1ZSHCOMPSYS(1)               General Commands Manual              ZSHCOMPSYS(1)
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NAME

6       zshcompsys - zsh completion system
7

DESCRIPTION

9       This describes the shell code for the `new' completion system, referred
10       to as compsys.  It is written in shell functions based on the  features
11       described in zshcompwid(1).
12
13       The features are contextual, sensitive to the point at which completion
14       is started.  Many completions are already provided.  For this reason, a
15       user  can perform a great many tasks without knowing any details beyond
16       how to initialize the system, which is described below  in  INITIALIZA‐
17       TION.
18
19       The context that decides what completion is to be performed may be
20       •      an  argument  or option position: these describe the position on
21              the command line at which completion is requested.  For  example
22              `first  argument  to rmdir, the word being completed names a di‐
23              rectory';
24
25
26       •      a special context, denoting an element in  the  shell's  syntax.
27              For  example  `a  word  in  command  position' or `an array sub‐
28              script'.
29
30
31       A full context specification contains other elements, as we  shall  de‐
32       scribe.
33
34       Besides  commands  names and contexts, the system employs two more con‐
35       cepts, styles and tags.  These provide ways for the user  to  configure
36       the system's behaviour.
37
38       Tags  play  a dual role.  They serve as a classification system for the
39       matches, typically indicating a class of object that the user may  need
40       to  distinguish.  For example, when completing arguments of the ls com‐
41       mand the user may prefer to try files before directories,  so  both  of
42       these are tags.  They also appear as the rightmost element in a context
43       specification.
44
45       Styles modify various operations of the completion system, such as out‐
46       put formatting, but also what kinds of completers are used (and in what
47       order), or which tags are examined.  Styles may  accept  arguments  and
48       are manipulated using the zstyle command described in zshmodules(1).
49
50       In  summary,  tags  describe what the completion objects are, and style
51       how they are to be completed.  At various points of execution, the com‐
52       pletion  system checks what styles and/or tags are defined for the cur‐
53       rent context, and uses that to modify its behavior.  The full  descrip‐
54       tion  of context handling, which determines how tags and other elements
55       of the context influence the behaviour of styles, is described below in
56       COMPLETION SYSTEM CONFIGURATION.
57
58       When  a  completion  is requested, a dispatcher function is called; see
59       the description of _main_complete in the list of control functions  be‐
60       low. This dispatcher decides which function should be called to produce
61       the completions, and calls it. The result is passed to one or more com‐
62       pleters,  functions  that  implement  individual completion strategies:
63       simple completion, error correction, completion with error  correction,
64       menu selection, etc.
65
66       More  generally, the shell functions contained in the completion system
67       are of two types:
68       •      those beginning `comp' are to be called directly; there are only
69              a few of these;
70
71
72       •      those  beginning  `_'  are  called  by the completion code.  The
73              shell functions of this set, which implement  completion  behav‐
74              iour  and  may  be bound to keystrokes, are referred to as `wid‐
75              gets'.  These proliferate as new completions are required.
76
77

INITIALIZATION

79       If the system was installed completely, it should be enough to call the
80       shell  function  compinit  from  your initialization file; see the next
81       section.  However, the function compinstall can be run  by  a  user  to
82       configure various aspects of the completion system.
83
84       Usually,  compinstall will insert code into .zshrc, although if that is
85       not writable it will save it in another file and tell you  that  file's
86       location.   Note that it is up to you to make sure that the lines added
87       to .zshrc are actually run; you may, for example, need to move them  to
88       an  earlier place in the file if .zshrc usually returns early.  So long
89       as you keep them all together (including the comment lines at the start
90       and finish), you can rerun compinstall and it will correctly locate and
91       modify these lines.  Note, however, that any code you add to this  sec‐
92       tion  by  hand  is likely to be lost if you rerun compinstall, although
93       lines using the command `zstyle' should be gracefully handled.
94
95       The new code will take effect next time you start  the  shell,  or  run
96       .zshrc  by hand; there is also an option to make them take effect imme‐
97       diately.  However, if compinstall has  removed  definitions,  you  will
98       need to restart the shell to see the changes.
99
100       To run compinstall you will need to make sure it is in a directory men‐
101       tioned in your fpath parameter, which should already be the case if zsh
102       was properly configured as long as your startup files do not remove the
103       appropriate directories from fpath.  Then it must be  autoloaded  (`au‐
104       toload -U compinstall' is recommended).  You can abort the installation
105       any time you are being prompted for information, and your  .zshrc  will
106       not  be altered at all; changes only take place right at the end, where
107       you are specifically asked for confirmation.
108
109   Use of compinit
110       This section describes the use of compinit to initialize completion for
111       the  current  session when called directly; if you have run compinstall
112       it will be called automatically from your .zshrc.
113
114       To initialize the system, the function compinit should be in  a  direc‐
115       tory  mentioned  in the fpath parameter, and should be autoloaded (`au‐
116       toload -U compinit' is recommended), and then run simply as `compinit'.
117       This will define a few utility functions, arrange for all the necessary
118       shell functions to be autoloaded, and will then re-define  all  widgets
119       that  do  completion to use the new system.  If you use the menu-select
120       widget, which is part of the zsh/complist module, you should make  sure
121       that  that  module  is  loaded before the call to compinit so that that
122       widget is also re-defined.  If completion styles (see below) are set up
123       to  perform expansion as well as completion by default, and the TAB key
124       is bound  to  expand-or-complete,  compinit  will  rebind  it  to  com‐
125       plete-word; this is necessary to use the correct form of expansion.
126
127       Should  you need to use the original completion commands, you can still
128       bind keys to the old widgets by putting a `.' in front  of  the  widget
129       name, e.g. `.expand-or-complete'.
130
131       To speed up the running of compinit, it can be made to produce a dumped
132       configuration that will be read in on future invocations; this  is  the
133       default,  but can be turned off by calling compinit with the option -D.
134       The dumped file is .zcompdump in the  same  directory  as  the  startup
135       files  (i.e.  $ZDOTDIR  or $HOME); alternatively, an explicit file name
136       can be given  by  `compinit  -d  dumpfile'.   The  next  invocation  of
137       compinit  will  read  the dumped file instead of performing a full ini‐
138       tialization.
139
140       If the number of completion files changes, compinit will recognise this
141       and produce a new dump file.  However, if the name of a function or the
142       arguments in the first line of a #compdef function (as described below)
143       change,  it is easiest to delete the dump file by hand so that compinit
144       will re-create it the next time it is run.  The check performed to  see
145       if  there are new functions can be omitted by giving the option -C.  In
146       this case the dump file will only be created if  there  isn't  one  al‐
147       ready.
148
149       The  dumping  is  actually  done by another function, compdump, but you
150       will only need to run this yourself if  you  change  the  configuration
151       (e.g.  using  compdef)  and then want to dump the new one.  The name of
152       the old dumped file will be remembered for this purpose.
153
154       If the parameter _compdir is set, compinit uses it as a directory where
155       completion  functions  can be found; this is only necessary if they are
156       not already in the function search path.
157
158       For security reasons compinit also  checks  if  the  completion  system
159       would  use  files not owned by root or by the current user, or files in
160       directories that are world- or group-writable or that are not owned  by
161       root  or  by the current user.  If such files or directories are found,
162       compinit will ask if the completion system should really be  used.   To
163       avoid  these tests and make all files found be used without asking, use
164       the option -u, and to make compinit silently ignore all insecure  files
165       and  directories use the option -i.  This security check is skipped en‐
166       tirely when the -C option is given, provided the dumpfile exists.
167
168       The security check can be retried at any time by running  the  function
169       compaudit.  This is the same check used by compinit, but when it is ex‐
170       ecuted directly any changes to fpath are made local to the function  so
171       they  do  not  persist.  The directories to be checked may be passed as
172       arguments; if none are given, compaudit uses fpath and _compdir to find
173       completion  system  directories, adding missing ones to fpath as neces‐
174       sary.  To force a check of exactly the directories currently  named  in
175       fpath,  set  _compdir  to  an  empty string before calling compaudit or
176       compinit.
177
178       The function bashcompinit provides compatibility with  bash's  program‐
179       mable  completion system.  When run it will define the functions, comp‐
180       gen and complete which correspond to the bash builtins  with  the  same
181       names.   It  will then be possible to use completion specifications and
182       functions written for bash.
183
184   Autoloaded files
185       The convention for autoloaded functions used in completion is that they
186       start with an underscore; as already mentioned, the fpath/FPATH parame‐
187       ter must contain the directory in which they are stored.   If  zsh  was
188       properly  installed on your system, then fpath/FPATH automatically con‐
189       tains the required directories for the standard functions.
190
191       For incomplete installations, if compinit does not  find  enough  files
192       beginning with an underscore (fewer than twenty) in the search path, it
193       will try to find more by adding the directory _compdir  to  the  search
194       path.  If that directory has a subdirectory named Base, all subdirecto‐
195       ries will be added to the path.  Furthermore, if the subdirectory  Base
196       has  a subdirectory named Core, compinit will add all subdirectories of
197       the subdirectories to the path: this allows the functions to be in  the
198       same format as in the zsh source distribution.
199
200       When  compinit  is  run,  it  searches  all  such  files accessible via
201       fpath/FPATH and reads the first line of each of them.  This line should
202       contain  one  of the tags described below.  Files whose first line does
203       not start with one of these tags are not considered to be part  of  the
204       completion system and will not be treated specially.
205
206       The tags are:
207
208       #compdef name ... [ -{p|P} pattern ... [ -N name ... ] ]
209              The  file  will be made autoloadable and the function defined in
210              it will be called when completing names, each of which is either
211              the name of a command whose arguments are to be completed or one
212              of a number of special contexts in the form -context-  described
213              below.
214
215              Each  name may also be of the form `cmd=service'.  When complet‐
216              ing the command cmd, the function typically behaves  as  if  the
217              command  (or  special  context)  service was being completed in‐
218              stead.  This provides a way of altering the behaviour  of  func‐
219              tions that can perform many different completions.  It is imple‐
220              mented by setting the parameter $service when calling the  func‐
221              tion;  the  function may choose to interpret this how it wishes,
222              and simpler functions will probably ignore it.
223
224              If the #compdef line contains one of the options -p or  -P,  the
225              words  following are taken to be patterns.  The function will be
226              called when completion is attempted for  a  command  or  context
227              that  matches  one  of  the patterns.  The options -p and -P are
228              used to specify patterns to be tried before or after other  com‐
229              pletions  respectively.  Hence -P may be used to specify default
230              actions.
231
232              The option -N is used after a list following -p or -P; it speci‐
233              fies that remaining words no longer define patterns.  It is pos‐
234              sible to toggle between the three options as many times as  nec‐
235              essary.
236
237       #compdef -k style key-sequence ...
238              This  option  creates  a widget behaving like the builtin widget
239              style and binds it to the  given  key-sequences,  if  any.   The
240              style  must  be  one of the builtin widgets that perform comple‐
241              tion, namely complete-word, delete-char-or-list,  expand-or-com‐
242              plete,  expand-or-complete-prefix,  list-choices, menu-complete,
243              menu-expand-or-complete,  or  reverse-menu-complete.    If   the
244              zsh/complist  module  is  loaded  (see zshmodules(1)) the widget
245              menu-select is also available.
246
247              When one of the key-sequences is typed, the function in the file
248              will  be  invoked to generate the matches.  Note that a key will
249              not be re-bound if it already was (that is, was bound  to  some‐
250              thing  other  than  undefined-key).   The widget created has the
251              same name as the file and can be bound to any other  keys  using
252              bindkey as usual.
253
254       #compdef -K widget-name style key-sequence [ name style seq ... ]
255              This is similar to -k except that only one key-sequence argument
256              may be given for each widget-name style pair.  However, the  en‐
257              tire set of three arguments may be repeated with a different set
258              of arguments.  Note in particular that the widget-name  must  be
259              distinct  in  each set.  If it does not begin with `_' this will
260              be added.  The widget-name should not clash with the name of any
261              existing  widget:  names  based  on the name of the function are
262              most useful.  For example,
263
264                     #compdef -K _foo_complete complete-word "^X^C" \
265                       _foo_list list-choices "^X^D"
266
267              (all on one line) defines a widget _foo_complete for completion,
268              bound  to  `^X^C',  and a widget _foo_list for listing, bound to
269              `^X^D'.
270
271       #autoload [ options ]
272              Functions with the #autoload tag are marked for autoloading  but
273              are  not  otherwise treated specially.  Typically they are to be
274              called from within one of the completion functions.  Any options
275              supplied  will  be passed to the autoload builtin; a typical use
276              is +X to force the function to be loaded immediately.  Note that
277              the -U and -z flags are always added implicitly.
278
279       The  #  is part of the tag name and no white space is allowed after it.
280       The #compdef tags use the compdef function described  below;  the  main
281       difference is that the name of the function is supplied implicitly.
282
283       The special contexts for which completion functions can be defined are:
284
285       -array-value-
286              The right hand side of an array-assignment (`name=(...)')
287
288       -assign-parameter-
289              The  name of a parameter in an assignment, i.e. on the left hand
290              side of an `='
291
292       -brace-parameter-
293              The name of a parameter expansion within braces (`${...}')
294
295       -command-
296              A word in command position
297
298       -condition-
299              A word inside a condition (`[[...]]')
300
301       -default-
302              Any word for which no other completion is defined
303
304       -equal-
305              A word beginning with an equals sign
306
307       -first-
308              This is tried before any other completion function.   The  func‐
309              tion  called  may  set the _compskip parameter to one of various
310              values: all: no further completion is attempted; a  string  con‐
311              taining  the substring patterns: no pattern completion functions
312              will be called; a string containing default:  the  function  for
313              the  `-default-'  context  will not be called, but functions de‐
314              fined for commands will be.
315
316       -math- Inside mathematical contexts, such as `((...))'
317
318       -parameter-
319              The name of a parameter expansion (`$...')
320
321       -redirect-
322              The word after a redirection operator.
323
324       -subscript-
325              The contents of a parameter subscript.
326
327       -tilde-
328              After an initial tilde (`~'), but before the first slash in  the
329              word.
330
331       -value-
332              On the right hand side of an assignment.
333
334       Default  implementations  are  supplied for each of these contexts.  In
335       most cases the context -context-  is  implemented  by  a  corresponding
336       function  _context,  for example the context `-tilde-' and the function
337       `_tilde').
338
339       The contexts -redirect- and -value- allow extra context-specific infor‐
340       mation.  (Internally, this is handled by the functions for each context
341       calling the function _dispatch.)  The extra information is added  sepa‐
342       rated by commas.
343
344       For  the -redirect- context, the extra information is in the form `-re‐
345       direct-,op,command', where op is the redirection operator  and  command
346       is  the name of the command on the line.  If there is no command on the
347       line yet, the command field will be empty.
348
349       For the -value- context, the form is `-value-,name,command', where name
350       is  the  name of the parameter on the left hand side of the assignment.
351       In the case of elements of  an  associative  array,  for  example  `as‐
352       soc=(key  <TAB>',  name  is expanded to `name-key'.  In certain special
353       contexts, such as completing after `make  CFLAGS=',  the  command  part
354       gives the name of the command, here make; otherwise it is empty.
355
356       It  is  not necessary to define fully specific completions as the func‐
357       tions provided will try to generate completions  by  progressively  re‐
358       placing  the  elements  with `-default-'.  For example, when completing
359       after `foo=<TAB>', _value will try the names `-value-,foo,'  (note  the
360       empty command part), `-value-,foo,-default-' and`-value-,-default-,-de‐
361       fault-', in that order, until it finds a function to  handle  the  con‐
362       text.
363
364       As an example:
365
366              compdef '_files -g "*.log"' '-redirect-,2>,-default-'
367
368       completes  files matching `*.log' after `2> <TAB>' for any command with
369       no more specific handler defined.
370
371       Also:
372
373              compdef _foo -value-,-default-,-default-
374
375       specifies that _foo provides completions for the values  of  parameters
376       for  which  no special function has been defined.  This is usually han‐
377       dled by the function _value itself.
378
379       The same lookup rules are used when looking up styles (as described be‐
380       low); for example
381
382              zstyle ':completion:*:*:-redirect-,2>,*:*' file-patterns '*.log'
383
384       is  another  way  to  make  completion  after `2> <TAB>' complete files
385       matching `*.log'.
386
387   Functions
388       The following function is defined by compinit and  may  be  called  di‐
389       rectly.
390
391       compdef [ -ane ] function name ... [ -{p|P} pattern ... [ -N name ...]]
392       compdef -d name ...
393       compdef -k [ -an ] function style key-sequence [ key-sequence ... ]
394       compdef -K [ -an ] function name style key-seq [ name style seq ... ]
395              The  first  form  defines the function to call for completion in
396              the given contexts as described for the #compdef tag above.
397
398              Alternatively, all the arguments may  have  the  form  `cmd=ser‐
399              vice'.   Here  service  should  already  have  been  defined  by
400              `cmd1=service' lines in #compdef files, as described above.  The
401              argument for cmd will be completed in the same way as service.
402
403              The  function  argument may alternatively be a string containing
404              almost any shell code.  If the string contains  an  equal  sign,
405              the  above  will  take precedence.  The option -e may be used to
406              specify the first argument is to be evaluated as shell code even
407              if it contains an equal sign.  The string will be executed using
408              the eval builtin command to generate completions.  This provides
409              a  way  of  avoiding having to define a new completion function.
410              For example, to complete files ending in `.h'  as  arguments  to
411              the command foo:
412
413                     compdef '_files -g "*.h"' foo
414
415              The  option  -n prevents any completions already defined for the
416              command or context from being overwritten.
417
418              The option -d deletes any completion defined for the command  or
419              contexts listed.
420
421              The  names  may  also contain -p, -P and -N options as described
422              for the #compdef tag.  The effect on the argument list is  iden‐
423              tical,  switching  between  definitions  of  patterns tried ini‐
424              tially, patterns tried finally, and  normal  commands  and  con‐
425              texts.
426
427              The  parameter $_compskip may be set by any function defined for
428              a pattern context.  If it is set to a value containing the  sub‐
429              string  `patterns' none of the pattern-functions will be called;
430              if it is set to a value containing the substring `all', no other
431              function  will  be called.  Setting $_compskip in this manner is
432              of particular utility when using the -p option, as otherwise the
433              dispatcher  will move on to additional functions (likely the de‐
434              fault one) after calling the pattern-context one, which can man‐
435              gle the display of completion possibilities if not handled prop‐
436              erly.
437
438              The form with -k defines a widget with  the  same  name  as  the
439              function that will be called for each of the key-sequences; this
440              is like the #compdef -k tag.  The function should  generate  the
441              completions  needed  and  will otherwise behave like the builtin
442              widget whose name is given as the style argument.   The  widgets
443              usable  for  this  are:  complete-word, delete-char-or-list, ex‐
444              pand-or-complete,    expand-or-complete-prefix,    list-choices,
445              menu-complete,  menu-expand-or-complete,  and  reverse-menu-com‐
446              plete, as well as menu-select  if  the  zsh/complist  module  is
447              loaded.  The option -n prevents the key being bound if it is al‐
448              ready to bound to something other than undefined-key.
449
450              The form with -K is similar and defines multiple  widgets  based
451              on  the  same  function, each of which requires the set of three
452              arguments name, style and key-sequence, where the latter two are
453              as  for  -k and the first must be a unique widget name beginning
454              with an underscore.
455
456              Wherever applicable, the -a option makes the function  autoload‐
457              able, equivalent to autoload -U function.
458
459       The function compdef can be used to associate existing completion func‐
460       tions with new commands.  For example,
461
462              compdef _pids foo
463
464       uses the function _pids to complete process IDs for the command foo.
465
466       Note also the _gnu_generic function described below, which can be  used
467       to complete options for commands that understand the `--help' option.
468

COMPLETION SYSTEM CONFIGURATION

470       This section gives a short overview of how the completion system works,
471       and then more detail on how users can configure how  and  when  matches
472       are generated.
473
474   Overview
475       When  completion is attempted somewhere on the command line the comple‐
476       tion system begins building the context.  The context represents every‐
477       thing  that  the  shell knows about the meaning of the command line and
478       the significance of the cursor position.  This takes account of a  num‐
479       ber  of things including the command word (such as `grep' or `zsh') and
480       options to which the current word may be an argument (such as the  `-o'
481       option to zsh which takes a shell option as an argument).
482
483       The  context  starts out very generic ("we are beginning a completion")
484       and becomes more specific as more is learned ("the current word is in a
485       position  that is usually a command name" or "the current word might be
486       a variable name" and so on).  Therefore the context  will  vary  during
487       the same call to the completion system.
488
489       This  context information is condensed into a string consisting of mul‐
490       tiple fields separated by colons, referred to simply as  `the  context'
491       in the remainder of the documentation.  Note that a user of the comple‐
492       tion system rarely needs to compose a context string, unless for  exam‐
493       ple  a  new  function  is being written to perform completion for a new
494       command.  What a user may need to do is compose a style pattern,  which
495       is  matched  against a context when needed to look up context-sensitive
496       options that configure the completion system.
497
498       The next few paragraphs explain how a context is  composed  within  the
499       completion  function suite.  Following that is discussion of how styles
500       are defined.  Styles determine such things as how the matches are  gen‐
501       erated,  similarly  to  shell options but with much more control.  They
502       are defined with the zstyle builtin command (see zshmodules(1)).
503
504       The context string always consists of a fixed set of fields,  separated
505       by  colons and with a leading colon before the first.  Fields which are
506       not yet known are left empty, but the surrounding colons appear anyway.
507       The  fields are always in the order :completion:function:completer:com‐
508       mand:argument:tag.  These have the following meaning:
509
510       •      The literal string completion, saying that this style is used by
511              the  completion  system.   This  distinguishes  the context from
512              those used by, for example, zle widgets and ZFTP functions.
513
514
515       •      The function, if completion is called from a named widget rather
516              than  through  the  normal completion system.  Typically this is
517              blank, but it is set by special widgets such as  predict-on  and
518              the  various  functions in the Widget directory of the distribu‐
519              tion to the name of that function, often in an abbreviated form.
520
521
522       •      The completer currently active, the name of the function without
523              the  leading  underscore and with other underscores converted to
524              hyphens.  A `completer' is in overall control of how  completion
525              is  to  be performed; `complete' is the simplest, but other com‐
526              pleters exist to perform related tasks such as correction, or to
527              modify  the  behaviour  of  a  later completer.  See the section
528              `Control Functions' below for more information.
529
530
531       •      The command or a special -context-, just at it appears following
532              the  #compdef tag or the compdef function.  Completion functions
533              for commands that have sub-commands usually modify this field to
534              contain the name of the command followed by a minus sign and the
535              sub-command.  For example, the completion function for  the  cvs
536              command  sets this field to cvs-add when completing arguments to
537              the add subcommand.
538
539
540       •      The argument; this indicates which command line or option  argu‐
541              ment  we  are  completing.  For command arguments this generally
542              takes the form argument-n, where n is the number  of  the  argu‐
543              ment, and for arguments to options the form option-opt-n where n
544              is the number of the argument to option opt.  However,  this  is
545              only  the  case  if  the  command  line  is parsed with standard
546              UNIX-style options and arguments, so many completions do not set
547              this.
548
549
550       •      The tag.  As described previously, tags are used to discriminate
551              between the types of matches a completion function can  generate
552              in  a  certain context.  Any completion function may use any tag
553              name it likes, but a list of the more common ones is  given  be‐
554              low.
555
556
557       The  context  is  gradually put together as the functions are executed,
558       starting with the main entry point, which  adds  :completion:  and  the
559       function  element  if necessary.  The completer then adds the completer
560       element.  The contextual completion adds the command and  argument  op‐
561       tions.   Finally,  the  tag  is  added when the types of completion are
562       known.  For example, the context name
563
564              :completion::complete:dvips:option-o-1:files
565
566       says that normal completion was attempted as the first argument to  the
567       option -o of the command dvips:
568
569              dvips -o ...
570
571       and the completion function will generate filenames.
572
573       Usually  completion  will  be  tried  for all possible tags in an order
574       given by the completion function.  However, this can be altered by  us‐
575       ing  the tag-order style.  Completion is then restricted to the list of
576       given tags in the given order.
577
578       The _complete_help bindable command shows all  the  contexts  and  tags
579       available  for completion at a particular point.  This provides an easy
580       way of finding information for tag-order and other styles.  It  is  de‐
581       scribed in the section `Bindable Commands' below.
582
583       When  looking  up styles the completion system uses full context names,
584       including the tag.  Looking up the value of a style therefore  consists
585       of two things: the context, which is matched to the most specific (best
586       fitting) pattern, and the name of  the  style  itself,  which  must  be
587       matched  exactly.  The following examples demonstrate that patterns may
588       be loosely defined for styles that apply broadly, or as tightly defined
589       as desired for styles that apply in narrower circumstances.
590
591       For example, many completion functions can generate matches in a simple
592       and a verbose form and use the  verbose  style  to  decide  which  form
593       should be used.  To make all such functions use the verbose form, put
594
595              zstyle ':completion:*' verbose yes
596
597       in  a startup file (probably .zshrc).  This gives the verbose style the
598       value yes in every context inside the completion  system,  unless  that
599       context has a more specific definition.  It is best to avoid giving the
600       pattern as `*' in case the style has some meaning outside  the  comple‐
601       tion system.
602
603       Many  such general purpose styles can be configured simply by using the
604       compinstall function.
605
606       A more specific example of the use of the verbose style is by the  com‐
607       pletion  for  the kill builtin.  If the style is set, the builtin lists
608       full job texts and process command lines; otherwise it shows  the  bare
609       job numbers and PIDs.  To turn the style off for this use only:
610
611              zstyle ':completion:*:*:kill:*:*' verbose no
612
613       For  even  more  control,  the  style can use one of the tags `jobs' or
614       `processes'.  To turn off verbose display only for jobs:
615
616              zstyle ':completion:*:*:kill:*:jobs' verbose no
617
618       The -e option to zstyle even allows completion function code to  appear
619       as the argument to a style; this requires some understanding of the in‐
620       ternals of completion functions (see see zshcompwid(1))).  For example,
621
622              zstyle -e ':completion:*' hosts 'reply=($myhosts)'
623
624       This forces the value of the hosts style to be read from  the  variable
625       myhosts each time a host name is needed; this is useful if the value of
626       myhosts can change dynamically.  For another useful  example,  see  the
627       example in the description of the file-list style below.  This form can
628       be slow and should be avoided for commonly examined styles such as menu
629       and list-rows-first.
630
631       Note  that  the  order in which styles are defined does not matter; the
632       style mechanism uses the most specific possible match for a  particular
633       style  to determine the set of values.  Strings are preferred over pat‐
634       terns (for example, `:completion::complete:::foo' is more specific than
635       `:completion::complete:::*'),  and  longer  patterns are preferred over
636       the pattern `*'. See zmodules(1) for details.
637
638       Context patterns that use something other than a wildcard (*) to  match
639       the middle parts of the context -- the completer, command, and argument
640       in :completion:function:completer:command:argument:tag  --  should  in‐
641       clude  all  six  colons (:) explicitly. Without this, a pattern such as
642       :completion:*:foo:* could match foo against a component other than  the
643       intended  one (for example, against completer when a match against com‐
644       mand was intended).
645
646       Style names like those of tags are arbitrary and depend on the  comple‐
647       tion  function.   However,  the following two sections list some of the
648       most common tags and styles.
649
650   Standard Tags
651       Some of the following are only used when looking up  particular  styles
652       and do not refer to a type of match.
653
654       accounts
655              used to look up the users-hosts style
656
657       all-expansions
658              used by the _expand completer when adding the single string con‐
659              taining all possible expansions
660
661       all-files
662              for the names of all files (as distinct from a  particular  sub‐
663              set, see the globbed-files tag).
664
665       arguments
666              for arguments to a command
667
668       arrays for names of array parameters
669
670       association-keys
671              for  keys  of  associative arrays; used when completing inside a
672              subscript to a parameter of this type
673
674       bookmarks
675              when completing bookmarks (e.g. for URLs and the  zftp  function
676              suite)
677
678       builtins
679              for names of builtin commands
680
681       characters
682              for  single  characters  in  arguments of commands such as stty.
683              Also used when completing character  classes  after  an  opening
684              bracket
685
686       colormapids
687              for X colormap ids
688
689       colors for color names
690
691       commands
692              for  names  of external commands.  Also used by complex commands
693              such as cvs when completing names subcommands.
694
695       contexts
696              for contexts in arguments to the zstyle builtin command
697
698       corrections
699              used by the _approximate and _correct  completers  for  possible
700              corrections
701
702       cursors
703              for cursor names used by X programs
704
705       default
706              used  in  some  contexts to provide a way of supplying a default
707              when more specific tags are also valid.  Note that this  tag  is
708              used when only the function field of the context name is set
709
710       descriptions
711              used  when  looking up the value of the format style to generate
712              descriptions for types of matches
713
714       devices
715              for names of device special files
716
717       directories
718              for names of directories -- local-directories  is  used  instead
719              when  completing  arguments  of  cd and related builtin commands
720              when the cdpath array is set
721
722       directory-stack
723              for entries in the directory stack
724
725       displays
726              for X display names
727
728       domains
729              for network domains
730
731       email-plugin
732              for  email  addresses  from  the  `_email-plugin'   backend   of
733              _email_addresses
734
735       expansions
736              used  by  the _expand completer for individual words (as opposed
737              to the complete set of expansions) resulting from the  expansion
738              of a word on the command line
739
740       extensions
741              for X server extensions
742
743       file-descriptors
744              for numbers of open file descriptors
745
746       files  the generic file-matching tag used by functions completing file‐
747              names
748
749       fonts  for X font names
750
751       fstypes
752              for file system types (e.g. for the mount command)
753
754       functions
755              names of functions -- normally shell functions, although certain
756              commands may understand other kinds of function
757
758       globbed-files
759              for filenames when the name has been generated by pattern match‐
760              ing
761
762       groups for names of user groups
763
764       history-words
765              for words from the history
766
767       hosts  for hostnames
768
769       indexes
770              for array indexes
771
772       interfaces
773              for network interfaces
774
775       jobs   for jobs (as listed by the `jobs' builtin)
776
777       keymaps
778              for names of zsh keymaps
779
780       keysyms
781              for names of X keysyms
782
783       libraries
784              for names of system libraries
785
786       limits for system limits
787
788       local-directories
789              for names of directories that are subdirectories of the  current
790              working  directory  when  completing arguments of cd and related
791              builtin commands (compare path-directories) -- when  the  cdpath
792              array is unset, directories is used instead
793
794       mailboxes
795              for e-mail folders
796
797       manuals
798              for names of manual pages
799
800       maps   for map names (e.g. NIS maps)
801
802       messages
803              used to look up the format style for messages
804
805       modifiers
806              for names of X modifiers
807
808       modules
809              for modules (e.g. zsh modules)
810
811       my-accounts
812              used to look up the users-hosts style
813
814       named-directories
815              for  named  directories  (you  wouldn't have guessed that, would
816              you?)
817
818       names  for all kinds of names
819
820       newsgroups
821              for USENET groups
822
823       nicknames
824              for nicknames of NIS maps
825
826       options
827              for command options
828
829       original
830              used by the _approximate, _correct and _expand  completers  when
831              offering the original string as a match
832
833       other-accounts
834              used to look up the users-hosts style
835
836       packages
837              for packages (e.g. rpm or installed Debian packages)
838
839       parameters
840              for names of parameters
841
842       path-directories
843              for  names  of  directories  found by searching the cdpath array
844              when completing arguments of cd  and  related  builtin  commands
845              (compare local-directories)
846
847       paths  used  to  look  up  the values of the expand, ambiguous and spe‐
848              cial-dirs styles
849
850       pods   for perl pods (documentation files)
851
852       ports  for communication ports
853
854       prefixes
855              for prefixes (like those of a URL)
856
857       printers
858              for print queue names
859
860       processes
861              for process identifiers
862
863       processes-names
864              used to look up the command style when generating the  names  of
865              processes for killall
866
867       sequences
868              for sequences (e.g. mh sequences)
869
870       sessions
871              for sessions in the zftp function suite
872
873       signals
874              for signal names
875
876       strings
877              for  strings  (e.g.  the  replacement strings for the cd builtin
878              command)
879
880       styles for styles used by the zstyle builtin command
881
882       suffixes
883              for filename extensions
884
885       tags   for tags (e.g. rpm tags)
886
887       targets
888              for makefile targets
889
890       time-zones
891              for time zones (e.g. when setting the TZ parameter)
892
893       types  for types of whatever (e.g. address types for the xhost command)
894
895       urls   used to look up the urls and local styles when completing URLs
896
897       users  for usernames
898
899       values for one of a set of values in certain lists
900
901       variant
902              used by _pick_variant to look up the command to run when  deter‐
903              mining what program is installed for a particular command name.
904
905       visuals
906              for X visuals
907
908       warnings
909              used to look up the format style for warnings
910
911       widgets
912              for zsh widget names
913
914       windows
915              for IDs of X windows
916
917       zsh-options
918              for shell options
919
920   Standard Styles
921       Note  that the values of several of these styles represent boolean val‐
922       ues.  Any of the strings `true', `on', `yes', and `1' can be  used  for
923       the  value  `true' and any of the strings `false', `off', `no', and `0'
924       for the value `false'.  The behavior for any other value  is  undefined
925       except  where  explicitly  mentioned.   The default value may be either
926       `true' or `false' if the style is not set.
927
928       Some of these styles are tested first for  every  possible  tag  corre‐
929       sponding to a type of match, and if no style was found, for the default
930       tag.  The most notable styles of this type are  menu,  list-colors  and
931       styles   controlling   completion   listing  such  as  list-packed  and
932       last-prompt.  When tested for the default tag, only the function  field
933       of  the  context will be set so that a style using the default tag will
934       normally be defined along the lines of:
935
936              zstyle ':completion:*:default' menu ...
937
938       accept-exact
939              This is tested for the default tag in addition to the tags valid
940              for  the current context.  If it is set to `true' and any of the
941              trial matches is the same as the string  on  the  command  line,
942              this match will immediately be accepted (even if it would other‐
943              wise be considered ambiguous).
944
945              When completing pathnames (where the tag used is  `paths')  this
946              style accepts any number of patterns as the value in addition to
947              the boolean values.  Pathnames matching one  of  these  patterns
948              will  be  accepted immediately even if the command line contains
949              some more partially typed pathname components and these match no
950              file under the directory accepted.
951
952              This  style  is  also used by the _expand completer to decide if
953              words beginning with a tilde or parameter  expansion  should  be
954              expanded.   For example, if there are parameters foo and foobar,
955              the string `$foo' will only be expanded if accept-exact  is  set
956              to  `true';  otherwise  the completion system will be allowed to
957              complete $foo to $foobar. If the style  is  set  to  `continue',
958              _expand  will  add  the  expansion as a match and the completion
959              system will also be allowed to continue.
960
961       accept-exact-dirs
962              This is used by filename completion.  Unlike accept-exact it  is
963              a  boolean.  By default, filename completion examines all compo‐
964              nents of a path to see if there are completions of  that  compo‐
965              nent,  even if the component matches an existing directory.  For
966              example, when completion after /usr/bin/, the function  examines
967              possible completions to /usr.
968
969              When  this style is `true', any prefix of a path that matches an
970              existing directory is accepted without any attempt  to  complete
971              it  further.  Hence, in the given example, the path /usr/bin/ is
972              accepted immediately and completion tried in that directory.
973
974              This style is also useful when completing after directories that
975              magically  appear  when referenced, such as ZFS .zfs directories
976              or NetApp .snapshot directories.  When  the  style  is  set  the
977              shell  does  not check for the existence of the directory within
978              the parent directory.
979
980              If  you  wish  to  inhibit  this  behaviour  entirely,  set  the
981              path-completion style (see below) to `false'.
982
983       add-space
984              This  style  is  used by the _expand completer.  If it is `true'
985              (the default), a space will be inserted after all words  result‐
986              ing  from  the  expansion,  or  a slash in the case of directory
987              names.  If the value is `file', the completer will  only  add  a
988              space  to  names  of existing files.  Either a boolean `true' or
989              the value `file' may be combined with `subst', in which case the
990              completer  will  not add a space to words generated from the ex‐
991              pansion of a substitution of the form `$(...)' or `${...}'.
992
993              The _prefix completer uses this style as a simple boolean  value
994              to decide if a space should be inserted before the suffix.
995
996       ambiguous
997              This  applies  when  completing non-final components of filename
998              paths, in other words those with a trailing  slash.   If  it  is
999              set,  the  cursor  is  left after the first ambiguous component,
1000              even if menu completion is in use.  The style is  always  tested
1001              with the paths tag.
1002
1003       assign-list
1004              When completing after an equals sign that is being treated as an
1005              assignment, the completion system normally  completes  only  one
1006              filename.   In  some cases the value  may be a list of filenames
1007              separated by colons, as with PATH and similar parameters.   This
1008              style  can  be  set  to a list of patterns matching the names of
1009              such parameters.
1010
1011              The default is to complete lists when the word on the  line  al‐
1012              ready contains a colon.
1013
1014       auto-description
1015              If  set,  this style's value will be used as the description for
1016              options that are not described by the completion functions,  but
1017              that  have exactly one argument.  The sequence `%d' in the value
1018              will be replaced by the description for this argument.   Depend‐
1019              ing  on personal preferences, it may be useful to set this style
1020              to something like `specify: %d'.  Note that this  may  not  work
1021              for some commands.
1022
1023       avoid-completer
1024              This  is  used  by  the  _all_matches completer to decide if the
1025              string consisting of all matches should be  added  to  the  list
1026              currently being generated.  Its value is a list of names of com‐
1027              pleters.  If any of these is the name of the completer that gen‐
1028              erated  the  matches  in this completion, the string will not be
1029              added.
1030
1031              The default value for this style is `_expand _old_list  _correct
1032              _approximate',  i.e.  it  contains  the  completers  for which a
1033              string with all matches will almost never be wanted.
1034
1035       cache-path
1036              This style defines the path where  any  cache  files  containing
1037              dumped  completion  data  are  stored.   It  defaults to `$ZDOT‐
1038              DIR/.zcompcache', or `$HOME/.zcompcache' if $ZDOTDIR is not  de‐
1039              fined.   The  completion  cache  will  not  be  used  unless the
1040              use-cache style is set.
1041
1042       cache-policy
1043              This style defines the function that will be used  to  determine
1044              whether  a  cache  needs  rebuilding.   See  the  section on the
1045              _cache_invalid function below.
1046
1047       call-command
1048              This style is used in the function for commands such as make and
1049              ant  where calling the command directly to generate matches suf‐
1050              fers problems such as being slow or, as in the case of make  can
1051              potentially  cause actions in the makefile to be executed. If it
1052              is set to `true' the command is called to generate matches.  The
1053              default value of this style is `false'.
1054
1055       command
1056              In  many places, completion functions need to call external com‐
1057              mands to generate the list of completions.  This  style  can  be
1058              used  to override the command that is called in some such cases.
1059              The elements of the value are joined with spaces to form a  com‐
1060              mand  line  to execute.  The value can also start with a hyphen,
1061              in which case the usual command will be added to the  end;  this
1062              is  most  useful  for putting `builtin' or `command' in front to
1063              make sure the appropriate version of a command  is  called,  for
1064              example  to avoid calling a shell function with the same name as
1065              an external command.
1066
1067              As an example, the completion function for process IDs uses this
1068              style with the processes tag to generate the IDs to complete and
1069              the list of processes  to  display  (if  the  verbose  style  is
1070              `true').   The list produced by the command should look like the
1071              output of the ps command.  The first line is not displayed,  but
1072              is searched for the string `PID' (or `pid') to find the position
1073              of the process IDs in the following lines.  If the line does not
1074              contain  `PID', the first numbers in each of the other lines are
1075              taken as the process IDs to complete.
1076
1077              Note that the completion function  generally  has  to  call  the
1078              specified  command  for  each attempt to generate the completion
1079              list.  Hence care should be taken to specify only commands  that
1080              take  a  short  time to run, and in particular to avoid any that
1081              may never terminate.
1082
1083       command-path
1084              This is a list of directories to search  for  commands  to  com‐
1085              plete.   The  default for this style is the value of the special
1086              parameter path.
1087
1088       commands
1089              This is used by the function  completing  sub-commands  for  the
1090              system  initialisation scripts (residing in /etc/init.d or some‐
1091              where not too far away from that).  Its values give the  default
1092              commands to complete for those commands for which the completion
1093              function isn't able to find them out automatically.  The default
1094              for this style are the two strings `start' and `stop'.
1095
1096       complete
1097              This  is  used  by  the _expand_alias function when invoked as a
1098              bindable command.  If set to `true' and the word on the  command
1099              line  is  not the name of an alias, matching alias names will be
1100              completed.
1101
1102       complete-options
1103              This is used by the completer for  cd,  chdir  and  pushd.   For
1104              these  commands a - is used to introduce a directory stack entry
1105              and completion of these is far more common than  completing  op‐
1106              tions.   Hence  unless the value of this style is `true' options
1107              will not be completed, even  after  an  initial  -.   If  it  is
1108              `true',  options  will  be  completed  after an initial - unless
1109              there is a preceding -- on the command line.
1110
1111       completer
1112              The strings given as the value of this style provide  the  names
1113              of the completer functions to use. The available completer func‐
1114              tions are described in the section `Control Functions' below.
1115
1116              Each string may be either the name of a completer function or  a
1117              string  of the form `function:name'.  In the first case the com‐
1118              pleter field of the context will contain the name  of  the  com‐
1119              pleter  without the leading underscore and with all other under‐
1120              scores replaced by hyphens.  In the second case the function  is
1121              the  name of the completer to call, but the context will contain
1122              the user-defined name in the completer field of the context.  If
1123              the  name  starts with a hyphen, the string for the context will
1124              be build from the name of the completer function as in the first
1125              case with the name appended to it.  For example:
1126
1127                     zstyle ':completion:*' completer _complete _complete:-foo
1128
1129              Here,  completion  will call the _complete completer twice, once
1130              using `complete' and once using `complete-foo' in the  completer
1131              field  of  the context.  Normally, using the same completer more
1132              than once only makes sense when used with  the  `functions:name'
1133              form, because otherwise the context name will be the same in all
1134              calls to the completer; possible exceptions to this rule are the
1135              _ignored and _prefix completers.
1136
1137              The  default  value for this style is `_complete _ignored': only
1138              completion will be done, first using the ignored-patterns  style
1139              and the $fignore array and then without ignoring matches.
1140
1141       condition
1142              This  style is used by the _list completer function to decide if
1143              insertion of matches should be delayed unconditionally. The  de‐
1144              fault is `true'.
1145
1146       delimiters
1147              This  style is used when adding a delimiter for use with history
1148              modifiers or glob qualifiers that have delimited arguments.   It
1149              is an array of preferred delimiters to add.  Non-special charac‐
1150              ters are preferred as the completion system may otherwise become
1151              confused.   The  default list is :, +, /, -, %.  The list may be
1152              empty to force a delimiter to be typed.
1153
1154       disabled
1155              If this is set to `true', the _expand_alias completer and  bind‐
1156              able  command will try to expand disabled aliases, too.  The de‐
1157              fault is `false'.
1158
1159       domains
1160              A list of names of network domains for completion.  If  this  is
1161              not  set,  domain  names  will  be  taken from the file /etc/re‐
1162              solv.conf.
1163
1164       environ
1165              The environ style is used when completing for `sudo'.  It is set
1166              to  an  array of `VAR=value' assignments to be exported into the
1167              local environment before the completion for the  target  command
1168              is invoked.
1169              zstyle ':completion:*:sudo::' environ \
1170                PATH="/sbin:/usr/sbin:$PATH" HOME="/root"
1171
1172       expand This  style is used when completing strings consisting of multi‐
1173              ple parts, such as path names.
1174
1175              If one of its values is the string `prefix', the partially typed
1176              word  from  the line will be expanded as far as possible even if
1177              trailing parts cannot be completed.
1178
1179              If one of its values is the string `suffix', matching names  for
1180              components  after  the  first  ambiguous one will also be added.
1181              This means that the resulting string is the longest  unambiguous
1182              string  possible.  However, menu completion can be used to cycle
1183              through all matches.
1184
1185       extra-verbose
1186              If set, the completion listing is more verbose at the cost of  a
1187              probable  decrease  in completion speed.  Completion performance
1188              will suffer if this style is set to `true'.
1189
1190       fake   This style may be set for any completion context.  It  specifies
1191              additional  strings  that  will always be completed in that con‐
1192              text.  The form of each string is `value:description'; the colon
1193              and  description may be omitted, but any literal colons in value
1194              must be quoted with a backslash.  Any  description  provided  is
1195              shown alongside the value in completion listings.
1196
1197              It  is  important to use a sufficiently restrictive context when
1198              specifying fake strings.  Note that the  styles  fake-files  and
1199              fake-parameters  provide  additional  features  when  completing
1200              files or parameters.
1201
1202       fake-always
1203              This works identically to the fake style  except  that  the  ig‐
1204              nored-patterns style is not applied to it.  This makes it possi‐
1205              ble to override a set of matches completely by setting  the  ig‐
1206              nored patterns to `*'.
1207
1208              The  following  shows  a way of supplementing any tag with arbi‐
1209              trary data, but having it behave for  display  purposes  like  a
1210              separate  tag.   In  this  example  we  use  the features of the
1211              tag-order style to divide the  named-directories  tag  into  two
1212              when  performing completion with the standard completer complete
1213              for arguments of cd.  The tag  named-directories-normal  behaves
1214              as  normal,  but the tag named-directories-mine contains a fixed
1215              set of directories.  This has the effect  of  adding  the  match
1216              group `extra directories' with the given completions.
1217
1218                     zstyle ':completion::complete:cd:*' tag-order \
1219                       'named-directories:-mine:extra\ directories
1220                       named-directories:-normal:named\ directories *'
1221                     zstyle ':completion::complete:cd:*:named-directories-mine' \
1222                       fake-always mydir1 mydir2
1223                     zstyle ':completion::complete:cd:*:named-directories-mine' \
1224                       ignored-patterns '*'
1225
1226       fake-files
1227              This style is used when completing files and looked up without a
1228              tag.  Its values are of the form `dir:names...'.  This will  add
1229              the names (strings separated by spaces) as possible matches when
1230              completing in the directory dir, even if no  such  files  really
1231              exist.   The  dir may be a pattern; pattern characters or colons
1232              in dir should be quoted with a backslash to  be  treated  liter‐
1233              ally.
1234
1235              This  can be useful on systems that support special file systems
1236              whose top-level pathnames can not be listed  or  generated  with
1237              glob  patterns (but see accept-exact-dirs for a more general way
1238              of dealing with this problem).  It can also be used for directo‐
1239              ries for which one does not have read permission.
1240
1241              The  pattern  form can be used to add a certain `magic' entry to
1242              all directories on a particular file system.
1243
1244       fake-parameters
1245              This is used by the completion  function  for  parameter  names.
1246              Its values are names of parameters that might not yet be set but
1247              should be completed nonetheless.  Each name may also be followed
1248              by  a  colon  and  a string specifying the type of the parameter
1249              (like `scalar', `array' or `integer').  If the  type  is  given,
1250              the  name  will only be completed if parameters of that type are
1251              required in the particular context.  Names for which no type  is
1252              specified will always be completed.
1253
1254       file-list
1255              This  style  controls whether files completed using the standard
1256              builtin mechanism are to be listed with a long list  similar  to
1257              ls  -l.   Note  that this feature uses the shell module zsh/stat
1258              for file information; this loads the builtin stat which will re‐
1259              place any external stat executable.  To avoid this the following
1260              code can be included in an initialization file:
1261
1262                     zmodload -i zsh/stat
1263                     disable stat
1264
1265              The style may either be set to a `true' value (or `all'), or one
1266              of  the  values `insert' or `list', indicating that files are to
1267              be listed in long format in all circumstances, or when  attempt‐
1268              ing  to  insert  a file name, or when listing file names without
1269              attempting to insert one.
1270
1271              More generally, the value may be an array of any  of  the  above
1272              values, optionally followed by =num.  If num is present it gives
1273              the maximum number of matches for which long listing style  will
1274              be used.  For example,
1275
1276                     zstyle ':completion:*' file-list list=20 insert=10
1277
1278              specifies  that  long  format will be used when listing up to 20
1279              files or inserting a file with up  to  10  matches  (assuming  a
1280              listing  is to be shown at all, for example on an ambiguous com‐
1281              pletion), else short format will be used.
1282
1283                     zstyle -e ':completion:*' file-list \
1284                            '(( ${+NUMERIC} )) && reply=(true)'
1285
1286              specifies that long format will be used any time a numeric argu‐
1287              ment is supplied, else short format.
1288
1289       file-patterns
1290              This  is used by the standard function for completing filenames,
1291              _files.  If the style is unset up to  three  tags  are  offered,
1292              `globbed-files',`directories'  and `all-files', depending on the
1293              types of files  expected by the caller of _files.  The first two
1294              (`globbed-files'  and  `directories')  are  normally offered to‐
1295              gether to make it easier to complete files in sub-directories.
1296
1297              The file-patterns style provides  alternatives  to  the  default
1298              tags, which are not used.  Its value consists of elements of the
1299              form `pattern:tag'; each string may contain any number  of  such
1300              specifications separated by spaces.
1301
1302              The  pattern  is  a pattern that is to be used to generate file‐
1303              names.  Any occurrence of the sequence `%p' is replaced  by  any
1304              pattern(s) passed by the function calling _files.  Colons in the
1305              pattern must be preceded by a backslash  to  make  them  distin‐
1306              guishable  from the colon before the tag.  If more than one pat‐
1307              tern is needed, the patterns can be given inside  braces,  sepa‐
1308              rated by commas.
1309
1310              The  tags  of all strings in the value will be offered by _files
1311              and used when looking up other styles.  Any  tags  in  the  same
1312              word  will  be  offered at the same time and before later words.
1313              If no `:tag' is given the `files' tag will be used.
1314
1315              The tag may also be followed by an optional second colon  and  a
1316              description, which will be used for the `%d' in the value of the
1317              format style (if that is set) instead of the default description
1318              supplied  by  the  completion  function.  The inclusion of a de‐
1319              scription also gives precedence to associated  options  such  as
1320              for  completion grouping so it can be used where files should be
1321              separated.
1322
1323              For example, to make the rm command first complete only names of
1324              object  files  and  then  the  names of all files if there is no
1325              matching object file:
1326
1327                     zstyle ':completion:*:*:rm:*:*' file-patterns \
1328                         '*.o:object-files' '%p:all-files'
1329
1330              To alter the default behaviour of file completion -- offer files
1331              matching  a  pattern  and directories on the first attempt, then
1332              all files -- to offer only matching files on the first  attempt,
1333              then directories, and finally all files:
1334
1335                     zstyle ':completion:*' file-patterns \
1336                         '%p:globbed-files' '*(-/):directories' '*:all-files'
1337
1338              This  works  even  where  there  is  no  special pattern: _files
1339              matches all files using the pattern `*' at the  first  step  and
1340              stops  when it sees this pattern.  Note also it will never try a
1341              pattern more than once for a single completion attempt.
1342
1343              To separate directories into a separate group from the files but
1344              still complete them at the first attempt, a description needs to
1345              be given.  Note that directories need to be explicitly  excluded
1346              from  the  globbed-files because `*' will match directories. For
1347              grouping, it is also necessary to set the group-name style.
1348
1349                     zstyle ':completion:*' file-patterns \
1350                         '%p(^-/):globbed-files *(-/):directories:location'
1351
1352              During the execution of completion functions, the  EXTENDED_GLOB
1353              option  is  in  effect,  so the characters `#', `~' and `^' have
1354              special meanings in the patterns.
1355
1356       file-sort
1357              The standard filename completion function uses this style  with‐
1358              out  a  tag  to  determine  in  which  order the names should be
1359              listed; menu completion will cycle through them in the same  or‐
1360              der.  The possible values are: `size' to sort by the size of the
1361              file; `links' to sort by the number of links to the file; `modi‐
1362              fication' (or `time' or `date') to sort by the last modification
1363              time; `access' to sort by the last access time; and `inode'  (or
1364              `change')  to  sort by the last inode change time.  If the style
1365              is set to any other value, or is unset, files will be sorted al‐
1366              phabetically  by  name.   If  the value contains the string `re‐
1367              verse', sorting is done in the opposite  order.   If  the  value
1368              contains the string `follow', timestamps are associated with the
1369              targets of symbolic links; the default is to use the  timestamps
1370              of the links themselves.
1371
1372       file-split-chars
1373              A set of characters that will cause all file completions for the
1374              given context to be split at the point where any of the  charac‐
1375              ters  occurs.   A typical use is to set the style to :; then ev‐
1376              erything up to and including the last : in the string so far  is
1377              ignored  when  completing files.  As this is quite heavy-handed,
1378              it is usually preferable to update completion functions for con‐
1379              texts where this behaviour is useful.
1380
1381       filter The  ldap  plugin  of  email  address completion (see _email_ad‐
1382              dresses) uses this style to  specify  the  attributes  to  match
1383              against when filtering entries.  So for example, if the style is
1384              set to `sn', matching is done against surnames.   Standard  LDAP
1385              filtering is used so normal completion matching is bypassed.  If
1386              this style is not set, the LDAP plugin is skipped.  You may also
1387              need  to set the command style to specify how to connect to your
1388              LDAP server.
1389
1390       force-list
1391              This forces a list of completions to be shown at any point where
1392              listing  is  done, even in cases where the list would usually be
1393              suppressed.  For example, normally the list  is  only  shown  if
1394              there are at least two different matches.  By setting this style
1395              to `always', the list will always be shown,  even  if  there  is
1396              only  a  single  match  that  will immediately be accepted.  The
1397              style may also be set to a number.  In this case the  list  will
1398              be  shown  if there are at least that many matches, even if they
1399              would all insert the same string.
1400
1401              This style is tested for the default tag as well as for each tag
1402              valid  for  the  current  completion.   Hence the listing can be
1403              forced only for certain types of match.
1404
1405       format If this is set for the descriptions tag, its value is used as  a
1406              string  to  display  above matches in completion lists.  The se‐
1407              quence `%d' in this string will be replaced  with  a  short  de‐
1408              scription  of what these matches are.  This string may also con‐
1409              tain the output attribute sequences  understood  by  compadd  -X
1410              (see zshcompwid(1)).
1411
1412              The  style is tested with each tag valid for the current comple‐
1413              tion before it is tested for the descriptions tag.   Hence  dif‐
1414              ferent  format  strings  can  be  defined for different types of
1415              match.
1416
1417              Note  also  that  some  completer  functions  define  additional
1418              `%'-sequences.   These are described for the completer functions
1419              that make use of them.
1420
1421              Some completion functions display  messages  that  may  be  cus‐
1422              tomised  by  setting this style for the messages tag.  Here, the
1423              `%d' is replaced with a message given by  the  completion  func‐
1424              tion.
1425
1426              Finally,  the  format string is looked up with the warnings tag,
1427              for use when no matches could be generated at all.  In this case
1428              the  `%d' is replaced with the descriptions for the matches that
1429              were expected separated by spaces.  The  sequence  `%D'  is  re‐
1430              placed with the same descriptions separated by newlines.
1431
1432              It  is  possible to use printf-style field width specifiers with
1433              `%d' and similar escape sequences.  This is handled by the zfor‐
1434              mat  builtin  command  from  the  zsh/zutil  module, see zshmod‐
1435              ules(1).
1436
1437       gain-privileges
1438              If set to true, this style enables the use of commands like sudo
1439              or doas to gain extra privileges when retrieving information for
1440              completion. This is only done when a command such  as  sudo  ap‐
1441              pears  on the command-line. To force the use of, e.g. sudo or to
1442              override any prefix that might be added due to  gain-privileges,
1443              the  command  style  can be used with a value that begins with a
1444              hyphen.
1445
1446       glob   This is used by the _expand completer.  If it is set  to  `true'
1447              (the default), globbing will be attempted on the words resulting
1448              from a previous substitution (see the substitute style) or  else
1449              the original string from the line.
1450
1451       global If  this  is set to `true' (the default), the _expand_alias com‐
1452              pleter and bindable command will try to expand global aliases.
1453
1454       group-name
1455              The completion system can  group  different  types  of  matches,
1456              which  appear in separate lists.  This style can be used to give
1457              the names of groups for particular tags.  For example,  in  com‐
1458              mand  position  the completion system generates names of builtin
1459              and external commands, names of aliases, shell functions and pa‐
1460              rameters  and  reserved  words as possible completions.  To have
1461              the external commands and shell functions listed separately:
1462
1463                     zstyle ':completion:*:*:-command-:*:commands' \
1464                            group-name commands
1465                     zstyle ':completion:*:*:-command-:*:functions' \
1466                            group-name functions
1467
1468              As a consequence, any match with the same tag will be  displayed
1469              in the same group.
1470
1471              If  the  name  given is the empty string the name of the tag for
1472              the matches will be used as the name of the group.  So, to  have
1473              all  different  types  of  matches displayed separately, one can
1474              just set:
1475
1476                     zstyle ':completion:*' group-name ''
1477
1478              All matches for which no group name is defined will be put in  a
1479              group named -default-.
1480
1481              To  display  the  group name in the output, see the format style
1482              (q.v.)  under the descriptions tag.
1483
1484       group-order
1485              This style is additional to the group-name style to specify  the
1486              order  for  display of the groups defined by that style (compare
1487              tag-order, which determines which completions  appear  at  all).
1488              The  groups named are shown in the given order; any other groups
1489              are shown in the order defined by the completion function.
1490
1491              For example, to have names of builtin commands, shell  functions
1492              and  external  commands  appear in that order when completing in
1493              command position:
1494
1495                     zstyle ':completion:*:*:-command-:*:*' group-order \
1496                            builtins functions commands
1497
1498       groups A list of names of UNIX groups.  If this is not set, group names
1499              are taken from the YP database or the file `/etc/group'.
1500
1501       hidden If this is set to `true', matches for the given context will not
1502              be listed, although any description for the matches set with the
1503              format style will be shown.  If it is set to `all', not even the
1504              description will be displayed.
1505
1506              Note that the matches will still be completed; they are just not
1507              shown in the list.  To avoid having matches considered as possi‐
1508              ble completions at all, the tag-order style can be  modified  as
1509              described below.
1510
1511       hosts  A  list  of names of hosts that should be completed.  If this is
1512              not set, hostnames are taken from the file `/etc/hosts'.
1513
1514       hosts-ports
1515              This style is used by commands that need or accept hostnames and
1516              network  ports.   The strings in the value should be of the form
1517              `host:port'.  Valid ports are  determined  by  the  presence  of
1518              hostnames; multiple ports for the same host may appear.
1519
1520       ignore-line
1521              This  is  tested  for each tag valid for the current completion.
1522              If it is set to `true', none of the words that  are  already  on
1523              the  line  will be considered as possible completions.  If it is
1524              set to `current', the word the cursor is on will not be  consid‐
1525              ered  as  a  possible  completion.  The value `current-shown' is
1526              similar but only applies if the list of completions is currently
1527              shown  on  the screen.  Finally, if the style is set to `other',
1528              all words on the line except for the current  one  will  be  ex‐
1529              cluded from the possible completions.
1530
1531              The  values `current' and `current-shown' are a bit like the op‐
1532              posite of the accept-exact style:   only  strings  with  missing
1533              characters will be completed.
1534
1535              Note  that you almost certainly don't want to set this to `true'
1536              or `other' for a general context such as `:completion:*'.   This
1537              is because it would disallow completion of, for example, options
1538              multiple times even if the command in question accepts  the  op‐
1539              tion more than once.
1540
1541       ignore-parents
1542              The  style  is  tested  without a tag by the function completing
1543              pathnames in order to determine whether to ignore the  names  of
1544              directories  already  mentioned in the current word, or the name
1545              of the current working directory.  The value must include one or
1546              both of the following strings:
1547
1548              parent The name of any directory whose path is already contained
1549                     in the word on the line is ignored.   For  example,  when
1550                     completing  after  foo/../, the directory foo will not be
1551                     considered a valid completion.
1552
1553              pwd    The name of the current working  directory  will  not  be
1554                     completed;  hence, for example, completion after ../ will
1555                     not use the name of the current directory.
1556
1557              In addition, the value may include one or both of:
1558
1559              ..     Ignore the specified directories only when  the  word  on
1560                     the line contains the substring `../'.
1561
1562              directory
1563                     Ignore  the  specified directories only when names of di‐
1564                     rectories are completed, not  when  completing  names  of
1565                     files.
1566
1567              Excluded  values  act  in a similar fashion to values of the ig‐
1568              nored-patterns style, so they can be restored  to  consideration
1569              by the _ignored completer.
1570
1571       ignored-patterns
1572              A  list  of  patterns;  any trial completion matching one of the
1573              patterns will be excluded from consideration.  The _ignored com‐
1574              pleter  can  appear in the list of completers to restore the ig‐
1575              nored matches.  This is a more configurable version of the shell
1576              parameter $fignore.
1577
1578              Note  that  the EXTENDED_GLOB option is set during the execution
1579              of completion functions, so the characters `#', `~' and `^' have
1580              special meanings in the patterns.
1581
1582       insert This  style  is  used  by  the  _all_matches completer to decide
1583              whether to insert the list of all  matches  unconditionally  in‐
1584              stead of adding the list as another match.
1585
1586       insert-ids
1587              When  completing  process  IDs,  for example as arguments to the
1588              kill and wait builtins the name of a command may be converted to
1589              the  appropriate  process ID.  A problem arises when the process
1590              name typed is not unique.  By default (or if this style  is  set
1591              explicitly  to `menu') the name will be converted immediately to
1592              a set of possible IDs, and menu completion will  be  started  to
1593              cycle through them.
1594
1595              If the value of the style is `single', the shell will wait until
1596              the user has typed enough to make the command unique before con‐
1597              verting the name to an ID; attempts at completion will be unsuc‐
1598              cessful until that point.  If the value  is  any  other  string,
1599              menu  completion  will  be  started when the string typed by the
1600              user is longer than the common prefix to the corresponding IDs.
1601
1602       insert-sections
1603              This style is used with tags of the form `manuals.X'  when  com‐
1604              pleting  names of manual pages. If set and the X in the tag name
1605              matches the section number of the page being completed, the sec‐
1606              tion  number  is inserted along with the page name. For example,
1607              given
1608
1609                     zstyle ':completion:*:manuals.*' insert-sections true
1610
1611              man ssh_<TAB> may be completed to man 5 ssh_config.
1612
1613              The value may also be set to  one  of  `prepend',  or  `suffix'.
1614              `prepend'  behaves  the  same as `true' as in the above example,
1615              while `suffix' would complete man ssh_<TAB> as man ssh_config.5.
1616
1617              This is especially useful in conjunction with separate-sections,
1618              as  it ensures that the page requested of man corresponds to the
1619              one displayed in the completion listing when there are  multiple
1620              pages with the same name (e.g., printf(1) and printf(3)).
1621
1622              The default for this style is `false'.
1623
1624       insert-tab
1625              If  this  is  set to `true', the completion system will insert a
1626              TAB character (assuming that was used to start  completion)  in‐
1627              stead  of performing completion when there is no non-blank char‐
1628              acter to the left of the cursor.  If it is set to `false',  com‐
1629              pletion will be done even there.
1630
1631              The  value  may  also contain the substrings `pending' or `pend‐
1632              ing=val'.  In this case, the typed character  will  be  inserted
1633              instead  of  starting completion when there is unprocessed input
1634              pending.  If a val is given, completion  will  not  be  done  if
1635              there  are  at  least that many characters of unprocessed input.
1636              This is often useful when pasting characters  into  a  terminal.
1637              Note  however,  that it relies on the $PENDING special parameter
1638              from the zsh/zle module being set properly which is not  guaran‐
1639              teed on all platforms.
1640
1641              The  default value of this style is `true' except for completion
1642              within vared builtin command where it is `false'.
1643
1644       insert-unambiguous
1645              This is used by the _match and _approximate  completers.   These
1646              completers  are  often  used with menu completion since the word
1647              typed may bear little resemblance to the final completion.  How‐
1648              ever,  if  this  style  is `true', the completer will start menu
1649              completion only if it could find no unambiguous  initial  string
1650              at least as long as the original string typed by the user.
1651
1652              In  the  case of the _approximate completer, the completer field
1653              in the context will already have been set to one of  correct-num
1654              or  approximate-num, where num is the number of errors that were
1655              accepted.
1656
1657              In the case of the _match completer, the style may also  be  set
1658              to  the  string `pattern'.  Then the pattern on the line is left
1659              unchanged if it does not match unambiguously.
1660
1661       keep-prefix
1662              This style is used by the _expand completer.  If it  is  `true',
1663              the  completer  will  try to keep a prefix containing a tilde or
1664              parameter expansion.  Hence,  for  example,  the  string  `~/f*'
1665              would  be  expanded  to `~/foo' instead of `/home/user/foo'.  If
1666              the style is set to `changed' (the  default),  the  prefix  will
1667              only  be  left unchanged if there were other changes between the
1668              expanded words and the original word from the command line.  Any
1669              other value forces the prefix to be expanded unconditionally.
1670
1671              The  behaviour  of _expand when this style is `true' is to cause
1672              _expand to give up when a single  expansion  with  the  restored
1673              prefix  is  the  same  as the original; hence any remaining com‐
1674              pleters may be called.
1675
1676       known-hosts-files
1677              This style should contain a list of files  to  search  for  host
1678              names  and (if the use-ip style is set) IP addresses in a format
1679              compatible with ssh known_hosts files.  If it is  not  set,  the
1680              files /etc/ssh/ssh_known_hosts and ~/.ssh/known_hosts are used.
1681
1682       last-prompt
1683              This  is  a more flexible form of the ALWAYS_LAST_PROMPT option.
1684              If it is `true', the completion system will try  to  return  the
1685              cursor  to  the previous command line after displaying a comple‐
1686              tion list.  It is tested for all tags valid for the current com‐
1687              pletion, then the default tag.  The cursor will be moved back to
1688              the previous line if this style  is  `true'  for  all  types  of
1689              match.   Note  that unlike the ALWAYS_LAST_PROMPT option this is
1690              independent of the numeric argument.
1691
1692       list   This style is used by the _history_complete_word  bindable  com‐
1693              mand.  If it is set to `true' it has no effect.  If it is set to
1694              `false' matches will not be listed.  This overrides the  setting
1695              of  the  options  controlling  listing  behaviour, in particular
1696              AUTO_LIST.  The context  always  starts  with  `:completion:his‐
1697              tory-words'.
1698
1699       list-colors
1700              If  the zsh/complist module is loaded, this style can be used to
1701              set color specifications.  This mechanism replaces  the  use  of
1702              the  ZLS_COLORS and ZLS_COLOURS parameters described in the sec‐
1703              tion `The zsh/complist Module' in zshmodules(1), but the  syntax
1704              is the same.
1705
1706              If  this  style  is  set for the default tag, the strings in the
1707              value are taken as specifications that are  to  be  used  every‐
1708              where.  If it is set for other tags, the specifications are used
1709              only for matches of the type described by the tag.  For this  to
1710              work best, the group-name style must be set to an empty string.
1711
1712              In addition to setting styles for specific tags, it is also pos‐
1713              sible to use group names specified explicitly by the  group-name
1714              tag together with the `(group)' syntax allowed by the ZLS_COLORS
1715              and ZLS_COLOURS parameters and simply using the default tag.
1716
1717              It is possible to use any color specifications  already  set  up
1718              for the GNU version of the ls command:
1719
1720                     zstyle ':completion:*:default' list-colors \
1721                            ${(s.:.)LS_COLORS}
1722
1723              The  default  colors  are the same as for the GNU ls command and
1724              can be obtained by setting the style to an  empty  string  (i.e.
1725              '').
1726
1727       list-dirs-first
1728              This  is used by file completion and corresponds to a particular
1729              setting of the file-patterns style.  If set, the default  direc‐
1730              tories  to  be  completed  are listed separately from and before
1731              completion for other files.
1732
1733       list-grouped
1734              If this style is `true' (the  default),  the  completion  system
1735              will  try  to  make  certain completion listings more compact by
1736              grouping matches.  For example, options for commands  that  have
1737              the  same  description  (shown  when the verbose style is set to
1738              `true') will appear as a single entry.  However, menu  selection
1739              can be used to cycle through all the matches.
1740
1741       list-packed
1742              This is tested for each tag valid in the current context as well
1743              as the default tag.  If it is set to `true',  the  corresponding
1744              matches  appear  in  listings  as if the LIST_PACKED option were
1745              set.  If it is set to `false', they are listed normally.
1746
1747       list-prompt
1748              If this style is set for the default tag, completion lists  that
1749              don't  fit on the screen can be scrolled (see the description of
1750              the zsh/complist module in zshmodules(1)).  The  value,  if  not
1751              the  empty  string,  will be displayed after every screenful and
1752              the shell will prompt for a key press; if the style  is  set  to
1753              the empty string, a default prompt will be used.
1754
1755              The  value may contain the escape sequences: `%l' or `%L', which
1756              will be replaced by the number of the last  line  displayed  and
1757              the total number of lines; `%m' or `%M', the number of the  last
1758              match shown and the total number of matches; and `%p' and  `%P',
1759              `Top'  when  at  the beginning of the list, `Bottom' when at the
1760              end and the position shown as a percentage of the  total  length
1761              otherwise.  In each case the form with the uppercase letter will
1762              be replaced by a string of fixed width,  padded  to  the   right
1763              with  spaces,  while  the  lowercase  form will be replaced by a
1764              variable width string.  As in other prompt strings,  the  escape
1765              sequences  `%S',  `%s',  `%B', `%b', `%U', `%u' for entering and
1766              leaving the display modes  standout,  bold  and  underline,  and
1767              `%F',  `%f',  `%K',  `%k' for changing the foreground background
1768              colour, are also available, as is the form `%{...%}' for enclos‐
1769              ing escape sequences which display with zero (or, with a numeric
1770              argument, some other) width.
1771
1772              After deleting this prompt the variable LISTPROMPT should be un‐
1773              set for the removal to take effect.
1774
1775       list-rows-first
1776              This  style  is  tested in the same way as the list-packed style
1777              and determines whether matches are to be listed in a  rows-first
1778              fashion as if the LIST_ROWS_FIRST option were set.
1779
1780       list-separator
1781              The  value  of this style is used in completion listing to sepa‐
1782              rate the string to complete from  a  description  when  possible
1783              (e.g.  when  completing  options).  It defaults to `--' (two hy‐
1784              phens).
1785
1786       list-suffixes
1787              This style is used by the function that completes filenames.  If
1788              it is `true', and completion is attempted on a string containing
1789              multiple partially typed pathname components, all ambiguous com‐
1790              ponents will be shown.  Otherwise, completion stops at the first
1791              ambiguous component.
1792
1793       local  This is for use with functions that complete URLs for which  the
1794              corresponding files are available directly from the file system.
1795              Its value should consist of three strings: a hostname, the  path
1796              to  the default web pages for the server, and the directory name
1797              used by a user placing web pages within their home area.
1798
1799              For example:
1800
1801                     zstyle ':completion:*' local toast \
1802                         /var/http/public/toast public_html
1803
1804              Completion after `http://toast/stuff/' will look  for  files  in
1805              the  directory  /var/http/public/toast/stuff,   while completion
1806              after `http://toast/~yousir/' will look for files in the  direc‐
1807              tory ~yousir/public_html.
1808
1809       mail-directory
1810              If  set,  zsh will assume that mailbox files can be found in the
1811              directory specified.  It defaults to `~/Mail'.
1812
1813       match-original
1814              This is used by the _match completer.  If it  is  set  to  only,
1815              _match  will  try to generate matches without inserting a `*' at
1816              the cursor position.  If set to any other  non-empty  value,  it
1817              will first try to generate matches without inserting the `*' and
1818              if that yields no matches, it will try again with  the  `*'  in‐
1819              serted.   If  it  is  unset or set to the empty string, matching
1820              will only be performed with the `*' inserted.
1821
1822       matcher
1823              This style is tested separately for each tag valid in  the  cur‐
1824              rent  context.   Its value is placed before any match specifica‐
1825              tions given by the matcher-list style so can override  them  via
1826              the use of an x: specification.  The value should be in the form
1827              described in the section `Completion Matching Control'  in  zsh‐
1828              compwid(1).   For  examples  of this, see the description of the
1829              tag-order style.
1830
1831              For notes comparing the use of this and the matcher-list  style,
1832              see under the description of the tag-order style.
1833
1834       matcher-list
1835              This style can be set to a list of match specifications that are
1836              to be applied everywhere. Match specifications are described  in
1837              the section `Completion Matching Control' in zshcompwid(1).  The
1838              completion system will try them one after another for each  com‐
1839              pleter  selected.   For  example, to try first simple completion
1840              and, if that generates no matches, case-insensitive completion:
1841
1842                     zstyle ':completion:*' matcher-list '' 'm:{a-zA-Z}={A-Za-z}'
1843
1844              By default each specification replaces the  previous  one;  how‐
1845              ever,  if a specification is prefixed with +, it is added to the
1846              existing list.  Hence it is possible to create increasingly gen‐
1847              eral specifications without repetition:
1848
1849                     zstyle ':completion:*' matcher-list \
1850                            '' '+m:{a-z}={A-Z}' '+m:{A-Z}={a-z}'
1851
1852              It is possible to create match specifications valid for particu‐
1853              lar completers by using the third field of  the  context.   This
1854              applies   only   to   completers   that   override   the  global
1855              matcher-list, which as of this writing includes only _prefix and
1856              _ignored.   For  example,  to  use  the completers _complete and
1857              _prefix but allow case-insensitive completion  only  with  _com‐
1858              plete:
1859
1860                     zstyle ':completion:*' completer _complete _prefix
1861                     zstyle ':completion:*:complete:*:*:*' matcher-list \
1862                            '' 'm:{a-zA-Z}={A-Za-z}'
1863
1864              User-defined  names,  as  explained for the completer style, are
1865              available.  This makes it possible to  try  the  same  completer
1866              more  than  once  with different match specifications each time.
1867              For example, to try normal completion without a match specifica‐
1868              tion,  then  normal  completion  with case-insensitive matching,
1869              then correction, and finally partial-word completion:
1870
1871                     zstyle ':completion:*' completer \
1872                         _complete _correct _complete:foo
1873                     zstyle ':completion:*:complete:*:*:*' matcher-list \
1874                         '' 'm:{a-zA-Z}={A-Za-z}'
1875                     zstyle ':completion:*:foo:*:*:*' matcher-list \
1876                         'm:{a-zA-Z}={A-Za-z} r:|[-_./]=* r:|=*'
1877
1878              If the style is unset in any context no match  specification  is
1879              applied.   Note  also  that some completers such as _correct and
1880              _approximate do not use the match specifications at all,  though
1881              these  completers  will  only  ever  be  called once even if the
1882              matcher-list contains more than one element.
1883
1884              Where multiple specifications are useful, note that  the  entire
1885              completion  is  done for each element of matcher-list, which can
1886              quickly reduce the shell's performance.   As  a  rough  rule  of
1887              thumb,  one  to  three strings will give acceptable performance.
1888              On the other hand, putting multiple space-separated values  into
1889              the  same  string does not have an appreciable impact on perfor‐
1890              mance.
1891
1892              If there is no current matcher or it is empty,  and  the  option
1893              NO_CASE_GLOB  is  in effect, the matching for files is performed
1894              case-insensitively in any case.  However, any matcher  must  ex‐
1895              plicitly specify case-insensitive matching if that is required.
1896
1897              For  notes  comparing the use of this and the matcher style, see
1898              under the description of the tag-order style.
1899
1900       max-errors
1901              This is used by the _approximate and  _correct  completer  func‐
1902              tions  to  determine the maximum number of errors to allow.  The
1903              completer will try to generate completions by first allowing one
1904              error,  then  two  errors,  and  so  on, until either a match or
1905              matches were found or the maximum number of errors given by this
1906              style has been reached.
1907
1908              If  the  value for this style contains the string `numeric', the
1909              completer function will take any numeric argument as the maximum
1910              number of errors allowed. For example, with
1911
1912                     zstyle ':completion:*:approximate:::' max-errors 2 numeric
1913
1914              two errors are allowed if no numeric argument is given, but with
1915              a numeric argument of six (as in `ESC-6 TAB'), up to six  errors
1916              are  accepted.  Hence with a value of `0 numeric', no correcting
1917              completion will be attempted unless a numeric argument is given.
1918
1919              If the value contains the string  `not-numeric',  the  completer
1920              will  not try to generate corrected completions when given a nu‐
1921              meric argument, so in this  case  the  number  given  should  be
1922              greater  than zero.  For example, `2 not-numeric' specifies that
1923              correcting completion with two errors will usually be performed,
1924              but  if  a numeric argument is given, correcting completion will
1925              not be performed.
1926
1927              The default value for this style is `2 numeric'.
1928
1929       max-matches-width
1930              This style is used to determine the trade off between the  width
1931              of the display used for matches and the width used for their de‐
1932              scriptions when the verbose style is in effect.  The value gives
1933              the  number  of display columns to reserve for the matches.  The
1934              default is half the width of the screen.
1935
1936              This has the most impact when several matches have the same  de‐
1937              scription and so will be grouped together.  Increasing the style
1938              will allow more matches to be grouped  together;  decreasing  it
1939              will allow more of the description to be visible.
1940
1941       menu   If  this is `true' in the context of any of the tags defined for
1942              the current completion menu completion will be used.  The  value
1943              for  a  specific tag will take precedence over that for the `de‐
1944              fault' tag.
1945
1946              If none of the values found in this way is `true' but  at  least
1947              one  is set to `auto', the shell behaves as if the AUTO_MENU op‐
1948              tion is set.
1949
1950              If one of the values is explicitly set to `false', menu  comple‐
1951              tion will be explicitly turned off, overriding the MENU_COMPLETE
1952              option and other settings.
1953
1954              In the form `yes=num', where `yes' may be any of the `true' val‐
1955              ues  (`yes',  `true',  `on'  and  `1'),  menu completion will be
1956              turned on if there are  at  least  num  matches.   In  the  form
1957              `yes=long',  menu  completion will be turned on if the list does
1958              not fit on the screen.  This does not activate  menu  completion
1959              if  the widget normally only lists completions, but menu comple‐
1960              tion  can  be  activated   in   that   case   with   the   value
1961              `yes=long-list'  (Typically,  the  value  `select=long-list' de‐
1962              scribed later  is  more  useful  as  it  provides  control  over
1963              scrolling.)
1964
1965              Similarly,  with any of the `false' values (as in `no=10'), menu
1966              completion will not be used if there are num or more matches.
1967
1968              The value of this widget also controls menu selection, as imple‐
1969              mented by the zsh/complist module.  The following values may ap‐
1970              pear either alongside or instead of the values above.
1971
1972              If the value contains the string `select', menu  selection  will
1973              be started unconditionally.
1974
1975              In the form `select=num', menu selection will only be started if
1976              there are at least num matches.  If the values for more than one
1977              tag provide a number, the smallest number is taken.
1978
1979              Menu  selection can be turned off explicitly by defining a value
1980              containing the string`no-select'.
1981
1982              It is also possible to start menu selection only if the list  of
1983              matches  does  not  fit  on  the  screen by using the value `se‐
1984              lect=long'.  To start menu selection even if the current  widget
1985              only performs listing, use the value `select=long-list'.
1986
1987              To  turn  on  menu completion or menu selection when there are a
1988              certain number of matches or the list of matches does not fit on
1989              the  screen,  both  of  `yes=' and `select=' may be given twice,
1990              once with a number and once with `long' or `long-list'.
1991
1992              Finally, it is possible to activate two special  modes  of  menu
1993              selection.   The word `interactive' in the value causes interac‐
1994              tive mode to be  entered  immediately  when  menu  selection  is
1995              started;  see the description of the zsh/complist module in zsh‐
1996              modules(1) for a description of interactive mode.  Including the
1997              string  `search'  does the same for incremental search mode.  To
1998              select  backward  incremental   search,   include   the   string
1999              `search-backward'.
2000
2001       muttrc If  set,  gives the location of the mutt configuration file.  It
2002              defaults to `~/.muttrc'.
2003
2004       numbers
2005              This is used with the jobs tag.  If it is `true', the shell will
2006              complete  job numbers instead of the shortest unambiguous prefix
2007              of the job command text.  If the value is a number, job  numbers
2008              will  only  be used if that many words from the job descriptions
2009              are required to resolve ambiguities.  For example, if the  value
2010              is  `1',  strings  will  only  be used if all jobs differ in the
2011              first word on their command lines.
2012
2013       old-list
2014              This is used by the _oldlist completer.  If it is  set  to  `al‐
2015              ways',  then  standard widgets which perform listing will retain
2016              the current list of matches, however they were  generated;  this
2017              can  be turned off explicitly with the value `never', giving the
2018              behaviour without the _oldlist completer.  If the style  is  un‐
2019              set,  or  any other value, then the existing list of completions
2020              is displayed if it is not already; otherwise, the standard  com‐
2021              pletion  list  is  generated;  this  is the default behaviour of
2022              _oldlist.  However, if there is an old list and this style  con‐
2023              tains  the  name  of  the  completer function that generated the
2024              list, then the old list will be used even if it was generated by
2025              a widget which does not do listing.
2026
2027              For  example, suppose you type ^Xc to use the _correct_word wid‐
2028              get, which generates a list of corrections for  the  word  under
2029              the  cursor.   Usually, typing ^D would generate a standard list
2030              of completions for the word on the command line, and show  that.
2031              With  _oldlist, it will instead show the list of corrections al‐
2032              ready generated.
2033
2034              As another example consider the _match completer: with  the  in‐
2035              sert-unambiguous  style  set  to `true' it inserts only a common
2036              prefix string, if there is any.  However, this may remove  parts
2037              of  the  original pattern, so that further completion could pro‐
2038              duce more matches than on  the  first  attempt.   By  using  the
2039              _oldlist completer and setting this style to _match, the list of
2040              matches generated on the first attempt will be used again.
2041
2042       old-matches
2043              This is used by the _all_matches completer to decide if  an  old
2044              list  of matches should be used if one exists.  This is selected
2045              by one of the `true' values or by the  string  `only'.   If  the
2046              value  is  `only',  _all_matches  will  only use an old list and
2047              won't have any effect on the list  of  matches  currently  being
2048              generated.
2049
2050              If  this  style  is  set  it  is  generally  unwise  to call the
2051              _all_matches completer unconditionally.  One possible use is for
2052              either  this style or the completer style to be defined with the
2053              -e option to zstyle to make the style conditional.
2054
2055       old-menu
2056              This is used by the _oldlist completer.  It  controls  how  menu
2057              completion  behaves  when a completion has already been inserted
2058              and the user types a standard completion key such as  TAB.   The
2059              default  behaviour  of  _oldlist  is that menu completion always
2060              continues with the existing list of completions.  If this  style
2061              is  set  to `false', however, a new completion is started if the
2062              old list was generated by a different completion  command;  this
2063              is the behaviour without the _oldlist completer.
2064
2065              For  example, suppose you type ^Xc to generate a list of correc‐
2066              tions, and menu completion is started in one of the usual  ways.
2067              Usually,  or  with this style set to `false', typing TAB at this
2068              point would start trying to complete the line as it now appears.
2069              With _oldlist, it instead continues to cycle through the list of
2070              corrections.
2071
2072       original
2073              This is used by the _approximate and _correct completers to  de‐
2074              cide  if  the original string should be added as a possible com‐
2075              pletion.  Normally, this is done only if there are at least  two
2076              possible  corrections, but if this style is set to `true', it is
2077              always added.  Note that the style will  be  examined  with  the
2078              completer  field  in  the context name set to correct-num or ap‐
2079              proximate-num, where num is the number of errors that  were  ac‐
2080              cepted.
2081
2082       packageset
2083              This  style  is  used  when  completing  arguments of the Debian
2084              `dpkg' program.  It contains an override for the default package
2085              set for a given context.  For example,
2086
2087                     zstyle ':completion:*:complete:dpkg:option--status-1:*' \
2088                                    packageset avail
2089
2090              causes  available packages, rather than only installed packages,
2091              to be completed for `dpkg --status'.
2092
2093       path   The function that completes color names uses this style with the
2094              colors tag.  The value should be the pathname of a file contain‐
2095              ing color names in the format of an X11 rgb.txt  file.   If  the
2096              style  is not set but this file is found in one of various stan‐
2097              dard locations it will be used as the default.
2098
2099       path-completion
2100              This is used by filename completion.  By default, filename  com‐
2101              pletion  examines  all  components of a path to see if there are
2102              completions of that component.  For example, /u/b/z can be  com‐
2103              pleted  to  /usr/bin/zsh.   Explicitly  setting  this  style  to
2104              `false' inhibits this behaviour for path components up to the  /
2105              before  the  cursor;  this  overrides  the setting of accept-ex‐
2106              act-dirs.
2107
2108              Even with the style set to `false', it is still possible to com‐
2109              plete  multiple paths by setting the option COMPLETE_IN_WORD and
2110              moving the cursor back to the first component in the path to  be
2111              completed.  For example, /u/b/z can be completed to /usr/bin/zsh
2112              if the cursor is after the /u.
2113
2114       pine-directory
2115              If set, specifies the directory containing PINE  mailbox  files.
2116              There  is no default, since recursively searching this directory
2117              is inconvenient for anyone who doesn't use PINE.
2118
2119       ports  A list of Internet service names (network  ports)  to  complete.
2120              If  this  is  not  set,  service  names  are taken from the file
2121              `/etc/services'.
2122
2123       prefix-hidden
2124              This is used for certain completions which share a  common  pre‐
2125              fix,  for  example command options beginning with dashes.  If it
2126              is `true', the prefix will not be shown in the list of matches.
2127
2128              The default value for this style is `false'.
2129
2130       prefix-needed
2131              This style is also relevant for matches with  a  common  prefix.
2132              If  it  is set to `true' this common prefix must be typed by the
2133              user to generate the matches.
2134
2135              The style is applicable to the  options,  signals,  jobs,  func‐
2136              tions, and parameters completion tags.
2137
2138              For  command  options,  this means that the initial `-', `+', or
2139              `--' must be typed explicitly before option names will  be  com‐
2140              pleted.
2141
2142              For signals, an initial `-' is required before signal names will
2143              be completed.
2144
2145              For jobs, an initial `%' is required before job  names  will  be
2146              completed.
2147
2148              For  function  and parameter names, an initial `_' or `.' is re‐
2149              quired before function or parameter names  starting  with  those
2150              characters will be completed.
2151
2152              The default value for this style is `false' for function and pa‐
2153              rameter completions, and  `true' otherwise.
2154
2155       preserve-prefix
2156              This style is used when completing path names.  Its value should
2157              be  a pattern matching an initial prefix of the word to complete
2158              that should be left unchanged under all circumstances.  For  ex‐
2159              ample,  on some Unices an initial `//' (double slash) has a spe‐
2160              cial meaning; setting this style to the string  `//'  will  pre‐
2161              serve it.  As another example, setting this style to `?:/' under
2162              Cygwin would allow completion after `a:/...' and so on.
2163
2164       range  This is used by the _history  completer  and  the  _history_com‐
2165              plete_word bindable command to decide which words should be com‐
2166              pleted.
2167
2168              If it is a single number, only the last N words from the history
2169              will be completed.
2170
2171              If  it  is a range of the form `max:slice', the last slice words
2172              will be completed; then if that yields  no  matches,  the  slice
2173              words  before those will be tried and so on.  This process stops
2174              either when at least one match has been found, or max words have
2175              been tried.
2176
2177              The default is to complete all words from the history at once.
2178
2179       recursive-files
2180              If  this  style  is set, its value is an array of patterns to be
2181              tested against `$PWD/': note the trailing  slash,  which  allows
2182              directories  in the pattern to be delimited unambiguously by in‐
2183              cluding slashes on both sides.  If an ordinary  file  completion
2184              fails  and  the word on the command line does not yet have a di‐
2185              rectory part to its name, the style is retrieved using the  same
2186              tag  as  for  the  completion  just attempted, then the elements
2187              tested against $PWD/ in turn.  If one matches,  then  the  shell
2188              reattempts completion by prepending the word on the command line
2189              with each directory in the expansion of **/*(/) in turn.   Typi‐
2190              cally the elements of the style will be set to restrict the num‐
2191              ber of directories beneath the current one to a manageable  num‐
2192              ber, for example `*/.git/*'.
2193
2194              For example,
2195
2196                     zstyle ':completion:*' recursive-files '*/zsh/*'
2197
2198              If  the current directory is /home/pws/zsh/Src, then zle_tr<TAB>
2199              can be completed to Zle/zle_tricky.c.
2200
2201       regular
2202              This style is used by the _expand_alias completer  and  bindable
2203              command.   If  set to `true' (the default), regular aliases will
2204              be expanded but only in command  position.   If  it  is  set  to
2205              `false',  regular aliases will never be expanded.   If it is set
2206              to `always', regular aliases will be expanded  even  if  not  in
2207              command position.
2208
2209       rehash If  this  is set when completing external commands, the internal
2210              list (hash) of commands will be updated for each search by issu‐
2211              ing the rehash command.  There is a speed penalty for this which
2212              is only likely to be noticeable when  directories  in  the  path
2213              have slow file access.
2214
2215       remote-access
2216              If  set to `false', certain commands will be prevented from mak‐
2217              ing Internet connections to retrieve remote  information.   This
2218              includes the completion for the CVS command.
2219
2220              It  is not always possible to know if connections are in fact to
2221              a remote site, so some may be prevented unnecessarily.
2222
2223       remove-all-dups
2224              The _history_complete_word bindable  command  and  the  _history
2225              completer  use this to decide if all duplicate matches should be
2226              removed, rather than just consecutive duplicates.
2227
2228       select-prompt
2229              If this is set for the default tag, its value will be  displayed
2230              during  menu  selection (see the menu style above) when the com‐
2231              pletion list does not fit on the screen as a  whole.   The  same
2232              escapes as for the list-prompt style are understood, except that
2233              the numbers refer to the match or line the mark is  on.   A  de‐
2234              fault prompt is used when the value is the empty string.
2235
2236       select-scroll
2237              This  style  is  tested for the default tag and determines how a
2238              completion list is scrolled during a  menu  selection  (see  the
2239              menu  style  above) when the completion list does not fit on the
2240              screen as a whole.  If the value is  `0'  (zero),  the  list  is
2241              scrolled  by  half-screenfuls;  if it is a positive integer, the
2242              list is scrolled by the given number of lines; if it is a  nega‐
2243              tive number, the list is scrolled by a screenful minus the abso‐
2244              lute value of the given number of  lines.   The  default  is  to
2245              scroll by single lines.
2246
2247       separate-sections
2248              This style is used with the manuals tag when completing names of
2249              manual pages.  If it is `true', entries for  different  sections
2250              are  added  separately  using tag names of the form `manuals.X',
2251              where X is the section number.  When  the  group-name  style  is
2252              also  in effect, pages from different sections will appear sepa‐
2253              rately.  This style is also used similarly with the words  style
2254              when completing words for the dict command. It allows words from
2255              different dictionary databases to be added separately. See  also
2256              insert-sections.
2257
2258              The default for this style is `false'.
2259
2260       show-ambiguity
2261              If  the zsh/complist module is loaded, this style can be used to
2262              highlight the first ambiguous character in completion lists. The
2263              value  is  either  a color indication such as those supported by
2264              the list-colors style or, with a value of `true', a  default  of
2265              underlining is selected. The highlighting is only applied if the
2266              completion display strings correspond to the actual matches.
2267
2268       show-completer
2269              Tested whenever a new completer is tried.  If it is `true',  the
2270              completion system outputs a progress message in the listing area
2271              showing what completer is being  tried.   The  message  will  be
2272              overwritten  by any output when completions are found and is re‐
2273              moved after completion is finished.
2274
2275       single-ignored
2276              This is used by the _ignored completer when there  is  only  one
2277              match.   If  its  value is `show', the single match will be dis‐
2278              played but not inserted.  If the value is `menu', then the  sin‐
2279              gle  match and the original string are both added as matches and
2280              menu completion is started, making it easy to select  either  of
2281              them.
2282
2283       sort   This allows the standard ordering of matches to be overridden.
2284
2285              If  its  value  is `true' or `false', sorting is enabled or dis‐
2286              abled.  Additionally the values associated with the `-o'  option
2287              to  compadd can also be listed: match, nosort, numeric, reverse.
2288              If it is not set for the context, the standard behaviour of  the
2289              calling widget is used.
2290
2291              The style is tested first against the full context including the
2292              tag, and if that fails to produce a value  against  the  context
2293              without the tag.
2294
2295              In  many  cases where a calling widget explicitly selects a par‐
2296              ticular ordering in lieu of the default, a value  of  `true'  is
2297              not  honoured.   An example of where this is not the case is for
2298              command history where the default of sorting matches chronologi‐
2299              cally may be overridden by setting the style to `true'.
2300
2301              In the _expand completer, if it is set to `true', the expansions
2302              generated will always be sorted.  If it is set to  `menu',  then
2303              the  expansions  are only sorted when they are offered as single
2304              strings but not in the string  containing  all  possible  expan‐
2305              sions.
2306
2307       special-dirs
2308              Normally,  the  completion  code  will not produce the directory
2309              names `.' and `..' as possible completions.  If  this  style  is
2310              set to `true', it will add both `.' and `..' as possible comple‐
2311              tions; if it is set to `..', only `..' will be added.
2312
2313              The following example sets special-dirs to `..' when the current
2314              prefix is empty, is a single `.', or consists only of a path be‐
2315              ginning with `../'.  Otherwise the value is `false'.
2316
2317                     zstyle -e ':completion:*' special-dirs \
2318                        '[[ $PREFIX = (../)#(|.|..) ]] && reply=(..)'
2319
2320       squeeze-slashes
2321              If set to `true', sequences of slashes in  filename  paths  (for
2322              example  in `foo//bar') will be treated as a single slash.  This
2323              is the usual behaviour of UNIX paths.  However, by  default  the
2324              file  completion function behaves as if there were a `*' between
2325              the slashes.
2326
2327       stop   If set to `true', the  _history_complete_word  bindable  command
2328              will  stop  once  when reaching the beginning or end of the his‐
2329              tory.  Invoking _history_complete_word will then wrap around  to
2330              the  opposite  end  of  the  history.   If  this style is set to
2331              `false' (the default), _history_complete_word will loop  immedi‐
2332              ately as in a menu completion.
2333
2334       strip-comments
2335              If  set  to `true', this style causes non-essential comment text
2336              to be removed from completion matches.   Currently  it  is  only
2337              used  when completing e-mail addresses where it removes any dis‐
2338              play name  from  the  addresses,  cutting  them  down  to  plain
2339              user@host form.
2340
2341       subst-globs-only
2342              This  is used by the _expand completer.  If it is set to `true',
2343              the expansion will only be used if it  resulted  from  globbing;
2344              hence,  if  expansions  resulted  from the use of the substitute
2345              style described below, but these were  not  further  changed  by
2346              globbing, the expansions will be rejected.
2347
2348              The default for this style is `false'.
2349
2350       substitute
2351              This  boolean  style controls whether the _expand completer will
2352              first try to expand all substitutions in  the  string  (such  as
2353              `$(...)' and `${...}').
2354
2355              The default is `true'.
2356
2357       suffix This  is used by the _expand completer if the word starts with a
2358              tilde or contains a  parameter  expansion.   If  it  is  set  to
2359              `true', the word will only be expanded if it doesn't have a suf‐
2360              fix, i.e. if it is something like `~foo' or `$foo'  rather  than
2361              `~foo/'  or `$foo/bar', unless that suffix itself contains char‐
2362              acters eligible for expansion.  The default for  this  style  is
2363              `true'.
2364
2365       tag-order
2366              This  provides a mechanism for sorting how the tags available in
2367              a particular context will be used.
2368
2369              The values for the style are sets of  space-separated  lists  of
2370              tags.  The tags in each value will be tried at the same time; if
2371              no match is found, the next value is used.  (See  the  file-pat‐
2372              terns style for an exception to this behavior.)
2373
2374              For example:
2375
2376                     zstyle ':completion:*:complete:-command-:*:*' tag-order \
2377                         'commands functions'
2378
2379              specifies  that  completion in command position first offers ex‐
2380              ternal commands and shell functions.   Remaining  tags  will  be
2381              tried if no completions are found.
2382
2383              In  addition to tag names, each string in the value may take one
2384              of the following forms:
2385
2386              -      If any value consists of only a  hyphen,  then  only  the
2387                     tags  specified  in the other values are generated.  Nor‐
2388                     mally all tags not explicitly selected are tried last  if
2389                     the  specified  tags  fail to generate any matches.  This
2390                     means that a single value consisting only of a single hy‐
2391                     phen turns off completion.
2392
2393              ! tags...
2394                     A  string  starting  with  an  exclamation mark specifies
2395                     names of tags that are not to be used.  The effect is the
2396                     same  as  if  all other possible tags for the context had
2397                     been listed.
2398
2399              tag:label ...
2400                     Here, tag is one of the standard tags and label is an ar‐
2401                     bitrary  name.   Matches  are generated as normal but the
2402                     name label is used in contexts instead of tag.   This  is
2403                     not useful in words starting with !.
2404
2405                     If  the  label starts with a hyphen, the tag is prepended
2406                     to the label to form the name used for lookup.  This  can
2407                     be  used  to make the completion system try a certain tag
2408                     more than once, supplying different  style  settings  for
2409                     each attempt; see below for an example.
2410
2411              tag:label:description
2412                     As  before,  but description will replace the `%d' in the
2413                     value of the format style instead of the default descrip‐
2414                     tion  supplied by the completion function.  Spaces in the
2415                     description must be quoted with a backslash.  A `%d'  ap‐
2416                     pearing  in  description is replaced with the description
2417                     given by the completion function.
2418
2419              In any of the forms above the tag may be a  pattern  or  several
2420              patterns  in the form `{pat1,pat2...}'.  In this case all match‐
2421              ing tags will be used except for any  given  explicitly  in  the
2422              same string.
2423
2424              One use of these features is to try one tag more than once, set‐
2425              ting other styles differently on each attempt, but still to  use
2426              all the other tags without having to repeat them all.  For exam‐
2427              ple, to make completion of function names  in  command  position
2428              ignore  all the completion functions starting with an underscore
2429              the first time completion is tried:
2430
2431                     zstyle ':completion:*:*:-command-:*:*' tag-order \
2432                         'functions:-non-comp *' functions
2433                     zstyle ':completion:*:functions-non-comp' \
2434                         ignored-patterns '_*'
2435
2436              On the first attempt, all tags will be offered but the functions
2437              tag  will  be  replaced by functions-non-comp.  The ignored-pat‐
2438              terns style is set for this tag to  exclude  functions  starting
2439              with  an  underscore.  If there are no matches, the second value
2440              of the tag-order style is used which completes  functions  using
2441              the  default  tag,  this  time presumably including all function
2442              names.
2443
2444              The matches for one tag can be split into different groups.  For
2445              example:
2446
2447                     zstyle ':completion:*' tag-order \
2448                         'options:-long:long\ options
2449                          options:-short:short\ options
2450                          options:-single-letter:single\ letter\ options'
2451                     zstyle ':completion:*:options-long' \
2452                          ignored-patterns '[-+](|-|[^-]*)'
2453                     zstyle ':completion:*:options-short' \
2454                          ignored-patterns '--*' '[-+]?'
2455                     zstyle ':completion:*:options-single-letter' \
2456                          ignored-patterns '???*'
2457
2458              With the group-names style set, options beginning with `--', op‐
2459              tions beginning with a single `-' or `+' but containing multiple
2460              characters, and single-letter options will be displayed in sepa‐
2461              rate groups with different descriptions.
2462
2463              Another use of patterns is to try multiple match  specifications
2464              one after another.  The matcher-list style offers something sim‐
2465              ilar, but it is tested very early in the completion  system  and
2466              hence  can't  be  set  for single commands nor for more specific
2467              contexts.  Here is how to  try  normal  completion  without  any
2468              match specification and, if that generates no matches, try again
2469              with case-insensitive matching, restricting the effect to  argu‐
2470              ments of the command foo:
2471
2472                     zstyle ':completion:*:*:foo:*:*' tag-order '*' '*:-case'
2473                     zstyle ':completion:*-case' matcher 'm:{a-z}={A-Z}'
2474
2475              First,  all the tags offered when completing after foo are tried
2476              using the normal tag name.  If that generates  no  matches,  the
2477              second  value  of  tag-order is used, which tries all tags again
2478              except that this time each has -case appended to  its  name  for
2479              lookup  of  styles.   Hence  this time the value for the matcher
2480              style from the second call to zstyle in the example is  used  to
2481              make completion case-insensitive.
2482
2483              It  is  possible to use the -e option of the zstyle builtin com‐
2484              mand to specify conditions for the use of particular tags.   For
2485              example:
2486
2487                     zstyle -e '*:-command-:*' tag-order '
2488                         if [[ -n $PREFIX$SUFFIX ]]; then
2489                           reply=( )
2490                         else
2491                           reply=( - )
2492                         fi'
2493
2494              Completion  in  command  position  will be attempted only if the
2495              string typed so far is not empty.  This is tested using the PRE‐
2496              FIX  special  parameter; see zshcompwid for a description of pa‐
2497              rameters which are special inside completion  widgets.   Setting
2498              reply to an empty array provides the default behaviour of trying
2499              all tags at once; setting it to an array containing only  a  hy‐
2500              phen disables the use of all tags and hence of all completions.
2501
2502              If  no  tag-order  style  has  been  defined  for a context, the
2503              strings `(|*-)argument-*  (|*-)option-*  values'  and  `options'
2504              plus all tags offered by the completion function will be used to
2505              provide  a  sensible  default  behavior  that  causes  arguments
2506              (whether normal command arguments or arguments of options) to be
2507              completed before option names for most commands.
2508
2509       urls   This is used together with the urls tag by functions  completing
2510              URLs.
2511
2512              If  the  value  consists of more than one string, or if the only
2513              string does not name a file or directory, the strings  are  used
2514              as the URLs to complete.
2515
2516              If  the  value  contains  only one string which is the name of a
2517              normal file the URLs are taken from that file  (where  the  URLs
2518              may be separated by white space or newlines).
2519
2520              Finally,  if the only string in the value names a directory, the
2521              directory hierarchy rooted at this directory gives  the  comple‐
2522              tions.   The  top  level  directory  should  be  the file access
2523              method, such as `http', `ftp', `bookmark' and so  on.   In  many
2524              cases the next level of directories will be a filename.  The di‐
2525              rectory hierarchy can descend as deep as necessary.
2526
2527              For example,
2528
2529                     zstyle ':completion:*' urls ~/.urls
2530                     mkdir -p ~/.urls/ftp/ftp.zsh.org/pub
2531
2532              allows  completion  of   all   the   components   of   the   URL
2533              ftp://ftp.zsh.org/pub after suitable commands such as `netscape'
2534              or `lynx'.  Note, however, that access  methods  and  files  are
2535              completed  separately, so if the hosts style is set hosts can be
2536              completed without reference to the urls style.
2537
2538              See the description in the function _urls itself for more infor‐
2539              mation (e.g. `more $^fpath/_urls(N)').
2540
2541       use-cache
2542              If  this  is  set, the completion caching layer is activated for
2543              any  completions  which  use  it  (via  the  _store_cache,  _re‐
2544              trieve_cache, and _cache_invalid functions).  The directory con‐
2545              taining the cache files  can  be  changed  with  the  cache-path
2546              style.
2547
2548       use-compctl
2549              If  this style is set to a string not equal to false, 0, no, and
2550              off, the completion system may use any completion specifications
2551              defined  with  the compctl builtin command.  If the style is un‐
2552              set, this is done only if the zsh/compctl module is loaded.  The
2553              string may also contain the substring `first' to use completions
2554              defined with `compctl -T', and the substring  `default'  to  use
2555              the completion defined with `compctl -D'.
2556
2557              Note  that  this  is only intended to smooth the transition from
2558              compctl to the new completion system and may  disappear  in  the
2559              future.
2560
2561              Note also that the definitions from compctl will only be used if
2562              there is no specific completion  function  for  the  command  in
2563              question.   For example, if there is a function _foo to complete
2564              arguments to the command foo, compctl will never be invoked  for
2565              foo.   However,  the  compctl  version will be tried if foo only
2566              uses default completion.
2567
2568       use-ip By default, the function _hosts that completes host names strips
2569              IP  addresses  from entries read from host databases such as NIS
2570              and ssh files.  If this style is `true',  the  corresponding  IP
2571              addresses  can  be  completed as well.  This style is not use in
2572              any context where the hosts style is set; note also it  must  be
2573              set  before  the cache of host names is generated (typically the
2574              first completion attempt).
2575
2576       users  This may be set to a list of usernames to be completed.   If  it
2577              is  not set all usernames will be completed.  Note that if it is
2578              set only that list of users will be completed; this  is  because
2579              on some systems querying all users can take a prohibitive amount
2580              of time.
2581
2582       users-hosts
2583              The values of this style should be of the  form  `user@host'  or
2584              `user:host'.  It  is  used for commands that need pairs of user-
2585              and hostnames.  These commands will complete usernames from this
2586              style  (only),  and will restrict subsequent hostname completion
2587              to hosts paired with that user in  one  of  the  values  of  the
2588              style.
2589
2590              It  is possible to group values for sets of commands which allow
2591              a remote login, such as rlogin and ssh, by using the my-accounts
2592              tag.  Similarly, values for sets of commands which usually refer
2593              to the accounts of other people, such as talk and finger, can be
2594              grouped  by  using the other-accounts tag.  More ambivalent com‐
2595              mands may use the accounts tag.
2596
2597       users-hosts-ports
2598              Like users-hosts but used for commands like telnet and  contain‐
2599              ing strings of the form `user@host:port'.
2600
2601       verbose
2602              If set, as it is by default, the completion listing is more ver‐
2603              bose.  In particular many commands show descriptions for options
2604              if this style is `true'.
2605
2606       word   This  is  used by the _list completer, which prevents the inser‐
2607              tion of completions until a second completion attempt  when  the
2608              line has not changed.  The normal way of finding out if the line
2609              has changed is to compare its entire contents  between  the  two
2610              occasions.   If  this style is `true', the comparison is instead
2611              performed only on the current word.  Hence if completion is per‐
2612              formed  on  another word with the same contents, completion will
2613              not be delayed.
2614

CONTROL FUNCTIONS

2616       The initialization script compinit redefines all the widgets which per‐
2617       form  completion  to  call the supplied widget function _main_complete.
2618       This function acts as a wrapper calling the so-called `completer' func‐
2619       tions  that  generate  matches.  If _main_complete is called with argu‐
2620       ments, these are taken as the names of completer functions to be called
2621       in the order given.  If no arguments are given, the set of functions to
2622       try is taken from the completer style.  For example, to use normal com‐
2623       pletion and correction if that doesn't generate any matches:
2624
2625              zstyle ':completion:*' completer _complete _correct
2626
2627       after  calling compinit. The default value for this style is `_complete
2628       _ignored', i.e. normally only ordinary completion is tried, first  with
2629       the  effect  of  the  ignored-patterns  style and then without it.  The
2630       _main_complete function uses the return status of the  completer  func‐
2631       tions  to  decide  if other completers should be called.  If the return
2632       status is zero, no other completers are tried  and  the  _main_complete
2633       function returns.
2634
2635       If  the  first argument to _main_complete is a single hyphen, the argu‐
2636       ments will not be taken as names of completers.   Instead,  the  second
2637       argument  gives a name to use in the completer field of the context and
2638       the other arguments give a command name and arguments to call to gener‐
2639       ate the matches.
2640
2641       The  following  completer  functions are contained in the distribution,
2642       although users may write their own.  Note that in contexts the  leading
2643       underscore  is  stripped,  for example basic completion is performed in
2644       the context `:completion::complete:...'.
2645
2646       _all_matches
2647              This completer can be used to add a  string  consisting  of  all
2648              other matches.  As it influences later completers it must appear
2649              as the first completer in the list.  The list of all matches  is
2650              affected by the avoid-completer and old-matches styles described
2651              above.
2652
2653              It may be useful to use the _generic function described below to
2654              bind _all_matches to its own keystroke, for example:
2655
2656                     zle -C all-matches complete-word _generic
2657                     bindkey '^Xa' all-matches
2658                     zstyle ':completion:all-matches:*' old-matches only
2659                     zstyle ':completion:all-matches::::' completer _all_matches
2660
2661              Note  that  this does not generate completions by itself:  first
2662              use any of the standard ways of generating  a  list  of  comple‐
2663              tions, then use ^Xa to show all matches.  It is possible instead
2664              to add a standard completer to the list  and  request  that  the
2665              list of all matches should be directly inserted:
2666
2667                     zstyle ':completion:all-matches::::' completer \
2668                            _all_matches _complete
2669                     zstyle ':completion:all-matches:*' insert true
2670
2671              In this case the old-matches style should not be set.
2672
2673       _approximate
2674              This  is similar to the basic _complete completer but allows the
2675              completions to undergo corrections.  The maximum number  of  er‐
2676              rors  can be specified by the max-errors style; see the descrip‐
2677              tion of approximate matching in zshexpn(1) for  how  errors  are
2678              counted.   Normally  this completer will only be tried after the
2679              normal _complete completer:
2680
2681                     zstyle ':completion:*' completer _complete _approximate
2682
2683              This will give correcting completion if and only if normal  com‐
2684              pletion  yields no possible completions.  When corrected comple‐
2685              tions are found, the completer will normally start menu  comple‐
2686              tion allowing you to cycle through these strings.
2687
2688              This  completer uses the tags corrections and original when gen‐
2689              erating the possible corrections and the original  string.   The
2690              format style for the former may contain the additional sequences
2691              `%e' and `%o' which will be replaced by the number of errors ac‐
2692              cepted  to generate the corrections and the original string, re‐
2693              spectively.
2694
2695              The completer progressively increases the number of  errors  al‐
2696              lowed  up  to the limit by the max-errors style, hence if a com‐
2697              pletion is found with one error, no completions with two  errors
2698              will be shown, and so on.  It modifies the completer name in the
2699              context to indicate the number of errors  being  tried:  on  the
2700              first  try  the completer field contains `approximate-1', on the
2701              second try `approximate-2', and so on.
2702
2703              When _approximate is called from another function, the number of
2704              errors to accept may be passed with the -a option.  The argument
2705              is in the same format  as  the  max-errors  style,  all  in  one
2706              string.
2707
2708              Note  that  this completer (and the _correct completer mentioned
2709              below) can be quite expensive to call, especially when  a  large
2710              number  of  errors are allowed.  One way to avoid this is to set
2711              up the completer style using the -e option  to  zstyle  so  that
2712              some  completers  are  only  used when completion is attempted a
2713              second time on the same string, e.g.:
2714
2715                     zstyle -e ':completion:*' completer '
2716                       if [[ $_last_try != "$HISTNO$BUFFER$CURSOR" ]]; then
2717                         _last_try="$HISTNO$BUFFER$CURSOR"
2718                         reply=(_complete _match _prefix)
2719                       else
2720                         reply=(_ignored _correct _approximate)
2721                       fi'
2722
2723              This uses the HISTNO parameter and the BUFFER and CURSOR special
2724              parameters  that are available inside zle and completion widgets
2725              to find out if the command line hasn't changed  since  the  last
2726              time completion was tried.  Only then are the _ignored, _correct
2727              and _approximate completers called.
2728
2729       _canonical_paths [ -A var ] [ -N ] [ -MJV12nfX ] tag descr [ paths  ...
2730       ]
2731              This  completion  function  completes all paths given to it, and
2732              also tries to offer completions which point to the same file  as
2733              one  of  the paths given (relative path when an absolute path is
2734              given, and vice versa; when ..'s are present in the word  to  be
2735              completed; and some paths got from symlinks).
2736
2737              -A, if specified, takes the paths from the array variable speci‐
2738              fied. Paths can also be specified on the command line  as  shown
2739              above.   -N,  if  specified,  prevents  canonicalizing the paths
2740              given before using them for completion, in case they are already
2741              so.  The  options  -M,  -J, -V, -1, -2, -n, -F, -X are passed to
2742              compadd.
2743
2744              See _description for a description of tag and descr.
2745
2746       _cmdambivalent
2747              Completes the remaining positional arguments as an external com‐
2748              mand.   The  external command and its arguments are completed as
2749              separate arguments  (in  a  manner  appropriate  for  completing
2750              /usr/bin/env)  if there are two or more remaining positional ar‐
2751              guments on the command line, and as a quoted command string  (in
2752              the  manner  of system(...)) otherwise.  See also _cmdstring and
2753              _precommand.
2754
2755              This function takes no arguments.
2756
2757       _cmdstring
2758              Completes an external command as a single argument, as for  sys‐
2759              tem(...).
2760
2761       _complete
2762              This  completer  generates  all  possible  completions in a con‐
2763              text-sensitive manner, i.e. using the settings defined with  the
2764              compdef function explained above and the current settings of all
2765              special parameters.  This gives the normal completion behaviour.
2766
2767              To complete arguments of commands, _complete  uses  the  utility
2768              function  _normal,  which is in turn responsible for finding the
2769              particular function; it is described below.  Various contexts of
2770              the  form -context- are handled specifically. These are all men‐
2771              tioned above as possible arguments to the #compdef tag.
2772
2773              Before trying to find a function for a specific  context,  _com‐
2774              plete  checks  if  the  parameter  `compcontext' is set. Setting
2775              `compcontext' allows the  usual  completion  dispatching  to  be
2776              overridden  which  is  useful  in places such as a function that
2777              uses vared for input. If it is set to an array, the elements are
2778              taken  to  be the possible matches which will be completed using
2779              the tag `values' and the description `value'. If it is set to an
2780              associative array, the keys are used as the possible completions
2781              and the values (if non-empty) are used as descriptions  for  the
2782              matches.  If `compcontext' is set to a string containing colons,
2783              it should be of the form `tag:descr:action'.  In this  case  the
2784              tag and descr give the tag and description to use and the action
2785              indicates what should be completed in one of the forms  accepted
2786              by the _arguments utility function described below.
2787
2788              Finally, if `compcontext' is set to a string without colons, the
2789              value is taken as the name of the context to use and  the  func‐
2790              tion defined for that context will be called.  For this purpose,
2791              there is a special context named -command-line-  that  completes
2792              whole command lines (commands and their arguments).  This is not
2793              used by the completion system itself but is nonetheless  handled
2794              when explicitly called.
2795
2796       _correct
2797              Generate corrections, but not completions, for the current word;
2798              this is similar to _approximate but will not allow any number of
2799              extra  characters at the cursor as that completer does.  The ef‐
2800              fect is similar to spell-checking.  It is based on _approximate,
2801              but the completer field in the context name is correct.
2802
2803              For example, with:
2804
2805                     zstyle ':completion:::::' completer \
2806                            _complete _correct _approximate
2807                     zstyle ':completion:*:correct:::' max-errors 2 not-numeric
2808                     zstyle ':completion:*:approximate:::' max-errors 3 numeric
2809
2810              correction  will accept up to two errors.  If a numeric argument
2811              is given, correction will not be performed, but correcting  com‐
2812              pletion  will be, and will accept as many errors as given by the
2813              numeric argument.  Without a numeric argument, first  correction
2814              and then correcting completion will be tried, with the first one
2815              accepting two errors and the second one accepting three errors.
2816
2817              When _correct is called as a function, the number of  errors  to
2818              accept may be given following the -a option.  The argument is in
2819              the same form a values to the accept style, all in one string.
2820
2821              This completer function is intended to be used without the  _ap‐
2822              proximate  completer or, as in the example, just before it.  Us‐
2823              ing it after the _approximate completer is  useless  since  _ap‐
2824              proximate will at least generate the corrected strings generated
2825              by the _correct completer -- and probably more.
2826
2827       _expand
2828              This completer function does not really perform completion,  but
2829              instead  checks  if the word on the command line is eligible for
2830              expansion and, if it is, gives detailed control  over  how  this
2831              expansion  is  done.   For this to happen, the completion system
2832              needs to be invoked with complete-word,  not  expand-or-complete
2833              (the  default  binding for TAB), as otherwise the string will be
2834              expanded by the shell's internal mechanism before the completion
2835              system  is  started.   Note also this completer should be called
2836              before the _complete completer function.
2837
2838              The tags used when generating expansions are all-expansions  for
2839              the  string  containing all possible expansions, expansions when
2840              adding the possible expansions as single  matches  and  original
2841              when  adding  the  original  string from the line.  The order in
2842              which these strings are generated, if at all, can be  controlled
2843              by the group-order and tag-order styles, as usual.
2844
2845              The format string for all-expansions and for expansions may con‐
2846              tain the sequence `%o' which will be replaced  by  the  original
2847              string from the line.
2848
2849              The  kind  of expansion to be tried is controlled by the substi‐
2850              tute, glob and subst-globs-only styles.
2851
2852              It is also possible to call _expand as a function, in which case
2853              the different modes may be selected with options: -s for substi‐
2854              tute, -g for glob and -o for subst-globs-only.
2855
2856       _expand_alias
2857              If the word the cursor is on is an alias, it is expanded and  no
2858              other  completers are called.  The types of aliases which are to
2859              be expanded can be controlled with the  styles  regular,  global
2860              and disabled.
2861
2862              This function is also a bindable command, see the section `Bind‐
2863              able Commands' below.
2864
2865       _extensions
2866              If the cursor follows the string `*.', filename  extensions  are
2867              completed. The extensions are taken from files in current direc‐
2868              tory or a directory specified at the beginning  of  the  current
2869              word.  For  exact  matches,  completion continues to allow other
2870              completers such as _expand to expand the pattern.  The  standard
2871              add-space and prefix-hidden styles are observed.
2872
2873       _external_pwds
2874              Completes  current  directories of other zsh processes belonging
2875              to the current user.
2876
2877              This is intended to be used via _generic, bound to a custom  key
2878              combination.  Note  that pattern matching is enabled so matching
2879              is performed similar to how it works with the _match completer.
2880
2881       _history
2882              Complete words from the shell's  command   history.   This  com‐
2883              pleter can be controlled by the remove-all-dups, and sort styles
2884              as for the _history_complete_word bindable command, see the sec‐
2885              tion  `Bindable Commands' below and the section `Completion Sys‐
2886              tem Configuration' above.
2887
2888       _ignored
2889              The ignored-patterns style can be set  to  a  list  of  patterns
2890              which  are  compared against possible completions; matching ones
2891              are removed.  With this completer those  matches  can  be  rein‐
2892              stated, as if no ignored-patterns style were set.  The completer
2893              actually generates its own list of matches; which completers are
2894              invoked  is  determined  in the same way as for the _prefix com‐
2895              pleter.  The single-ignored style is also available as described
2896              above.
2897
2898       _list  This completer allows the insertion of matches to be delayed un‐
2899              til completion is attempted a second time without  the  word  on
2900              the  line being changed.  On the first attempt, only the list of
2901              matches will be shown.  It is affected by the  styles  condition
2902              and  word,  see  the  section  `Completion System Configuration'
2903              above.
2904
2905       _match This completer is intended to be used after the  _complete  com‐
2906              pleter.  It behaves similarly but the string on the command line
2907              may be a pattern to match against trial completions.  This gives
2908              the effect of the GLOB_COMPLETE option.
2909
2910              Normally completion will be performed by taking the pattern from
2911              the line, inserting a `*' at the cursor position  and  comparing
2912              the  resulting  pattern with the possible completions generated.
2913              This can be modified with  the  match-original  style  described
2914              above.
2915
2916              The  generated  matches will be offered in a menu completion un‐
2917              less the insert-unambiguous style is set to `true'; see the  de‐
2918              scription above for other options for this style.
2919
2920              Note that matcher specifications defined globally or used by the
2921              completion functions (the styles matcher-list and matcher)  will
2922              not be used.
2923
2924       _menu  This  completer  was  written as simple example function to show
2925              how menu completion can be enabled in shell  code.  However,  it
2926              has  the notable effect of disabling menu selection which can be
2927              useful with _generic based widgets. It should  be  used  as  the
2928              first  completer  in the list.  Note that this is independent of
2929              the setting of the MENU_COMPLETE option and does not  work  with
2930              the other menu completion widgets such as reverse-menu-complete,
2931              or accept-and-menu-complete.
2932
2933       _oldlist
2934              This completer controls how the standard completion widgets  be‐
2935              have  when  there  is  an existing list of completions which may
2936              have been generated  by  a  special  completion  (i.e.  a  sepa‐
2937              rately-bound  completion  command).  It allows the ordinary com‐
2938              pletion keys to continue to use the  list  of  completions  thus
2939              generated,  instead  of producing a new list of ordinary contex‐
2940              tual completions.  It should appear in the  list  of  completers
2941              before  any  of the widgets which generate matches.  It uses two
2942              styles: old-list and old-menu, see the section `Completion  Sys‐
2943              tem Configuration' above.
2944
2945       _precommand
2946              Complete an external command in word-separated arguments, as for
2947              exec and /usr/bin/env.
2948
2949       _prefix
2950              This completer can be used to try  completion  with  the  suffix
2951              (everything after the cursor) ignored.  In other words, the suf‐
2952              fix will not be considered to be part of the word  to  complete.
2953              The effect is similar to the expand-or-complete-prefix command.
2954
2955              The completer style is used to decide which other completers are
2956              to be called to generate matches.  If this style is  unset,  the
2957              list  of  completers  set for the current context is used -- ex‐
2958              cept, of course, the _prefix completer itself.  Furthermore,  if
2959              this  completer appears more than once in the list of completers
2960              only those completers not already tried by the  last  invocation
2961              of _prefix will be called.
2962
2963              For example, consider this global completer style:
2964
2965                     zstyle ':completion:*' completer \
2966                         _complete _prefix _correct _prefix:foo
2967
2968              Here, the _prefix completer tries normal completion but ignoring
2969              the suffix.  If that doesn't generate any matches,  and  neither
2970              does  the  call to the _correct completer after it, _prefix will
2971              be called a second time and, now only trying correction with the
2972              suffix  ignored.  On the second invocation the completer part of
2973              the context appears as `foo'.
2974
2975              To use _prefix as the last resort and try only normal completion
2976              when it is invoked:
2977
2978                     zstyle ':completion:*' completer _complete ... _prefix
2979                     zstyle ':completion::prefix:*' completer _complete
2980
2981              The  add-space  style is also respected.  If it is set to `true'
2982              then _prefix will insert a space between the  matches  generated
2983              (if any) and the suffix.
2984
2985              Note  that this completer is only useful if the COMPLETE_IN_WORD
2986              option is set; otherwise, the cursor will be moved to the end of
2987              the  current word before the completion code is called and hence
2988              there will be no suffix.
2989
2990       _user_expand
2991              This completer behaves similarly to the  _expand  completer  but
2992              instead  performs  expansions  defined  by  users.   The  styles
2993              add-space and sort styles specific to the _expand completer  are
2994              usable  with  _user_expand  in  addition to other styles handled
2995              more generally by the completion system.  The tag all-expansions
2996              is also available.
2997
2998              The  expansion  depends on the array style user-expand being de‐
2999              fined for the current context; remember  that  the  context  for
3000              completers  is less specific than that for contextual completion
3001              as the full context has not yet been  determined.   Elements  of
3002              the array may have one of the following forms:
3003
3004              $hash
3005
3006                     hash  is  the name of an associative array.  Note this is
3007                     not a full parameter expression,  merely  a  $,  suitably
3008                     quoted  to  prevent  immediate expansion, followed by the
3009                     name of an associative array.   If  the  trial  expansion
3010                     word  matches  a  key in hash, the resulting expansion is
3011                     the corresponding value.
3012              _func
3013
3014                     _func is the name of a shell function whose name must be‐
3015                     gin with _ but is not otherwise special to the completion
3016                     system.  The function is called with the trial word as an
3017                     argument.   If  the  word is to be expanded, the function
3018                     should set the array reply to a list of expansions.   Op‐
3019                     tionally, it can set REPLY to a word that will be used as
3020                     a description for the set of expansions.  The return sta‐
3021                     tus of the function is irrelevant.

BINDABLE COMMANDS

3023       In  addition  to  the context-dependent completions provided, which are
3024       expected to work in an intuitively obvious way, there are a few widgets
3025       implementing  special  behaviour which can be bound separately to keys.
3026       The following is a list of these and their default bindings.
3027
3028       _bash_completions
3029              This function is used by two  widgets,  _bash_complete-word  and
3030              _bash_list-choices.   It  exists  to  provide compatibility with
3031              completion bindings in bash.  The last character of the  binding
3032              determines  what is completed: `!', command names; `$', environ‐
3033              ment variables; `@', host  names;  `/',  file  names;  `~'  user
3034              names.   In bash, the binding preceded by `\e' gives completion,
3035              and preceded by `^X' lists options.  As some of  these  bindings
3036              clash with standard zsh bindings, only `\e~' and `^X~' are bound
3037              by default.  To add the rest, the following should be  added  to
3038              .zshrc after compinit has been run:
3039
3040                     for key in '!' '$' '@' '/' '~'; do
3041                       bindkey "\e$key" _bash_complete-word
3042                       bindkey "^X$key" _bash_list-choices
3043                     done
3044
3045              This  includes  the  bindings  for `~' in case they were already
3046              bound to something else; the completion code does  not  override
3047              user bindings.
3048
3049       _correct_filename (^XC)
3050              Correct  the filename path at the cursor position.  Allows up to
3051              six errors in the name.  Can also be called with an argument  to
3052              correct a filename path, independently of zle; the correction is
3053              printed on standard output.
3054
3055       _correct_word (^Xc)
3056              Performs correction of the current argument using the usual con‐
3057              textual  completions as possible choices. This stores the string
3058              `correct-word' in the function field of  the  context  name  and
3059              then calls the _correct completer.
3060
3061       _expand_alias (^Xa)
3062              This  function can be used as a completer and as a bindable com‐
3063              mand.  It expands the word the cursor is on if it is  an  alias.
3064              The  types  of  alias expanded can be controlled with the styles
3065              regular, global and disabled.
3066
3067              When used as a bindable command there is one additional  feature
3068              that  can  be  selected by setting the complete style to `true'.
3069              In this case, if the word is not the  name  of  an  alias,  _ex‐
3070              pand_alias tries to complete the word to a full alias name with‐
3071              out expanding it.  It leaves the cursor directly after the  com‐
3072              pleted word so that invoking _expand_alias once more will expand
3073              the now-complete alias name.
3074
3075       _expand_word (^Xe)
3076              Performs expansion on the current word:  equivalent to the stan‐
3077              dard  expand-word command, but using the _expand completer.  Be‐
3078              fore calling it, the function field of the  context  is  set  to
3079              `expand-word'.
3080
3081       _generic
3082              This  function  is  not defined as a widget and not bound by de‐
3083              fault.  However, it can be used to define a widget and will then
3084              store  the  name of the widget in the function field of the con‐
3085              text and call the completion system.  This allows custom comple‐
3086              tion  widgets with their own set of style settings to be defined
3087              easily.  For example, to define a widget  that  performs  normal
3088              completion and starts menu selection:
3089
3090                     zle -C foo complete-word _generic
3091                     bindkey '...' foo
3092                     zstyle ':completion:foo:*' menu yes select=1
3093
3094              Note  in  particular that the completer style may be set for the
3095              context in order to change the set of functions used to generate
3096              possible  matches.   If _generic is called with arguments, those
3097              are passed through to _main_complete as the list  of  completers
3098              in place of those defined by the completer style.
3099
3100       _history_complete_word (\e/)
3101              Complete  words  from the shell's command history. This uses the
3102              list, remove-all-dups, sort, and stop styles.
3103
3104       _most_recent_file (^Xm)
3105              Complete the name of the most recently  modified  file  matching
3106              the  pattern on the command line (which may be blank).  If given
3107              a numeric argument N, complete the Nth  most  recently  modified
3108              file.  Note the completion, if any, is always unique.
3109
3110       _next_tags (^Xn)
3111              This command alters the set of matches used to that for the next
3112              tag, or set of tags, either as given by the tag-order  style  or
3113              as  set  by default; these matches would otherwise not be avail‐
3114              able.  Successive invocations of the command cycle  through  all
3115              possible sets of tags.
3116
3117       _read_comp (^X^R)
3118              Prompt the user for a string, and use that to perform completion
3119              on the current  word.   There  are  two  possibilities  for  the
3120              string.   First, it can be a set of words beginning `_', for ex‐
3121              ample `_files -/', in which case the function with any arguments
3122              will  be  called to generate the completions.  Unambiguous parts
3123              of the function name will  be  completed  automatically  (normal
3124              completion  is  not  available  at  this point) until a space is
3125              typed.
3126
3127              Second, any other string will be passed as a set of arguments to
3128              compadd and should hence be an expression specifying what should
3129              be completed.
3130
3131              A very restricted set of  editing  commands  is  available  when
3132              reading  the  string:  `DEL' and `^H' delete the last character;
3133              `^U' deletes the line, and `^C' and  `^G'  abort  the  function,
3134              while  `RET'  accepts  the  completion.  Note the string is used
3135              verbatim as a command line, so arguments must be quoted  in  ac‐
3136              cordance with standard shell rules.
3137
3138              Once  a  string  has been read, the next call to _read_comp will
3139              use the existing string instead of reading a new one.  To  force
3140              a  new  string  to be read, call _read_comp with a numeric argu‐
3141              ment.
3142
3143       _complete_debug (^X?)
3144              This widget performs ordinary completion, but captures in a tem‐
3145              porary  file  a trace of the shell commands executed by the com‐
3146              pletion system.  Each completion attempt gets its own  file.   A
3147              command  to  view  each of these files is pushed onto the editor
3148              buffer stack.
3149
3150       _complete_help (^Xh)
3151              This widget displays information about the  context  names,  the
3152              tags,  and  the completion functions used when completing at the
3153              current cursor position. If given a numeric argument other  than
3154              1 (as in `ESC-2 ^Xh'), then the styles used and the contexts for
3155              which they are used will be shown, too.
3156
3157              Note that the information about styles may be incomplete; it de‐
3158              pends on the information available from the completion functions
3159              called, which in turn is determined by the user's own styles and
3160              other settings.
3161
3162       _complete_help_generic
3163              Unlike  other  commands  listed  here, this must be created as a
3164              normal ZLE widget rather than a completion widget (i.e. with zle
3165              -N).   It is used for generating help with a widget bound to the
3166              _generic widget that is described above.
3167
3168              If this widget is created using the name of the function, as  it
3169              is  by  default, then when executed it will read a key sequence.
3170              This is expected to be bound to a call to a completion  function
3171              that  uses  the  _generic widget.  That widget will be executed,
3172              and information provided in  the  same  format  that  the  _com‐
3173              plete_help widget displays for contextual completion.
3174
3175              If  the  widget's name contains debug, for example if it is cre‐
3176              ated as `zle -N _complete_debug_generic _complete_help_generic',
3177              it  will  read and execute the keystring for a generic widget as
3178              before, but then generate debugging information as done by _com‐
3179              plete_debug for contextual completion.
3180
3181              If  the  widget's  name  contains  noread,  it  will  not read a
3182              keystring but instead arrange that the next  use  of  a  generic
3183              widget  run  in the same shell will have the effect as described
3184              above.
3185
3186              The   widget   works   by   setting    the    shell    parameter
3187              ZSH_TRACE_GENERIC_WIDGET  which  is read by _generic.  Unsetting
3188              the parameter cancels any pending effect of the noread form.
3189
3190              For example, after executing the following:
3191
3192                     zle -N _complete_debug_generic _complete_help_generic
3193                     bindkey '^x:' _complete_debug_generic
3194
3195              typing `C-x :' followed by the key sequence for a generic widget
3196              will cause trace output for that widget to be saved to a file.
3197
3198       _complete_tag (^Xt)
3199              This  widget completes symbol tags created by the etags or ctags
3200              programmes (note there is no connection with the completion sys‐
3201              tem's  tags) stored in a file TAGS, in the format used by etags,
3202              or tags, in the format created by ctags.  It will look  back  up
3203              the  path  hierarchy for the first occurrence of either file; if
3204              both exist, the file TAGS is preferred.   You  can  specify  the
3205              full path to a TAGS or tags file by setting the parameter $TAGS‐
3206              FILE or $tagsfile respectively.   The  corresponding  completion
3207              tags used are etags and vtags, after emacs and vi respectively.
3208

UTILITY FUNCTIONS

3210       Descriptions follow for utility functions that may be useful when writ‐
3211       ing completion functions.  If functions are  installed  in  subdirecto‐
3212       ries,  most of these reside in the Base subdirectory.  Like the example
3213       functions for commands in the distribution, the utility functions  gen‐
3214       erating  matches  all follow the convention of returning status zero if
3215       they generated completions and  non-zero  if  no  matching  completions
3216       could be added.
3217
3218       _absolute_command_paths
3219              This function completes external commands as absolute paths (un‐
3220              like _command_names -e which  completes  their  basenames).   It
3221              takes no arguments.
3222
3223       _all_labels [ -x ] [ -12VJ ] tag name descr [ command arg ... ]
3224              This  is  a convenient interface to the _next_label function be‐
3225              low, implementing the loop shown  in  the  _next_label  example.
3226              The  command  and  its  arguments  are  called  to  generate the
3227              matches.  The options stored in the parameter name will automat‐
3228              ically  be  inserted  into the args passed to the command.  Nor‐
3229              mally, they are put directly after the command, but  if  one  of
3230              the  args  is a single hyphen, they are inserted directly before
3231              that.  If the hyphen is the last argument, it  will  be  removed
3232              from  the  argument list before the command is called.  This al‐
3233              lows _all_labels to be  used  in  almost  all  cases  where  the
3234              matches can be generated by a single call to the compadd builtin
3235              command or by a call to one of the utility functions.
3236
3237              For example:
3238
3239                     local expl
3240                     ...
3241                     if _requested foo; then
3242                       ...
3243                       _all_labels foo expl '...' compadd ... - $matches
3244                     fi
3245
3246              Will complete the strings from the matches parameter, using com‐
3247              padd  with  additional  options  which will take precedence over
3248              those generated by _all_labels.
3249
3250       _alternative [ -O name ] [ -C name ] spec ...
3251              This function is useful in simple cases where multiple tags  are
3252              available.   Essentially  it  implements a loop like the one de‐
3253              scribed for the _tags function below.
3254
3255              The tags to use and the action to perform if a tag is  requested
3256              are  described  using  the specs which are of the form: `tag:de‐
3257              scr:action'.  The tags are offered using _tags and if the tag is
3258              requested, the action is executed with the given description de‐
3259              scr.  The actions are those accepted by the _arguments  function
3260              (described below), with the following exceptions:
3261              •      The `->state' and `=...' forms are not supported.
3262
3263
3264              •      The  `((a\:bar  b\:baz))' form does not need the colon to
3265                     be escaped,  since  the  specs  have  no  colon-separated
3266                     fields after the action.
3267
3268
3269              For example, the action may be a simple function call:
3270
3271                     _alternative \
3272                         'users:user:_users' \
3273                         'hosts:host:_hosts'
3274
3275              offers usernames and hostnames as possible matches, generated by
3276              the _users and _hosts functions respectively.
3277
3278              Like _arguments, this function uses _all_labels to  execute  the
3279              actions,  which  will  loop over all sets of tags.  Special han‐
3280              dling is only required if there is an additional valid tag,  for
3281              example inside a function called from _alternative.
3282
3283              The  option  `-O  name' is used in the same way as by the _argu‐
3284              ments function.  In other words, the elements of the name  array
3285              will be passed to compadd when executing an action.
3286
3287              Like  _tags  this function supports the -C option to give a dif‐
3288              ferent name for the argument context field.
3289
3290
3291       _arguments [ -nswWCRS ] [ -A pat ] [ -O name ] [ -M matchspec ]
3292                  [ : ] spec ...
3293       _arguments [ opt ... ] -- [ -l ] [ -i pats ] [ -s pair ]
3294                  [ helpspec ...]
3295              This function can be used to give a complete  specification  for
3296              completion  for  a  command whose arguments follow standard UNIX
3297              option and argument conventions.
3298
3299              Options Overview
3300
3301              Options to _arguments itself must be in separate words, i.e.  -s
3302              -w,  not  -sw.   The options are followed by specs that describe
3303              options and arguments of the analyzed command.  To avoid ambigu‐
3304              ity,  all options to _arguments itself may be separated from the
3305              spec forms by a single colon.
3306
3307              The `--' form is used to intuit spec forms from the help  output
3308              of the command being analyzed, and is described in detail below.
3309              The opts for the `--' form are otherwise the same options as the
3310              first  form.  Note that `-s' following `--' has a distinct mean‐
3311              ing from `-s' preceding `--', and both may appear.
3312
3313              The option switches -s, -S, -A, -w, and -W affect how _arguments
3314              parses  the analyzed command line's options.  These switches are
3315              useful for commands with standard argument parsing.
3316
3317              The options of _arguments have the following meanings:
3318
3319              -n     With this option, _arguments sets the  parameter  NORMARG
3320                     to  the  position  of  the  first  normal argument in the
3321                     $words array, i.e. the position after the end of the  op‐
3322                     tions.  If that argument has not been reached, NORMARG is
3323                     set to -1.  The caller should declare  `integer  NORMARG'
3324                     if  the  -n  option is passed; otherwise the parameter is
3325                     not used.
3326
3327              -s     Enable option stacking for single-letter options, whereby
3328                     multiple  single-letter  options  may  be combined into a
3329                     single word.  For example, the two options `-x' and  `-y'
3330                     may  be  combined  into a single word `-xy'.  By default,
3331                     every word corresponds to a single option name (`-xy'  is
3332                     a single option named `xy').
3333
3334                     Options  beginning  with a single hyphen or plus sign are
3335                     eligible for stacking; words beginning with  two  hyphens
3336                     are not.
3337
3338                     Note  that  -s after -- has a different meaning, which is
3339                     documented in the segment entitled `Deriving  spec  forms
3340                     from the help output'.
3341
3342              -w     In combination with -s, allow option stacking even if one
3343                     or more of the options take arguments.  For  example,  if
3344                     -x  takes an argument, with no -s, `-xy' is considered as
3345                     a single (unhandled) option; with -s, -xy  is  an  option
3346                     with  the  argument  `y'; with both -s and -w, -xy is the
3347                     option -x and the option -y with arguments to -x (and  to
3348                     -y,  if  it  takes arguments) still to come in subsequent
3349                     words.
3350
3351              -W     This option takes -w a stage further:  it is possible  to
3352                     complete  single-letter  options  even  after an argument
3353                     that occurs in the same word.  However, it depends on the
3354                     action performed whether options will really be completed
3355                     at this point.  For more control, use a utility  function
3356                     like _guard as part of the action.
3357
3358              -C     Modify the curcontext parameter for an action of the form
3359                     `->state'.  This is discussed in detail below.
3360
3361              -R     Return status 300 instead of zero when a $state is to  be
3362                     handled, in the `->string' syntax.
3363
3364              -S     Do  not  complete  options  after a `--' appearing on the
3365                     line, and ignore the `--'.  For example, with -S, in  the
3366                     line
3367
3368                            foobar -x -- -y
3369
3370                     the  `-x' is considered an option, the `-y' is considered
3371                     an argument, and the `--' is considered to be neither.
3372
3373              -A pat Do not complete options after the first non-option  argu‐
3374                     ment  on the line.  pat is a pattern matching all strings
3375                     which are not to be taken as arguments.  For example,  to
3376                     make  _arguments  stop completing options after the first
3377                     normal argument, but ignoring all strings starting with a
3378                     hyphen  even if they are not described by one of the opt‐
3379                     specs, the form is `-A "-*"'.
3380
3381              -O name
3382                     Pass the elements of the array name as arguments to func‐
3383                     tions  called  to  execute actions.  This is discussed in
3384                     detail below.
3385
3386              -M matchspec
3387                     Use the match specification matchspec for completing  op‐
3388                     tion names and values.  The default matchspec allows par‐
3389                     tial word completion after `_' and `-', such as  complet‐
3390                     ing `-f-b' to `-foo-bar'.  The default matchspec is:
3391                     r:|[_-]=* r:|=*
3392
3393              -0     When  populating values of the `opt_args' associative ar‐
3394                     ray, don't backslash-escape colons  and  backslashes  and
3395                     use  NUL  rather  than colon for joining multiple values.
3396                     This option is described in more detail below, under  the
3397                     heading specs: actions.
3398
3399              specs: overview
3400
3401              Each of the following forms is a spec describing individual sets
3402              of options or arguments on the command line being analyzed.
3403
3404              n:message:action
3405              n::message:action
3406                     This describes the n'th  normal  argument.   The  message
3407                     will  be  printed above the matches generated and the ac‐
3408                     tion indicates what can be  completed  in  this  position
3409                     (see  below).  If there are two colons before the message
3410                     the argument is optional.  If the message  contains  only
3411                     white  space,  nothing  will be printed above the matches
3412                     unless the action adds an explanation string itself.
3413
3414              :message:action
3415              ::message:action
3416                     Similar, but describes the next argument, whatever number
3417                     that  happens  to  be.  If all arguments are specified in
3418                     this form in the correct order the numbers  are  unneces‐
3419                     sary.
3420
3421              *:message:action
3422              *::message:action
3423              *:::message:action
3424                     This  describes  how  arguments (usually non-option argu‐
3425                     ments, those not beginning with - or +) are  to  be  com‐
3426                     pleted  when neither of the first two forms was provided.
3427                     Any number of arguments can be completed in this fashion.
3428
3429                     With two colons before the message, the words special ar‐
3430                     ray and the CURRENT special parameter are modified to re‐
3431                     fer only to the normal arguments when the action is  exe‐
3432                     cuted or evaluated.  With three colons before the message
3433                     they are modified to refer only to the  normal  arguments
3434                     covered by this description.
3435
3436              optspec
3437              optspec:...
3438                     This  describes  an option.  The colon indicates handling
3439                     for one or more arguments to the option;  if  it  is  not
3440                     present, the option is assumed to take no arguments.
3441
3442                     The  following  forms  are available for the initial opt‐
3443                     spec, whether or not the option has arguments.
3444
3445                     *optspec
3446                            Here optspec is one of the remaining forms  below.
3447                            This  indicates  the  following optspec may be re‐
3448                            peated.  Otherwise if the corresponding option  is
3449                            already present on the command line to the left of
3450                            the cursor it will not be offered again.
3451
3452                     -optname
3453                     +optname
3454                            In the simplest form the optspec is just  the  op‐
3455                            tion  name  beginning with a minus or a plus sign,
3456                            such as `-foo'.  The first argument for the option
3457                            (if  any)  must follow as a separate word directly
3458                            after the option.
3459
3460                            Either of `-+optname' and `+-optname' can be  used
3461                            to  specify  that  -optname  and +optname are both
3462                            valid.
3463
3464                            In all the remaining forms, the leading `-' may be
3465                            replaced by or paired with `+' in this way.
3466
3467                     -optname-
3468                            The  first  argument  of  the option must come di‐
3469                            rectly after the option name  in  the  same  word.
3470                            For  example,  `-foo-:...' specifies that the com‐
3471                            pleted  option  and  argument   will   look   like
3472                            `-fooarg'.
3473
3474                     -optname+
3475                            The  first  argument  may appear immediately after
3476                            optname in the same word, or may appear as a sepa‐
3477                            rate   word   after   the  option.   For  example,
3478                            `-foo+:...' specifies that  the  completed  option
3479                            and  argument  will  look like either `-fooarg' or
3480                            `-foo arg'.
3481
3482                     -optname=
3483                            The argument may appear as the next  word,  or  in
3484                            same  word  as the option name provided that it is
3485                            separated from it by an equals sign,  for  example
3486                            `-foo=arg' or `-foo arg'.
3487
3488                     -optname=-
3489                            The  argument  to  the option must appear after an
3490                            equals sign in the same word, and may not be given
3491                            in the next argument.
3492
3493                     optspec[explanation]
3494                            An  explanation  string  may be appended to any of
3495                            the preceding forms of optspec by enclosing it  in
3496                            brackets, as in `-q[query operation]'.
3497
3498                            The  verbose  style  is used to decide whether the
3499                            explanation strings are displayed with the  option
3500                            in a completion listing.
3501
3502                            If  no  bracketed  explanation string is given but
3503                            the auto-description style is set and only one ar‐
3504                            gument is described for this optspec, the value of
3505                            the style is displayed, with any appearance of the
3506                            sequence `%d' in it replaced by the message of the
3507                            first optarg that follows the optspec; see below.
3508
3509                     It is possible for options with a literal `+' or  `='  to
3510                     appear,  but  that  character must be quoted, for example
3511                     `-\+'.
3512
3513                     Each optarg following an optspec must  take  one  of  the
3514                     following forms:
3515
3516                     :message:action
3517                     ::message:action
3518                            An  argument to the option; message and action are
3519                            treated as for ordinary arguments.  In  the  first
3520                            form, the argument is mandatory, and in the second
3521                            form it is optional.
3522
3523                            This group may be repeated for options which  take
3524                            multiple arguments.  In other words, :message1:ac‐
3525                            tion1:message2:action2 specifies that  the  option
3526                            takes two arguments.
3527
3528                     :*pattern:message:action
3529                     :*pattern::message:action
3530                     :*pattern:::message:action
3531                            This  describes multiple arguments.  Only the last
3532                            optarg for an option taking multiple arguments may
3533                            be  given  in  this form.  If the pattern is empty
3534                            (i.e. :*:), all the remaining words  on  the  line
3535                            are  to  be  completed as described by the action;
3536                            otherwise, all the words up  to  and  including  a
3537                            word  matching the pattern are to be completed us‐
3538                            ing the action.
3539
3540                            Multiple colons are treated  as  for  the  `*:...'
3541                            forms for ordinary arguments:  when the message is
3542                            preceded by two colons, the  words  special  array
3543                            and  the  CURRENT  special  parameter are modified
3544                            during the execution or evaluation of  the  action
3545                            to refer only to the words after the option.  When
3546                            preceded by three colons, they are modified to re‐
3547                            fer only to the words covered by this description.
3548
3549              Any literal colon in an optname, message, or action must be pre‐
3550              ceded by a backslash, `\:'.
3551
3552              Each of the forms above may be preceded by a list in parentheses
3553              of option names and argument numbers.  If the given option is on
3554              the command line, the options and arguments indicated in  paren‐
3555              theses   will  not  be  offered.   For  example,  `(-two  -three
3556              1)-one:...' completes the option `-one'; if this appears on  the
3557              command line, the options -two and -three and the first ordinary
3558              argument will not be completed after it.  `(-foo):...' specifies
3559              an  ordinary  argument completion; -foo will not be completed if
3560              that argument is already present.
3561
3562              Other items may appear in the list of excluded options to  indi‐
3563              cate  various  other  items  that should not be applied when the
3564              current specification is matched: a single star (*) for the rest
3565              arguments  (i.e.  a  specification of the form `*:...'); a colon
3566              (:) for all normal (non-option-) arguments; and a hyphen (-) for
3567              all options.  For example, if `(*)' appears before an option and
3568              the option appears on the command line, the  list  of  remaining
3569              arguments  (those  shown in the above table beginning with `*:')
3570              will not be completed.
3571
3572              To aid in reuse of specifications, it is possible to precede any
3573              of  the  forms  above  with `!'; then the form will no longer be
3574              completed, although if the option or  argument  appears  on  the
3575              command  line  they will be skipped as normal.  The main use for
3576              this is when the arguments are given by an array, and _arguments
3577              is  called  repeatedly  for more specific contexts: on the first
3578              call `_arguments $global_options' is  used,  and  on  subsequent
3579              calls `_arguments !$^global_options'.
3580
3581              specs: actions
3582
3583
3584              In each of the forms above the action determines how completions
3585              should be generated.  Except for the `->string' form below,  the
3586              action  will  be executed by calling the _all_labels function to
3587              process all tag labels.  No special handling of tags  is  needed
3588              unless a function call introduces a new one.
3589
3590              The  functions called to execute actions will be called with the
3591              elements of the array named by the `-O  name'  option  as  argu‐
3592              ments.   This  can be used, for example, to pass the same set of
3593              options for the compadd builtin to all actions.
3594
3595              The forms for action are as follows.
3596
3597               (single unquoted space)
3598                     This is useful where an argument is required  but  it  is
3599                     not  possible  or  desirable  to generate matches for it.
3600                     The message will be displayed but no completions  listed.
3601                     Note  that  even in this case the colon at the end of the
3602                     message is needed; it may only be omitted when neither  a
3603                     message nor an action is given.
3604
3605              (item1 item2 ...)
3606                     One of a list of possible matches, for example:
3607
3608                            :foo:(foo bar baz)
3609
3610              ((item1\:desc1 ...))
3611                     Similar to the above, but with descriptions for each pos‐
3612                     sible match.  Note the backslash before the  colon.   For
3613                     example,
3614
3615                            :foo:((a\:bar b\:baz))
3616
3617                     The  matches  will be listed together with their descrip‐
3618                     tions if the description style is set with the values tag
3619                     in the context.
3620
3621              ->string
3622                     In  this form, _arguments processes the arguments and op‐
3623                     tions and then returns control to  the  calling  function
3624                     with  parameters set to indicate the state of processing;
3625                     the calling function then makes its own arrangements  for
3626                     generating  completions.  For example, functions that im‐
3627                     plement a state machine can use this type of action.
3628
3629                     Where _arguments encounters action in the `->string' for‐
3630                     mat,  it  will  strip all leading and trailing whitespace
3631                     from string and set the array state to  the  set  of  all
3632                     strings for which an action is to be performed.  The ele‐
3633                     ments of the array state_descr are  assigned  the  corre‐
3634                     sponding  message  field from each optarg containing such
3635                     an action.
3636
3637                     By default and in common with all other well behaved com‐
3638                     pletion  functions,  _arguments returns status zero if it
3639                     was able to add matches and non-zero otherwise.  However,
3640                     if the -R option is given, _arguments will instead return
3641                     a status of 300 to indicate that $state is to be handled.
3642
3643                     In addition to $state and $state_descr,  _arguments  also
3644                     sets   the   global   parameters  `context',  `line'  and
3645                     `opt_args' as described below, and  does  not  reset  any
3646                     changes made to the special parameters such as PREFIX and
3647                     words.  This gives the calling function the choice of re‐
3648                     setting these parameters or propagating changes in them.
3649
3650                     A  function  calling  _arguments with at least one action
3651                     containing a `->string' must therefore declare  appropri‐
3652                     ate local parameters:
3653
3654                            local context state state_descr line
3655                            typeset -A opt_args
3656
3657                     to  prevent  _arguments from altering the global environ‐
3658                     ment.
3659
3660              {eval-string}
3661                     A string in braces is evaluated as shell code to generate
3662                     matches.   If  the eval-string itself does not begin with
3663                     an opening parenthesis or brace it is split into separate
3664                     words before execution.
3665
3666              = action
3667                     If  the  action starts with `= ' (an equals sign followed
3668                     by a space), _arguments will insert the contents  of  the
3669                     argument  field  of  the current context as the new first
3670                     element in the words  special  array  and  increment  the
3671                     value of the CURRENT special parameter.  This has the ef‐
3672                     fect of inserting a dummy word onto the  completion  com‐
3673                     mand  line  while not changing the point at which comple‐
3674                     tion is taking place.
3675
3676                     This is most useful with one of the specifiers  that  re‐
3677                     strict  the words on the command line on which the action
3678                     is to operate (the two-  and  three-colon  forms  above).
3679                     One particular use is when an action itself causes _argu‐
3680                     ments on a restricted range; it is necessary to use  this
3681                     trick  to  insert  an  appropriate  command name into the
3682                     range for the second call to _arguments  to  be  able  to
3683                     parse the line.
3684
3685               word...
3686              word...
3687                     This covers all forms other than those above.  If the ac‐
3688                     tion starts with a space, the  remaining  list  of  words
3689                     will be invoked unchanged.
3690
3691                     Otherwise  it  will  be  invoked  with some extra strings
3692                     placed after the first word; these are to be passed  down
3693                     as  options to the compadd builtin.  They ensure that the
3694                     state specified by _arguments, in particular the descrip‐
3695                     tions  of  options  and arguments, is correctly passed to
3696                     the completion command.  These additional  arguments  are
3697                     taken  from  the array parameter `expl'; this will be set
3698                     up before executing the action and hence may be  referred
3699                     to  inside  it,  typically  in  an  expansion of the form
3700                     `$expl[@]' which preserves empty elements of the array.
3701
3702              During the performance of the action the array  `line'  will  be
3703              set  to  the  normal  arguments  from the command line, i.e. the
3704              words from the command line after the command name excluding all
3705              options and their arguments.  Options are stored in the associa‐
3706              tive array `opt_args' with option names as keys and their  argu‐
3707              ments  as the values.  By default, all colons and backslashes in
3708              the value are escaped with backslashes, and  if  an  option  has
3709              multiple  arguments  (for  example, when using an optspec of the
3710              form `*optspec'), they are joined with (unescaped) colons.  How‐
3711              ever, if the -0 option was passed, no backslash escaping is per‐
3712              formed, and multiple values are joined with NUL bytes.  For  ex‐
3713              ample,  after `zsh -o foo:foo -o bar:bar -o <TAB>', the contents
3714              of `opt_args' would be
3715
3716                     typeset -A opt_args=( [-o]='foo\:foo:bar\:bar:' )
3717
3718              by default, and
3719
3720                     typeset -A opt_args=( [-o]=$'foo:foo\x00bar:bar\x00' )
3721
3722              if _arguments had been called with the -0 option.
3723
3724              The parameter `context' is set when  returning  to  the  calling
3725              function to perform an action of the form `->string'.  It is set
3726              to an array of elements corresponding to the elements of $state.
3727              Each  element  is  a suitable name for the argument field of the
3728              context: either a string of the form `option-opt-n' for the n'th
3729              argument  of  the  option  -opt,  or a string of the form `argu‐
3730              ment-n' for the n'th argument.  For `rest'  arguments,  that  is
3731              those  in  the list at the end not handled by position, n is the
3732              string `rest'.  For example, when completing the argument of the
3733              -o option, the name is `option-o-1', while for the second normal
3734              (non-option-) argument it is `argument-2'.
3735
3736              Furthermore, during the evaluation of  the  action  the  context
3737              name  in  the curcontext parameter is altered to append the same
3738              string that is stored in the context parameter.
3739
3740              The option -C tells _arguments to modify the curcontext  parame‐
3741              ter  for  an action of the form `->state'.  This is the standard
3742              parameter used to keep track of the current  context.   Here  it
3743              (and  not the context array) should be made local to the calling
3744              function to avoid passing back the modified value and should  be
3745              initialised to the current value at the start of the function:
3746
3747                     local curcontext="$curcontext"
3748
3749              This  is  useful where it is not possible for multiple states to
3750              be valid together.
3751
3752              Grouping Options
3753
3754              Options can be grouped to simplify exclusion lists. A  group  is
3755              introduced with `+' followed by a name for the group in the sub‐
3756              sequent word. Whole groups can then be referenced in  an  exclu‐
3757              sion  list  or  a group name can be used to disambiguate between
3758              two forms of the same option. For example:
3759
3760                     _arguments \
3761                         '(group2--x)-a' \
3762                       + group1 \
3763                         -m \
3764                         '(group2)-n' \
3765                       + group2 \
3766                         -x -y
3767
3768              If the name of a group is specified in the  form  `(name)'  then
3769              only one value from that group will ever be completed; more for‐
3770              mally, all specifications are mutually exclusive  to  all  other
3771              specifications  in  that  group. This is useful for defining op‐
3772              tions that are aliases for each other. For example:
3773
3774                     _arguments \
3775                         -a -b \
3776                       + '(operation)' \
3777                         {-c,--compress}'[compress]' \
3778                         {-d,--decompress}'[decompress]' \
3779                         {-l,--list}'[list]'
3780
3781              If an option in a group appears  on  the  command  line,  it  is
3782              stored  in  the associative array `opt_args' with 'group-option'
3783              as a key.  In the example above, a key `operation--c' is used if
3784              the option `-c' is present on the command line.
3785
3786              Specifying Multiple Sets of Arguments
3787
3788              It is possible to specify multiple sets of options and arguments
3789              with the sets separated by single  hyphens.  This  differs  from
3790              groups  in  that sets are considered to be mutually exclusive of
3791              each other.
3792
3793              Specifications before the first set and from any group are  com‐
3794              mon to all sets. For example:
3795
3796                     _arguments \
3797                         -a \
3798                       - set1 \
3799                         -c \
3800                       - set2 \
3801                         -d \
3802                         ':arg:(x2 y2)'
3803
3804              This  defines  two sets.  When the command line contains the op‐
3805              tion `-c', the `-d' option and the argument will not be  consid‐
3806              ered  possible  completions.   When it contains `-d' or an argu‐
3807              ment, the option `-c' will not be  considered.   However,  after
3808              `-a' both sets will still be considered valid.
3809
3810              As  for groups, the name of a set may appear in exclusion lists,
3811              either alone or preceding a normal option or argument specifica‐
3812              tion.
3813
3814              The completion code has to parse the command line separately for
3815              each set. This can be slow so sets should only be used when nec‐
3816              essary.   A  useful alternative is often an option specification
3817              with rest-arguments (as in `-foo:*:...'); here the  option  -foo
3818              swallows  up  all remaining arguments as described by the optarg
3819              definitions.
3820
3821              Deriving spec forms from the help output
3822
3823              The option `--' allows _arguments to work out the names of  long
3824              options  that  support  the `--help' option which is standard in
3825              many GNU commands.  The command word is called with the argument
3826              `--help'  and the output examined for option names.  Clearly, it
3827              can be dangerous to pass this to commands which may not  support
3828              this option as the behaviour of the command is unspecified.
3829
3830              In  addition  to options, `_arguments --' will try to deduce the
3831              types  of  arguments  available  for  options  when   the   form
3832              `--opt=val'  is  valid.  It is also possible to provide hints by
3833              examining the help text of the command and  adding  helpspec  of
3834              the  form  `pattern:message:action';  note that other _arguments
3835              spec forms are not used.  The pattern  is  matched  against  the
3836              help  text  for an option, and if it matches the message and ac‐
3837              tion are used as for other  argument  specifiers.   The  special
3838              case  of `*:' means both message and action are empty, which has
3839              the effect of causing options having no description in the  help
3840              output  to  be  ordered in listings ahead of options that have a
3841              description.
3842
3843              For example:
3844
3845                     _arguments -- '*\*:toggle:(yes no)' \
3846                                   '*=FILE*:file:_files' \
3847                                   '*=DIR*:directory:_files -/' \
3848                                   '*=PATH*:directory:_files -/'
3849
3850              Here, `yes' and `no' will be completed as the  argument  of  op‐
3851              tions  whose description ends in a star; file names will be com‐
3852              pleted for options that contain the substring `=FILE' in the de‐
3853              scription;  and  directories will be completed for options whose
3854              description contains `=DIR' or `=PATH'.  The last three  are  in
3855              fact  the  default and so need not be given explicitly, although
3856              it is possible to override the use of these patterns.  A typical
3857              help text which uses this feature is:
3858
3859                       -C, --directory=DIR          change to directory DIR
3860
3861              so  that  the  above specifications will cause directories to be
3862              completed after `--directory', though not after `-C'.
3863
3864              Note also that _arguments tries to find out automatically if the
3865              argument  for  an option is optional.  This can be specified ex‐
3866              plicitly by doubling the colon before the message.
3867
3868              If the pattern ends in `(-)', this will be removed from the pat‐
3869              tern  and  the  action will be used only directly after the `=',
3870              not in the next word.  This is the behaviour of a normal  speci‐
3871              fication defined with the form `=-'.
3872
3873              By  default, the command (with the option `--help') is run after
3874              resetting all the locale categories  (except  for  LC_CTYPE)  to
3875              `C'.   If the localized help output is known to work, the option
3876              `-l' can be specified after the `_arguments --' so that the com‐
3877              mand is run in the current locale.
3878
3879              The  `_arguments --' can be followed by the option `-i patterns'
3880              to give patterns for options which are not to be completed.  The
3881              patterns  can be given as the name of an array parameter or as a
3882              literal list in parentheses.  For example,
3883
3884                     _arguments -- -i \
3885                         "(--(en|dis)able-FEATURE*)"
3886
3887              will cause completion to ignore the  options  `--enable-FEATURE'
3888              and `--disable-FEATURE' (this example is useful with GNU config‐
3889              ure).
3890
3891              The `_arguments --' form can also be followed by the option  `-s
3892              pair'  to  describe option aliases.  The pair consists of a list
3893              of alternating patterns and corresponding replacements, enclosed
3894              in  parens and quoted so that it forms a single argument word in
3895              the _arguments call.
3896
3897              For example, some configure-script help output describes options
3898              only  as `--enable-foo', but the script also accepts the negated
3899              form `--disable-foo'.  To allow completion of the second form:
3900
3901                     _arguments -- -s "((#s)--enable- --disable-)"
3902
3903              Miscellaneous notes
3904
3905              Finally, note that _arguments generally expects to be  the  pri‐
3906              mary  function handling any completion for which it is used.  It
3907              may have side effects which change the treatment of any  matches
3908              added by other functions called after it.  To combine _arguments
3909              with other functions, those functions should  be  called  either
3910              before  _arguments,  as  an action within a spec, or in handlers
3911              for `->state' actions.
3912
3913              Here is a more general example of the use of _arguments:
3914
3915                     _arguments '-l+:left border:' \
3916                                '-format:paper size:(letter A4)' \
3917                                '*-copy:output file:_files::resolution:(300 600)' \
3918                                ':postscript file:_files -g \*.\(ps\|eps\)' \
3919                                '*:page number:'
3920
3921              This describes three options: `-l', `-format', and `-copy'.  The
3922              first takes one argument described as `left border' for which no
3923              completion will be offered because of the empty action.  Its ar‐
3924              gument  may  come  directly after the `-l' or it may be given as
3925              the next word on the line.
3926
3927              The `-format' option takes one argument in the  next  word,  de‐
3928              scribed  as `paper size' for which only the strings `letter' and
3929              `A4' will be completed.
3930
3931              The `-copy' option may appear more than once on the command line
3932              and  takes  two  arguments.   The first is mandatory and will be
3933              completed as a filename.  The second is optional (because of the
3934              second  colon  before  the description `resolution') and will be
3935              completed from the strings `300' and `600'.
3936
3937              The last two descriptions say what should be completed as  argu‐
3938              ments.   The first describes the first argument as a `postscript
3939              file' and makes files ending in `ps' or `eps' be completed.  The
3940              last description gives all other arguments the description `page
3941              number' but does not offer completions.
3942
3943       _cache_invalid cache_identifier
3944              This function returns status zero if the completions cache  cor‐
3945              responding  to  the given cache identifier needs rebuilding.  It
3946              determines this by looking up the  cache-policy  style  for  the
3947              current  context.   This should provide a function name which is
3948              run with the full path to the relevant cache file  as  the  only
3949              argument.
3950
3951              Example:
3952
3953                     _example_caching_policy () {
3954                         # rebuild if cache is more than a week old
3955                         local -a oldp
3956                         oldp=( "$1"(Nm+7) )
3957                         (( $#oldp ))
3958                     }
3959
3960       _call_function return name [ arg ... ]
3961              If a function name exists, it is called with the arguments args.
3962              The return argument gives the name of a parameter in  which  the
3963              return status from the function name should be stored; if return
3964              is empty or a single hyphen it is ignored.
3965
3966              The return status of _call_function itself is zero if the  func‐
3967              tion name exists and was called and non-zero otherwise.
3968
3969       _call_program [ -l ] [ -p ] tag string ...
3970              This  function provides a mechanism for the user to override the
3971              use of an external command.  It looks up the command style  with
3972              the supplied tag.  If the style is set, its value is used as the
3973              command to execute.  The strings from the call to _call_program,
3974              or  from  the style if set, are concatenated with spaces between
3975              them and the resulting string is evaluated.  The  return  status
3976              is the return status of the command called.
3977
3978              By  default,  the command is run in an environment where all the
3979              locale categories (except for LC_CTYPE)  are  reset  to  `C'  by
3980              calling  the  utility  function _comp_locale (see below). If the
3981              option `-l' is given, the command is run with  the  current  lo‐
3982              cale.
3983
3984              If  the  option  `-p'  is supplied it indicates that the command
3985              output is influenced by the permissions it is run with.  If  the
3986              gain-privileges  style  is  set to true, _call_program will make
3987              use of commands such as sudo, if present on the command-line, to
3988              match the permissions to whatever the final command is likely to
3989              run under. When  looking  up  the  gain-privileges  and  command
3990              styles,  the  command  component  of the zstyle context will end
3991              with a slash (`/') followed by the command that would be used to
3992              gain privileges.
3993
3994       _combination [ -s pattern ] tag style spec ... field opts ...
3995              This  function  is used to complete combinations of values,  for
3996              example pairs of hostnames and usernames.   The  style  argument
3997              gives  the  style  which defines the pairs; it is looked up in a
3998              context with the tag specified.
3999
4000              The style name consists of field names separated by hyphens, for
4001              example  `users-hosts-ports'.  For each field for a value is al‐
4002              ready known, a spec of the form `field=pattern' is  given.   For
4003              example,  if the command line so far specifies a user `pws', the
4004              argument `users=pws' should appear.
4005
4006              The next argument with no equals sign is taken as  the  name  of
4007              the  field for which completions should be generated (presumably
4008              not one of the fields for which the value is known).
4009
4010              The matches generated will be taken from the value of the style.
4011              These should contain the possible values for the combinations in
4012              the appropriate  order  (users,  hosts,  ports  in  the  example
4013              above).   The  values  for the different fields are separated by
4014              colons.  This can be altered with the option -s to  _combination
4015              which specifies a pattern.  Typically this is a character class,
4016              as for example `-s "[:@]"' in the case of the users-hosts style.
4017              Each  `field=pattern'  specification  restricts  the completions
4018              which apply to elements of the style with appropriately matching
4019              fields.
4020
4021              If no style with the given name is defined for the given tag, or
4022              if none of the strings in style's value match,  but  a  function
4023              name of the required field preceded by an underscore is defined,
4024              that function will be called to generate the matches.  For exam‐
4025              ple,  if there is no `users-hosts-ports' or no matching hostname
4026              when a host is required, the function  `_hosts'  will  automati‐
4027              cally be called.
4028
4029              If  the  same  name is used for more than one field, in both the
4030              `field=pattern' and the argument that  gives  the  name  of  the
4031              field  to  be  completed, the number of the field (starting with
4032              one) may be given after the fieldname, separated from  it  by  a
4033              colon.
4034
4035              All  arguments  after the required field name are passed to com‐
4036              padd when generating matches from the style  value,  or  to  the
4037              functions for the fields if they are called.
4038
4039       _command_names [ -e | - ]
4040              This  function  completes  words that are valid at command posi‐
4041              tion: names of aliases, builtins,  hashed  commands,  functions,
4042              and  so  on.   With  the  -e flag, only hashed commands are com‐
4043              pleted.  The - flag is ignored.
4044
4045       _comp_locale
4046              This function  resets  all  the  locale  categories  other  than
4047              LC_CTYPE to `C' so that the output from external commands can be
4048              easily analyzed by the completion system. LC_CTYPE  retains  the
4049              current  value  (taking  LC_ALL and LANG into account), ensuring
4050              that non-ASCII characters in file names are still handled  prop‐
4051              erly.
4052
4053              This function should normally be run only in a subshell, because
4054              the new locale is exported to  the  environment.  Typical  usage
4055              would be `$(_comp_locale; command ...)'.
4056
4057       _completers [ -p ]
4058              This function completes names of completers.
4059
4060              -p     Include the leading underscore (`_') in the matches.
4061
4062       _default
4063              This function corresponds to the -default- special context which
4064              is applied where no completion is defined.  It is useful to call
4065              it  under  certain  error conditions such as completion after an
4066              unrecognised subcommand.  This applies the concept  of  graceful
4067              degradation to the completion system, allowing it to fallback on
4068              basic completion of commonly useful things like filenames.
4069
4070
4071       _describe [-12JVx] [ -oO | -t tag ] descr name1 [ name2 ] [ opt ... ]
4072                 [ -- name1 [ name2 ] [ opt ... ] ... ]
4073              This function associates completions with descriptions.   Multi‐
4074              ple  groups  separated  by  -- can be supplied, potentially with
4075              different completion options opts.
4076
4077              The descr is taken as a string to display above the  matches  if
4078              the  format style for the descriptions tag is set.  This is fol‐
4079              lowed by one or two names of arrays followed by options to  pass
4080              to  compadd.   The array name1 contains the possible completions
4081              with their descriptions in  the  form  `completion:description'.
4082              Any  literal  colons  in  completion must be quoted with a back‐
4083              slash.  If a name2 is given, it should have the same  number  of
4084              elements  as  name1; in this case the corresponding elements are
4085              added as possible completions instead of the completion  strings
4086              from  name1.   The  completion list will retain the descriptions
4087              from name1.  Finally, a set of completion options can appear.
4088
4089              If the option  `-o'  appears  before  the  first  argument,  the
4090              matches  added will be treated as names of command options (N.B.
4091              not shell options), typically following a `-', `--'  or  `+'  on
4092              the  command  line.  In this case _describe uses the prefix-hid‐
4093              den, prefix-needed and verbose styles to find out if the strings
4094              should be added as completions and if the descriptions should be
4095              shown.  Without the `-o' option, only the verbose style is  used
4096              to  decide  how descriptions are shown.  If `-O' is used instead
4097              of `-o', command options are completed as  above  but  _describe
4098              will not handle the prefix-needed style.
4099
4100              With the -t option a tag can be specified.  The default is `val‐
4101              ues' or, if the -o option is given, `options'.
4102
4103              The options -1, -2, -J, -V, -x are passed to _next_label.
4104
4105              If selected by the list-grouped style, strings with the same de‐
4106              scription will appear together in the list.
4107
4108              _describe uses the _all_labels function to generate the matches,
4109              so it does not need to appear inside a loop over tag labels.
4110
4111       _description [ -x ] [ -12VJ ] tag name descr [ spec ... ]
4112              This function is not to be confused with the previous one; it is
4113              used  as  a helper function for creating options to compadd.  It
4114              is buried inside many of the higher level  completion  functions
4115              and so often does not need to be called directly.
4116
4117              The  styles listed below are tested in the current context using
4118              the given tag.  The resulting options for compadd are  put  into
4119              the  array  named  name  (this is traditionally `expl', but this
4120              convention is not enforced).  The  description  for  the  corre‐
4121              sponding set of matches is passed to the function in descr.
4122
4123              The styles tested are: format, hidden, matcher, ignore-line, ig‐
4124              nored-patterns, group-name and sort.  The format style is  first
4125              tested for the given tag and then for the descriptions tag if no
4126              value was found, while the remainder are only tested for the tag
4127              given  as  the  first  argument.  The function also calls _setup
4128              which tests some more styles.
4129
4130              The string returned by the format style (if any) will  be  modi‐
4131              fied so that the sequence `%d' is replaced by the descr given as
4132              the third argument without any leading or trailing white  space.
4133              If,  after  removing  the  white  space,  the descr is the empty
4134              string, the format style will not be used and  the  options  put
4135              into the name array will not contain an explanation string to be
4136              displayed above the matches.
4137
4138              If _description is called with more than  three  arguments,  the
4139              additional specs should be of the form `char:str'.  These supply
4140              escape sequence replacements for the format style: every appear‐
4141              ance  of  `%char'  will be replaced by string.  If no additional
4142              specs are given but the description in descr conforms to a  com‐
4143              mon  form  then further escape sequences are set for elements of
4144              that description.  These elements correspond to a default  value
4145              (`%o'),  the  units (`%m') range of acceptable values (`%r') and
4146              the remaining initial part of the description (`%h').  The  form
4147              the description takes consists of specifying the units and range
4148              in parentheses and the default value in square brackets, for ex‐
4149              ample:
4150
4151                     _description times expl 'timeout (seconds) (0-60) [20]'
4152
4153              It  is  possible  to  use  zformat  conditional expressions when
4154              styling these elements. So, for example, to add `default:' as  a
4155              tag  but  only when there is a default value to show, the format
4156              style might include `%(o.default: %o.)'.
4157
4158              If the -x option is given, the description  will  be  passed  to
4159              compadd  using  the  -x  option instead of the default -X.  This
4160              means that the description will be displayed even if  there  are
4161              no corresponding matches.
4162
4163              The  options  placed  in  the  array  name  take  account of the
4164              group-name style, so matches are  placed  in  a  separate  group
4165              where necessary.  The group normally has its elements sorted (by
4166              passing the option -J to compadd), but  if  an  option  starting
4167              with  `-V',  `-J', `-1', or `-2' is passed to _description, that
4168              option will be included in the array.  Hence it is possible  for
4169              the  completion  group to be unsorted by giving the option `-V',
4170              `-1V', or `-2V'.
4171
4172              In most cases, the function will be used like this:
4173
4174                     local expl
4175                     _description files expl file
4176                     compadd "$expl[@]" - "$files[@]"
4177
4178              Note the use of the parameter expl, the hyphen, and the list  of
4179              matches.  Almost all calls to compadd within the completion sys‐
4180              tem use a  similar  format;  this  ensures  that  user-specified
4181              styles are correctly passed down to the builtins which implement
4182              the internals of completion.
4183
4184       _dir_list [ -s sep ] [ -S ]
4185              Complete a list of directory names separated by colons (the same
4186              format as $PATH).
4187
4188              -s sep Use  sep  as  separator between items.  sep defaults to a
4189                     colon (`:').
4190
4191              -S     Add sep instead of slash (`/') as an autoremoveable  suf‐
4192                     fix.
4193
4194       _dispatch context string ...
4195              This  sets  the current context to context and looks for comple‐
4196              tion functions to handle this context  by  hunting  through  the
4197              list  of  command  names or special contexts (as described above
4198              for compdef) given as strings.  The first completion function to
4199              be defined for one of the contexts in the list is used to gener‐
4200              ate matches.  Typically, the last string is -default-  to  cause
4201              the function for default completion to be used as a fallback.
4202
4203              The  function  sets  the  parameter $service to the string being
4204              tried, and sets the context/command field (the  fourth)  of  the
4205              $curcontext  parameter  to  the context given as the first argu‐
4206              ment.
4207
4208       _email_addresses [ -c ] [ -n plugin ]
4209              Complete email addresses.  Addresses are provided by plugins.
4210
4211              -c     Complete bare localhost@domain.tld addresses,  without  a
4212                     name  part  or  a  comment.   Without this option, RFC822
4213                     `Firstname Lastname <address>' strings are completed.
4214
4215              -n plugin
4216                     Complete aliases from plugin.
4217
4218              The following plugins are available by default: _email-ldap (see
4219              the  filter  style),  _email-local (completes user@hostname Unix
4220              addresses),  _email-mail  (completes  aliases  from  ~/.mailrc),
4221              _email-mush, _email-mutt, and _email-pine.
4222
4223              Addresses  from  the  _email-foo  plugin are added under the tag
4224              `email-foo'.
4225
4226              Writing plugins
4227
4228              Plugins are written as separate functions  with  names  starting
4229              with `_email-'.  They are invoked with the -c option and compadd
4230              options.  They should either do their own completion or set  the
4231              $reply  array  to  a list of `alias:address' elements and return
4232              300.  New plugins will be picked up and run automatically.
4233
4234       _files The function _files is a wrapper around _path_files. It supports
4235              all  of  the  same  functionality, with some enhancements -- no‐
4236              tably, it respects the  list-dirs-first  style,  and  it  allows
4237              users  to  override  the behaviour of the -g and -/ options with
4238              the file-patterns style. _files should  therefore  be  preferred
4239              over _path_files in most cases.
4240
4241              This  function  accepts  the  full  set  of  options  allowed by
4242              _path_files, described below.
4243
4244       _gnu_generic
4245              This function is a simple wrapper around the _arguments function
4246              described  above.  It can be used to determine automatically the
4247              long options understood by commands that  produce  a  list  when
4248              passed  the  option  `--help'.   It  is intended to be used as a
4249              top-level completion function in its own right.  For example, to
4250              enable option completion for the commands foo and bar, use
4251
4252                     compdef _gnu_generic foo bar
4253
4254              after the call to compinit.
4255
4256              The  completion system as supplied is conservative in its use of
4257              this function, since it is important to be sure the command  un‐
4258              derstands the option `--help'.
4259
4260       _guard [ options ] pattern descr
4261              This function displays descr if pattern matches the string to be
4262              completed.  It is intended to be used  in  the  action  for  the
4263              specifications passed to _arguments and similar functions.
4264
4265              The  return  status is zero if the message was displayed and the
4266              word to complete is not empty, and non-zero otherwise.
4267
4268              The pattern may be preceded by any of the options understood  by
4269              compadd  that  are passed down from _description, namely -M, -J,
4270              -V, -1, -2, -n, -F and -X.  All of these  options  will  be  ig‐
4271              nored.  This fits in conveniently with the argument-passing con‐
4272              ventions of actions for _arguments.
4273
4274              As an example, consider a command  taking  the  options  -n  and
4275              -none,  where -n must be followed by a numeric value in the same
4276              word.  By using:
4277
4278                     _arguments '-n-: :_guard "[0-9]#" "numeric value"' '-none'
4279
4280              _arguments can be made to  both  display  the  message  `numeric
4281              value' and complete options after `-n<TAB>'.  If the `-n' is al‐
4282              ready followed by one or more  digits  (the  pattern  passed  to
4283              _guard)  only the message will be displayed; if the `-n' is fol‐
4284              lowed by another character, only options are completed.
4285
4286       _message [ -r12 ] [ -VJ group ] descr
4287       _message -e [ tag ] descr
4288              The descr is used in the same way as the third argument  to  the
4289              _description function, except that the resulting string will al‐
4290              ways be shown whether or not matches were  generated.   This  is
4291              useful  for displaying a help message in places where no comple‐
4292              tions can be generated.
4293
4294              The format style is examined with the messages  tag  to  find  a
4295              message;  the usual tag, descriptions, is used only if the style
4296              is not set with the former.
4297
4298              If the -r option is given, no style is used; the descr is  taken
4299              literally  as  the  string to display.  This is most useful when
4300              the descr comes from a pre-processed argument list which already
4301              contains  an  expanded  description.  Note that this option does
4302              not disable the `%'-sequence parsing done by compadd.
4303
4304              The -12VJ options and the group are passed to compadd and  hence
4305              determine the group the message string is added to.
4306
4307              The  second -e form gives a description for completions with the
4308              tag tag to be shown even if there are no matches for  that  tag.
4309              This  form is called by _arguments in the event that there is no
4310              action for an option specification.  The tag can be omitted  and
4311              if so the tag is taken from the parameter $curtag; this is main‐
4312              tained by the completion system and so is usually correct.  Note
4313              that  if  there  are  no  matches  at  the time this function is
4314              called, compstate[insert] is cleared, so additional matches gen‐
4315              erated later are not inserted on the command line.
4316
4317       _multi_parts [ -i ] sep array
4318              The argument sep is a separator character.  The array may be ei‐
4319              ther the name of an array parameter or a literal  array  in  the
4320              form  `(foo  bar)',  a  parenthesised list of words separated by
4321              whitespace.  The possible completions are the strings  from  the
4322              array.   However,  each chunk delimited by sep will be completed
4323              separately.  For example, the _tar function uses `_multi_parts /
4324              patharray'  to  complete partial file paths from the given array
4325              of complete file paths.
4326
4327              The -i option causes _multi_parts to insert a unique match  even
4328              if  that  requires  multiple separators to be inserted.  This is
4329              not usually the expected behaviour with filenames,  but  certain
4330              other types of completion, for example those with a fixed set of
4331              possibilities, may be more suited to this form.
4332
4333              Like other utility functions, this function  accepts  the  `-V',
4334              `-J',  `-1',  `-2',  `-n',  `-f',  `-X', `-M', `-P', `-S', `-r',
4335              `-R', and `-q' options and passes them to the compadd builtin.
4336
4337       _next_label [ -x ] [ -12VJ ] tag name descr [ option ... ]
4338              This function is used to implement the loop over  different  tag
4339              labels for a particular tag as described above for the tag-order
4340              style.  On each call it checks to see if there are any more  tag
4341              labels;  if there is it returns status zero, otherwise non-zero.
4342              As this function requires a current tag to be set, it  must  al‐
4343              ways follow a call to _tags or _requested.
4344
4345              The  -x12VJ  options and the first three arguments are passed to
4346              the _description function.  Where appropriate the  tag  will  be
4347              replaced  by a tag label in this call.  Any description given in
4348              the  tag-order  style  is  preferred  to  the  descr  passed  to
4349              _next_label.
4350
4351              The options given after the descr are set in the parameter given
4352              by name, and hence are to be passed to compadd or whatever func‐
4353              tion is called to add the matches.
4354
4355              Here  is  a  typical  use of this function for the tag foo.  The
4356              call to _requested determines if tag foo is required at all; the
4357              loop  over _next_label handles any labels defined for the tag in
4358              the tag-order style.
4359
4360                     local expl ret=1
4361                     ...
4362                     if _requested foo; then
4363                       ...
4364                       while _next_label foo expl '...'; do
4365                         compadd "$expl[@]" ... && ret=0
4366                       done
4367                       ...
4368                     fi
4369                     return ret
4370
4371       _normal [ -P | -p precommand ]
4372              This is the standard function called to handle  completion  out‐
4373              side  any  special -context-.  It is called both to complete the
4374              command word and also the arguments for a command.  In the  sec‐
4375              ond  case,  _normal looks for a special completion for that com‐
4376              mand, and if there is none it uses the completion for  the  -de‐
4377              fault- context.
4378
4379              A  second  use is to reexamine the command line specified by the
4380              $words array and the $CURRENT parameter after  those  have  been
4381              modified.   For  example,  the  function _precommand, which com‐
4382              pletes after precommand specifiers such as  nohup,  removes  the
4383              first  word from the words array, decrements the CURRENT parame‐
4384              ter, then calls `_normal -p $service'.  The effect is that  `no‐
4385              hup cmd ...' is treated in the same way as `cmd ...'.
4386
4387              -P     Reset the list of precommands. This option should be used
4388                     if completing a command line which allows  internal  com‐
4389                     mands  (e.g.  builtins and functions) regardless of prior
4390                     precommands (e.g. `zsh -c').
4391
4392              -p precommand
4393                     Append precommand to the list of precommands. This option
4394                     should be used in nearly all cases in which -P is not ap‐
4395                     plicable.
4396
4397              If the command name matches one of the patterns given by one  of
4398              the  options  -p  or -P to compdef, the corresponding completion
4399              function is called and then the parameter _compskip is  checked.
4400              If  it  is set completion is terminated at that point even if no
4401              matches have been found.  This is the  same  effect  as  in  the
4402              -first- context.
4403
4404       _numbers [ option ... ] [ description ] [ suffix ... ]
4405              This can be used where a number is followed by a suffix to indi‐
4406              cate the units.  The unit suffixes are completed and can also be
4407              included  in the description used when completion is invoked for
4408              the preceding number.
4409
4410              In addition to common compadd options, _numbers accepts the fol‐
4411              lowing options:
4412
4413              -t tag Specify a tag to use instead of the default of numbers.
4414
4415              -u units
4416                     Indicate the default units for the number, e.g. bytes.
4417
4418              -l min Specify the lowest possible value for the number.
4419
4420              -m max Specify the highest possible value for the number.
4421
4422              -d default
4423                     Specify the default value.
4424
4425              -N     Allow negative numbers.  This is implied if the range in‐
4426                     cludes a negative.
4427
4428              -f     Allow decimal numbers.
4429
4430              Where a particular suffix represents the  default  units  for  a
4431              number,  it should be prefixed with a colon.  Additionally, suf‐
4432              fixes can be followed by a colon and a description.  So for  ex‐
4433              ample,  the  following  allows the age of something to be speci‐
4434              fied, either in seconds or with an optional suffix with a longer
4435              unit of time:
4436
4437                     _numbers -u seconds age :s:seconds m:minutes h:hours d:days
4438
4439              It  is  typically  helpful for units to be presented in order of
4440              magnitude when completed.  To  facilitate  this,  the  order  in
4441              which they are given is preserved.
4442
4443              When  the format style is looked up with the descriptions tag or
4444              the tag specified with -t, the list of suffixes is available  as
4445              a  `%x'  escape  sequence.  This is in addition to the usual se‐
4446              quences documented under the format style. The  form  this  list
4447              takes  can  also be configured. To this end, the format style is
4448              first looked up with the tag unit-suffixes. The retrieved format
4449              is  applied to each suffix in turn and the results are then con‐
4450              catenated to form the completed list. For the unit-suffixes for‐
4451              mat,  `%x'  expands to the individual suffix and `%X' to its de‐
4452              scription. %d' indicates a default suffix and can be used  in  a
4453              condition.  The index and reverse index are set in `%i' and `%r'
4454              respectively and are useful for  text  included  only  with  the
4455              first and last suffixes in the list. So for example, the follow‐
4456              ing joins the suffixes together as a comma-separated list:
4457
4458                     zstyle ':completion:*:unit-suffixes' format '%x%(r::,)'
4459
4460       _options
4461              This can be used to complete the names  of  shell  options.   It
4462              provides  a  matcher  specification that ignores a leading `no',
4463              ignores underscores and allows upper-case letters to match their
4464              lower-case   counterparts   (for   example,   `glob',  `noglob',
4465              `NO_GLOB' are all completed).  Any arguments are  propagated  to
4466              the compadd builtin.
4467
4468       _options_set and _options_unset
4469              These  functions  complete  only  set or unset options, with the
4470              same matching specification used in the _options function.
4471
4472              Note that you need to uncomment a few lines  in  the  _main_com‐
4473              plete  function for these functions to work properly.  The lines
4474              in question are used to store the option settings in effect  be‐
4475              fore  the  completion  widget locally sets the options it needs.
4476              Hence these functions are not generally used by  the  completion
4477              system.
4478
4479       _parameters
4480              This is used to complete the names of shell parameters.
4481
4482              The  option  `-g  pattern'  limits  the completion to parameters
4483              whose type matches the pattern.  The type of a parameter is that
4484              shown by `print ${(t)param}', hence judicious use of `*' in pat‐
4485              tern is probably necessary.
4486
4487              All other arguments are passed to the compadd builtin.
4488
4489       _path_files
4490              This function is used throughout the completion system  to  com‐
4491              plete  filenames.   It  allows completion of partial paths.  For
4492              example, the string `/u/i/s/sig' may be completed  to  `/usr/in‐
4493              clude/sys/signal.h'.
4494
4495              The options accepted by both _path_files and _files are:
4496
4497              -f     Complete all filenames.  This is the default.
4498
4499              -/     Specifies that only directories should be completed.
4500
4501              -g pattern
4502                     Specifies  that only files matching the pattern should be
4503                     completed.
4504
4505              -W paths
4506                     Specifies path prefixes that are to be prepended  to  the
4507                     string  from  the  command line to generate the filenames
4508                     but that should not be inserted as completions nor  shown
4509                     in  completion  listings.  Here, paths may be the name of
4510                     an array parameter, a literal list of paths  enclosed  in
4511                     parentheses or an absolute pathname.
4512
4513              -F ignored-files
4514                     This  behaves as for the corresponding option to the com‐
4515                     padd builtin.  It gives direct control over  which  file‐
4516                     names  should  be ignored.  If the option is not present,
4517                     the ignored-patterns style is used.
4518
4519              Both _path_files and _files also accept  the  following  options
4520              which are passed to compadd: `-J', `-V', `-1', `-2', `-n', `-X',
4521              `-M', `-P', `-S', `-q', `-r', and `-R'.
4522
4523              Finally, the _path_files function  uses the styles  expand,  am‐
4524              biguous,  special-dirs,  list-suffixes  and  file-sort described
4525              above.
4526
4527
4528       _pick_variant [ -b builtin-label ] [ -c command ] [ -r name ]
4529                     label=pattern ... label [ arg ... ]
4530              This function is used to resolve situations where a single  com‐
4531              mand  name  requires  more than one type of handling, either be‐
4532              cause it has more than one variant or because there  is  a  name
4533              clash between two different commands.
4534
4535              The  command to run is taken from the first element of the array
4536              words unless this is overridden by the option -c.  This  command
4537              is  run  and  its  output is compared with a series of patterns.
4538              Arguments to be passed to the command can be  specified  at  the
4539              end after all the other arguments.  The patterns to try in order
4540              are given by the arguments label=pattern; if the output of `com‐
4541              mand  arg  ...'  contains pattern, then label is selected as the
4542              label for the command variant.  If none of the  patterns  match,
4543              the final command label is selected and status 1 is returned.
4544
4545              If the `-b builtin-label' is given, the command is tested to see
4546              if it is provided as a shell builtin,  possibly  autoloaded;  if
4547              so,  the  label  builtin-label  is selected as the label for the
4548              variant.
4549
4550              If the `-r name' is given, the label picked is stored in the pa‐
4551              rameter named name.
4552
4553              The  results are also cached in the _cmd_variant associative ar‐
4554              ray indexed by the name of the command run.
4555
4556       _regex_arguments name spec ...
4557              This function generates a completion function name which matches
4558              the  specifications  specs,  a set of regular expressions as de‐
4559              scribed below.  After  running  _regex_arguments,  the  function
4560              name should be called as a normal completion function.  The pat‐
4561              tern to be matched is given by the contents of the  words  array
4562              up  to  the  current  cursor  position joined together with null
4563              characters; no quotation is applied.
4564
4565              The arguments are grouped as sets of alternatives  separated  by
4566              `|',  which  are  tried  one  after the other until one matches.
4567              Each alternative consists of a one or more specifications  which
4568              are  tried  left  to  right,  with  each  pattern  matched being
4569              stripped in turn from the command line being tested,  until  all
4570              of  the  group  succeeds or until one fails; in the latter case,
4571              the next alternative is tried.  This structure can  be  repeated
4572              to  arbitrary depth by using parentheses; matching proceeds from
4573              inside to outside.
4574
4575              A special procedure is applied if no test succeeds but  the  re‐
4576              maining command line string contains no null character (implying
4577              the remaining word is the one for which completions  are  to  be
4578              generated).   The completion target is restricted to the remain‐
4579              ing word and any actions for the corresponding patterns are exe‐
4580              cuted.   In this case, nothing is stripped from the command line
4581              string.  The order of evaluation of the actions  can  be  deter‐
4582              mined  by  the tag-order style; the various formats supported by
4583              _alternative can be used in action.  The descr is used for  set‐
4584              ting up the array parameter expl.
4585
4586              Specification  arguments  take  one of following forms, in which
4587              metacharacters such as `(', `)', `#' and `|' should be quoted.
4588
4589              /pattern/ [%lookahead%] [-guard] [:tag:descr:action]
4590                     This is a single primitive component.  The function tests
4591                     whether   the  combined  pattern  `(#b)((#B)pattern)look‐
4592                     ahead*' matches the command line string.  If so,  `guard'
4593                     is  evaluated and its return status is examined to deter‐
4594                     mine if the test has succeeded.  The pattern string  `[]'
4595                     is  guaranteed  never  to  match.   The  lookahead is not
4596                     stripped from the command line before the next pattern is
4597                     examined.
4598
4599                     The  argument  starting with : is used in the same manner
4600                     as an argument to _alternative.
4601
4602                     A component is used as follows: pattern is tested to  see
4603                     if  the component already exists on the command line.  If
4604                     it does, any following  specifications  are  examined  to
4605                     find  something  to  complete.  If a component is reached
4606                     but no such pattern exists yet on the command  line,  the
4607                     string  containing the action is used to generate matches
4608                     to insert at that point.
4609
4610              /pattern/+ [%lookahead%] [-guard] [:tag:descr:action]
4611                     This is similar to `/pattern/ ...' but the left  part  of
4612                     the command line string (i.e. the part already matched by
4613                     previous patterns) is also considered part of the comple‐
4614                     tion target.
4615
4616              /pattern/- [%lookahead%] [-guard] [:tag:descr:action]
4617                     This is similar to `/pattern/ ...' but the actions of the
4618                     current and previously matched patterns are ignored  even
4619                     if the following `pattern' matches the empty string.
4620
4621              ( spec )
4622                     Parentheses may be used to groups specs; note each paren‐
4623                     thesis is a single argument to _regex_arguments.
4624
4625              spec # This allows any number of repetitions of spec.
4626
4627              spec spec
4628                     The two specs are to be matched one after  the  other  as
4629                     described above.
4630
4631              spec | spec
4632                     Either of the two specs can be matched.
4633
4634              The  function  _regex_words  can be used as a helper function to
4635              generate matches for a set of alternative  words  possibly  with
4636              their own arguments as a command line argument.
4637
4638              Examples:
4639
4640                     _regex_arguments _tst /$'[^\0]#\0'/ \
4641                         /$'[^\0]#\0'/ :'compadd aaa'
4642
4643              This  generates  a  function _tst that completes aaa as its only
4644              argument.  The tag and description  for  the  action  have  been
4645              omitted for brevity (this works but is not recommended in normal
4646              use).  The first component matches the command  word,  which  is
4647              arbitrary; the second matches  any argument.  As the argument is
4648              also arbitrary, any following component would not depend on  aaa
4649              being present.
4650
4651                     _regex_arguments _tst /$'[^\0]#\0'/ \
4652                         /$'aaa\0'/ :'compadd aaa'
4653
4654              This  is  a  more  typical use; it is similar, but any following
4655              patterns would only match if aaa was present as the first  argu‐
4656              ment.
4657
4658                     _regex_arguments _tst /$'[^\0]#\0'/ \( \
4659                         /$'aaa\0'/ :'compadd aaa' \
4660                         /$'bbb\0'/ :'compadd bbb' \) \#
4661
4662              In  this  example, an indefinite number of command arguments may
4663              be completed.  Odd arguments are completed as aaa and even argu‐
4664              ments  as  bbb.   Completion fails unless the set of aaa and bbb
4665              arguments before the current one is matched correctly.
4666
4667                     _regex_arguments _tst /$'[^\0]#\0'/ \
4668                         \( /$'aaa\0'/ :'compadd aaa' \| \
4669                         /$'bbb\0'/ :'compadd bbb' \) \#
4670
4671              This is similar, but either aaa or bbb may be completed for  any
4672              argument.  In this case _regex_words could be used to generate a
4673              suitable expression for the arguments.
4674
4675       _regex_words tag description spec ...
4676              This  function  can  be  used  to  generate  arguments  for  the
4677              _regex_arguments  command  which  may  be  inserted at any point
4678              where a set of rules is expected.  The tag and description  give
4679              a  standard  tag  and description pertaining to the current con‐
4680              text.  Each spec contains two or three arguments separated by  a
4681              colon: note that there is no leading colon in this case.
4682
4683              Each  spec  gives one of a set of words that may be completed at
4684              this point, together with arguments.  It is thus roughly equiva‐
4685              lent  to the _arguments function when used in normal (non-regex)
4686              completion.
4687
4688              The part of the spec before the first colon is the  word  to  be
4689              completed.   This  may  contain a *; the entire word, before and
4690              after the * is completed, but only the text before the * is  re‐
4691              quired  for the context to be matched, so that further arguments
4692              may be completed after the abbreviated form.
4693
4694              The second part of spec is a description for the word being com‐
4695              pleted.
4696
4697              The  optional third part of the spec describes how words follow‐
4698              ing the one being completed are themselves to be completed.   It
4699              will be evaluated in order to avoid problems with quoting.  This
4700              means that typically it contains a reference to  an  array  con‐
4701              taining previously generated regex arguments.
4702
4703              The  option  -t term specifies a terminator for the word instead
4704              of the usual space.  This is handled as an auto-removable suffix
4705              in the manner of the option -s sep to _values.
4706
4707              The  result  of  the processing by _regex_words is placed in the
4708              array reply, which should be made local to the calling function.
4709              If the set of words and arguments may be matched repeatedly, a #
4710              should be appended to the generated array at that point.
4711
4712              For example:
4713
4714                     local -a reply
4715                     _regex_words mydb-commands 'mydb commands' \
4716                       'add:add an entry to mydb:$mydb_add_cmds' \
4717                       'show:show entries in mydb'
4718                     _regex_arguments _mydb "$reply[@]"
4719                     _mydb "$@"
4720
4721              This shows a completion function for a command mydb which  takes
4722              two  command  arguments, add and show.  show takes no arguments,
4723              while the arguments for add have already been prepared in an ar‐
4724              ray   mydb_add_cmds,  quite  possibly  by  a  previous  call  to
4725              _regex_words.
4726
4727       _requested [ -x ] [ -12VJ ] tag [ name descr [ command [ arg ... ] ]
4728              This function is called to decide whether a tag  already  regis‐
4729              tered  by  a call to _tags (see below) has been requested by the
4730              user and hence completion should be performed for  it.   It  re‐
4731              turns  status  zero  if the tag is requested and non-zero other‐
4732              wise.  The function is typically used as part  of  a  loop  over
4733              different tags as follows:
4734
4735                     _tags foo bar baz
4736                     while _tags; do
4737                       if _requested foo; then
4738                         ... # perform completion for foo
4739                       fi
4740                       ... # test the tags bar and baz in the same way
4741                       ... # exit loop if matches were generated
4742                     done
4743
4744              Note  that  the  test  for whether matches were generated is not
4745              performed until the end of the _tags loop.  This is so that  the
4746              user  can set the tag-order style to specify a set of tags to be
4747              completed at the same time.
4748
4749              If name and descr are given, _requested calls  the  _description
4750              function  with  these arguments together with the options passed
4751              to _requested.
4752
4753              If command is given, the _all_labels function will be called im‐
4754              mediately  with  the same arguments.  In simple cases this makes
4755              it possible to perform the test for the tag and the matching  in
4756              one go.  For example:
4757
4758                     local expl ret=1
4759                     _tags foo bar baz
4760                     while _tags; do
4761                       _requested foo expl 'description' \
4762                           compadd foobar foobaz && ret=0
4763                       ...
4764                       (( ret )) || break
4765                     done
4766
4767              If  the command is not compadd, it must nevertheless be prepared
4768              to handle the same options.
4769
4770       _retrieve_cache cache_identifier
4771              This function retrieves completion  information  from  the  file
4772              given  by  cache_identifier,  stored in a directory specified by
4773              the cache-path style which defaults to ~/.zcompcache.   The  re‐
4774              turn  status  is zero if retrieval was successful.  It will only
4775              attempt retrieval if the use-cache style is set, so you can call
4776              this  function without worrying about whether the user wanted to
4777              use the caching layer.
4778
4779              See _store_cache below for more details.
4780
4781       _sep_parts
4782              This function is passed alternating arrays and separators as ar‐
4783              guments.  The arrays specify completions for parts of strings to
4784              be separated by the separators.  The arrays may be the names  of
4785              array  parameters or a quoted list of words in parentheses.  For
4786              example, with the array `hosts=(ftp news)' the call  `_sep_parts
4787              '(foo  bar)' @ hosts' will complete the string  `f' to `foo' and
4788              the string `b@n' to `bar@news'.
4789
4790              This function accepts the  compadd  options  `-V',  `-J',  `-1',
4791              `-2',  `-n',  `-X',  `-M',  `-P', `-S', `-r', `-R', and `-q' and
4792              passes them on to the compadd builtin used to add the matches.
4793
4794       _sequence [ -s sep ] [ -n max ] [ -d ] function [ - ] ...
4795              This function is a wrapper to  other  functions  for  completing
4796              items in a separated list. The same function is used to complete
4797              each item in the list. The separator is specified  with  the  -s
4798              option.  If  -s is omitted it will use `,'. Duplicate values are
4799              not matched unless -d is specified. If there is a fixed or maxi‐
4800              mum  number of items in the list, this can be specified with the
4801              -n option.
4802
4803              Common compadd options are passed on to the function. It is pos‐
4804              sible to use compadd directly with _sequence, though _values may
4805              be more appropriate in this situation.
4806
4807       _setup tag [ group ]
4808              This function sets up the special parameters used by the comple‐
4809              tion  system  appropriately for the tag given as the first argu‐
4810              ment.    It   uses   the   styles   list-colors,    list-packed,
4811              list-rows-first, last-prompt, accept-exact, menu and force-list.
4812
4813              The  optional  group supplies the name of the group in which the
4814              matches will be placed.  If it is not given, the tag is used  as
4815              the group name.
4816
4817              This  function  is  called  automatically  from _description and
4818              hence is not normally called explicitly.
4819
4820       _store_cache cache_identifier param ...
4821              This function, together with _retrieve_cache and _cache_invalid,
4822              implements  a  caching layer which can be used in any completion
4823              function.  Data obtained by costly operations are stored in  pa‐
4824              rameters;  this  function then dumps the values of those parame‐
4825              ters to a file.  The data can then  be  retrieved  quickly  from
4826              that  file  via  _retrieve_cache, even in different instances of
4827              the shell.
4828
4829              The cache_identifier specifies the file which the data should be
4830              dumped  to.   The file is stored in a directory specified by the
4831              cache-path style which defaults to ~/.zcompcache.  The remaining
4832              params arguments are the parameters to dump to the file.
4833
4834              The  return status is zero if storage was successful.  The func‐
4835              tion will only attempt storage if the use-cache style is set, so
4836              you  can  call  this function without worrying about whether the
4837              user wanted to use the caching layer.
4838
4839              The completion function may avoid calling  _retrieve_cache  when
4840              it  already  has  the  completion  data available as parameters.
4841              However, in that case it should  call  _cache_invalid  to  check
4842              whether  the  data  in the parameters and in the cache are still
4843              valid.
4844
4845              See the _perl_modules completion function for a  simple  example
4846              of the usage of the caching layer.
4847
4848       _tags [ [ -C name ] tag ... ]
4849              If  called  with  arguments,  these are taken to be the names of
4850              tags valid for completions in the current context.   These  tags
4851              are stored internally and sorted by using the tag-order style.
4852
4853              Next, _tags is called repeatedly without arguments from the same
4854              completion function.  This successively selects the first,  sec‐
4855              ond,  etc. set of tags requested by the user.  The return status
4856              is zero if at least one of the tags is  requested  and  non-zero
4857              otherwise.  To test if a particular tag is to be tried, the _re‐
4858              quested function should be called (see above).
4859
4860              If `-C name' is given, name is temporarily stored in  the  argu‐
4861              ment  field (the fifth) of the context in the curcontext parame‐
4862              ter during the call to _tags; the field  is  restored  on  exit.
4863              This  allows _tags to use a more specific context without having
4864              to change and reset the curcontext parameter (which has the same
4865              effect).
4866
4867       _tilde_files
4868              Like  _files,  but resolve leading tildes according to the rules
4869              of filename expansion, so the suggested completions don't  start
4870              with a `~' even if the filename on the command-line does.
4871
4872       _values [ -O name ] [ -s sep ] [ -S sep ] [ -wC ] desc spec ...
4873              This  is  used to complete arbitrary keywords (values) and their
4874              arguments, or lists of such combinations.
4875
4876              If the first argument is the option `-O name', it will  be  used
4877              in  the same way as by the _arguments function.  In other words,
4878              the elements of the name array will be passed  to  compadd  when
4879              executing an action.
4880
4881              If the first argument (or the first argument after `-O name') is
4882              `-s', the next argument is used as the character that  separates
4883              multiple  values.   This  character is automatically added after
4884              each value in an auto-removable fashion (see below); all  values
4885              completed by `_values -s' appear in the same word on the command
4886              line, unlike completion using _arguments.  If this option is not
4887              present, only a single value will be completed per word.
4888
4889              Normally,  _values  will  only use the current word to determine
4890              which values are already present on the command line  and  hence
4891              are not to be completed again.  If the -w option is given, other
4892              arguments are examined as well.
4893
4894              The first non-option argument, desc, is  used  as  a  string  to
4895              print as a description before listing the values.
4896
4897              All other arguments describe the possible values and their argu‐
4898              ments in the same format used for the description of options  by
4899              the  _arguments  function (see above).  The only differences are
4900              that no minus or plus sign is required at the beginning,  values
4901              can  have  only  one argument, and the forms of action beginning
4902              with an equal sign are not supported.
4903
4904              The character separating a value from its argument  can  be  set
4905              using  the  option -S (like -s, followed by the character to use
4906              as the separator in the next argument).  By default  the  equals
4907              sign will be used as the separator between values and arguments.
4908
4909              Example:
4910
4911                     _values -s , 'description' \
4912                             '*foo[bar]' \
4913                             '(two)*one[number]:first count:' \
4914                             'two[another number]::second count:(1 2 3)'
4915
4916              This  describes  three possible values: `foo', `one', and `two'.
4917              The first is described as `bar', takes no argument and  may  ap‐
4918              pear  more  than once.  The second is described as `number', may
4919              appear more than once, and  takes  one  mandatory  argument  de‐
4920              scribed as `first count'; no action is specified, so it will not
4921              be completed.  The `(two)' at the beginning  says  that  if  the
4922              value  `one'  is  on the line, the value `two' will no longer be
4923              considered a  possible  completion.   Finally,  the  last  value
4924              (`two')  is  described as `another number' and takes an optional
4925              argument described as `second count' for which  the  completions
4926              (to  appear  after  an  `=') are `1', `2', and `3'.  The _values
4927              function will complete lists of these values separated  by  com‐
4928              mas.
4929
4930              Like  _arguments, this function temporarily adds another context
4931              name component to the arguments element (the fifth) of the  cur‐
4932              rent context while executing the action.  Here this name is just
4933              the name of the value for which the argument is completed.
4934
4935              The style verbose is used to decide if the descriptions for  the
4936              values (but not those for the arguments) should be printed.
4937
4938              The  associative  array  val_args  is  used to report values and
4939              their arguments; this works similarly to the  opt_args  associa‐
4940              tive array used by _arguments.  Hence the function calling _val‐
4941              ues should declare  the  local  parameters  state,  state_descr,
4942              line, context and val_args:
4943
4944                     local context state state_descr line
4945                     typeset -A val_args
4946
4947              when using an action of the form `->string'.  With this function
4948              the context parameter will be set to the name of the value whose
4949              argument  is  to be completed.  Note that for _values, the state
4950              and state_descr are scalars rather than arrays.  Only  a  single
4951              matching state is returned.
4952
4953              Note  also  that _values normally adds the character used as the
4954              separator between values as an auto-removable suffix (similar to
4955              a  `/'  after a directory).  However, this is not possible for a
4956              `->string' action as the matches for the argument are  generated
4957              by  the calling function.  To get the usual behaviour, the call‐
4958              ing function can add the separator x as a suffix by passing  the
4959              options `-qS x' either directly or indirectly to compadd.
4960
4961              The option -C is treated in the same way as it is by _arguments.
4962              In that case the parameter curcontext should be made  local  in‐
4963              stead of context (as described above).
4964
4965       _wanted [ -x ] [ -C name ]  [ -12VJ ] tag name descr command [ arg ...]
4966              In  many  contexts,  completion can only generate one particular
4967              set of matches, usually corresponding to a single tag.  However,
4968              it  is  still  necessary  to  decide  whether  the user requires
4969              matches of this type.  This function is useful in such a case.
4970
4971              The arguments to _wanted are the same as  those  to  _requested,
4972              i.e.  arguments  to be passed to _description.  However, in this
4973              case the command is not optional;  all the processing  of  tags,
4974              including the loop over both tags and tag labels and the genera‐
4975              tion of matches, is carried out automatically by _wanted.
4976
4977              Hence to offer only one tag and immediately add the  correspond‐
4978              ing matches with the given description:
4979
4980                     local expl
4981                     _wanted tag expl 'description' \
4982                         compadd -- match1 match2...
4983
4984              See  also the use of _wanted in the example function in the sub‐
4985              section `Dynamic named directories' in zshexpn(1).
4986
4987              Note that, as for _requested, the command must be able to accept
4988              options to be passed down to compadd.
4989
4990              Like  _tags  this function supports the -C option to give a dif‐
4991              ferent name for the argument context field.  The -x  option  has
4992              the same meaning as for _description.
4993
4994       _widgets [ -g pattern ]
4995              This  function  completes  names of zle widgets (see the section
4996              `Widgets' in zshzle(1)).  The pattern, if  present,  is  matched
4997              against  values of the $widgets special parameter, documented in
4998              the section `The zsh/zleparameter Module' in zshmodules(1).
4999

COMPLETION SYSTEM VARIABLES

5001       There are some standard variables, initialised  by  the  _main_complete
5002       function and then used from other functions.
5003
5004       The standard variables are:
5005
5006       _comp_caller_options
5007              The  completion  system  uses setopt to set a number of options.
5008              This allows functions to be written without concern for compati‐
5009              bility with every possible combination of user options. However,
5010              sometimes completion needs to know what the user's option  pref‐
5011              erences  are.  These are saved in the _comp_caller_options asso‐
5012              ciative array. Option names, spelled in lowercase without under‐
5013              scores,  are  mapped  to  one  or  other of the strings `on' and
5014              `off'.
5015
5016       _comp_priv_prefix
5017              Completion functions such as _sudo can set the _comp_priv_prefix
5018              array to a command prefix that may then be used by _call_program
5019              to match  the  privileges  when  calling  programs  to  generate
5020              matches.
5021
5022       Two  more features are offered by the _main_complete function.  The ar‐
5023       rays compprefuncs and comppostfuncs may contain names of functions that
5024       are to be called immediately before or after completion has been tried.
5025       A function will only be called once unless it explicitly reinserts  it‐
5026       self into the array.
5027

COMPLETION DIRECTORIES

5029       In  the  source distribution, the files are contained in various subdi‐
5030       rectories of the Completion directory.  They may have been installed in
5031       the same structure, or into one single function directory.  The follow‐
5032       ing is a description of the  files  found  in  the  original  directory
5033       structure.   If  you  wish to alter an installed file, you will need to
5034       copy it to some directory which appears earlier in your fpath than  the
5035       standard directory where it appears.
5036
5037       Base   The  core functions and special completion widgets automatically
5038              bound to keys.  You will certainly need most  of  these,  though
5039              will  probably  not need to alter them.  Many of these are docu‐
5040              mented above.
5041
5042       Zsh    Functions for completing arguments of shell builtin commands and
5043              utility  functions  for  this.   Some  of these are also used by
5044              functions from the Unix directory.
5045
5046       Unix   Functions for completing  arguments  of  external  commands  and
5047              suites  of  commands.   They may need modifying for your system,
5048              although in many cases some attempt is made to decide which ver‐
5049              sion  of  a command is present.  For example, completion for the
5050              mount command tries to determine the system it  is  running  on,
5051              while  completion for many other utilities try to decide whether
5052              the GNU version of the command is in use, and hence whether  the
5053              --help option is supported.
5054
5055       X, AIX, BSD, ...
5056              Completion  and  utility function for commands available only on
5057              some systems.  These are not arranged  hierarchically,  so,  for
5058              example, both the Linux and Debian directories, as well as the X
5059              directory, may be useful on your system.
5060
5061
5062
5063zsh 5.9                          May 14, 2022                    ZSHCOMPSYS(1)
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