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revision 336 by ph10, Sat Apr 12 15:59:03 2008 UTC revision 392 by ph10, Tue Mar 17 21:30:30 2009 UTC
# Line 317  properties is available; otherwise it is Line 317  properties is available; otherwise it is
317  .sp  .sp
318  The output is an integer whose value specifies the default character sequence  The output is an integer whose value specifies the default character sequence
319  that is recognized as meaning "newline". The four values that are supported  that is recognized as meaning "newline". The four values that are supported
320  are: 10 for LF, 13 for CR, 3338 for CRLF, -2 for ANYCRLF, and -1 for ANY. The  are: 10 for LF, 13 for CR, 3338 for CRLF, -2 for ANYCRLF, and -1 for ANY.
321  default should normally be the standard sequence for your operating system.  Though they are derived from ASCII, the same values are returned in EBCDIC
322    environments. The default should normally correspond to the standard sequence
323    for your operating system.
324  .sp  .sp
325    PCRE_CONFIG_BSR    PCRE_CONFIG_BSR
326  .sp  .sp
# Line 347  documentation. Line 349  documentation.
349  .sp  .sp
350    PCRE_CONFIG_MATCH_LIMIT    PCRE_CONFIG_MATCH_LIMIT
351  .sp  .sp
352  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
353  internal matching function calls in a \fBpcre_exec()\fP execution. Further  internal matching function calls in a \fBpcre_exec()\fP execution. Further
354  details are given with \fBpcre_exec()\fP below.  details are given with \fBpcre_exec()\fP below.
355  .sp  .sp
356    PCRE_CONFIG_MATCH_LIMIT_RECURSION    PCRE_CONFIG_MATCH_LIMIT_RECURSION
357  .sp  .sp
358  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
359  recursion when calling the internal matching function in a \fBpcre_exec()\fP  recursion when calling the internal matching function in a \fBpcre_exec()\fP
360  execution. Further details are given with \fBpcre_exec()\fP below.  execution. Further details are given with \fBpcre_exec()\fP below.
361  .sp  .sp
# Line 551  over the newline. Line 553  over the newline.
553  .sp  .sp
554    PCRE_JAVASCRIPT_COMPAT    PCRE_JAVASCRIPT_COMPAT
555  .sp  .sp
556  If this option is set, PCRE's behaviour is changed in some ways so that it is  If this option is set, PCRE's behaviour is changed in some ways so that it is
557  compatible with JavaScript rather than Perl. The changes are as follows:  compatible with JavaScript rather than Perl. The changes are as follows:
558  .P  .P
559  (1) A lone closing square bracket in a pattern causes a compile-time error,  (1) A lone closing square bracket in a pattern causes a compile-time error,
# Line 559  because this is illegal in JavaScript (b Line 561  because this is illegal in JavaScript (b
561  character). Thus, the pattern AB]CD becomes illegal when this option is set.  character). Thus, the pattern AB]CD becomes illegal when this option is set.
562  .P  .P
563  (2) At run time, a back reference to an unset subpattern group matches an empty  (2) At run time, a back reference to an unset subpattern group matches an empty
564  string (by default this causes the current matching path to fail). A pattern  string (by default this causes the current matching alternative to fail). A
565  such as (\1)(a) succeeds when this option is set (assuming it can find an "a"  pattern such as (\e1)(a) succeeds when this option is set (assuming it can find
566  in the subject), whereas it fails by default, for Perl compatibility.  an "a" in the subject), whereas it fails by default, for Perl compatibility.
567  .sp  .sp
568    PCRE_MULTILINE    PCRE_MULTILINE
569  .sp  .sp
# Line 731  out of use. To avoid confusion, they hav Line 733  out of use. To avoid confusion, they hav
733    54  DEFINE group contains more than one branch    54  DEFINE group contains more than one branch
734    55  repeating a DEFINE group is not allowed    55  repeating a DEFINE group is not allowed
735    56  inconsistent NEWLINE options    56  inconsistent NEWLINE options
736    57  \eg is not followed by a braced, angle-bracketed, or quoted    57  \eg is not followed by a braced, angle-bracketed, or quoted
737          name/number or by a plain number          name/number or by a plain number
738    58  a numbered reference must not be zero    58  a numbered reference must not be zero
739    59  (*VERB) with an argument is not supported    59  (*VERB) with an argument is not supported
740    60  (*VERB) not recognized    60  (*VERB) not recognized
# Line 1237  documentation for a discussion of saving Line 1239  documentation for a discussion of saving
1239  .sp  .sp
1240  The unused bits of the \fIoptions\fP argument for \fBpcre_exec()\fP must be  The unused bits of the \fIoptions\fP argument for \fBpcre_exec()\fP must be
1241  zero. The only bits that may be set are PCRE_ANCHORED, PCRE_NEWLINE_\fIxxx\fP,  zero. The only bits that may be set are PCRE_ANCHORED, PCRE_NEWLINE_\fIxxx\fP,
1242  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_UTF8_CHECK and PCRE_PARTIAL.  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_START_OPTIMIZE,
1243    PCRE_NO_UTF8_CHECK and PCRE_PARTIAL.
1244  .sp  .sp
1245    PCRE_ANCHORED    PCRE_ANCHORED
1246  .sp  .sp
# Line 1324  PCRE_NOTEMPTY and PCRE_ANCHORED, and the Line 1327  PCRE_NOTEMPTY and PCRE_ANCHORED, and the
1327  starting offset (see below) and trying an ordinary match again. There is some  starting offset (see below) and trying an ordinary match again. There is some
1328  code that demonstrates how to do this in the \fIpcredemo.c\fP sample program.  code that demonstrates how to do this in the \fIpcredemo.c\fP sample program.
1329  .sp  .sp
1330      PCRE_NO_START_OPTIMIZE
1331    .sp
1332    There are a number of optimizations that \fBpcre_exec()\fP uses at the start of
1333    a match, in order to speed up the process. For example, if it is known that a
1334    match must start with a specific character, it searches the subject for that
1335    character, and fails immediately if it cannot find it, without actually running
1336    the main matching function. When callouts are in use, these optimizations can
1337    cause them to be skipped. This option disables the "start-up" optimizations,
1338    causing performance to suffer, but ensuring that the callouts do occur.
1339    .sp
1340    PCRE_NO_UTF8_CHECK    PCRE_NO_UTF8_CHECK
1341  .sp  .sp
1342  When PCRE_UTF8 is set at compile time, the validity of the subject as a UTF-8  When PCRE_UTF8 is set at compile time, the validity of the subject as a UTF-8
# Line 1371  documentation. Line 1384  documentation.
1384  .rs  .rs
1385  .sp  .sp
1386  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
1387  \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
1388  \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
1389  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
1390  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
1391  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.
1392  .P  .P
1393  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
1394  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 1409  pattern. Following the usage in Jeffrey Line 1422  pattern. Following the usage in Jeffrey
1422  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
1423  kinds of parenthesized subpattern that do not cause substrings to be captured.  kinds of parenthesized subpattern that do not cause substrings to be captured.
1424  .P  .P
1425  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
1426  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
1427  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
1428  this argument is NOT the size of \fIovector\fP in bytes.  argument is NOT the size of \fIovector\fP in bytes.
1429  .P  .P
1430  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,
1431  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
1432  used as workspace by \fBpcre_exec()\fP while matching capturing subpatterns,  used as workspace by \fBpcre_exec()\fP while matching capturing subpatterns,
1433  and is not available for passing back information. The length passed in  and is not available for passing back information. The number passed in
1434  \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
1435  rounded down.  rounded down.
1436  .P  .P
1437  When a match is successful, information about captured substrings is returned  When a match is successful, information about captured substrings is returned
1438  in pairs of integers, starting at the beginning of \fIovector\fP, and  in pairs of integers, starting at the beginning of \fIovector\fP, and
1439  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
1440  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
1441  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
1442  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
1443  subject string matched by the entire pattern. The next pair is used for the  mode. They are not character counts.
1444  first capturing subpattern, and so on. The value returned by \fBpcre_exec()\fP  .P
1445  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
1446  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
1447  capturing subpatterns, the return value from a successful match is 1,  used for the first capturing subpattern, and so on. The value returned by
1448  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.
1449    For example, if two substrings have been captured, the returned value is 3. If
1450    there are no capturing subpatterns, the return value from a successful match is
1451    1, indicating that just the first pair of offsets has been set.
1452  .P  .P
1453  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
1454  string that it matched that is returned.  string that it matched that is returned.
1455  .P  .P
1456  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
1457  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
1458  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,
1459  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
1460  \fIovecsize\fP as zero. However, if the pattern contains back references and  \fIovecsize\fP as zero. However, if the pattern contains back references and
1461  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
1462  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 1726  These functions call \fBpcre_get_stringn Line 1742  These functions call \fBpcre_get_stringn
1742  then call \fBpcre_copy_substring()\fP or \fBpcre_get_substring()\fP, as  then call \fBpcre_copy_substring()\fP or \fBpcre_get_substring()\fP, as
1743  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,
1744  the behaviour may not be what you want (see the next section).  the behaviour may not be what you want (see the next section).
1745  .  .P
1746    \fBWarning:\fP If the pattern uses the "(?|" feature to set up multiple
1747    subpatterns with the same number, you cannot use names to distinguish them,
1748    because names are not included in the compiled code. The matching process uses
1749    only numbers.
1750  .  .
1751  .SH "DUPLICATE SUBPATTERN NAMES"  .SH "DUPLICATE SUBPATTERN NAMES"
1752  .rs  .rs
# Line 1975  Cambridge CB2 3QH, England. Line 1995  Cambridge CB2 3QH, England.
1995  .rs  .rs
1996  .sp  .sp
1997  .nf  .nf
1998  Last updated: 12 April 2008  Last updated: 17 March 2009
1999  Copyright (c) 1997-2008 University of Cambridge.  Copyright (c) 1997-2009 University of Cambridge.
2000  .fi  .fi

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