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revision 172 by ph10, Tue Jun 5 10:40:13 2007 UTC revision 392 by ph10, Tue Mar 17 21:30:30 2009 UTC
# Line 62  trying to optimize the performance of a Line 62  trying to optimize the performance of a
62  <br><a name="SEC2" href="#TOC1">MISSING CALLOUTS</a><br>  <br><a name="SEC2" href="#TOC1">MISSING CALLOUTS</a><br>
63  <P>  <P>
64  You should be aware that, because of optimizations in the way PCRE matches  You should be aware that, because of optimizations in the way PCRE matches
65  patterns, callouts sometimes do not happen. For example, if the pattern is  patterns by default, callouts sometimes do not happen. For example, if the
66    pattern is
67  <pre>  <pre>
68    ab(?C4)cd    ab(?C4)cd
69  </pre>  </pre>
# Line 71  string is "abyz", the lack of "d" means Line 72  string is "abyz", the lack of "d" means
72  the callout is never reached. However, with "abyd", though the result is still  the callout is never reached. However, with "abyd", though the result is still
73  no match, the callout is obeyed.  no match, the callout is obeyed.
74  </P>  </P>
75    <P>
76    You can disable these optimizations by passing the PCRE_NO_START_OPTIMIZE
77    option to <b>pcre_exec()</b> or <b>pcre_dfa_exec()</b>. This slows down the
78    matching process, but does ensure that callouts such as the example above are
79    obeyed.
80    </P>
81  <br><a name="SEC3" href="#TOC1">THE CALLOUT INTERFACE</a><br>  <br><a name="SEC3" href="#TOC1">THE CALLOUT INTERFACE</a><br>
82  <P>  <P>
83  During matching, when PCRE reaches a callout point, the external function  During matching, when PCRE reaches a callout point, the external function
# Line 192  Cambridge CB2 3QH, England. Line 199  Cambridge CB2 3QH, England.
199  </P>  </P>
200  <br><a name="SEC6" href="#TOC1">REVISION</a><br>  <br><a name="SEC6" href="#TOC1">REVISION</a><br>
201  <P>  <P>
202  Last updated: 29 May 2007  Last updated: 15 March 2009
203  <br>  <br>
204  Copyright &copy; 1997-2007 University of Cambridge.  Copyright &copy; 1997-2009 University of Cambridge.
205  <br>  <br>
206  <p>  <p>
207  Return to the <a href="index.html">PCRE index page</a>.  Return to the <a href="index.html">PCRE index page</a>.

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