version 1.1, 2012/02/21 23:05:52
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version 1.1.1.3, 2012/10/09 09:19:18
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Line 21 regular expressions. The differences described here ar
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Line 21 regular expressions. The differences described here ar
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versions 5.10 and above. |
versions 5.10 and above. |
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1. PCRE has only a subset of Perl's UTF-8 and Unicode support. Details of what | 1. PCRE has only a subset of Perl's Unicode support. Details of what it does |
it does have are given in the | have are given in the |
<a href="pcreunicode.html"><b>pcreunicode</b></a> |
<a href="pcreunicode.html"><b>pcreunicode</b></a> |
page. |
page. |
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Line 107 in the
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Line 107 in the
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page. |
page. |
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11. If (*THEN) is present in a group that is called as a subroutine, its action | 11. If any of the backtracking control verbs are used in an assertion or in a |
is limited to that group, even if the group does not contain any | characters. | subpattern that is called as a subroutine (whether or not recursively), their |
| effect is confined to that subpattern; it does not extend to the surrounding |
| pattern. This is not always the case in Perl. In particular, if (*THEN) is |
| present in a group that is called as a subroutine, its action is limited to |
| that group, even if the group does not contain any | characters. There is one |
| exception to this: the name from a *(MARK), (*PRUNE), or (*THEN) that is |
| encountered in a successful positive assertion <i>is</i> passed back when a |
| match succeeds (compare capturing parentheses in assertions). Note that such |
| subpatterns are processed as anchored at the point where they are tested. |
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12. There are some differences that are concerned with the settings of captured |
12. There are some differences that are concerned with the settings of captured |
Line 129 an error is given at compile time.
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Line 137 an error is given at compile time.
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14. Perl recognizes comments in some places that PCRE does not, for example, |
14. Perl recognizes comments in some places that PCRE does not, for example, |
between the ( and ? at the start of a subpattern. If the /x modifier is set, |
between the ( and ? at the start of a subpattern. If the /x modifier is set, |
Perl allows whitespace between ( and ? but PCRE never does, even if the | Perl allows white space between ( and ? but PCRE never does, even if the |
PCRE_EXTENDED option is set. |
PCRE_EXTENDED option is set. |
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Line 181 different hosts that have the other endianness. Howeve
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Line 189 different hosts that have the other endianness. Howeve
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optimized data created by the just-in-time compiler. |
optimized data created by the just-in-time compiler. |
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(k) The alternative matching function (<b>pcre_dfa_exec()</b>) matches in a | (k) The alternative matching functions (<b>pcre_dfa_exec()</b> and |
different way and is not Perl-compatible. | <b>pcre16_dfa_exec()</b>) match in a different way and are not Perl-compatible. |
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(l) PCRE recognizes some special sequences such as (*CR) at the start of |
(l) PCRE recognizes some special sequences such as (*CR) at the start of |
Line 203 Cambridge CB2 3QH, England.
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Line 211 Cambridge CB2 3QH, England.
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REVISION |
REVISION |
</b><br> |
</b><br> |
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Last updated: 14 November 2011 | Last updated: 01 June 2012 |
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Copyright © 1997-2011 University of Cambridge. | Copyright © 1997-2012 University of Cambridge. |
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Return to the <a href="index.html">PCRE index page</a>. |
Return to the <a href="index.html">PCRE index page</a>. |