trunk/doc/pcre.3

.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
1	nigel	41	.TH PCRE 3
2			.SH NAME
3	nigel	63	PCRE - Perl-compatible regular expressions
4	nigel	75	.SH INTRODUCTION
5	nigel	63	.rs
6			.sp
7	nigel	41	The PCRE library is a set of functions that implement regular expression
8	nigel	63	pattern matching using the same syntax and semantics as Perl, with just a few
9	ph10	456	differences. Some features that appeared in Python and PCRE before they
10			appeared in Perl are also available using the Python syntax, there is some
11			support for one or two .NET and Oniguruma syntax items, and there is an option
12			for requesting some minor changes that give better JavaScript compatibility.
13	nigel	75	.P
14	ph10	572	The current implementation of PCRE corresponds approximately with Perl 5.12,
15			including support for UTF-8 encoded strings and Unicode general category
16			properties. However, UTF-8 and Unicode support has to be explicitly enabled; it
17	ph10	598	is not the default. The Unicode tables correspond to Unicode release 6.0.0.
18	nigel	93	.P
19			In addition to the Perl-compatible matching function, PCRE contains an
20	ph10	456	alternative function that matches the same compiled patterns in a different
21			way. In certain circumstances, the alternative function has some advantages.
22			For a discussion of the two matching algorithms, see the
23	nigel	77	.\" HREF
24			\fBpcrematching\fP
25			.\"
26			page.
27			.P
28	nigel	75	PCRE is written in C and released as a C library. A number of people have
29	nigel	77	written wrappers and interfaces of various kinds. In particular, Google Inc.
30			have provided a comprehensive C++ wrapper. This is now included as part of the
31			PCRE distribution. The
32			.\" HREF
33			\fBpcrecpp\fP
34			.\"
35			page has details of this interface. Other people's contributions can be found
36	ph10	583	in the \fIContrib\fP directory at the primary FTP site, which is:
37	nigel	75	.sp
38	nigel	63	.\" HTML <a href="ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre">
39			.\" </a>
40			ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre
41	nigel	75	.P
42	nigel	63	Details of exactly which Perl regular expression features are and are not
43			supported by PCRE are given in separate documents. See the
44			.\" HREF
45	ph10	583	\fBpcrepattern\fP
46	nigel	63	.\"
47			and
48			.\" HREF
49	ph10	583	\fBpcrecompat\fP
50	nigel	63	.\"
51	ph10	208	pages. There is a syntax summary in the
52			.\" HREF
53	ph10	583	\fBpcresyntax\fP
54	ph10	208	.\"
55			page.
56	nigel	75	.P
57	nigel	63	Some features of PCRE can be included, excluded, or changed when the library is
58			built. The
59			.\" HREF
60	ph10	583	\fBpcre_config()\fP
61	nigel	63	.\"
62			function makes it possible for a client to discover which features are
63	nigel	75	available. The features themselves are described in the
64			.\" HREF
65			\fBpcrebuild\fP
66			.\"
67			page. Documentation about building PCRE for various operating systems can be
68	ph10	456	found in the \fBREADME\fP and \fBNON-UNIX-USE\fP files in the source
69			distribution.
70	nigel	77	.P
71			The library contains a number of undocumented internal functions and data
72			tables that are used by more than one of the exported external functions, but
73			which are not intended for use by external callers. Their names all begin with
74	nigel	83	"_pcre_", which hopefully will not provoke any name clashes. In some
75			environments, it is possible to control which external symbols are exported
76			when a shared library is built, and in these cases the undocumented symbols are
77			not exported.
78	nigel	75	.
79			.
80			.SH "USER DOCUMENTATION"
81	nigel	63	.rs
82			.sp
83	nigel	75	The user documentation for PCRE comprises a number of different sections. In
84			the "man" format, each of these is a separate "man page". In the HTML format,
85			each is a separate page, linked from the index page. In the plain text format,
86	ph10	429	all the sections, except the \fBpcredemo\fP section, are concatenated, for ease
87			of searching. The sections are as follows:
88	nigel	75	.sp
89	nigel	63	pcre this document
90	ph10	153	pcre-config show PCRE installation configuration information
91	nigel	77	pcreapi details of PCRE's native C API
92	nigel	63	pcrebuild options for building PCRE
93			pcrecallout details of the callout feature
94			pcrecompat discussion of Perl compatibility
95	nigel	77	pcrecpp details of the C++ wrapper
96	ph10	429	pcredemo a demonstration C program that uses PCRE
97	nigel	75	pcregrep description of the \fBpcregrep\fP command
98	ph10	678	pcrejit discussion of the just-in-time optimization support
99			pcrelimits details of size and other limits
100	nigel	77	pcrematching discussion of the two matching algorithms
101	nigel	75	pcrepartial details of the partial matching facility
102			.\" JOIN
103	nigel	63	pcrepattern syntax and semantics of supported
104			regular expressions
105			pcreperform discussion of performance issues
106	nigel	77	pcreposix the POSIX-compatible C API
107	nigel	75	pcreprecompile details of saving and re-using precompiled patterns
108	ph10	429	pcresample discussion of the pcredemo program
109	nigel	91	pcrestack discussion of stack usage
110	ph10	456	pcresyntax quick syntax reference
111	nigel	75	pcretest description of the \fBpcretest\fP testing command
112	ph10	678	pcreunicode discussion of Unicode and UTF-8 support
113	nigel	75	.sp
114	nigel	63	In addition, in the "man" and HTML formats, there is a short page for each
115	nigel	77	C library function, listing its arguments and results.
116	nigel	75	.
117			.
118	nigel	41	.SH AUTHOR
119	nigel	63	.rs
120			.sp
121	ph10	99	.nf
122	nigel	77	Philip Hazel
123	ph10	99	University Computing Service
124	nigel	93	Cambridge CB2 3QH, England.
125	ph10	99	.fi
126	nigel	77	.P
127			Putting an actual email address here seems to have been a spam magnet, so I've
128	ph10	153	taken it away. If you want to email me, use my two initials, followed by the
129			two digits 10, at the domain cam.ac.uk.
130	ph10	99	.
131			.
132			.SH REVISION
133			.rs
134	nigel	75	.sp
135	ph10	99	.nf
136	ph10	678	Last updated: 24 August 2011
137	ph10	598	Copyright (c) 1997-2011 University of Cambridge.
138	ph10	99	.fi
Name	Value
svn:eol-style	native
svn:keywords	"Author Date Id Revision Url"