We all love the bash. And since we are are lazy, we love bash's history in particular. * Everyone knows that: one can go back in the history by hitting the "arrow up" key. * One can repeat any command from the history by typing !x, where x is the running number of the command in the history. * One can scroll though any command issued before and starting with the letter "l" with l * Even better: one can reverse search bash's history by typing ctrl+r.