It's silly I've waited this may years to go figure this out. Many of you
may already know that modern installs of OpenSSH will tab complete
hostnames based on what's in the /etc/hosts file. But there is a neat
little addition to your .bashrc that will tack on the ability to tab
complete hostnames based on what's in ~/.ssh/known_hosts. Add this to
your .bashrc:
SSH_COMPLETE=( $(cat ~/.ssh/known_hosts | \\ cut -f 1 -d " " | \\sed -e s/,.*//g | \\ uniq ) )complete -o default -W "${SSH_COMPLETE[*]}" ssh
All your new shells will auto complete based on what hosts you've
connected to once (and therefore have entries in the known_hosts file).
Any host you've never visited, well it won't be there. If you want to
filter it based on certain hosts (for example, hosts in a certain domain
name), just add a | grep domain.com after the uniq. If you're like
me, this will save a lot of keystrokes over the next few years.
Tip: If you cut and paste my text above and it gives errors, make sure your cut-n-paste didn't change the quotes. If you want to see what it's going to use (or troubleshoot/modify), you can run this on the command line:
cat ~/.ssh/known_hosts | \\ cut -f 1 -d " " | \\ sed -e s/,.*//g | \\ uniq