complete / compgen

Programmable completion specification and generation.

Source: src/execution/builtins.f90:3808-4158

Synopsis

complete [-r] [-p] [-W wordlist] [-F function] [-A action] [-o option] [-P prefix] [-S suffix] [-X pattern] command [...]
compgen -W wordlist [prefix]

Description

complete registers, lists, or removes tab-completion rules for commands. compgen generates completions from a word list, useful for testing specs or in completion functions.

complete

Registering Completions

# Static word list
complete -W "start stop restart status" myservice

# Shell function
complete -F _git_complete git

# Built-in action
complete -A directory cd

# Combine options
complete -A file -o filenames -P "--file=" mycommand

Options

Flag	Argument	Description
`-W`	`wordlist`	Space-separated list of completion words
`-F`	`funcname`	Shell function to call for completions
`-A`	`action`	Built-in completion action (see below)
`-o`	`option`	Completion behavior option (see below)
`-P`	`prefix`	String prepended to each completion
`-S`	`suffix`	String appended to each completion
`-X`	`pattern`	Filter pattern — matching completions are removed
`-r`	—	Remove completion specs for the named commands
`-p`	—	List all registered specs in reusable format

Actions (`-A`)

Action	Completes with
`alias`	Defined aliases
`builtin`	Shell builtins
`command`	Commands on PATH
`directory`	Directories
`file`	Files
`function`	Shell functions
`hostname`	Hostnames
`keyword`	Shell keywords
`variable`	Shell variables
`user`	System users
`group`	System groups
`service`	System services
`export`	Exported variables

Options (`-o`)

Option	Effect
`default`	Fall back to default completion if no matches
`dirnames`	Also complete directory names
`filenames`	Treat completions as filenames (add trailing `/` for dirs)
`nospace`	Don't add trailing space after completion
`plusdirs`	Add directory completions to the results
`nosort`	Don't sort completions alphabetically

List and Remove

complete -p           # List all registered specs
complete -r mycommand # Remove spec for mycommand
complete -r           # Remove all specs

compgen

Generate completions from a word list, optionally filtered by a prefix:

compgen -W "start stop restart status" st
# start
# stop
# status

Currently only the -W flag is supported for compgen.

Exit Status

Builtin	Status	Condition
`complete`	0	Success
`complete`	1	Invalid action, invalid option, or missing arguments
`compgen`	0	Matches found
`compgen`	1	No matches

Examples

# Complete hostnames for ssh
complete -A hostname ssh

# Custom completion function
_myapp_complete() {
    local cur="${COMP_WORDS[COMP_CWORD]}"
    compgen -W "build test deploy" "$cur"
}
complete -F _myapp_complete myapp