20.3 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.

20.3.1 Overview

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

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

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

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

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

The 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 Bindable Commands.

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

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

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 pattern as ‘*’ in case the style has some meaning outside the completion system.

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

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

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 Completion Widgets)). For example,

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

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

Note that the order in which styles are defined does not matter; the style mechanism uses the most specific possible match for a particular style to determine the set of values. Strings are preferred over patterns (for example, ‘:completion::complete:::foo’ is more specific than ‘:completion::complete:::*'), and longer patterns are preferred over the pattern ‘*’. See The zsh/zutil Module for details.

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

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

20.3.2 Standard Tags

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

accounts

used to look up the users-hosts style

all-expansions

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

all-files

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

arguments

for arguments to a command

arrays

for names of array parameters

association-keys

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

bookmarks

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

builtins

for names of builtin commands

characters

for single characters in arguments of commands such as stty. Also used when 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 — local-directories is used instead when completing arguments of cd and related builtin commands when the cdpath array is set

directory-stack

for entries in the directory stack

displays

for X display names

domains

for network domains

email-plugin

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

expansions

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

extensions

for X server extensions

file-descriptors

for numbers of open file descriptors

files

the generic file-matching tag used by functions completing filenames

fonts

for X font names

fstypes

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

functions

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

globbed-files

for filenames when the name has been generated by pattern matching

groups

for names of user groups

history-words

for words from the history

hosts

for hostnames

indexes

for array indexes

interfaces

for network interfaces

jobs

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

keymaps

for names of zsh keymaps

keysyms

for names of X keysyms

libraries

for names of system libraries

limits

for system limits

local-directories

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

mailboxes

for e-mail folders

manuals

for names of manual pages

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 special-dirs styles

pods

for perl pods (documentation files)

ports

for communication ports

prefixes

for prefixes (like those of a URL)

printers

for print queue names

processes

for process identifiers

processes-names

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

sequences

for sequences (e.g. mh sequences)

sessions

for sessions in the zftp function suite

signals

for signal names

strings

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

styles

for styles used by the zstyle builtin command

suffixes

for filename extensions

tags

for tags (e.g. rpm tags)

targets

for makefile targets

time-zones

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

types

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

urls

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

users

for usernames

values

for one of a set of values in certain lists

variant

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

visuals

for X visuals

warnings

used to look up the format style for warnings

widgets

for zsh widget names

windows

for IDs of X windows

zsh-options

for shell options

20.3.3 Standard Styles

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

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

zstyle ':completion:*:default' menu ...
accept-exact

This is tested for the default tag in addition to the tags valid for the current context. If it is set to ‘true’ and any of the trial matches is the same as the string on the command line, this match will immediately be accepted (even if it would otherwise be considered ambiguous).

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

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

accept-exact-dirs

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

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

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

If you wish to inhibit this behaviour entirely, set the path-completion style (see below) to ‘false’.

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. Depending on personal preferences, it may be useful to set this style to something like ‘specify: %d’. Note that this may not work for some commands.

avoid-completer

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

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

cache-path

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

cache-policy

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

call-command

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

command

In many places, completion functions need to call external commands to generate the list of completions. This style can be used to override the command that is called in some such cases. The elements of the value are joined with spaces to form a command line to execute. The value can also start with a hyphen, in which case the usual 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 complete. The default for this style is the value of the special parameter path.

commands

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

complete

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

complete-options

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

completer

The strings given as the value of this style provide the names of the completer functions to use. The available completer functions are described in Control Functions.

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

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 characters are preferred as the completion system may otherwise become confused. The default list is :, +, /, -, %. The list may be empty to force a delimiter to be typed.

disabled

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

domains

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

environ

The environ style is used when completing for ‘sudo’. It is set to an array of ‘VAR=value’ assignments to be exported into the local environment before the completion for the target command is invoked.

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

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

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

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

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’.

fake

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

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

fake-always

This works identically to the fake style except that the ignored-patterns style is not applied to it. This makes it possible to override a set of matches completely by setting the ignored patterns to ‘*’.

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

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

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

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

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

fake-parameters

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

file-list

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

zmodload -i zsh/stat
disable stat

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

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

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

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

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

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

file-patterns

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

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

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

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

The tag may also be followed by an optional second colon and a description, which will be used for the ‘%d’ in the value of the format style (if that is set) instead of the default description supplied by the completion function. The inclusion of a description also gives precedence to associated options such as for completion grouping so it can be used where files should be separated.

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

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.

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

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

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

file-sort

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

file-split-chars

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

filter

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

force-list

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

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

format

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

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

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

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

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

It is possible to use printf-style field width specifiers with ‘%d’ and similar escape sequences. This is handled by the zformat builtin command from the zsh/zutil module, see The zsh/zutil Module.

gain-privileges

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

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 completer 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 command position the completion system generates names of builtin and external commands, names of aliases, shell functions and parameters and reserved words as possible completions. To have the external commands and shell functions listed separately:

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 {No value for `dsq'}

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

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

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 possible completions at all, the tag-order style can be modified as described below.

hosts

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

hosts-ports

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

ignore-line

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

The values ‘current’ and ‘current-shown’ are a bit like the opposite of the accept-exact style: only strings with missing characters will be completed.

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

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.

ignored-patterns

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

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

insert

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

insert-ids

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

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

insert-sections

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

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

man ssh_<TAB> may be completed to man 5 ssh_config.

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

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

The default for this style is ‘false’.

insert-tab

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

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

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

insert-unambiguous

This is used by the _match and _approximate completers. These completers are often used with menu completion since the word typed may bear little resemblance to the final completion. However, if this style is ‘true’, the completer will start menu completion only if it could find no unambiguous initial string at least as long as the original string typed by the user.

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

In the case of the _match completer, the style may also be set to the string ‘pattern’. Then the pattern on the line is left unchanged if it does not match unambiguously.

keep-prefix

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

The behaviour of _expand when this style is ‘true’ is to cause _expand to give up when a single expansion with the restored prefix is the same as the original; hence any remaining completers may be called.

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.

last-prompt

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

list

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

list-colors

If the zsh/complist module is loaded, this style can be used to set color specifications. This mechanism replaces the use of the ZLS_COLORS and ZLS_COLOURS parameters described in The zsh/complist Module, but the syntax is the same.

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

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

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

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. {No value for `dsq'}).

list-dirs-first

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

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 zsh/complist Module). The value, if not the empty string, will be displayed after every screenful and the shell will prompt for a key press; if the style is set to the empty string, a default prompt will be used.

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

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

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-separator

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

list-suffixes

This style is used by the function that completes filenames. If it is ‘true’, and completion is attempted on a string containing multiple partially typed pathname components, all ambiguous components will be shown. Otherwise, completion stops at the first ambiguous component.

local

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

For example:

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

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

mail-directory

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

match-original

This is used by the _match completer. If it is set to only, _match will try to 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 current context. Its value is placed before any match specifications given by the matcher-list style so can override them via the use of an x: specification. The value should be in the form described in Completion Matching Control. For examples of this, see the description of the tag-order style.

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

matcher-list

This style can be set to a list of match specifications that are to be applied everywhere. Match specifications are described in Completion Matching Control. 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 {No value for `dsq'} 'm:{a-zA-Z}={A-Za-z}'

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

zstyle ':completion:*' matcher-list \ 
       {No value for `dsq'} '+m:{a-z}={A-Z}' '+m:{A-Z}={a-z}'

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

zstyle ':completion:*' completer _complete _prefix
zstyle ':completion:*:complete:*:*:*' matcher-list \ 
       {No value for `dsq'} '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 specification, then normal completion with case-insensitive matching, then correction, and finally partial-word completion:

zstyle ':completion:*' completer \ 
    _complete _correct _complete:foo
zstyle ':completion:*:complete:*:*:*' matcher-list \ 
    {No value for `dsq'} '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 be called once even if the matcher-list contains more than one element.

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

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

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

max-errors

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

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

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

two errors are allowed if no numeric argument is given, but with a numeric argument of six (as in ‘ESC-6 TAB’), up to six errors are accepted. Hence with a value of ‘0 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’ (Typically, the value ‘select=long-list’ described later is more useful as it provides control over scrolling.)

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

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

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

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

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

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

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

Finally, it is possible to activate two special modes of menu selection. The word ‘interactive’ in the value causes interactive mode to be entered immediately when menu selection is started; see The zsh/complist Module 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 listing.

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

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

old-matches

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

If this style is set it is generally unwise to call the _all_matches completer 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.

path-completion

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

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

pine-directory

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

ports

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

prefix-hidden

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

The default value for this style is ‘false’.

prefix-needed

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

The style is applicable to the options, signals, jobs, functions, and parameters completion tags.

For command options, this means that the initial ‘-’, ‘+’, or ‘--’ must be typed explicitly before option names will be completed.

For signals, an initial ‘-’ is required before signal names will be completed.

For jobs, an initial ‘%’ is required before job names will be completed.

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

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

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 _history_complete_word bindable command to decide which words should be completed.

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

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

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

recursive-files

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

For example,

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

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

regular

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

rehash

If this is set when completing external commands, the internal list (hash) of commands will be updated for each search by issuing the rehash command. There is a speed 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 information. This includes the completion for the CVS command.

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

remove-all-dups

The _history_complete_word bindable command and the _history completer use this to 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 single lines.

separate-sections

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

The default for this style is ‘false’.

show-ambiguity

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

show-completer

Tested whenever a new completer is tried. If it is ‘true’, the completion system outputs a progress message in the listing area showing what completer is being tried. The message will be overwritten by any output when completions are found and is removed after completion is finished.

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

This allows the standard ordering of matches to be overridden.

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

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

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

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

special-dirs

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

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

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

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

stop

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

strip-comments

If set to ‘true’, this style causes non-essential comment text to be removed from 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 available in a particular context will be used.

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

For example:

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

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

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

-

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

! tags...

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

tag:label ...

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

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

tag:label:description

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

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

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

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

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

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

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

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

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

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

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

It is possible to use the -e option of the zstyle builtin command to specify 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 Completion Widgets for a description of parameters which are special inside completion widgets. Setting reply to an empty array provides the default behaviour of trying all tags at once; setting it to an array containing only a hyphen disables the use of all tags and hence of all completions.

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

urls

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

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

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

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

For example,

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

allows completion of all the components of the URL ftp://ftp.zsh.org/pub after 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 reference to the urls style.

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

use-cache

If this is set, the completion caching layer is activated for any completions which use it (via the _store_cache, _retrieve_cache, and _cache_invalid functions). The 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/compctl module is loaded. The string may also contain the substring ‘first’ to use completions defined with ‘compctl -T’, and the substring ‘default’ to use the completion defined with ‘compctl -D’.

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

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

use-ip

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

users

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

users-hosts

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

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

users-hosts-ports

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

verbose

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

word

This is used by the _list completer, which prevents the insertion of completions until a second completion attempt when the line has not changed. The normal way of finding out if the line has changed is to compare its entire contents between the two 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.