Today I want to post a list of regex resources that have been useful for me. In the first time I haven’t read a regex book, I found all my knowledge on-line, and there is plenty of regex information out there.

On-line resources

• regular-expressions.info, a great online resource on every aspect of regular expressions and for the differences of the languages.
• stackoverflow regex faq, the collection of questions that got faq status

As example, because those languages provide good documentation and because I know them best, here the regex docs for Perl and C#. Especially the Perl tutorials can be recommended also to regex learners of other languages, just ignore the, by your language not supported, advanced parts.

Perl

• perlrequick, Perl regular expressions quick start, a tutorial that gives a basic regex understanding.
• perlretut, Perl regular expressions tutorial. A really extensive tutorial going into all details of Perl regexes.
• perlre, the Perl regex module documentation.

C#

• .NET Framework Regular Expressions, the introduction to .NET regular expressions.
• Details of Regular Expression Behavior, an advanced reading, not only for .NET users. Explains the details of the matching behaviour and the capabilities of the .NET Framework regex Engine.
• Regular Expression Language – Quick Reference

Online Regex Tester

• Regexr, my favourite one. Based on Flex, supports lookahead and fixed length lookbehind. Has also a regex community library and explain regex constructs. It is also possible to create permanent links to solutions.
• Rubular, based on Ruby, allows also to create permanent links.
• Regular Expression Analyzer, give it a regex and it will analyze it
• Refiddle, you can choose the regex engine (JavaScript, Ruby, .NET)

Applications

• RegexBuddy, the ultimate tool
• Regular Expression Designer, free alternative