Bash completion essentials

Everyday completion

TAB completes commands, paths and other words. A second TAB may list alternatives depending on Readline configuration.

Check configuration

type _init_completion
complete -p ssh
shopt -p progcomp

How it works

Bash invokes a completion specification for a command, if registered. The completion function examines command-line context and returns candidates.

Common commands

complete -p
compgen -c -- sys
help complete
help compgen