Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

While running the complete command on my gnome-terminal, it shows some commands.What are they? And what is the use of complete command?

$ complete
complete -F _minimal 
complete -F _filedir_xspec oodraw
complete -F _filedir_xspec elinks
complete -F _filedir_xspec freeamp
complete -F _longopt split
complete -F _longopt sed
complete -F _longopt ld
complete -F _longopt grep
complete -F _service /etc/init.d/vboxweb-service
complete -F _service /etc/init.d/vboxballoonctrl-service
complete -F _service /etc/init.d/rc
complete -F _service /etc/init.d/nmbd
complete -F _service /etc/init.d/halt
complete -j -P '"%' -S '"' jobs
complete -d pushd

List goes long, so i posted some of the them.

share|improve this question
I tried 'man complete' command but it displays nothing. – Avinash Raj Apr 4 '14 at 7:39
try help complete – Sylvain Pineau Apr 4 '14 at 7:45
up vote 9 down vote accepted

complete is a bash builtin function. So there is not a binary on the system. It handles how commands will be completed when pressing tab.

Example: if you type:

user@host:~$ pidof <tab><tab>

...a list is appearing with all possible values for this command. In this case it means all running processes. See the output of the complete function:

user@host:~$ complete | grep pidof
complete -F _pgrep pidof

This means that the function _pgrep (-F) is executed when tabbing the command pidof. The definition of this function is in /etc/bash_completion.d/procps.

Another example: if you type:

user@host:~$ cd /usr/<tab><tab>
bin/     games/   include/ lib/     lib32/   local/   sbin/    share/   src/ see the list of folders you can cd to under /usr/. Which function is executed? greping the complete function (as above) tells us it's the funtction _cd in /etc/bash_completion.

Do it yourself: You have a program/script called /bin/myprog and you want that if you execute it as follows

user@host:~$ myprog /home/user/<tab><tab> should only list folders, not files. So extend your bash completion with the following command:

user@host:~$ complete -F _cd myprog

That's it. You can also write own functions to complete custom things, for example complete only specific files or numbers or lists of static values...

share|improve this answer
So that's how git's command line completion seems so much smarter than most program's... – AShelly Apr 4 '14 at 11:06

complete is a bash command used to perform the auto-complete action when the user hit the TAB key in a terminal.

Calling just complete will list all the functions registered for auto-completion of commands or services options.

From the bash man pages:

complete: complete [-abcdefgjksuv] [-pr] [-DE] [-o option] [-A action] [-G globpat]
          [-W wordlist]  [-F function] [-C command] [-X filterpat] [-P prefix]
          [-S suffix] [name ...]
    Specify how arguments are to be completed by Readline.

    For each NAME, specify how arguments are to be completed.  If no options
    are supplied, existing completion specifications are printed in a way that
    allows them to be reused as input.

      -p    print existing completion specifications in a reusable format
      -r    remove a completion specification for each NAME, or, if no
        NAMEs are supplied, all completion specifications
      -D    apply the completions and actions as the default for commands
        without any specific completion defined
      -E    apply the completions and actions to "empty" commands --
        completion attempted on a blank line

    When completion is attempted, the actions are applied in the order the
    uppercase-letter options are listed above.  The -D option takes
    precedence over -E.

    Exit Status:
    Returns success unless an invalid option is supplied or an error occurs.

Check /usr/share/bash-completion/bash_completion to see the default completions that come with bash.

Visit for a full tutorial about this command.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.