ZSHCOMPWID(1) General Commands Manual 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
• appending a `*' (matching any number of characters in a
completion) or,
• 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.
• 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).
• 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
• a case-sensitive letter
• a `:',
• one or more patterns separated by pipes (`|'),
• an equals sign (`='), and
• 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
• the empty string or
• a sequence of
• literal characters (which may be quoted with a `\'),
• question marks (`?'),
• bracket expressions (`[...]'; see the subsection Glob
Operators in the documentation for GLOB OPERATORS in
zshexpn(1)), and/or
• brace expressions (see below).
Other shell patterns are not allowed.
A brace expression, like a bracket expression, consists of a list of
• literal characters,
• ranges (`0-9'), and/or
• character classes (`[:name:]').
However, they differ from each other as follows:
• A brace expression is delimited by a pair of braces (`{...}').
• Brace expressions do not support negations. That is, an initial
`!' or `^' has no special meaning and will be interpreted as a
literal character.
• 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)