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
       o      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';

       o      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 see zshmod-
       ules(1).

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

       When a completion is requested, a dispatcher function  is  called;  see
       the  description of _main_complete in the list of control functions 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:
       o      those beginning `comp' are to be called directly; there are only
              a few of these;

       o      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.

       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 program-
       mable completion system.  When run it will define the functions,  comp-
       gen  and  complete  which correspond to the bash builtins with the same
       names.  It will then be possible to use completion  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=(...)')

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

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

       -command-
              A word in command position

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

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

       -equal-
              A word beginning with an equals sign

       -first-
              This  is  tried before any other completion function.  The func-
              tion called may set the _compskip parameter to  one  of  various
              values:  all:  no further completion is attempted; a string con-
              taining the substring patterns: no pattern completion  functions
              will  be  called;  a string containing default: the function for
              the `-default-' context will not be called,  but  functions  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  `-re-
       direct-,op,command',  where  op is the redirection operator and command
       is the name of the command on the line.  If there is no command on  the
       line yet, the command field will be empty.

       For the -value- context, the form is `-value-,name,command', where name
       is the name of the parameter 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:

       o      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.

       o      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.

       o      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.

       o      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.

       o      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.

       o      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) style pattern, and the name of the style itself, which must be
       matched exactly.  The following examples demonstrate  that  style  pat-
       terns  may  be  loosely  defined  for  styles that apply broadly, or as
       tightly defined as desired for styles that apply  in  narrower  circum-
       stances.

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

              zstyle ':completion:*' verbose yes

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

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

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

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

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

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

       The -e option to zstyle even allows completion function code to  appear
       as the argument to a style; this requires some understanding of the 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.  More precisely, strings are pre-
       ferred over patterns  (for  example,  `:completion::complete:::foo'  is
       more  specific  than  `:completion::complete:::*'), and longer patterns
       are preferred over shorter patterns.

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

       Style  names like those of tags are arbitrary and depend on the 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

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

       interfaces
              for network interfaces

       keymaps
              for names of zsh keymaps

       keysyms
              for names of X keysyms

       libraries
              for names of system libraries

       limits for system limits

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

       manuals
              for names of manual pages

       mailboxes
              for e-mail folders

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

       messages
              used to look up the format style for messages

       modifiers
              for names of X modifiers

       modules
              for modules (e.g. zsh modules)

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

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

       names  for all kinds of names

       newsgroups
              for USENET groups

       nicknames
              for nicknames of NIS maps

       options
              for command options

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

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

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

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

       parameters
              for names of parameters

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

       paths  used  to  look  up  the values of the expand, ambiguous and 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.

       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.  If the description given
              here contains itself a `%d', that is replaced with the  descrip-
              tion supplied by the completion function.

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

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

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

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

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

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

       file-sort
              The  standard filename completion function uses this style with-
              out a tag to determine  in  which  order  the  names  should  be
              listed;  menu completion will cycle through them in the same 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  ev-
              erything  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 con-
              texts 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).

       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-.

       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.

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

       ignored-patterns
              A  list  of  patterns;  any trial completion matching one of the
              patterns will be excluded from consideration.  The _ignored com-
              pleter  can  appear in the list of completers to restore the 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-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.

       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.

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

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

       last-prompt
              This  is  a more flexible form of the ALWAYS_LAST_PROMPT option.
              If it is `true', the completion system will try  to  return  the
              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.

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

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

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

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

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

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

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

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

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

       list-grouped
              If  this  style  is  `true' (the default), the completion system
              will try to make certain completion  listings  more  compact  by
              grouping  matches.   For example, options for 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-suffixes
              This style is used by the function that completes filenames.  If
              it is `true', and completion is attempted on a string containing
              multiple partially typed pathname components, all ambiguous com-
              ponents will be shown.  Otherwise, completion stops at the first
              ambiguous component.

       list-separator
              The value of this style is used in completion listing  to  sepa-
              rate  the  string  to  complete from a description when possible
              (e.g. when completing options).  It defaults to  `--'  (two  hy-
              phens).

       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_trTAB
              can be completed to Zle/zle_tricky.c.

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

       rehash If this is set when completing external commands,  the  internal
              list (hash) of commands will be updated for each search by 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 abso-
              lute  value  of  the  given  number of lines.  The default is to
              scroll by single lines.

       separate-sections
              This style is used with the manuals tag when completing names of
              manual  pages.   If it is `true', entries for different sections
              are added separately using tag names  of  the  form  `manual.X',
              where  X  is  the  section number.  When the group-name style is
              also in effect, pages from different sections will appear  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.  The de-
              fault 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  pa-
              rameters  which  are special inside completion widgets.  Setting
              reply to an empty array provides the default behaviour of trying
              all  tags  at once; setting it to an array containing only a 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), excluding the `->state' and `=...' forms.

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

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

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

              Like  _arguments,  this function uses _all_labels to execute the
              actions, which will loop over all sets of  tags.   Special  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:|=*

              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.  For options that have more than one  argu-
              ment  these  are  given as one string, separated by colons.  All
              colons and backslashes in the original  arguments  are  preceded
              with backslashes.

              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
              numbers' but does not offer completions.

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

              Example:

                     _example_caching_policy () {
                         # rebuild if cache is more than a week old
                         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.

       _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  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.

       _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)look-
                     ahead*' 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 matches...

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

              Like _tags this function supports the -C option to give  a  dif-
              ferent  name  for the argument context field.  The -x option has
              the same meaning as for _description.

       _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  arrays  compprefuncs and comppostfuncs may contain names of
              functions that are to be called immediately before or after com-
              pletion has been tried.  A function will only be called once un-
              less it explicitly reinserts itself 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.

zsh 5.8                        February 14, 2020                 ZSHCOMPSYS(1)

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