I wrote down this handy little cheat sheet that covers the basics of POSIX and RegEx. RegEx is very powerful. It’s also a pain to use. Well, it’s easy to use. It’s a pain to implement in your searches, because it’s very very odd looking. It’s just a tiny step above hieroglyphs.
Thanks to crazygrrl, evolt, regex.com for providing the basis for me to build/copy/write/steal this document. This is by no means my original work. It’s just a compliation.