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revision 243 by ph10, Thu Sep 13 09:28:14 2007 UTC revision 385 by ph10, Sun Mar 8 16:56:58 2009 UTC
# Line 140  distribution. The Line 140  distribution. The
140  .\" HREF  .\" HREF
141  \fBpcresample\fP  \fBpcresample\fP
142  .\"  .\"
143  documentation describes how to run it.  documentation describes how to compile and run it.
144  .P  .P
145  A second matching function, \fBpcre_dfa_exec()\fP, which is not  A second matching function, \fBpcre_dfa_exec()\fP, which is not
146  Perl-compatible, is also provided. This uses a different algorithm for the  Perl-compatible, is also provided. This uses a different algorithm for the
# Line 347  documentation. Line 347  documentation.
347  .sp  .sp
348    PCRE_CONFIG_MATCH_LIMIT    PCRE_CONFIG_MATCH_LIMIT
349  .sp  .sp
350  The output is an integer that gives the default limit for the number of  The output is a long integer that gives the default limit for the number of
351  internal matching function calls in a \fBpcre_exec()\fP execution. Further  internal matching function calls in a \fBpcre_exec()\fP execution. Further
352  details are given with \fBpcre_exec()\fP below.  details are given with \fBpcre_exec()\fP below.
353  .sp  .sp
354    PCRE_CONFIG_MATCH_LIMIT_RECURSION    PCRE_CONFIG_MATCH_LIMIT_RECURSION
355  .sp  .sp
356  The output is an integer that gives the default limit for the depth of  The output is a long integer that gives the default limit for the depth of
357  recursion when calling the internal matching function in a \fBpcre_exec()\fP  recursion when calling the internal matching function in a \fBpcre_exec()\fP
358  execution. Further details are given with \fBpcre_exec()\fP below.  execution. Further details are given with \fBpcre_exec()\fP below.
359  .sp  .sp
# Line 549  If this option is set, an unanchored pat Line 549  If this option is set, an unanchored pat
549  the first newline in the subject string, though the matched text may continue  the first newline in the subject string, though the matched text may continue
550  over the newline.  over the newline.
551  .sp  .sp
552      PCRE_JAVASCRIPT_COMPAT
553    .sp
554    If this option is set, PCRE's behaviour is changed in some ways so that it is
555    compatible with JavaScript rather than Perl. The changes are as follows:
556    .P
557    (1) A lone closing square bracket in a pattern causes a compile-time error,
558    because this is illegal in JavaScript (by default it is treated as a data
559    character). Thus, the pattern AB]CD becomes illegal when this option is set.
560    .P
561    (2) At run time, a back reference to an unset subpattern group matches an empty
562    string (by default this causes the current matching alternative to fail). A
563    pattern such as (\e1)(a) succeeds when this option is set (assuming it can find
564    an "a" in the subject), whereas it fails by default, for Perl compatibility.
565    .sp
566    PCRE_MULTILINE    PCRE_MULTILINE
567  .sp  .sp
568  By default, PCRE treats the subject string as consisting of a single line of  By default, PCRE treats the subject string as consisting of a single line of
# Line 672  out of use. To avoid confusion, they hav Line 686  out of use. To avoid confusion, they hav
686     9  nothing to repeat     9  nothing to repeat
687    10  [this code is not in use]    10  [this code is not in use]
688    11  internal error: unexpected repeat    11  internal error: unexpected repeat
689    12  unrecognized character after (?    12  unrecognized character after (? or (?-
690    13  POSIX named classes are supported only within a class    13  POSIX named classes are supported only within a class
691    14  missing )    14  missing )
692    15  reference to non-existent subpattern    15  reference to non-existent subpattern
# Line 680  out of use. To avoid confusion, they hav Line 694  out of use. To avoid confusion, they hav
694    17  unknown option bit(s) set    17  unknown option bit(s) set
695    18  missing ) after comment    18  missing ) after comment
696    19  [this code is not in use]    19  [this code is not in use]
697    20  regular expression too large    20  regular expression is too large
698    21  failed to get memory    21  failed to get memory
699    22  unmatched parentheses    22  unmatched parentheses
700    23  internal error: code overflow    23  internal error: code overflow
# Line 709  out of use. To avoid confusion, they hav Line 723  out of use. To avoid confusion, they hav
723    46  malformed \eP or \ep sequence    46  malformed \eP or \ep sequence
724    47  unknown property name after \eP or \ep    47  unknown property name after \eP or \ep
725    48  subpattern name is too long (maximum 32 characters)    48  subpattern name is too long (maximum 32 characters)
726    49  too many named subpatterns (maximum 10,000)    49  too many named subpatterns (maximum 10000)
727    50  [this code is not in use]    50  [this code is not in use]
728    51  octal value is greater than \e377 (not in UTF-8 mode)    51  octal value is greater than \e377 (not in UTF-8 mode)
729    52  internal error: overran compiling workspace    52  internal error: overran compiling workspace
# Line 717  out of use. To avoid confusion, they hav Line 731  out of use. To avoid confusion, they hav
731    54  DEFINE group contains more than one branch    54  DEFINE group contains more than one branch
732    55  repeating a DEFINE group is not allowed    55  repeating a DEFINE group is not allowed
733    56  inconsistent NEWLINE options    56  inconsistent NEWLINE options
734    57  \eg is not followed by a braced name or an optionally braced    57  \eg is not followed by a braced, angle-bracketed, or quoted
735          non-zero number          name/number or by a plain number
736    58  (?+ or (?- or (?(+ or (?(- must be followed by a non-zero number    58  a numbered reference must not be zero
737      59  (*VERB) with an argument is not supported
738      60  (*VERB) not recognized
739      61  number is too big
740      62  subpattern name expected
741      63  digit expected after (?+
742      64  ] is an invalid data character in JavaScript compatibility mode
743    .sp
744    The numbers 32 and 10000 in errors 48 and 49 are defaults; different values may
745    be used if the limits were changed when PCRE was built.
746  .  .
747  .  .
748  .SH "STUDYING A PATTERN"  .SH "STUDYING A PATTERN"
# Line 923  explicit match is either a literal CR or Line 946  explicit match is either a literal CR or
946  .sp  .sp
947    PCRE_INFO_JCHANGED    PCRE_INFO_JCHANGED
948  .sp  .sp
949  Return 1 if the (?J) option setting is used in the pattern, otherwise 0. The  Return 1 if the (?J) or (?-J) option setting is used in the pattern, otherwise
950  fourth argument should point to an \fBint\fP variable. The (?J) internal option  0. The fourth argument should point to an \fBint\fP variable. (?J) and
951  setting changes the local PCRE_DUPNAMES option.  (?-J) set and unset the local PCRE_DUPNAMES option, respectively.
952  .sp  .sp
953    PCRE_INFO_LASTLITERAL    PCRE_INFO_LASTLITERAL
954  .sp  .sp
# Line 1348  documentation. Line 1371  documentation.
1371  .rs  .rs
1372  .sp  .sp
1373  The subject string is passed to \fBpcre_exec()\fP as a pointer in  The subject string is passed to \fBpcre_exec()\fP as a pointer in
1374  \fIsubject\fP, a length in \fIlength\fP, and a starting byte offset in  \fIsubject\fP, a length (in bytes) in \fIlength\fP, and a starting byte offset
1375  \fIstartoffset\fP. In UTF-8 mode, the byte offset must point to the start of a  in \fIstartoffset\fP. In UTF-8 mode, the byte offset must point to the start of
1376  UTF-8 character. Unlike the pattern string, the subject may contain binary zero  a UTF-8 character. Unlike the pattern string, the subject may contain binary
1377  bytes. When the starting offset is zero, the search for a match starts at the  zero bytes. When the starting offset is zero, the search for a match starts at
1378  beginning of the subject, and this is by far the most common case.  the beginning of the subject, and this is by far the most common case.
1379  .P  .P
1380  A non-zero starting offset is useful when searching for another match in the  A non-zero starting offset is useful when searching for another match in the
1381  same subject by calling \fBpcre_exec()\fP again after a previous success.  same subject by calling \fBpcre_exec()\fP again after a previous success.
# Line 1386  pattern. Following the usage in Jeffrey Line 1409  pattern. Following the usage in Jeffrey
1409  a fragment of a pattern that picks out a substring. PCRE supports several other  a fragment of a pattern that picks out a substring. PCRE supports several other
1410  kinds of parenthesized subpattern that do not cause substrings to be captured.  kinds of parenthesized subpattern that do not cause substrings to be captured.
1411  .P  .P
1412  Captured substrings are returned to the caller via a vector of integer offsets  Captured substrings are returned to the caller via a vector of integers whose
1413  whose address is passed in \fIovector\fP. The number of elements in the vector  address is passed in \fIovector\fP. The number of elements in the vector is
1414  is passed in \fIovecsize\fP, which must be a non-negative number. \fBNote\fP:  passed in \fIovecsize\fP, which must be a non-negative number. \fBNote\fP: this
1415  this argument is NOT the size of \fIovector\fP in bytes.  argument is NOT the size of \fIovector\fP in bytes.
1416  .P  .P
1417  The first two-thirds of the vector is used to pass back captured substrings,  The first two-thirds of the vector is used to pass back captured substrings,
1418  each substring using a pair of integers. The remaining third of the vector is  each substring using a pair of integers. The remaining third of the vector is
1419  used as workspace by \fBpcre_exec()\fP while matching capturing subpatterns,  used as workspace by \fBpcre_exec()\fP while matching capturing subpatterns,
1420  and is not available for passing back information. The length passed in  and is not available for passing back information. The number passed in
1421  \fIovecsize\fP should always be a multiple of three. If it is not, it is  \fIovecsize\fP should always be a multiple of three. If it is not, it is
1422  rounded down.  rounded down.
1423  .P  .P
1424  When a match is successful, information about captured substrings is returned  When a match is successful, information about captured substrings is returned
1425  in pairs of integers, starting at the beginning of \fIovector\fP, and  in pairs of integers, starting at the beginning of \fIovector\fP, and
1426  continuing up to two-thirds of its length at the most. The first element of a  continuing up to two-thirds of its length at the most. The first element of
1427  pair is set to the offset of the first character in a substring, and the second  each pair is set to the byte offset of the first character in a substring, and
1428  is set to the offset of the first character after the end of a substring. The  the second is set to the byte offset of the first character after the end of a
1429  first pair, \fIovector[0]\fP and \fIovector[1]\fP, identify the portion of the  substring. \fBNote\fP: these values are always byte offsets, even in UTF-8
1430  subject string matched by the entire pattern. The next pair is used for the  mode. They are not character counts.
1431  first capturing subpattern, and so on. The value returned by \fBpcre_exec()\fP  .P
1432  is one more than the highest numbered pair that has been set. For example, if  The first pair of integers, \fIovector[0]\fP and \fIovector[1]\fP, identify the
1433  two substrings have been captured, the returned value is 3. If there are no  portion of the subject string matched by the entire pattern. The next pair is
1434  capturing subpatterns, the return value from a successful match is 1,  used for the first capturing subpattern, and so on. The value returned by
1435  indicating that just the first pair of offsets has been set.  \fBpcre_exec()\fP is one more than the highest numbered pair that has been set.
1436    For example, if two substrings have been captured, the returned value is 3. If
1437    there are no capturing subpatterns, the return value from a successful match is
1438    1, indicating that just the first pair of offsets has been set.
1439  .P  .P
1440  If a capturing subpattern is matched repeatedly, it is the last portion of the  If a capturing subpattern is matched repeatedly, it is the last portion of the
1441  string that it matched that is returned.  string that it matched that is returned.
1442  .P  .P
1443  If the vector is too small to hold all the captured substring offsets, it is  If the vector is too small to hold all the captured substring offsets, it is
1444  used as far as possible (up to two-thirds of its length), and the function  used as far as possible (up to two-thirds of its length), and the function
1445  returns a value of zero. In particular, if the substring offsets are not of  returns a value of zero. If the substring offsets are not of interest,
1446  interest, \fBpcre_exec()\fP may be called with \fIovector\fP passed as NULL and  \fBpcre_exec()\fP may be called with \fIovector\fP passed as NULL and
1447  \fIovecsize\fP as zero. However, if the pattern contains back references and  \fIovecsize\fP as zero. However, if the pattern contains back references and
1448  the \fIovector\fP is not big enough to remember the related substrings, PCRE  the \fIovector\fP is not big enough to remember the related substrings, PCRE
1449  has to get additional memory for use during matching. Thus it is usually  has to get additional memory for use during matching. Thus it is usually
# Line 1703  These functions call \fBpcre_get_stringn Line 1729  These functions call \fBpcre_get_stringn
1729  then call \fBpcre_copy_substring()\fP or \fBpcre_get_substring()\fP, as  then call \fBpcre_copy_substring()\fP or \fBpcre_get_substring()\fP, as
1730  appropriate. \fBNOTE:\fP If PCRE_DUPNAMES is set and there are duplicate names,  appropriate. \fBNOTE:\fP If PCRE_DUPNAMES is set and there are duplicate names,
1731  the behaviour may not be what you want (see the next section).  the behaviour may not be what you want (see the next section).
1732  .  .P
1733    \fBWarning:\fP If the pattern uses the "(?|" feature to set up multiple
1734    subpatterns with the same number, you cannot use names to distinguish them,
1735    because names are not included in the compiled code. The matching process uses
1736    only numbers.
1737  .  .
1738  .SH "DUPLICATE SUBPATTERN NAMES"  .SH "DUPLICATE SUBPATTERN NAMES"
1739  .rs  .rs
# Line 1952  Cambridge CB2 3QH, England. Line 1982  Cambridge CB2 3QH, England.
1982  .rs  .rs
1983  .sp  .sp
1984  .nf  .nf
1985  Last updated: 11 September 2007  Last updated: 08 March 2009
1986  Copyright (c) 1997-2007 University of Cambridge.  Copyright (c) 1997-2009 University of Cambridge.
1987  .fi  .fi

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