21 Completion Using compctl

Filenames and file system paths.

Just file system paths.

Command names, including aliases, shell functions, builtins and reserved words.

Function names.

Names of builtin commands.

Names of external commands.

Reserved words.

Alias names.

Names of regular (non-global) aliases.

Names of global aliases.

This can be combined with -F, -B, -w, -a, -R and -G to get names of disabled functions, builtins, reserved words or aliases.

This option (to show enabled commands) is in effect by default, but may be combined with -d; -de in combination with -F, -B, -w, -a, -R and -G will complete names of functions, builtins, reserved words or aliases whether or not they are disabled.

Names of shell options (see Options).

Names of any variable defined in the shell.

Names of scalar (non-array) parameters.

Array names.

Names of integer variables.

Names of read-only variables.

Names of parameters used by the shell (including special parameters).

Names of shell special parameters.

Names of environment variables.

Named directories.

Key binding names.

Job names: the first word of the job leader’s command line. This is useful with the kill builtin.

Names of running jobs.

Names of suspended jobs.

User names.

Names taken from the elements of $array (note that the ‘$’ does not appear on the command line). Alternatively, the argument array itself may be a set of space- or comma-separated values in parentheses, in which any delimiter may be escaped with a backslash; in this case the argument should be quoted. For example,

compctl -k "(cputime filesize datasize stacksize
	       coredumpsize resident descriptors)" limit

The globstring is expanded using filename globbing; it should be quoted to protect it from immediate expansion. The resulting filenames are taken as the possible completions. Use ‘*(/)’ instead of ‘*/’ for directories. The fignore special parameter is not applied to the resulting files. More than one pattern may be given separated by blanks. (Note that brace expansion is not part of globbing. Use the syntax ‘(either|or)’ to match alternatives.)

The subststring is split into words and these words are than expanded using all shell expansion mechanisms (see Expansion). The resulting words are taken as possible completions. The fignore special parameter is not applied to the resulting files. Note that -g is faster for filenames.

Call the given function to get the completions. Unless the name starts with an underscore, the function is passed two arguments: the prefix and the suffix of the word on which completion is to be attempted, in other words those characters before the cursor position, and those from the cursor position onwards. The whole command line can be accessed with the -c and -l flags of the read builtin. The function should set the variable reply to an array containing the completions (one completion per element); note that reply should not be made local to the function. From such a function the command line can be accessed with the -c and -l flags to the read builtin. For example,

function whoson { reply=(`users`); }
compctl -K whoson talk

completes only logged-on users after ‘talk’. Note that ‘whoson’ must return an array, so ‘reply=`users`’ would be incorrect.

The possible completions are taken from the last num history lines. Only words matching pattern are taken. If num is zero or negative the whole history is searched and if pattern is the empty string all words are taken (as with ‘*’). A typical use is

compctl -D -f + -H 0 ''

which forces completion to look back in the history list for a word if no filename matches.

This instructs the shell not to quote any metacharacters in the possible completions. Normally the results of a completion are inserted into the command line with any metacharacters quoted so that they are interpreted as normal characters. This is appropriate for filenames and ordinary strings. However, for special effects, such as inserting a backquoted expression from a completion array (-k) so that the expression will not be evaluated until the complete line is executed, this option must be used.

The prefix is inserted just before the completed string; any initial part already typed will be completed and the whole prefix ignored for completion purposes. For example,

compctl -j -P "%" kill

inserts a ‘%’ after the kill command and then completes job names.

When a completion is found the suffix is inserted after the completed string. In the case of menu completion the suffix is inserted immediately, but it is still possible to cycle through the list of completions by repeatedly hitting the same key.

With directory file-prefix: for command, file, directory and globbing completion (options -c, -f, -/, -g), the file prefix is implicitly added in front of the completion. For example,

compctl -/ -W ~/Mail maildirs

completes any subdirectories to any depth beneath the directory ~/Mail, although that prefix does not appear on the command line. The file-prefix may also be of the form accepted by the -k flag, i.e. the name of an array or a literal list in parenthesis. In this case all the directories in the list will be searched for possible completions.

If used with a suffix as specified by the -S option, this causes the suffix to be 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; this the same rule used for the AUTO_REMOVE_SLASH option. The option is most useful for list separators (comma, colon, etc.).

This option restricts the range of command line words that are considered to be arguments. If combined with one of the extended completion patterns ‘p[...]’, ‘r[...]’, or ‘R[...]’ (see Extended Completion below) the range is restricted to the range of arguments specified in the brackets. Completion is then performed as if these had been given as arguments to the cmd supplied with the option. If the cmd string is empty the first word in the range is instead taken as the command name, and command name completion performed on the first word in the range. For example,

compctl -x 'r[-exec,;]' -l '' -- find

completes arguments between ‘-exec’ and the following ‘;’ (or the end of the command line if there is no such string) as if they were a separate command line.

Normally zsh completes quoted strings as a whole. With this option, completion can be done separately on different parts of such strings. It works like the -l option but makes the completion code work on the parts of the current word that are separated by spaces. These parts are completed as if they were arguments to the given cmd. If cmd is the empty string, the first part is completed as a command name, as with -l.

Use the whole list of possible completions, whether or not they actually match the word on the command line. The word typed so far will be deleted. This is most useful with a function (given by the -K option) which can examine the word components passed to it (or via the read builtin’s -c and -l flags) and use its own criteria to decide what matches. If there is no completion, the original word is retained. Since the produced possible completions seldom have interesting common prefixes and suffixes, menu completion is started immediately if AUTO_MENU is set and this flag is used.

The list provided by func-or-var is displayed instead of the list of completions whenever a listing is required; the actual completions to be inserted are not affected. It can be provided in two ways. Firstly, if func-or-var begins with a $ it defines a variable, or if it begins with a left parenthesis a literal array, which contains the list. A variable may have been set by a call to a function using the -K option. Otherwise it contains the name of a function which will be executed to create the list. The function will be passed as an argument list all matching completions, including prefixes and suffixes expanded in full, and should set the array reply to the result. In both cases, the display list will only be retrieved after a complete list of matches has been created.

Note that the returned list does not have to correspond, even in length, to the original set of matches, and may be passed as a scalar instead of an array. No special formatting of characters is performed on the output in this case; in particular, newlines are printed literally and if they appear output in columns is suppressed.

Print explanation when trying completion on the current set of options. A ‘%n’ in this string is replaced by the number of matches that were added for this explanation string. The explanation only appears if completion was tried and there was no unique match, or when listing completions. Explanation strings will be listed together with the matches of the group specified together with the -X option (using the -J or -V option). If the same explanation string is given to multiple -X options, the string appears only once (for each group) and the number of matches shown for the ‘%n’ is the total number of all matches for each of these uses. In any case, the explanation string will only be shown if there was at least one match added for the explanation string.

The sequences %B, %b, %S, %s, %U, and %u specify output attributes (bold, standout, and underline), %F, %f, %K, %k specify foreground and background colours, and %{...%} can be used to include literal escape sequences as in prompts.

Identical to -X, except that the explanation first undergoes expansion following the usual rules for strings in double quotes. The expansion will be carried out after any functions are called for the -K or -y options, allowing them to set variables.

The continue-string contains a character that specifies which set of completion flags should be used next. It is useful:

(i) With -T, or when trying a list of pattern completions, when compctl would usually continue with ordinary processing after finding matches; this can be suppressed with ‘-tn’.

(ii) With a list of alternatives separated by +, when compctl would normally stop when one of the alternatives generates matches. It can be forced to consider the next set of completions by adding ‘-t+’ to the flags of the alternative before the ‘+’.

(iii) In an extended completion list (see below), when compctl would normally continue until a set of conditions succeeded, then use only the immediately following flags. With ‘-t-’, compctl will continue trying extended completions after the next ‘-’; with ‘-tx’ it will attempt completion with the default flags, in other words those before the ‘-x’.

This gives the name of the group the matches should be placed in. Groups are listed and sorted separately; likewise, menu completion will offer the matches in the groups in the order in which the groups were defined. If no group name is explicitly given, the matches are stored in a group named default. The first time a group name is encountered, a group with that name is created. After that all matches with the same group name are stored in that group.

This can be useful with non-exclusive alternative completions. For example, in

compctl -f -J files -t+ + -v -J variables foo

both files and variables are possible completions, as the -t+ forces both sets of alternatives before and after the + to be considered at once. Because of the -J options, however, all files are listed before all variables.

Like -J, but matches within the group will not be sorted in listings nor in menu completion. These unsorted groups are in a different name space from the sorted ones, so groups defined as -J files and -V files are distinct.

If given together with the -V option, makes only consecutive duplicates in the group be removed. Note that groups with and without this flag are in different name spaces.

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.

This defines additional matching control specifications that should be used only when testing words for the list of flags this flag appears in. The format of the match-spec string is described in Completion Matching Control.