update to pcre 7.9

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@13706 d0543943-73ff-0310-b7d9-9358b9ac24b2
This commit is contained in:
Michael Jerris
2009-06-08 23:51:30 +00:00
parent a1e5add731
commit f7efdaa901
178 changed files with 43560 additions and 11382 deletions

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@@ -18,26 +18,39 @@ man page, in case the conversion went wrong.
<li><a name="TOC3" href="#SEC3">UTF-8 SUPPORT</a>
<li><a name="TOC4" href="#SEC4">UNICODE CHARACTER PROPERTY SUPPORT</a>
<li><a name="TOC5" href="#SEC5">CODE VALUE OF NEWLINE</a>
<li><a name="TOC6" href="#SEC6">BUILDING SHARED AND STATIC LIBRARIES</a>
<li><a name="TOC7" href="#SEC7">POSIX MALLOC USAGE</a>
<li><a name="TOC8" href="#SEC8">HANDLING VERY LARGE PATTERNS</a>
<li><a name="TOC9" href="#SEC9">AVOIDING EXCESSIVE STACK USAGE</a>
<li><a name="TOC10" href="#SEC10">LIMITING PCRE RESOURCE USAGE</a>
<li><a name="TOC11" href="#SEC11">USING EBCDIC CODE</a>
<li><a name="TOC6" href="#SEC6">WHAT \R MATCHES</a>
<li><a name="TOC7" href="#SEC7">BUILDING SHARED AND STATIC LIBRARIES</a>
<li><a name="TOC8" href="#SEC8">POSIX MALLOC USAGE</a>
<li><a name="TOC9" href="#SEC9">HANDLING VERY LARGE PATTERNS</a>
<li><a name="TOC10" href="#SEC10">AVOIDING EXCESSIVE STACK USAGE</a>
<li><a name="TOC11" href="#SEC11">LIMITING PCRE RESOURCE USAGE</a>
<li><a name="TOC12" href="#SEC12">CREATING CHARACTER TABLES AT BUILD TIME</a>
<li><a name="TOC13" href="#SEC13">USING EBCDIC CODE</a>
<li><a name="TOC14" href="#SEC14">PCREGREP OPTIONS FOR COMPRESSED FILE SUPPORT</a>
<li><a name="TOC15" href="#SEC15">PCRETEST OPTION FOR LIBREADLINE SUPPORT</a>
<li><a name="TOC16" href="#SEC16">SEE ALSO</a>
<li><a name="TOC17" href="#SEC17">AUTHOR</a>
<li><a name="TOC18" href="#SEC18">REVISION</a>
</ul>
<br><a name="SEC1" href="#TOC1">PCRE BUILD-TIME OPTIONS</a><br>
<P>
This document describes the optional features of PCRE that can be selected when
the library is compiled. They are all selected, or deselected, by providing
options to the <b>configure</b> script that is run before the <b>make</b>
command. The complete list of options for <b>configure</b> (which includes the
standard ones such as the selection of the installation directory) can be
obtained by running
the library is compiled. It assumes use of the <b>configure</b> script, where
the optional features are selected or deselected by providing options to
<b>configure</b> before running the <b>make</b> command. However, the same
options can be selected in both Unix-like and non-Unix-like environments using
the GUI facility of <b>CMakeSetup</b> if you are using <b>CMake</b> instead of
<b>configure</b> to build PCRE.
</P>
<P>
The complete list of options for <b>configure</b> (which includes the standard
ones such as the selection of the installation directory) can be obtained by
running
<pre>
./configure --help
</pre>
The following sections describe certain options whose names begin with --enable
or --disable. These settings specify changes to the defaults for the
The following sections include descriptions of options whose names begin with
--enable or --disable. These settings specify changes to the defaults for the
<b>configure</b> command. Because of the way that <b>configure</b> works,
--enable and --disable always come in pairs, so the complementary option always
exists as well, but as it specifies the default, it is not described.
@@ -54,7 +67,7 @@ to the <b>configure</b> command.
</P>
<br><a name="SEC3" href="#TOC1">UTF-8 SUPPORT</a><br>
<P>
To build PCRE with support for UTF-8 character strings, add
To build PCRE with support for UTF-8 Unicode character strings, add
<pre>
--enable-utf8
</pre>
@@ -63,6 +76,13 @@ strings as UTF-8. As well as compiling PCRE with this option, you also have
have to set the PCRE_UTF8 option when you call the <b>pcre_compile()</b>
function.
</P>
<P>
If you set --enable-utf8 when compiling in an EBCDIC environment, PCRE expects
its input to be either ASCII or UTF-8 (depending on the runtime option). It is
not possible to support both EBCDIC and UTF-8 codes in the same version of the
library. Consequently, --enable-utf8 and --enable-ebcdic are mutually
exclusive.
</P>
<br><a name="SEC4" href="#TOC1">UNICODE CHARACTER PROPERTY SUPPORT</a><br>
<P>
UTF-8 support allows PCRE to process character values greater than 255 in the
@@ -77,17 +97,17 @@ to the <b>configure</b> command. This implies UTF-8 support, even if you have
not explicitly requested it.
</P>
<P>
Including Unicode property support adds around 90K of tables to the PCRE
library, approximately doubling its size. Only the general category properties
such as <i>Lu</i> and <i>Nd</i> are supported. Details are given in the
Including Unicode property support adds around 30K of tables to the PCRE
library. Only the general category properties such as <i>Lu</i> and <i>Nd</i> are
supported. Details are given in the
<a href="pcrepattern.html"><b>pcrepattern</b></a>
documentation.
</P>
<br><a name="SEC5" href="#TOC1">CODE VALUE OF NEWLINE</a><br>
<P>
By default, PCRE interprets character 10 (linefeed, LF) as indicating the end
By default, PCRE interprets the linefeed (LF) character as indicating the end
of a line. This is the normal newline character on Unix-like systems. You can
compile PCRE to use character 13 (carriage return, CR) instead, by adding
compile PCRE to use carriage return (CR) instead, by adding
<pre>
--enable-newline-is-cr
</pre>
@@ -100,11 +120,34 @@ character sequence CRLF. If you want this, add
<pre>
--enable-newline-is-crlf
</pre>
to the <b>configure</b> command. Whatever line ending convention is selected
when PCRE is built can be overridden when the library functions are called. At
build time it is conventional to use the standard for your operating system.
to the <b>configure</b> command. There is a fourth option, specified by
<pre>
--enable-newline-is-anycrlf
</pre>
which causes PCRE to recognize any of the three sequences CR, LF, or CRLF as
indicating a line ending. Finally, a fifth option, specified by
<pre>
--enable-newline-is-any
</pre>
causes PCRE to recognize any Unicode newline sequence.
</P>
<br><a name="SEC6" href="#TOC1">BUILDING SHARED AND STATIC LIBRARIES</a><br>
<P>
Whatever line ending convention is selected when PCRE is built can be
overridden when the library functions are called. At build time it is
conventional to use the standard for your operating system.
</P>
<br><a name="SEC6" href="#TOC1">WHAT \R MATCHES</a><br>
<P>
By default, the sequence \R in a pattern matches any Unicode newline sequence,
whatever has been selected as the line ending sequence. If you specify
<pre>
--enable-bsr-anycrlf
</pre>
the default is changed so that \R matches only CR, LF, or CRLF. Whatever is
selected when PCRE is built can be overridden when the library functions are
called.
</P>
<br><a name="SEC7" href="#TOC1">BUILDING SHARED AND STATIC LIBRARIES</a><br>
<P>
The PCRE building process uses <b>libtool</b> to build both shared and static
Unix libraries by default. You can suppress one of these by adding one of
@@ -114,7 +157,7 @@ Unix libraries by default. You can suppress one of these by adding one of
</pre>
to the <b>configure</b> command, as required.
</P>
<br><a name="SEC7" href="#TOC1">POSIX MALLOC USAGE</a><br>
<br><a name="SEC8" href="#TOC1">POSIX MALLOC USAGE</a><br>
<P>
When PCRE is called through the POSIX interface (see the
<a href="pcreposix.html"><b>pcreposix</b></a>
@@ -130,7 +173,7 @@ such as
</pre>
to the <b>configure</b> command.
</P>
<br><a name="SEC8" href="#TOC1">HANDLING VERY LARGE PATTERNS</a><br>
<br><a name="SEC9" href="#TOC1">HANDLING VERY LARGE PATTERNS</a><br>
<P>
Within a compiled pattern, offset values are used to point from one part to
another (for example, from an opening parenthesis to an alternation
@@ -146,12 +189,7 @@ to the <b>configure</b> command. The value given must be 2, 3, or 4. Using
longer offsets slows down the operation of PCRE because it has to load
additional bytes when handling them.
</P>
<P>
If you build PCRE with an increased link size, test 2 (and test 5 if you are
using UTF-8) will fail. Part of the output of these tests is a representation
of the compiled pattern, and this changes with the link size.
</P>
<br><a name="SEC9" href="#TOC1">AVOIDING EXCESSIVE STACK USAGE</a><br>
<br><a name="SEC10" href="#TOC1">AVOIDING EXCESSIVE STACK USAGE</a><br>
<P>
When matching with the <b>pcre_exec()</b> function, PCRE implements backtracking
by making recursive calls to an internal function called <b>match()</b>. In
@@ -169,15 +207,20 @@ build a version of PCRE that works this way, add
</pre>
to the <b>configure</b> command. With this configuration, PCRE will use the
<b>pcre_stack_malloc</b> and <b>pcre_stack_free</b> variables to call memory
management functions. Separate functions are provided because the usage is very
predictable: the block sizes requested are always the same, and the blocks are
always freed in reverse order. A calling program might be able to implement
optimized functions that perform better than the standard <b>malloc()</b> and
<b>free()</b> functions. PCRE runs noticeably more slowly when built in this
way. This option affects only the <b>pcre_exec()</b> function; it is not
relevant for the the <b>pcre_dfa_exec()</b> function.
management functions. By default these point to <b>malloc()</b> and
<b>free()</b>, but you can replace the pointers so that your own functions are
used.
</P>
<br><a name="SEC10" href="#TOC1">LIMITING PCRE RESOURCE USAGE</a><br>
<P>
Separate functions are provided rather than using <b>pcre_malloc</b> and
<b>pcre_free</b> because the usage is very predictable: the block sizes
requested are always the same, and the blocks are always freed in reverse
order. A calling program might be able to implement optimized functions that
perform better than <b>malloc()</b> and <b>free()</b>. PCRE runs noticeably more
slowly when built in this way. This option affects only the <b>pcre_exec()</b>
function; it is not relevant for the the <b>pcre_dfa_exec()</b> function.
</P>
<br><a name="SEC11" href="#TOC1">LIMITING PCRE RESOURCE USAGE</a><br>
<P>
Internally, PCRE has a function called <b>match()</b>, which it calls repeatedly
(sometimes recursively) when matching a pattern with the <b>pcre_exec()</b>
@@ -206,20 +249,100 @@ constraints. However, you can set a lower limit by adding, for example,
</pre>
to the <b>configure</b> command. This value can also be overridden at run time.
</P>
<br><a name="SEC11" href="#TOC1">USING EBCDIC CODE</a><br>
<br><a name="SEC12" href="#TOC1">CREATING CHARACTER TABLES AT BUILD TIME</a><br>
<P>
PCRE uses fixed tables for processing characters whose code values are less
than 256. By default, PCRE is built with a set of tables that are distributed
in the file <i>pcre_chartables.c.dist</i>. These tables are for ASCII codes
only. If you add
<pre>
--enable-rebuild-chartables
</pre>
to the <b>configure</b> command, the distributed tables are no longer used.
Instead, a program called <b>dftables</b> is compiled and run. This outputs the
source for new set of tables, created in the default locale of your C runtime
system. (This method of replacing the tables does not work if you are cross
compiling, because <b>dftables</b> is run on the local host. If you need to
create alternative tables when cross compiling, you will have to do so "by
hand".)
</P>
<br><a name="SEC13" href="#TOC1">USING EBCDIC CODE</a><br>
<P>
PCRE assumes by default that it will run in an environment where the character
code is ASCII (or Unicode, which is a superset of ASCII). PCRE can, however, be
compiled to run in an EBCDIC environment by adding
code is ASCII (or Unicode, which is a superset of ASCII). This is the case for
most computer operating systems. PCRE can, however, be compiled to run in an
EBCDIC environment by adding
<pre>
--enable-ebcdic
</pre>
to the <b>configure</b> command.
to the <b>configure</b> command. This setting implies
--enable-rebuild-chartables. You should only use it if you know that you are in
an EBCDIC environment (for example, an IBM mainframe operating system). The
--enable-ebcdic option is incompatible with --enable-utf8.
</P>
<br><a name="SEC14" href="#TOC1">PCREGREP OPTIONS FOR COMPRESSED FILE SUPPORT</a><br>
<P>
By default, <b>pcregrep</b> reads all files as plain text. You can build it so
that it recognizes files whose names end in <b>.gz</b> or <b>.bz2</b>, and reads
them with <b>libz</b> or <b>libbz2</b>, respectively, by adding one or both of
<pre>
--enable-pcregrep-libz
--enable-pcregrep-libbz2
</pre>
to the <b>configure</b> command. These options naturally require that the
relevant libraries are installed on your system. Configuration will fail if
they are not.
</P>
<br><a name="SEC15" href="#TOC1">PCRETEST OPTION FOR LIBREADLINE SUPPORT</a><br>
<P>
If you add
<pre>
--enable-pcretest-libreadline
</pre>
to the <b>configure</b> command, <b>pcretest</b> is linked with the
<b>libreadline</b> library, and when its input is from a terminal, it reads it
using the <b>readline()</b> function. This provides line-editing and history
facilities. Note that <b>libreadline</b> is GPL-licenced, so if you distribute a
binary of <b>pcretest</b> linked in this way, there may be licensing issues.
</P>
<P>
Last updated: 06 June 2006
Setting this option causes the <b>-lreadline</b> option to be added to the
<b>pcretest</b> build. In many operating environments with a sytem-installed
<b>libreadline</b> this is sufficient. However, in some environments (e.g.
if an unmodified distribution version of readline is in use), some extra
configuration may be necessary. The INSTALL file for <b>libreadline</b> says
this:
<pre>
"Readline uses the termcap functions, but does not link with the
termcap or curses library itself, allowing applications which link
with readline the to choose an appropriate library."
</pre>
If your environment has not been set up so that an appropriate library is
automatically included, you may need to add something like
<pre>
LIBS="-ncurses"
</pre>
immediately before the <b>configure</b> command.
</P>
<br><a name="SEC16" href="#TOC1">SEE ALSO</a><br>
<P>
<b>pcreapi</b>(3), <b>pcre_config</b>(3).
</P>
<br><a name="SEC17" href="#TOC1">AUTHOR</a><br>
<P>
Philip Hazel
<br>
University Computing Service
<br>
Cambridge CB2 3QH, England.
<br>
</P>
<br><a name="SEC18" href="#TOC1">REVISION</a><br>
<P>
Last updated: 17 March 2009
<br>
Copyright &copy; 1997-2009 University of Cambridge.
<br>
Copyright &copy; 1997-2006 University of Cambridge.
<p>
Return to the <a href="index.html">PCRE index page</a>.
</p>