Regular expression resources

This is the more-or-less official home page of the FreeNode∞ IRC channel #regex ( irc://irc.freenode.net/regex ). Come join us there for real-time support!

Introduction

Wikipedia:Regular_expression∞ is an excellent introductory article.
RegexAsk: how to get answers on #regex
RegexFAQ: frequently asked questions
perlretut∞ is a Perl regular expression tutorial.

Standards

• IEEE 1003.1 2003 (SUSv3)∞ documents both POSIX Basic Regular Expressions and POSIX Extended Regular Expressions.
• Perl 5∞ and PCRE∞ document Perl-Compatible Regular Expressions.

Book

Want to become a regex master? You must read Jeffrey Friedl's Mastering Regular Expressions∞.

Tools

Rex V: an AJAX Regular EXpression eValuator∞
QuickRex Plugin for Eclipse∞

Implementation-specific references

• C (POSIX API) SUSv3 regex.h∞
• C PCRE library∞
• Perl perlre - perldoc.perl.org∞
• Java java.util.regex (Java 2 Platform SE v1.4.2)∞
• Java java.util.regex (Java 2 Platform SE v5.0)∞
• PHP Regular Expression Functions (Perl-Compatible) - Manual∞
• PHP Regular Expression Functions (POSIX Extended) - Manual∞
• .NET Framework Regular Expressions∞
• Python 4.2 re -- Regular expression operations∞
• JavaScript - Core JavaScript 1.5 Guide - Regular Expressions∞
• Tcl Built-In Commands - re_syntax manual page∞
• Ruby (current) Class and Library Reference: Regexp∞ String∞ NB: The official Ruby releases (as of 1.8.x) use a modified implementation of GNU Regex∞. Newer versions of Ruby will use Oniguruma∞.
  
• mod_rewrite - Apache HTTP Server Version 1.3∞ 2.0∞ 2.2∞
• Lua: 5.0 reference manual∞ Lua: 5.1 reference manual∞
• Adobe Flex 3 Regular expression syntax∞ literals∞ RegExp class∞

Implementation notes

Notes on TextPad∞

• The ERE ( ) grouping operator is spelled \( \) in TextPad
• The ERE { } quantifier operator is spelled \{ \} in TextPad
• The ERE | alternation operator is spelled \| in TextPad

RegexExamples: example programs