This is the second part of the catchily named Regex-for-people-who-should-know-regex-but-do-not guide. If you are unfamiliar with the basics of regular expression syntax, then I recommend you first read part 1, or any of the many regular expressions primers available online.

What follows is a repost of my first article on nulldigital.net, on the 10th of May 2006. A long time ago, when I was all innocent! Good times. The original article as been modified slightly as I sounded like such a git back then. I know it's slightly simple for this site but since nulldigital.net is closing I want to repost the articles from there to neverfear.org. So lets get started..

Regular expressions are very useful. If you have to deal with text at all, you will find them indispensable. In programming, they can be used to verify user input (e.g check an email is valid), sanitize input (make sure the user only used allowed characters), remove sections of the string (remove all non-alpha-numeric characters). And not just for programming! You can use regular expressions in many text editors to edit the current file. You can use them in the grep command to find very specific lines, or in the sed "stream editor" to edit out bits of a file..

The video

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