This manual is a printed edition of the official Perl reference documentation from the Perl 5.12.1 distribution. It describes the syntax of Perl and its built-in datatypes, operators, functions, variables, regular expressions and diagnostic messages.

This manual covers advanced topics, and is suitable for readers who need to be familiar with the details and rules of the Perl language. The modules in the standard Perl library are documented separately in "The Perl Library Reference Manual" (to be published).

This book corresponds to the latest release of Perl at the time of publication (August 2010).

Long-time Perl programmers will find many new features of the Perl language documented in this manual, such as the highly-useful "//" and "//=" operators, state variables, the "given/when" keywords and additional extended regex patterns.