zshcompsys



ZSHCOMPSYS(1)                                                    ZSHCOMPSYS(1)




NAME

       zshcompsys - zsh completion system


DESCRIPTION

       This  describes  the shell code for the new completion system.  It con-
       sists of various shell functions; those  beginning  ‘comp’  are  to  be
       called directly, while those beginning ‘_’ are called by the completion
       code.  The shell functions of the second set, which  implement  comple-
       tion behaviour and may be bound to keystrokes, are referred to as ‘wid-
       gets’.




INITIALIZATION

       If the system was installed completely, it should be enough to call the
       shell  function  compinit  from  your initialization file; see the next
       section.  However, the function compinstall can be run  by  a  user  to
       configure various aspects of the completion system.

       Usually,  compinstall will insert code into .zshrc, although if that is
       not writable it will save it in another file and tell you  that  file’s
       location.   Note that it is up to you to make sure that the lines added
       to .zshrc are actually run; you may, for example, need to move them  to
       an  earlier place in the file if .zshrc usually returns early.  So long
       as you keep them all together (including the comment lines at the start
       and finish), you can rerun compinstall and it will correctly locate and
       modify these lines.  Note, however, that any code you add to this  sec-
       tion  by  hand  is likely to be lost if you rerun compinstall, although
       lines using the command ‘zstyle’ should be gracefully handled.

       The new code will take effect next time you start  the  shell,  or  run
       .zshrc  by hand; there is also an option to make them take effect imme-
       diately.  However, if compinstall has  removed  definitions,  you  will
       need to restart the shell to see the changes.

       To run compinstall you will need to make sure it is in a directory men-
       tioned in your fpath parameter, which should already be the case if zsh
       was properly configured as long as your startup files do not remove the
       appropriate  directories  from  fpath.   Then  it  must  be  autoloaded
       (‘autoload  -U compinstall’ is recommended).  You can abort the instal-
       lation any time you are being prompted for information, and your .zshrc
       will  not  be altered at all; changes only take place right at the end,
       where you are specifically asked for confirmation.


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

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

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

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

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

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

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

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

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


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

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

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

       The tags are:

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

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

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

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

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

              When one of the key-sequences is typed, the function in the file
              will be invoked to generate the matches.  Note that a  key  will
              not  be  re-bound  if  if  it already was (that is, was bound to
              something other than undefined-key).  The widget created has the
              same  name  as the file and can be bound to any other keys using
              bindkey as usual.

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

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

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

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

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

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

       -array-value-
              The right hand side of an array-assignment (‘foo=(...)’)

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

       -assign-parameter-
              The  name of a parameter in an assignment, i.e. on the left hand
              side of an ‘=-command-
              A word in command position

       -condition-
              A word inside a condition (‘[[...]]’)

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

       -equal-
              A word beginning with an equals sign

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

       -math- Inside mathematical contexts, such as ‘((...))-parameter-
              The name of a parameter expansion (‘$...’)

       -redirect-
              The word after a redirection operator.

       -subscript-
              The contents of a parameter subscript.

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

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

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

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

       For  the  -redirect-  context,  the  extra  information  is in the form
       ‘-redirect-,op,command’, where op is the redirection operator and  com-
       mand is the name of the command on the line.  If there is no command on
       the line yet, the command field will be empty.

       For the -value- context, the form is ‘-value-,name,command’, where name
       is  the  name of the parameter.  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 the following  fields,  separated
       by colons and with a leading colon before the first:

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


       ·      The function, if completion is called from a named widget rather
              than through the normal completion system.   Typically  this  is
              blank,  but  it is set by special widgets such as predict-on and
              the various functions in the Widget directory of  the  distribu-
              tion to the name of that function, often in an abbreviated form.


       ·      The completer currently active, the name of the function without
              the  leading underscore.  A ‘completer’ is in overall control of
              how completion is to be performed; ‘complete’ is  the  simplest,
              but other completers exist to perform related tasks such as cor-
              rection, or to modify the behaviour of a later  completer.   See
              the section ‘Control Functions’ below for more information.


       ·      The command or a special -context-, just at it appears following
              the #compdef tag or the compdef function.  Completion  functions
              for commands that have sub-commands usually modify this field to
              contain the name of the command followed by a minus sign and the
              sub-command.   For  example, the completion function for the cvs
              command sets this field to cvs-add when completing arguments  to
              the add subcommand.


       ·      The  argument; this indicates which command line or option argu-
              ment we are completing.  For command  arguments  this  generally
              takes  the  form  argument-n, where n is the number of the argu-
              ment, and for arguments to options the form option-opt-n where n
              is  the  number of the argument to option opt.  However, this is
              only the case if  the  command  line  is  parsed  with  standard
              UNIX-style options and arguments, so many completions do not set
              this.


       ·      The tag.  Tags are used to discriminate  between  the  types  of
              matches  a completion function can generate in a certain context
              and are described further below.


       As an 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.

       Each  type  of  completion the system can perform in a given context is
       described by a ‘tag’, a short descriptive string such as files  in  the
       example  above.  Any completion function may use any tag name it likes,
       but a list of the more common ones is given below.

       Usually completion will be tried by 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:* completer 
                  if [[ $words[1] = cvs ]]; then
                    reply=(_complete)
                  else
                    reply=(_complete _approximate)
                  fi

       uses the value ‘_complete’ for the completer style  in  most  contexts,
       but  the value ‘_complete _approximate’ when the first word on the com-
       mand line is ‘cvs’.  This is probably more conveniently done by  speci-
       fying  the style for two different contexts.  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 cer-
              tain commands may understand other kinds of function

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

       groups for names of user groups

       history-words
              for words from the history

       hosts  for hostnames

       indexes
              for array indexes

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

       interfaces
              for network interfaces

       keymaps
              for names of zsh keymaps

       keysyms
              for names of X keysyms

       libraries
              for names of system libraries

       limits for system limits

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

       manuals
              for names of manual pages

       mailboxes
              for e-mail folders

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

       messages
              used to look up the format style for messages

       modifiers
              for names of X modifiers

       modules
              for modules (e.g. zsh modules)

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

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

       names  for all kinds of names

       newsgroups
              for USENET groups

       nicknames
              for nicknames of NIS maps

       options
              for command options

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

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

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

       parameters
              for names of parameters

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

       paths  used  to  look  up  the values of the expand, ambiguous and spe-
              cial-dirs styles

       pods   for perl pods (documentation files)

       ports  for communication ports

       prefixes
              for prefixes (like those of a URL)

       printers
              for print queue names

       processes
              for process identifiers

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

       sequences
              for sequences (e.g. mh sequences)

       sessions
              for sessions in the zftp function suite

       signals
              for signal names

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

       styles for styles used by the zstyle builtin command

       suffixes
              for filename extensions

       tags   for tags (e.g. rpm tags)

       targets
              for makefile targets

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

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

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

       users  for usernames

       values for one of a set of values in certain lists

       variant
              used  by _pick_variant to look up the command to run when deter-
              mining what program is installed for a particular command  name.

       visuals
              for X visuals

       warnings
              used to look up the format style for warnings

       widgets
              for zsh widget names

       windows
              for IDs of X windows

       zsh-options
              for shell options


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

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

              zstyle :completion:*:default menu ...

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       command
              In many places, completion functions need to call external  com-
              mands  to  generate  the list of completions.  This style can be
              used to override the command that is called in some such  cases.
              The  elements of the value are joined with spaces to form a com-
              mand line to execute.  The value can also start with  a  hyphen,
              in  which  case the usual command will be added to the end; this
              is most useful for putting ‘builtin’ or ‘command’  in  front  to
              make  sure  the  appropriate version of a command is called, for
              example to avoid calling a shell function with the same name  as
              an external command.

              As an example, the completion function for process IDs uses this
              style with the processes tag to generate the IDs to complete and
              the  list  of  processes  to  display  (if  the verbose style is
              ‘true’).  The list produced by the command should look like  the
              output  of the ps command.  The first line is not displayed, but
              is searched for the string ‘PID’ (or ‘pid’) to find the position
              of the process IDs in the following lines.  If the line does not
              contain ‘PID’, the first numbers in each of the other lines  are
              taken as the process IDs to complete.

              Note  that  the  completion  function  generally has to call the
              specified command for each attempt to  generate  the  completion
              list.   Hence care should be taken to specify only commands that
              take a short time to run, and in particular to  avoid  any  that
              may never terminate.

       command-path
              This  is  a  list  of directories to search for commands to com-
              plete.  The default for this style is the value of  the  special
              parameter path.

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

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

       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’.

       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’.

       disable-stat
              This is used with an empty tag by the _cvs  function  to  decide
              whether  the zsh/stat module should be used to generate names of
              modified files in the appropriate places (this is its only use).
              If the style is set, completion will use the ls command.

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

       expand This  style is used when completing strings consisting of multi-
              ple parts, such as path names.

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

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

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

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

       fake-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.

              This can be useful on systems that support  special  filesystems
              whose  top-level  pathnames  can not be listed or generated with
              glob patterns.  It can also be used for  directories  for  which
              one does not have read permission.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       format If  this is set for the descriptions tag, its value is used as a
              string to  display  above  matches  in  completion  lists.   The
              sequence  ‘%d’  in  this  string  will  be replaced with a short
              description of what these matches are.   This  string  may  also
              contain  the  sequences  to  specify  output attributes, such as
              ‘%B’, ‘%S’ and ‘%{...%}’.

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

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

              Some  completion  functions  display  messages  that may be 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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       list-grouped
              If  this  style  is  ‘true’ (the default), the completion system
              will try to make certain completion  listings  more  compact  by
              grouping  matches.   For example, options for commands that have
              the same description (shown when the verbose  style  is  set  to
              ‘true’)  will appear as a single entry.  However, menu selection
              can be used to cycle through all the matches.

       list-packed
              This is tested for each tag valid in the current context as well
              as  the  default tag.  If it is set to ‘true’, the corresponding
              matches appear in listings as if  the  LIST_PACKED  option  were
              set.  If it is set to ‘false’, they are listed normally.

       list-prompt
              If  this style is set for the default tag, completion lists that
              don’t fit on the screen can be scrolled (see the description  of
              the  zsh/complist  module  in zshmodules(1)).  The value, if not
              the empty string, will be displayed after  every  screenful  and
              the  shell  will  prompt for a key press; if the style is set to
              the empty string, a default prompt will be used.

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

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

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

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

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

              For example:

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

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

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

       match-original
              This is used by the _match completer.  If it  is  set  to  only,
              _match  will  try to generate matches without inserting a ‘*’ at
              the cursor position.  If set to any other  non-empty  value,  it
              will first try to generate matches without inserting the ‘*’ and
              if that yields no matches,  it  will  try  again  with  the  ‘*’
              inserted.   If  it is unset or set to the empty string, matching
              will only be performed with the ‘*’ inserted.

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

       matcher-list
              This style can be set to a list of match specifications that are
              to be applied everywhere. Match specifications are described  in
              the section ‘Matching Control’ in zshcompwid(1).  The completion
              system will try  them  one  after  another  for  each  completer
              selected.   For  example, to try first simple completion and, if
              that generates no matches, case-insensitive completion:

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

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

                     zstyle :completion:* matcher-list  +m{a-Z}={A-Z} +m{A-Z}={a-z}

              It is possible to create match specifications valid for particu-
              lar completers by using the third field  of  the  context.   For
              example,  to  use  the completers _complete and _prefix but only
              allow case-insensitive completion with _complete:

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

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

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

              If  the  style is unset in any context no match specification is
              applied.  Note also that some completers such  as  _correct  and
              _approximate  do not use the match specifications at all, though
              these  completers  will  only  ever  called  once  even  if  the
              matcher-list contains more than one element.

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

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

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

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

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

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

              The default value for this style is ‘2 numeric’.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              old-list
                     This is used by the _oldlist completer.  If it is set  to
                     ‘always’,  then  standard  widgets  which perform listing
                     will retain the current list  of  matches,  however  they
                     were  generated;  this  can be turned off explicitly with
                     the value  ‘never’,  giving  the  behaviour  without  the
                     _oldlist  completer.  If the style is unset, or any other
                     value, then the existing list of completions is displayed
                     if  it is not already; otherwise, the standard completion
                     list is generated;  this  is  the  default  behaviour  of
                     _oldlist.   However,  if  there  is  an old list and this
                     style contains the name of the  completer  function  that
                     generated  the  list, then the old list will be used even
                     if it was generated by a widget which does not  do  list-
                     ing.

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

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

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

                     If this style is set it is generally unwise to  call  the
                     _all_matches completer unconditionally.  One possible use
                     is for either this style or the  completer  style  to  be
                     defined  with  the  -e option to zstyle to make the style
                     conditional.

              old-menu
                     This is used by the _oldlist completer.  It controls  how
                     menu  completion  behaves  when  a completion has already
                     been inserted and the user types  a  standard  completion
                     key  such  as  TAB.  The default behaviour of _oldlist is
                     that menu completion always continues with  the  existing
                     list  of  completions.   If this style is set to ‘false’,
                     however, a new completion is started if the old list  was
                     generated  by a different completion command; this is the
                     behaviour without the _oldlist completer.

                     For example, suppose you type ^Xc to generate a  list  of
                     corrections, and menu completion is started in one of the
                     usual ways.  Usually, or with this style  set  to  false,
                     typing  TAB  at this point would start trying to complete
                     the line as it now appears.  With  _oldlist,  it  instead
                     continues to cycle through the list of corrections.

              original
                     This  is used by the _approximate and _correct completers
                     to decide if the original string should  be  added  as  a
                     possible  completion.   Normally,  this  is  done only if
                     there are at least two possible corrections, but if  this
                     style  is  set  to ‘true’, it is always added.  Note that
                     the style will be examined with the  completer  field  in
                     the  context  name set to correct-num or approximate-num,
                     where num is the number of errors that were accepted.

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

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

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

              path   The  function  that completes color names uses this style
                     with the colors tag.  The value should be the pathname of
                     a  file  containing  color  names in the format of an X11
                     rgb.txt file.  If the style is not set but this  file  is
                     found  in  one  of  various standard locations it will be
                     used as the default.

              pine-directory
                     If set, specifies the directory containing  PINE  mailbox
                     files.  It defaults to ‘~/mail’.

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

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

                     The default value for this style is ‘false’.

              prefix-needed
                     This, too, is used for matches with a common prefix.   If
                     it  is  set to ‘true’ this common prefix must be typed by
                     the user to generate the matches.  In the case of command
                     options,  this  means  that the initial ‘-’, ‘+’, or ‘--’
                     must be typed explicitly before option names will be com-
                     pleted.

                     The default value for this style is ‘true’.

              preserve-prefix
                     This style is used when completing path names.  Its value
                     should be a pattern matching an  initial  prefix  of  the
                     word  to complete that should be left unchanged under all
                     circumstances.  For example, on some  Unices  an  initial
                     ‘//’  (double  slash) has a special meaning; setting this
                     style to the string ‘//’ will preserve  it.   As  another
                     example,  setting  this style to ‘?:/’ under Cygwin would
                     allow completion after ‘a:/...’ and so on.

              range  This is used by the  _history  completer  and  the  _his-
                     tory_complete_word bindable command to decide which words
                     should be completed.

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

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

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

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

              remote-access
                     If set to false, certain commands will be prevented  from
                     making  Internet  connections to retrieve remote informa-
                     tion.  This includes the completion for the CVS  command.

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

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

              select-prompt
                     If this is set for the default tag,  its  value  will  be
                     displayed  during  menu  selection  (see  the  menu style
                     above) when the completion  list  does  not  fit  on  the
                     screen   as  a  whole.   The  same  escapes  as  for  the
                     list-prompt style are understood, except that the numbers
                     refer  to  the  match  or line the mark is on.  A default
                     prompt is used when the value is the empty string.

              select-scroll
                     This style is tested for the default tag  and  determines
                     how a completion list is scrolled during a menu selection
                     (see the menu style above) when the completion list  does
                     not  fit  on  the screen as a whole.  If the value is ‘0’
                     (zero), the list is scrolled by half-screenfuls; if it is
                     a  positive  integer,  the  list is scrolled by the given
                     number of lines; if it is a negative number, the list  is
                     scrolled  by  a screenful minus the absolute value of the
                     given number of lines.  The default is to scroll by  sin-
                     gle lines.

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

              single-ignored
                     This is used by the _ignored completer when there is only
                     one match.  If its value is ‘show’, the single match will
                     be displayed but not inserted.  If the value  is  ‘menu’,
                     then  the  single  match and the original string are both
                     added as matches and menu completion is  started,  making
                     it easy to select either of them.

              sort   Many  completion  widgets call _description at some point
                     which decides whether the matches  are  added  sorted  or
                     unsorted  (often  indirectly  via _wanted or _requested).
                     This style can be set explicitly to one of the usual true
                     or false values as an override.  If it is not set for the
                     context, the standard behaviour of the calling widget  is
                     used.

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

                     If   the  calling  widget  explicitly  requests  unsorted
                     matches, this is usually honoured.  However, the  default
                     (unsorted)  behaviour  of completion for the command his-
                     tory may be overridden by setting the style to true.

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

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

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

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

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

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

              strip-comments
                     If set to ‘true’, this style causes non-essential comment
                     text to be removed from completion matches.  Currently it
                     is  only  used  when completing e-mail addresses where it
                     removes any display name from the addresses, cutting them
                     down to plain user@host form.

              subst-globs-only
                     This  is  used by the _expand completer.  If it is set to
                     ‘true’, the expansion will only be used  if  it  resulted
                     from globbing; hence, if expansions resulted from the use
                     of the substitute style described below, but  these  were
                     not  further  changed by globbing, the expansions will be
                     rejected.

                     The default for this style is ‘false’.

              substitute
                     This boolean style controls whether the _expand completer
                     will  first try to expand all substitutions in the string
                     (such as ‘$(...)’ and ‘${...}’).

                     The default is ‘true’.

              suffix This is used by the _expand completer if the word  starts
                     with a tilde or contains a parameter expansion.  If it is
                     set to ‘true’, the word  will  only  be  expanded  if  it
                     doesn’t  have  a  suffix,  i.e.  if  it is something like
                     ‘~foo’ or  ‘$foo’  rather  than  ‘~foo/’  or  ‘$foo/bar’,
                     unless  that  suffix  itself contains characters eligible
                     for expansion.  The default for this style is ‘true’.

              tag-order
                     This provides a mechanism for sorting how the tags avail-
                     able in a particular context will be used.

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

                     For example:

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

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

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

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

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

                     tag:label ...
                             Here,  tag  is one of the standard tags and label
                             is an arbitrary name.  Matches are  generated  as
                             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,  supply-
                             ing  different  style  settings for each attempt;
                             see below for an example.

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

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

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

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

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

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

                             zstyle :completion:* tag-order \
                                 options:-long:long\ options
                                  options:-short:short\ options
                                  options:-single-letter:single\ letter\ options

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

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

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

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

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

                     It is possible to use the -e option of the zstyle builtin
                     command to specify conditions for the use  of  particular
                     tags.  For example:

                             zstyle -e *:-command-:* tag-order 
                                 if [[ -n $PREFIX$SUFFIX ]]; then
                                   reply=( )
                                 else
                                   reply=( - )
                                 fi

                     Completion  in command position will be attempted only if
                     the string typed so far is not  empty.   This  is  tested
                     using  the PREFIX special parameter; see zshcompwid for a
                     description of parameters which are special  inside  com-
                     pletion  widgets.   Setting  reply to an empty array pro-
                     vides the default behaviour of trying all tags  at  once;
                     setting  it to an array containing only a hyphen disables
                     the use of all tags and hence of all completions.

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

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

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

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

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

                     For example,

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

                     allows  completion  of  all  the  components  of  the URL
                     ftp://ftp.zsh.org/pub/development after suitable commands
                     such as ‘netscape’ or ‘lynx’.  Note, however, that access
                     methods and files are completed  separately,  so  if  the
                     hosts  style is set hosts can be completed without refer-
                     ence to the urls style.

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

              use-cache
                     If this is set, the completion caching layer is activated
                     for any completions which use it (via  the  _store_cache,
                     _retrieve_cache,   and  _cache_invalid  functions).   The
                     directory containing the cache files can be changed  with
                     the cache-path style.

              use-compctl
                     If  this  style is set to a string not equal to false, 0,
                     no, and off, the completion system may use any completion
                     specifications  defined with the compctl builtin command.
                     If the style is unset, this is done only if the  zsh/com-
                     pctl  module  is loaded.  The string may also contain the
                     substring ‘first’ to use completions defined  with  ‘com-
                     pctl  -T’, and the substring ‘default’ to use the comple-
                     tion defined with ‘compctl -D’.

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

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

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

                     Currently this is only used in  completions  for  ‘make’,
                     but  it  may  be extended depending on authorial frustra-
                     tion.

              users  This may be set to a list of usernames to  be  completed.
                     If  it is not set or the string on the line doesn’t match
                     any of the strings in this list, all  usernames  will  be
                     completed.

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

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

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

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

              word   This  is  used by the _list completer, which prevents the
                     insertion  of  completions  until  a  second   completion
                     attempt when the line has not changed.  The normal way of
                     finding out if the line has changed  is  to  compare  its
                     entire contents between the two occasions.  If this style
                     is true, the comparison is instead performed only on  the
                     current  word.   Hence  if  completion  is  performed  on
                     another word with the same contents, completion will  not
                     be delayed.



CONTROL FUNCTIONS

       The initialization script compinit redefines all the widgets which per-
       form completion to call the supplied  widget  function  _main_complete.
       This function acts as a wrapper calling the so-called ‘completer’ func-
       tions that generate matches.  If _main_complete is  called  with  argu-
       ments, these are taken as the names of completer functions to be called
       in the order given.  If no arguments are given, the set of functions to
       try is taken from the completer style.  For example, to use normal com-
       pletion and correction if that doesn’t generate any matches:

              zstyle :completion:* completer _complete _correct

       after calling compinit. The default value for this style is  ‘_complete
       _ignored’,  i.e. normally only ordinary completion is tried, first with
       the effect of the ignored-patterns style  and  then  without  it.   The
       _main_complete  function  uses  the return value of the completer func-
       tions to decide if other completers should be called.   If  the  return
       value  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

       _approximate
              This is similar to the basic _complete completer but allows  the
              completions  to  undergo  corrections.   The  maximum  number of
              errors can  be  specified  by  the  max-errors  style;  see  the
              description of approximate matching in zshexpn(1) for how errors
              are counted.  Normally this completer will only be  tried  after
              the normal _complete completer:

                     zstyle :completion:* completer _complete _approximate

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

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

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

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

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

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

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

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

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

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

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

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

              For example, with:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              For example, consider this global completer style:

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

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

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

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

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

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

       bashcompinit
              This function provides compatibility  with  bash’s  programmable
              completion system.  When run it will define the functions, comp-
              gen and complete which correspond to the bash builtins with  the
              same names.  It will then be possible to use completion specifi-
              cations and functions written for bash.



BINDABLE COMMANDS

       In addition to the context-dependent completions  provided,  which  are
       expected to work in an intuitively obvious way, there are a few widgets
       implementing special behaviour which can be bound separately  to  keys.
       The following is a list of these and their default bindings.

       _bash_completions
              This  function  is  used by two widgets, _bash_complete-word and
              _bash_list-choices.  It exists  to  provide  compatibility  with
              completion  bindings in bash.  The last character of the binding
              determines what is completed: ‘!’, command names; ‘$’,  environ-
              ment  variables;  ‘@’,  host  names;  ‘/’,  file names; ‘~’ user
              names.  In bash, the binding preceded by ‘\e’ gives  completion,
              and  preceded  by ‘^X’ lists options.  As some of these bindings
              clash with standard zsh bindings, only ‘\e~’ and ‘^X~’ are bound
              by  default.   To add the rest, the following should be added to
              .zshrc after compinit has been run:

                     for key in ! $ @ / ~; do
                       bindkey "\e$key" _bash_complete-word
                       bindkey "^X$key" _bash_list-choices
                     done

              This includes the bindings for ‘~’ in  case  they  were  already
              bound  to  something else; the completion code does not override
              user bindings.

       _correct_filename (^XC)
              Correct the filename path at the cursor position.  Allows up  to
              six  errors in the name.  Can also be called with an argument to
              correct a filename path, independently of zle; the correction is
              printed on standard output.

       _correct_word (^Xc)
              Performs correction of the current argument using the usual con-
              textual completions as possible choices. This stores the  string
              ‘correct-word’  in  the  function  field of the context name and
              then calls the _correct completer.

       _expand_alias (^Xa)
              This function can be used as a completer and as a bindable  com-
              mand.   It  expands the word the cursor is on if it is an alias.
              The types of alias expanded can be controlled  with  the  styles
              regular, global and disabled.

              When  used as a bindable command there is one additional feature
              that can be selected by setting the complete  style  to  ‘true’.
              In  this  case,  if  the  word  is  not  the  name  of an alias,
              _expand_alias tries to complete the word to a  full  alias  name
              without  expanding  it.  It leaves the cursor directly after the
              completed word so that invoking  _expand_alias  once  more  will
              expand the now-complete alias name.

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

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

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

       _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
              available.   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_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 zero if they
       generated completions and non-zero if no matching completions could  be
       added.

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

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

              For example:

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

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

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

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

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

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

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

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

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

       _arguments [ -swWACRS ] [ -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.

              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
                             separate 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 a
                     word  matching  the pattern are to be completed 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 zero if it was able to add matches
              and non-zero otherwise. However, if  the  -R  option  is  given,
              _arguments  will instead return a status of 300 to indicate that
              $state is to be handled.

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

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

                     local context state line
                     typeset -A opt_args

              to avoid _arguments from altering the global environment.

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

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

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

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

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

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

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

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

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

       For example:

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

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

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

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

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

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

              foobar -a -- -b

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

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

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

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

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

              local curcontext="$curcontext"

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              Example:

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

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

              The return value 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 value is
              the return value of the command called.

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

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

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

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

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

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

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

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

              The  descr  is taken as a string to display above the matches if
              the format style for the descriptions tag is set.  This is  fol-
              lowed  by one or two names of arrays followed by options to pass
              to compadd.  The first array contains the  possible  completions
              with  their  descriptions  in the form ‘completion:description’.
              If a second array is given, it should have the  same  number  of
              elements  as  the first; in this case the corresponding elements
              are added as possible  completions  instead  of  the  completion
              strings  from  the first array.  The completion list will retain
              the descriptions from the first array.  Finally, a set  of  com-
              pletion options can appear.

              If  the  option  ‘-o’  appears  before  the  first argument, the
              matches added will be treated as names of command options  (N.B.
              not  shell  options),  typically following a ‘-’, ‘--’ or ‘+’ on
              the command line.  In this case _describe uses  the  prefix-hid-
              den, prefix-needed and verbose styles to find out if the strings
              should be added as completions and if the descriptions should be
              shown.   Without the ‘-o’ option, only the verbose style is used
              to decide how descriptions are shown.  If ‘-O’ is  used  instead
              of  ‘-O’,  command  options are completed as above but _describe
              will not handle the prefix-needed style.

              With the -t option a tag can be specified.  The default is ‘val-
              ues’ or, if the -o option is given, ‘options’.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

                     compdef _gnu_generic foo bar

              after the call to compinit.

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

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

              The  pattern may be preceded by any of the options understood by
              compadd that are passed down from _description, namely  -M,  -J,
              -V,  -1,  -2,  -n,  -F  and  -X.   All  of these options will be
              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
              command  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 at the appropriate point.  The pattern  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.

              /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.

       _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 ~/.zsh/cache.  The return
              value 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 ~/.zsh/cache.  The  remaining
              params arguments are the parameters to dump to the file.

              The  return  value 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 value
              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:

                     _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 4.2.1                       August 13, 2004                  ZSHCOMPSYS(1)

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