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revision 90 by nigel, Sat Feb 24 21:41:21 2007 UTC revision 91 by nigel, Sat Feb 24 21:41:34 2007 UTC
# Line 95  follows: Line 95  follows:
95    pcreposix         the POSIX-compatible C API    pcreposix         the POSIX-compatible C API
96    pcreprecompile    details of saving and re-using precompiled patterns    pcreprecompile    details of saving and re-using precompiled patterns
97    pcresample        discussion of the sample program    pcresample        discussion of the sample program
98      pcrestack         discussion of stack usage
99    pcretest          description of the <b>pcretest</b> testing command    pcretest          description of the <b>pcretest</b> testing command
100  </pre>  </pre>
101  In addition, in the "man" and HTML formats, there is a short page for each  In addition, in the "man" and HTML formats, there is a short page for each
# Line 116  documentation for details). In these cas Line 117  documentation for details). In these cas
117  However, the speed of execution will be slower.  However, the speed of execution will be slower.
118  </P>  </P>
119  <P>  <P>
120  All values in repeating quantifiers must be less than 65536.  All values in repeating quantifiers must be less than 65536. The maximum
121  The maximum number of capturing subpatterns is 65535.  compiled length of subpattern with an explicit repeat count is 30000 bytes. The
122    maximum number of capturing subpatterns is 65535.
123  </P>  </P>
124  <P>  <P>
125  There is no limit to the number of non-capturing subpatterns, but the maximum  There is no limit to the number of non-capturing subpatterns, but the maximum
# Line 125  depth of nesting of all kinds of parenth Line 127  depth of nesting of all kinds of parenth
127  subpatterns, assertions, and other types of subpattern, is 200.  subpatterns, assertions, and other types of subpattern, is 200.
128  </P>  </P>
129  <P>  <P>
130    The maximum length of name for a named subpattern is 32, and the maximum number
131    of named subpatterns is 10000.
132    </P>
133    <P>
134  The maximum length of a subject string is the largest positive number that an  The maximum length of a subject string is the largest positive number that an
135  integer variable can hold. However, when using the traditional matching  integer variable can hold. However, when using the traditional matching
136  function, PCRE uses recursion to handle subpatterns and indefinite repetition.  function, PCRE uses recursion to handle subpatterns and indefinite repetition.
137  This means that the available stack space may limit the size of a subject  This means that the available stack space may limit the size of a subject
138  string that can be processed by certain patterns.  string that can be processed by certain patterns. For a discussion of stack
139    issues, see the
140    <a href="pcrestack.html"><b>pcrestack</b></a>
141    documentation.
142  <a name="utf8support"></a></P>  <a name="utf8support"></a></P>
143  <br><a name="SEC4" href="#TOC1">UTF-8 AND UNICODE PROPERTY SUPPORT</a><br>  <br><a name="SEC4" href="#TOC1">UTF-8 AND UNICODE PROPERTY SUPPORT</a><br>
144  <P>  <P>
# Line 184  may crash. Line 193  may crash.
193  UTF-8 character if the value is greater than 127.  UTF-8 character if the value is greater than 127.
194  </P>  </P>
195  <P>  <P>
196  3. Repeat quantifiers apply to complete UTF-8 characters, not to individual  3. Octal numbers up to \777 are recognized, and match two-byte UTF-8
197    characters for values greater than \177.
198    </P>
199    <P>
200    4. Repeat quantifiers apply to complete UTF-8 characters, not to individual
201  bytes, for example: \x{100}{3}.  bytes, for example: \x{100}{3}.
202  </P>  </P>
203  <P>  <P>
204  4. The dot metacharacter matches one UTF-8 character instead of a single byte.  5. The dot metacharacter matches one UTF-8 character instead of a single byte.
205  </P>  </P>
206  <P>  <P>
207  5. The escape sequence \C can be used to match a single byte in UTF-8 mode,  6. The escape sequence \C can be used to match a single byte in UTF-8 mode,
208  but its use can lead to some strange effects. This facility is not available in  but its use can lead to some strange effects. This facility is not available in
209  the alternative matching function, <b>pcre_dfa_exec()</b>.  the alternative matching function, <b>pcre_dfa_exec()</b>.
210  </P>  </P>
211  <P>  <P>
212  6. The character escapes \b, \B, \d, \D, \s, \S, \w, and \W correctly  7. The character escapes \b, \B, \d, \D, \s, \S, \w, and \W correctly
213  test characters of any code value, but the characters that PCRE recognizes as  test characters of any code value, but the characters that PCRE recognizes as
214  digits, spaces, or word characters remain the same set as before, all with  digits, spaces, or word characters remain the same set as before, all with
215  values less than 256. This remains true even when PCRE includes Unicode  values less than 256. This remains true even when PCRE includes Unicode
# Line 205  cases. If you really want to test for a Line 218  cases. If you really want to test for a
218  must use Unicode property tests such as \p{Nd}.  must use Unicode property tests such as \p{Nd}.
219  </P>  </P>
220  <P>  <P>
221  7. Similarly, characters that match the POSIX named character classes are all  8. Similarly, characters that match the POSIX named character classes are all
222  low-valued characters.  low-valued characters.
223  </P>  </P>
224  <P>  <P>
225  8. Case-insensitive matching applies only to characters whose values are less  9. Case-insensitive matching applies only to characters whose values are less
226  than 128, unless PCRE is built with Unicode property support. Even when Unicode  than 128, unless PCRE is built with Unicode property support. Even when Unicode
227  property support is available, PCRE still uses its own character tables when  property support is available, PCRE still uses its own character tables when
228  checking the case of low-valued characters, so as not to degrade performance.  checking the case of low-valued characters, so as not to degrade performance.
# Line 231  Cambridge CB2 3QG, England. Line 244  Cambridge CB2 3QG, England.
244  Putting an actual email address here seems to have been a spam magnet, so I've  Putting an actual email address here seems to have been a spam magnet, so I've
245  taken it away. If you want to email me, use my initial and surname, separated  taken it away. If you want to email me, use my initial and surname, separated
246  by a dot, at the domain ucs.cam.ac.uk.  by a dot, at the domain ucs.cam.ac.uk.
247  Last updated: 24 January 2006  Last updated: 05 June 2006
248  <br>  <br>
249  Copyright &copy; 1997-2006 University of Cambridge.  Copyright &copy; 1997-2006 University of Cambridge.
250  <p>  <p>
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