|
version 1.1.1.2, 2012/02/21 23:50:25
|
version 1.1.1.4, 2014/06/15 19:46:05
|
|
Line 14 man page, in case the conversion went wrong.
|
Line 14 man page, in case the conversion went wrong.
|
| <br> |
<br> |
| <ul> |
<ul> |
| <li><a name="TOC1" href="#SEC1">INTRODUCTION</a> |
<li><a name="TOC1" href="#SEC1">INTRODUCTION</a> |
| <li><a name="TOC2" href="#SEC2">USER DOCUMENTATION</a> | <li><a name="TOC2" href="#SEC2">SECURITY CONSIDERATIONS</a> |
| <li><a name="TOC3" href="#SEC3">AUTHOR</a> | <li><a name="TOC3" href="#SEC3">USER DOCUMENTATION</a> |
| <li><a name="TOC4" href="#SEC4">REVISION</a> | <li><a name="TOC4" href="#SEC4">AUTHOR</a> |
| | <li><a name="TOC5" href="#SEC5">REVISION</a> |
| </ul> |
</ul> |
| <br><a name="SEC1" href="#TOC1">INTRODUCTION</a><br> |
<br><a name="SEC1" href="#TOC1">INTRODUCTION</a><br> |
| <P> |
<P> |
|
Line 36 built. The majority of the work to make this possible
|
Line 37 built. The majority of the work to make this possible
|
| Herczeg. |
Herczeg. |
| </P> |
</P> |
| <P> |
<P> |
| The two libraries contain identical sets of functions, except that the names in | Starting with release 8.32 it is possible to compile a third separate PCRE |
| the 16-bit library start with <b>pcre16_</b> instead of <b>pcre_</b>. To avoid | library that supports 32-bit character strings (including UTF-32 strings). The |
| over-complication and reduce the documentation maintenance load, most of the | build process allows any combination of the 8-, 16- and 32-bit libraries. The |
| documentation describes the 8-bit library, with the differences for the 16-bit | work to make this possible was done by Christian Persch. |
| library described separately in the | </P> |
| | <P> |
| | The three libraries contain identical sets of functions, except that the names |
| | in the 16-bit library start with <b>pcre16_</b> instead of <b>pcre_</b>, and the |
| | names in the 32-bit library start with <b>pcre32_</b> instead of <b>pcre_</b>. To |
| | avoid over-complication and reduce the documentation maintenance load, most of |
| | the documentation describes the 8-bit library, with the differences for the |
| | 16-bit and 32-bit libraries described separately in the |
| <a href="pcre16.html"><b>pcre16</b></a> |
<a href="pcre16.html"><b>pcre16</b></a> |
| page. References to functions or structures of the form <i>pcre[16]_xxx</i> | and |
| should be read as meaning "<i>pcre_xxx</i> when using the 8-bit library and | <a href="pcre32.html"><b>pcre32</b></a> |
| <i>pcre16_xxx</i> when using the 16-bit library". | pages. References to functions or structures of the form <i>pcre[16|32]_xxx</i> |
| | should be read as meaning "<i>pcre_xxx</i> when using the 8-bit library, |
| | <i>pcre16_xxx</i> when using the 16-bit library, or <i>pcre32_xxx</i> when using |
| | the 32-bit library". |
| </P> |
</P> |
| <P> |
<P> |
| The current implementation of PCRE corresponds approximately with Perl 5.12, |
The current implementation of PCRE corresponds approximately with Perl 5.12, |
| including support for UTF-8/16 encoded strings and Unicode general category | including support for UTF-8/16/32 encoded strings and Unicode general category |
| properties. However, UTF-8/16 and Unicode support has to be explicitly enabled; | properties. However, UTF-8/16/32 and Unicode support has to be explicitly |
| it is not the default. The Unicode tables correspond to Unicode release 6.0.0. | enabled; it is not the default. The Unicode tables correspond to Unicode |
| | release 6.3.0. |
| </P> |
</P> |
| <P> |
<P> |
| In addition to the Perl-compatible matching function, PCRE contains an |
In addition to the Perl-compatible matching function, PCRE contains an |
|
Line 88 function makes it possible for a client to discover wh
|
Line 100 function makes it possible for a client to discover wh
|
| available. The features themselves are described in the |
available. The features themselves are described in the |
| <a href="pcrebuild.html"><b>pcrebuild</b></a> |
<a href="pcrebuild.html"><b>pcrebuild</b></a> |
| page. Documentation about building PCRE for various operating systems can be |
page. Documentation about building PCRE for various operating systems can be |
| found in the <b>README</b> and <b>NON-UNIX-USE</b> files in the source | found in the |
| distribution. | <a href="README.txt"><b>README</b></a> |
| | and |
| | <a href="NON-AUTOTOOLS-BUILD.txt"><b>NON-AUTOTOOLS_BUILD</b></a> |
| | files in the source distribution. |
| </P> |
</P> |
| <P> |
<P> |
| The libraries contains a number of undocumented internal functions and data |
The libraries contains a number of undocumented internal functions and data |
| tables that are used by more than one of the exported external functions, but |
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 |
which are not intended for use by external callers. Their names all begin with |
| "_pcre_" or "_pcre16_", which hopefully will not provoke any name clashes. In | "_pcre_" or "_pcre16_" or "_pcre32_", which hopefully will not provoke any name |
| some environments, it is possible to control which external symbols are | clashes. In some environments, it is possible to control which external symbols |
| exported when a shared library is built, and in these cases the undocumented | are exported when a shared library is built, and in these cases the |
| symbols are not exported. | undocumented symbols are not exported. |
| </P> |
</P> |
| <br><a name="SEC2" href="#TOC1">USER DOCUMENTATION</a><br> | <br><a name="SEC2" href="#TOC1">SECURITY CONSIDERATIONS</a><br> |
| <P> |
<P> |
| |
If you are using PCRE in a non-UTF application that permits users to supply |
| |
arbitrary patterns for compilation, you should be aware of a feature that |
| |
allows users to turn on UTF support from within a pattern, provided that PCRE |
| |
was built with UTF support. For example, an 8-bit pattern that begins with |
| |
"(*UTF8)" or "(*UTF)" turns on UTF-8 mode, which interprets patterns and |
| |
subjects as strings of UTF-8 characters instead of individual 8-bit characters. |
| |
This causes both the pattern and any data against which it is matched to be |
| |
checked for UTF-8 validity. If the data string is very long, such a check might |
| |
use sufficiently many resources as to cause your application to lose |
| |
performance. |
| |
</P> |
| |
<P> |
| |
One way of guarding against this possibility is to use the |
| |
<b>pcre_fullinfo()</b> function to check the compiled pattern's options for UTF. |
| |
Alternatively, from release 8.33, you can set the PCRE_NEVER_UTF option at |
| |
compile time. This causes an compile time error if a pattern contains a |
| |
UTF-setting sequence. |
| |
</P> |
| |
<P> |
| |
If your application is one that supports UTF, be aware that validity checking |
| |
can take time. If the same data string is to be matched many times, you can use |
| |
the PCRE_NO_UTF[8|16|32]_CHECK option for the second and subsequent matches to |
| |
save redundant checks. |
| |
</P> |
| |
<P> |
| |
Another way that performance can be hit is by running a pattern that has a very |
| |
large search tree against a string that will never match. Nested unlimited |
| |
repeats in a pattern are a common example. PCRE provides some protection |
| |
against this: see the PCRE_EXTRA_MATCH_LIMIT feature in the |
| |
<a href="pcreapi.html"><b>pcreapi</b></a> |
| |
page. |
| |
</P> |
| |
<br><a name="SEC3" href="#TOC1">USER DOCUMENTATION</a><br> |
| |
<P> |
| The user documentation for PCRE comprises a number of different sections. In |
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, |
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, |
each is a separate page, linked from the index page. In the plain text format, |
|
Line 109 all the sections, except the <b>pcredemo</b> section,
|
Line 158 all the sections, except the <b>pcredemo</b> section,
|
| of searching. The sections are as follows: |
of searching. The sections are as follows: |
| <pre> |
<pre> |
| pcre this document |
pcre this document |
| pcre16 details of the 16-bit library |
|
| pcre-config show PCRE installation configuration information |
pcre-config show PCRE installation configuration information |
| |
pcre16 details of the 16-bit library |
| |
pcre32 details of the 32-bit library |
| pcreapi details of PCRE's native C API |
pcreapi details of PCRE's native C API |
| pcrebuild options for building PCRE | pcrebuild building PCRE |
| pcrecallout details of the callout feature |
pcrecallout details of the callout feature |
| pcrecompat discussion of Perl compatibility |
pcrecompat discussion of Perl compatibility |
| pcrecpp details of the C++ wrapper for the 8-bit library |
pcrecpp details of the C++ wrapper for the 8-bit library |
|
Line 130 of searching. The sections are as follows:
|
Line 180 of searching. The sections are as follows:
|
| pcrestack discussion of stack usage |
pcrestack discussion of stack usage |
| pcresyntax quick syntax reference |
pcresyntax quick syntax reference |
| pcretest description of the <b>pcretest</b> testing command |
pcretest description of the <b>pcretest</b> testing command |
| pcreunicode discussion of Unicode and UTF-8/16 support | pcreunicode discussion of Unicode and UTF-8/16/32 support |
| </pre> |
</pre> |
| In addition, in the "man" and HTML formats, there is a short page for each |
In addition, in the "man" and HTML formats, there is a short page for each |
| 8-bit C library function, listing its arguments and results. | C library function, listing its arguments and results. |
| </P> |
</P> |
| <br><a name="SEC3" href="#TOC1">AUTHOR</a><br> | <br><a name="SEC4" href="#TOC1">AUTHOR</a><br> |
| <P> |
<P> |
| Philip Hazel |
Philip Hazel |
| <br> |
<br> |
|
Line 149 Putting an actual email address here seems to have bee
|
Line 199 Putting an actual email address here seems to have bee
|
| taken it away. If you want to email me, use my two initials, followed by the |
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. |
two digits 10, at the domain cam.ac.uk. |
| </P> |
</P> |
| <br><a name="SEC4" href="#TOC1">REVISION</a><br> | <br><a name="SEC5" href="#TOC1">REVISION</a><br> |
| <P> |
<P> |
| Last updated: 10 January 2012 | Last updated: 13 May 2013 |
| <br> |
<br> |
| Copyright © 1997-2012 University of Cambridge. | Copyright © 1997-2013 University of Cambridge. |
| <br> |
<br> |
| <p> |
<p> |
| Return to the <a href="index.html">PCRE index page</a>. |
Return to the <a href="index.html">PCRE index page</a>. |
![[BACK]](/icons/cvsweb/back.gif){kind=icon}
Return to pcre.html CVS log ![[TXT]](/icons/cvsweb/text.gif){kind=icon}
![[DIR]](/icons/cvsweb/dir.gif){kind=icon}
Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / pcre / doc / html