ZSHCOMPSYS(1)ZSHCOMPSYS(1)NAMEzshcompsys - zsh completion system
DESCRIPTION
This describes the shell code for the `new' completion system, referred
to as compsys. It is written in shell functions based on the features
described in zshcompwid(1).
The features are contextual, sensitive to the point at which completion
is started. Many completions are already provided. For this reason, a
user can perform a great many tasks without knowing any details beyond
how to initialize the system, which is described below in INITIALIZA‐
TION.
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 sub‐
script'.
A full context specification contains other elements, as we shall
describe.
Besides commands names and contexts, the system employs two more con‐
cepts, 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 com‐
mand 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 out‐
put formatting, but also what kinds of completers are used (and in what
order), or which tags are examined. Styles may accept arguments and
are manipulated using the zstyle command described in see zshmod‐
ules(1).
In summary, tags describe what the completion objects are, and style
how they are to be completed. At various points of execution, the com‐
pletion system checks what styles and/or tags are defined for the cur‐
rent context, and uses that to modify its behavior. The full descrip‐
tion of context handling, which determines how tags and other elements
of the context influence the behaviour of styles, is described below in
COMPLETION SYSTEM CONFIGURATION.
When a completion is requested, a dispatcher function is called; see
the description of _main_complete in the list of control functions
below. This dispatcher decides which function should be called to pro‐
duce 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 behav‐
iour and may be bound to keystrokes, are referred to as `wid‐
gets'. These proliferate as new completions are required.
INITIALIZATION
If the system was installed completely, it should be enough to call the
shell function compinit from your initialization file; see the next
section. However, the function compinstall can be run by a user to
configure various aspects of the completion system.
Usually, compinstall will insert code into .zshrc, although if that is
not writable it will save it in another file and tell you that file's
location. Note that it is up to you to make sure that the lines added
to .zshrc are actually run; you may, for example, need to move them to
an earlier place in the file if .zshrc usually returns early. So long
as you keep them all together (including the comment lines at the start
and finish), you can rerun compinstall and it will correctly locate and
modify these lines. Note, however, that any code you add to this sec‐
tion 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 imme‐
diately. 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 men‐
tioned 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 instal‐
lation any time you are being prompted for information, and your .zshrc
will not be altered at all; changes only take place right at the end,
where you are specifically asked for confirmation.
Use of compinit
This section describes the use of compinit to initialize completion for
the current session when called directly; if you have run compinstall
it will be called automatically from your .zshrc.
To initialize the system, the function compinit should be in a direc‐
tory 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 ini‐
tialization.
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
directories that are world- or group-writable or that are not owned by
root or by the current user. If such files or directories are found,
compinit will ask if the completion system should really be used. To
avoid these tests and make all files found be used without asking, use
the option -u, and to make compinit silently ignore all insecure files
and directories use the option -i. This security check is skipped
entirely when the -C option is given.
The security check can be retried at any time by running the function
compaudit. This is the same check used by compinit, but when it is
executed directly any changes to fpath are made local to the function
so they do not persist. The directories to be checked may be passed as
arguments; if none are given, compaudit uses fpath and _compdir to find
completion system directories, adding missing ones to fpath as neces‐
sary. To force a check of exactly the directories currently named in
fpath, set _compdir to an empty string before calling compaudit or
compinit.
Autoloaded files
The convention for autoloaded functions used in completion is that they
start with an underscore; as already mentioned, the fpath/FPATH parame‐
ter must contain the directory in which they are stored. If zsh was
properly installed on your system, then fpath/FPATH automatically con‐
tains 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 subdirecto‐
ries will be added to the path. Furthermore, if the subdirectory Base
has a subdirectory named Core, compinit will add all subdirectories of
the subdirectories is to the path: this allows the functions to be in
the same format as in the zsh source distribution.
When compinit is run, it searches all such files accessible via
fpath/FPATH and reads the first line of each of them. This line should
contain one of the tags described below. Files whose first line does
not start with one of these tags are not considered to be part of the
completion system and will not be treated specially.
The tags are:
#compdef names... [ -[pP] patterns... [ -N names... ] ]
The file will be made autoloadable and the function defined in
it will be called when completing names, each of which is either
the name of a command whose arguments are to be completed or one
of a number of special contexts in the form -context- described
below.
Each name may also be of the form `cmd=service'. When complet‐
ing 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 func‐
tions that can perform many different completions. It is imple‐
mented by setting the parameter $service when calling the func‐
tion; 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 com‐
pletions respectively. Hence -P may be used to specify default
actions.
The option -N is used after a list following -p or -P; it speci‐
fies that remaining words no longer define patterns. It is pos‐
sible to toggle between the three options as many times as nec‐
essary.
#compdef -k style key-sequences...
This option creates a widget behaving like the builtin widget
style and binds it to the given key-sequences, if any. The
style must be one of the builtin widgets that perform comple‐
tion, namely complete-word, delete-char-or-list, expand-or-com‐
plete, expand-or-complete-prefix, list-choices, menu-complete,
menu-expand-or-complete, or reverse-menu-complete. If the
zsh/complist module is loaded (see zshmodules(1)) the widget
menu-select is also available.
When one of the key-sequences is typed, the function in the file
will be invoked to generate the matches. Note that a key will
not be re-bound if 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-sequences ...
This is similar to -k except that only one key-sequences argu‐
ment 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,
#compdef -K _foo_complete complete-word "^X^C" \
_foo_list list-choices "^X^D"
(all on one line) defines a widget _foo_complete for completion,
bound to `^X^C', and a widget _foo_list for listing, bound to
`^X^D'.
#autoload [ options ]
Functions with the #autoload tag are marked for autoloading but
are not otherwise treated specially. Typically they are to be
called from within one of the completion functions. Any options
supplied will be passed to the autoload builtin; a typical use
is +X to force the function to be loaded immediately. Note that
the -U and -z flags are always added implicitly.
The # is part of the tag name and no white space is allowed after it.
The #compdef tags use the compdef function described below; the main
difference is that the name of the function is supplied implicitly.
The special contexts for which completion functions can be defined are:
-array-value-
The right hand side of an array-assignment (`foo=(...)')
-brace-parameter-
The name of a parameter expansion within braces (`${...}')
-assign-parameter-
The name of a parameter in an assignment, i.e. on the left hand
side of an `='
-command-
A word in command position
-condition-
A word inside a condition (`[[...]]')
-default-
Any word for which no other completion is defined
-equal-
A word beginning with an equals sign
-first-
This is tried before any other completion function. The func‐
tion called may set the _compskip parameter to one of various
values: all: no further completion is attempted; a string con‐
taining 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
-math- Inside mathematical contexts, such as `((...))'
-parameter-
The name of a parameter expansion (`$...')
-redirect-
The word after a redirection operator.
-subscript-
The contents of a parameter subscript.
-tilde-
After an initial tilde (`~'), but before the first slash in the
word.
-value-
On the right hand side of an assignment.
Default implementations are supplied for each of these contexts. In
most cases the context -context- is implemented by a corresponding
function _context, for example the context `-tilde-' and the function
`_tilde').
The contexts -redirect- and -value- allow extra context-specific infor‐
mation. (Internally, this is handled by the functions for each context
calling the function _dispatch.) The extra information is added sepa‐
rated by commas.
For the -redirect- context, the extra information is in the form `-re‐
direct-,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. In the case of elements of an associa‐
tive 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 func‐
tions 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 func‐
tion to handle the context.
As an example:
compdef '_files -g "*.log"' '-redirect-,2>,-default-'
completes files matching `*.log' after `2> <TAB>' for any command with
no more specific handler defined.
Also:
compdef _foo -value-,-default-,-default-
specifies that _foo provides completions for the values of parameters
for which no special function has been defined. This is usually han‐
dled by the function _value itself.
The same lookup rules are used when looking up styles (as described
below); for example
zstyle ':completion:*:*:-redirect-,2>,*:*' file-patterns '*.log'
is another way to make completion after `2> <TAB>' complete files
matching `*.log'.
Functions
The following function is defined by compinit and may be called
directly.
compdef [ -an ] function names... [ -[pP] patterns... [ -N names... ] ]
compdef -d names...
compdef -k [ -an ] function style key-sequences...
compdef -K [ -an ] function name style key-sequences ...
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=ser‐
vice'. 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
any shell code. 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 exam‐
ple, to complete files ending in `.h' as arguments to the com‐
mand foo:
compdef '_files -g "*.h"' foo
The option -n prevents any completions already defined for the
command or context from being overwritten.
The option -d deletes any completion defined for the command or
contexts listed.
The names may also contain -p, -P and -N options as described
for the #compdef tag. The effect on the argument list is iden‐
tical, switching between definitions of patterns tried ini‐
tially, patterns tried finally, and normal commands and con‐
texts.
The parameter $_compskip may be set by any function defined for
a pattern context. If it is set to a value containing the sub‐
string `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.
The form with -k defines a widget with the same name as the
function that will be called for each of the key-sequences; this
is like the #compdef -k tag. The function should generate the
completions needed and will otherwise behave like the builtin
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-com‐
plete, 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-sequences, where the latter two
are as for -k and the first must be a unique widget name begin‐
ning with an underscore.
Wherever applicable, the -a option makes the function autoload‐
able, equivalent to autoload -U function.
The function compdef can be used to associate existing completion func‐
tions with new commands. For example,
compdef _pids foo
uses the function _pids to complete process IDs for the command foo.
Note also the _gnu_generic function described below, which can be used
to complete options for commands that understand the `--help' option.
COMPLETION SYSTEM CONFIGURATION
This section gives a short overview of how the completion system works,
and then more detail on how users can configure how and when matches
are generated.
Overview
When completion is attempted somewhere on the command line the comple‐
tion system first works out the context. This takes account of a num‐
ber 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).
This context information is condensed into a string consisting of mul‐
tiple fields separated by colons, referred to simply as `the context'
in the remainder of the documentation. This is used to look up styles,
context-sensitive options that can be used to configure the completion
system. The context used for lookup may vary during the same call to
the completion system.
The context string always consists of a fixed set of fields, separated
by colons and with a leading colon before the first, in the form :com‐
pletion:function:completer:command:argument:tag. These have the fol‐
lowing 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 distribu‐
tion 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 com‐
pleters exist to perform related tasks such as correction, or to
modify the behaviour of a later completer. See the section
`Control Functions' below 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 argu‐
ment we are completing. For command arguments this generally
takes the form argument-n, where n is the number of the argu‐
ment, 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
:completion::complete:dvips:option-o-1:files
says that normal completion was attempted as the first argument to the
option -o of the command dvips:
dvips -o ...
and the completion function will generate filenames.
Usually completion will be tried for all possible tags in an order
given by the completion function. However, this can be altered by
using the tag-order style. Completion is then 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 the section `Bindable Commands' below.
Styles determine such things as how the matches are generated, simi‐
larly to shell options but with much more control. They can have any
number of strings as their value. They are defined with the zstyle
builtin command (see zshmodules(1)).
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 may be matched as a pattern, and the
name of the style itself, which must be given exactly.
For example, many completion functions can generate matches in a simple
and a verbose form and use the verbose style to decide which form
should be used. To make all such functions use the verbose form, put
zstyle ':completion:*' verbose yes
in a startup file (probably .zshrc). This gives the verbose style the
value yes in every context inside the completion system, unless that
context has a more specific definition. It is best to avoid giving the
context as `*' in case the style has some meaning outside the comple‐
tion 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 com‐
pletion for the kill builtin. If the style is set, the builtin lists
full job texts and process command lines; otherwise it shows the bare
job numbers and PIDs. To turn the style off for this use only:
zstyle ':completion:*:*:kill:*' verbose no
For even more control, the style can use one of the tags `jobs' or
`processes'. To turn off verbose display only for jobs:
zstyle ':completion:*:*:kill:*:jobs' verbose no
The -e option to zstyle even allows completion function code to appear
as the argument to a style; this requires some understanding of the
internals of completion functions (see see zshcompwid(1))). For exam‐
ple,
zstyle -e ':completion:*' hosts 'reply=($myhosts)'
This forces the value of the hosts style to be read from the variable
myhosts each time a host name is needed; this is useful if the value of
myhosts can change dynamically. For 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. More precisely, strings are pre‐
ferred over patterns (for example, `:completion::complete:foo' is more
specific than `:completion::complete:*'), and longer patterns are pre‐
ferred over shorter patterns.
Style names like those of tags are arbitrary and depend on the comple‐
tion function. However, the following two sections list some of the
most common tags and styles.
Standard Tags
Some of the following are only used when looking up particular styles
and do not refer to a type of match.
accounts
used to look up the users-hosts style
all-expansions
used by the _expand completer when adding the single string con‐
taining all possible expansions
all-files
for the names of all files (as distinct from a particular sub‐
set, see the globbed-files tag).
arguments
for arguments to a command
arrays for names of array parameters
association-keys
for keys of associative arrays; used when completing inside a
subscript to a parameter of this type
bookmarks
when completing bookmarks (e.g. for URLs and the zftp function
suite)
builtins
for names of builtin commands
characters
for single characters in arguments of commands such as stty.
Also used when completing character classes after an opening
bracket
colormapids
for X colormap ids
colors for color names
commands
for names of external commands. Also used by complex commands
such as cvs when completing names subcommands.
contexts
for contexts in arguments to the zstyle builtin command
corrections
used by the _approximate and _correct completers for possible
corrections
cursors
for cursor names used by X programs
default
used in some contexts to provide a way of supplying a default
when more specific tags are also valid. Note that this tag is
used when only the function field of the context name is set
descriptions
used when looking up the value of the format style to generate
descriptions for types of matches
devices
for names of device special files
directories
for names of directories
directory-stack
for entries in the directory stack
displays
for X display names
domains
for network domains
expansions
used by the _expand completer for individual words (as opposed
to the complete set of expansions) resulting from the expansion
of a word on the command line
extensions
for X server extensions
file-descriptors
for numbers of open file descriptors
files the generic file-matching tag used by functions completing file‐
names
fonts for X font names
fstypes
for file system types (e.g. for the mount command)
functions
names of functions -- normally shell functions, although certain
commands may understand other kinds of function
globbed-files
for filenames when the name has been generated by pattern match‐
ing
groups for names of user groups
history-words
for words from the history
hosts for hostnames
indexes
for array indexes
jobs for jobs (as listed by the `jobs' builtin)
interfaces
for network interfaces
keymaps
for names of zsh keymaps
keysyms
for names of X keysyms
libraries
for names of system libraries
limits for system limits
local-directories
for names of directories that are subdirectories of the current
working directory when completing arguments of cd and related
builtin commands (compare path-directories)
manuals
for names of manual pages
mailboxes
for e-mail folders
maps for map names (e.g. NIS maps)
messages
used to look up the format style for messages
modifiers
for names of X modifiers
modules
for modules (e.g. zsh modules)
my-accounts
used to look up the users-hosts style
named-directories
for named directories (you wouldn't have guessed that, would
you?)
names for all kinds of names
newsgroups
for USENET groups
nicknames
for nicknames of NIS maps
options
for command options
original
used by the _approximate, _correct and _expand completers when
offering the original string as a match
other-accounts
used to look up the users-hosts style
packages
for packages (e.g. rpm or installed Debian packages)
parameters
for names of parameters
path-directories
for names of directories found by searching the cdpath array
when completing arguments of cd and related builtin commands
(compare local-directories)
paths used to look up the values of the expand, ambiguous and spe‐
cial-dirs styles
pods for perl pods (documentation files)
ports for communication ports
prefixes
for prefixes (like those of a URL)
printers
for print queue names
processes
for process identifiers
processes-names
used to look up the command style when generating the names of
processes for killall
sequences
for sequences (e.g. mh sequences)
sessions
for sessions in the zftp function suite
signals
for signal names
strings
for strings (e.g. the replacement strings for the cd builtin
command)
styles for styles used by the zstyle builtin command
suffixes
for filename extensions
tags for tags (e.g. rpm tags)
targets
for makefile targets
time-zones
for time zones (e.g. when setting the TZ parameter)
types for types of whatever (e.g. address types for the xhost command)
urls used to look up the urls and local styles when completing URLs
users for usernames
values for one of a set of values in certain lists
variant
used by _pick_variant to look up the command to run when deter‐
mining what program is installed for a particular command name.
visuals
for X visuals
warnings
used to look up the format style for warnings
widgets
for zsh widget names
windows
for IDs of X windows
zsh-options
for shell options
Standard Styles
Note that the values of several of these styles represent boolean val‐
ues. 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 corre‐
sponding to a type of match, and if no style was found, for the default
tag. The most notable styles of this type are menu, list-colors and
styles controlling completion listing such as list-packed and
last-prompt). When tested for the default tag, only the function field
of the context will be set so that a style using the default tag will
normally be defined along the lines of:
zstyle ':completion:*:default' menu ...
accept-exact
This is tested for the default tag in addition to the tags valid
for the current 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 other‐
wise 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 $foobar. If the style is set to `continue',
_expand will add the expansion as a match and the completion
system will also be allowed to continue.
add-space
This style is used by the _expand completer. If it is true (the
default), a space will be inserted after all words resulting
from the expansion, or a slash in the case of directory names.
If the value is `file', the completer will only add a space to
names of existing files. Either a boolean true or the value
`file' may be combined with `subst', in which case the completer
will not add a space to words generated from the expansion of a
substitution of the form `$(...)' or `${...}'.
The _prefix completer uses this style as a simple boolean value
to decide if a space should be inserted before the suffix.
ambiguous
This applies when completing non-final components of filename
paths, in other words those with a trailing slash. If it is
set, the cursor is left after the first ambiguous component,
even if menu completion is in use. The style is always tested
with the paths tag.
assign-list
When completing after an equals sign that is being treated as an
assignment, the completion system normally completes only one
filename. In some cases the value may be a list of filenames
separated by colons, as with PATH and similar parameters. This
style can be set to a list of patterns matching the names of
such parameters.
The default is to complete lists when the word on the line
already contains a colon.
auto-description
If set, this style's value will be used as the description for
options that are not described by the completion functions, but
that have exactly one argument. The sequence `%d' in the value
will be replaced by the description for this argument. Depend‐
ing on personal preferences, it may be useful to set this style
to something like `specify: %d'. Note that this may not work
for some commands.
avoid-completer
This is used by the _all_matches completer to decide if the
string consisting of all matches should be added to the list
currently being generated. Its value is a list of names of com‐
pleters. If any of these is the name of the completer that gen‐
erated the matches in this completion, the string will not be
added.
The default value for this style is `_expand _old_list _correct
_approximate', i.e. it contains the completers for which a
string with all matches will almost never be wanted.
cache-path
This style defines the path where any cache files containing
dumped completion data are stored. It defaults to `$ZDOT‐
DIR/.zcompcache', or `$HOME/.zcompcache' if $ZDOTDIR is not
defined. The completion cache will not be used unless the
use-cache style is set.
cache-policy
This style defines the function that will be used to determine
whether a cache needs rebuilding. See the section on the
_cache_invalid function below.
call-command
This style is used in the function for commands such as make and
ant where calling the command directly to generate matches suf‐
fers problems such as being slow or, as in the case of make can
potentially causes actions in the makefile to be executed. If it
is set to `true' the command is called to generate matches. The
default value of this style is `false'.
command
In many places, completion functions need to call external com‐
mands 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 com‐
mand 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.
command-path
This is a list of directories to search for commands to com‐
plete. The default for this style is the value of the special
parameter path.
commands
This is used by the function completing sub-commands for the
system initialisation scripts (residing in /etc/init.d or some‐
where not too far away from that). Its values give the default
commands to complete for those commands for which the completion
function isn't able to find them out automatically. The default
for this style are the two strings `start' and `stop'.
complete
This is used by the _expand_alias function when invoked as a
bindable command. If it set to `true' and the word on the com‐
mand line is not the name of an alias, matching alias names will
be completed.
complete-options
This is used by the completer for cd, chdir and pushd. For
these commands a - is used to introduce a directory stack entry
and completion of these is far more common than completing
options. Hence unless the value of this style is true options
will not be completed, even after an initial -. If it is true,
options will be completed after an initial - unless there is a
preceeding -- on the command line.
completer
The strings given as the value of this style provide the names
of the completer functions to use. The available completer func‐
tions are described in the section `Control Functions' below.
Each string may be either the name of a completer function or a
string of the form `function:name'. In the first case the com‐
pleter field of the context will contain the name of the com‐
pleter without the leading underscore and with all other under‐
scores 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:
zstyle ':completion:*' completer _complete _complete:-foo
Here, completion will call the _complete completer twice, once
using `complete' and once using `complete-foo' in the completer
field of the context. Normally, using the same completer more
than once only makes sense when used with the `functions:name'
form, because otherwise the context name will be the same in all
calls to the 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.
condition
This style is used by the _list completer function to decide if
insertion of matches should be delayed unconditionally. The
default is `true'.
delimiters
This style is used when adding a delimiter for use with history
modifiers or glob qualifiers that have delimited arguments. It
is an array of preferred delimiters to add. Non-special charac‐
ters 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.
disabled
If this is set to `true', the _expand_alias completer and bind‐
able command will try to expand disabled aliases, too. The
default is `false'.
domains
A list of names of network domains for completion. If this is
not set, domain names will be taken from the file
/etc/resolv.conf.
expand This style is used when completing strings consisting of multi‐
ple parts, such as path names.
If one of its values is the string `prefix', the partially typed
word from the line will be expanded as far as possible even if
trailing parts cannot be completed.
If one of its values is the string `suffix', matching names for
components after the first ambiguous one will also be added.
This means that the resulting string is the longest unambiguous
string possible. However, menu completion can be used to cycle
through all matches.
fake This style may be set for any completion context. It specifies
additional strings that will always be completed in that con‐
text. 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.
fake-always
This works identically to the fake style except that the
ignored-patterns style is not applied to it. This makes it pos‐
sible to override a set of matches completely by setting the
ignored patterns to `*'.
The following shows a way of supplementing any tag with arbi‐
trary 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.
zstyle ':completion::complete:cd:*' tag-order \
'named-directories:-mine:extra\ directories
named-directories:-normal:named\ directories *'
zstyle ':completion::complete:cd:*:named-directories-mine' \
fake-always mydir1 mydir2
zstyle ':completion::complete:cd:*:named-directories-mine' \
ignored-patterns '*'
fake-files
This style is used when completing files and looked up without a
tag. Its values are of the form `dir:names...'. This will add
the names (strings separated by spaces) as possible matches when
completing in the directory dir, even if no such files really
exist. The dir may be a pattern; pattern characters or colons
in dir should be quote with a backslash to be treated literally.
This can be useful on systems that support special filesystems
whose top-level pathnames can not be listed or generated with
glob patterns. 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 filing system.
fake-parameters
This is used by the completion function for parameter names.
Its values are names of parameters that might not yet be set but
should be completed nonetheless. Each name may also be followed
by a colon and a string specifying the type of the parameter
(like `scalar', `array' or `integer'). If the type is given,
the name will only be completed if parameters of that type are
required in the particular context. Names for which no type is
specified will always be completed.
file-list
This style controls whether files completed using the standard
builtin mechanism are to be listed with a long list similar to
ls -l. Note that this feature uses the shell module zsh/stat
for file information; this loads the builtin stat which will
replace any external stat executable. To avoid this the follow‐
ing code can be included in an initialization file:
zmodload -i zsh/stat
disable stat
The style may either be set to a true value (or `all'), or one
of the values `insert' or `list', indicating that files are to
be listed in long format in all circumstances, or when attempt‐
ing 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,
zstyle ':completion:*' file-list list=20 insert=10
specifies that long format will be used when listing up to 20
files or inserting a file with up to 10 matches (assuming a
listing is to be shown at all, for example on an ambiguous com‐
pletion), else short format will be used.
zstyle -e ':completion:*' file-list '(( ${+NUMERIC} )) && reply=(true)'
specifies that long format will be used any time a numeric argu‐
ment is supplied, else short format.
file-patterns
This is used by the standard function for completing filenames,
_files. If the style is unset up to three tags are offered,
`globbed-files',`directories' and `all-files', depending on the
types of files expected by the caller of _files. The first two
(`globbed-files' and `directories') are normally offered
together to make it easier to complete files in sub-directories.
The file-patterns style provides alternatives to the default
tags, which are not used. Its value consists of elements of the
form `pattern:tag'; each string may contain any number of such
specifications separated by spaces.
The pattern is a pattern that is to be used to generate file‐
names. 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 distin‐
guishable from the colon before the tag. If more than one pat‐
tern is needed, the patterns can be given inside braces, sepa‐
rated by commas.
The tags of all strings in the value will be offered by _files
and used when looking up other styles. Any tags in the same
word will be offered at the same time and 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. If the description given
here contains itself a `%d', that is replaced with the descrip‐
tion supplied by the completion function.
For example, to make the rm command first complete only names of
object files and then the names of all files if there is no
matching object file:
zstyle ':completion:*:*:rm:*' file-patterns \
'*.o:object-files' '%p:all-files'
To alter the default behaviour of file completion -- offer files
matching a pattern and directories on the first attempt, then
all files -- to offer only matching files on the first attempt,
then directories, and finally all files:
zstyle ':completion:*' file-patterns \
'%p:globbed-files' '*(-/):directories' '*:all-files'
This works even where there is no special pattern: _files
matches all files using the pattern `*' at the first step and
stops when it sees this pattern. Note also it will never try a
pattern more than once for a single completion attempt.
During the execution of completion functions, the EXTENDED_GLOB
option is in effect, so the characters `#', `~' and `^' have
special meanings in the patterns.
file-sort
The standard filename completion function uses this style with‐
out 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 modifi‐
cation 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.
filter This is used by the LDAP plugin for e-mail address completion 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.
force-list
This forces a list of completions to be shown at any point where
listing is done, even in cases where the list would usually be
suppressed. For example, normally the list is only shown if
there are at least two different matches. By setting this style
to `always', the list will always be shown, even if there is
only a single match that will immediately be accepted. The
style may also be set to a number. In this case the list will
be shown if there are at least that many matches, even if they
would all insert the same string.
This style is tested for the default tag as well as for each tag
valid for the current completion. Hence the listing can be
forced only for certain types of match.
format If this is set for the descriptions tag, its value is used as a
string to display above matches in completion lists. The
sequence `%d' in this string will be replaced with a short
description of what these matches are. This string may also
contain the sequences to specify output attributes, such as
`%B', `%S' and `%{...%}'.
The style is tested with each tag valid for the current comple‐
tion before it is tested for the descriptions tag. Hence dif‐
ferent 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 cus‐
tomised by setting this style for the messages tag. Here, the
`%d' is replaced with a message given by the completion func‐
tion.
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 zfor‐
mat builtin command from the zsh/zutil module, see zshmod‐
ules(1).
glob This is used by the _expand completer. If it is set to `true'
(the default), globbing will be attempted on the words resulting
from a previous substitution (see the substitute style) or else
the original string from the line.
global If this is set to `true' (the default), the _expand_alias com‐
pleter and bindable command will try to expand global aliases.
group-name
The completion system can group different types of matches,
which appear in separate lists. This style can be used to give
the names of groups for particular tags. For example, in com‐
mand 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:
zstyle ':completion:*:*:-command-:*:commands' group-name commands
zstyle ':completion:*:*:-command-:*:functions' group-name functions
As a consequence, any match with the same tag will be displayed
in the same group.
If the name given is the empty string the name of the tag for
the matches will be used as the name of the group. So, to have
all different types of matches displayed separately, one can
just set:
zstyle ':completion:*' group-name ''
All matches for which no group name is defined will be put in a
group named -default-.
group-order
This style is additional to the group-name style to specify the
order for display of the groups defined by that style (compare
tag-order, which determines which 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:
zstyle ':completion:*:*:-command-:*' group-order \
builtins functions commands
groups A list of names of UNIX groups. If this is not set, group names
are taken from the YP database or the file `/etc/group'.
hidden If this is set to true, matches for the given context will not
be listed, although any description for the matches set with the
format style will be shown. If it is set to `all', not even the
description will be displayed.
Note that the matches will still be completed; they are just not
shown in the list. To avoid having matches considered as possi‐
ble completions at all, the tag-order style can be modified as
described below.
hosts A list of names of hosts that should be completed. If this is
not set, hostnames are taken from the file `/etc/hosts'.
hosts-ports
This style is used by commands that need or accept hostnames and
network ports. The strings in the value should be of the form
`host:port'. Valid ports are determined by the presence of
hostnames; multiple ports for the same host may appear.
ignore-line
This is tested for each tag valid for the current completion.
If it is set to `true', none of the words that are already on
the line will be considered as possible completions. If it is
set to `current', the word the cursor is on will not be consid‐
ered 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',
no word apart from the current one will be considered as a pos‐
sible completion.
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.
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.
extra-verbose
If set, the completion listing is more verbose at the cost of a
probable decrease in completion speed. Completion performance
will suffer if this style is set to `true'.
ignored-patterns
A list of patterns; any trial completion matching one of the
patterns will be excluded from consideration. The _ignored com‐
pleter 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.
insert This style is used by the _all_matches completer to decide
whether to insert the list of all matches unconditionally
instead of adding the list as another match.
insert-ids
When completing process IDs, for example as arguments to the
kill and wait builtins the name of a command may be converted to
the appropriate process ID. A problem arises when the process
name typed is not unique. By default (or if this style is set
explicitly to `menu') the name will be converted immediately to
a set of possible IDs, and menu completion will be started to
cycle through them.
If the value of the style is `single', the shell will wait until
the user has typed enough to make the command unique before con‐
verting the name to an ID; attempts at completion will be unsuc‐
cessful until that point. If the value is any other string,
menu completion will be started when the string typed by the
user is longer than the common prefix to the corresponding IDs.
insert-tab
If this is set to `true', the completion system will insert a
TAB character (assuming that was used to start completion)
instead of performing completion when there is no non-blank
character to the left of the cursor. If it is set to `false',
completion will be done even there.
The value may also contain the substrings `pending' or `pend‐
ing=val'. In this case, the typed character will be inserted
instead of staring 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 guaran‐
teed on all platforms.
The default value of this style is `true' except for completion
within vared builtin command where it is `false'.
insert-unambiguous
This is used by the _match and _approximate completers. These
completers are often used with menu completion since the word
typed may bear little resemblance to the final completion. How‐
ever, 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.
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 com‐
pleters may be called.
last-prompt
This is a more flexible form of the ALWAYS_LAST_PROMPT option.
If it is true, the completion system will try to return the cur‐
sor to the previous command line after displaying a completion
list. It is tested for all tags valid for the current comple‐
tion, then the default tag. The cursor will be moved back to
the previous line if this style is `true' for all types of
match. Note that unlike the ALWAYS_LAST_PROMPT option this is
independent of the numeric prefix argument.
known-hosts-files
This style should contain a list of files to search for host
names and (if the use-ip style is set) IP addresses in a format
compatible with ssh known_hosts files. If it is not set, the
files /etc/ssh/ssh_known_hosts and ~/.ssh/known_hosts are used.
list This style is used by the _history_complete_word bindable com‐
mand. 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:his‐
tory-words'.
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 sec‐
tion `The zsh/complist Module' in zshmodules(1), but the syntax
is the same.
If this style is set for the default tag, the strings in the
value are taken as specifications that are to be used every‐
where. 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 pos‐
sible to use group names specified explicitly by the group-name
tag together with the `(group)' syntax allowed by the ZLS_COLORS
and ZLS_COLOURS parameters and simply using the default tag.
It is possible to use any color specifications already set up
for the GNU version of the ls command:
zstyle ':completion:*:default' list-colors ${(s.:.)LS_COLORS}
The default colors are the same as for the GNU ls command and
can be obtained by setting the style to an empty string (i.e.
'').
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.
list-packed
This is tested for each tag valid in the current context as well
as the default tag. If it is set to `true', the corresponding
matches appear in listings as if the LIST_PACKED option were
set. If it is set to `false', they are listed normally.
list-prompt
If this style is set for the default tag, completion lists that
don't fit on the screen can be scrolled (see the description of
the zsh/complist module in zshmodules(1)). The value, if not
the empty string, will be displayed after every screenful and
the shell will prompt for a key press; if the style is set to
the empty string, a default prompt will be used.
The value may contain the escape sequences: `%l' or `%L', which
will be replaced by the number of the last line displayed and
the total number of lines; `%m' or `%M', the number of the last
match shown and the total number of matches; and `%p' and `%P',
`Top' when at the beginning of the list, `Bottom' when at the
end and the position shown as a percentage of the total length
otherwise. In each case the form with the uppercase letter will
be replaced by a string of fixed width, padded to the right
with spaces, while the lowercase form will be replaced by a
variable width string. As in other prompt strings, the escape
sequences `%S', `%s', `%B', `%b', `%U', `%u' for entering and
leaving the display modes standout, bold and underline are also
available, as is the form `%{...%}' for enclosing escape
sequences which display with zero width.
After deleting this prompt the variable LISTPROMPT should be
unset for the the removal to take effect.
list-rows-first
This style is tested in the same way as the list-packed style
and determines whether matches are to be listed in a rows-first
fashion as if the LIST_ROWS_FIRST option were set.
list-suffixes
This style is used by the function that completes filenames. If
it is true, and completion is attempted on a string containing
multiple partially typed pathname components, all ambiguous com‐
ponents will be shown. Otherwise, completion stops at the first
ambiguous component.
list-separator
The value of this style is used in completion listing to sepa‐
rate the string to complete from a description when possible
(e.g. when completing options). It defaults to `--' (two
hyphens).
local This is for use with functions that complete URLs for which the
corresponding files are available directly from the filing sys‐
tem. 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:
zstyle ':completion:*' local toast \
/var/http/public/toast public_html
Completion after `http://toast/stuff/' will look for files in
the directory /var/http/public/toast/stuff, while completion
after `http://toast/~yousir/' will look for files in the direc‐
tory ~yousir/public_html.
mail-directory
If set, zsh will assume that mailbox files can be found in the
directory specified. It defaults to `~/Mail'.
match-original
This is used by the _match completer. If it is set to only,
_match will try to 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.
matcher
This style is tested separately for each tag valid in the cur‐
rent context. Its value is added to any match specifications
given by the matcher-list style. It should be in the form
described in the section `Matching Control' in zshcompwid(1).
matcher-list
This style can be set to a list of match specifications that are
to be applied everywhere. Match specifications are described in
the section `Matching Control' in zshcompwid(1). 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:
zstyle ':completion:*' matcher-list '' 'm:{a-zA-Z}={A-Za-z}'
By default each specification replaces the previous one; how‐
ever, if a specification is prefixed with +, it is added to the
existing list. Hence it is possible to create increasingly gen‐
eral specifications without repetition:
zstyle ':completion:*' matcher-list '' '+m{a-Z}={A-Z}' '+m{A-Z}={a-z}'
It is possible to create match specifications valid for particu‐
lar completers by using the third field of the context. For
example, to use the completers _complete and _prefix but only
allow case-insensitive completion with _complete:
zstyle ':completion:*' completer _complete _prefix
zstyle ':completion:*:complete:*' matcher-list \
'' 'm:{a-zA-Z}={A-Za-z}'
User-defined names, as explained for the completer style, are
available. This makes it possible to try the same completer
more than once with different match specifications each time.
For example, to try normal completion without a match specifica‐
tion, then normal completion with case-insensitive matching,
then correction, and finally partial-word completion:
zstyle ':completion:*' completer _complete _correct _complete:foo
zstyle ':completion:*:complete:*' matcher-list \
'' 'm:{a-zA-Z}={A-Za-z}'
zstyle ':completion:*:foo:*' matcher-list \
'm:{a-zA-Z}={A-Za-z} r:|[-_./]=* r:|=*'
If the style is unset in any context no match specification is
applied. Note also that some completers such as _correct and
_approximate do not use the match specifications at all, though
these completers will only ever called once even if the
matcher-list contains more than one element.
Where multiple specifications are useful, note that the entire
completion is done for each element of matcher-list, which can
quickly reduce the shell's performance. As a rough rule of
thumb, one to three strings will give acceptable performance.
On the other hand, putting multiple space-separated values into
the same string does not have an appreciable impact on perfor‐
mance.
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.
max-errors
This is used by the _approximate and _correct completer func‐
tions to determine the maximum number of errors to allow. The
completer will try to generate completions by first allowing one
error, then two errors, and so on, until either a match or
matches were found or the maximum number of errors given by this
style has been reached.
If the value for this style contains the string `numeric', the
completer function will take any numeric argument as the maximum
number of errors allowed. For example, with
zstyle ':completion:*:approximate:::' max-errors 2 numeric
two errors are allowed if no numeric argument is given, but with
a numeric argument of six (as in `ESC-6 TAB'), up to six errors
are accepted. Hence with a value of `0 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'.
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.
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' (Typi‐
cally, the value `select=long-list' described later is more use‐
ful as it provides control over scrolling.)
Similarly, with any of the `false' values (as in `no=10'), menu
completion will not be used if there are num or more matches.
The value of this widget also controls menu selection, as imple‐
mented 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 wid‐
get only performs listing, use the value `select=long-list'.
To turn on menu completion or menu selection when a 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 interac‐
tive mode to be entered immediately when menu selection is
started; see the description of the zsh/complist module in zsh‐
modules(1).RE for a description of interactive mode. Including
the string `search' does the same for incremental search mode.
To select backward incremental search, include the string
`search-backward'. )
muttrc If set, gives the location of the mutt configuration
file. It defaults to `~/.muttrc'.
numbers
This is used with the jobs tag. If it is `true', the
shell will complete job numbers instead of the shortest
unambiguous prefix of the job command text. If the value
is a number, job numbers will only be used if that many
words from the job descriptions are required to resolve
ambiguities. For example, if the value is `1', strings
will only be used if all jobs differ in the first word on
their command lines.
old-list
This is used by the _oldlist completer. If it is set to
`always', then standard 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 list‐
ing.
For example, suppose you type ^Xc to use the _cor‐
rect_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 set‐
ting this style to _match, the list of matches generated
on the first attempt will be used again.
old-matches
This is used by the _all_matches completer to decide if
an old list of matches should be used if one exists.
This is selected by one of the `true' values or by the
string `only'. If the value is `only', _all_matches will
only use an old list and won't have any effect on the
list of matches currently being generated.
If this style is set it is generally unwise to call the
_all_matches completer 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.
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.
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.
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,
zstyle ':completion:*:complete:dpkg:option--status-1:*' \
packageset avail
causes available packages, rather than only installed
packages, to be completed for `dpkg --status'.
path The function that completes color names uses this style
with the colors tag. The value should be the pathname of
a file containing color names in the format of an X11
rgb.txt file. If the style is not set but this file is
found in one of various standard locations it will be
used as the default.
pine-directory
If set, specifies the directory containing PINE mailbox
files. There is no default, since recursively searching
this directory is inconvenient for anyone who doesn't use
PINE.
ports A list of Internet service names (network ports) to com‐
plete. If this is not set, service names are taken from
the file `/etc/services'.
prefix-hidden
This is used for certain completions which share a common
prefix, for example command options beginning with
dashes. If it is `true', the prefix will not be shown in
the list of matches.
The default value for this style is `false'.
prefix-needed
This, too, is used 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. In the case of command
options, this means that the initial `-', `+', or `--'
must be typed explicitly before option names will be com‐
pleted.
The default value for this style is `true'.
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.
range This is used by the _history completer and the _his‐
tory_complete_word bindable command to decide which words
should be completed.
If it is a singe 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 was
been found, or max words have been tried.
The default is to complete all words from the history at
once.
regular
This style is used by the _expand_alias completer and
bindable command. If set to `true' (the default), regu‐
lar aliases will be expanded but only in command posi‐
tion. If it is set to `false', regular aliases will
never be expanded. If it is set to `always', regular
aliases will be expanded even if not in command position.
rehash If this is set when completing external commands, the
internal list (hash) of commands will be updated for each
search by issuing the rehash command. There is a speed
penalty for this which is only likely to be noticeable
when directories in the path have slow file access.
remote-access
If set to false, certain commands will be prevented from
making Internet connections to retrieve remote informa‐
tion. 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 unneces‐
sarily.
remove-all-dups
The _history_complete_word bindable command and the _his‐
tory completer use this to decide if all duplicate
matches should be removed, rather than just consecutive
duplicates.
select-prompt
If this is set for the default tag, its value will be
displayed during menu selection (see the menu style
above) when the completion list does not fit on the
screen as a whole. The same escapes as for the
list-prompt style are understood, except that the numbers
refer to the match or line the mark is on. A default
prompt is used when the value is the empty string.
select-scroll
This style is tested for the default tag and determines
how a completion list is scrolled during a menu selection
(see the menu style above) when the completion list does
not fit on the screen as a whole. If the value is `0'
(zero), the list is scrolled by half-screenfuls; if it is
a positive integer, the list is scrolled by the given
number of lines; if it is a negative number, the list is
scrolled by a screenful minus the absolute value of the
given number of lines. The default is to scroll by sin‐
gle lines.
separate-sections
This style is used with the manuals tag when completing
names of manual pages. If it is `true', entries for dif‐
ferent sections are added separately using tag names of
the form `manual.X', where X is the section number. When
the group-name style is also in effect, pages from dif‐
ferent 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 differ‐
ent dictionary databases to be added separately. The
default for this style is `false'.
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 comple‐
tions are found and is removed after completion is fin‐
ished.
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.
sort Many completion widgets call _description at some point
which decides whether the matches are added sorted or
unsorted (often indirectly via _wanted or _requested).
This style can be set explicitly to one of the usual true
or false values as an override. 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.
If the calling widget explicitly requests unsorted
matches, this is usually honoured. However, the default
(unsorted) behaviour of completion for the command his‐
tory 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 con‐
taining all possible expansions.
special-dirs
Normally, the completion code will not produce the direc‐
tory names `.' and `..' as possible completions. If this
style is set to `true', it will add both `.' and `..' as
possible completions; if it is set to `..', only `..'
will be added.
The following example sets special-dirs to `..' when the
current prefix is empty, is a single `.', or consists
only of a path beginning with `../'. Otherwise the value
is `false'.
zstyle -e ':completion:*' special-dirs \
'[[ $PREFIX = (../)#(|.|..) ]] && reply=(..)'
squeeze-slashes
If set to `true', sequences of slashes in filename paths
(for example in `foo//bar') will be treated as a single
slash. This is the usual behaviour of UNIX paths. How‐
ever, by default the file completion function behaves as
if there were a `*' between the slashes.
stop If set to `true', the _history_complete_word bindable
command will stop once when reaching the beginning or end
of the history. Invoking _history_complete_word will
then wrap around to the opposite end of the history. If
this style is set to `false' (the default), _history_com‐
plete_word will loop immediately as in a menu completion.
strip-comments
If set to `true', this style causes non-essential comment
text to be removed from completion matches. Currently it
is only used when completing e-mail addresses where it
removes any display name from the addresses, cutting them
down to plain user@host form.
subst-globs-only
This is used by the _expand completer. If it is set to
`true', the expansion will only be used if it resulted
from globbing; hence, if expansions resulted from the use
of the substitute style described below, but these were
not further changed by globbing, the expansions will be
rejected.
The default for this style is `false'.
substitute
This boolean style controls whether the _expand completer
will first try to expand all substitutions in the string
(such as `$(...)' and `${...}').
The default is `true'.
suffix This is used by the _expand completer if the word starts
with a tilde or contains a parameter expansion. If it is
set to `true', the word will only be expanded if it
doesn't have a suffix, i.e. if it is something like
`~foo' or `$foo' rather than `~foo/' or `$foo/bar',
unless that suffix itself contains characters eligible
for expansion. The default for this style is `true'.
tag-order
This provides a mechanism for sorting how the tags avail‐
able in a particular context will be used.
The values for the style are sets of space-separated
lists of tags. The tags in each value will be tried at
the same time; if no match is found, the next value is
used. (See the file-patterns style for an exception to
this behavior.)
For example:
zstyle ':completion:*:complete:-command-:*' tag-order \
'commands functions'
specifies that completion in command position first
offers external commands and shell functions. Remaining
tags will be tried if no completions are found.
In addition to tag names, each string in the value may
take one of the following forms:
- If any value consists of only a hyphen, then only
the tags specified in the other values are gener‐
ated. Normally all tags not explicitly selected
are tried last if the specified tags fail to gen‐
erate any matches. This means that a single value
consisting only of a single hyphen turns off com‐
pletion.
! tags...
A string starting with an exclamation mark speci‐
fies 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 nor‐
mal 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 comple‐
tion functions starting with an underscore the first time
completion is tried:
zstyle ':completion:*:*:-command-:*' tag-order \
'functions:-non-comp *' functions
zstyle ':completion:*:functions-non-comp' ignored-patterns '_*'
On the first attempt, all tags will be offered but the
functions tag will be replaced by functions-non-comp.
The ignored-patterns style is set for this tag to exclude
functions starting with an underscore. If there are no
matches, the second value of the tag-order style is used
which completes functions using the default tag, this
time presumably including all function names.
The matches for one tag can be split into different
groups. For example:
zstyle ':completion:*' tag-order \
'options:-long:long\ options
options:-short:short\ options
options:-single-letter:single\ letter\ options'
zstyle ':completion:*:options-long' ignored-patterns '[-+](|-|[^-]*)'
zstyle ':completion:*:options-short' ignored-patterns '--*' '[-+]?'
zstyle ':completion:*:options-single-letter' ignored-patterns '???*'
With the group-names style set, options beginning with
`--', options beginning with a single `-' or `+' but con‐
taining multiple characters, and single-letter options
will be displayed in separate groups with different
descriptions.
Another use of patterns is to try multiple match specifi‐
cations 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 com‐
mands 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-insensi‐
tive matching, restricting the effect to arguments of the
command foo:
zstyle ':completion:*:*:foo:*' tag-order '*' '*:-case'
zstyle ':completion:*-case' matcher 'm:{a-z}={A-Z}'
First, all the tags offered when completing after foo are
tried using the normal tag name. If that generates no
matches, the second value of tag-order is used, which
tries all tags again except that this time each has -case
appended to its name for lookup of styles. Hence this
time the value for the matcher style from the second call
to zstyle in the example is used to make completion
case-insensitive.
It is possible to use the -e option of the zstyle builtin
command to specify conditions for the use of particular
tags. For example:
zstyle -e '*:-command-:*' tag-order '
if [[ -n $PREFIX$SUFFIX ]]; then
reply=( )
else
reply=( - )
fi'
Completion in command position will be attempted only if
the string typed so far is not empty. This is tested
using the PREFIX special parameter; see zshcompwid for a
description of parameters which are special inside com‐
pletion widgets. Setting reply to an empty array pro‐
vides 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 func‐
tion will be used to provide a sensible default behavior
that causes arguments (whether normal command arguments
or arguments of options) to be completed before option
names for most commands.
urls This is used together with the 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 direc‐
tory, the directory hierarchy rooted at this directory
gives the completions. The top level directory should be
the file access method, such as `http', `ftp', `bookmark'
and so on. In many cases the next level of directories
will be a filename. The directory hierarchy can descend
as deep as necessary.
For example,
zstyle ':completion:*' urls ~/.urls
mkdir -p ~/.urls/ftp/ftp.zsh.org/pub/development
allows completion of all the components of the URL
ftp://ftp.zsh.org/pub/development after suitable commands
such as `netscape' or `lynx'. Note, however, that access
methods and files are completed separately, so if the
hosts style is set hosts can be completed without refer‐
ence to the urls style.
See the description in the function _urls itself for more
information (e.g. `more $^fpath/_urls(N)').
use-cache
If this is set, the completion caching layer is activated
for any completions which use it (via the _store_cache,
_retrieve_cache, and _cache_invalid functions). The
directory containing the cache files can be changed with
the cache-path style.
use-compctl
If this style is set to a string not equal to false, 0,
no, and off, the completion system may use any completion
specifications defined with the compctl builtin command.
If the style is unset, this is done only if the zsh/com‐
pctl module is loaded. The string may also contain the
substring `first' to use completions defined with `com‐
pctl -T', and the substring `default' to use the comple‐
tion defined with `compctl -D'.
Note that this is only intended to smooth the transition
from compctl to the new completion system and may disap‐
pear 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 ver‐
sion will be tried if foo only uses default completion.
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 comple‐
tion attempt).
use-perl
Various parts of the function system use awk to extract
words from files or command output as this universally
available. However, many versions of awk have arbitrary
limits on the size of input. If this style is set, perl
will be used instead. This is almost always preferable
if perl is available on your system.
Currently this is only used in completions for `make',
but it may be extended depending on authorial frustra‐
tion.
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 com‐
pleted; this is because on some systems querying all
users can take a prohibitive amount of time.
users-hosts
The values of this style should be of the form
`user@host' or `user:host'. It is used for commands that
need pairs of user- and hostnames. These commands will
complete usernames from this style (only), and will
restrict subsequent hostname completion to hosts paired
with that user in one of the values of the style.
It is possible to group values for sets of commands which
allow a remote login, such as rlogin and ssh, by using
the my-accounts tag. Similarly, values for sets of com‐
mands which usually refer to the accounts of other peo‐
ple, such as talk and finger, can be grouped by using the
other-accounts tag. More ambivalent commands may use the
accounts tag.
users-hosts-ports
Like users-hosts but used for commands like telnet and
containing strings of the form `user@host:port'.
verbose
If set, as it is by default, the completion listing is
more verbose. In particular many commands show descrip‐
tions for options if this style is `true'.
word This is used by the _list completer, which prevents the
insertion of completions until a second completion
attempt when the line has not changed. The normal way of
finding out if the line has changed is to compare its
entire contents between the two 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.
CONTROL FUNCTIONS
The initialization script compinit redefines all the widgets which per‐
form completion to call the supplied widget function _main_complete.
This function acts as a wrapper calling the so-called `completer' func‐
tions that generate matches. If _main_complete is called with argu‐
ments, 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 com‐
pletion and correction if that doesn't generate any matches:
zstyle ':completion:*' completer _complete _correct
after calling compinit. The default value for this style is `_complete
_ignored', i.e. 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 func‐
tions 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 argu‐
ments 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 gener‐
ate 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:...'.
_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:
zle -C all-matches complete-word _generic
bindkey '^Xa' all-matches
zstyle ':completion:all-matches:*' old-matches only
zstyle ':completion:all-matches::::' completer _all_matches
Note that this does not generate completions by itself: first
use any of the standard ways of generating a list of comple‐
tions, then use ^Xa to show all matches. It is possible instead
to add a standard completer to the list and request that the
list of all matches should be directly inserted:
zstyle ':completion:all-matches::::' completer _all_matches _complete
zstyle ':completion:all-matches:*' insert true
In this case the old-matches style should not be set.
_approximate
This is similar to the basic _complete completer but allows the
completions to undergo corrections. The maximum number of
errors can be specified by the max-errors style; see the
description of approximate matching in zshexpn(1) for how errors
are counted. Normally this completer will only be tried after
the normal _complete completer:
zstyle ':completion:*' completer _complete _approximate
This will give correcting completion if and only if normal com‐
pletion yields no possible completions. When corrected comple‐
tions are found, the completer will normally start menu comple‐
tion allowing you to cycle through these strings.
This completer uses the tags corrections and original when gen‐
erating 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 com‐
pletion 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.:
zstyle -e ':completion:*' completer '
if [[ $_last_try != "$HISTNO$BUFFER$CURSOR" ]]; then
_last_try="$HISTNO$BUFFER$CURSOR"
reply=(_complete _match _prefix)
else
reply=(_ignored _correct _approximate)
fi'
This uses the HISTNO parameter and the BUFFER and CURSOR special
parameters that are available inside zle and completion widgets
to find out if the command line hasn't changed since the last
time completion was tried. Only then are the _ignored, _correct
and _approximate completers called.
_complete
This completer generates all possible completions in a con‐
text-sensitive manner, i.e. using the settings defined with the
compdef function explained above and the current settings of all
special parameters. This gives the normal completion behaviour.
To complete arguments of commands, _complete uses the utility
function _normal, which is in turn responsible for finding the
particular function; it is described below. Various contexts of
the form -context- are handled specifically. These are all men‐
tioned above as possible arguments to the #compdef tag.
Before trying to find a function for a specific context, _com‐
plete 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 func‐
tion 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.
_correct
Generate corrections, but not completions, for the current word;
this is similar to _approximate but will not allow any number of
extra characters at the cursor as that completer does. The
effect is similar to spell-checking. It is based on _approxi‐
mate, but the completer field in the context name is correct.
For example, with:
zstyle ':completion:::::' completer _complete _correct _approximate
zstyle ':completion:*:correct:::' max-errors 2 not-numeric
zstyle ':completion:*:approximate:::' max-errors 3 numeric
correction will accept up to two errors. If a numeric argument
is given, correction will not be performed, but correcting com‐
pletion 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 gener‐
ated by the _correct completer -- and probably more.
_expand
This completer function does not really perform completion, but
instead checks if the word on the command line is eligible for
expansion and, if it is, gives detailed 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 con‐
tain 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 substi‐
tute, 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 substi‐
tute, -g for glob and -o for subst-globs-only.
_expand_alias
If the word the cursor is on is an alias, it is expanded and no
other completers are called. The types of aliases which are to
be expanded can be controlled with the styles regular, global
and disabled.
This function is also a bindable command, see the section `Bind‐
able Commands' below.
_history
Complete words from the shell's command history. This com‐
pleter can be controlled by the remove-all-dups, and sort styles
as for the _history_complete_word bindable command, see the sec‐
tion `Bindable Commands' below and the section `Completion Sys‐
tem Configuration' above.
_ignored
The ignored-patterns style can be set to a list of patterns
which are compared against possible completions; matching ones
are removed. With this completer those matches can be rein‐
stated, 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 com‐
pleter. The single-ignored style is also available as described
above.
_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 the section `Completion System Configuration'
above.
_match This completer is intended to be used after the _complete com‐
pleter. 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.
_menu This completer was written as simple example function to show
how menu completion can be enabled in shell code. However, it
has the notable effect of disabling menu 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.
_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 sepa‐
rately-bound completion command). It allows the ordinary com‐
pletion keys to continue to use the list of completions thus
generated, instead of producing a new list of ordinary contex‐
tual completions. It should appear in the list of completers
before any of the widgets which generate matches. It uses two
styles: old-list and old-menu, see the section `Completion Sys‐
tem Configuration' above.
_prefix
This completer can be used to try completion with the suffix
(everything after the cursor) ignored. In other words, the suf‐
fix 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 com‐
pleters only those completers not already tried by the last
invocation of _prefix will be called.
For example, consider this global completer style:
zstyle ':completion:*' completer \
_complete _prefix _correct _prefix:foo
Here, the _prefix completer tries normal completion but ignoring
the suffix. If that doesn't generate any matches, and neither
does the call to the _correct completer 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:
zstyle ':completion:*' completer _complete ... _prefix
zstyle ':completion::prefix:*' completer _complete
The add-space style is also respected. If it is set to `true'
then _prefix will 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.
bashcompinit
This function provides compatibility with bash's programmable
completion system. When run it will define the functions, comp‐
gen and complete which correspond to the bash builtins with the
same names. It will then be possible to use completion specifi‐
cations and functions written for bash.
BINDABLE COMMANDS
In addition to the context-dependent completions provided, which are
expected to work in an intuitively obvious way, there are a few widgets
implementing special behaviour which can be bound separately to keys.
The following is a list of these and their default bindings.
_bash_completions
This function is used by two widgets, _bash_complete-word and
_bash_list-choices. It exists to provide compatibility with
completion bindings in bash. The last character of the binding
determines what is completed: `!', command names; `$', environ‐
ment 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:
for key in '!' '$' '@' '/' '~'; do
bindkey "\e$key" _bash_complete-word
bindkey "^X$key" _bash_list-choices
done
This includes the bindings for `~' in case they were already
bound to something else; the completion code does not override
user bindings.
_correct_filename (^XC)
Correct the filename path at the cursor position. Allows up to
six errors in the name. Can also be called with an argument to
correct a filename path, independently of zle; the correction is
printed on standard output.
_correct_word (^Xc)
Performs correction of the current argument using the usual con‐
textual completions as possible choices. This stores the string
`correct-word' in the function field of the context name and
then calls the _correct completer.
_expand_alias (^Xa)
This function can be used as a completer and as a bindable com‐
mand. 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.
_expand_word (^Xe)
Performs expansion on the current word: equivalent to the stan‐
dard expand-word command, but using the _expand completer.
Before calling it, the function field of the context is set to
`expand-word'.
_generic
This function is not defined as a widget and not bound by
default. However, it can be used to define a widget and will
then store the name of the widget in the function field of the
context and call the completion system. This allows custom com‐
pletion widgets with their own set of style settings to be
defined easily. For example, to define a widget that performs
normal completion and starts menu selection:
zle -C foo complete-word _generic
bindkey '...' foo
zstyle ':completion:foo:*' menu yes select=1
Note in particular that the completer style may be set for the
context in order to change the set of functions used to generate
possible matches. If _generic is called with arguments, those
are passed through to _main_complete as the list of completers
in place of those defined by the completer style.
_history_complete_word (\e/)
Complete words from the shell's command history. This uses the
list, remove-all-dups, sort, and stop styles.
_most_recent_file (^Xm)
Complete the name of the most recently modified file matching
the pattern on the command line (which may be blank). If given
a numeric argument N, complete the Nth most recently modified
file. Note the completion, if any, is always unique.
_next_tags (^Xn)
This command alters the set of matches used to that for the next
tag, or set of tags, either as given by the tag-order style or
as set by default; these matches would otherwise not be avail‐
able. Successive invocations of the command cycle through all
possible sets of tags.
_read_comp (^X^R)
Prompt the user for a string, and use that to perform completion
on the current word. There are two possibilities for the
string. First, it can be a set of words beginning `_', for
example `_files -/', in which case the function with any argu‐
ments will be called to generate the completions. Unambiguous
parts of the function name will be completed automatically (nor‐
mal 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 argu‐
ment.
_complete_debug (^X?)
This widget performs ordinary completion, but captures in a tem‐
porary file a trace of the shell commands executed by the com‐
pletion system. Each completion attempt gets its own file. A
command to view each of these files is pushed onto the editor
buffer stack.
_complete_help (^Xh)
This widget displays information about the context names, the
tags, and the completion functions used when completing at the
current cursor position. If given a numeric 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 func‐
tions called, which in turn is determined by the user's own
styles and other settings.
_complete_help_generic
Unlike other commands listed here, this must be created as a
normal ZLE widget rather than a completion widget (i.e. with zle
-N). It is used for generating help with a widget bound to the
_generic widget that is described above.
If this widget is created using the name of the function, as it
is by default, then when executed it will read a key sequence.
This is expected to be bound to a call to a completion function
that uses the _generic widget. That widget will be executed,
and information provided in the same format that the _com‐
plete_help widget displays for contextual completion.
If the widget's name contains debug, for example if it is cre‐
ated 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 _com‐
plete_debug for contextual completion.
If the widget's name contains noread, it will not read a
keystring but instead arrange that the next use of a generic
widget run in the same shell will have the effect as described
above.
The widget works by setting the shell parameter
ZSH_TRACE_GENERIC_WIDGET which is read by _generic. Unsetting
the parameter cancels any pending effect of the noread form.
For example, after executing the following:
zle -N _complete_debug_generic _complete_help_generic
bindkey '^x:' _complete_debug_generic
typing `C-x :' followed by the key sequence for a generic widget
will cause trace output for that widget to be saved to a file.
_complete_tag (^Xt)
This widget completes symbol tags created by the etags or ctags
programmes (note there is no connection with the completion sys‐
tem'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 $TAGS‐
FILE or $tagsfile respectively. The corresponding completion
tags used are etags and vtags, after emacs and vi respectively.
UTILITY FUNCTIONS
Descriptions follow for utility functions that may be useful when writ‐
ing completion functions. If functions are installed in subdirecto‐
ries, most of these reside in the Base subdirectory. Like the example
functions for commands in the distribution, the utility functions gen‐
erating matches all follow the convention of returning status zero if
they generated completions and non-zero if no matching completions
could be added.
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 rein‐
serts itself into the array.
_all_labels [ -x ] [ -12VJ ] tag name descr [ command args ... ]
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 automat‐
ically be inserted into the args passed to the command. Nor‐
mally, they are put directly after the command, but if one of
the args 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:
local expl
...
if _requested foo; then
...
_all_labels foo expl '...' compadd ... - $matches
fi
Will complete the strings from the matches parameter, using com‐
padd with additional options which will take precedence over
those generated by _all_labels.
_alternative [ -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 specs which are of the form:
`tag:descr:action'. The tags are offered using _tags and if the
tag is requested, the action is executed with the given descrip‐
tion descr. The actions are those accepted by the _arguments
function (described below), excluding the `->state' and `=...'
forms.
For example, the action may be a simple function call:
_alternative \
'users:user:_users' \
'hosts:host:_hosts'
offers usernames and hostnames as possible matches, generated by
the _users and _hosts functions respectively.
Like _arguments, this functions uses _all_labels to execute the
actions, which will loop over all sets of tags. Special han‐
dling is only required if there is an additional valid tag, for
example inside a function called from _alternative.
Like _tags this function supports the -C option to give a dif‐
ferent name for the argument context field.
_arguments [ -nswWACRS ] [ -O name ] [ -M matchspec ] [ : ] spec ...
This function can be used to give a complete specification for
completion for a command whose arguments follow standard UNIX
option and argument conventions. The following forms specify
individual sets of options and arguments; to avoid ambiguity,
these may be separated from the options to _arguments itself by
a single colon. Options to _arguments itself must be in sepa‐
rate words, i.e. -s -w, not -sw.
With the option -n, _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.
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 unneces‐
sary.
*:message:action
*::message:action
*:::message:action
This describes how arguments (usually non-option argu‐
ments, those not beginning with - or +) are to be com‐
pleted 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 mes‐
sage they are modified to refer only to the normal argu‐
ments 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.
By default, options are multi-character name, one `-word'
per option. With -s, options may be single characters,
with more than one option per word, although words start‐
ing with two hyphens, such as `--prefix', are still con‐
sidered complete option names. This is suitable for
standard GNU options.
The combination of -s with -w allows single-letter
options to be combined in a single word even if one or
more of the options take arguments. For example, if -a
takes an argument, with no -s `-ab' is considered as a
single (unhandled) option; with -s -ab is an option with
the argument `b'; with both -s and -w, -ab may be the
option -a and the option -b with arguments still to come.
The option -W takes this 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.
The following forms are available for the initial opt‐
spec, 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 com‐
pleted option and argument will look like
`-fooarg'.
-optname+
The first argument may appear immediately after
optname in the same word, or may appear as a sepa‐
rate word after the option. For example,
`-foo+:...' specifies that the completed option
and argument will look like either `-fooarg' or
`-foo arg'.
-optname=
The argument may appear as the next word, or in
same word as the option name provided that it is
separated from it by an equals sign, for 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 argu‐
ment is mandatory, and in the second form it is optional.
This group may be repeated for options which take multi‐
ple arguments. In other words, :message1:action1:mes‐
sage2:action2 specifies that the option takes two argu‐
ments.
:*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 com‐
pleted 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 com‐
mand 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 var‐
ious other items that should not be applied when the current specifica‐
tion is matched: a single star (*) for the rest arguments (i.e. a spec‐
ification of the form `*:...'); a colon (:) for all normal
(non-option-) arguments; and a hyphen (-) for all options. For exam‐
ple, if `(*)' appears before an option and the option appears on the
command line, the list of remaining arguments (those shown in the above
table beginning with `*:') will not be completed.
To aid in reuse of specifications, it is possible to precede any of the
forms above with `!'; then the form will no longer be completed,
although if the option or 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'.
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 forms for action are as follows.
(single unquoted space)
This is useful where an argument is required but it is not pos‐
sible 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:
:foo:(foo bar baz)
((item1\:desc1 ...))
Similar to the above, but with descriptions for each possible
match. Note the backslash before the colon. For example,
:foo:((a\:bar b\:baz))
The matches will be listed together with their descriptions if
the description style is set with the values tag in the context.
->string
In this form, _arguments processes the arguments and options and
then returns control to the calling function with parameters set
to indicate the state of processing; the calling function then
makes its own arrangements for generating completions. For
example, functions that implement a state machine can use this
type of action.
Where _arguments encounters a `->string', it will strip all
leading and trailing whitespace from string and set the array
state to the set of all stringss for which an action is to be
performed.
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 indi‐
cate that $state is to be handled.
In addition to $state, _arguments also sets the global parame‐
ters `context', `line' and `opt_args' as described below, and
does not reset any changes made to the special parameters such
as PREFIX and words. This gives the calling function the choice
of resetting these parameters or propagating changes in them.
A function calling _arguments with at least one action contain‐
ing a `->string' therefore must declare appropriate local param‐
eters:
local context state line
typeset -A opt_args
to avoid _arguments from altering the global environment.
{eval-string}
A string in braces is evaluated as shell code to generate
matches. If the eval-string itself does not begin with an open‐
ing 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 spe‐
cial 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 argu‐
ments, 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 command name and normal arguments from the command line, i.e. the
words from the command line excluding all options and their arguments.
Options are stored in the associative array `opt_args' with option
names as keys and their arguments as the values. For options that have
more than one argument these are given as one string, separated by
colons. All colons in the original arguments are preceded with back‐
slashes.
The parameter `context' is set when returning to the calling function
to perform an action of the form `->string'. It is set to an array of
elements corresponding to the elements of $state. Each element is a
suitable name for the argument field of the context: either a string of
the form `option-opt-n' for the n'th argument of the 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 posi‐
tion, n is the string `rest'. For example, when completing the argu‐
ment 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.
It is possible to specify multiple sets of options and arguments with
the sets separated by single hyphens. The specifications before the
first hyphen (if any) are shared by all the remaining sets. The first
word in every other set provides a name for the set which may appear in
exclusion lists in specifications, either alone or before one of the
possible values described above. In the second case a `-' should
appear between this name and the remainder.
For example:
_arguments \
-a \
- set1 \
-c \
- set2 \
-d \
':arg:(x2 y2)'
This defines two sets. When the command line contains the option `-c',
the `-d' option and the argument will not be considered possible com‐
pletions. When it contains `-d' or an argument, the option `-c' will
not be considered. However, after `-a' both sets will still be consid‐
ered valid.
If the name given for one of the mutually exclusive sets is of the form
`(name)' then only one value from each set will ever be completed; more
formally, all specifications are mutually exclusive to all other speci‐
fications in the same set. This is useful for defining multiple sets
of options which are mutually exclusive and in which the options are
aliases for each other. For example:
_arguments \
-a -b \
- '(compress)' \
{-c,--compress}'[compress]' \
- '(uncompress)' \
{-d,--decompress}'[decompress]'
As the completion code has to parse the command line separately for
each set this form of argument is slow and 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.
The options -S and -A are available to simplify the specifications for
commands with standard option parsing. With -S, no option will be com‐
pleted after a `--' appearing on its own on the line; this argument
will otherwise be ignored; hence in the line
foobar -a -- -b
the `-a' is considered an option but the `-b' is considered an argu‐
ment, while the `--' is considered to be neither.
With -A, no options will be completed after the first non-option argu‐
ment on the line. The -A must be followed by 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 optspecs, the form is `-A "-*"'.
The option `-O name' specifies the name of an array whose elements will
be passed as arguments to functions called to execute actions. For
example, this can be used to pass the same set of options for the com‐
padd builtin to all actions.
The option `-M spec' sets a match specification to use to completion
option names and values. It must appear before the first argument
specification. The default is `r:|[_-]=* r:|=*': this allows partial
word completion after `_' and `-', for example `-f-b' can be completed
to `-foo-bar'.
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:
local curcontext="$curcontext"
This is useful where it is not possible for multiple states to be valid
together.
The option `--' allows _arguments to work out the names of long options
that support the `--help' option which is standard in many GNU com‐
mands. 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 specifiers of the form `pattern:message:action';
note that normal _arguments specifiers are not used. The pattern is
matched against the help text for an option, and if it matches the mes‐
sage and action are used as for other argument specifiers. For exam‐
ple:
_arguments -- '*\*:toggle:(yes no)' \
'*=FILE*:file:_files' \
'*=DIR*:directory:_files -/' \
'*=PATH*:directory:_files -/'
Here, `yes' and `no' will be completed as the argument of options whose
description ends in a star; file names will be completed for options
that contain the substring `=FILE' in the description; and directories
will be completed for options whose 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:
-C, --directory=DIR change to directory DIR
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 argu‐
ment for an option is optional. This can be specified explicitly by
doubling the colon before the message.
If the pattern ends in `(-)', this will 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 `=-'.
The `_arguments --' can be followed by the option `-i patterns' to give
patterns for options which are not to be completed. The patterns can
be given as the name of an array parameter or as a literal list in
parentheses. For example,
_arguments -- -i \
"(--(en|dis)able-FEATURE*)"
will cause completion to ignore the options `--enable-FEATURE' and
`--disable-FEATURE' (this example is useful with GNU configure).
The `_arguments --' form can also be followed by the option `-s pair'
to describe option aliases. Each pair consists of a pattern and a
replacement. For example, some configure-scripts describe options only
as `--enable-foo', but also accept `--disable-foo'. To allow comple‐
tion of the second form:
_arguments -- -s "(#--enable- --disable-)"
Here is a more general example of the use of _arguments:
_arguments '-l+:left border:' \
'-format:paper size:(letter A4)' \
'*-copy:output file:_files::resolution:(300 600)' \
':postscript file:_files -g \*.\(ps\|eps\)' \
'*:page number:'
This describes three options: `-l', `-format', and `-copy'. The first
takes one 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 com‐
pleted.
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 numbers' but does not offer
completions.
_cache_invalid cache_identifier
This function returns status zero if the completions cache cor‐
responding to the given cache identifier needs rebuilding. It
determines this by looking up the cache-policy style for the
current context. This should provide a function name which is
run with the full path to the relevant cache file as the only
argument.
Example:
_example_caching_policy () {
# rebuild if cache is more than a week old
oldp=( "$1"(Nmw+1) )
(( $#oldp ))
}
_call_function return name [ args ... ]
If a function name exists, it is called with the arguments args.
The return argument gives the name of a parameter in which the
return status from the function name; if return is empty or a
single hyphen it is ignored.
The return status of _call_function itself is zero if the func‐
tion name exists and was called and non-zero otherwise.
_call_program tag string ...
This function provides a mechanism for the user to override the
use of an external command. It looks up the command style with
the supplied tag. If the style is set, its value is used as the
command to execute. The strings from the call to _call_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.
_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 fields for which the value is known).
The matches generated will be taken from the value of the style.
These should contain the possible values for the combinations in
the appropriate order (users, hosts, ports in the example
above). The different fields 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' specifi‐
cation 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 exam‐
ple, if there is no `users-hosts-ports' or no matching hostname
when a host is required, the function `_hosts' will automati‐
cally 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 com‐
padd when generating matches from the style value, or to the
functions for the fields if they are called.
_describe [ -oO | -t tag ] descr name1 [ name2 ] opts ... -- ...
This function associates completions with descriptions. Multi‐
ple groups separated by -- can be supplied, potentially with
different completion options opts.
The descr is taken as a string to display above the matches if
the format style for the descriptions tag is set. This is fol‐
lowed by one or two names of arrays followed by options to pass
to compadd. The first array contains the possible completions
with their descriptions in the form `completion:description'.
If a second array is given, it should have the same number of
elements as the first; in this case the corresponding elements
are added as possible completions instead of the completion
strings from the first array. The completion list will retain
the descriptions from the first array. Finally, a set of com‐
pletion 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-hid‐
den, 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 `val‐
ues' or, if the -o option is given, `options'.
If selected by the list-grouped style, strings with the same
description will appear together in the list.
_describe uses the _all_labels function to generate the matches,
so it does not need to appear inside a loop over tag labels.
_description [ -x ] [ -12VJ ] tag name descr [ spec ... ]
This function is not to be confused with the previous one; it is
used as a helper function for creating options to compadd. It
is buried inside many of the higher level completion functions
and so often does not need to be called directly.
The styles listed below are tested in the current context using
the given tag. The resulting options for compadd are put into
the array named name (this is traditionally `expl', but this
convention is not enforced). The description for the corre‐
sponding set of matches is passed to the function in descr.
The styles tested are: format, hidden, matcher, ignored-patterns
and group-name. 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 modi‐
fied so that the sequence `%d' is replaced by the descr given as
the third argument without any leading or trailing white space.
If, after removing the white space, the descr is the empty
string, the format style will not be used and the options put
into the name array will not contain an explanation string to be
displayed above the matches.
If _description is called with more than three arguments, the
additional specs should be of the form `char:str'. These supply
escape sequence replacements for the format style: every appear‐
ance of `%char' will be replaced by string.
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:
local expl
_description files expl file
compadd "$expl[@]" - "$files[@]"
Note the use of the parameter expl, the hyphen, and the list of
matches. Almost all calls to compadd within the completion sys‐
tem use a similar format; this ensures that user-specified
styles are correctly passed down to the builtins which implement
the internals of completion.
_dispatch context string ...
This sets the current context to context and looks for comple‐
tion functions to handle this context by hunting through the
list of command names or special contexts (as described above
for compdef) given as string .... 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 fall‐
back.
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 argu‐
ment.
_files The function _files calls _path_files with all the arguments it
was passed except for -g and -/. The use of these two options
depends on the setting of the file-patterns style.
This function accepts the full set of options allowed by
_path_files, described below.
_gnu_generic
This function is a simple wrapper around the _arguments function
described above. It can be used to determine automatically the
long options understood by commands that produce a list when
passed the option `--help'. It is intended to be used as a
top-level completion function in its own right. For example, to
enable option completion for the commands foo and bar, use
compdef _gnu_generic foo bar
after the call to compinit.
The completion system as supplied is conservative in its use of
this function, since it is important to be sure the command
understands the option `--help'.
_guard [ options ] pattern descr
This function is intended to be used in the action for the spec‐
ifications passed to _arguments and similar functions. It
returns immediately with a non-zero return status if the string
to be completed does not match the pattern. If the pattern
matches, the descr is displayed; the function then returns sta‐
tus zero if the word to complete is not empty, non-zero other‐
wise.
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:
_arguments '-n-: :_guard "[0-9]#" "numeric value"' '-none'
_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 fol‐
lowed by another character, only options are completed.
_message [ -r12 ] [ -VJ group ] descr
_message -e [ tag ] descr
The descr is used in the same way as the third argument to the
_description function, except that the resulting string will
always be shown whether or not matches were generated. This is
useful for displaying a help message in places where no comple‐
tions 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.
The -12VJ options and the group are passed to compadd and hence
determine the group the message string is added to.
The second form gives a description for completions with the tag
tag to be shown even if there are no matches for that tag. 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.
_multi_parts 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.
_next_label [ -x ] [ -12VJ ] tag name descr [ options ... ]
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 options given after the descr are set in the parameter given
by name, and hence are to be passed to compadd or whatever func‐
tion 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.
local expl ret=1
...
if _requested foo; then
...
while _next_label foo expl '...'; do
compadd "$expl[@]" ... && ret=0
done
...
fi
return ret
_normal
This is the standard function called to handle completion out‐
side any special -context-. It is called both to complete the
command word and also the arguments for a command. In the sec‐
ond case, _normal looks for a special completion for that com‐
mand, 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 com‐
pletes after pre-command specifiers such as nohup, removes the
first word from the words array, decrements the CURRENT parame‐
ter, then calls _normal again. The effect is that `nohup cmd
...' is treated in the same way as `cmd ...'.
If the command name matches one of the patterns given by one of
the options -p or -P to compdef, the corresponding completion
function is called and then the parameter _compskip is checked.
If it is set completion is terminated at that point even if no
matches have been found. This is the same effect as in the
-first- context.
_options
This can be used to complete the names of shell options. It
provides a matcher 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.
_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_com‐
plete 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.
_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 pat‐
tern is probably necessary.
All other arguments are passed to the compadd builtin.
_path_files
This function is used throughout the completion system to com‐
plete 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 com‐
padd builtin. It gives direct control over which file‐
names 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.
_pick_variant [ -c command ] [ -r name ] label=pattern ... label [ args
... ]
This function is used to resolve situations where a single com‐
mand 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 `com‐
mand args ...' 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 `-r name' is given, the label picked is stored in the
parameter named name.
The results are also cached in the _cmd_variant associative
array indexed by the name of the command run.
_regex_arguments name spec ...
This function generates a completion function name which matches
the specifications spec ..., a set of regular expressions as
described below. After running _regex_arguments, the function
name should be called as a normal completion function. The pat‐
tern to be matched is given by the contents of the words array
up to the current 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 (imply‐
ing the remaining word is the one for which completions are to
be generated). The completion target is restricted to the
remaining word and any actions for the corresponding patterns
are executed. In this case, nothing is stripped from the com‐
mand line string. The order of evaluation of the actions 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)looka‐
head*' matches the command line string. If so, `guard'
is evaluated and its return status is examined to deter‐
mine 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 comple‐
tion target.
/pattern/- [%lookahead%] [-guard] [:tag:descr:action]
This is similar to `/pattern/ ...' but the actions 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 specs; note each paren‐
thesis is a single argument to _regex_arguments.
spec # This allows any number of repetitions of spec.
spec spec
The two specs are to be matched one after the other as
described above.
spec | spec
Either of the two specs can be matched.
The function _regex_words can be used as a helper function to
generate matches for a set of alternative words possibly with
their own arguments as a command line argument.
Examples:
_regex_arguments _tst /$'[^\0]#\0'/ \
/$'[^\0]#\0'/ :'compadd aaa'
This generates a function _tst that completes aaa as its only
argument. The tag and description for the action have been
omitted for brevity (this works but is not recommended in normal
use). The first component matches the command word, which is
arbitrary; the second matches any argument. As the argument is
also arbitrary, any following component would not depend on aaa
being present.
_regex_arguments _tst /$'[^\0]#\0'/ \
/$'aaa\0'/ :'compadd aaa'
This is a more typical use; it is similar, but any following
patterns would only match if aaa was present as the first argu‐
ment.
_regex_arguments _tst /$'[^\0]#\0'/ \( \
/$'aaa\0'/ :'compadd aaa' \
/$'bbb\0'/ :'compadd bbb' \) \#
In this example, an indefinite number of command arguments may
be completed. Odd arguments are completed as aaa and even argu‐
ments as bbb. Completion fails unless the set of aaa and bbb
arguments before the current one is matched correctly.
_regex_arguments _tst /$'[^\0]#\0'/ \
\( /$'aaa\0'/ :'compadd aaa' \| \
/$'bbb\0'/ :'compadd bbb' \) \#
This is similar, but either aaa or bbb may be completed for any
argument. In this case _regex_words could be used to generate a
suitable expression for the arguments.
_regex_words tag description spec ...
This function can be used to generate arguments for the
_regex_arguments command which may be inserted at any point
where a set of rules is expected. The tag and description give
a standard tag and description pertaining to the current con‐
text. 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 equiva‐
lent 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 argu‐
ments may be completed after the abbreviated form.
The second part of spec is a description for the word being com‐
pleted.
The optional third part of the spec describes how words follow‐
ing 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 con‐
taining previously generated regex arguments.
The option -t term specifies a terminator for the word instead
of the usual space. This is handled as an auto-removable suffix
in the manner of the option -s sep to _values.
The result of the processing by _regex_words is placed in the
array reply, which should be made local to the calling function.
If the set of words and arguments may be matched repeatedly, a #
should be appended to the generated array at that point.
For example:
local -a reply
_regex_words mydb-commands 'mydb commands' \
'add:add an entry to mydb:$mydb_add_cmds' \
'show:show entries in mydb'
_regex_arguments _mydb "$reply[@]"
_mydb "$@"
This shows a completion function for a command mydb which takes
two command arguments, add and show. show takes no arguments,
while the arguments for add have already been prepared in an
array mydb_add_cmds, quite possibly by a previous call to
_regex_words.
_requested [ -x ] [ -12VJ ] tag [ name descr [ command args ... ] ]
This function is called to decide whether a tag already regis‐
tered 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 other‐
wise. The function is typically used as part of a loop over
different tags as follows:
_tags foo bar baz
while _tags; do
if _requested foo; then
... # perform completion for foo
fi
... # test the tags bar and baz in the same way
... # exit loop if matches were generated
done
Note that the test for whether matches were generated is not
performed until the end of the _tags loop. This is so that the
user can set the tag-order style to specify a set of tags to be
completed at the same time.
If name and descr are given, _requested calls the _description
function with these 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:
local expl ret=1
_tags foo bar baz
while _tags; do
_requested foo expl 'description' \
compadd foobar foobaz && ret=0
...
(( ret )) || break
done
If the command is not compadd, it must nevertheless be prepared
to handle the same options.
_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.
_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.
_setup tag [ group ]
This function sets up the special parameters used by the comple‐
tion system appropriately for the tag given as the first argu‐
ment. It uses the styles list-colors, list-packed,
list-rows-first, last-prompt, accept-exact, menu and force-list.
The optional group supplies the name of the group in which the
matches will be placed. If it is not given, the tag is used as
the group name.
This function is called automatically from _description and
hence is not normally called explicitly.
_store_cache cache_identifier params ...
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 parame‐
ters 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
params arguments are the parameters to dump to the file.
The return status is zero if storage was successful. The func‐
tion 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.
_tags [ [ -C name ] tags ... ]
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, sec‐
ond, 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 argu‐
ment field (the fifth) of the context in the curcontext parame‐
ter 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).
_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 is used as a string to print as a
description before listing the values.
All other arguments describe the possible values and their argu‐
ments 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:
_values -s , 'description' \
'*foo[bar]' \
'(two)*one[number]:first count:' \
'two[another number]::second count:(1 2 3)'
This describes three possible values: `foo', `one', and `two'.
The first is described as `bar', takes no argument and may
appear more than once. The second is described as `number', may
appear more than once, and takes one mandatory argument
described as `first count'; no action is specified, so it will
not be completed. The `(two)' at the beginning says that if the
value `one' is on the line, the value `two' will no longer be
considered a possible completion. Finally, the last value
(`two') is 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 com‐
mas.
Like _arguments, this function temporarily adds another context
name component to the arguments element (the fifth) of the cur‐
rent 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 associa‐
tive array used by _arguments. Hence the function calling _val‐
ues should declare the local parameters state, line, context and
val_args:
local context state line
typeset -A val_args
when using an action of the form `->string'. With this function
the context parameter will be set to the name of the value whose
argument is to be completed.
Note 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 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).
_wanted [ -x ] [ -C name ] [ -12VJ ] tag name descr command args ...
In many contexts, completion can only generate one particular
set of matches, usually corresponding to a single tag. However,
it is still necessary to decide whether the user requires
matches of this type. This function is useful in such a case.
The arguments to _wanted are the same as those to _requested,
i.e. arguments to be passed to _description. However, in this
case the command is not optional; all the processing of tags,
including the loop over both tags and tag labels and the genera‐
tion of matches, is carried out automatically by _wanted.
Hence to offer only one tag and immediately add the correspond‐
ing matches with the given description:
local expl
_wanted tag expl 'description' \
compadd matches...
Note that, as for _requested, the command must be able to accept
options to be passed down to compadd.
Like _tags this function supports the -C option to give a dif‐
ferent name for the argument context field. The -x option has
the same meaning as for _description.
COMPLETION DIRECTORIES
In the source distribution, the files are contained in various subdi‐
rectories of the Completion directory. They may have been installed in
the same structure, or into one single function directory. The follow‐
ing 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 docu‐
mented 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 ver‐
sion 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.
zsh 4.3.6 April 2, 2008 ZSHCOMPSYS(1)
