That's basic regular expression syntax. Learning that will go a long way in helping you learn a lot of tools in Unix, including grep, sed, vim, emacs, perl (whi

That's basic regular expression syntax. Learning that will go a long way in helping you learn a lot of tools in Unix, including grep, sed, vim, emacs, perl (which generally has a slightly different syntax, but one that matches in this case), bash programming in general, and more.