version 1.1.1.2, 2012/02/21 23:50:25
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version 1.1.1.3, 2013/07/22 08:25:57
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Line 77 that PCRE cannot otherwise handle.
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Line 77 that PCRE cannot otherwise handle.
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STACK USAGE AT RUN TIME |
STACK USAGE AT RUN TIME |
</b><br> |
</b><br> |
<P> |
<P> |
When <b>pcre_exec()</b> or <b>pcre16_exec()</b> is used for matching, certain | When <b>pcre_exec()</b> or <b>pcre[16|32]_exec()</b> is used for matching, certain |
kinds of pattern can cause it to use large amounts of the process stack. In |
kinds of pattern can cause it to use large amounts of the process stack. In |
some environments the default process stack is quite small, and if it runs out |
some environments the default process stack is quite small, and if it runs out |
the result is often SIGSEGV. This issue is probably the most frequently raised |
the result is often SIGSEGV. This issue is probably the most frequently raised |
Line 99 contains a few observations about PCRE.
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Line 99 contains a few observations about PCRE.
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</P> |
</P> |
<P> |
<P> |
Using Unicode character properties (the \p, \P, and \X escapes) is slow, |
Using Unicode character properties (the \p, \P, and \X escapes) is slow, |
because PCRE has to scan a structure that contains data for over fifteen | because PCRE has to use a multi-stage table lookup whenever it needs a |
thousand characters whenever it needs a character's property. If you can find | character's property. If you can find an alternative pattern that does not use |
an alternative pattern that does not use character properties, it will probably | character properties, it will probably be faster. |
be faster. | |
</P> |
</P> |
<P> |
<P> |
By default, the escape sequences \b, \d, \s, and \w, and the POSIX |
By default, the escape sequences \b, \d, \s, and \w, and the POSIX |
Line 187 Cambridge CB2 3QH, England.
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Line 186 Cambridge CB2 3QH, England.
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REVISION |
REVISION |
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<P> |
Last updated: 09 January 2012 | Last updated: 25 August 2012 |
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Copyright © 1997-2012 University of Cambridge. |
Copyright © 1997-2012 University of Cambridge. |
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