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revision 457 by ph10, Sat Oct 3 16:24:08 2009 UTC revision 531 by ph10, Tue Jun 1 13:53:26 2010 UTC
# Line 132  an application that uses PCRE. The heade Line 132  an application that uses PCRE. The heade
132  and PCRE_MINOR to contain the major and minor release numbers for the library.  and PCRE_MINOR to contain the major and minor release numbers for the library.
133  Applications can use these to include support for different releases of PCRE.  Applications can use these to include support for different releases of PCRE.
134  .P  .P
135    In a Windows environment, if you want to statically link an application program
136    against a non-dll \fBpcre.a\fP file, you must define PCRE_STATIC before
137    including \fBpcre.h\fP or \fBpcrecpp.h\fP, because otherwise the
138    \fBpcre_malloc()\fP and \fBpcre_free()\fP exported functions will be declared
139    \fB__declspec(dllimport)\fP, with unwanted results.
140    .P
141  The functions \fBpcre_compile()\fP, \fBpcre_compile2()\fP, \fBpcre_study()\fP,  The functions \fBpcre_compile()\fP, \fBpcre_compile2()\fP, \fBpcre_study()\fP,
142  and \fBpcre_exec()\fP are used for compiling and matching regular expressions  and \fBpcre_exec()\fP are used for compiling and matching regular expressions
143  in a Perl-compatible manner. A sample program that demonstrates the simplest  in a Perl-compatible manner. A sample program that demonstrates the simplest
# Line 395  avoiding the use of the stack. Line 401  avoiding the use of the stack.
401  Either of the functions \fBpcre_compile()\fP or \fBpcre_compile2()\fP can be  Either of the functions \fBpcre_compile()\fP or \fBpcre_compile2()\fP can be
402  called to compile a pattern into an internal form. The only difference between  called to compile a pattern into an internal form. The only difference between
403  the two interfaces is that \fBpcre_compile2()\fP has an additional argument,  the two interfaces is that \fBpcre_compile2()\fP has an additional argument,
404  \fIerrorcodeptr\fP, via which a numerical error code can be returned. To avoid  \fIerrorcodeptr\fP, via which a numerical error code can be returned. To avoid
405  too much repetition, we refer just to \fBpcre_compile()\fP below, but the  too much repetition, we refer just to \fBpcre_compile()\fP below, but the
406  information applies equally to \fBpcre_compile2()\fP.  information applies equally to \fBpcre_compile2()\fP.
407  .P  .P
408  The pattern is a C string terminated by a binary zero, and is passed in the  The pattern is a C string terminated by a binary zero, and is passed in the
# Line 421  within the pattern (see the detailed des Line 427  within the pattern (see the detailed des
427  .\"  .\"
428  documentation). For those options that can be different in different parts of  documentation). For those options that can be different in different parts of
429  the pattern, the contents of the \fIoptions\fP argument specifies their  the pattern, the contents of the \fIoptions\fP argument specifies their
430  settings at the start of compilation and execution. The PCRE_ANCHORED,  settings at the start of compilation and execution. The PCRE_ANCHORED,
431  PCRE_BSR_\fIxxx\fP, and PCRE_NEWLINE_\fIxxx\fP options can be set at the time  PCRE_BSR_\fIxxx\fP, and PCRE_NEWLINE_\fIxxx\fP options can be set at the time
432  of matching as well as at compile time.  of matching as well as at compile time.
433  .P  .P
# Line 553  set, any backslash in a pattern that is Line 559  set, any backslash in a pattern that is
559  special meaning causes an error, thus reserving these combinations for future  special meaning causes an error, thus reserving these combinations for future
560  expansion. By default, as in Perl, a backslash followed by a letter with no  expansion. By default, as in Perl, a backslash followed by a letter with no
561  special meaning is treated as a literal. (Perl can, however, be persuaded to  special meaning is treated as a literal. (Perl can, however, be persuaded to
562  give a warning for this.) There are at present no other features controlled by  give an error for this, by running it with the -w option.) There are at present
563  this option. It can also be set by a (?X) option setting within a pattern.  no other features controlled by this option. It can also be set by a (?X)
564    option setting within a pattern.
565  .sp  .sp
566    PCRE_FIRSTLINE    PCRE_FIRSTLINE
567  .sp  .sp
# Line 635  were followed by ?: but named parenthese Line 642  were followed by ?: but named parenthese
642  they acquire numbers in the usual way). There is no equivalent of this option  they acquire numbers in the usual way). There is no equivalent of this option
643  in Perl.  in Perl.
644  .sp  .sp
645      PCRE_UCP
646    .sp
647    This option changes the way PCRE processes \eb, \ed, \es, \ew, and some of the
648    POSIX character classes. By default, only ASCII characters are recognized, but
649    if PCRE_UCP is set, Unicode properties are used instead to classify characters.
650    More details are given in the section on
651    .\" HTML <a href="pcre.html#genericchartypes">
652    .\" </a>
653    generic character types
654    .\"
655    in the
656    .\" HREF
657    \fBpcrepattern\fP
658    .\"
659    page. If you set PCRE_UCP, matching one of the items it affects takes much
660    longer. The option is available only if PCRE has been compiled with Unicode
661    property support.
662    .sp
663    PCRE_UNGREEDY    PCRE_UNGREEDY
664  .sp  .sp
665  This option inverts the "greediness" of the quantifiers so that they are not  This option inverts the "greediness" of the quantifiers so that they are not
# Line 747  out of use. To avoid confusion, they hav Line 772  out of use. To avoid confusion, they hav
772    57  \eg is not followed by a braced, angle-bracketed, or quoted    57  \eg is not followed by a braced, angle-bracketed, or quoted
773          name/number or by a plain number          name/number or by a plain number
774    58  a numbered reference must not be zero    58  a numbered reference must not be zero
775    59  (*VERB) with an argument is not supported    59  an argument is not allowed for (*ACCEPT), (*FAIL), or (*COMMIT)
776    60  (*VERB) not recognized    60  (*VERB) not recognized
777    61  number is too big    61  number is too big
778    62  subpattern name expected    62  subpattern name expected
779    63  digit expected after (?+    63  digit expected after (?+
780    64  ] is an invalid data character in JavaScript compatibility mode    64  ] is an invalid data character in JavaScript compatibility mode
781      65  different names for subpatterns of the same number are not allowed
782      66  (*MARK) must have an argument
783      67  this version of PCRE is not compiled with PCRE_UCP support
784  .sp  .sp
785  The numbers 32 and 10000 in errors 48 and 49 are defaults; different values may  The numbers 32 and 10000 in errors 48 and 49 are defaults; different values may
786  be used if the limits were changed when PCRE was built.  be used if the limits were changed when PCRE was built.
# Line 785  in the section on matching a pattern. Line 813  in the section on matching a pattern.
813  .P  .P
814  If studying the pattern does not produce any useful information,  If studying the pattern does not produce any useful information,
815  \fBpcre_study()\fP returns NULL. In that circumstance, if the calling program  \fBpcre_study()\fP returns NULL. In that circumstance, if the calling program
816  wants to pass any of the other fields to \fBpcre_exec()\fP or  wants to pass any of the other fields to \fBpcre_exec()\fP or
817  \fBpcre_dfa_exec()\fP, it must set up its own \fBpcre_extra\fP block.  \fBpcre_dfa_exec()\fP, it must set up its own \fBpcre_extra\fP block.
818  .P  .P
819  The second argument of \fBpcre_study()\fP contains option bits. At present, no  The second argument of \fBpcre_study()\fP contains option bits. At present, no
# Line 807  This is a typical call to \fBpcre_study\ Line 835  This is a typical call to \fBpcre_study\
835      &error);        /* set to NULL or points to a message */      &error);        /* set to NULL or points to a message */
836  .sp  .sp
837  Studying a pattern does two things: first, a lower bound for the length of  Studying a pattern does two things: first, a lower bound for the length of
838  subject string that is needed to match the pattern is computed. This does not  subject string that is needed to match the pattern is computed. This does not
839  mean that there are any strings of that length that match, but it does  mean that there are any strings of that length that match, but it does
840  guarantee that no shorter strings match. The value is used by  guarantee that no shorter strings match. The value is used by
841  \fBpcre_exec()\fP and \fBpcre_dfa_exec()\fP to avoid wasting time by trying to  \fBpcre_exec()\fP and \fBpcre_dfa_exec()\fP to avoid wasting time by trying to
842  match strings that are shorter than the lower bound. You can find out the value  match strings that are shorter than the lower bound. You can find out the value
843  in a calling program via the \fBpcre_fullinfo()\fP function.  in a calling program via the \fBpcre_fullinfo()\fP function.
844  .P  .P
845  Studying a pattern is also useful for non-anchored patterns that do not have a  Studying a pattern is also useful for non-anchored patterns that do not have a
846  single fixed starting character. A bitmap of possible starting bytes is  single fixed starting character. A bitmap of possible starting bytes is
847  created. This speeds up finding a position in the subject at which to start  created. This speeds up finding a position in the subject at which to start
848  matching.  matching.
849  .  .
850  .  .
# Line 827  matching. Line 855  matching.
855  PCRE handles caseless matching, and determines whether characters are letters,  PCRE handles caseless matching, and determines whether characters are letters,
856  digits, or whatever, by reference to a set of tables, indexed by character  digits, or whatever, by reference to a set of tables, indexed by character
857  value. When running in UTF-8 mode, this applies only to characters with codes  value. When running in UTF-8 mode, this applies only to characters with codes
858  less than 128. Higher-valued codes never match escapes such as \ew or \ed, but  less than 128. By default, higher-valued codes never match escapes such as \ew
859  can be tested with \ep if PCRE is built with Unicode character property  or \ed, but they can be tested with \ep if PCRE is built with Unicode character
860  support. The use of locales with Unicode is discouraged. If you are handling  property support. Alternatively, the PCRE_UCP option can be set at compile
861  characters with codes greater than 128, you should either use UTF-8 and  time; this causes \ew and friends to use Unicode property support instead of
862  Unicode, or use locales, but not try to mix the two.  built-in tables. The use of locales with Unicode is discouraged. If you are
863    handling characters with codes greater than 128, you should either use UTF-8
864    and Unicode, or use locales, but not try to mix the two.
865  .P  .P
866  PCRE contains an internal set of tables that are used when the final argument  PCRE contains an internal set of tables that are used when the final argument
867  of \fBpcre_compile()\fP is NULL. These are sufficient for many applications.  of \fBpcre_compile()\fP is NULL. These are sufficient for many applications.
# Line 1012  entry; both of these return an \fBint\fP Line 1042  entry; both of these return an \fBint\fP
1042  length of the longest name. PCRE_INFO_NAMETABLE returns a pointer to the first  length of the longest name. PCRE_INFO_NAMETABLE returns a pointer to the first
1043  entry of the table (a pointer to \fBchar\fP). The first two bytes of each entry  entry of the table (a pointer to \fBchar\fP). The first two bytes of each entry
1044  are the number of the capturing parenthesis, most significant byte first. The  are the number of the capturing parenthesis, most significant byte first. The
1045  rest of the entry is the corresponding name, zero terminated.  rest of the entry is the corresponding name, zero terminated.
1046  .P  .P
1047  The names are in alphabetical order. Duplicate names may appear if (?| is used  The names are in alphabetical order. Duplicate names may appear if (?| is used
1048  to create multiple groups with the same number, as described in the  to create multiple groups with the same number, as described in the
# Line 1024  in the Line 1054  in the
1054  .\" HREF  .\" HREF
1055  \fBpcrepattern\fP  \fBpcrepattern\fP
1056  .\"  .\"
1057  page. Duplicate names for subpatterns with different numbers are permitted only  page. Duplicate names for subpatterns with different numbers are permitted only
1058  if PCRE_DUPNAMES is set. In all cases of duplicate names, they appear in the  if PCRE_DUPNAMES is set. In all cases of duplicate names, they appear in the
1059  table in the order in which they were found in the pattern. In the absence of  table in the order in which they were found in the pattern. In the absence of
1060  (?| this is the order of increasing number; when (?| is used this is not  (?| this is the order of increasing number; when (?| is used this is not
1061  necessarily the case because later subpatterns may have lower numbers.  necessarily the case because later subpatterns may have lower numbers.
1062  .P  .P
1063  As a simple example of the name/number table, consider the following pattern  As a simple example of the name/number table, consider the following pattern
# Line 1210  fields (not necessarily in this order): Line 1240  fields (not necessarily in this order):
1240    unsigned long int \fImatch_limit_recursion\fP;    unsigned long int \fImatch_limit_recursion\fP;
1241    void *\fIcallout_data\fP;    void *\fIcallout_data\fP;
1242    const unsigned char *\fItables\fP;    const unsigned char *\fItables\fP;
1243      unsigned char **\fImark\fP;
1244  .sp  .sp
1245  The \fIflags\fP field is a bitmap that specifies which of the other fields  The \fIflags\fP field is a bitmap that specifies which of the other fields
1246  are set. The flag bits are:  are set. The flag bits are:
# Line 1219  are set. The flag bits are: Line 1250  are set. The flag bits are:
1250    PCRE_EXTRA_MATCH_LIMIT_RECURSION    PCRE_EXTRA_MATCH_LIMIT_RECURSION
1251    PCRE_EXTRA_CALLOUT_DATA    PCRE_EXTRA_CALLOUT_DATA
1252    PCRE_EXTRA_TABLES    PCRE_EXTRA_TABLES
1253      PCRE_EXTRA_MARK
1254  .sp  .sp
1255  Other flag bits should be set to zero. The \fIstudy_data\fP field is set in the  Other flag bits should be set to zero. The \fIstudy_data\fP field is set in the
1256  \fBpcre_extra\fP block that is returned by \fBpcre_study()\fP, together with  \fBpcre_extra\fP block that is returned by \fBpcre_study()\fP, together with
# Line 1281  called. See the Line 1313  called. See the
1313  \fBpcreprecompile\fP  \fBpcreprecompile\fP
1314  .\"  .\"
1315  documentation for a discussion of saving compiled patterns for later use.  documentation for a discussion of saving compiled patterns for later use.
1316    .P
1317    If PCRE_EXTRA_MARK is set in the \fIflags\fP field, the \fImark\fP field must
1318    be set to point to a \fBchar *\fP variable. If the pattern contains any
1319    backtracking control verbs such as (*MARK:NAME), and the execution ends up with
1320    a name to pass back, a pointer to the name string (zero terminated) is placed
1321    in the variable pointed to by the \fImark\fP field. The names are within the
1322    compiled pattern; if you wish to retain such a name you must copy it before
1323    freeing the memory of a compiled pattern. If there is no name to pass back, the
1324    variable pointed to by the \fImark\fP field set to NULL. For details of the
1325    backtracking control verbs, see the section entitled
1326    .\" HTML <a href="pcrepattern#backtrackcontrol">
1327    .\" </a>
1328    "Backtracking control"
1329    .\"
1330    in the
1331    .\" HREF
1332    \fBpcrepattern\fP
1333    .\"
1334    documentation.
1335    .
1336  .  .
1337  .\" HTML <a name="execoptions"></a>  .\" HTML <a name="execoptions"></a>
1338  .SS "Option bits for \fBpcre_exec()\fP"  .SS "Option bits for \fBpcre_exec()\fP"
# Line 1371  valid, so PCRE searches further into the Line 1423  valid, so PCRE searches further into the
1423  .sp  .sp
1424    PCRE_NOTEMPTY_ATSTART    PCRE_NOTEMPTY_ATSTART
1425  .sp  .sp
1426  This is like PCRE_NOTEMPTY, except that an empty string match that is not at  This is like PCRE_NOTEMPTY, except that an empty string match that is not at
1427  the start of the subject is permitted. If the pattern is anchored, such a match  the start of the subject is permitted. If the pattern is anchored, such a match
1428  can occur only if the pattern contains \eK.  can occur only if the pattern contains \eK.
1429  .P  .P
# Line 1427  PCRE_NO_UTF8_CHECK is set, the effect of Line 1479  PCRE_NO_UTF8_CHECK is set, the effect of
1479  subject, or a value of \fIstartoffset\fP that does not point to the start of a  subject, or a value of \fIstartoffset\fP that does not point to the start of a
1480  UTF-8 character, is undefined. Your program may crash.  UTF-8 character, is undefined. Your program may crash.
1481  .sp  .sp
1482    PCRE_PARTIAL_HARD    PCRE_PARTIAL_HARD
1483    PCRE_PARTIAL_SOFT    PCRE_PARTIAL_SOFT
1484  .sp  .sp
1485  These options turn on the partial matching feature. For backwards  These options turn on the partial matching feature. For backwards
# Line 1591  If a pattern contains back references, b Line 1643  If a pattern contains back references, b
1643  gets a block of memory at the start of matching to use for this purpose. If the  gets a block of memory at the start of matching to use for this purpose. If the
1644  call via \fBpcre_malloc()\fP fails, this error is given. The memory is  call via \fBpcre_malloc()\fP fails, this error is given. The memory is
1645  automatically freed at the end of matching.  automatically freed at the end of matching.
1646    .P
1647    This error is also given if \fBpcre_stack_malloc()\fP fails in
1648    \fBpcre_exec()\fP. This can happen only when PCRE has been compiled with
1649    \fB--disable-stack-for-recursion\fP.
1650  .sp  .sp
1651    PCRE_ERROR_NOSUBSTRING    (-7)    PCRE_ERROR_NOSUBSTRING    (-7)
1652  .sp  .sp
# Line 1634  documentation for details of partial mat Line 1690  documentation for details of partial mat
1690  .sp  .sp
1691  This code is no longer in use. It was formerly returned when the PCRE_PARTIAL  This code is no longer in use. It was formerly returned when the PCRE_PARTIAL
1692  option was used with a compiled pattern containing items that were not  option was used with a compiled pattern containing items that were not
1693  supported for partial matching. From release 8.00 onwards, there are no  supported for partial matching. From release 8.00 onwards, there are no
1694  restrictions on partial matching.  restrictions on partial matching.
1695  .sp  .sp
1696    PCRE_ERROR_INTERNAL       (-14)    PCRE_ERROR_INTERNAL       (-14)
# Line 1898  a compiled pattern, using a matching alg Line 1954  a compiled pattern, using a matching alg
1954  just once, and does not backtrack. This has different characteristics to the  just once, and does not backtrack. This has different characteristics to the
1955  normal algorithm, and is not compatible with Perl. Some of the features of PCRE  normal algorithm, and is not compatible with Perl. Some of the features of PCRE
1956  patterns are not supported. Nevertheless, there are times when this kind of  patterns are not supported. Nevertheless, there are times when this kind of
1957  matching can be useful. For a discussion of the two matching algorithms, and a  matching can be useful. For a discussion of the two matching algorithms, and a
1958  list of features that \fBpcre_dfa_exec()\fP does not support, see the  list of features that \fBpcre_dfa_exec()\fP does not support, see the
1959  .\" HREF  .\" HREF
1960  \fBpcrematching\fP  \fBpcrematching\fP
# Line 1944  and PCRE_DFA_RESTART. All but the last f Line 2000  and PCRE_DFA_RESTART. All but the last f
2000  for \fBpcre_exec()\fP, so their description is not repeated here.  for \fBpcre_exec()\fP, so their description is not repeated here.
2001  .sp  .sp
2002    PCRE_PARTIAL_HARD    PCRE_PARTIAL_HARD
2003    PCRE_PARTIAL_SOFT    PCRE_PARTIAL_SOFT
2004  .sp  .sp
2005  These have the same general effect as they do for \fBpcre_exec()\fP, but the  These have the same general effect as they do for \fBpcre_exec()\fP, but the
2006  details are slightly different. When PCRE_PARTIAL_HARD is set for  details are slightly different. When PCRE_PARTIAL_HARD is set for
# Line 2075  Cambridge CB2 3QH, England. Line 2131  Cambridge CB2 3QH, England.
2131  .rs  .rs
2132  .sp  .sp
2133  .nf  .nf
2134  Last updated: 03 October 2009  Last updated: 01 June 2010
2135  Copyright (c) 1997-2009 University of Cambridge.  Copyright (c) 1997-2010 University of Cambridge.
2136  .fi  .fi

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