I'm sure you've noticed by now. One of the things you end up doing a lot in shells and scripting languages is parsing text. We've done it many times in articles on this blog. We've seen it in many articles on other blogs. We've all sat in quiet reverence of the wondrous power that is Regular Expressions.
And you want to be part of the Regex Illuminati.
Eric has just started a series of exercises on Learning Regular Expresions. In his words, this is
"The first in a series of exercises designed to teach you more about regular expressions, written by a guy who got partway through writing a regex book."
I find Eric's "Regular Expression Workbench" to be invaluable in working with regular expressions. I think you'll enjoy (or at least benefit from!) this series of articles.
Pay close attention -- I'll be blogging a script in the near future that will turn your regular expression skills into Real Ultimate Power. Regular expressions are cool; and by cool, I mean totally sweet.