ZSHCOMPWID(1) User Commands ZSHCOMPWID(1)

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 completion 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.

COMPLETION SPECIAL PARAMETERS

The parameters ZLE_REMOVE_SUFFIX_CHARS and ZLE_SPACE_SUFFIX_CHARS are
used by the completion mechanism, but are not special. See Parameters
Used By The Shell in zshparam(1).

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 ${. This
context will also be set when completing
parameter flags following ${(; the full command
line argument is presented and the handler must
test the value to be completed to ascertain that
this is the case.

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 completions 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 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 added 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_match (see below). 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 match 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.

COMPLETION BUILTIN COMMANDS

compadd [ -akqQfenUl12C ] [ -F array ]
[-P prefix ] [ -S suffix ]
[-p hidden-prefix ] [ -s hidden-suffix ]
[-i ignored-prefix ] [ -I ignored-suffix ]
[-W file-prefix ] [ -d array ]
[-J group-name ] [ -X explanation ] [ -x message ]
[-V group-name ] [ -o [ order ] ]
[-r remove-chars ] [ -R remove-func ]
[-D array ] [ -O array ] [ -A array ]
[-E number ]
[-M match-spec ] [ -- ] [ completions ... ]

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

The completion code breaks each match into seven fields in the
order:

<ipre><apre><hpre><body><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. <body> is the
part of the match that should appear in the list of matches
shown to the user. 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 each match.
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 each
match.

-p hidden-prefix
This gives a string that should be inserted before each
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 each
match.

-i ignored-prefix
This gives a string to insert just before any string
given with the `-P' option. Without `-P' the string is
inserted before the string given with `-p' or directly
before each match.

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

-a With this flag the completions are taken as names of
arrays and the actual completions are their values. If
only some elements of the arrays are needed, the
completions may also contain subscripts, as in
`foo[2,-1]'.

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

-d array
This adds per-completion display strings. The array
should contain one element per completion given. The
completion code will then display the first element
instead of the first completion, 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 completions,
the leftover completions will be displayed unchanged
and if there are more display strings than completions,
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 [ order ]
This controls the order in which matches are sorted.
order is a comma-separated list comprising the
following possible values. These values can be
abbreviated to their initial two or three characters.
Note that the order forms part of the group name space
so matches with different orderings will not be in the
same group.

match If 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). This is the default if `-o'
is specified but the order argument is omitted.

nosort This specifies that the completions are
pre-sorted and their order should be preserved.
This value only makes sense alone and cannot be
combined with any others.

numeric
If the matches include numbers, sort them
numerically rather than lexicographically.

reverse
Arrange the matches backwards by reversing the
sort ordering.

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

-V group-name
Like -J but naming an unsorted group. This option is
identical to the combination of -J and -o nosort.

-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.

Within the explanation, the following sequences may be
used to specify output attributes as described in the
section EXPANSION OF PROMPT SEQUENCES in zshmisc(1):
`%B', `%S', `%U', `%F', `%K' and their lower case
counterparts, as well as `%{...%}'. `%F', `%K' and
`%{...%}' take arguments in the same form as prompt
expansion. (Note that the sequence `%G' is not
available; an argument to `%{' should be used instead.)
The sequence `%%' produces a literal `%'.

These sequences are most often employed by users when
customising the format style (see zshcompsys(1)), but
they must also be taken into account when writing
completion functions, as passing descriptions with
unescaped `%' characters to utility functions such as
_arguments and _message may produce unexpected results.
If arbitrary text is to be passed in a description, it
can be escaped using e.g. ${my_str//\%/%%}.

-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 lower case 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 match has
been accepted and a suffix has been inserted, 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
the completions 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 match 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. completions
that match one of these patterns are ignored, that is,
not considered to be 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 matches when inserting them
into the command line.

-M match-spec
This gives local match specifications as described
below in the section `Completion 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 matching completions are to be added to
the set of matches, but are not to be listed to the
user.

-U If this flag is given, all completions are added to the
set of matches 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 completions are not added
to the set of matches. Instead, matching is done as
usual and all of the completions that match 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
completions which match being stored in array, the
strings generated internally by the completion code are
stored. For example, with a match specification of `-M
"L:|no="', a current word of `nof' and completions of
`foo', this option stores the string `nofoo' in the
array, whereas the -O option stores the `foo'
originally given.

-D array
As with -O, the completions are not added to the set of
matches. Instead, whenever the nth completion does not
match, the nth element of the array is removed.
Elements for which the corresponding completion matches
are retained. This option can be used more than once
to remove elements from multiple arrays.

-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 number
This option adds number empty matches after matching
completions 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
can be important to note as it affects the name space
into which matches are added.

-
-- This flag ends the list of flags and options. All
arguments after it will be taken as the completions
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 value of the PREFIX parameter is at least number
characters long, 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
numberth match is moved. If the number is negative,
the numberth 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 beginth 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
functions (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.

COMPLETION 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.

COMPLETION MATCHING CONTROL

When the user invokes completion, the current word on the command
line (that is, the word the cursor is currently on) is used to
generate a match pattern. Only those completions that match the
pattern are offered to the user as matches.

The default match pattern is generated from the current word by
either

+o appending a `*' (matching any number of characters in a
completion) or,

+o if the shell option COMPLETE_IN_WORD is set, inserting a `*'
at the cursor position.

This narrow pattern can be broadened selectively by passing a match
specification to the compadd builtin command through its -M option
(see `Completion Builtin Commands' above). A match specification
consists of one or more matchers separated by whitespace. Matchers
in a match specification are applied one at a time, from left to
right. Once all matchers have been applied, completions are compared
to the final match pattern and non-matching ones are discarded.

+o Note that the -M option is ignored if the current word
contains a glob pattern and the shell option GLOB_COMPLETE is
set or if the pattern_match key of the special associative
array compstate is set to a non-empty value (see `Completion
Special Parameters' above).

+o Users of the completion system (see zshcompsys(1)) should
generally not use the -M option directly, but rather use the
matcher-list and matcher styles (see the subsection Standard
Styles in the documentation for COMPLETION SYSTEM
CONFIGURATION in zshcompsys(1)).

Each matcher consists of

+o a case-sensitive letter

+o a `:',

+o one or more patterns separated by pipes (`|'),

+o an equals sign (`='), and

+o another pattern.

The patterns before the `=' are used to match substrings of the
current word. For each matched substring, the corresponding part of
the match pattern is broadened with the pattern after the `=', by
means of a logical OR.

Each pattern in a matcher cosists of either

+o the empty string or

+o a sequence of

+o literal characters (which may be quoted with a `\'),

+o question marks (`?'),

+o bracket expressions (`[...]'; see the subsection Glob
Operators in the documentation for GLOB OPERATORS in
zshexpn(1)), and/or

+o brace expressions (see below).


Other shell patterns are not allowed.

A brace expression, like a bracket expression, consists of a list of

+o literal characters,

+o ranges (`0-9'), and/or

+o character classes (`[:name:]').

However, they differ from each other as follows:

+o A brace expression is delimited by a pair of braces (`{...}').

+o Brace expressions do not support negations. That is, an
initial `!' or `^' has no special meaning and will be
interpreted as a literal character.

+o When a character in the current word matches the nth pattern
in a brace expression, the corresponding part of the match
pattern is broadened only with the nth pattern of the brace
expression on the other side of the `=', if there is one; if
there is no brace expression on the other side, then this
pattern is the empty string. However, if either brace
expression has more elements than the other, then the excess
entries are simply ignored. When comparing indexes, each
literal character or character class counts as one element,
but each range is instead expanded to the full list of literal
characters it represents. Additionally, if on both sides of
the `=', the nth pattern is `[:upper:]' or `[:lower:]', then
these are expanded as ranges, too.

Note that, although the matching system does not yet handle multibyte
characters, this is likely to be a future extension. Hence, using
`[:upper:]' and `[:lower:]' is recommended over `A-Z' and `a-z'.

Below are the different forms of matchers supported. Each uppercase
form behaves exactly like its lowercase counterpart, but adds an
additional step after the match pattern has filtered out non-matching
completions: Each of a match's substrings that was matched by a
subpattern from an uppercase matcher is replaced with the
corresponding substring of the current word. However, patterns from
lowercase matchers have higher weight: If a substring of the current
word was matched by patterns from both a lowercase and an uppercase
matcher, then the lowercase matcher's pattern wins and the
corresponding part of the match is not modified.

Unless indicated otherwise, each example listed assumes
COMPLETE_IN_WORD to be unset (as it is by default).

m:word-pat=match-pat
M:word-pat=match-pat

For each substring of the current word that matches word-pat,
broaden the corresponding part of the match pattern to
additionally match match-pat.

Examples:

m:{[:lower:]}={[:upper:]} lets any lower case character
in the current word be completed to itself or its
uppercase counterpart. So, the completions `foo',
`FOO' and `Foo' will are be considered matches for the
word `fo'.

M:_= inserts every underscore from the current word
into each match, in the same relative position,
determined by matching the substrings around it. So,
given a completion `foo', the word `f_o' will be
completed to the match `f_oo', even though the latter
was not present as a completion.

b:word-pat=match-pat
B:word-pat=match-pat
e:word-pat=match-pat
E:word-pat=match-pat

For each consecutive substring at the b:eginning or e:nd of
the current word that matches word-pat, broaden the
corresponding part of the match pattern to additionally match
match-pat.

Examples:

`b:-=+' lets any number of minuses at the start of the
current word be completed to a minus or a plus.

`B:0=' adds all zeroes at the beginning of the current
word to the beginning of each match.

l:|word-pat=match-pat
L:|word-pat=match-pat
R:word-pat|=match-pat
r:word-pat|=match-pat

If there is a substring at the l:eft or r:ight edge of the
current word that matches word-pat, then broaden the
corresponding part of the match pattern to additionally match
match-pat.

For each l:, L:, r: and R: matcher (including the ones below),
the pattern match-pat may also be a `*'. This matches any
number of characters in a completion.

Examples:

`r:|=*' appends a `*' to the match pattern, even when
COMPLETE_IN_WORD is set and the cursor is not at the
end of the current word.

If the current word starts with a minus, then `L:|-='
will prepend it to each match.

l:anchor|word-pat=match-pat
L:anchor|word-pat=match-pat
r:word-pat|anchor=match-pat
R:word-pat|anchor=match-pat

For each substring of the current word that matches word-pat
and has on its l:eft or r:ight another substring matching
anchor, broaden the corresponding part of the match pattern to
additionally match match-pat.

Note that these matchers (and the ones below) modify only what
is matched by word-pat; they do not change the matching
behavior of what is matched by anchor (or coanchor; see the
matchers below). Thus, unless its corresponding part of the
match pattern has been modified, the anchor in the current
word has to match literally in each completion, just like any
other substring of the current word.

If a matcher includes at least one anchor (which includes the
matchers with two anchors, below), then match-pat may also be
`*' or `**'. `*' can match any part of a completion that does
not contain any substrings matching anchor, whereas a `**' can
match any part of a completion, period. (Note that this is
different from the behavior of `*' in the anchorless forms of
`l:' and `r:' and and also different from `*' and `**' in glob
expressions.)

Examples:

`r:|.=*' makes the completion `comp.sources.unix' a
match for the word `..u' -- but not for the word `.u'.

Given a completion `--foo', the matcher `L:--|no-='
will complete the word `--no-' to the match `--no-foo'.

l:anchor||coanchor=match-pat
L:anchor||coanchor=match-pat
r:coanchor||anchor=match-pat
R:coanchor||anchor=match-pat

For any two consecutive substrings of the current word that
match anchor and coanchor, in the order given, insert the
pattern match-pat between their corresponding parts in the
match pattern.

Note that, unlike anchor, the pattern coanchor does not change
what `*' can match.

Examples:

`r:?||[[:upper:]]=*' will complete the current word
`fB' to `fooBar', but it will not complete it to
`fooHooBar' (because `*' here cannot match anything
that includes a match for `[[:upper:]]), nor will it
complete `B' to `fooBar' (because there is no character
in the current word to match coanchor).

Given the current word `pass.n' and a completion
`pass.byname', the matcher `L:.||[[:alpha:]]=by' will
produce the match `pass.name'.

x:

Ignore this matcher and all matchers to its right.

This matcher is used to mark the end of a match specification.
In a single standalone list of matchers, this has no use, but
where match specifications are concatenated, as is often the
case when using the completion system (see zshcompsys(1)), it
can allow one match specification to override another.

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\t' complete

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.

zsh 5.9 May 14, 2022 ZSHCOMPWID(1)