| .TH PCRE 3 |
| .SH NAME |
| PCRE - Perl-compatible regular expressions |
| .SH INTRODUCTION |
| .rs |
| .sp |
| The PCRE library is a set of functions that implement regular expression |
| pattern matching using the same syntax and semantics as Perl, with just a few |
| differences. Some features that appeared in Python and PCRE before they |
| appeared in Perl are also available using the Python syntax, there is some |
| support for one or two .NET and Oniguruma syntax items, and there is an option |
| for requesting some minor changes that give better JavaScript compatibility. |
| .P |
| The current implementation of PCRE corresponds approximately with Perl 5.12, |
| including support for UTF-8 encoded strings and Unicode general category |
| properties. However, UTF-8 and Unicode support has to be explicitly enabled; it |
| is not the default. The Unicode tables correspond to Unicode release 6.0.0. |
| .P |
| In addition to the Perl-compatible matching function, PCRE contains an |
| alternative function that matches the same compiled patterns in a different |
| way. In certain circumstances, the alternative function has some advantages. |
| For a discussion of the two matching algorithms, see the |
| .\" HREF |
| \fBpcrematching\fP |
| .\" |
| page. |
| .P |
| PCRE is written in C and released as a C library. A number of people have |
| written wrappers and interfaces of various kinds. In particular, Google Inc. |
| have provided a comprehensive C++ wrapper. This is now included as part of the |
| PCRE distribution. The |
| .\" HREF |
| \fBpcrecpp\fP |
| .\" |
| page has details of this interface. Other people's contributions can be found |
| in the \fIContrib\fP directory at the primary FTP site, which is: |
| .sp |
| .\" HTML <a href="ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre"> |
| .\" </a> |
| ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre |
| .P |
| Details of exactly which Perl regular expression features are and are not |
| supported by PCRE are given in separate documents. See the |
| .\" HREF |
| \fBpcrepattern\fP |
| .\" |
| and |
| .\" HREF |
| \fBpcrecompat\fP |
| .\" |
| pages. There is a syntax summary in the |
| .\" HREF |
| \fBpcresyntax\fP |
| .\" |
| page. |
| .P |
| Some features of PCRE can be included, excluded, or changed when the library is |
| built. The |
| .\" HREF |
| \fBpcre_config()\fP |
| .\" |
| function makes it possible for a client to discover which features are |
| available. The features themselves are described in the |
| .\" HREF |
| \fBpcrebuild\fP |
| .\" |
| page. Documentation about building PCRE for various operating systems can be |
| found in the \fBREADME\fP and \fBNON-UNIX-USE\fP files in the source |
| distribution. |
| .P |
| The library contains a number of undocumented internal functions and data |
| tables that are used by more than one of the exported external functions, but |
| which are not intended for use by external callers. Their names all begin with |
| "_pcre_", which hopefully will not provoke any name clashes. In some |
| environments, it is possible to control which external symbols are exported |
| when a shared library is built, and in these cases the undocumented symbols are |
| not exported. |
| . |
| . |
| .SH "USER DOCUMENTATION" |
| .rs |
| .sp |
| The user documentation for PCRE comprises a number of different sections. In |
| the "man" format, each of these is a separate "man page". In the HTML format, |
| each is a separate page, linked from the index page. In the plain text format, |
| all the sections, except the \fBpcredemo\fP section, are concatenated, for ease |
| of searching. The sections are as follows: |
| .sp |
| pcre this document |
| pcre-config show PCRE installation configuration information |
| pcreapi details of PCRE's native C API |
| pcrebuild options for building PCRE |
| pcrecallout details of the callout feature |
| pcrecompat discussion of Perl compatibility |
| pcrecpp details of the C++ wrapper |
| pcredemo a demonstration C program that uses PCRE |
| pcregrep description of the \fBpcregrep\fP command |
| pcrejit discussion of the just-in-time optimization support |
| pcrelimits details of size and other limits |
| pcrematching discussion of the two matching algorithms |
| pcrepartial details of the partial matching facility |
| .\" JOIN |
| pcrepattern syntax and semantics of supported |
| regular expressions |
| pcreperform discussion of performance issues |
| pcreposix the POSIX-compatible C API |
| pcreprecompile details of saving and re-using precompiled patterns |
| pcresample discussion of the pcredemo program |
| pcrestack discussion of stack usage |
| pcresyntax quick syntax reference |
| pcretest description of the \fBpcretest\fP testing command |
| pcreunicode discussion of Unicode and UTF-8 support |
| .sp |
| In addition, in the "man" and HTML formats, there is a short page for each |
| C library function, listing its arguments and results. |
| . |
| . |
| .SH AUTHOR |
| .rs |
| .sp |
| .nf |
| Philip Hazel |
| University Computing Service |
| Cambridge CB2 3QH, England. |
| .fi |
| .P |
| Putting an actual email address here seems to have been a spam magnet, so I've |
| taken it away. If you want to email me, use my two initials, followed by the |
| two digits 10, at the domain cam.ac.uk. |
| . |
| . |
| .SH REVISION |
| .rs |
| .sp |
| .nf |
| Last updated: 24 August 2011 |
| Copyright (c) 1997-2011 University of Cambridge. |
| .fi |