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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 92  follows: Line 92  follows:
92    pcreposix         the POSIX-compatible C API    pcreposix         the POSIX-compatible C API
93    pcreprecompile    details of saving and re-using precompiled patterns    pcreprecompile    details of saving and re-using precompiled patterns
94    pcresample        discussion of the sample program    pcresample        discussion of the sample program
95      pcrestack         discussion of stack usage
96    pcretest          description of the \fBpcretest\fP testing command    pcretest          description of the \fBpcretest\fP testing command
97  .sp  .sp
98  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 115  distribution and the Line 116  distribution and the
116  documentation for details). In these cases the limit is substantially larger.  documentation for details). In these cases the limit is substantially larger.
117  However, the speed of execution will be slower.  However, the speed of execution will be slower.
118  .P  .P
119  All values in repeating quantifiers must be less than 65536.  All values in repeating quantifiers must be less than 65536. The maximum
120  The maximum number of capturing subpatterns is 65535.  compiled length of subpattern with an explicit repeat count is 30000 bytes. The
121    maximum number of capturing subpatterns is 65535.
122  .P  .P
123  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
124  depth of nesting of all kinds of parenthesized subpattern, including capturing  depth of nesting of all kinds of parenthesized subpattern, including capturing
125  subpatterns, assertions, and other types of subpattern, is 200.  subpatterns, assertions, and other types of subpattern, is 200.
126  .P  .P
127    The maximum length of name for a named subpattern is 32, and the maximum number
128    of named subpatterns is 10000.
129    .P
130  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
131  integer variable can hold. However, when using the traditional matching  integer variable can hold. However, when using the traditional matching
132  function, PCRE uses recursion to handle subpatterns and indefinite repetition.  function, PCRE uses recursion to handle subpatterns and indefinite repetition.
133  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
134  string that can be processed by certain patterns.  string that can be processed by certain patterns. For a discussion of stack
135    issues, see the
136    .\" HREF
137    \fBpcrestack\fP
138    .\"
139    documentation.
140  .sp  .sp
141  .\" HTML <a name="utf8support"></a>  .\" HTML <a name="utf8support"></a>
142  .  .
# Line 182  may crash. Line 192  may crash.
192  2. An unbraced hexadecimal escape sequence (such as \exb3) matches a two-byte  2. An unbraced hexadecimal escape sequence (such as \exb3) matches a two-byte
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  3. Repeat quantifiers apply to complete UTF-8 characters, not to individual  3. Octal numbers up to \e777 are recognized, and match two-byte UTF-8
196    characters for values greater than \e177.
197    .P
198    4. Repeat quantifiers apply to complete UTF-8 characters, not to individual
199  bytes, for example: \ex{100}{3}.  bytes, for example: \ex{100}{3}.
200  .P  .P
201  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.
202  .P  .P
203  5. The escape sequence \eC can be used to match a single byte in UTF-8 mode,  6. The escape sequence \eC can be used to match a single byte in UTF-8 mode,
204  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
205  the alternative matching function, \fBpcre_dfa_exec()\fP.  the alternative matching function, \fBpcre_dfa_exec()\fP.
206  .P  .P
207  6. The character escapes \eb, \eB, \ed, \eD, \es, \eS, \ew, and \eW correctly  7. The character escapes \eb, \eB, \ed, \eD, \es, \eS, \ew, and \eW correctly
208  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
209  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
210  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 199  property support, because to do otherwis Line 212  property support, because to do otherwis
212  cases. If you really want to test for a wider sense of, say, "digit", you  cases. If you really want to test for a wider sense of, say, "digit", you
213  must use Unicode property tests such as \ep{Nd}.  must use Unicode property tests such as \ep{Nd}.
214  .P  .P
215  7. Similarly, characters that match the POSIX named character classes are all  8. Similarly, characters that match the POSIX named character classes are all
216  low-valued characters.  low-valued characters.
217  .P  .P
218  8. Case-insensitive matching applies only to characters whose values are less  9. Case-insensitive matching applies only to characters whose values are less
219  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
220  property support is available, PCRE still uses its own character tables when  property support is available, PCRE still uses its own character tables when
221  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 226  taken it away. If you want to email me, Line 239  taken it away. If you want to email me,
239  by a dot, at the domain ucs.cam.ac.uk.  by a dot, at the domain ucs.cam.ac.uk.
240  .sp  .sp
241  .in 0  .in 0
242  Last updated: 24 January 2006  Last updated: 05 June 2006
243  .br  .br
244  Copyright (c) 1997-2006 University of Cambridge.  Copyright (c) 1997-2006 University of Cambridge.

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