

This is the standard function called to handle completion outside any
special -`context`-. 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 \_precommand, 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 command line which allows internal commands (e.g. builtins and
functions) regardless 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.

<span id="index-_005fnumbers"></span>

\_numbers \[ `option` ... \] \[ `description` \] \[ `suffix` ... \]

This can be used where a number is followed by a suffix to indicate the
units. The unit suffixes are completed and can also be included in the
description used when completion is invoked for the preceding number.

In addition to common compadd options, \_numbers accepts the following
options:

-t `tag`  
Specify a tag to use instead of the default of numbers.

-u `units`  
Indicate the default units for the number, e.g. bytes.

-l `min`  
Specify the lowest possible value for the number.

-m `max`  
Specify the highest possible value for the number.

-d `default`  
Specify the default value.

-N  
Allow negative numbers. This is implied if the range includes a
negative.

-f  
Allow decimal numbers.

Where a particular suffix represents the default units for a number, it
should be prefixed with a colon. Additionally, suffixes can be followed
by a colon and a description. So for example, the following allows the
age of something to be specified, either in seconds or with an optional
suffix with a longer unit of time:

<div class="example">

```zsh
_numbers -u seconds age :s:seconds m:minutes h:hours d:days
```

</div>

It is typically helpful for units to be presented in order of magnitude
when completed. To facilitate this, the order in which they are given is
preserved.

When the format style is looked up with the descriptions tag or the tag
specified with -t, the list of suffixes is available as a ‘%x’ escape
sequence. This is in addition to the usual sequences documented under
the format style. The form this list takes can also be configured. To
this end, the format style is first looked up with the tag
unit-suffixes. The retrieved format is applied to each suffix in turn
and the results are then concatenated to form the completed list. For
the unit-suffixes format, ‘%x’ expands to the individual suffix and ‘%X’
to its description. %d’ indicates a default suffix and can be used in a
condition. The index and reverse index are set in ‘%i’ and ‘%r’
respectively and are useful for text included only with the first and
last suffixes in the list. So for example, the following joins the
suffixes together as a comma-separated list:

<div class="example">

```zsh
zstyle ':completion:*:unit-suffixes' format '%x%(r::,)'
```

</div>

<span id="index-_005foptions"></span>

\_options

This can be used to complete the names of shell options. It provides a
matcher specification that ignores a leading ‘no’, ignores underscores
and allows upper-case letters to match their lower-case counterparts
(for example, ‘glob’, ‘noglob’, ‘NO_GLOB’ are all completed). Any
arguments are propagated to the compadd builtin.

<span id="index-_005foptions_005fset"></span> <span
id="index-_005foptions_005funset"></span>

\_options_set and \_options_unset

These functions complete only set or unset options, with the same
matching specification 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 settings in effect before the completion widget
locally sets the options it needs. Hence these functions are not
generally used by the completion system.

<span id="index-_005fparameters"></span>

\_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 judicious use of ‘\*’ in `pattern` is probably
necessary.

All other arguments are passed to the compadd builtin.

<span id="index-_005fpath_005ffiles"></span>

\_path_files

This function is used throughout the completion system to complete
filenames. It allows completion of partial paths. For example, the
string ‘/u/i/s/sig’ may be completed 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 parameter, a literal list of paths enclosed in
parentheses or an absolute pathname.

-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 compadd: ‘-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.

<span id="index-_005fpick_005fvariant"></span>

\_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 arguments
`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.

<span id="index-_005fregex_005farguments"></span>

\_regex_arguments `name` `spec` ...

This function generates a completion function `name` which matches the
specifications `spec`s, a set of regular expressions as described below.
After running \_regex_arguments, the function `name` should be called as
a normal completion function. The pattern to be matched is given by the
contents of the words array up to the current cursor 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 remaining word and any `action`s
for the corresponding patterns are executed. In this case, nothing is
stripped from the command line string. The order of evaluation of the
`action`s can be determined by the tag-order style; the various formats
supported by \_alternative 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 examined.

The argument starting with : is used in the same manner as an argument
to \_alternative.

A component is used as follows: `pattern` is tested to see if the
component already 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 `action`s of the current
and previously matched patterns are ignored even if the following
‘`pattern`’ matches the empty string.

( `spec` )  
Parentheses may be used to groups `spec`s; note each parenthesis is a
single argument to \_regex_arguments.

`spec` #  
This allows any number of repetitions of `spec`.

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

`spec` \| `spec`  
Either of the two `spec`s 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:

<div class="example">

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

</div>

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 recommended in normal use). The first component
matches the command word, which is arbitrary; the second matches any
argument. As the argument is also arbitrary, any following component
would not depend on aaa being present.

<div class="example">

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

</div>

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

<div class="example">

```zsh
_regex_arguments _tst /$'[^\0]#\0'/ \( \ 
    /$'aaa\0'/ :'compadd aaa' \ 
    /$'bbb\0'/ :'compadd bbb' \) \#
```

</div>

In this example, an indefinite number of command arguments may be
completed. Odd arguments 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.

<div class="example">

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

</div>

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

<span id="index-_005fregex_005fwords-_005b-_002dt-term-_005d"></span>

\_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 `description` 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 completed are themselves to be completed. It will be evaluated
in order to avoid problems with quoting. This means that typically it
contains a reference to an array containing 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:

<div class="example">

```zsh
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 "$@"
```

</div>

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.

<span id="index-_005frequested"></span>

\_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:

<div class="example">

```zsh
_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
```

</div>

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 arguments 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:

<div class="example">

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

</div>

If the `command` is not compadd, it must nevertheless be prepared to
handle the same options.

<span id="index-_005fretrieve_005fcache"></span>

\_retrieve_cache `cache_identifier`

This function retrieves completion information from the file given by
`cache_identifier`, 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.

<span id="index-_005fsep_005fparts"></span>

\_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 arrays 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.

<span id="index-_005fsequence"></span>

\_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.

<span id="index-_005fsetup"></span>

\_setup `tag` \[ `group` \]

This function sets up the special parameters used by the completion
system appropriately 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.

<span id="index-_005fstore_005fcache"></span>

\_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 operations are stored in parameters; this
function then dumps the values of those parameters to a file. The data
can then be retrieved quickly from that file via \_retrieve_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 \~/.zcompcache. The remaining `param`s 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 completion data available as parameters. However, in
that case it should call \_cache_invalid 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.

<span id="index-_005ftags"></span>

\_tags \[ \[ -C `name` \] `tag` ... \]

If called with arguments, these are taken to be the names of tags valid
for completions 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 otherwise. 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 restored 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).

<span id="index-_005ftilde_005ffiles"></span>

\_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 command-line does.

<span id="index-_005fvalues"></span>

\_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 argument is used as the character that separates multiple
values. This character is automatically 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 completion 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 before listing the values.

All other arguments describe the possible values and their arguments in
the same format 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:

<div class="example">

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

</div>

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 described 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 function calling \_values should declare the
local parameters state, state_descr, line, context and val_args:

<div class="example">

```zsh
local context state state_descr line
typeset -A val_args
```

</div>

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 values 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 parameter curcontext should be made local instead of
context (as described above).

<span id="index-_005fwanted"></span>

\_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 generation of matches, is
carried out automatically by \_wanted.

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

<div class="example">

```zsh
local expl
_wanted tag expl 'description' \ 
    compadd -- match1 match2...
```

</div>

See also the use of \_wanted in the example function in [Dynamic named
directories](Expansion.html#Dynamic-named-directories).

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 argument context field. The -x option has the same meaning
as for \_description.

<span id="index-_005fwidgets"></span>

\_widgets \[ -g `pattern` \]

This function completes names of zle widgets (see [Zle
Widgets](Zsh-Line-Editor.html#Zle-Widgets)). The `pattern`, if present,
is matched against values of the $widgets special parameter, documented
in [The zsh/zleparameter
Module](Zsh-Modules.html#The-zsh_002fzleparameter-Module).

------------------------------------------------------------------------

<span id="Completion-System-Variables"></span> <span
id="Completion-System-Variables-1"></span>

## 20.7 Completion System Variables

<span id="index-completion-system_002c-variables"></span>

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 preferences 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.

<span id="index-compprefuncs_002c-use-of"></span> <span
id="index-comppostfuncs_002c-use-of"></span>

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 before or after completion has been
tried. A function will only be called once unless it explicitly
reinserts itself into the array.

------------------------------------------------------------------------

<span id="Completion-Directories"></span> <span
id="Completion-Directories-1"></span>

## 20.8 Completion Directories

<span id="index-completion-system_002c-directory-structure"></span>

In the source distribution, the files are contained in various
subdirectories of the Completion directory. They may have been installed
in the same structure, or into one single function 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 directory 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 decide 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 directories, as well as the X directory, may be
useful on your system.

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This document was generated on *May 14, 2022* using [*texi2html
5.0*](http://www.nongnu.org/texi2html/).  
Zsh version 5.9, released on May 14, 2022.
