compgen
generate completion matches in bash
TLDR
List all commands
$ compgen -c
List commands starting with prefix$ compgen -c [ls]
List all aliases$ compgen -a
List all shell functions$ compgen -A function
List all builtins$ compgen -b
List all variables$ compgen -v
Complete from word list$ compgen -W '[start stop restart]' -- [sta]
List all users$ compgen -u
SYNOPSIS
compgen [options] [word]
DESCRIPTION
compgen is a Bash builtin that generates possible completion matches for a word. It is primarily used inside programmable completion functions but is also useful interactively for discovering available commands, functions, variables, and other shell entities. When given a word argument, only matches starting with that word are shown.
PARAMETERS
-a
Generate alias names.-b
Generate shell builtin names.-c
Generate command names (builtins, functions, and executables on PATH).-d
Generate directory names.-e
Generate names of exported shell variables.-f
Generate filenames.-g
Generate group names.-j
Generate job names.-k
Generate shell reserved words (keywords).-s
Generate service names.-u
Generate usernames.-v
Generate shell variable names.-A action
Generate completions using the given action. Valid actions include: alias, arrayvar, binding, builtin, command, directory, disabled, enabled, export, file, function, group, hostname, job, keyword, running, service, setopt, signal, stopped, user, variable.-F function
Call shell function to generate completions.-C command
Run command in a subshell and use its output as completions.-W wordlist
Split wordlist on IFS and generate matches from resulting words.-G pattern
Expand the glob pattern and use the results as completions.-P prefix
Prepend prefix to each generated completion.-S suffix
Append suffix to each generated completion.-X pattern
Filter completions using the pattern; a leading ! negates the filter.
CAVEATS
Bash builtin only, not available in other shells. Returns true unless invalid option or no matches. Used in completion scripts with complete builtin.