Regular expressions (sometimes called regexps) are expressions used for matching patterns of text. Regexes are used for everything from simple searches to complex search-and-replace procedures. If you have used the advanced mode on any of the major Internet search engines, then you have used regular expressions.
The purpose of this module is to familiarize you with the major features of Perl's regular expressions so that you can use this feature as effectively and seamlessly as possible. This is not intended to be an exhaustive regular expression tutorial; regular expressions can be a deep subject.
Many people, upon finding that regular expressions look cryptic, decide that they are too difficult and not worth the trouble. Do not judge too quickly! Once you get past that bad first impression, you will begin to use them more effectively and find your programs becoming smaller, faster, and more efficient--sometimes dramatically so!