Perl Compatible Regular Expressions

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Perl Compatible Regular Expressions (PCRE) is a regular expression C library inspired by Perl's external interface, written by Philip Hazel. PCRE's syntax is much more powerful and flexible than either of the POSIX regular expression flavors and many classic regular expression libraries. The name is misleading, because PCRE is Perl-compatible only if you consider a subset of PCRE's settings and a subset of Perl's regular expression facilities. The PCRE library is incorporated into a number of prominent open-source programs, such as the Apache HTTP Server and the PHP and R scripting languages. As of Perl 5.9.4, PCRE is also available as a replacement for Perl's default regular expression engine through the re::engine::PCRE module.