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zshcompsys(1)

ZSHCOMPSYS(1)               General Commands Manual              ZSHCOMPSYS(1)

NAME
       zshcompsys - zsh completion system

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

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


       •      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 de‐
       scribe.

       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 zshmodules(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  be‐
       low. This dispatcher decides which function should be called to produce
       the completions, and calls it. The result is passed to one or more com‐
       pleters,  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 (`au‐
       toload -U compinstall' is recommended).  You can abort the installation
       any time you are being prompted for information, and your  .zshrc  will
       not  be altered at all; changes only take place right at the end, where
       you are specifically asked for confirmation.

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

       To  initialize  the system, the function compinit should be in a direc‐
       tory mentioned in the fpath parameter, and should be  autoloaded  (`au‐
       toload -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  com‐
       plete-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  al‐
       ready.

       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  en‐
       tirely when the -C option is given, provided the dumpfile exists.

       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 ex‐
       ecuted 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.

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

   Autoloaded files
       The convention for autoloaded functions used in completion is that they
       start with an 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 to the path: this allows the functions to be in  the
       same format as in the zsh source distribution.

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

       The tags are:

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

              Each name may also be of the form `cmd=service'.  When  complet‐
              ing  the  command  cmd, the function typically behaves as if the
              command (or special context) service  was  being  completed  in‐
              stead.   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-sequence ...
              This  option  creates  a widget behaving like the builtin widget
              style and binds it to the  given  key-sequences,  if  any.   The
              style  must  be  one of the builtin widgets that perform 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 it already was (that is, was bound to some‐
              thing other than undefined-key).  The  widget  created  has  the
              same  name  as the file and can be bound to any other keys using
              bindkey as usual.

       #compdef -K widget-name style key-sequence [ name style seq ... ]
              This is similar to -k except that only one key-sequence argument
              may be given for each widget-name style pair.  However, the  en‐
              tire 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 (`name=(...)')

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

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

       -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  de‐
              fined for commands will be.

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

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

       -redirect-
              The word after a redirection operator.

       -subscript-
              The contents of a parameter subscript.

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

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

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

       The contexts -redirect- and -value- allow extra context-specific 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
       `-redirect-,op,command',  where op is the redirection operator and com‐
       mand is the name of the command on the line.  If there is no command on
       the line yet, the command field will be empty.

       For the -value- context, the form is `-value-,name,command', where name
       is the name of the parameter on the left hand side of  the  assignment.
       In  the  case  of  elements  of  an associative array, for example `as‐
       soc=(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 re‐
       placing 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-,-de‐
       fault-', in that order, until it finds a function to  handle  the  con‐
       text.

       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 be‐
       low); 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 di‐
       rectly.

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

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

                     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.  Setting $_compskip in this manner is
              of particular utility when using the -p option, as otherwise the
              dispatcher will move on to additional functions (likely the  de‐
              fault one) after calling the pattern-context one, which can man‐
              gle the display of completion possibilities if not handled prop‐
              erly.

              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, ex‐
              pand-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 al‐
              ready to bound to something other than undefined-key.

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

              Wherever applicable, the -a option makes the function  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 begins building the context.  The context represents every‐
       thing that the shell knows about the meaning of the  command  line  and
       the  significance of the cursor position.  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).

       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 mul‐
       tiple fields separated by colons, referred to simply as  `the  context'
       in the remainder of the documentation.  Note that a user of the comple‐
       tion  system rarely needs to compose a context string, unless for exam‐
       ple 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 gen‐
       erated, similarly to shell options but with much  more  control.   They
       are defined with the zstyle builtin command (see zshmodules(1)).

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

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


       •      The function, if completion is called from a named widget rather
              than  through  the  normal completion system.  Typically this is
              blank, but it is set by special widgets such as  predict-on  and
              the  various  functions in the Widget directory of the 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  be‐
              low.


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

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

       says that normal completion was attempted as the first argument to  the
       option -o of the 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  us‐
       ing  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  de‐
       scribed in the section `Bindable Commands' below.

       When  looking  up styles the completion system uses full context names,
       including the tag.  Looking up the value of a style therefore  consists
       of two things: the context, which is matched to the most specific (best
       fitting)  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  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 in‐
       ternals of completion functions (see see zshcompwid(1))).  For example,

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

       This  forces  the value of the hosts style to be read from the variable
       myhosts each time a host name is needed; this is useful if the value of
       myhosts can change dynamically.  For 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 pat‐
       terns (for example, `:completion::complete:::foo' is more specific than
       `:completion::complete:::*'), and longer patterns  are  preferred  over
       the pattern `*'. See zmodules(1) 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  in‐
       clude  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 com‐
       mand was intended).

       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 -- 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 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

       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 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.

       accept-exact-dirs
              This  is used by filename completion.  Unlike accept-exact it is
              a boolean.  By default, filename completion examines all  compo‐
              nents  of  a path to see if there are completions of that compo‐
              nent, 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  result‐
              ing  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  ex‐
              pansion 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  al‐
              ready 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  de‐
              fined.   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 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  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 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 op‐
              tions.  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 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  de‐
              fault 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 de‐
              fault 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/re‐
              solv.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  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.

       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 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 ig‐
              nored-patterns style is not applied to it.  This makes it possi‐
              ble to override a set of matches completely by setting  the  ig‐
              nored 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 quoted with a backslash to  be  treated  liter‐
              ally.

              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 directo‐
              ries 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 re‐
              place 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  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  to‐
              gether 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.  The  inclusion  of  a  de‐
              scription  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 with‐
              out a tag to determine  in  which  order  the  names  should  be
              listed;  menu completion will cycle through them in the same or‐
              der.  The possible values are: `size' to sort by the size of the
              file; `links' to sort by the number of links to the file; `modi‐
              fication' (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 al‐
              phabetically by name.  If the value  contains  the  string  `re‐
              verse',  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 charac‐
              ters 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_ad‐
              dresses)  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  se‐
              quence  `%d'  in  this  string will be replaced with a short de‐
              scription of what these matches are.  This string may also  con‐
              tain  the  output  attribute  sequences understood by compadd -X
              (see zshcompwid(1)).

              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  re‐
              placed 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).

       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 ap‐
              pears 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 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 pa‐
              rameters 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-.

              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 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',
              all  words  on  the  line except for the current one will be ex‐
              cluded from the possible completions.

              The values `current' and `current-shown' are a bit like the  op‐
              posite  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  op‐
              tion 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 di‐
                     rectories are completed, not  when  completing  names  of
                     files.

              Excluded  values  act  in a similar fashion to values of the ig‐
              nored-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 com‐
              pleter can appear in the list of completers to restore  the  ig‐
              nored 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 in‐
              stead 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-sections
              This  style  is used with tags of the form `manuals.X' when com‐
              pleting names of manual pages. If set and the X in the tag  name
              matches the section number of the page being completed, the sec‐
              tion  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) in‐
              stead of performing completion when there is no non-blank  char‐
              acter  to the left of the cursor.  If it is set to `false', com‐
              pletion 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 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 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.

       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  comple‐
              tion list.  It is tested for all tags valid for the current com‐
              pletion, 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 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-dirs-first
              This is used by file completion and corresponds to a  particular
              setting  of the file-patterns style.  If set, the default direc‐
              tories 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 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,  and
              `%F',  `%f',  `%K',  `%k' for changing the foreground background
              colour, are also available, as is the form `%{...%}' for enclos‐
              ing escape sequences which display with zero (or, with a numeric
              argument, some other) width.

              After deleting this prompt the variable LISTPROMPT should be un‐
              set 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  sepa‐
              rate  the  string  to  complete from a description when possible
              (e.g. when completing options).  It defaults to  `--'  (two  hy‐
              phens).

       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.

       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  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 `*' in‐
              serted.  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 placed before any  match  specifica‐
              tions  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 the section `Completion Matching Control'  in  zsh‐
              compwid(1).   For  examples  of this, see the description of the
              tag-order style.

              For notes comparing the use of this and the matcher-list  style,
              see under the 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
              the section `Completion Matching Control' in zshcompwid(1).  The
              completion system will try them one after another for each  com‐
              pleter  selected.   For  example, to try first simple completion
              and, if that generates no matches, case-insensitive completion:

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

              By default each specification replaces the  previous  one;  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.   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 _com‐
              plete:

                     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  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 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  ex‐
              plicitly 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  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 nu‐
              meric 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 de‐
              scriptions 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 de‐
              scription 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 `de‐
              fault' 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 op‐
              tion is set.

              If one of the values is explicitly set to `false', menu  comple‐
              tion 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' val‐
              ues  (`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 comple‐
              tion  can  be  activated   in   that   case   with   the   value
              `yes=long-list'  (Typically,  the  value  `select=long-list' de‐
              scribed 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 imple‐
              mented by the zsh/complist module.  The following values may ap‐
              pear 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 `se‐
              lect=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  interac‐
              tive  mode  to  be  entered  immediately  when menu selection is
              started; see the description of the zsh/complist module in  zsh‐
              modules(1) for a description of interactive mode.  Including the
              string  `search'  does the same for incremental search mode.  To
              select  backward  incremental   search,   include   the   string
              `search-backward'.

       muttrc If  set,  gives the location of the mutt configuration file.  It
              defaults to `~/.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 `al‐
              ways', 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 un‐
              set, or any other value, then the existing list  of  completions
              is  displayed if it is not already; otherwise, the standard com‐
              pletion list is generated; this  is  the  default  behaviour  of
              _oldlist.   However, if there is an old list and this style con‐
              tains 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 wid‐
              get, 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 al‐
              ready generated.

              As another example consider the _match completer: with  the  in‐
              sert-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 pro‐
              duce 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 correc‐
              tions, 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  de‐
              cide  if  the original string should be added as a possible com‐
              pletion.  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 ap‐
              proximate-num, where num is the number of errors that  were  ac‐
              cepted.

       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 contain‐
              ing  color  names  in the format of an X11 rgb.txt file.  If the
              style is not set but this file is found in one of various  stan‐
              dard locations it will be used as the default.

       path-completion
              This  is used by filename completion.  By default, filename com‐
              pletion examines all components of a path to see  if  there  are
              completions  of that component.  For example, /u/b/z can be com‐
              pleted  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-ex‐
              act-dirs.

              Even with the style set to `false', it is still possible to com‐
              plete  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 pre‐
              fix, 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, func‐
              tions, and parameters completion tags.

              For command options, this means that the initial  `-',  `+',  or
              `--'  must  be typed explicitly before option names will be com‐
              pleted.

              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 re‐
              quired before function or parameter names  starting  with  those
              characters will be completed.

              The default value for this style is `false' for function and pa‐
              rameter 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  ex‐
              ample,  on some Unices an initial `//' (double slash) has a spe‐
              cial meaning; setting this style to the string  `//'  will  pre‐
              serve 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_com‐
              plete_word bindable command to decide which words should be com‐
              pleted.

              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 in‐
              cluding slashes on both sides.  If an ordinary  file  completion
              fails  and  the word on the command line does not yet have a di‐
              rectory 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.  Typi‐
              cally the elements of the style will be set to restrict the num‐
              ber of directories beneath the current one to a manageable  num‐
              ber, 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 issu‐
              ing 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 mak‐
              ing 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 com‐
              pletion 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 de‐
              fault 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 nega‐
              tive number, the list is scrolled by a screenful minus  the  ab‐
              solute  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 sepa‐
              rately.  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 re‐
              moved after completion is finished.

       single-ignored
              This is used by the _ignored completer when there  is  only  one
              match.   If  its  value is `show', the single match will be dis‐
              played but not inserted.  If the value is `menu', then the  sin‐
              gle  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 dis‐
              abled.  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  par‐
              ticular  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 chronologi‐
              cally 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 expan‐
              sions.

       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 comple‐
              tions; 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 be‐
              ginning 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 his‐
              tory.  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  immedi‐
              ately 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 dis‐
              play 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 suf‐
              fix,  i.e.  if it is something like `~foo' or `$foo' rather than
              `~foo/' or `$foo/bar', unless that suffix itself contains  char‐
              acters  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-pat‐
              terns 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 ex‐
              ternal 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.  Nor‐
                     mally 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 hy‐
                     phen 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 ar‐
                     bitrary 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 descrip‐
                     tion  supplied by the completion function.  Spaces in the
                     description must be quoted with a backslash.  A `%d'  ap‐
                     pearing  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 match‐
              ing 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, set‐
              ting  other styles differently on each attempt, but still to use
              all the other tags without having to repeat them all.  For exam‐
              ple, 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-pat‐
              terns  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 `--', op‐
              tions beginning with a single `-' or `+' but containing multiple
              characters, and single-letter options will be displayed in sepa‐
              rate groups with different descriptions.

              Another  use of patterns is to try multiple match specifications
              one after another.  The matcher-list style offers something sim‐
              ilar, 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 argu‐
              ments 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  com‐
              mand  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 PRE‐
              FIX special parameter; see zshcompwid for a description of para‐
              meters which are special inside completion widgets.  Setting re‐
              ply  to  an empty array provides the default behaviour of trying
              all tags at once; setting it to an array containing only  a  hy‐
              phen 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  comple‐
              tions.   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 di‐
              rectory 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 infor‐
              mation (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,  _re‐
              trieve_cache, and _cache_invalid functions).  The directory con‐
              taining 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  un‐
              set, 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 com‐
              mands may use the accounts tag.

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

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

       word   This  is  used by the _list completer, which prevents the inser‐
              tion 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 per‐
              formed  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  er‐
              rors  can be specified by the max-errors style; see the descrip‐
              tion 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 ac‐
              cepted  to generate the corrections and the original string, re‐
              spectively.

              The completer progressively increases the number of  errors  al‐
              lowed  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.

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

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

              See _description for a description of tag and descr.

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

              This function takes no arguments.

       _cmdstring
              Completes  an external command as a single argument, as for sys‐
              tem(...).

       _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  ef‐
              fect is similar to spell-checking.  It is based on _approximate,
              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  _ap‐
              proximate  completer or, as in the example, just before it.  Us‐
              ing it after the _approximate completer is  useless  since  _ap‐
              proximate will at least generate the corrected strings generated
              by the _correct completer -- and probably more.

       _expand
              This  completer function does not really perform completion, but
              instead checks if the word on the command line is  eligible  for
              expansion  and,  if  it is, gives detailed 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.

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

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

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

       _history
              Complete  words  from  the  shell's command  history.  This 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 un‐
              til  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 un‐
              less the insert-unambiguous style is set to `true'; see the  de‐
              scription 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  be‐
              have  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.

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

       _prefix
              This  completer  can  be  used to try completion with the suffix
              (everything after the cursor) ignored.  In other words, the 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  --  ex‐
              cept,  of course, the _prefix completer itself.  Furthermore, if
              this completer appears more than once in the list of  completers
              only  those  completers not already tried by the last invocation
              of _prefix will be called.

              For example, consider this global completer style:

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

              Here, the _prefix completer tries normal completion but ignoring
              the suffix.  If that doesn't generate any matches,  and  neither
              does  the  call to the _correct completer 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.

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

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

              $hash

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

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

       _bash_completions
              This function is used by two  widgets,  _bash_complete-word  and
              _bash_list-choices.   It  exists  to  provide compatibility with
              completion bindings in bash.  The last character of the  binding
              determines  what is completed: `!', command names; `$', 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, _ex‐
              pand_alias tries to complete the word to a full alias name with‐
              out expanding it.  It leaves the cursor directly after the  com‐
              pleted 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.  Be‐
              fore 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 de‐
              fault.  However, it can be used to define a widget and will then
              store the name of the widget in the function field of  the  con‐
              text and call the completion system.  This allows custom comple‐
              tion  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  ex‐
              ample `_files -/', in which case the function with any arguments
              will  be  called to generate the completions.  Unambiguous parts
              of the function name will  be  completed  automatically  (normal
              completion  is  not  available  at  this point) until a space is
              typed.

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

              A very restricted set of  editing  commands  is  available  when
              reading  the  string:  `DEL' and `^H' delete the last character;
              `^U' deletes the line, and `^C' and  `^G'  abort  the  function,
              while  `RET'  accepts  the  completion.  Note the string is used
              verbatim as a command line, so arguments must be quoted  in  ac‐
              cordance 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 de‐
              pends on the information available from the completion functions
              called, which in turn is determined by the user's own styles and
              other settings.

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

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

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

       _all_labels [ -x ] [ -12VJ ] tag name descr [ command arg ... ]
              This is a convenient interface to the _next_label  function  be‐
              low,  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 al‐
              lows _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 [ -O name ] [ -C name ] spec ...
              This function is useful in simple cases where multiple tags  are
              available.   Essentially  it  implements a loop like the one de‐
              scribed 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:de‐
              scr:action'.  The tags are offered using _tags and if the tag is
              requested, the action is executed with the given description de‐
              scr.  The actions are those accepted by the _arguments  function
              (described below), with the following exceptions:
              •      The `->state' and `=...' forms are not supported.


              •      The  `((a\:bar  b\:baz))' form does not need the colon to
                     be escaped,  since  the  specs  have  no  colon-separated
                     fields after the action.


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

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

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

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

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

              Like _tags this function supports the -C option to give  a  dif‐
              ferent name for the argument context field.


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

              Options Overview

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

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

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

              The options of _arguments have the following meanings:

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

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

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

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

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

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

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

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

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

                            foobar -x -- -y

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

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

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

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

              -0     When  populating values of the `opt_args' associative ar‐
                     ray, don't backslash-escape colons  and  backslashes  and
                     use  NUL  rather  than colon for joining multiple values.
                     This option is described in more detail below, under  the
                     heading specs: actions.

              specs: overview

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

              n:message:action
              n::message:action
                     This  describes  the  n'th  normal argument.  The message
                     will be printed above the matches generated and  the  ac‐
                     tion  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 ar‐
                     ray and the CURRENT special parameter are modified to re‐
                     fer only to the normal arguments when the action is  exe‐
                     cuted or evaluated.  With three colons before the message
                     they  are  modified to refer only to the normal arguments
                     covered by this description.

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

                     The following forms are available for  the  initial  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  re‐
                            peated.   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  op‐
                            tion  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 di‐
                            rectly 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 ar‐
                            gument is described for this optspec, the value of
                            the style is displayed, with any appearance of the
                            sequence `%d' in it replaced by the message of the
                            first optarg that follows the optspec; see below.

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

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

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

                            This  group may be repeated for options which take
                            multiple arguments.  In other words, :message1:ac‐
                            tion1:message2:action2 specifies that  the  option
                            takes two arguments.

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

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

              Each of the forms above may be preceded by a list in parentheses
              of option names and argument numbers.  If the given option is on
              the  command line, the options and arguments indicated in paren‐
              theses  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 indi‐
              cate various other items that should not  be  applied  when  the
              current specification is matched: a single star (*) for the rest
              arguments  (i.e.  a  specification of the form `*:...'); a colon
              (:) for all normal (non-option-) arguments; and a hyphen (-) for
              all options.  For example, if `(*)' appears before an option and
              the option appears on the command line, the  list  of  remaining
              arguments  (those  shown in the above table beginning with `*:')
              will not be completed.

              To aid in reuse of specifications, it is possible to precede any
              of the forms above with `!'; then the form  will  no  longer  be
              completed,  although  if  the  option or 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'.

              specs: actions


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

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

              The forms for action are as follows.

               (single unquoted space)
                     This  is  useful  where an argument is required but it is
                     not possible or 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 pos‐
                     sible match.  Note the backslash before the  colon.   For
                     example,

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

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

              ->string
                     In this form, _arguments processes the arguments and  op‐
                     tions  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  im‐
                     plement a state machine can use this type of action.

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

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

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

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

                            local context state state_descr line
                            typeset -A opt_args

                     to prevent _arguments from altering the  global  environ‐
                     ment.

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

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

                     This is most useful with one of the specifiers  that  re‐
                     strict  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 _argu‐
                     ments  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 ac‐
                     tion 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 descrip‐
                     tions of options and arguments, is  correctly  passed  to
                     the  completion  command.  These additional arguments are
                     taken from the array parameter `expl'; this will  be  set
                     up  before executing the action and hence may be referred
                     to inside it, typically  in  an  expansion  of  the  form
                     `$expl[@]' which preserves empty elements of the array.

              During  the  performance  of the action the array `line' will be
              set to the normal arguments from  the  command  line,  i.e.  the
              words from the command line after the command name excluding all
              options and their arguments.  Options are stored in the associa‐
              tive  array `opt_args' with option names as keys and their argu‐
              ments as the values.  By default, all colons and backslashes  in
              the  value  are  escaped  with backslashes, and if an option has
              multiple arguments (for example, when using an  optspec  of  the
              form `*optspec'), they are joined with (unescaped) colons.  How‐
              ever, if the -0 option was passed, no backslash escaping is per‐
              formed,  and multiple values are joined with NUL bytes.  For ex‐
              ample, after `zsh -o foo:foo -o bar:bar -o <TAB>', the  contents
              of `opt_args' would be

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

              by default, and

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

              if _arguments had been called with the -0 option.

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

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

              The option -C tells _arguments to modify the curcontext  parame‐
              ter  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.

              Grouping Options

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

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

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

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

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

              Specifying Multiple Sets of Arguments

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

              Specifications before the first set and from any group are  com‐
              mon to all sets. For example:

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

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

              As  for groups, the name of a set may appear in exclusion lists,
              either alone or preceding a normal option or argument specifica‐
              tion.

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

              Deriving spec forms from the help output

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

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

              For example:

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

              Here, `yes' and `no' will be completed as the  argument  of  op‐
              tions  whose description ends in a star; file names will be com‐
              pleted for options that contain the substring `=FILE' in the de‐
              scription; 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
              argument for an option is optional.  This can be  specified  ex‐
              plicitly by doubling the colon before the message.

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

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

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

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

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

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

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

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

              Miscellaneous notes

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

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

                     _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 ar‐
              gument 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, de‐
              scribed as `paper size' for which only the strings `letter'  and
              `A4' will be completed.

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

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

       _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
                         local -a oldp
                         oldp=( "$1"(Nm+7) )
                         (( $#oldp ))
                     }

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

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

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

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

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

       _combination [ -s pattern ] tag style spec ... field opts ...
              This  function  is used to complete combinations of values,  for
              example pairs of 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  al‐
              ready  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 values for the different fields  are  separated  by
              colons.   This can be altered with the option -s to _combination
              which specifies a pattern.  Typically this is a character class,
              as for example `-s "[:@]"' in the case of the users-hosts style.
              Each `field=pattern'  specification  restricts  the  completions
              which apply to elements of the style with appropriately matching
              fields.

              If no style with the given name is defined for the given tag, or
              if  none  of  the strings in style's value match, but a function
              name of the required field preceded by an underscore is defined,
              that function will be called to generate the matches.  For 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.

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

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

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

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

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

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


       _describe [-12JVx] [ -oO | -t tag ] descr name1 [ name2 ] [ opt ... ]
                 [ -- name1 [ name2 ] [ opt ... ] ... ]
              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 array name1 contains the possible completions
              with their descriptions in  the  form  `completion:description'.
              Any  literal  colons  in  completion must be quoted with a back‐
              slash.  If a name2 is given, it should have the same  number  of
              elements  as  name1; in this case the corresponding elements are
              added as possible completions instead of the completion  strings
              from  name1.   The  completion list will retain the descriptions
              from name1.  Finally, a set of completion options can appear.

              If the option  `-o'  appears  before  the  first  argument,  the
              matches  added will be treated as names of command options (N.B.
              not shell options), typically following a `-', `--'  or  `+'  on
              the  command  line.  In this case _describe uses the prefix-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'.

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

              If selected by the list-grouped style, strings with the same de‐
              scription 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, ignore-line, ig‐
              nored-patterns,  group-name and sort.  The format style is first
              tested for the given tag and then for the descriptions tag if no
              value was found, while the remainder are only tested for the tag
              given as the first argument.  The  function  also  calls  _setup
              which tests some more styles.

              The  string  returned by the format style (if any) will be 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  no  additional
              specs  are given but the description in descr conforms to a com‐
              mon form then further escape sequences are set for  elements  of
              that  description.  These elements correspond to a default value
              (`%o'), the units (`%m') range of acceptable values  (`%r')  and
              the  remaining initial part of the description (`%h').  The form
              the description takes consists of specifying the units and range
              in parentheses and the default value in square brackets, for ex‐
              ample:

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

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

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

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

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

                     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.

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

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

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

       _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 strings.  The first completion function to
              be defined for one of the contexts in the list is used to gener‐
              ate  matches.   Typically, the last string is -default- to cause
              the function for default completion to be used as a fallback.

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

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

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

              -n plugin
                     Complete aliases from plugin.

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

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

              Writing plugins

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

       _files The function _files is a wrapper around _path_files. It supports
              all  of  the  same  functionality, with some enhancements -- no‐
              tably, it respects the  list-dirs-first  style,  and  it  allows
              users  to  override  the behaviour of the -g and -/ options with
              the file-patterns style. _files should  therefore  be  preferred
              over _path_files in most cases.

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

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

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

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

              The  pattern may be preceded by any of the options understood by
              compadd that are passed down from _description, namely  -M,  -J,
              -V,  -1,  -2,  -n,  -F and -X.  All of these options will be ig‐
              nored.  This fits in conveniently with the argument-passing con‐
              ventions 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 al‐
              ready  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 al‐
              ways 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.  Note that  this  option  does
              not disable the `%'-sequence parsing done by compadd.

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

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

       _multi_parts [ -i ] sep array
              The argument sep is a separator character.  The array may be ei‐
              ther  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 [ option ... ]
              This  function  is used to implement the loop over different tag
              labels for a particular tag as described above for the tag-order
              style.  On each call it checks to see if there are any more  tag
              labels;  if there is it returns status zero, otherwise non-zero.
              As this function requires a current tag to be set, it  must  al‐
              ways 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 [ -P | -p precommand ]
              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 -de‐
              fault- 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  precommand  specifiers such as nohup, removes the
              first word from the words array, decrements the CURRENT  parame‐
              ter,  then calls `_normal -p $service'.  The effect is that `no‐
              hup cmd ...' is treated in the same way as `cmd ...'.

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

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

              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.

       _numbers [ option ... ] [ description ] [ suffix ... ]
              This can be used where a number is followed by a suffix to indi‐
              cate the units.  The unit suffixes are completed and can also be
              included  in the description used when completion is invoked for
              the preceding number.

              In addition to common compadd options, _numbers accepts the fol‐
              lowing options:

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

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

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

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

              -d default
                     Specify the default value.

              -N     Allow negative numbers.  This is implied if the range in‐
                     cludes a negative.

              -f     Allow decimal numbers.

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

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

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

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

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

       _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 be‐
              fore 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/in‐
              clude/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,  am‐
              biguous,  special-dirs,  list-suffixes  and  file-sort described
              above.


       _pick_variant [ -b builtin-label ] [ -c command ] [ -r name ]
                     label=pattern ... label [ arg ... ]
              This function is used to resolve situations where a single  com‐
              mand  name  requires  more than one type of handling, either be‐
              cause 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  arg  ...'  contains pattern, then label is selected as the
              label for the command variant.  If none of the  patterns  match,
              the final command label is selected and status 1 is returned.

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

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

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

       _regex_arguments name spec ...
              This function generates a completion function name which matches
              the specifications specs, a set of regular  expressions  as  de‐
              scribed  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  re‐
              maining command line string contains no null character (implying
              the  remaining  word  is the one for which completions are to be
              generated).  The completion target is restricted to the  remain‐
              ing word and any actions for the corresponding patterns are exe‐
              cuted.   In this case, nothing is stripped from the command line
              string.  The order of evaluation of the actions  can  be  deter‐
              mined  by  the tag-order style; the various formats supported by
              _alternative can be used in action.  The descr is used for  set‐
              ting 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 re‐
              quired for the context to be matched, so that further  arguments
              may be completed after the abbreviated form.

              The second part of spec is a description for the word being 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 ar‐
              ray  mydb_add_cmds,  quite  possibly  by  a  previous  call   to
              _regex_words.

       _requested [ -x ] [ -12VJ ] tag [ name descr [ command [ arg ... ] ]
              This  function  is called to decide whether a tag already regis‐
              tered by a call to _tags (see below) has been requested  by  the
              user  and  hence  completion should be performed for it.  It re‐
              turns 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 im‐
              mediately  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  re‐
              turn  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 ar‐
              guments.  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.

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

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

       _setup tag [ group ]
              This function sets up the special parameters used by the 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 param ...
              This function, together with _retrieve_cache and _cache_invalid,
              implements a caching layer which can be used in  any  completion
              function.   Data obtained by costly operations are stored in pa‐
              rameters; 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 ] tag ... ]
              If  called  with  arguments,  these are taken to be the names of
              tags valid for completions in the current context.   These  tags
              are stored internally and sorted by using the tag-order style.

              Next, _tags is called repeatedly without arguments from the same
              completion  function.  This successively selects the first, 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 _re‐
              quested 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).

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

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

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

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

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

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

              All other arguments describe the possible values and their 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  ap‐
              pear  more  than once.  The second is described as `number', may
              appear more than once, and  takes  one  mandatory  argument  de‐
              scribed 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, state_descr,
              line, context and val_args:

                     local context state state_descr line
                     typeset -A val_args

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

              Note also that _values normally adds the character used  as  the
              separator between 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 call‐
              ing 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 in‐
              stead of context (as described above).

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

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

              Hence  to offer only one tag and immediately add the correspond‐
              ing matches with the given description:

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

              See also the use of _wanted in the example function in the  sub‐
              section `Dynamic named directories' in zshexpn(1).

              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.

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

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

       The standard variables are:

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

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

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

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.



ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:

       box; cbp-1 | cbp-1 l | l .  ATTRIBUTE TYPE ATTRIBUTE VALUE = Availabil‐
       ity   shell/zsh = Stability Volatile

NOTES
       Source code for open source software components in Oracle  Solaris  can
       be found at https://www.oracle.com/downloads/opensource/solaris-source-
       code-downloads.html.

       This software was built from source available at:
       https://github.com/oracle/solaris-userland

       The original community source was downloaded from:
       https://downloads.sourceforge.net/project/zsh/zsh/5.9/zsh-5.9.tar.xz

       Further information about this software can be found on the open source
       community website at https://www.zsh.org/.

zsh 5.9                          May 14, 2022                    ZSHCOMPSYS(1)
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