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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@@ -17,6 +17,8 @@ man page, in case the conversion went wrong.
<li><a name="TOC2" href="#SEC2">MISSING CALLOUTS</a>
<li><a name="TOC3" href="#SEC3">THE CALLOUT INTERFACE</a>
<li><a name="TOC4" href="#SEC4">RETURN VALUES</a>
<li><a name="TOC5" href="#SEC5">AUTHOR</a>
<li><a name="TOC6" href="#SEC6">REVISION</a>
</ul>
<br><a name="SEC1" href="#TOC1">PCRE CALLOUTS</a><br>
<P>
@@ -35,7 +37,7 @@ function is to be called. Different callout points can be identified by putting
a number less than 256 after the letter C. The default value is zero.
For example, this pattern has two callout points:
<pre>
(?C1)\deabc(?C2)def
(?C1)abc(?C2)def
</pre>
If the PCRE_AUTO_CALLOUT option bit is set when <b>pcre_compile()</b> is called,
PCRE automatically inserts callouts, all with number 255, before each item in
@@ -60,7 +62,8 @@ trying to optimize the performance of a particular pattern.
<br><a name="SEC2" href="#TOC1">MISSING CALLOUTS</a><br>
<P>
You should be aware that, because of optimizations in the way PCRE matches
patterns, callouts sometimes do not happen. For example, if the pattern is
patterns by default, callouts sometimes do not happen. For example, if the
pattern is
<pre>
ab(?C4)cd
</pre>
@@ -69,6 +72,12 @@ string is "abyz", the lack of "d" means that matching doesn't ever start, and
the callout is never reached. However, with "abyd", though the result is still
no match, the callout is obeyed.
</P>
<P>
You can disable these optimizations by passing the PCRE_NO_START_OPTIMIZE
option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>. This slows down the
matching process, but does ensure that callouts such as the example above are
obeyed.
</P>
<br><a name="SEC3" href="#TOC1">THE CALLOUT INTERFACE</a><br>
<P>
During matching, when PCRE reaches a callout point, the external function
@@ -113,10 +122,12 @@ The <i>subject</i> and <i>subject_length</i> fields contain copies of the values
that were passed to <b>pcre_exec()</b>.
</P>
<P>
The <i>start_match</i> field contains the offset within the subject at which the
current match attempt started. If the pattern is not anchored, the callout
function may be called several times from the same point in the pattern for
different starting points in the subject.
The <i>start_match</i> field normally contains the offset within the subject at
which the current match attempt started. However, if the escape sequence \K
has been encountered, this value is changed to reflect the modified starting
point. If the pattern is not anchored, the callout function may be called
several times from the same point in the pattern for different starting points
in the subject.
</P>
<P>
The <i>current_position</i> field contains the offset within the subject of the
@@ -177,10 +188,21 @@ values. In particular, PCRE_ERROR_NOMATCH forces a standard "no match" failure.
The error number PCRE_ERROR_CALLOUT is reserved for use by callout functions;
it will never be used by PCRE itself.
</P>
<br><a name="SEC5" href="#TOC1">AUTHOR</a><br>
<P>
Last updated: 28 February 2005
Philip Hazel
<br>
University Computing Service
<br>
Cambridge CB2 3QH, England.
<br>
</P>
<br><a name="SEC6" href="#TOC1">REVISION</a><br>
<P>
Last updated: 15 March 2009
<br>
Copyright &copy; 1997-2009 University of Cambridge.
<br>
Copyright &copy; 1997-2005 University of Cambridge.
<p>
Return to the <a href="index.html">PCRE index page</a>.
</p>