Shell scripts are often used as glue, for automation and simple one-off tasks. What are some of your favorite "hidden" features of the Bash shell/scripting language?
insert preceding line's final parameter
alt-. the most useful key combination ever, try it and see, for some reason no one knows about this one.
press it again and again to select older last parameters.
great when you want to do something else to something you used just a moment ago.