If you type 'history' (without the quotes) in your x-term, it'll pop up a list of the last 500 commands you've attempted to execute. Each one is numbered. Say you scroll back in the list a bit and you see psx4m is number 437, in your x-term simply type: !437 (and hit enter) It'll run that command. You can also create aliases in your shell config file - for bash it's .bashrc (if you are root), for the 'user' account I believe you can use .profile - though don't quote me on that : )