Regular Expression Reference

We've only scratched the surface on regular expressions. This is a very complex topic that extends well beyond the scope of this book. Even so, we want to make sure you know where you can go quench your thirst for more information on regular expressions.

In PowerShell you can run Help about_regular_expression to view PowerShell's documentation on the topic. If you'd like a book recommendation,_Mastering Regular Expressions by Jeffrey Friedl (O'Reilly) is now in its Second Edition and is considered by many to be a definitive reference.

As you might expect, there are many excellent online resources. Here is a short list of our favorites:

• The official Microsoft documentation can be found at http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpgenref/html/cpconregularexpressionslanguageelements.asp.

• Regexlib.com has an online regular expression tester and a terrific one page "cheat sheet".

• Wikipedia has a great article on regular expressions including historical background at: http://en.wikipedia.org/wiki/Regular_expression.

• http://www.regular-expressions.info offers some nice tutorials and general information about regular expressions.

Finally, there are a number of free tools you can download that will help you evaluate and test regular expressions:

• Regex Coach (http://www.weitz.de/regex-coach/)

• Regular Expression Workbench 3.1 (http://www.gotdotnet.com/Community/UserSamples/Details.aspx?SampleGuid=)

• Expresso (http://www.codeproject.com/dotnet/expresso.asp)