SSH host name completion on a Mac

01 Oct 2009

The list of servers I have to ssh in to is continually growing many of them I need to have an ssh tunnel to get to so I fully use the ~/.ssh/config file to help me out. Now that my .ssh/config file has grown I am starting to forget what name of that one server was. On some unix boxes bash_completion is installed which allows you to type: ssh se[tab] and get: ssh bash_completion is not installed on the Mac by default. You can install it with macports but I have yet to run in to a real need to install macports yet so I started searching for any other ways to get this working on my Mac.

What I found was a comment on a MacOSXHints hint. All you need to do is throw this in your ~/.bash_profile file.

_complete_ssh_hosts ()
        comp_ssh_hosts=`cat ~/.ssh/known_hosts | \
                        cut -f 1 -d ' ' | \
                        sed -e s/,.*//g | \
                        grep -v ^# | \
                        uniq | \
                        grep -v "\[" ;
                if [ -f ~/.ssh/config ]; then
                        cat ~/.ssh/config | \
                                grep "^Host " | \
                                awk '{print $2}'
        COMPREPLY=( $(compgen -W "${comp_ssh_hosts}" -- $cur))
        return 0
complete -F _complete_ssh_hosts ssh

This will read in your .ssh/known_hosts file and your .ssh/config file and create a list of host names that you can now tab complete with the ssh command. Comes in very handy.