Provided by: zsh_4.3.4-24ubuntu1_i386 bug

NAME

       zshcompwid - zsh completion widgets

DESCRIPTION

       The shell’s programmable completion mechanism can be manipulated in two
       ways; here the low-level features supporting the newer,  function-based
       mechanism  are  defined.   A  complete  set of shell functions based on
       these features  is  described  in  zshcompsys(1),  and  users  with  no
       interest  in  adding to that system (or, potentially, writing their own
       -- see dictionary entry for ‘hubris’) should skip the current  section.
       The  older  system based on the compctl builtin command is described in
       zshcompctl(1).

       Completion widgets are defined by the -C  option  to  the  zle  builtin
       command provided by the zsh/zle module (see zshzle(1)). For example,

              zle -C complete expand-or-complete completer

       defines  a widget named ‘complete’.  The second argument is the name of
       any of the builtin  widgets  that  handle  completions:  complete-word,
       expand-or-complete,      expand-or-complete-prefix,      menu-complete,
       menu-expand-or-complete,   reverse-menu-complete,   list-choices,    or
       delete-char-or-list.  Note that this will still work even if the widget
       in question has been re-bound.

       When this newly defined widget is bound to  a  key  using  the  bindkey
       builtin  command  defined in the zsh/zle module (see zshzle(1)), typing
       that key will call the shell function  ‘completer’.  This  function  is
       responsible  for  generating  the  possible  matches using the builtins
       described below.  As with other ZLE widgets,  the  function  is  called
       with its standard input closed.

       Once the function returns, the completion code takes over control again
       and treats the matches in the same  manner  as  the  specified  builtin
       widget, in this case expand-or-complete.

SPECIAL PARAMETERS

       Inside  completion  widgets,  and  any functions called from them, some
       parameters have special meaning; outside these functions they  are  not
       special  to  the  shell  in any way.  These parameters are used to pass
       information between the completion code and the completion widget. Some
       of  the  builtin  commands  and  the  condition codes use or change the
       current values of these parameters.  Any existing values will be hidden
       during  execution  of  completion  widgets;  except  for compstate, the
       parameters are reset on each function exit (including  nested  function
       calls  from  within  the completion widget) to the values they had when
       the function was entered.

       CURRENT
              This is the number of the current word, i.e. the word the cursor
              is  currently  on  in  the words array.  Note that this value is
              only correct if the ksharrays option is not set.

       IPREFIX
              Initially this will be set to the empty string.  This  parameter
              functions  like  PREFIX; it contains a string which precedes the
              one in PREFIX and is not considered part of the list of matches.
              Typically,  a string is transferred from the beginning of PREFIX
              to the end of IPREFIX, for example:

                     IPREFIX=${PREFIX%%\=*}=
                     PREFIX=${PREFIX#*=}

              causes the part of the prefix up  to  and  including  the  first
              equal  sign not to be treated as part of a matched string.  This
              can be done automatically by the compset builtin, see below.

       ISUFFIX
              As IPREFIX, but for a suffix that should not be considered  part
              of  the matches; note that the ISUFFIX string follows the SUFFIX
              string.

       PREFIX Initially this will be set to the part of the current word  from
              the  beginning  of the word up to the position of the cursor; it
              may be altered to give a common prefix for all matches.

       QIPREFIX
              This parameter is read-only and contains the quoted string up to
              the  word  being  completed.  E.g.  when completing ‘"foo’, this
              parameter contains the double quote. If the -q option of compset
              is used (see below), and the original string was ‘"foo bar’ with
              the cursor on the ‘bar’, this parameter contains ‘"foo ’.

       QISUFFIX
              Like QIPREFIX, but containing the suffix.

       SUFFIX Initially this will be set to the part of the current word  from
              the  cursor  position  to  the  end; it may be altered to give a
              common suffix for all matches.   It  is  most  useful  when  the
              option  COMPLETE_IN_WORD  is set, as otherwise the whole word on
              the command line is treated as a prefix.

       compstate
              This is an associative array with various keys and  values  that
              the  completion  code  uses  to  exchange  information  with the
              completion widget.  The keys are:

              all_quotes
                     The -q option of the compset builtin command (see  below)
                     allows  a quoted string to be broken into separate words;
                     if the cursor is on one of those words, that word will be
                     completed,  possibly  invoking  ‘compset -q’ recursively.
                     With this key it is possible to test the types of  quoted
                     strings  which  are  currently  broken into parts in this
                     fashion.  Its  value  contains  one  character  for  each
                     quoting  level.   The  characters are a single quote or a
                     double quote for strings quoted with these characters,  a
                     dollars  sign  for  strings  quoted  with  $...’  and  a
                     backslash  for  strings  not  starting   with   a   quote
                     character.   The  first  character  in  the  value always
                     corresponds to the innermost quoting level.

              context
                     This will be set by the completion code  to  the  overall
                     context in which completion is attempted. Possible values
                     are:

                     array_value
                             when completing inside  the  value  of  an  array
                             parameter  assignment;  in  this  case  the words
                             array contains the words inside the  parentheses.

                     brace_parameter
                             when  completing  the  name  of  a parameter in a
                             parameter expansion beginning with ${.

                     assign_parameter
                             when completing the name  of  a  parameter  in  a
                             parameter assignment.

                     command
                             when  completing  for a normal command (either in
                             command  position  or  for  an  argument  of  the
                             command).

                     condition
                             when  completing  inside  a ‘[[...]]’ conditional
                             expression; in this case the words array contains
                             only the words inside the conditional expression.

                      math   when completing  in  a  mathematical  environment
                             such as a ‘((...))’ construct.

                     parameter
                             when  completing  the  name  of  a parameter in a
                             parameter expansion beginning with $ but not  ${.

                     redirect
                             when completing after a redirection operator.

                     subscript
                             when completing inside a parameter subscript.

                      value  when   completing   the   value  of  a  parameter
                             assignment.

              exact  Controls the behaviour when the REC_EXACT option is  set.
                     It  will  be  set  to  accept  if an exact match would be
                     accepted, and will be unset otherwise.

                     If it was set when at least one match equal to the string
                     on the line was generated, the match is accepted.

              exact_string
                     The  string of an exact match if one was found, otherwise
                     unset.

              ignored
                     The number  of  words  that  were  ignored  because  they
                     matched  one  of the patterns given with the -F option to
                     the compadd builtin command.

              insert This controls the manner in which  a  match  is  inserted
                     into  the command line.  On entry to the widget function,
                     if it is unset the command line is not to be changed;  if
                     set  to  unambiguous, any prefix common to all matches is
                     to be  inserted;  if  set  to  automenu-unambiguous,  the
                     common  prefix  is to be inserted and the next invocation
                     of the completion code may start menu completion (due  to
                     the  AUTO_MENU  option  being  set);  if  set  to menu or
                     automenu menu completion will be started for the  matches
                     currently  generated (in the latter case this will happen
                     because the AUTO_MENU is set). The value may also contain
                     the  string ‘tab’ when the completion code would normally
                     not  really  do  completion,  but  only  insert  the  TAB
                     character.

                     On  exit  it may be set to any of the values above (where
                     setting it to the empty string is the same  as  unsetting
                     it), or to a number, in which case the match whose number
                     is  given  will  be  inserted  into  the  command   line.
                     Negative numbers count backward from the last match (with
                     ‘-1’ selecting the last match)  and  out-of-range  values
                     are  wrapped  around, so that a value of zero selects the
                     last match and a value one more than the maximum  selects
                     the  first. Unless the value of this key ends in a space,
                     the match is inserted  as  in  a  menu  completion,  i.e.
                     without automatically appending a space.

                     Both menu and automenu may also specify the the number of
                     the match to insert, given after a colon.   For  example,
                     ‘menu:2’  says  to  start menu completion, beginning with
                     the second match.

                     Note that a value containing the  substring  ‘tab’  makes
                     the  matches  generated  be  ignored  and only the TAB be
                     inserted.

                     Finally, it may also be  set  to  all,  which  makes  all
                     matches generated be inserted into the line.

              insert_positions
                     When  the completion system inserts an unambiguous string
                     into  the  line,  there  may  be  multiple  places  where
                     characters  are  missing  or where the character inserted
                     differs from at least one match.  The value of  this  key
                     contains  a  colon separated list of all these positions,
                     as indexes into the command line.

              last_prompt
                     If this is set to a  non-empty  string  for  every  match
                     added,  the  completion code will move the cursor back to
                     the previous prompt after the  list  of  completions  has
                     been displayed.  Initially this is set or unset according
                     to the ALWAYS_LAST_PROMPT option.

              list   This controls whether or how the list of matches will  be
                     displayed.   If  it  is unset or empty they will never be
                     listed; if its value begins with list, they  will  always
                     be  listed; if it begins with autolist or ambiguous, they
                     will be  listed  when  the  AUTO_LIST  or  LIST_AMBIGUOUS
                     options respectively would normally cause them to be.

                     If  the  substring force appears in the value, this makes
                     the list be shown  even  if  there  is  only  one  match.
                     Normally,  the  list  would be shown only if there are at
                     least two matches.

                     The  value  contains  the   substring   packed   if   the
                     LIST_PACKED option is set. If this substring is given for
                     all matches added to a group, this group  will  show  the
                     LIST_PACKED   behavior.   The   same   is  done  for  the
                     LIST_ROWS_FIRST option with the substring rows.

                     Finally, if the value contains the  string  explanations,
                     only  the explanation strings, if any, will be listed and
                     if it contains messages, only the  messages  (added  with
                     the -x option of compadd) will be listed.  If it contains
                     both explanations and messages both kinds of  explanation
                     strings  will be listed.  It will be set appropriately on
                     entry to a completion widget and may be changed there.

              list_lines
                     This gives the number of lines that are needed to display
                     the full list of completions.  Note that to calculate the
                     total number of lines to display  you  need  to  add  the
                     number  of  lines  needed  for  the  command line to this
                     value, this is available as the value of the  BUFFERLINES
                     special parameter.

              list_max
                     Initially  this  is  set  to  the  value  of  the LISTMAX
                     parameter.  It may be set to any other  value;  when  the
                     widget  exits  this value will be used in the same way as
                     the value of LISTMAX.

              nmatches
                     The number of  matches  generated  and  accepted  by  the
                     completion code so far.

              old_insert
                     On  entry to the widget this will be set to the number of
                     the match of an old list of completions that is currently
                     inserted  into  the  command  line.  If no match has been
                     inserted, this is unset.

                     As with old_list, the value of this key will only be used
                     if  it is the string keep. If it was set to this value by
                     the widget and there was an old match inserted  into  the
                     command line, this match will be kept and if the value of
                     the insert key specifies that  another  match  should  be
                     inserted, this will be inserted after the old one.

              old_list
                     This  is  set  to  yes  if there is still a valid list of
                     completions from a previous completion at  the  time  the
                     widget  is invoked.  This will usually be the case if and
                     only if the previous editing operation was  a  completion
                     widget  or  one  of the builtin completion functions.  If
                     there is a valid list and it is also currently  shown  on
                     the screen, the value of this key is shown.

                     After the widget has exited the value of this key is only
                     used if it was set to keep.  In this case the  completion
                     code  will  continue to use this old list.  If the widget
                     generated new matches, they will not be used.

              parameter
                     The name of the parameter when completing in a  subscript
                     or in the value of a parameter assignment.

              pattern_insert
                     Normally  this  is set to menu, which specifies that menu
                     completion will be used whenever a  set  of  matches  was
                     generated  using  pattern  matching.  If it is set to any
                     other non-empty string by the user and menu completion is
                     not  selected  by  other  option  settings, the code will
                     instead  insert  any  common  prefix  for  the  generated
                     matches as with normal completion.

              pattern_match
                     Locally controls the behaviour given by the GLOB_COMPLETE
                     option.  Initially it is set to ‘*’ if and  only  if  the
                     option  is set.  The completion widget may set it to this
                     value, to an empty string (which has the same  effect  as
                     unsetting  it),  or to any other non-empty string.  If it
                     is non-empty, unquoted metacharacters on the command line
                     will   be  treated  as  patterns;  if  it  is  ‘*’,  then
                     additionally a wildcard ‘*’  is  assumed  at  the  cursor
                     position; if it is empty or unset, metacharacters will be
                     treated literally.

                     Note that the matcher specifications given to the compadd
                     builtin  command  are  not  used  if  this  is  set  to a
                     non-empty string.

              quote  When  completing  inside  quotes,   this   contains   the
                     quotation character (i.e. either a single quote, a double
                     quote, or a backtick).  Otherwise it is unset.

              quoting
                     When completing inside single quotes, this is set to  the
                     string  single;  inside double quotes, the string double;
                     inside backticks, the string backtick.  Otherwise  it  is
                     unset.

              redirect
                     The redirection operator when completing in a redirection
                     position, i.e. one of <, >, etc.

              restore
                     This is set to auto before a function is  entered,  which
                     forces  the  special  parameters  mentioned above (words,
                     CURRENT, PREFIX, IPREFIX,  SUFFIX,  and  ISUFFIX)  to  be
                     restored  to  their  previous  values  when  the function
                     exits.   If a function unsets it or sets it to any  other
                     string, they will not be restored.

              to_end Specifies  the  occasions on which the cursor is moved to
                     the end of a string when a match is inserted.   On  entry
                     to  a  widget  function,  it  may  be single if this will
                     happen when a single unambiguous match  was  inserted  or
                     match if it will happen any time a match is inserted (for
                     example, by menu completion; this is  likely  to  be  the
                     effect of the ALWAYS_TO_END option).

                     On  exit,  it may be set to single as above.  It may also
                     be set to always, or to the empty  string  or  unset;  in
                     those  cases  the  cursor will be moved to the end of the
                     string always or never respectively.  Any other string is
                     treated as match.

              unambiguous
                     This  key  is  read-only  and  will  always be set to the
                     common  (unambiguous)  prefix  the  completion  code  has
                     generated for all matches added so far.

              unambiguous_cursor
                     This  gives the position the cursor would be placed at if
                     the common prefix in the unambiguous key  were  inserted,
                     relative  to  the  value of that key. The cursor would be
                     placed before the character whose index is given by  this
                     key.

              unambiguous_positions
                     This  contains  all  positions  where  characters  in the
                     unambiguous string are missing  or  where  the  character
                     inserted  differs  from at least one of the matches.  The
                     positions are given as indexes into the string  given  by
                     the value of the unambiguous key.

              vared  If  completion  is  called while editing a line using the
                     vared builtin, the value of this key is set to  the  name
                     of the parameter given as an argument to vared.  This key
                     is only set while a vared command is active.

       words  This array contains  the  words  present  on  the  command  line
              currently being edited.

BUILTIN COMMANDS

       compadd [ -akqQfenUld12C ] [ -F array ]
       [ -P prefix ] [ -S suffix ]
       [ -p hidden-prefix ] [ -s hidden-suffix ]
       [ -i ignored-prefix ] [ -I ignored-suffix ]
       [ -W file-prefix ] [ -d array ]
       [ -J name ] [ -V name ] [ -X explanation ] [ -x message ]
       [ -r remove-chars ] [ -R remove-func ]
       [ -D array ] [ -O array ] [ -A array ]
       [ -E number ]
       [ -M match-spec ] [ -- ] [ words ... ]

              This  builtin  command  can  be used to add matches directly and
              control all the information the completion code stores with each
              possible  match. The return status is zero if at least one match
              was added and non-zero if no matches were added.

              The completion code breaks the string  to  complete  into  seven
              fields in the order:

                     <ipre><apre><hpre><word><hsuf><asuf><isuf>

              The  first  field  is  an  ignored prefix taken from the command
              line, the contents of the  IPREFIX  parameter  plus  the  string
              given  with  the  -i option. With the -U option, only the string
              from the -i option is used. The  field  <apre>  is  an  optional
              prefix  string  given with the -P option.  The <hpre> field is a
              string that is considered part of the match but that should  not
              be shown when listing completions, given with the -p option; for
              example, functions that do filename generation might  specify  a
              common  path  prefix  this way.  <word> is the part of the match
              that should appear in the list of completions, i.e. one  of  the
              words given at the end of the compadd command line. The suffixes
              <hsuf>, <asuf> and <isuf> correspond  to  the  prefixes  <hpre>,
              <apre>  and  <ipre>  and are given by the options -s, -S and -I,
              respectively.

              The supported flags are:

              -P prefix
                     This gives a string  to  be  inserted  before  the  given
                     words.  The string given is not considered as part of the
                     match and any shell metacharacters  in  it  will  not  be
                     quoted when the string is inserted.

              -S suffix
                     Like  -P,  but  gives  a  string to be inserted after the
                     match.

              -p hidden-prefix
                     This gives a string that  should  be  inserted  into  the
                     command  line before the match but that should not appear
                     in the list of matches. Unless the -U  option  is  given,
                     this  string must be matched as part of the string on the
                     command line.

              -s hidden-suffix
                     Like ‘-p’, but gives a string to insert after the  match.

              -i ignored-prefix
                     This  gives a string to insert into the command line just
                     before any string given with the  ‘-P’  option.   Without
                     ‘-P’  the string is inserted before the string given with
                     ‘-p’ or directly before the match.

              -I ignored-suffix
                     Like -i, but gives an ignored suffix.

              -a     With this flag the words are taken as names of arrays and
                     the  possible  matches  are  their  values.  If only some
                     elements of the arrays are needed,  the  words  may  also
                     contain subscripts, as in ‘foo[2,-1]’.

              -k     With   this   flag  the  words  are  taken  as  names  of
                     associative arrays and the  possible  matches  are  their
                     keys.   As for -a, the words may also contain subscripts,
                     as in ‘foo[(R)*bar*]’.

              -d array
                     This adds per-match display  strings.  The  array  should
                     contain  one  element per word given. The completion code
                     will then display the first element instead of the  first
                     word, and so on. The array may be given as the name of an
                     array parameter or directly as a space-separated list  of
                     words in parentheses.

                     If  there  are  fewer  display  strings  than  words, the
                     leftover words will be displayed unchanged and  if  there
                     are more display strings than words, the leftover display
                     strings will be silently ignored.

              -l     This option only has an effect if used together with  the
                     -d option. If it is given, the display strings are listed
                     one per line, not arrayed in columns.

              -o     This option only has an effect if used together with  the
                     -d  option.   If  it is given, the order of the output is
                     determined  by  the  match  strings;   otherwise  it   is
                     determined by the display strings (i.e. the strings given
                     by the -d option).

              -J name
                     Gives the name of the group of matches the  words  should
                     be stored in.

              -V name
                     Like  -J  but  naming  a  unsorted  group. These are in a
                     different name space than  groups  created  with  the  -J
                     flag.

              -1     If   given  together  with  the  -V  option,  makes  only
                     consecutive  duplicates  in  the  group  be  removed.  If
                     combined  with the -J option, this has no visible effect.
                     Note that groups  with  and  without  this  flag  are  in
                     different name spaces.

              -2     If  given  together  with  the -J or -V option, makes all
                     duplicates be kept. Again, groups with and  without  this
                     flag are in different name spaces.

              -X explanation
                     The  explanation  string will be printed with the list of
                     matches, above the group currently selected.

              -x message
                     Like -X, but the message will be printed  even  if  there
                     are no matches in the group.

              -q     The suffix given with -S will be automatically removed if
                     the next character typed is a blank or  does  not  insert
                     anything, or if the suffix consists of only one character
                     and the next character typed is the same character.

              -r remove-chars
                     This is a more versatile form  of  the  -q  option.   The
                     suffix  given  with  -S  or the slash automatically added
                     after  completing  directories  will   be   automatically
                     removed  if  the  next character typed inserts one of the
                     characters given in the  remove-chars.   This  string  is
                     parsed   as   a  characters  class  and  understands  the
                     backslash sequences  used  by  the  print  command.   For
                     example,  ‘-r  "a-z\t"’  removes  the  suffix if the next
                     character typed inserts a lowercase character or  a  TAB,
                     and  ‘-r "^0-9"’ removes the suffix if the next character
                     typed inserts anything but a digit. One  extra  backslash
                     sequence  is  understood  in this string: ‘\-’ stands for
                     all characters that insert nothing. Thus ‘-S "="  -q’  is
                     the same as ‘-S "=" -r "= \t\n\-"’.

                     This  option may also be used without the -S option; then
                     any automatically added space will be removed when one of
                     the characters in the list is typed.

              -R remove-func
                     This  is another form of the -r option. When a suffix has
                     been inserted and the completion accepted,  the  function
                     remove-func  will  be  called  after  the  next character
                     typed.  It is passed the  length  of  the  suffix  as  an
                     argument  and can use the special parameters available in
                     ordinary (non-completion) zle widgets (see zshzle(1))  to
                     analyse and modify the command line.

              -f     If  this  flag  is  given,  all of the matches built from
                     words are marked as being the names of files.   They  are
                     not required to be actual filenames, but if they are, and
                     the option LIST_TYPES is set, the  characters  describing
                     the  types  of  the files in the completion lists will be
                     shown. This also forces a slash to be added when the name
                     of a directory is completed.

              -e     This  flag  can  be used to tell the completion code that
                     the matches added are parameter  names  for  a  parameter
                     expansion.   This  will  make  the  AUTO_PARAM_SLASH  and
                     AUTO_PARAM_KEYS options be used for the matches.

              -W file-prefix
                     This string is a pathname that will be prepended to  each
                     of  the  matches  formed by the given words together with
                     any prefix specified by the -p option to form a  complete
                     filename  for  testing.   Hence  it  is  only  useful  if
                     combined  with  the  -f  flag,  as  the  tests  will  not
                     otherwise be performed.

              -F array
                     Specifies  an  array  containing patterns. Words matching
                     one of these patterns are ignored, i.e. not considered to
                     be possible matches.

                     The array may be the name of an array parameter or a list
                     of literal patterns enclosed in parentheses  and  quoted,
                     as  in  ‘-F  "(*?.o  *?.h)"’.  If the name of an array is
                     given, the  elements  of  the  array  are  taken  as  the
                     patterns.

              -Q     This  flag instructs the completion code not to quote any
                     metacharacters in the words when inserting them into  the
                     command line.

              -M match-spec
                     This  gives local match specifications as described below
                     in the section ‘Matching Control’.  This  option  may  be
                     given  more than once. In this case all match-specs given
                     are concatenated with spaces between  them  to  form  the
                     specification string to use.  Note that they will only be
                     used if the -U option is not given.

              -n     Specifies that the words added are to be used as possible
                     matches, but are not to appear in the completion listing.

              -U     If this flag is given, all words given will  be  accepted
                     and  no  matching  will  be  done by the completion code.
                     Normally this is used in functions that do  the  matching
                     themselves.

              -O array
                     If  this  option is given, the words are not added to the
                     set of possible completions.  Instead, matching  is  done
                     as  usual  and  all  of the words given as arguments that
                     match the string on the command line will  be  stored  in
                     the array parameter whose name is given as array.

              -A array
                     As  the  -O  option,  except that instead of those of the
                     words which match being  stored  in  array,  the  strings
                     generated  internally  by the completion code are stored.
                     For  example,  with  a  matching  specification  of   ‘-M
                     "L:|no="’,  the  string ‘nof’ on the command line and the
                     string ‘foo’ as one of the words, this option stores  the
                     string ‘nofoo’ in the array, whereas the -O option stores
                     the ‘foo’ originally given.

              -D array
                     As with -O, the  words  are  not  added  to  the  set  of
                     possible completions.  Instead, the completion code tests
                     whether each word in turn matches what is  on  the  line.
                     If  the n’th word does not match, the n’th element of the
                     array is removed.  Elements for which  the  corresponding
                     word is matched are retained.

              -C     This  option  adds  a  special match which expands to all
                     other matches when inserted into  the  line,  even  those
                     that  are added after this option is used.  Together with
                     the -d option it is possible to  specify  a  string  that
                     should  be  displayed in the list for this special match.
                     If no string is given, it  will  be  shown  as  a  string
                     containing  the  strings  that  would be inserted for the
                     other matches, truncated to the width of the screen.

              -E     This option adds number empty  matches  after  the  words
                     have  been  added.   An  empty  match  takes  up space in
                     completion listings but will never  be  inserted  in  the
                     line  and  can’t be selected with menu completion or menu
                     selection.  This  makes  empty  matches  only  useful  to
                     format completion lists and to make explanatory string be
                     shown in completion lists (since  empty  matches  can  be
                     given  display  strings with the -d option).  And because
                     all but one empty string would otherwise be removed, this
                     option implies the -V and -2 options (even if an explicit
                     -J option is given).

              -
              --     This flag  ends  the  list  of  flags  and  options.  All
                     arguments  after  it will be taken as the words to use as
                     matches even if they begin with hyphens.

              Except for the -M flag, if any of these flags is given more than
              once, the first one (and its argument) will be used.

       compset -p number
       compset -P [ number ] pattern
       compset -s number
       compset -S [ number ] pattern
       compset -n begin [ end ]
       compset -N beg-pat [ end-pat ]
       compset -q
              This  command simplifies modification of the special parameters,
              while its return status allows tests on them to be carried  out.

              The options are:

              -p number
                     If  the  contents  of the PREFIX parameter is longer than
                     number  characters,  the  first  number  characters   are
                     removed  from  it  and  appended  to  the contents of the
                     IPREFIX parameter.

              -P [ number ] pattern
                     If the value of the PREFIX parameter begins with anything
                     that  matches the pattern, the matched portion is removed
                     from PREFIX and appended to IPREFIX.

                     Without the optional number, the longest match is  taken,
                     but  if  number  is  given,  anything up to the number’th
                     match is moved.  If the number is negative, the number’th
                     longest  match  is moved. For example, if PREFIX contains
                     the string ‘a=b=c’, then compset -P*\=’ will  move  the
                     string  ‘a=b=’ into the IPREFIX parameter, but compset -P
                     1*\=’ will move only the string ‘a=’.

              -s number
                     As -p, but transfer the last number characters  from  the
                     value of SUFFIX to the front of the value of ISUFFIX.

              -S [ number ] pattern
                     As  -P, but match the last portion of SUFFIX and transfer
                     the matched portion to the front of the value of ISUFFIX.

              -n begin [ end ]
                     If   the  current  word  position  as  specified  by  the
                     parameter CURRENT is greater  than  or  equal  to  begin,
                     anything  up  to  the  begin’th  word is removed from the
                     words array and the value of  the  parameter  CURRENT  is
                     decremented by begin.

                     If  the  optional  end is given, the modification is done
                     only if the current word position is also  less  than  or
                     equal  to  end. In this case, the words from position end
                     onwards are also removed from the words array.

                     Both begin and end may be  negative  to  count  backwards
                     from the last element of the words array.

              -N beg-pat [ end-pat ]
                     If  one of the elements of the words array before the one
                     at the index given by the value of the parameter  CURRENT
                     matches  the  pattern  beg-pat,  all  elements  up to and
                     including the matching one are  removed  from  the  words
                     array and the value of CURRENT is changed to point to the
                     same word in the changed array.

                     If the optional pattern end-pat is also given, and  there
                     is  an  element in the words array matching this pattern,
                     the parameters are modified only if  the  index  of  this
                     word  is  higher  than  the  one  given  by  the  CURRENT
                     parameter (so that the matching word has to be after  the
                     cursor).  In  this  case, the words starting with the one
                     matching end-pat are also removed from the  words  array.
                     If  words  contains no word matching end-pat, the testing
                     and modification is performed as if it were not given.

              -q     The word currently being completed  is  split  on  spaces
                     into  separate  words, respecting the usual shell quoting
                     conventions.  The resulting words are stored in the words
                     array,   and   CURRENT,  PREFIX,  SUFFIX,  QIPREFIX,  and
                     QISUFFIX are modified to reflect the word  part  that  is
                     completed.

              In  all  the  above  cases the return status is zero if the test
              succeeded  and  the  parameters  were  modified   and   non-zero
              otherwise. This allows one to use this builtin in tests such as:

                     if compset -P*\=; then ...

              This forces anything up to and including the last equal sign  to
              be ignored by the completion code.

       compcall [ -TD ]
              This  allows  the  use  of  completions defined with the compctl
              builtin from within completion widgets.   The  list  of  matches
              will  be  generated  as  if  one  of  the  non-widget completion
              function (complete-word, etc.)  had  been  called,  except  that
              only compctls given for specific commands are used. To force the
              code to try completions defined with the -T  option  of  compctl
              and/or  the default completion (whether defined by compctl -D or
              the builtin default) in the appropriate places, the -T and/or -D
              flags can be passed to compcall.

              The  return  status  can  be  used to test if a matching compctl
              definition was found. It is non-zero if a compctl was found  and
              zero otherwise.

              Note that this builtin is defined by the zsh/compctl module.

CONDITION CODES

       The  following  additional condition codes for use within the [[ ... ]]
       construct are available in  completion  widgets.   These  work  on  the
       special  parameters.   All  of these tests can also be performed by the
       compset builtin, but in the case of the condition codes the contents of
       the special parameters are not modified.

       -prefix [ number ] pattern
              true if the test for the -P option of compset would succeed.

       -suffix [ number ] pattern
              true if the test for the -S option of compset would succeed.

       -after beg-pat
              true  if  the  test of the -N option with only the beg-pat given
              would succeed.

       -between beg-pat end-pat
              true if the test for the -N  option  with  both  patterns  would
              succeed.

MATCHING CONTROL

       It  is  possible by use of the -M option of the compadd builtin command
       to specify how the characters in the string to be  completed  (referred
       to  here  as  the  command line) map onto the characters in the list of
       matches produced by the completion code (referred to here as the  trial
       completions). Note that this is not used if the command line contains a
       glob pattern and the GLOB_COMPLETE option is set or  the  pattern_match
       of the compstate special association is set to a non-empty string.

       The  match-spec  given  as  the argument to the -M option (see ‘Builtin
       Commands’  above)  consists  of  one  or  more  matching   descriptions
       separated  by  whitespace.   Each  description  consists  of  a  letter
       followed by a colon and then the patterns  describing  which  character
       sequences  on  the  line  match  which character sequences in the trial
       completion.  Any sequence of characters not  handled  in  this  fashion
       must match exactly, as usual.

       The  forms  of  match-spec understood are as follows. In each case, the
       form with an uppercase initial character  retains  the  string  already
       typed on the command line as the final result of completion, while with
       a lowercase initial character the string on the command line is changed
       into the corresponding part of the trial completion.

       m:lpat=tpat
       M:lpat=tpat
              Here,  lpat  is  a  pattern  that  matches  on the command line,
              corresponding to tpat which matches in the trial completion.

       l:lanchor|lpat=tpat
       L:lanchor|lpat=tpat
       l:lanchor||ranchor=tpat
       L:lanchor||ranchor=tpat
       b:lpat=tpat
       B:lpat=tpat
              These letters are for patterns  that  are  anchored  by  another
              pattern on the left side. Matching for lpat and tpat is as for m
              and M, but the pattern lpat matched on the command line must  be
              preceded  by  the  pattern lanchor.  The lanchor can be blank to
              anchor the match to  the  start  of  the  command  line  string;
              otherwise  the anchor can occur anywhere, but must match in both
              the command line and trial completion strings.

              If no lpat is given but a  ranchor  is,  this  matches  the  gap
              between  substrings  matched  by  lanchor  and  ranchor.  Unlike
              lanchor, the ranchor only needs to match  the  trial  completion
              string.

              The  b  and B forms are similar to l and L with an empty anchor,
              but need to match only the beginning of the trial completion  or
              the word on the command line, respectively.

       r:lpat|ranchor=tpat
       R:lpat|ranchor=tpat
       r:lanchor||ranchor=tpat
       R:lanchor||ranchor=tpat
       e:lpat=tpat
       E:lpat=tpat
              As  l, L, b and B, with the difference that the command line and
              trial completion patterns are anchored on the right side.   Here
              an  empty  ranchor  and the e and E forms force the match to the
              end of the trial completion or command line string.

       Each lpat, tpat or anchor is either an empty string or  consists  of  a
       sequence  of literal characters (which may be quoted with a backslash),
       question marks, character classes, and correspondence classes; ordinary
       shell patterns are not used.  Literal characters match only themselves,
       question marks match any character, and character classes are formed as
       for globbing and match any character in the given set.

       Correspondence classes are defined like character classes, but with two
       differences: they are delimited  by  a  pair  of  braces,  and  negated
       classes  are  not  allowed,  so  the characters ! and ^ have no special
       meaning directly after the opening brace.  They indicate that  a  range
       of  characters  on  the  line  match a range of characters in the trial
       completion, but (unlike ordinary character classes) paired according to
       the  corresponding  position  in the sequence. For example, to make any
       lowercase letter on the line match the corresponding  uppercase  letter
       in  the  trial  completion, you can use ‘m:{a-z}={A-Z}’.  More than one
       pair of classes can occur, in which case the first class before  the  =
       corresponds  to  the  first  after it, and so on.  If one side has more
       such classes than the other side, the superfluous classes  behave  like
       normal  character  classes.   In anchor patterns correspondence classes
       also behave like normal character classes.

       The pattern tpat may also be one or two stars, ‘*’ or ‘**’. This  means
       that the pattern on the command line can match any number of characters
       in the trial completion. In this case the pattern must be anchored  (on
       either  side); in the case of a single star, the anchor then determines
       how much of the  trial  completion  is  to  be  included  --  only  the
       characters  up  to  the  next appearance of the anchor will be matched.
       With two stars, substrings matched by the anchor can be matched, too.

       Examples:

       The keys of the options association defined by the parameter module are
       the  option  names  in  all-lowercase  form,  without  underscores, and
       without the optional no at  the  beginning  even  though  the  builtins
       setopt  and  unsetopt  understand  option names with uppercase letters,
       underscores, and the optional no.  The following  alters  the  matching
       rules  so that the prefix no and any underscore are ignored when trying
       to match the trial completions generated and uppercase letters  on  the
       line match the corresponding lowercase letters in the words:

              compadd -ML:|[nN][oO]= M:_= M:{A-Z}={a-z}- \
                ${(k)options}

       The  first  part says that the pattern ‘[nN][oO]’ at the beginning (the
       empty anchor before the pipe symbol) of the string on the line  matches
       the  empty  string  in the list of words generated by completion, so it
       will be ignored if present. The  second  part  does  the  same  for  an
       underscore anywhere in the command line string, and the third part uses
       correspondence classes so that any uppercase letter on the line matches
       the  corresponding  lowercase  letter  in  the  word.  The  use  of the
       uppercase forms of the specification characters (L  and  M)  guarantees
       that what has already been typed on the command line (in particular the
       prefix no) will not be deleted.

       Note that the use of L in the first part means  that  it  matches  only
       when  at  the  beginning  of both the command line string and the trial
       completion.  I.e.,  the  string  ‘_NO_f’  would  not  be  completed  to
       ‘_NO_foo’, nor would ‘NONO_f’ be completed to ‘NONO_foo’ because of the
       leading underscore or the second ‘NO’  on  the  line  which  makes  the
       pattern  fail  even though they are otherwise ignored. To fix this, one
       would use ‘B:[nN][oO]=’ instead of the first part. As described  above,
       this  matches  at the beginning of the trial completion, independent of
       other characters or substrings at the beginning  of  the  command  line
       word which are ignored by the same or other match-specs.

       The second example makes completion case insensitive.  This is just the
       same as in the option example,  except  here  we  wish  to  retain  the
       characters in the list of completions:

              compadd -Mm:{a-z}={A-Z}...

       This  makes  lowercase  letters match their uppercase counterparts.  To
       make uppercase letters match the lowercase forms as well:

              compadd -Mm:{a-zA-Z}={A-Za-z}...

       A nice example for the use of * patterns is  partial  word  completion.
       Sometimes  you  would  like  to  make  strings like ‘c.s.u’ complete to
       strings like ‘comp.source.unix’, i.e. the  word  on  the  command  line
       consists  of  multiple parts, separated by a dot in this example, where
       each part should be completed separately --  note,  however,  that  the
       case  where  each part of the word, i.e. ‘comp’, ‘source’ and ‘unix’ in
       this example, is to be completed from separate sets  of  matches  is  a
       different  problem to be solved by the implementation of the completion
       widget.  The example can be handled by:

              compadd -Mr:|.=* r:|=*\
                - comp.sources.unix comp.sources.misc ...

       The first specification says that  lpat  is  the  empty  string,  while
       anchor  is  a dot; tpat is *, so this can match anything except for the
       ‘.’ from the anchor in the trial completion word.  So in  ‘c.s.u’,  the
       matcher  sees ‘c’, followed by the empty string, followed by the anchor
       ‘.’, and likewise for the second dot, and replaces  the  empty  strings
       before  the  anchors,  giving ‘c[omp].s[ources].u[nix]’, where the last
       part of the completion is just as normal.

       With the pattern shown above, the string ‘c.u’ could not  be  completed
       to  ‘comp.sources.unix’  because  the  single  star  means  that no dot
       (matched by the anchor) can be  skipped.  By  using  two  stars  as  in
       ‘r:|.=**’,  however,  ‘c.u’  could be completed to ‘comp.sources.unix’.
       This also shows that in some cases, especially if the anchor is a  real
       pattern,  like a character class, the form with two stars may result in
       more matches than one would like.

       The second specification is needed to make this work when the cursor is
       in  the  middle  of  the  string  on  the  command  line and the option
       COMPLETE_IN_WORD is  set.  In  this  case  the  completion  code  would
       normally  try  to  match  trial completions that end with the string as
       typed so far, i.e. it will only insert new  characters  at  the  cursor
       position  rather then at the end.  However in our example we would like
       the code to recognise matches which contain extra characters after  the
       string  on  the line (the ‘nix’ in the example).  Hence we say that the
       empty string at  the  end  of  the  string  on  the  line  matches  any
       characters at the end of the trial completion.

       More generally, the specification

              compadd -Mr:|[.,_-]=* r:|=*...

       allows  one  to  complete  words  with  abbreviations before any of the
       characters  in  the  square  brackets.   For   example,   to   complete
       veryverylongfile.c  rather  than veryverylongheader.h with the above in
       effect, you can just type very.c before attempting completion.

       The specifications with both a left and a right anchor  are  useful  to
       complete  partial  words  whose parts are not separated by some special
       character. For example, in some places strings  have  to  be  completed
       that are formed ‘LikeThis’ (i.e. the separate parts are determined by a
       leading uppercase letter) or maybe one has  to  complete  strings  with
       trailing  numbers.  Here  one  could  use the simple form with only one
       anchor as in:

              compadd -Mr:|[A-Z0-9]=* r:|=*LikeTHIS FooHoo 5foo123 5bar234

       But with this, the string ‘H’ would neither complete to ‘FooHoo’ nor to
       ‘LikeTHIS’ because in each case there is an uppercase letter before the
       ‘H’ and that is matched by the anchor. Likewise, a  ‘2’  would  not  be
       completed.   In   both   cases   this   could   be   changed  by  using
       ‘r:|[A-Z0-9]=**’,  but  then  ‘H’  completes  to  both  ‘LikeTHIS’  and
       ‘FooHoo’  and a ‘2’ matches the other strings because characters can be
       inserted before every uppercase letter and digit.  To  avoid  this  one
       would use:

              compadd -Mr:[^A-Z0-9]||[A-Z0-9]=** r:|=*\
                  LikeTHIS FooHoo foo123 bar234

       By  using these two anchors, a ‘H’ matches only uppercase ‘H’s that are
       immediately preceded by something matching the left anchor ‘[^A-Z0-9]’.
       The  effect is, of course, that ‘H’ matches only the string ‘FooHoo’, a
       ‘2’ matches only ‘bar234’ and so on.

       When using the completion system (see zshcompsys(1)), users can  define
       match specifications that are to be used for specific contexts by using
       the matcher and matcher-list styles. The values for the latter will  be
       used everywhere.

COMPLETION WIDGET EXAMPLE

       The first step is to define the widget:

              zle -C complete complete-word complete-files

       Then  the  widget  can  be  bound  to  a  key using the bindkey builtin
       command:

              bindkey^X\tcomplete

       After that the shell function  complete-files  will  be  invoked  after
       typing  control-X  and  TAB.  The  function  should  then  generate the
       matches, e.g.:

              complete-files () { compadd - * }

       This function will complete files in the current directory matching the
       current word.