regexp

Mastering Regular Expressions
$44.99
A nice look into the mechanics of regular expressions, starting from a birds eye view and diving down into the details.

Regular Expression Pocket Reference (Pocket Reference (O'Reilly))
$14.99
It is a very good guide. But I have to borrow the notes in the Vi section to use it with sed when I need to use a Regex.

A more practical guide on regex's and shell scripting would be better!

Regular Expressions Cookbook
$45.00
Jan Goyvaerts' and Steven Levithan's REGULAR EXPRESSIONS COOKBOOK provides over 100 recipes to help blend data and text with regular expressions, offering programmers and software development collections a powerful set of step-by-step instructions for using C#, Java, Perl, Python and VB.Net, among others. Learn how to format input, manage lines, find solutions for common markups and paths, and more in this advanced programmer's cookbook of basics.