Shellfun: Let the past come to haunt you!

OpenBSD's standard ksh shell has a feature I didn't learn for a long time: It allows you to search through past used commands (the "history" - Other modern shells have similar mechanisms, I'll follow OpenBSD's ksh here anyway.). Most people are familiar with using the arrow keys to go step by step back through the history to re-use a command you used a while ago, instead of typing it in again and again.

But it could get tiresome when you would have to step through a lot of commands to find that clever assortment of pipes and redirections with just the right set of parameters on that command you used 4 hours ago. What you can do there is what man ksh describes as "search-history". You pull it up with ^R (control-r) and start typing a few characters that you remember from your command line. "search-history" will then start to autocomplete with what it finds from your command history. Typing ^R again will get you the "next find" in the list, ^C will cancel the search and of course you can edit the line that you got. As usual, man ksh has a bit more information (grep for "search-history" in there).