The tables are meant to serve as an accelerated regex course, and they are meant to be read slowly, one line at a time. On each line, in the leftmost column, you will find a new element of regex syntax.

Describes a regular expressions technique to match a word or pattern except in certain contexts: excluding tags, ignoring contents, word blacklist.

This example gives you an idea of what you have to do to validate numbers within a certain range using regular expressions—and of why you should probably look for other methods first.

Grepping with PCRE and testing PCRE expressions. Explains the pcregrep (grep) and pcretest PCRE regex utilities, including PCRE2 versions. Includes download of Windows binaries.

How to specify the regex replacement for a string depending on its value. Presents regex trick for use in a text editor.

Regular Expressions History. Discusses the history of regular expressions, in particular the difference between regex and regular expressions in the mathematical sense.

Regex Quantifiers Tutorial. Explains the fine details of quantifiers, including greedy, lazy (reluctant) and possessive.

Regex humor. Features cartoons, jokes, quotes and quips about regular expressions.

There are great examples of regex recursion in several sections of the site. These will show you practical ways to use recursion in situations we haven't explored here.

Whenever I start playing with the regex features of a new language, the thing I always miss the most is a complete working program that performs the most common regex tasks—and some not-so-common …