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zshcompsys(1)                                                    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
              directory';


       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
       describe.

       Besides  commands  names and contexts, the system employs two more con-
       cepts, styles and tags.  These provide ways for the user  to  configure
       the system's behaviour.

       Tags  play  a dual role.  They serve as a classification system for the
       matches, typically indicating a class of object that the user may  need
       to  distinguish.  For example, when completing arguments of the ls com-
       mand the user may prefer to try files before directories,  so  both  of
       these are tags.  They also appear as the rightmost element in a context
       specification.

       Styles modify various operations of the completion system, such as out-
       put formatting, but also what kinds of completers are used (and in what
       order), or which tags are examined.  Styles may  accept  arguments  and
       are  manipulated  using  the  zstyle  command  described in see zshmod-
       ules(1).

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

       When a completion is requested, a dispatcher function  is  called;  see
       the  description  of  _main_complete  in  the list of control functions
       below. This dispatcher decides which function should be called to  pro-
       duce the completions, and calls it. The result is passed to one or more
       completers, functions that implement individual completion  strategies:
       simple  completion, error correction, completion with error correction,
       menu selection, etc.

       More generally, the shell functions contained in the completion  system
       are of two types:
       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
       (`autoload -U compinstall' is recommended).  You can abort the  instal-
       lation any time you are being prompted for information, and your .zshrc
       will not be altered at all; changes only take place right at  the  end,
       where you are specifically asked for confirmation.


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

       To  initialize  the system, the function compinit should be in a direc-
       tory mentioned  in  the  fpath  parameter,  and  should  be  autoloaded
       (`autoload  -U  compinit'  is  recommended),  and  then  run  simply as
       `compinit'.  This will define a few utility functions, arrange for  all
       the necessary shell functions to be autoloaded, and will then re-define
       all widgets that do completion to use the new system.  If you  use  the
       menu-select  widget,  which  is  part  of  the zsh/complist module, you
       should make sure that that module is loaded before the call to compinit
       so  that  that  widget  is  also re-defined.  If completion styles (see
       below) are set up  to  perform  expansion  as  well  as  completion  by
       default,  and the TAB key is bound to expand-or-complete, compinit will
       rebind it to complete-word; this is necessary to use the  correct  form
       of expansion.

       Should  you need to use the original completion commands, you can still
       bind keys to the old widgets by putting a `.' in front  of  the  widget
       name, e.g. `.expand-or-complete'.

       To speed up the running of compinit, it can be made to produce a dumped
       configuration that will be read in on future invocations; this  is  the
       default,  but can be turned off by calling compinit with the option -D.
       The dumped file is .zcompdump in the  same  directory  as  the  startup
       files  (i.e.  $ZDOTDIR  or $HOME); alternatively, an explicit file name
       can be given  by  `compinit  -d  dumpfile'.   The  next  invocation  of
       compinit  will  read  the dumped file instead of performing a full ini-
       tialization.

       If the number of completion files changes, compinit will recognise this
       and produce a new dump file.  However, if the name of a function or the
       arguments in the first line of a #compdef function (as described below)
       change,  it is easiest to delete the dump file by hand so that compinit
       will re-create it the next time it is run.  The check performed to  see
       if  there are new functions can be omitted by giving the option -C.  In
       this case the dump file  will  only  be  created  if  there  isn't  one
       already.

       The  dumping  is  actually  done by another function, compdump, but you
       will only need to run this yourself if  you  change  the  configuration
       (e.g.  using  compdef)  and then want to dump the new one.  The name of
       the old dumped file will be remembered for this purpose.

       If the parameter _compdir is set, compinit uses it as a directory where
       completion  functions  can be found; this is only necessary if they are
       not already in the function search path.

       For security reasons compinit also  checks  if  the  completion  system
       would  use  files not owned by root or by the current user, or files in
       directories that are world- or group-writable or that are not owned  by
       root  or  by the current user.  If such files or directories are found,
       compinit will ask if the completion system should really be  used.   To
       avoid  these tests and make all files found be used without asking, use
       the option -u, and to make compinit silently ignore all insecure  files
       and  directories  use  the  option  -i.  This security check is skipped
       entirely when the -C option is given.

       The security check can be retried at any time by running  the  function
       compaudit.   This  is  the  same check used by compinit, but when it is
       executed directly any changes to fpath are made local to  the  function
       so they do not persist.  The directories to be checked may be passed as
       arguments; if none are given, compaudit uses fpath and _compdir to find
       completion  system  directories, adding missing ones to fpath as neces-
       sary.  To force a check of exactly the directories currently  named  in
       fpath,  set  _compdir  to  an  empty string before calling compaudit or
       compinit.

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


   Autoloaded files
       The convention for autoloaded functions used in completion is that they
       start with an underscore; as already mentioned, the fpath/FPATH parame-
       ter must contain the directory in which they are stored.   If  zsh  was
       properly  installed on your system, then fpath/FPATH automatically con-
       tains the required directories for the standard functions.

       For incomplete installations, if compinit does not  find  enough  files
       beginning with an underscore (fewer than twenty) in the search path, it
       will try to find more by adding the directory _compdir  to  the  search
       path.  If that directory has a subdirectory named Base, all subdirecto-
       ries will be added to the path.  Furthermore, if the subdirectory  Base
       has  a subdirectory named Core, compinit will add all subdirectories of
       the subdirectories is to the path: this allows the functions to  be  in
       the same format as in the zsh source distribution.

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

       The tags are:

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

              Each  name may also be of the form `cmd=service'.  When complet-
              ing the command cmd, the function typically behaves  as  if  the
              command   (or  special  context)  service  was  being  completed
              instead.  This provides a way of altering the behaviour of func-
              tions that can perform many different completions.  It is imple-
              mented by setting the parameter $service when calling the  func-
              tion;  the  function may choose to interpret this how it wishes,
              and simpler functions will probably ignore it.

              If the #compdef line contains one of the options -p or  -P,  the
              words  following are taken to be patterns.  The function will be
              called when completion is attempted for  a  command  or  context
              that  matches  one  of  the patterns.  The options -p and -P are
              used to specify patterns to be tried before or after other  com-
              pletions  respectively.  Hence -P may be used to specify default
              actions.

              The option -N is used after a list following -p or -P; it speci-
              fies that remaining words no longer define patterns.  It is pos-
              sible to toggle between the three options as many times as  nec-
              essary.

       #compdef -k style key-sequences...
              This  option  creates  a widget behaving like the builtin widget
              style and binds it to the  given  key-sequences,  if  any.   The
              style  must  be  one of the builtin widgets that perform comple-
              tion, namely complete-word, delete-char-or-list,  expand-or-com-
              plete,  expand-or-complete-prefix,  list-choices, menu-complete,
              menu-expand-or-complete,  or  reverse-menu-complete.    If   the
              zsh/complist  module  is  loaded  (see zshmodules(1)) the widget
              menu-select is also available.

              When one of the key-sequences is typed, the function in the file
              will  be  invoked to generate the matches.  Note that a key will
              not be re-bound if 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-sequences ...
              This  is  similar to -k except that only one key-sequences argu-
              ment may be given for each widget-name style pair.  However, the
              entire  set  of three arguments may be repeated with a different
              set of arguments.  Note in particular that the widget-name  must
              be  distinct  in  each  set.  If it does not begin with `_' this
              will be added.  The widget-name should not clash with  the  name
              of  any existing widget: names based on the name of the function
              are most useful.  For example,

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

              (all on one line) defines a widget _foo_complete for completion,
              bound  to  `^X^C',  and a widget _foo_list for listing, bound to
              `^X^D'.

       #autoload [ options ]
              Functions with the #autoload tag are marked for autoloading  but
              are  not  otherwise treated specially.  Typically they are to be
              called from within one of the completion functions.  Any options
              supplied  will  be passed to the autoload builtin; a typical use
              is +X to force the function to be loaded immediately.  Note that
              the -U and -z flags are always added implicitly.

       The  #  is part of the tag name and no white space is allowed after it.
       The #compdef tags use the compdef function described  below;  the  main
       difference is that the name of the function is supplied implicitly.

       The special contexts for which completion functions can be defined are:

       -array-value-
              The right hand side of an array-assignment (`foo=(...)')

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

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

       -command-
              A word in command position

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

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

       -equal-
              A word beginning with an equals sign

       -first-
              This  is  tried before any other completion function.  The func-
              tion called may set the _compskip parameter to  one  of  various
              values:  all:  no further completion is attempted; a string con-
              taining the substring patterns: no pattern completion  functions
              will  be  called;  a string containing default: the function for
              the `-default-'  context  will  not  be  called,  but  functions
              defined for commands will

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

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

       -redirect-
              The word after a redirection operator.

       -subscript-
              The contents of a parameter subscript.

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

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

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

       The contexts -redirect- and -value- allow extra context-specific infor-
       mation.  (Internally, this is handled by the functions for each context
       calling  the function _dispatch.)  The extra information is added sepa-
       rated by commas.

       For the -redirect- context, the extra information is in the form  `-re-
       direct-,op,command',  where  op is the redirection operator and command
       is the name of the command on the line.  If there is no command on  the
       line yet, the command field will be empty.

       For the -value- context, the form is `-value-,name,command', where name
       is the name of the parameter.  In the case of elements of  an  associa-
       tive  array,  for  example  `assoc=(key  <TAB>',  name  is  expanded to
       `name-key'.  In certain special  contexts,  such  as  completing  after
       `make  CFLAGS=',  the  command part gives the name of the command, here
       make; otherwise it is empty.

       It is not necessary to define fully specific completions as  the  func-
       tions  provided  will  try  to  generate  completions  by progressively
       replacing the elements with `-default-'.  For example, when  completing
       after  `foo=<TAB>',  _value will try the names `-value-,foo,' (note the
       empty          command          part),          `-value-,foo,-default-'
       and`-value-,-default-,-default-', in that order, until it finds a func-
       tion to handle the context.

       As an example:

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

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

       Also:

              compdef _foo -value-,-default-,-default-

       specifies  that  _foo provides completions for the values of parameters
       for which no special function has been defined.  This is  usually  han-
       dled by the function _value itself.

       The  same  lookup  rules  are used when looking up styles (as described
       below); for example

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

       is another way to make  completion  after  `2>  <TAB>'  complete  files
       matching `*.log'.


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

       compdef [ -an ] function names... [ -[pP] patterns... [ -N names... ] ]
       compdef -d names...
       compdef -k [ -an ] function style key-sequences...
       compdef -K [ -an ] function name style key-sequences ...
              The first form defines the function to call  for  completion  in
              the given contexts as described for the #compdef tag above.

              Alternatively,  all  the  arguments  may have the form `cmd=ser-
              vice'.   Here  service  should  already  have  been  defined  by
              `cmd1=service' lines in #compdef files, as described above.  The
              argument for cmd will be completed in the same way as service.

              The function argument may alternatively be a  string  containing
              any  shell  code.   The  string  will be executed using the eval
              builtin command to generate completions.  This provides a way of
              avoiding  having to define a new completion function.  For exam-
              ple, to complete files ending in `.h' as arguments to  the  com-
              mand foo:

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

              The  option  -n prevents any completions already defined for the
              command or context from being overwritten.

              The option -d deletes any completion defined for the command  or
              contexts listed.

              The  names  may  also contain -p, -P and -N options as described
              for the #compdef tag.  The effect on the argument list is  iden-
              tical,  switching  between  definitions  of  patterns tried ini-
              tially, patterns tried finally, and  normal  commands  and  con-
              texts.

              The  parameter $_compskip may be set by any function defined for
              a pattern context.  If it is set to a value containing the  sub-
              string  `patterns' none of the pattern-functions will be called;
              if it is set to a value containing the substring `all', no other
              function will be called.

              The  form  with  -k  defines  a widget with the same name as the
              function that will be called for each of the key-sequences; this
              is  like  the #compdef -k tag.  The function should generate the
              completions needed and will otherwise behave  like  the  builtin
              widget  whose  name is given as the style argument.  The widgets
              usable  for  this   are:   complete-word,   delete-char-or-list,
              expand-or-complete,   expand-or-complete-prefix,   list-choices,
              menu-complete,  menu-expand-or-complete,  and  reverse-menu-com-
              plete,  as  well  as  menu-select  if the zsh/complist module is
              loaded.  The option -n prevents the key being  bound  if  it  is
              already to bound to something other than undefined-key.

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

              Wherever  applicable, the -a option makes the function autoload-
              able, equivalent to autoload -U function.

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

              compdef _pids foo

       uses the function _pids to complete process IDs for the command foo.

       Note  also the _gnu_generic function described below, which can be used
       to complete options for commands that understand the `--help' option.



COMPLETION SYSTEM CONFIGURATION

       This section gives a short overview of how the completion system works,
       and  then  more  detail on how users can configure how and when matches
       are generated.


   Overview
       When completion is attempted somewhere on the command line the  comple-
       tion  system first works out the context.  This takes account of a num-
       ber of things including the command word (such as `grep' or `zsh')  and
       options  to which the current word may be an argument (such as the `-o'
       option to zsh which takes a shell option as an argument).

       This context information is condensed into a string consisting of  mul-
       tiple  fields  separated by colons, referred to simply as `the context'
       in the remainder of the documentation.  This is used to look up styles,
       context-sensitive  options that can be used to configure the completion
       system.  The context used for lookup may vary during the same  call  to
       the completion system.

       The  context string always consists of a fixed set of fields, separated
       by colons and with a leading colon before the first, in the form  :com-
       pletion:function:completer:command:argument:tag.   These  have the fol-
       lowing meaning:

       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
              below.


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

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

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

              dvips -o ...

       and the completion function will generate filenames.

       Usually completion will be tried for all  possible  tags  in  an  order
       given  by  the  completion  function.   However, this can be altered by
       using the tag-order style.  Completion is then restricted to  the  list
       of given tags in the given order.

       The  _complete_help  bindable  command  shows all the contexts and tags
       available for completion at a particular point.  This provides an  easy
       way  of  finding  information  for  tag-order  and other styles.  It is
       described in the section `Bindable Commands' below.

       Styles determine such things as how the matches  are  generated,  simi-
       larly  to  shell options but with much more control.  They can have any
       number of strings as their value.  They are  defined  with  the  zstyle
       builtin command (see zshmodules(1)).

       When  looking  up styles the completion system uses full context names,
       including the tag.  Looking up the value of a style therefore  consists
       of two things:  the context, which may be matched as a pattern, and the
       name of the style itself, which must be given exactly.

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

              zstyle ':completion:*' verbose yes

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

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

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

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

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

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

       The  -e option to zstyle even allows completion function code to appear
       as the argument to a style; this requires  some  understanding  of  the
       internals  of completion functions (see see zshcompwid(1))).  For exam-
       ple,

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

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

       Note  that  the  order in which styles are defined does not matter; the
       style mechanism uses the most specific possible match for a  particular
       style to determine the set of values.  More precisely, strings are pre-
       ferred over patterns (for example, `:completion::complete:foo' is  more
       specific  than `:completion::complete:*'), and longer patterns are pre-
       ferred over shorter patterns.

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


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

       accounts
              used to look up the users-hosts style

       all-expansions
              used by the _expand completer when adding the single string con-
              taining all possible expansions

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

       arguments
              for arguments to a command

       arrays for names of array parameters

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

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

       builtins
              for names of builtin commands

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

       colormapids
              for X colormap ids

       colors for color names

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

       contexts
              for contexts in arguments to the zstyle builtin command

       corrections
              used by the _approximate and _correct  completers  for  possible
              corrections

       cursors
              for cursor names used by X programs

       default
              used  in  some  contexts to provide a way of supplying a default
              when more specific tags are also valid.  Note that this  tag  is
              used when only the function field of the context name is set

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

       devices
              for names of device special files

       directories
              for names of directories

       directory-stack
              for entries in the directory stack

       displays
              for X display names

       domains
              for network domains

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

       extensions
              for X server extensions

       file-descriptors
              for numbers of open file descriptors

       files  the generic file-matching tag used by functions completing file-
              names

       fonts  for X font names

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

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

       globbed-files
              for filenames when the name has been generated by pattern match-
              ing

       groups for names of user groups

       history-words
              for words from the history

       hosts  for hostnames

       indexes
              for array indexes

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

       interfaces
              for network interfaces

       keymaps
              for names of zsh keymaps

       keysyms
              for names of X keysyms

       libraries
              for names of system libraries

       limits for system limits

       local-directories
              for  names of directories that are subdirectories of the current
              working directory when completing arguments of  cd  and  related
              builtin commands (compare path-directories)

       manuals
              for names of manual pages

       mailboxes
              for e-mail folders

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

       messages
              used to look up the format style for messages

       modifiers
              for names of X modifiers

       modules
              for modules (e.g. zsh modules)

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

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

       names  for all kinds of names

       newsgroups
              for USENET groups

       nicknames
              for nicknames of NIS maps

       options
              for command options

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

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

       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.

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

       add-space
              This style is used by the _expand completer.  If it is true (the
              default),  a  space  will  be inserted after all words resulting
              from the expansion, or a slash in the case of  directory  names.
              If  the  value is `file', the completer will only add a space to
              names of existing files.  Either a boolean  true  or  the  value
              `file' may be combined with `subst', in which case the completer
              will not add a space to words generated from the expansion of  a
              substitution of the form `$(...)' or `${...}'.

              The  _prefix completer uses this style as a simple boolean value
              to decide if a space should be inserted before the suffix.

       ambiguous
              This applies when completing non-final  components  of  filename
              paths,  in  other  words  those with a trailing slash.  If it is
              set, the cursor is left after  the  first  ambiguous  component,
              even  if  menu completion is in use.  The style is always tested
              with the paths tag.

       assign-list
              When completing after an equals sign that is being treated as an
              assignment,  the  completion  system normally completes only one
              filename.  In some cases the value  may be a list  of  filenames
              separated  by colons, as with PATH and similar parameters.  This
              style can be set to a list of patterns  matching  the  names  of
              such parameters.

              The  default  is  to  complete  lists  when the word on the line
              already contains a colon.

       auto-description
              If set, this style's value will be used as the  description  for
              options  that are not described by the completion functions, but
              that have exactly one argument.  The sequence `%d' in the  value
              will  be replaced by the description for this argument.  Depend-
              ing on personal preferences, it may be useful to set this  style
              to  something  like  `specify: %d'.  Note that this may not work
              for some commands.

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

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

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

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

       call-command
              This style is used in the function for commands such as make and
              ant where calling the command directly to generate matches  suf-
              fers  problems such as being slow or, as in the case of make can
              potentially 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
              options.  Hence unless the value of this style is  true  options
              will  not be completed, even after an initial -.  If it is true,
              options will be completed after an initial - unless there  is  a
              preceding -- on the command line.

       completer
              The  strings  given as the value of this style provide the names
              of the completer functions to use. The available completer func-
              tions are described in the section `Control Functions' below.

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

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

              Here, completion will call the _complete completer  twice,  once
              using  `complete' and once using `complete-foo' in the completer
              field of the context.  Normally, using the same  completer  more
              than  once  only makes sense when used with the `functions:name'
              form, because otherwise the context name will be the same in all
              calls to the completer; possible exceptions to this rule are the
              _ignored and _prefix completers.

              The default value for this style is `_complete  _ignored':  only
              completion  will be done, first using the ignored-patterns style
              and the $fignore array and then without ignoring matches.

       condition
              This style is used by the _list completer function to decide  if
              insertion  of  matches  should  be  delayed unconditionally. The
              default is `true'.

       delimiters
              This style is used when adding a delimiter for use with  history
              modifiers  or glob qualifiers that have delimited arguments.  It
              is an array of preferred delimiters to add.  Non-special charac-
              ters are preferred as the completion system may otherwise become
              confused.  The default list is :, +, /, -, %.  The list  may  be
              empty to force a delimiter to be typed.

       disabled
              If  this is set to `true', the _expand_alias completer and bind-
              able command will try to  expand  disabled  aliases,  too.   The
              default is `false'.

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

       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 :complete: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
              ignored-patterns style is not applied to it.  This makes it pos-
              sible  to  override  a  set of matches completely by setting the
              ignored patterns to `*'.

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

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

       fake-files
              This style is used when completing files and looked up without a
              tag.   Its values are of the form `dir:names...'.  This will add
              the names (strings separated by spaces) as possible matches when
              completing  in  the  directory dir, even if no such files really
              exist.  The dir may be a pattern; pattern characters  or  colons
              in  dir  should  be 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.  It can also be used for  directories  for  which
              one does not have read permission.

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

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

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

                     zmodload -i zsh/stat
                     disable stat

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

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

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

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

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

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

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

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

              The pattern is a pattern that is to be used  to  generate  file-
              names.   Any  occurrence of the sequence `%p' is replaced by any
              pattern(s) passed by the function calling _files.  Colons in the
              pattern  must  be  preceded  by a backslash to make them distin-
              guishable from the colon before the tag.  If more than one  pat-
              tern  is  needed, the patterns can be given inside braces, sepa-
              rated by commas.

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

              The  tag  may also be followed by an optional second colon and a
              description, which will be used for the `%d' in the value of the
              format style (if that is set) instead of the default description
              supplied by the completion function.  If the  description  given
              here  contains itself a `%d', that is replaced with the descrip-
              tion supplied by the completion function.

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

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

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

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

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

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

       file-sort
              The standard filename completion function uses this style  with-
              out  a  tag  to  determine  in  which  order the names should be
              listed; menu completion will cycle  through  them  in  the  same
              order.   The  possible values are: `size' to sort by the size of
              the file; `links' to sort by the number of links  to  the  file;
              `modification' (or `time' or `date') to sort by the last modifi-
              cation time; `access' to sort  by  the  last  access  time;  and
              `inode' (or `change') to sort by the last inode change time.  If
              the style is set to any other value, or is unset, files will  be
              sorted alphabetically by name.  If the value contains the string
              `reverse', sorting is done in the opposite order.  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.

       filter This is used by the LDAP plugin for e-mail address completion to
              specify the attributes to match against when filtering  entries.
              So  for  example,  if the style is set to `sn', matching is done
              against surnames.  Standard LDAP filtering  is  used  so  normal
              completion  matching is bypassed.  If this style is not set, the
              LDAP plugin is skipped.  You may also need to  set  the  command
              style to specify how to connect to your LDAP server.

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

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

       format If  this is set for the descriptions tag, its value is used as a
              string to  display  above  matches  in  completion  lists.   The
              sequence  `%d'  in  this  string  will  be replaced with a short
              description of what these matches are.   This  string  may  also
              contain the following sequences to specify output attributes, as
              described in the section EXPANSION OF PROMPT SEQUENCES  in  zsh-
              misc(1): `%B', `%S', `%U', `%F', `%K' and their lower case coun-
              terparts, as well as `%{...%}'.  `%F', `%K' and  `%{...%}'  take
              arguments  in  the same form as prompt expansion.  Note that the
              %G sequence is not available; an argument to `%{' should be used
              instead.

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

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

              Some completion functions display  messages  that  may  be  cus-
              tomised  by  setting this style for the messages tag.  Here, the
              `%d' is replaced with a message given by  the  completion  func-
              tion.

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

              It  is  possible to use printf-style field width specifiers with
              `%d' and similar escape sequences.  This is handled by the zfor-
              mat  builtin  command  from  the  zsh/zutil  module, see zshmod-
              ules(1).

       glob   This is used by the _expand completer.  If it is set  to  `true'
              (the default), globbing will be attempted on the words resulting
              from a previous substitution (see the substitute style) or  else
              the original string from the line.

       global If  this  is set to `true' (the default), the _expand_alias com-
              pleter and bindable command will try to expand global aliases.

       group-name
              The completion system can  group  different  types  of  matches,
              which  appear in separate lists.  This style can be used to give
              the names of groups for particular tags.  For example,  in  com-
              mand  position  the completion system generates names of builtin
              and external commands, names of  aliases,  shell  functions  and
              parameters  and reserved words as possible completions.  To have
              the external commands and shell functions listed separately:

                     zstyle ':completion:*:*:-command-:*:commands' group-name commands
                     zstyle ':completion:*:*:-command-:*:functions' group-name functions

              As a consequence, any match with the same tag will be  displayed
              in the same group.

              If  the  name  given is the empty string the name of the tag for
              the matches will be used as the name of the group.  So, to  have
              all  different  types  of  matches displayed separately, one can
              just set:

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

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

       group-order
              This  style is additional to the group-name style to specify the
              order for display of the groups defined by that  style  (compare
              tag-order,  which  determines  which completions appear at all).
              The groups named are shown in the given order; any other  groups
              are shown in the order defined by the completion function.

              For  example, to have names of builtin commands, shell functions
              and external commands appear in that order  when  completing  in
              command position:

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

       groups A list of names of UNIX groups.  If this is not set, group names
              are taken from the YP database or the file `/etc/group'.

       hidden If this is set to true, matches for the given context  will  not
              be listed, although any description for the matches set with the
              format style will be shown.  If it is set to `all', not even the
              description will be displayed.

              Note that the matches will still be completed; they are just not
              shown in the list.  To avoid having matches considered as possi-
              ble  completions  at all, the tag-order style can be modified as
              described below.

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

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

       ignore-line
              This is tested for each tag valid for  the  current  completion.
              If  it  is  set to `true', none of the words that are already on
              the line will be considered as possible completions.  If  it  is
              set  to `current', the word the cursor is on will not be consid-
              ered as a possible completion.   The  value  `current-shown'  is
              similar but only applies if the list of completions is currently
              shown on the screen.  Finally, if the style is set  to  `other',
              no  word apart from the current one will be considered as a pos-
              sible completion.

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

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

       ignore-parents
              The style is tested without a tag  by  the  function  completing
              pathnames  in  order to determine whether to ignore the names of
              directories already mentioned in the current word, or  the  name
              of the current working directory.  The value must include one or
              both of the following strings:

              parent The name of any directory whose path is already contained
                     in  the  word  on the line is ignored.  For example, when
                     completing after foo/../, the directory foo will  not  be
                     considered a valid completion.

              pwd    The  name  of  the  current working directory will not be
                     completed; hence, for example, completion after ../  will
                     not use the name of the current directory.

              In addition, the value may include one or both of:

              ..     Ignore  the  specified  directories only when the word on
                     the line contains the substring `../'.

              directory
                     Ignore the  specified  directories  only  when  names  of
                     directories  are  completed, not when completing names of
                     files.

              Excluded values act in  a  similar  fashion  to  values  of  the
              ignored-patterns style, so they can be restored to consideration
              by the _ignored completer.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       list-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
              unset for the the removal to take effect.

       list-rows-first
              This style is tested in the same way as  the  list-packed  style
              and  determines whether matches are to be listed in a rows-first
              fashion as if the LIST_ROWS_FIRST option were set.

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

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

       local  This  is for use with functions that complete URLs for which the
              corresponding files are available directly from the 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 `*'
              inserted.  If it is unset or set to the empty  string,  matching
              will only be performed with the `*' inserted.

       matcher
              This  style  is tested separately for each tag valid in the cur-
              rent context.  Its value is added to  any  match  specifications
              given  by  the  matcher-list  style.   It  should be in the form
              described in the section `Completion Matching Control'  in  zsh-
              compwid(1).

       matcher-list
              This style can be set to a list of match specifications that are
              to be applied everywhere. Match specifications are described  in
              the section `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.   For
              example,  to  use  the completers _complete and _prefix but only
              allow case-insensitive completion with _complete:

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

              User-defined names, as explained for the  completer  style,  are
              available.   This  makes  it  possible to try the same completer
              more than once with different match  specifications  each  time.
              For example, to try normal completion without a match specifica-
              tion, then normal  completion  with  case-insensitive  matching,
              then correction, and finally partial-word completion:

                     zstyle ':completion:*' completer _complete _correct _complete:foo
                     zstyle ':completion:*:complete:*' matcher-list \
                         '' 'm:{a-zA-Z}={A-Za-z}'
                     zstyle ':completion:*:foo:*' matcher-list \
                         'm:{a-zA-Z}={A-Za-z} r:|[-_./]=* r:|=*'

              If  the  style is unset in any context no match specification is
              applied.  Note also that some completers such  as  _correct  and
              _approximate  do not use the match specifications at all, though
              these completers will only ever  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
              explicitly  specify  case-insensitive  matching   if   that   is
              required.

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

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

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

              two errors are allowed if no numeric argument is given, but with
              a  numeric argument of six (as in `ESC-6 TAB'), up to six errors
              are accepted.  Hence with a value of `0 numeric', no  correcting
              completion will be attempted unless a numeric argument is given.

              If the value contains the string  `not-numeric',  the  completer
              will  not  try  to  generate  corrected completions when given a
              numeric argument, so in this case the  number  given  should  be
              greater  than zero.  For example, `2 not-numeric' specifies that
              correcting completion with two errors will usually be performed,
              but  if  a numeric argument is given, correcting completion will
              not be performed.

              The default value for this style is `2 numeric'.

       max-matches-width
              This style is used to determine the trade off between the  width
              of  the  display  used  for matches and the width used for their
              descriptions when the verbose style is  in  effect.   The  value
              gives  the number of display columns to reserve for the matches.
              The default is half the width of the screen.

              This has the most impact when  several  matches  have  the  same
              description  and  so  will  be grouped together.  Increasing the
              style will allow more matches to be grouped together; decreasing
              it will allow more of the description to be visible.

       menu   If  this  is  true in the context of any of the tags defined for
              the current completion menu completion will be used.  The  value
              for  a  specific  tag  will  take  precedence  over that for the
              `default' tag.

              If none of the values found in this way is true but at least one
              is  set  to `auto', the shell behaves as if the AUTO_MENU option
              is set.

              If one of the values is explicitly set to false, menu completion
              will  be  explicitly  turned  off,  overriding the MENU_COMPLETE
              option and other settings.

              In the form `yes=num', where `yes' may be any of the true values
              (`yes', `true', `on' and `1'), menu completion will be turned on
              if there are at least num matches.  In the form `yes=long', menu
              completion  will  be  turned  on if the list does not fit on the
              screen.  This does not activate menu completion  if  the  widget
              normally  only  lists  completions,  but  menu completion can be
              activated in that case with  the  value  `yes=long-list'  (Typi-
              cally, the value `select=long-list' described later is more use-
              ful as it provides control over scrolling.)

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

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

              If  the  value contains the string `select', menu selection will
              be started unconditionally.

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

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

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

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

              Finally,  it  is  possible to activate two special modes of menu
              selection.  The word `interactive' in the value causes  interac-
              tive  mode  to  be  entered  immediately  when menu selection is
              started; see the description of the zsh/complist module in  zsh-
              modules(1) for a description of interactive mode.  Including the
              string `search' does the same for incremental search  mode.   To
              select   backward   incremental   search,   include  the  string
              `search-backward'.

       muttrc If set, gives the location of the mutt configuration  file.   It
              defaults to `~/.muttrc'.

       numbers
              This is used with the jobs tag.  If it is `true', the shell will
              complete job numbers instead of the shortest unambiguous  prefix
              of  the job command text.  If the value is a number, job numbers
              will only be used if that many words from the  job  descriptions
              are  required to resolve ambiguities.  For example, if the value
              is `1', strings will only be used if  all  jobs  differ  in  the
              first word on their command lines.

       old-list
              This  is  used  by  the  _oldlist  completer.   If  it is set to
              `always', then  standard  widgets  which  perform  listing  will
              retain the current list of matches, however they were generated;
              this can be turned off explicitly with the value `never', giving
              the  behaviour  without the _oldlist completer.  If the style is
              unset, or any other value, then the existing list of completions
              is  displayed if it is not already; otherwise, the standard 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
              already generated.

              As  another  example  consider  the  _match  completer: with the
              insert-unambiguous style set to `true' it inserts only a  common
              prefix  string, if there is any.  However, this may remove parts
              of the original pattern, so that further completion  could  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
              decide 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
              approximate-num,  where  num  is  the number of errors that were
              accepted.

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

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

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

       path   The function that completes color names uses this style with the
              colors tag.  The value should be the pathname of a file 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-exact-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,  too,  is used for matches with a common prefix.  If it is
              set to `true' this common prefix must be typed by  the  user  to
              generate  the  matches.   In  the  case of command options, this
              means that the initial `-', `+', or `--' must be  typed  explic-
              itly before option names will be completed.

              The default value for this style is `true'.

       preserve-prefix
              This style is used when completing path names.  Its value should
              be a pattern matching an initial prefix of the word to  complete
              that  should  be  left  unchanged  under all circumstances.  For
              example, on some Unices an initial `//'  (double  slash)  has  a
              special meaning; setting this style to the string `//' will 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 singe number, only the last N words from the history
              will be completed.

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

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

       regular
              This style is used by the _expand_alias completer  and  bindable
              command.   If  set to `true' (the default), 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 making
              Internet  connections  to  retrieve  remote  information.   This
              includes the completion for the CVS command.

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

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

       select-prompt
              If this is set for the default tag, its value will be  displayed
              during  menu  selection (see the menu style above) when the 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
              default prompt is used when the value is the empty string.

       select-scroll
              This  style  is  tested for the default tag and determines how a
              completion list is scrolled during a  menu  selection  (see  the
              menu  style  above) when the completion list does not fit on the
              screen as a whole.  If the value is  `0'  (zero),  the  list  is
              scrolled  by  half-screenfuls;  if it is a positive integer, the
              list is scrolled by the given number of lines; if it is a  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
              default for this style is `false'.

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

       single-ignored
              This  is  used  by the _ignored completer when there is only one
              match.  If its value is `show', the single match  will  be  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   Many completion widgets call _description at  some  point  which
              decides  whether the matches are added sorted or unsorted (often
              indirectly via _wanted or _requested).  This style  can  be  set
              explicitly  to one of the usual true or false values as an over-
              ride.  If it is not set for the context, the standard  behaviour
              of the calling widget is used.

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

              If the calling widget explicitly requests unsorted matches, this
              is usually honoured.  However, the default (unsorted)  behaviour
              of  completion for the command history may be overridden by set-
              ting 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
              beginning with `../'.  Otherwise the value is `false'.

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

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

       stop   If  set  to  `true', the _history_complete_word bindable command
              will stop once when reaching the beginning or end  of  the  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
              external  commands  and shell functions.  Remaining tags will be
              tried if no completions are found.

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

              -      If  any  value  consists  of only a hyphen, then only the
                     tags specified in the other values are  generated.   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
                     hyphen turns off completion.

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

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

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

              tag:label:description
                     As before, but description will replace the `%d'  in  the
                     value of the format style instead of the default descrip-
                     tion supplied by the completion function.  Spaces in  the
                     description  must  be  quoted  with  a backslash.  A `%d'
                     appearing in description is replaced with the description
                     given by the completion function.

              In  any  of  the forms above the tag may be a pattern or several
              patterns in the form `{pat1,pat2...}'.  In this case all  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  `--',
              options beginning with a single `-' or `+' but containing multi-
              ple characters, and single-letter options will be  displayed  in
              separate groups with different descriptions.

              Another  use of patterns is to try multiple match specifications
              one after another.  The matcher-list style offers something 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
              parameters which are special inside completion widgets.  Setting
              reply to an empty array provides the default behaviour of trying
              all  tags  at  once;  setting  it  to an array containing only a
              hyphen disables the use of all tags and  hence  of  all  comple-
              tions.

              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 the urls tag  by  functions  com-
              pleting 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
              directory hierarchy can descend as deep as necessary.

              For example,

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

              allows  completion  of   all   the   components   of   the   URL
              ftp://ftp.zsh.org/pub/development  after  suitable commands such
              as `netscape' or `lynx'.  Note, however, that access methods and
              files  are  completed  separately,  so if the hosts style is set
              hosts can be completed without 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,
              _retrieve_cache,  and  _cache_invalid functions).  The directory
              containing the cache files can be changed  with  the  cache-path
              style.

       use-compctl
              If  this style is set to a string not equal to false, 0, no, and
              off, the completion system may use any completion specifications
              defined  with  the  compctl  builtin  command.   If the style is
              unset, this is done only if the zsh/compctl  module  is  loaded.
              The string may also contain the substring `first' to use comple-
              tions 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).

       use-perl
              Various parts of the function system use awk  to  extract  words
              from  files  or  command  output as it is universally available.
              However, many versions of awk have arbitrary limits on the  size
              of  input.   If  this  style  is set, perl will be used instead.
              This is almost always preferable if perl is  available  on  your
              system.

              Currently  this  is  only used in completions for `make', but it
              may be extended depending on authorial frustration.

       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
              errors  can  be  specified  by  the  max-errors  style;  see the
              description of approximate matching in zshexpn(1) for how errors
              are  counted.   Normally this completer will only be tried after
              the normal _complete completer:

                     zstyle ':completion:*' completer _complete _approximate

              This will give correcting completion if and only if normal  com-
              pletion  yields no possible completions.  When corrected comple-
              tions are found, the completer will normally start menu  comple-
              tion allowing you to cycle through these strings.

              This  completer uses the tags corrections and original when gen-
              erating the possible corrections and the original  string.   The
              format style for the former may contain the additional sequences
              `%e' and `%o' which will be replaced by  the  number  of  errors
              accepted  to  generate  the corrections and the original string,
              respectively.

              The completer  progressively  increases  the  number  of  errors
              allowed up to the limit by the max-errors style, hence if a com-
              pletion is found with one error, no completions with two  errors
              will be shown, and so on.  It modifies the completer name in the
              context to indicate the number of errors  being  tried:  on  the
              first  try  the completer field contains `approximate-1', on the
              second try `approximate-2', and so on.

              When _approximate is called from another function, the number of
              errors to accept may be passed with the -a option.  The argument
              is in the same format  as  the  max-errors  style,  all  in  one
              string.

              Note  that  this completer (and the _correct completer mentioned
              below) can be quite expensive to call, especially when  a  large
              number  of  errors are allowed.  One way to avoid this is to set
              up the completer style using the -e option  to  zstyle  so  that
              some  completers  are  only  used when completion is attempted a
              second time on the same string, e.g.:

                     zstyle -e ':completion:*' completer '
                       if [[ $_last_try != "$HISTNO$BUFFER$CURSOR" ]]; then
                         _last_try="$HISTNO$BUFFER$CURSOR"
                         reply=(_complete _match _prefix)
                       else
                         reply=(_ignored _correct _approximate)
                       fi'

              This uses the HISTNO parameter and the BUFFER and CURSOR special
              parameters  that are available inside zle and completion widgets
              to find out if the command line hasn't changed  since  the  last
              time completion was tried.  Only then are the _ignored, _correct
              and _approximate completers called.

       _complete
              This completer generates all  possible  completions  in  a  con-
              text-sensitive  manner, i.e. using the settings defined with the
              compdef function explained above and the current settings of all
              special parameters.  This gives the normal completion behaviour.

              To complete arguments of commands, _complete  uses  the  utility
              function  _normal,  which is in turn responsible for finding the
              particular function; it is described below.  Various contexts of
              the  form -context- are handled specifically. These are all men-
              tioned above as possible arguments to the #compdef tag.

              Before trying to find a function for a specific  context,  _com-
              plete  checks  if  the  parameter  `compcontext' is set. Setting
              `compcontext' allows the  usual  completion  dispatching  to  be
              overridden  which  is  useful  in places such as a function that
              uses vared for input. If it is set to an array, the elements are
              taken  to  be the possible matches which will be completed using
              the tag `values' and the description `value'. If it is set to an
              associative array, the keys are used as the possible completions
              and the values (if non-empty) are used as descriptions  for  the
              matches.  If `compcontext' is set to a string containing colons,
              it should be of the form `tag:descr:action'.  In this  case  the
              tag and descr give the tag and description to use and the action
              indicates what should be completed in one of the forms  accepted
              by the _arguments utility function described below.

              Finally, if `compcontext' is set to a string without colons, the
              value is taken as the name of the context to use and  the  func-
              tion defined for that context will be called.  For this purpose,
              there is a special context named -command-line-  that  completes
              whole command lines (commands and their arguments).  This is not
              used by the completion system itself but is nonetheless  handled
              when explicitly called.

       _correct
              Generate corrections, but not completions, for the current word;
              this is similar to _approximate but will not allow any number of
              extra  characters  at  the  cursor  as that completer does.  The
              effect is similar to spell-checking.  It is based  on  _approxi-
              mate, but the completer field in the context name is correct.

              For example, with:

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

              correction  will accept up to two errors.  If a numeric argument
              is given, correction will not be performed, but correcting  com-
              pletion  will be, and will accept as many errors as given by the
              numeric argument.  Without a numeric argument, first  correction
              and then correcting completion will be tried, with the first one
              accepting two errors and the second one accepting three  errors.

              When  _correct  is called as a function, the number of errors to
              accept may be given following the -a option.  The argument is in
              the same form a values to the accept style, all in one string.

              This  completer  function  is  intended  to  be used without the
              _approximate completer or, as in the example,  just  before  it.
              Using  it  after  the  _approximate  completer  is useless since
              _approximate will at least generate the corrected strings gener-
              ated by the _correct completer -- and probably more.

       _expand
              This  completer function does not really perform completion, but
              instead checks if the word on the command line is  eligible  for
              expansion  and,  if  it is, gives detailed control over how this
              expansion is done.  For this to happen,  the  completion  system
              needs  to  be invoked with complete-word, not expand-or-complete
              (the default binding for TAB), as otherwise the string  will  be
              expanded by the shell's internal mechanism before the completion
              system is started.  Note also this completer  should  be  called
              before the _complete completer function.

              The  tags used when generating expansions are all-expansions for
              the string containing all possible expansions,  expansions  when
              adding  the  possible  expansions as single matches and original
              when adding the original string from the  line.   The  order  in
              which  these strings are generated, if at all, can be controlled
              by the group-order and tag-order styles, as usual.

              The format string for all-expansions and for expansions may con-
              tain  the  sequence  `%o' which will be replaced by the original
              string from the line.

              The kind of expansion to be tried is controlled by  the  substi-
              tute, glob and subst-globs-only styles.

              It is also possible to call _expand as a function, in which case
              the different modes may be selected with options: -s for substi-
              tute, -g for glob and -o for subst-globs-only.

       _expand_alias
              If  the word the cursor is on is an alias, it is expanded and no
              other completers are called.  The types of aliases which are  to
              be  expanded  can  be controlled with the styles regular, global
              and disabled.

              This function is also a bindable command, see the section `Bind-
              able Commands' below.

       _history
              Complete  words  from  the  shell's command  history.  This com-
              pleter can be controlled by the remove-all-dups, and sort styles
              as for the _history_complete_word bindable command, see the sec-
              tion `Bindable Commands' below and the section `Completion  Sys-
              tem Configuration' above.

       _ignored
              The  ignored-patterns  style  can  be  set to a list of patterns
              which are compared against possible completions;  matching  ones
              are  removed.   With  this  completer those matches can be rein-
              stated, as if no ignored-patterns style were set.  The completer
              actually generates its own list of matches; which completers are
              invoked is determined in the same way as for  the  _prefix  com-
              pleter.  The single-ignored style is also available as described
              above.

       _list  This completer allows the insertion of  matches  to  be  delayed
              until  completion is attempted a second time without the word on
              the line being changed.  On the first attempt, only the list  of
              matches  will  be shown.  It is affected by the styles condition
              and word, see  the  section  `Completion  System  Configuration'
              above.

       _match This  completer  is intended to be used after the _complete com-
              pleter.  It behaves similarly but the string on the command line
              may be a pattern to match against trial completions.  This gives
              the effect of the GLOB_COMPLETE option.

              Normally completion will be performed by taking the pattern from
              the  line,  inserting a `*' at the cursor position and comparing
              the resulting pattern with the possible  completions  generated.
              This  can  be  modified  with the match-original style described
              above.

              The generated matches will  be  offered  in  a  menu  completion
              unless  the  insert-unambiguous  style is set to `true'; see the
              description above for other options for this style.

              Note that matcher specifications defined globally or used by the
              completion  functions (the styles matcher-list and matcher) will
              not be used.

       _menu  This completer was written as simple example  function  to  show
              how  menu  completion  can be enabled in shell code. However, it
              has the notable effect of disabling menu selection which can  be
              useful  with  _generic  based  widgets. It should be used as the
              first completer in the list.  Note that this is  independent  of
              the  setting  of the MENU_COMPLETE option and does not work with
              the other menu completion widgets such as reverse-menu-complete,
              or accept-and-menu-complete.

       _oldlist
              This  completer  controls  how  the  standard completion widgets
              behave when there is an existing list of completions  which  may
              have  been  generated  by  a  special  completion  (i.e. a sepa-
              rately-bound completion command).  It allows the  ordinary  com-
              pletion  keys  to  continue  to use the list of completions thus
              generated, instead of producing a new list of  ordinary  contex-
              tual  completions.   It  should appear in the list of completers
              before any of the widgets which generate matches.  It  uses  two
              styles:  old-list and old-menu, see the section `Completion Sys-
              tem Configuration' above.

       _prefix
              This completer can be used to try  completion  with  the  suffix
              (everything after the cursor) ignored.  In other words, the suf-
              fix will not be considered to be part of the word  to  complete.
              The  effect is similar to the expand-or-complete-prefix command.

              The completer style is used to decide which other completers are
              to  be  called to generate matches.  If this style is unset, the
              list of completers set  for  the  current  context  is  used  --
              except,  of  course, the _prefix completer itself.  Furthermore,
              if this completer appears more than once in  the  list  of  com-
              pleters  only  those  completers  not  already tried by the last
              invocation of _prefix will be called.

              For example, consider this global completer style:

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

              Here, the _prefix completer tries normal completion but ignoring
              the  suffix.   If that doesn't generate any matches, and neither
              does the call to the _correct completer after it,  _prefix  will
              be called a second time and, now only trying correction with the
              suffix ignored.  On the second invocation the completer part  of
              the context appears as `foo'.

              To use _prefix as the last resort and try only normal completion
              when it is invoked:

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

              The add-space style is also respected.  If it is set  to  `true'
              then  _prefix  will insert a space between the matches generated
              (if any) and the suffix.

              Note that this completer is only useful if the  COMPLETE_IN_WORD
              option is set; otherwise, the cursor will be moved to the end of
              the current word before the completion code is called and  hence
              there will be no suffix.

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

              The expansion depends  on  the  array  style  user-expand  being
              defined  for  the current context; remember that the context for
              completers is less specific than that for contextual  completion
              as  the  full  context has not yet been determined.  Elements of
              the array may have one of the following forms:
              $hash   hash is the name of an associative array.  Note this  is
                     not  a  full  parameter  expression, merely a $, suitably
                     quoted to prevent immediate expansion,  followed  by  the
                     name  of  an  associative  array.  If the trial expansion
                     word matches a key in hash, the  resulting  expansion  is
                     the corresponding value.
              _func    _func  is  the name of a shell function whose name must
                     begin with _ but is not otherwise special to the  comple-
                     tion  system.  The function is called with the trial word
                     as an argument.  If the word is to be expanded, the func-
                     tion  should set the array reply to a list of expansions.
                     The return status 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,
              _expand_alias tries to complete the word to a  full  alias  name
              without  expanding  it.  It leaves the cursor directly after the
              completed word so that invoking  _expand_alias  once  more  will
              expand the now-complete alias name.

       _expand_word (^Xe)
              Performs expansion on the current word:  equivalent to the stan-
              dard expand-word  command,  but  using  the  _expand  completer.
              Before  calling  it, the function field of the context is set to
              `expand-word'.

       _generic
              This function is not defined  as  a  widget  and  not  bound  by
              default.   However,  it  can be used to define a widget and will
              then store the name of the widget in the function field  of  the
              context and call the completion system.  This allows custom com-
              pletion widgets with their own  set  of  style  settings  to  be
              defined  easily.   For example, to define a widget that performs
              normal completion and starts menu selection:

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

              Note in particular that the completer style may be set  for  the
              context in order to change the set of functions used to generate
              possible matches.  If _generic is called with  arguments,  those
              are  passed  through to _main_complete as the list of completers
              in place of those defined by the completer style.

       _history_complete_word (\e/)
              Complete words from the shell's command history. This  uses  the
              list, remove-all-dups, sort, and stop styles.

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

       _next_tags (^Xn)
              This command alters the set of matches used to that for the next
              tag,  or  set of tags, either as given by the tag-order style or
              as set by default; these matches would otherwise not  be  avail-
              able.   Successive  invocations of the command cycle through all
              possible sets of tags.

       _read_comp (^X^R)
              Prompt the user for a string, and use that to perform completion
              on  the  current  word.   There  are  two  possibilities for the
              string.  First, it can be a set  of  words  beginning  `_',  for
              example  `_files  -/', in which case the function with any argu-
              ments will be called to generate the  completions.   Unambiguous
              parts of the function name will be completed automatically (nor-
              mal completion is not available at this point) until a space  is
              typed.

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

              A  very  restricted  set  of  editing commands is available when
              reading the string:  `DEL' and `^H' delete the  last  character;
              `^U'  deletes  the  line,  and `^C' and `^G' abort the function,
              while `RET' accepts the completion.  Note  the  string  is  used
              verbatim  as  a  command  line,  so  arguments must be quoted in
              accordance with standard shell rules.

              Once a string has been read, the next call  to  _read_comp  will
              use  the existing string instead of reading a new one.  To force
              a new string to be read, call _read_comp with  a  numeric  argu-
              ment.

       _complete_debug (^X?)
              This widget performs ordinary completion, but captures in a tem-
              porary file a trace of the shell commands executed by  the  com-
              pletion  system.   Each completion attempt gets its own file.  A
              command to view each of these files is pushed  onto  the  editor
              buffer stack.

       _complete_help (^Xh)
              This  widget  displays  information about the context names, the
              tags, and the completion functions used when completing  at  the
              current  cursor position. If given a numeric argument other than
              1 (as in `ESC-2 ^Xh'), then the styles used and the contexts for
              which they are used will be shown, too.

              Note  that  the  information  about styles may be incomplete; it
              depends on the information available from the  completion  func-
              tions  called,  which  in  turn  is determined by the user's own
              styles and other settings.

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

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

              If the widget's name contains debug, for example if it  is  cre-
              ated as `zle -N _complete_debug_generic _complete_help_generic',
              it will read and execute the keystring for a generic  widget  as
              before, but then generate debugging information as done by _com-
              plete_debug for contextual completion.

              If the widget's  name  contains  noread,  it  will  not  read  a
              keystring  but  instead  arrange  that the next use of a generic
              widget run in the same shell will have the effect  as  described
              above.

              The    widget    works    by   setting   the   shell   parameter
              ZSH_TRACE_GENERIC_WIDGET which is read by  _generic.   Unsetting
              the parameter cancels any pending effect of the noread form.

              For example, after executing the following:

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

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

       _complete_tag (^Xt)
              This widget completes symbol tags created by the etags or  ctags
              programmes (note there is no connection with the completion sys-
              tem's tags) stored in a file TAGS, in the format used by  etags,
              or  tags,  in the format created by ctags.  It will look back up
              the path hierarchy for the first occurrence of either  file;  if
              both  exist,  the  file  TAGS is preferred.  You can specify the
              full path to a TAGS or tags file by setting the parameter $TAGS-
              FILE  or  $tagsfile  respectively.  The corresponding completion
              tags used are etags and vtags, after emacs and vi  respectively.



UTILITY FUNCTIONS

       Descriptions follow for utility functions that may be useful when writ-
       ing completion functions.  If functions are  installed  in  subdirecto-
       ries,  most of these reside in the Base subdirectory.  Like the example
       functions for commands in the distribution, the utility functions  gen-
       erating  matches  all follow the convention of returning status zero if
       they generated completions and  non-zero  if  no  matching  completions
       could be added.

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

       _all_labels [ -x ] [ -12VJ ] tag name descr [ command args ... ]
              This  is  a  convenient  interface  to  the _next_label function
              below, implementing the loop shown in the  _next_label  example.
              The  command  and  its  arguments  are  called  to  generate the
              matches.  The options stored in the parameter name will automat-
              ically  be  inserted  into the args passed to the command.  Nor-
              mally, they are put directly after the command, but  if  one  of
              the  args  is a single hyphen, they are inserted directly before
              that.  If the hyphen is the last argument, it  will  be  removed
              from  the  argument  list  before  the  command is called.  This
              allows _all_labels to be used in  almost  all  cases  where  the
              matches can be generated by a single call to the compadd builtin
              command or by a call to one of the utility functions.

              For example:

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

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

       _alternative [ -C name ] spec ...
              This function is useful in simple cases where multiple tags  are
              available.   Essentially  it  implements  a  loop  like  the one
              described for the _tags function below.

              The tags to use and the action to perform if a tag is  requested
              are   described   using   the  specs  which  are  of  the  form:
              `tag:descr:action'.  The tags are offered using _tags and if the
              tag is requested, the action is executed with the given descrip-
              tion descr.  The actions are those accepted  by  the  _arguments
              function  (described  below), excluding the `->state' and `=...'
              forms.

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

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

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

              Like  _arguments,  this 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.

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

       _arguments [ -nswWACRS ] [ -O name ] [ -M matchspec ] [ : ] spec ...
              This  function  can be used to give a complete specification for
              completion for a command whose arguments  follow  standard  UNIX
              option  and  argument  conventions.  The following forms specify
              individual sets of options and arguments;  to  avoid  ambiguity,
              these  may be separated from the options to _arguments itself by
              a single colon.  Options to _arguments itself must be  in  sepa-
              rate words, i.e. -s -w, not -sw.

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

              n:message:action
              n::message:action
                     This describes the n'th  normal  argument.   The  message
                     will  be  printed  above  the  matches  generated and the
                     action indicates what can be completed in  this  position
                     (see  below).  If there are two colons before the message
                     the argument is optional.  If the message  contains  only
                     white  space,  nothing  will be printed above the matches
                     unless the action adds an explanation string itself.

              :message:action
              ::message:action
                     Similar, but describes the next argument, whatever number
                     that  happens  to  be.  If all arguments are specified in
                     this form in the correct order the numbers  are  unneces-
                     sary.

              *:message:action
              *::message:action
              *:::message:action
                     This  describes  how  arguments (usually non-option argu-
                     ments, those not beginning with - or +) are  to  be  com-
                     pleted  when neither of the first two forms was provided.
                     Any number of arguments can be completed in this fashion.

                     With  two  colons  before  the message, the words special
                     array and the CURRENT special parameter are  modified  to
                     refer  only  to  the  normal arguments when the action is
                     executed or evaluated.  With three colons before the mes-
                     sage  they are modified to refer only to the normal argu-
                     ments covered by this description.

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

                     By default, options are multi-character name, one `-word'
                     per  option.   With -s, options may be single characters,
                     with more than one option per word, although words start-
                     ing  with two hyphens, such as `--prefix', are still con-
                     sidered complete option  names.   This  is  suitable  for
                     standard GNU options.

                     The  combination  of  -s  with  -w  allows  single-letter
                     options to be combined in a single word even  if  one  or
                     more  of  the options take arguments.  For example, if -a
                     takes an argument, with no -s `-ab' is  considered  as  a
                     single  (unhandled) option; with -s -ab is an option with
                     the argument `b'; with both -s and -w,  -ab  may  be  the
                     option -a and the option -b with arguments still to come.

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

                     The  following  forms  are available for the initial opt-
                     spec, whether or not the option has arguments.

                     *optspec
                            Here optspec is one of the remaining forms  below.
                            This   indicates  the  following  optspec  may  be
                            repeated.  Otherwise if the  corresponding  option
                            is already present on the command line to the left
                            of the cursor it will not be offered again.

                     -optname
                     +optname
                            In the simplest  form  the  optspec  is  just  the
                            option name beginning with a minus or a plus sign,
                            such as `-foo'.  The first argument for the option
                            (if  any)  must follow as a separate word directly
                            after the option.

                            Either of `-+optname' and `+-optname' can be  used
                            to  specify  that  -optname  and +optname are both
                            valid.

                            In all the remaining forms, the leading `-' may be
                            replaced by or paired with `+' in this way.

                     -optname-
                            The   first  argument  of  the  option  must  come
                            directly after the option name in the  same  word.
                            For  example,  `-foo-:...' specifies that the com-
                            pleted  option  and  argument   will   look   like
                            `-fooarg'.

                     -optname+
                            The  first  argument  may appear immediately after
                            optname in the same word, or may appear as a sepa-
                            rate   word   after   the  option.   For  example,
                            `-foo+:...' specifies that  the  completed  option
                            and  argument  will  look like either `-fooarg' or
                            `-foo arg'.

                     -optname=
                            The argument may appear as the next  word,  or  in
                            same  word  as the option name provided that it is
                            separated from it by an equals sign,  for  example
                            `-foo=arg' or `-foo arg'.

                     -optname=-
                            The  argument  to  the option must appear after an
                            equals sign in the same word, and may not be given
                            in the next argument.

                     optspec[explanation]
                            An  explanation  string  may be appended to any of
                            the preceding forms of optspec by enclosing it  in
                            brackets, as in `-q[query operation]'.

                            The  verbose  style  is used to decide whether the
                            explanation strings are displayed with the  option
                            in a completion listing.

                            If  no  bracketed  explanation string is given but
                            the auto-description style is  set  and  only  one
                            argument  is described for this optspec, the value
                            of the style is displayed, with any appearance  of
                            the sequence `%d' in it replaced by the message of
                            the first optarg that  follows  the  optspec;  see
                            below.

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

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

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

                     This group may be repeated for options which take  multi-
                     ple  arguments.   In  other words, :message1:action1:mes-
                     sage2:action2 specifies that the option takes  two  argu-
                     ments.

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

                     Multiple  colons are treated as for the `*:...' forms for
                     ordinary arguments:  when the message is preceded by  two
                     colons,  the  words special array and the CURRENT special
                     parameter are modified during the execution or evaluation
                     of  the  action  to  refer  only  to  the words after the
                     option.  When preceded by three colons, they are modified
                     to refer only to the words covered by this description.

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

       Each of the forms above may be preceded by a  list  in  parentheses  of
       option  names and argument numbers.  If the given option is on the com-
       mand line, the options and arguments indicated in parentheses will  not
       be  offered.   For  example,  `(-two  -three  1)-one:...' completes the
       option `-one'; if this appears on the command line,  the  options  -two
       and  -three and the first ordinary argument will not be completed after
       it.  `(-foo):...' specifies an ordinary argument completion; -foo  will
       not be completed if that argument is already present.

       Other items may appear in the list of excluded options to indicate var-
       ious other items that should not be applied when the current specifica-
       tion is matched: a single star (*) for the rest arguments (i.e. a spec-
       ification  of  the  form  `*:...');  a  colon  (:)   for   all   normal
       (non-option-)  arguments;  and a hyphen (-) for all options.  For exam-
       ple, if `(*)' appears before an option and the option  appears  on  the
       command line, the list of remaining arguments (those shown in the above
       table beginning with `*:') will not be completed.

       To aid in reuse of specifications, it is possible to precede any of the
       forms  above  with  `!';  then  the  form  will no longer be completed,
       although if the option or argument appears on  the  command  line  they
       will be skipped as normal.  The main use for this is when the arguments
       are given by an array, and _arguments is  called  repeatedly  for  more
       specific  contexts:  on  the first call `_arguments $global_options' is
       used, and on subsequent calls `_arguments !$^global_options'.

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

       The forms for action are as follows.

         (single unquoted space)
              This is useful where an argument is required but it is not  pos-
              sible or desirable to generate matches for it.  The message will
              be displayed but no completions listed.  Note that even in  this
              case  the colon at the end of the message is needed; it may only
              be omitted when neither a message nor an action is given.

       (item1 item2 ...)
              One of a list of possible matches, for example:

                     :foo:(foo bar baz)

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

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

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

       ->string
              In this form, _arguments processes the arguments and options and
              then returns control to the calling function with parameters set
              to  indicate  the state of processing; the calling function then
              makes its own  arrangements  for  generating  completions.   For
              example,  functions  that implement a state machine can use this
              type of action.

              Where _arguments encounters a  `->string',  it  will  strip  all
              leading  and  trailing  whitespace from string and set the array
              state to the set of all stringss for which an action  is  to  be
              performed.

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

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

              A  function calling _arguments with at least one action contain-
              ing a `->string' must therefore declare appropriate local param-
              eters:

                     local context state line
                     typeset -A opt_args

              to prevent _arguments from altering the global environment.

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

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

              This is most useful with one of the specifiers that restrict the
              words on the command line on which the action is to operate (the
              two- and three-colon forms above).  One particular use  is  when
              an  action itself causes _arguments on a restricted range; it is
              necessary to use this trick to  insert  an  appropriate  command
              name into the range for the second call to _arguments to be able
              to parse the line.

        word...
       word...
              This covers all forms other than those  above.   If  the  action
              starts with a space, the remaining list of words will be invoked
              unchanged.

              Otherwise it will be invoked  with  some  extra  strings  placed
              after  the first word; these are to be passed down as options to
              the compadd builtin.  They ensure that the  state  specified  by
              _arguments,  in particular the descriptions of options and argu-
              ments, is correctly passed to  the  completion  command.   These
              additional  arguments are taken from the array parameter `expl';
              this will be set up before executing the action and hence may be
              referred  to  inside  it,  typically in an expansion of the form
              `$expl[@]' which preserves empty elements of the array.

       During the performance of the action the array `line' will  be  set  to
       the  command  name and normal arguments from the command line, i.e. the
       words from the command line excluding all options and their  arguments.
       Options  are  stored  in  the  associative array `opt_args' with option
       names as keys and their arguments as the values.  For options that have
       more  than  one  argument  these  are given as one string, separated by
       colons.  All colons in the original arguments are preceded  with  back-
       slashes.

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

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

       It is possible to specify multiple sets of options and  arguments  with
       the  sets  separated  by single hyphens.  The specifications before the
       first hyphen (if any) are shared by all the remaining sets.  The  first
       word in every other set provides a name for the set which may appear in
       exclusion lists in specifications, either alone or before  one  of  the
       possible  values  described  above.   In  the  second case a `-' should
       appear between this name and the remainder.

       For example:

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

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

       If the name given for one of the mutually exclusive sets is of the form
       `(name)' then only one value from each set will ever be completed; more
       formally, all specifications are mutually exclusive to all other speci-
       fications  in  the same set.  This is useful for defining multiple sets
       of options which are mutually exclusive and in which  the  options  are
       aliases for each other.  For example:

              _arguments \
                  -a -b \
                - '(compress)' \
                  {-c,--compress}'[compress]' \
                - '(uncompress)' \
                  {-d,--decompress}'[decompress]'

       As  the  completion  code  has to parse the command line separately for
       each set this form of argument is slow and should  only  be  used  when
       necessary.   A useful alternative is often an option specification with
       rest-arguments (as in `-foo:*:...'); here the option -foo  swallows  up
       all remaining arguments as described by the optarg definitions.

       The  options -S and -A are available to simplify the specifications for
       commands with standard option parsing.  With -S, no option will be com-
       pleted  after  a  `--'  appearing on its own on the line; this argument
       will otherwise be ignored; hence in the line

              foobar -a -- -b

       the `-a' is considered an option but the `-b' is  considered  an  argu-
       ment, while the `--' is considered to be neither.

       With  -A, no options will be completed after the first non-option argu-
       ment on the line.  The -A must be followed by a  pattern  matching  all
       strings  which  are not to be taken as arguments.  For example, to make
       _arguments stop completing options after the first normal argument, but
       ignoring  all  strings  starting  with  a  hyphen  even if they are not
       described by one of the optspecs, the form is `-A "-*"'.

       The option `-O name' specifies the name of an array whose elements will
       be  passed  as  arguments  to functions called to execute actions.  For
       example, this can be used to pass the same set of options for the  com-
       padd builtin to all actions.

       The  option  `-M  spec' sets a match specification to use to completion
       option names and values.  It must  appear  before  the  first  argument
       specification.   The  default is `r:|[_-]=* r:|=*': this allows partial
       word completion after `_' and `-', for example `-f-b' can be  completed
       to `-foo-bar'.

       The  option  -C tells _arguments to modify the curcontext parameter for
       an action of the form `->state'.  This is the standard  parameter  used
       to  keep  track  of  the current context.  Here it (and not the context
       array) should be made local to the calling function  to  avoid  passing
       back  the modified value and should be initialised to the current value
       at the start of the function:

              local curcontext="$curcontext"

       This is useful where it is not possible for multiple states to be valid
       together.

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

       In addition to options, `_arguments --' will try to deduce the types of
       arguments available for options when the form `--opt=val' is valid.  It
       is also possible to provide hints by examining the  help  text  of  the
       command  and  adding  specifiers  of the form `pattern:message:action';
       note that normal _arguments specifiers are not used.   The  pattern  is
       matched against the help text for an option, and if it matches the mes-
       sage and action are used as for other argument specifiers.   For  exam-
       ple:

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

       Here, `yes' and `no' will be completed as the argument of options whose
       description ends in a star; file names will be  completed  for  options
       that  contain the substring `=FILE' in the description; and directories
       will be completed for options  whose  description  contains  `=DIR'  or
       `=PATH'.   The  last  three  are in fact the default and so need not be
       given explicitly, although it is possible to override the use of  these
       patterns.  A typical help text which uses this feature is:

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

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

       Note also that _arguments tries to find out automatically if the  argu-
       ment  for  an  option is optional.  This can be specified explicitly by
       doubling the colon before the message.

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

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

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

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

       The  `_arguments  --' form can also be followed by the option `-s pair'
       to describe option aliases.  Each pair consists  of  a  pattern  and  a
       replacement.  For example, some configure-scripts describe options only
       as `--enable-foo', but also accept `--disable-foo'.  To  allow  comple-
       tion of the second form:

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

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

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

       This  describes three options: `-l', `-format', and `-copy'.  The first
       takes one argument described as `left border' for which  no  completion
       will  be  offered  because  of the empty action.  Its argument may come
       directly after the `-l' or it may be given as  the  next  word  on  the
       line.

       The  `-format' option takes one argument in the next word, described as
       `paper size' for which only the strings `letter' and `A4' will be  com-
       pleted.

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

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

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

              Example:

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

       _call_function return name [ args ... ]
              If a function name exists, it is called with the arguments args.
              The  return  argument gives the name of a parameter in which the
              return status from the function name 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 tag string ...
              This function provides a mechanism for the user to override  the
              use  of an external command.  It looks up the command style with
              the supplied tag.  If the style is set, its value is used as the
              command to execute.  The strings from the call to _call_program,
              or from the style if set, are concatenated with  spaces  between
              them  and  the resulting string is evaluated.  The return status
              is the return status of the command called.

       _combination [ -s pattern ] tag style spec ... field opts ...
              This function is used to complete combinations of  values,   for
              example  pairs  of  hostnames and usernames.  The style argument
              gives the style which defines the pairs; it is looked  up  in  a
              context with the tag specified.

              The style name consists of field names separated by hyphens, for
              example `users-hosts-ports'.  For each  field  for  a  value  is
              already known, a spec of the form `field=pattern' is given.  For
              example, if the command line so far specifies a user `pws',  the
              argument `users=pws' should appear.

              The  next  argument  with no equals sign is taken as the name of
              the field for which completions should be generated  (presumably
              not one of the fields for which the value is known).

              The matches generated will be taken from the value of the style.
              These should contain the possible values for the combinations in
              the  appropriate  order  (users,  hosts,  ports  in  the example
              above).  The different  fields  the  values  for  the  different
              fields  are  separated  by colons.  This can be altered with the
              option -s to _combination which specifies a pattern.   Typically
              this  is  a  character  class, as for example `-s "[:@]"' in the
              case of the users-hosts style.    Each `field=pattern'  specifi-
              cation  restricts the completions which apply to elements of the
              style with appropriately matching fields.

              If no style with the given name is defined for the given tag, or
              if  none  of  the strings in style's value match, but a function
              name of the required field preceded by an underscore is defined,
              that function will be called to generate the matches.  For exam-
              ple, if there is no `users-hosts-ports' or no matching  hostname
              when  a  host  is required, the function `_hosts' will automati-
              cally be called.

              If the same name is used for more than one field,  in  both  the
              `field=pattern'  and  the  argument  that  gives the name of the
              field to be completed, the number of the  field  (starting  with
              one)  may  be  given after the fieldname, separated from it by a
              colon.

              All arguments after the required field name are passed  to  com-
              padd  when  generating  matches  from the style value, or to the
              functions for the fields if they are called.

       _describe [ -oO | -t tag ] descr name1 [ name2 ] opts ... -- ...
              This function associates completions with descriptions.   Multi-
              ple  groups  separated  by  -- can be supplied, potentially with
              different completion options opts.

              The descr is taken as a string to display above the  matches  if
              the  format style for the descriptions tag is set.  This is fol-
              lowed by one or two names of arrays followed by options to  pass
              to  compadd.   The first array contains the possible completions
              with their descriptions in  the  form  `completion:description'.
              Any  literal  colons  in  completion must be quoted with a back-
              slash.  If a second array is given, it should have the same num-
              ber  of  elements  as  the first; in this case the corresponding
              elements are added as possible completions instead of  the  com-
              pletion  strings from the first array.  The completion list will
              retain the descriptions from the first array.  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'.

              If  selected  by  the  list-grouped style, strings with the same
              description will appear together in the list.

              _describe uses the _all_labels function to generate the matches,
              so it does not need to appear inside a loop over tag labels.

       _description [ -x ] [ -12VJ ] tag name descr [ spec ... ]
              This function is not to be confused with the previous one; it is
              used as a helper function for creating options to  compadd.   It
              is  buried  inside many of the higher level completion functions
              and so often does not need to be called directly.

              The styles listed below are tested in the current context  using
              the  given  tag.  The resulting options for compadd are put into
              the array named name (this is  traditionally  `expl',  but  this
              convention  is  not  enforced).   The description for the corre-
              sponding set of matches is passed to the function in descr.

              The styles tested are: format, hidden, matcher, ignored-patterns
              and  group-name.  The format style is first tested for the given
              tag and then for the descriptions tag if  no  value  was  found,
              while  the  remainder  are  only tested for the tag given as the
              first argument.  The function also calls _setup which tests some
              more styles.

              The  string  returned by the format style (if any) will be modi-
              fied so that the sequence `%d' is replaced by the descr given as
              the  third argument without any leading or trailing white space.
              If, after removing the white  space,  the  descr  is  the  empty
              string,  the  format  style will not be used and the options put
              into the name array will not contain an explanation string to be
              displayed above the matches.

              If  _description  is  called with more than three arguments, the
              additional specs should be of the form `char:str'.  These supply
              escape sequence replacements for the format style: every appear-
              ance of `%char' will be replaced by string.

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

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

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

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

              Note the use of the parameter expl, the hyphen, and the list  of
              matches.  Almost all calls to compadd within the completion sys-
              tem use a  similar  format;  this  ensures  that  user-specified
              styles are correctly passed down to the builtins which implement
              the internals of completion.

       _dispatch context string ...
              This sets the current context to context and looks  for  comple-
              tion  functions  to  handle  this context by hunting through the
              list of command names or special contexts  (as  described  above
              for compdef) given as string ....  The first completion function
              to be defined for one of the contexts in the  list  is  used  to
              generate  matches.   Typically,  the last string is -default- to
              cause the function for default completion to be used as a  fall-
              back.

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

       _files The function _files calls _path_files with all the arguments  it
              was  passed  except for -g and -/.  The use of these two options
              depends on the setting of the  file-patterns style.

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

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

                     compdef _gnu_generic foo bar

              after the call to compinit.

              The completion system as supplied is conservative in its use  of
              this  function,  since  it  is  important to be sure the command
              understands the option `--help'.

       _guard [ options ] pattern descr
              This function is intended to be used in the action for the spec-
              ifications  passed  to  _arguments  and  similar  functions.  It
              returns immediately with a non-zero return status if the  string
              to  be  completed  does  not  match the pattern.  If the pattern
              matches, the descr is displayed; the function then returns  sta-
              tus  zero  if the word to complete is not empty, non-zero other-
              wise.

              The pattern may be preceded by any of the options understood  by
              compadd  that  are passed down from _description, namely -M, -J,
              -V, -1, -2, -n, -F  and  -X.   All  of  these  options  will  be
              ignored.   This  fits  in conveniently with the argument-passing
              conventions of actions for _arguments.

              As an example, consider a command  taking  the  options  -n  and
              -none,  where -n must be followed by a numeric value in the same
              word.  By using:

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

              _arguments can be made to  both  display  the  message  `numeric
              value'  and  complete  options  after `-n<TAB>'.  If the `-n' is
              already followed by one or more digits (the  pattern  passed  to
              _guard)  only the message will be displayed; if the `-n' is fol-
              lowed by another character, only options are completed.

       _message [ -r12 ] [ -VJ group ] descr
       _message -e [ tag ] descr
              The descr is used in the same way as the third argument  to  the
              _description  function,  except  that  the resulting string will
              always be shown whether or not matches were generated.  This  is
              useful  for displaying a help message in places where no comple-
              tions can be generated.

              The format style is examined with the messages  tag  to  find  a
              message;  the usual tag, descriptions, is used only if the style
              is not set with the former.

              If the -r option is given, no style is used; the descr is  taken
              literally  as  the  string to display.  This is most useful when
              the descr comes from a pre-processed argument list which already
              contains an expanded description.

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

              The second form gives a description for completions with the tag
              tag  to be shown even if there are no matches for that tag.  The
              tag can be omitted and if so the tag is taken from the parameter
              $curtag;  this  is maintained by the completion system and so is
              usually correct.

       _multi_parts sep array
              The argument sep is a separator character.   The  array  may  be
              either  the name of an array parameter or a literal array in the
              form `(foo bar)', a parenthesised list  of  words  separated  by
              whitespace.   The  possible completions are the strings from the
              array.  However, each chunk delimited by sep will  be  completed
              separately.  For example, the _tar function uses `_multi_parts /
              patharray' to complete partial file paths from the  given  array
              of complete file paths.

              The  -i option causes _multi_parts to insert a unique match even
              if that requires multiple separators to be  inserted.   This  is
              not  usually  the expected behaviour with filenames, but certain
              other types of completion, for example those with a fixed set of
              possibilities, may be more suited to this form.

              Like  other  utility  functions, this function accepts the `-V',
              `-J', `-1', `-2', `-n', `-f',  `-X',  `-M',  `-P',  `-S',  `-r',
              `-R', and `-q' options and passes them to the compadd builtin.

       _next_label [ -x ] [ -12VJ ] tag name descr [ options ... ]
              This  function  is used to implement the loop over different tag
              labels for a particular tag as described above for the tag-order
              style.   On each call it checks to see if there are any more tag
              labels; if there is it returns status zero, otherwise  non-zero.
              As  this  function  requires  a  current  tag to be set, it must
              always follow a call to _tags or _requested.

              The -x12VJ options and the first three arguments are  passed  to
              the  _description  function.   Where appropriate the tag will be
              replaced by a tag label in this call.  Any description given  in
              the  tag-order  style  is  preferred  to  the  descr  passed  to
              _next_label.

              The options given after the descr are set in the parameter given
              by name, and hence are to be passed to compadd or whatever func-
              tion is called to add the matches.

              Here is a typical use of this function for  the  tag  foo.   The
              call to _requested determines if tag foo is required at all; the
              loop over _next_label handles any labels defined for the tag  in
              the tag-order style.

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

       _normal
              This  is  the standard function called to handle completion out-
              side any special -context-.  It is called both to  complete  the
              command  word and also the arguments for a command.  In the sec-
              ond case, _normal looks for a special completion for  that  com-
              mand,  and  if  there  is  none  it  uses the completion for the
              -default- context.

              A second use is to reexamine the command line specified  by  the
              $words  array  and  the $CURRENT parameter after those have been
              modified.  For example, the  function  _precommand,  which  com-
              pletes  after  pre-command specifiers such as nohup, removes the
              first word from the words array, decrements the CURRENT  parame-
              ter,  then  calls  _normal again.  The effect is that `nohup cmd
              ...' is treated in the same way as `cmd ...'.

              If the command name matches one of the patterns given by one  of
              the  options  -p  or -P to compdef, the corresponding completion
              function is called and then the parameter _compskip is  checked.
              If  it  is set completion is terminated at that point even if no
              matches have been found.  This is the  same  effect  as  in  the
              -first- context.

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

       _options_set and _options_unset
              These functions complete only set or  unset  options,  with  the
              same matching specification used in the _options function.

              Note  that  you  need to uncomment a few lines in the _main_com-
              plete function for these functions to work properly.  The  lines
              in  question  are  used  to  store the option settings in effect
              before the completion widget locally sets the options it  needs.
              Hence  these  functions are not generally used by the completion
              system.

       _parameters
              This is used to complete the names of shell parameters.

              The option `-g pattern'  limits  the  completion  to  parameters
              whose type matches the pattern.  The type of a parameter is that
              shown by `print ${(t)param}', hence judicious use of `*' in pat-
              tern is probably necessary.

              All other arguments are passed to the compadd builtin.

       _path_files
              This  function  is used throughout the completion system to com-
              plete filenames.  It allows completion of  partial  paths.   For
              example,   the   string   `/u/i/s/sig'   may   be  completed  to
              `/usr/include/sys/signal.h'.

              The options accepted by both _path_files and _files are:

              -f     Complete all filenames.  This is the default.

              -/     Specifies that only directories should be completed.

              -g pattern
                     Specifies that only files matching the pattern should  be
                     completed.

              -W paths
                     Specifies  path  prefixes that are to be prepended to the
                     string from the command line to  generate  the  filenames
                     but  that should not be inserted as completions nor shown
                     in completion listings.  Here, paths may be the  name  of
                     an  array  parameter, a literal list of paths enclosed in
                     parentheses or an absolute pathname.

              -F ignored-files
                     This behaves as for the corresponding option to the  com-
                     padd  builtin.   It gives direct control over which file-
                     names should be ignored.  If the option is  not  present,
                     the ignored-patterns style is used.

              Both  _path_files  and  _files also accept the following options
              which are passed to compadd: `-J', `-V', `-1', `-2', `-n', `-X',
              `-M', `-P', `-S', `-q', `-r', and `-R'.

              Finally,  the  _path_files  function   uses  the  styles expand,
              ambiguous, special-dirs, list-suffixes and  file-sort  described
              above.

       _pick_variant [ -c command ] [ -r name ] label=pattern ... label [ args
       ... ]
              This  function is used to resolve situations where a single com-
              mand name requires  more  than  one  type  of  handling,  either
              because  it has more than one variant or because there is a name
              clash between two different commands.

              The command to run is taken from the first element of the  array
              words  unless this is overridden by the option -c.  This command
              is run and its output is compared with  a  series  of  patterns.
              Arguments  to  be  passed to the command can be specified at the
              end after all the other arguments.  The patterns to try in order
              are given by the arguments label=pattern; if the output of `com-
              mand args ...' contains pattern, then label is selected  as  the
              label  for  the command variant.  If none of the patterns match,
              the final command label is selected and status 1 is returned.

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

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

       _regex_arguments name spec ...
              This function generates a completion function name which matches
              the  specifications  spec  ...,  a set of regular expressions as
              described below.  After running _regex_arguments,  the  function
              name should be called as a normal completion function.  The pat-
              tern to be matched is given by the contents of the  words  array
              up  to  the  current  cursor  position joined together with null
              characters; no quotation is applied.

              The arguments are grouped as sets of alternatives  separated  by
              `|',  which  are  tried  one  after the other until one matches.
              Each alternative consists of a one or more specifications  which
              are  tried  left  to  right,  with  each  pattern  matched being
              stripped in turn from the command line being tested,  until  all
              of  the  group  succeeds or until one fails; in the latter case,
              the next alternative is tried.  This structure can  be  repeated
              to  arbitrary depth by using parentheses; matching proceeds from
              inside to outside.

              A special procedure is applied  if  no  test  succeeds  but  the
              remaining command line string contains no null character (imply-
              ing the remaining word is the one for which completions  are  to
              be  generated).   The  completion  target  is  restricted to the
              remaining word and any actions for  the  corresponding  patterns
              are  executed.   In this case, nothing is stripped from the com-
              mand line string.  The order of evaluation of the actions can be
              determined by the tag-order style; the various formats supported
              by _alternative can be used in action.  The descr  is  used  for
              setting up the array parameter expl.

              Specification  arguments  take  one of following forms, in which
              metacharacters such as `(', `)', `#' and `|' should be quoted.

              /pattern/ [%lookahead%] [-guard] [:tag:descr:action]
                     This is a single primitive component.  The function tests
                     whether  the  combined  pattern  `(#b)((#B)pattern)looka-
                     head*' matches the command line string.  If  so,  `guard'
                     is  evaluated and its return status is examined to deter-
                     mine if the test has succeeded.  The pattern string  `[]'
                     is  guaranteed  never  to  match.   The  lookahead is not
                     stripped from the command line before the next pattern is
                     examined.

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

                     A component is used as follows: pattern is tested to  see
                     if  the component already exists on the command line.  If
                     it does, any following  specifications  are  examined  to
                     find  something  to  complete.  If a component is reached
                     but no such pattern exists yet on the command  line,  the
                     string  containing the action is used to generate matches
                     to insert at that point.

              /pattern/+ [%lookahead%] [-guard] [:tag:descr:action]
                     This is similar to `/pattern/ ...' but the left  part  of
                     the command line string (i.e. the part already matched by
                     previous patterns) is also considered part of the comple-
                     tion target.

              /pattern/- [%lookahead%] [-guard] [:tag:descr:action]
                     This is similar to `/pattern/ ...' but the actions of the
                     current and previously matched patterns are ignored  even
                     if the following `pattern' matches the empty string.

              ( spec )
                     Parentheses may be used to groups specs; note each paren-
                     thesis is a single argument to _regex_arguments.

              spec # This allows any number of repetitions of spec.

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

              spec | spec
                     Either of the two specs can be matched.

              The  function  _regex_words  can be used as a helper function to
              generate matches for a set of alternative  words  possibly  with
              their own arguments as a command line argument.

              Examples:

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

              This  generates  a  function _tst that completes aaa as its only
              argument.  The tag and description  for  the  action  have  been
              omitted for brevity (this works but is not recommended in normal
              use).  The first component matches the command  word,  which  is
              arbitrary; the second matches  any argument.  As the argument is
              also arbitrary, any following component would not depend on  aaa
              being present.

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

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

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

              In  this  example, an indefinite number of command arguments may
              be completed.  Odd arguments are completed as aaa and even argu-
              ments  as  bbb.   Completion fails unless the set of aaa and bbb
              arguments before the current one is matched correctly.

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

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


       _regex_words tag description spec ...
              This  function  can  be  used  to  generate  arguments  for  the
              _regex_arguments  command  which  may  be  inserted at any point
              where a set of rules is expected.  The tag and description  give
              a  standard  tag  and description pertaining to the current con-
              text.  Each spec contains two or three arguments separated by  a
              colon: note that there is no leading colon in this case.

              Each  spec  gives one of a set of words that may be completed at
              this point, together with arguments.  It is thus roughly equiva-
              lent  to the _arguments function when used in normal (non-regex)
              completion.

              The part of the spec before the first colon is the  word  to  be
              completed.   This  may  contain a *; the entire word, before and
              after the * is completed, but only the  text  before  the  *  is
              required  for  the  context to be matched, so that further argu-
              ments may be completed after the abbreviated form.

              The second part of spec is a description for the word being com-
              pleted.

              The  optional third part of the spec describes how words follow-
              ing the one being completed are themselves to be completed.   It
              will be evaluated in order to avoid problems with quoting.  This
              means that typically it contains a reference to  an  array  con-
              taining previously generated regex arguments.

              The  option  -t term specifies a terminator for the word instead
              of the usual space.  This is handled as an auto-removable suffix
              in the manner of the option -s sep to _values.

              The  result  of  the processing by _regex_words is placed in the
              array reply, which should be made local to the calling function.
              If the set of words and arguments may be matched repeatedly, a #
              should be appended to the generated array at that point.

              For example:

                     local -a reply
                     _regex_words mydb-commands 'mydb commands' \
                       'add:add an entry to mydb:$mydb_add_cmds' \
                       'show:show entries in mydb'
                     _regex_arguments _mydb "$reply[@]"
                     _mydb "$@"

              This shows a completion function for a command mydb which  takes
              two  command  arguments, add and show.  show takes no arguments,
              while the arguments for add have already  been  prepared  in  an
              array  mydb_add_cmds,  quite  possibly  by  a  previous  call to
              _regex_words.

       _requested [ -x ] [ -12VJ ] tag [ name descr [ command args ... ] ]
              This function is called to decide whether a tag  already  regis-
              tered  by  a call to _tags (see below) has been requested by the
              user and hence  completion  should  be  performed  for  it.   It
              returns  status zero if the tag is requested and non-zero other-
              wise.  The function is typically used as part  of  a  loop  over
              different tags as follows:

                     _tags foo bar baz
                     while _tags; do
                       if _requested foo; then
                         ... # perform completion for foo
                       fi
                       ... # test the tags bar and baz in the same way
                       ... # exit loop if matches were generated
                     done

              Note  that  the  test  for whether matches were generated is not
              performed until the end of the _tags loop.  This is so that  the
              user  can set the tag-order style to specify a set of tags to be
              completed at the same time.

              If name and descr are given, _requested calls  the  _description
              function  with  these arguments together with the options passed
              to _requested.

              If command is given, the _all_labels  function  will  be  called
              immediately with the same arguments.  In simple cases this makes
              it possible to perform the test for the tag and the matching  in
              one go.  For example:

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

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

       _retrieve_cache cache_identifier
              This function retrieves completion  information  from  the  file
              given  by  cache_identifier,  stored in a directory specified by
              the cache-path  style  which  defaults  to  ~/.zcompcache.   The
              return status is zero if retrieval was successful.  It will only
              attempt retrieval if the use-cache style is set, so you can call
              this  function without worrying about whether the user wanted to
              use the caching layer.

              See _store_cache below for more details.

       _sep_parts
              This function is passed alternating  arrays  and  separators  as
              arguments.   The arrays specify completions for parts of strings
              to be separated by the separators.  The arrays may be the  names
              of  array  parameters  or a quoted list of words in parentheses.
              For  example,  with  the  array  `hosts=(ftp  news)'  the   call
              `_sep_parts  '(foo  bar)' @ hosts' will complete the string  `f'
              to `foo' and the string `b@n' to `bar@news'.

              This function accepts the  compadd  options  `-V',  `-J',  `-1',
              `-2',  `-n',  `-X',  `-M',  `-P', `-S', `-r', `-R', and `-q' and
              passes them on to the compadd builtin used to add the matches.

       _setup tag [ group ]
              This function sets up the special parameters used by the comple-
              tion  system  appropriately for the tag given as the first argu-
              ment.    It   uses   the   styles   list-colors,    list-packed,
              list-rows-first, last-prompt, accept-exact, menu and force-list.

              The optional group supplies the name of the group in  which  the
              matches  will be placed.  If it is not given, the tag is used as
              the group name.

              This function is  called  automatically  from  _description  and
              hence is not normally called explicitly.

       _store_cache cache_identifier params ...
              This function, together with _retrieve_cache and _cache_invalid,
              implements a caching layer which can be used in  any  completion
              function.   Data  obtained  by  costly  operations are stored in
              parameters; this function then dumps the values of those parame-
              ters  to  a  file.   The data can then be retrieved quickly from
              that file via _retrieve_cache, even in  different  instances  of
              the shell.

              The cache_identifier specifies the file which the data should be
              dumped to.  The file is stored in a directory specified  by  the
              cache-path style which defaults to ~/.zcompcache.  The remaining
              params arguments are the parameters to dump to the file.

              The return status is zero if storage was successful.  The  func-
              tion will only attempt storage if the use-cache style is set, so
              you can call this function without worrying  about  whether  the
              user wanted to use the caching layer.

              The  completion  function may avoid calling _retrieve_cache when
              it already has the  completion  data  available  as  parameters.
              However,  in  that  case  it should call _cache_invalid to check
              whether the data in the parameters and in the  cache  are  still
              valid.

              See  the  _perl_modules completion function for a simple example
              of the usage of the caching layer.

       _tags [ [ -C name ] tags ... ]
              If called with arguments, these are taken to  be  the  names  of
              tags  valid  for completions in the current context.  These tags
              are stored internally and sorted by using the tag-order style.

              Next, _tags is called repeatedly without arguments from the same
              completion  function.  This successively selects the first, sec-
              ond, etc. set of tags requested by the user.  The return  status
              is  zero  if  at least one of the tags is requested and non-zero
              otherwise.  To test if a particular tag  is  to  be  tried,  the
              _requested function should be called (see above).

              If  `-C  name' is given, name is temporarily stored in the argu-
              ment field (the fifth) of the context in the curcontext  parame-
              ter  during  the  call  to _tags; the field is restored on exit.
              This allows _tags to use a more specific context without  having
              to change and reset the curcontext parameter (which has the same
              effect).

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

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

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

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

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

              All other arguments describe the possible values and their argu-
              ments  in the same format used for the description of options by
              the _arguments function (see above).  The only  differences  are
              that  no minus or plus sign is required at the beginning, values
              can have only one argument, and the forms  of  action  beginning
              with an equal sign are not supported.

              The  character  separating  a value from its argument can be set
              using the option -S (like -s, followed by the character  to  use
              as  the  separator in the next argument).  By default the equals
              sign will be used as the separator between values and arguments.

              Example:

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

              This  describes  three possible values: `foo', `one', and `two'.
              The first is described as  `bar',  takes  no  argument  and  may
              appear more than once.  The second is described as `number', may
              appear  more  than  once,  and  takes  one  mandatory   argument
              described  as  `first count'; no action is specified, so it will
              not be completed.  The `(two)' at the beginning says that if the
              value  `one'  is  on the line, the value `two' will no longer be
              considered a  possible  completion.   Finally,  the  last  value
              (`two')  is  described as `another number' and takes an optional
              argument described as `second count' for which  the  completions
              (to  appear  after  an  `=') are `1', `2', and `3'.  The _values
              function will complete lists of these values separated  by  com-
              mas.

              Like  _arguments, this function temporarily adds another context
              name component to the arguments element (the fifth) of the  cur-
              rent context while executing the action.  Here this name is just
              the name of the value for which the argument is completed.

              The style verbose is used to decide if the descriptions for  the
              values (but not those for the arguments) should be printed.

              The  associative  array  val_args  is  used to report values and
              their arguments; this works similarly to the  opt_args  associa-
              tive array used by _arguments.  Hence the function calling _val-
              ues should declare the local parameters state, line, context and
              val_args:

                     local context state line
                     typeset -A val_args

              when using an action of the form `->string'.  With this function
              the context parameter will be set to the name of the value whose
              argument is to be completed.

              Note  also  that _values normally adds the character used as the
              separator between values as an auto-removable suffix (similar to
              a  `/'  after a directory).  However, this is not possible for a
              `->string' action as the matches for the argument are  generated
              by  the  calling  function.  To get the usual behaviour, the the
              calling function can add the separator x as a suffix by  passing
              the options `-qS x' either directly or indirectly to compadd.

              The option -C is treated in the same way as it is by _arguments.
              In that case the  parameter  curcontext  should  be  made  local
              instead of context (as described above).

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

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

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

                     local expl
                     _wanted tag expl 'description' \
                         compadd matches...

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

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



COMPLETION DIRECTORIES

       In the source distribution, the files are contained in  various  subdi-
       rectories of the Completion directory.  They may have been installed in
       the same structure, or into one single function directory.  The follow-
       ing  is  a  description  of  the  files found in the original directory
       structure.  If you wish to alter an installed file, you  will  need  to
       copy  it to some directory which appears earlier in your fpath than the
       standard directory where it appears.

       Base   The core functions and special completion widgets  automatically
              bound  to  keys.   You will certainly need most of these, though
              will probably not need to alter them.  Many of these  are  docu-
              mented above.

       Zsh    Functions for completing arguments of shell builtin commands and
              utility functions for this.  Some of  these  are  also  used  by
              functions from the Unix directory.

       Unix   Functions  for  completing  arguments  of  external commands and
              suites of commands.  They may need modifying  for  your  system,
              although in many cases some attempt is made to decide which ver-
              sion of a command is present.  For example, completion  for  the
              mount  command  tries  to determine the system it is running on,
              while completion for many other utilities try to decide  whether
              the  GNU version of the command is in use, and hence whether the
              --help option is supported.

       X, AIX, BSD, ...
              Completion and utility function for commands available  only  on
              some  systems.   These  are not arranged hierarchically, so, for
              example, both the Linux and Debian directories, as well as the X
              directory, may be useful on your system.



zsh 4.3.11                     December 20, 2010                 zshcompsys(1)

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