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revision 336 by ph10, Sat Apr 12 15:59:03 2008 UTC revision 389 by ph10, Sun Mar 15 18:24:05 2009 UTC
# 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 551  over the newline. Line 551  over the newline.
551  .sp  .sp
552    PCRE_JAVASCRIPT_COMPAT    PCRE_JAVASCRIPT_COMPAT
553  .sp  .sp
554  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
555  compatible with JavaScript rather than Perl. The changes are as follows:  compatible with JavaScript rather than Perl. The changes are as follows:
556  .P  .P
557  (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 559  because this is illegal in JavaScript (b
559  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.
560  .P  .P
561  (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
562  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
563  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
564  in the subject), whereas it fails by default, for Perl compatibility.  an "a" in the subject), whereas it fails by default, for Perl compatibility.
565  .sp  .sp
566    PCRE_MULTILINE    PCRE_MULTILINE
567  .sp  .sp
# Line 731  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, angle-bracketed, or quoted    57  \eg is not followed by a braced, angle-bracketed, or quoted
735          name/number or by a plain number          name/number or by a plain number
736    58  a numbered reference must not be zero    58  a numbered reference must not be zero
737    59  (*VERB) with an argument is not supported    59  (*VERB) with an argument is not supported
738    60  (*VERB) not recognized    60  (*VERB) not recognized
# Line 1237  documentation for a discussion of saving Line 1237  documentation for a discussion of saving
1237  .sp  .sp
1238  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
1239  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,
1240  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_UTF8_CHECK and PCRE_PARTIAL.  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_START_OPTIMIZE,
1241    PCRE_NO_UTF8_CHECK and PCRE_PARTIAL.
1242  .sp  .sp
1243    PCRE_ANCHORED    PCRE_ANCHORED
1244  .sp  .sp
# Line 1324  PCRE_NOTEMPTY and PCRE_ANCHORED, and the Line 1325  PCRE_NOTEMPTY and PCRE_ANCHORED, and the
1325  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
1326  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.
1327  .sp  .sp
1328      PCRE_NO_START_OPTIMIZE
1329    .sp
1330    There are a number of optimizations that \fBpcre_exec()\fP uses at the start of
1331    a match, in order to speed up the process. For example, if it is known that a
1332    match must start with a specific character, it searches the subject for that
1333    character, and fails immediately if it cannot find it, without actually running
1334    the main matching function. When callouts are in use, these optimizations can
1335    cause them to be skipped. This option disables the "start-up" optimizations,
1336    causing performance to suffer, but ensuring that the callouts do occur.
1337    .sp
1338    PCRE_NO_UTF8_CHECK    PCRE_NO_UTF8_CHECK
1339  .sp  .sp
1340  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 1382  documentation.
1382  .rs  .rs
1383  .sp  .sp
1384  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
1385  \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
1386  \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
1387  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
1388  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
1389  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.
1390  .P  .P
1391  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
1392  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 1420  pattern. Following the usage in Jeffrey
1420  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
1421  kinds of parenthesized subpattern that do not cause substrings to be captured.  kinds of parenthesized subpattern that do not cause substrings to be captured.
1422  .P  .P
1423  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
1424  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
1425  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
1426  this argument is NOT the size of \fIovector\fP in bytes.  argument is NOT the size of \fIovector\fP in bytes.
1427  .P  .P
1428  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,
1429  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
1430  used as workspace by \fBpcre_exec()\fP while matching capturing subpatterns,  used as workspace by \fBpcre_exec()\fP while matching capturing subpatterns,
1431  and is not available for passing back information. The length passed in  and is not available for passing back information. The number passed in
1432  \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
1433  rounded down.  rounded down.
1434  .P  .P
1435  When a match is successful, information about captured substrings is returned  When a match is successful, information about captured substrings is returned
1436  in pairs of integers, starting at the beginning of \fIovector\fP, and  in pairs of integers, starting at the beginning of \fIovector\fP, and
1437  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
1438  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
1439  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
1440  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
1441  subject string matched by the entire pattern. The next pair is used for the  mode. They are not character counts.
1442  first capturing subpattern, and so on. The value returned by \fBpcre_exec()\fP  .P
1443  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
1444  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
1445  capturing subpatterns, the return value from a successful match is 1,  used for the first capturing subpattern, and so on. The value returned by
1446  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.
1447    For example, if two substrings have been captured, the returned value is 3. If
1448    there are no capturing subpatterns, the return value from a successful match is
1449    1, indicating that just the first pair of offsets has been set.
1450  .P  .P
1451  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
1452  string that it matched that is returned.  string that it matched that is returned.
1453  .P  .P
1454  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
1455  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
1456  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,
1457  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
1458  \fIovecsize\fP as zero. However, if the pattern contains back references and  \fIovecsize\fP as zero. However, if the pattern contains back references and
1459  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
1460  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 1740  These functions call \fBpcre_get_stringn
1740  then call \fBpcre_copy_substring()\fP or \fBpcre_get_substring()\fP, as  then call \fBpcre_copy_substring()\fP or \fBpcre_get_substring()\fP, as
1741  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,
1742  the behaviour may not be what you want (see the next section).  the behaviour may not be what you want (see the next section).
1743  .  .P
1744    \fBWarning:\fP If the pattern uses the "(?|" feature to set up multiple
1745    subpatterns with the same number, you cannot use names to distinguish them,
1746    because names are not included in the compiled code. The matching process uses
1747    only numbers.
1748  .  .
1749  .SH "DUPLICATE SUBPATTERN NAMES"  .SH "DUPLICATE SUBPATTERN NAMES"
1750  .rs  .rs
# Line 1975  Cambridge CB2 3QH, England. Line 1993  Cambridge CB2 3QH, England.
1993  .rs  .rs
1994  .sp  .sp
1995  .nf  .nf
1996  Last updated: 12 April 2008  Last updated: 15 March 2009
1997  Copyright (c) 1997-2008 University of Cambridge.  Copyright (c) 1997-2009 University of Cambridge.
1998  .fi  .fi

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