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revision 457 by ph10, Sat Oct 3 16:24:08 2009 UTC revision 691 by ph10, Sun Sep 11 14:31:21 2011 UTC
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1  .TH PCREAPI 3  .TH PCREAPI 3
2  .SH NAME  .SH NAME
3  PCRE - Perl-compatible regular expressions  PCRE - Perl-compatible regular expressions
4  .SH "PCRE NATIVE API"  .SH "PCRE NATIVE API BASIC FUNCTIONS"
5  .rs  .rs
6  .sp  .sp
7  .B #include <pcre.h>  .B #include <pcre.h>
# Line 25  PCRE - Perl-compatible regular expressio Line 25  PCRE - Perl-compatible regular expressio
25  .ti +5n  .ti +5n
26  .B const char **\fIerrptr\fP);  .B const char **\fIerrptr\fP);
27  .PP  .PP
28    .B void pcre_free_study(pcre_extra *\fIextra\fP);
29    .PP
30  .B int pcre_exec(const pcre *\fIcode\fP, "const pcre_extra *\fIextra\fP,"  .B int pcre_exec(const pcre *\fIcode\fP, "const pcre_extra *\fIextra\fP,"
31  .ti +5n  .ti +5n
32  .B "const char *\fIsubject\fP," int \fIlength\fP, int \fIstartoffset\fP,  .B "const char *\fIsubject\fP," int \fIlength\fP, int \fIstartoffset\fP,
33  .ti +5n  .ti +5n
34  .B int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP);  .B int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP);
35    .
36    .
37    .SH "PCRE NATIVE API AUXILIARY FUNCTIONS"
38    .rs
39    .sp
40    .B pcre_jit_stack *pcre_jit_stack_alloc(int \fIstartsize\fP, int \fImaxsize\fP);
41    .PP
42    .B void pcre_jit_stack_free(pcre_jit_stack *\fIstack\fP);
43    .PP
44    .B void pcre_assign_jit_stack(pcre_extra *\fIextra\fP,
45    .ti +5n
46    .B pcre_jit_callback \fIcallback\fP, void *\fIdata\fP);
47  .PP  .PP
48  .B int pcre_dfa_exec(const pcre *\fIcode\fP, "const pcre_extra *\fIextra\fP,"  .B int pcre_dfa_exec(const pcre *\fIcode\fP, "const pcre_extra *\fIextra\fP,"
49  .ti +5n  .ti +5n
# Line 97  PCRE - Perl-compatible regular expressio Line 111  PCRE - Perl-compatible regular expressio
111  .B int pcre_config(int \fIwhat\fP, void *\fIwhere\fP);  .B int pcre_config(int \fIwhat\fP, void *\fIwhere\fP);
112  .PP  .PP
113  .B char *pcre_version(void);  .B char *pcre_version(void);
114  .PP  .
115    .
116    .SH "PCRE NATIVE API INDIRECTED FUNCTIONS"
117    .rs
118    .sp
119  .B void *(*pcre_malloc)(size_t);  .B void *(*pcre_malloc)(size_t);
120  .PP  .PP
121  .B void (*pcre_free)(void *);  .B void (*pcre_free)(void *);
# Line 114  PCRE - Perl-compatible regular expressio Line 132  PCRE - Perl-compatible regular expressio
132  .sp  .sp
133  PCRE has its own native API, which is described in this document. There are  PCRE has its own native API, which is described in this document. There are
134  also some wrapper functions that correspond to the POSIX regular expression  also some wrapper functions that correspond to the POSIX regular expression
135  API. These are described in the  API, but they do not give access to all the functionality. They are described
136    in the
137  .\" HREF  .\" HREF
138  \fBpcreposix\fP  \fBpcreposix\fP
139  .\"  .\"
140  documentation. Both of these APIs define a set of C function calls. A C++  documentation. Both of these APIs define a set of C function calls. A C++
141  wrapper is distributed with PCRE. It is documented in the  wrapper is also distributed with PCRE. It is documented in the
142  .\" HREF  .\" HREF
143  \fBpcrecpp\fP  \fBpcrecpp\fP
144  .\"  .\"
# Line 132  an application that uses PCRE. The heade Line 151  an application that uses PCRE. The heade
151  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.
152  Applications can use these to include support for different releases of PCRE.  Applications can use these to include support for different releases of PCRE.
153  .P  .P
154    In a Windows environment, if you want to statically link an application program
155    against a non-dll \fBpcre.a\fP file, you must define PCRE_STATIC before
156    including \fBpcre.h\fP or \fBpcrecpp.h\fP, because otherwise the
157    \fBpcre_malloc()\fP and \fBpcre_free()\fP exported functions will be declared
158    \fB__declspec(dllimport)\fP, with unwanted results.
159    .P
160  The functions \fBpcre_compile()\fP, \fBpcre_compile2()\fP, \fBpcre_study()\fP,  The functions \fBpcre_compile()\fP, \fBpcre_compile2()\fP, \fBpcre_study()\fP,
161  and \fBpcre_exec()\fP are used for compiling and matching regular expressions  and \fBpcre_exec()\fP are used for compiling and matching regular expressions
162  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 146  documentation, and the Line 171  documentation, and the
171  .\"  .\"
172  documentation describes how to compile and run it.  documentation describes how to compile and run it.
173  .P  .P
174    Just-in-time compiler support is an optional feature of PCRE that can be built
175    in appropriate hardware environments. It greatly speeds up the matching
176    performance of many patterns. Simple programs can easily request that it be
177    used if available, by setting an option that is ignored when it is not
178    relevant. More complicated programs might need to make use of the functions
179    \fBpcre_jit_stack_alloc()\fP, \fBpcre_jit_stack_free()\fP, and
180    \fBpcre_assign_jit_stack()\fP in order to control the JIT code's memory usage.
181    These functions are discussed in the
182    .\" HREF
183    \fBpcrejit\fP
184    .\"
185    documentation.
186    .P
187  A second matching function, \fBpcre_dfa_exec()\fP, which is not  A second matching function, \fBpcre_dfa_exec()\fP, which is not
188  Perl-compatible, is also provided. This uses a different algorithm for the  Perl-compatible, is also provided. This uses a different algorithm for the
189  matching. The alternative algorithm finds all possible matches (at a given  matching. The alternative algorithm finds all possible matches (at a given
# Line 276  callout function pointed to by \fBpcre_c Line 314  callout function pointed to by \fBpcre_c
314  .P  .P
315  The compiled form of a regular expression is not altered during matching, so  The compiled form of a regular expression is not altered during matching, so
316  the same compiled pattern can safely be used by several threads at once.  the same compiled pattern can safely be used by several threads at once.
317    .P
318    If the just-in-time optimization feature is being used, it needs separate
319    memory stack areas for each thread. See the
320    .\" HREF
321    \fBpcrejit\fP
322    .\"
323    documentation for more details.
324  .  .
325  .  .
326  .SH "SAVING PRECOMPILED PATTERNS FOR LATER USE"  .SH "SAVING PRECOMPILED PATTERNS FOR LATER USE"
# Line 318  otherwise it is set to zero. Line 363  otherwise it is set to zero.
363  The output is an integer that is set to one if support for Unicode character  The output is an integer that is set to one if support for Unicode character
364  properties is available; otherwise it is set to zero.  properties is available; otherwise it is set to zero.
365  .sp  .sp
366      PCRE_CONFIG_JIT
367    .sp
368    The output is an integer that is set to one if support for just-in-time
369    compiling is available; otherwise it is set to zero.
370    .sp
371    PCRE_CONFIG_NEWLINE    PCRE_CONFIG_NEWLINE
372  .sp  .sp
373  The output is an integer whose value specifies the default character sequence  The output is an integer whose value specifies the default character sequence
# Line 395  avoiding the use of the stack. Line 445  avoiding the use of the stack.
445  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
446  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
447  the two interfaces is that \fBpcre_compile2()\fP has an additional argument,  the two interfaces is that \fBpcre_compile2()\fP has an additional argument,
448  \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
449  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
450  information applies equally to \fBpcre_compile2()\fP.  information applies equally to \fBpcre_compile2()\fP.
451  .P  .P
452  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 471  within the pattern (see the detailed des
471  .\"  .\"
472  documentation). For those options that can be different in different parts of  documentation). For those options that can be different in different parts of
473  the pattern, the contents of the \fIoptions\fP argument specifies their  the pattern, the contents of the \fIoptions\fP argument specifies their
474  settings at the start of compilation and execution. The PCRE_ANCHORED,  settings at the start of compilation and execution. The PCRE_ANCHORED,
475  PCRE_BSR_\fIxxx\fP, and PCRE_NEWLINE_\fIxxx\fP options can be set at the time  PCRE_BSR_\fIxxx\fP, PCRE_NEWLINE_\fIxxx\fP, PCRE_NO_UTF8_CHECK, and
476  of matching as well as at compile time.  PCRE_NO_START_OPT options can be set at the time of matching as well as at
477    compile time.
478  .P  .P
479  If \fIerrptr\fP is NULL, \fBpcre_compile()\fP returns NULL immediately.  If \fIerrptr\fP is NULL, \fBpcre_compile()\fP returns NULL immediately.
480  Otherwise, if compilation of a pattern fails, \fBpcre_compile()\fP returns  Otherwise, if compilation of a pattern fails, \fBpcre_compile()\fP returns
481  NULL, and sets the variable pointed to by \fIerrptr\fP to point to a textual  NULL, and sets the variable pointed to by \fIerrptr\fP to point to a textual
482  error message. This is a static string that is part of the library. You must  error message. This is a static string that is part of the library. You must
483  not try to free it. The byte offset from the start of the pattern to the  not try to free it. Normally, the offset from the start of the pattern to the
484  character that was being processed when the error was discovered is placed in  byte that was being processed when the error was discovered is placed in the
485  the variable pointed to by \fIerroffset\fP, which must not be NULL. If it is,  variable pointed to by \fIerroffset\fP, which must not be NULL (if it is, an
486  an immediate error is given. Some errors are not detected until checks are  immediate error is given). However, for an invalid UTF-8 string, the offset is
487  carried out when the whole pattern has been scanned; in this case the offset is  that of the first byte of the failing character. Also, some errors are not
488  set to the end of the pattern.  detected until checks are carried out when the whole pattern has been scanned;
489    in these cases the offset passed back is the length of the pattern.
490    .P
491    Note that the offset is in bytes, not characters, even in UTF-8 mode. It may
492    sometimes point into the middle of a UTF-8 character.
493  .P  .P
494  If \fBpcre_compile2()\fP is used instead of \fBpcre_compile()\fP, and the  If \fBpcre_compile2()\fP is used instead of \fBpcre_compile()\fP, and the
495  \fIerrorcodeptr\fP argument is not NULL, a non-zero error code number is  \fIerrorcodeptr\fP argument is not NULL, a non-zero error code number is
# Line 513  pattern. Line 568  pattern.
568  .sp  .sp
569    PCRE_DOTALL    PCRE_DOTALL
570  .sp  .sp
571  If this bit is set, a dot metacharater in the pattern matches all characters,  If this bit is set, a dot metacharacter in the pattern matches a character of
572  including those that indicate newline. Without it, a dot does not match when  any value, including one that indicates a newline. However, it only ever
573  the current position is at a newline. This option is equivalent to Perl's /s  matches one character, even if newlines are coded as CRLF. Without this option,
574  option, and it can be changed within a pattern by a (?s) option setting. A  a dot does not match when the current position is at a newline. This option is
575  negative class such as [^a] always matches newline characters, independent of  equivalent to Perl's /s option, and it can be changed within a pattern by a
576  the setting of this option.  (?s) option setting. A negative class such as [^a] always matches newline
577    characters, independent of the setting of this option.
578  .sp  .sp
579    PCRE_DUPNAMES    PCRE_DUPNAMES
580  .sp  .sp
# Line 540  unescaped # outside a character class an Line 596  unescaped # outside a character class an
596  ignored. This is equivalent to Perl's /x option, and it can be changed within a  ignored. This is equivalent to Perl's /x option, and it can be changed within a
597  pattern by a (?x) option setting.  pattern by a (?x) option setting.
598  .P  .P
599    Which characters are interpreted as newlines is controlled by the options
600    passed to \fBpcre_compile()\fP or by a special sequence at the start of the
601    pattern, as described in the section entitled
602    .\" HTML <a href="pcrepattern.html#newlines">
603    .\" </a>
604    "Newline conventions"
605    .\"
606    in the \fBpcrepattern\fP documentation. Note that the end of this type of
607    comment is a literal newline sequence in the pattern; escape sequences that
608    happen to represent a newline do not count.
609    .P
610  This option makes it possible to include comments inside complicated patterns.  This option makes it possible to include comments inside complicated patterns.
611  Note, however, that this applies only to data characters. Whitespace characters  Note, however, that this applies only to data characters. Whitespace characters
612  may never appear within special character sequences in a pattern, for example  may never appear within special character sequences in a pattern, for example
613  within the sequence (?( which introduces a conditional subpattern.  within the sequence (?( that introduces a conditional subpattern.
614  .sp  .sp
615    PCRE_EXTRA    PCRE_EXTRA
616  .sp  .sp
# Line 553  set, any backslash in a pattern that is Line 620  set, any backslash in a pattern that is
620  special meaning causes an error, thus reserving these combinations for future  special meaning causes an error, thus reserving these combinations for future
621  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
622  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
623  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
624  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)
625    option setting within a pattern.
626  .sp  .sp
627    PCRE_FIRSTLINE    PCRE_FIRSTLINE
628  .sp  .sp
# Line 617  option, the combination may or may not b Line 685  option, the combination may or may not b
685  PCRE_NEWLINE_CR with PCRE_NEWLINE_LF is equivalent to PCRE_NEWLINE_CRLF, but  PCRE_NEWLINE_CR with PCRE_NEWLINE_LF is equivalent to PCRE_NEWLINE_CRLF, but
686  other combinations may yield unused numbers and cause an error.  other combinations may yield unused numbers and cause an error.
687  .P  .P
688  The only time that a line break is specially recognized when compiling a  The only time that a line break in a pattern is specially recognized when
689  pattern is if PCRE_EXTENDED is set, and an unescaped # outside a character  compiling is when PCRE_EXTENDED is set. CR and LF are whitespace characters,
690  class is encountered. This indicates a comment that lasts until after the next  and so are ignored in this mode. Also, an unescaped # outside a character class
691  line break sequence. In other circumstances, line break sequences are treated  indicates a comment that lasts until after the next line break sequence. In
692  as literal data, except that in PCRE_EXTENDED mode, both CR and LF are treated  other circumstances, line break sequences in patterns are treated as literal
693  as whitespace characters and are therefore ignored.  data.
694  .P  .P
695  The newline option that is set at compile time becomes the default that is used  The newline option that is set at compile time becomes the default that is used
696  for \fBpcre_exec()\fP and \fBpcre_dfa_exec()\fP, but it can be overridden.  for \fBpcre_exec()\fP and \fBpcre_dfa_exec()\fP, but it can be overridden.
# Line 635  were followed by ?: but named parenthese Line 703  were followed by ?: but named parenthese
703  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
704  in Perl.  in Perl.
705  .sp  .sp
706      NO_START_OPTIMIZE
707    .sp
708    This is an option that acts at matching time; that is, it is really an option
709    for \fBpcre_exec()\fP or \fBpcre_dfa_exec()\fP. If it is set at compile time,
710    it is remembered with the compiled pattern and assumed at matching time. For
711    details see the discussion of PCRE_NO_START_OPTIMIZE
712    .\" HTML <a href="#execoptions">
713    .\" </a>
714    below.
715    .\"
716    .sp
717      PCRE_UCP
718    .sp
719    This option changes the way PCRE processes \eB, \eb, \eD, \ed, \eS, \es, \eW,
720    \ew, and some of the POSIX character classes. By default, only ASCII characters
721    are recognized, but if PCRE_UCP is set, Unicode properties are used instead to
722    classify characters. More details are given in the section on
723    .\" HTML <a href="pcre.html#genericchartypes">
724    .\" </a>
725    generic character types
726    .\"
727    in the
728    .\" HREF
729    \fBpcrepattern\fP
730    .\"
731    page. If you set PCRE_UCP, matching one of the items it affects takes much
732    longer. The option is available only if PCRE has been compiled with Unicode
733    property support.
734    .sp
735    PCRE_UNGREEDY    PCRE_UNGREEDY
736  .sp  .sp
737  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 648  of UTF-8 characters instead of single-by Line 745  of UTF-8 characters instead of single-by
745  available only when PCRE is built to include UTF-8 support. If not, the use  available only when PCRE is built to include UTF-8 support. If not, the use
746  of this option provokes an error. Details of how this option changes the  of this option provokes an error. Details of how this option changes the
747  behaviour of PCRE are given in the  behaviour of PCRE are given in the
 .\" HTML <a href="pcre.html#utf8support">  
 .\" </a>  
 section on UTF-8 support  
 .\"  
 in the main  
748  .\" HREF  .\" HREF
749  \fBpcre\fP  \fBpcreunicode\fP
750  .\"  .\"
751  page.  page.
752  .sp  .sp
# Line 724  out of use. To avoid confusion, they hav Line 816  out of use. To avoid confusion, they hav
816    34  character value in \ex{...} sequence is too large    34  character value in \ex{...} sequence is too large
817    35  invalid condition (?(0)    35  invalid condition (?(0)
818    36  \eC not allowed in lookbehind assertion    36  \eC not allowed in lookbehind assertion
819    37  PCRE does not support \eL, \el, \eN, \eU, or \eu    37  PCRE does not support \eL, \el, \eN{name}, \eU, or \eu
820    38  number after (?C is > 255    38  number after (?C is > 255
821    39  closing ) for (?C expected    39  closing ) for (?C expected
822    40  recursive call could loop indefinitely    40  recursive call could loop indefinitely
# Line 740  out of use. To avoid confusion, they hav Line 832  out of use. To avoid confusion, they hav
832    50  [this code is not in use]    50  [this code is not in use]
833    51  octal value is greater than \e377 (not in UTF-8 mode)    51  octal value is greater than \e377 (not in UTF-8 mode)
834    52  internal error: overran compiling workspace    52  internal error: overran compiling workspace
835    53  internal error: previously-checked referenced subpattern not found    53  internal error: previously-checked referenced subpattern
836            not found
837    54  DEFINE group contains more than one branch    54  DEFINE group contains more than one branch
838    55  repeating a DEFINE group is not allowed    55  repeating a DEFINE group is not allowed
839    56  inconsistent NEWLINE options    56  inconsistent NEWLINE options
840    57  \eg is not followed by a braced, angle-bracketed, or quoted    57  \eg is not followed by a braced, angle-bracketed, or quoted
841          name/number or by a plain number          name/number or by a plain number
842    58  a numbered reference must not be zero    58  a numbered reference must not be zero
843    59  (*VERB) with an argument is not supported    59  an argument is not allowed for (*ACCEPT), (*FAIL), or (*COMMIT)
844    60  (*VERB) not recognized    60  (*VERB) not recognized
845    61  number is too big    61  number is too big
846    62  subpattern name expected    62  subpattern name expected
847    63  digit expected after (?+    63  digit expected after (?+
848    64  ] is an invalid data character in JavaScript compatibility mode    64  ] is an invalid data character in JavaScript compatibility mode
849      65  different names for subpatterns of the same number are
850            not allowed
851      66  (*MARK) must have an argument
852      67  this version of PCRE is not compiled with PCRE_UCP support
853      68  \ec must be followed by an ASCII character
854      69  \ek is not followed by a braced, angle-bracketed, or quoted name
855  .sp  .sp
856  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
857  be used if the limits were changed when PCRE was built.  be used if the limits were changed when PCRE was built.
858  .  .
859  .  .
860    .\" HTML <a name="studyingapattern"></a>
861  .SH "STUDYING A PATTERN"  .SH "STUDYING A PATTERN"
862  .rs  .rs
863  .sp  .sp
# Line 785  in the section on matching a pattern. Line 885  in the section on matching a pattern.
885  .P  .P
886  If studying the pattern does not produce any useful information,  If studying the pattern does not produce any useful information,
887  \fBpcre_study()\fP returns NULL. In that circumstance, if the calling program  \fBpcre_study()\fP returns NULL. In that circumstance, if the calling program
888  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
889  \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.
890  .P  .P
891  The second argument of \fBpcre_study()\fP contains option bits. At present, no  The second argument of \fBpcre_study()\fP contains option bits. There is only
892  options are defined, and this argument should always be zero.  one option: PCRE_STUDY_JIT_COMPILE. If this is set, and the just-in-time
893    compiler is available, the pattern is further compiled into machine code that
894    executes much faster than the \fBpcre_exec()\fP matching function. If
895    the just-in-time compiler is not available, this option is ignored. All other
896    bits in the \fIoptions\fP argument must be zero.
897    .P
898    JIT compilation is a heavyweight optimization. It can take some time for
899    patterns to be analyzed, and for one-off matches and simple patterns the
900    benefit of faster execution might be offset by a much slower study time.
901    Not all patterns can be optimized by the JIT compiler. For those that cannot be
902    handled, matching automatically falls back to the \fBpcre_exec()\fP
903    interpreter. For more details, see the
904    .\" HREF
905    \fBpcrejit\fP
906    .\"
907    documentation.
908  .P  .P
909  The third argument for \fBpcre_study()\fP is a pointer for an error message. If  The third argument for \fBpcre_study()\fP is a pointer for an error message. If
910  studying succeeds (even if no data is returned), the variable it points to is  studying succeeds (even if no data is returned), the variable it points to is
# Line 798  static string that is part of the librar Line 913  static string that is part of the librar
913  should test the error pointer for NULL after calling \fBpcre_study()\fP, to be  should test the error pointer for NULL after calling \fBpcre_study()\fP, to be
914  sure that it has run successfully.  sure that it has run successfully.
915  .P  .P
916  This is a typical call to \fBpcre_study\fP():  When you are finished with a pattern, you can free the memory used for the
917    study data by calling \fBpcre_free_study()\fP. This function was added to the
918    API for release 8.20. For earlier versions, the memory could be freed with
919    \fBpcre_free()\fP, just like the pattern itself. This will still work in cases
920    where PCRE_STUDY_JIT_COMPILE is not used, but it is advisable to change to the
921    new function when convenient.
922    .P
923    This is a typical way in which \fBpcre_study\fP() is used (except that in a
924    real application there should be tests for errors):
925  .sp  .sp
926    pcre_extra *pe;    int rc;
927    pe = pcre_study(    pcre *re;
928      pcre_extra *sd;
929      re = pcre_compile("pattern", 0, &error, &erroroffset, NULL);
930      sd = pcre_study(
931      re,             /* result of pcre_compile() */      re,             /* result of pcre_compile() */
932      0,              /* no options exist */      0,              /* no options */
933      &error);        /* set to NULL or points to a message */      &error);        /* set to NULL or points to a message */
934      rc = pcre_exec(   /* see below for details of pcre_exec() options */
935        re, sd, "subject", 7, 0, 0, ovector, 30);
936      ...
937      pcre_free_study(sd);
938      pcre_free(re);
939  .sp  .sp
940  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
941  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
942  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
943  guarantee that no shorter strings match. The value is used by  guarantee that no shorter strings match. The value is used by
944  \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
945  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
946  in a calling program via the \fBpcre_fullinfo()\fP function.  in a calling program via the \fBpcre_fullinfo()\fP function.
947  .P  .P
948  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
949  single fixed starting character. A bitmap of possible starting bytes is  single fixed starting character. A bitmap of possible starting bytes is
950  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
951  matching.  matching.
952    .P
953    These two optimizations apply to both \fBpcre_exec()\fP and
954    \fBpcre_dfa_exec()\fP. However, they are not used by \fBpcre_exec()\fP if
955    \fBpcre_study()\fP is called with the PCRE_STUDY_JIT_COMPILE option, and
956    just-in-time compiling is successful. The optimizations can be disabled by
957    setting the PCRE_NO_START_OPTIMIZE option when calling \fBpcre_exec()\fP or
958    \fBpcre_dfa_exec()\fP. You might want to do this if your pattern contains
959    callouts or (*MARK) (which cannot be handled by the JIT compiler), and you want
960    to make use of these facilities in cases where matching fails. See the
961    discussion of PCRE_NO_START_OPTIMIZE
962    .\" HTML <a href="#execoptions">
963    .\" </a>
964    below.
965    .\"
966  .  .
967  .  .
968  .\" HTML <a name="localesupport"></a>  .\" HTML <a name="localesupport"></a>
# Line 827  matching. Line 972  matching.
972  PCRE handles caseless matching, and determines whether characters are letters,  PCRE handles caseless matching, and determines whether characters are letters,
973  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
974  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
975  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
976  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
977  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
978  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
979  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
980    handling characters with codes greater than 128, you should either use UTF-8
981    and Unicode, or use locales, but not try to mix the two.
982  .P  .P
983  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
984  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 876  one in which it was compiled. Passing ta Line 1023  one in which it was compiled. Passing ta
1023  below in the section on matching a pattern.  below in the section on matching a pattern.
1024  .  .
1025  .  .
1026    .\" HTML <a name="infoaboutpattern"></a>
1027  .SH "INFORMATION ABOUT A PATTERN"  .SH "INFORMATION ABOUT A PATTERN"
1028  .rs  .rs
1029  .sp  .sp
# Line 907  check against passing an arbitrary memor Line 1055  check against passing an arbitrary memor
1055    size_t length;    size_t length;
1056    rc = pcre_fullinfo(    rc = pcre_fullinfo(
1057      re,               /* result of pcre_compile() */      re,               /* result of pcre_compile() */
1058      pe,               /* result of pcre_study(), or NULL */      sd,               /* result of pcre_study(), or NULL */
1059      PCRE_INFO_SIZE,   /* what is required */      PCRE_INFO_SIZE,   /* what is required */
1060      &length);         /* where to put the data */      &length);         /* where to put the data */
1061  .sp  .sp
# Line 972  Return 1 if the (?J) or (?-J) option set Line 1120  Return 1 if the (?J) or (?-J) option set
1120  0. The fourth argument should point to an \fBint\fP variable. (?J) and  0. The fourth argument should point to an \fBint\fP variable. (?J) and
1121  (?-J) set and unset the local PCRE_DUPNAMES option, respectively.  (?-J) set and unset the local PCRE_DUPNAMES option, respectively.
1122  .sp  .sp
1123      PCRE_INFO_JIT
1124    .sp
1125    Return 1 if the pattern was studied with the PCRE_STUDY_JIT_COMPILE option, and
1126    just-in-time compiling was successful. The fourth argument should point to an
1127    \fBint\fP variable. A return value of 0 means that JIT support is not available
1128    in this version of PCRE, or that the pattern was not studied with the
1129    PCRE_STUDY_JIT_COMPILE option, or that the JIT compiler could not handle this
1130    particular pattern. See the
1131    .\" HREF
1132    \fBpcrejit\fP
1133    .\"
1134    documentation for details of what can and cannot be handled.
1135    .sp
1136    PCRE_INFO_LASTLITERAL    PCRE_INFO_LASTLITERAL
1137  .sp  .sp
1138  Return the value of the rightmost literal byte that must exist in any matched  Return the value of the rightmost literal byte that must exist in any matched
# Line 1012  entry; both of these return an \fBint\fP Line 1173  entry; both of these return an \fBint\fP
1173  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
1174  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
1175  are the number of the capturing parenthesis, most significant byte first. The  are the number of the capturing parenthesis, most significant byte first. The
1176  rest of the entry is the corresponding name, zero terminated.  rest of the entry is the corresponding name, zero terminated.
1177  .P  .P
1178  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
1179  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 1185  in the
1185  .\" HREF  .\" HREF
1186  \fBpcrepattern\fP  \fBpcrepattern\fP
1187  .\"  .\"
1188  page. Duplicate names for subpatterns with different numbers are permitted only  page. Duplicate names for subpatterns with different numbers are permitted only
1189  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
1190  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
1191  (?| 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
1192  necessarily the case because later subpatterns may have lower numbers.  necessarily the case because later subpatterns may have lower numbers.
1193  .P  .P
1194  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 1094  variable. Line 1255  variable.
1255  .sp  .sp
1256    PCRE_INFO_STUDYSIZE    PCRE_INFO_STUDYSIZE
1257  .sp  .sp
1258  Return the size of the data block pointed to by the \fIstudy_data\fP field in  Return the size of the data block pointed to by the \fIstudy_data\fP field in a
1259  a \fBpcre_extra\fP block. That is, it is the value that was passed to  \fBpcre_extra\fP block. If \fBpcre_extra\fP is NULL, or there is no study data,
1260  \fBpcre_malloc()\fP when PCRE was getting memory into which to place the data  zero is returned. The fourth argument should point to a \fBsize_t\fP variable.
1261  created by \fBpcre_study()\fP. If \fBpcre_extra\fP is NULL, or there is no  The \fIstudy_data\fP field is set by \fBpcre_study()\fP to record information
1262  study data, zero is returned. The fourth argument should point to a  that will speed up matching (see the section entitled
1263  \fBsize_t\fP variable.  .\" HTML <a href="#studyingapattern">
1264    .\" </a>
1265    "Studying a pattern"
1266    .\"
1267    above). The format of the \fIstudy_data\fP block is private, but its length
1268    is made available via this option so that it can be saved and restored (see the
1269    .\" HREF
1270    \fBpcreprecompile\fP
1271    .\"
1272    documentation for details).
1273  .  .
1274  .  .
1275  .SH "OBSOLETE INFO FUNCTION"  .SH "OBSOLETE INFO FUNCTION"
# Line 1194  Here is an example of a simple call to \ Line 1364  Here is an example of a simple call to \
1364      ovector,        /* vector of integers for substring information */      ovector,        /* vector of integers for substring information */
1365      30);            /* number of elements (NOT size in bytes) */      30);            /* number of elements (NOT size in bytes) */
1366  .  .
1367    .
1368  .\" HTML <a name="extradata"></a>  .\" HTML <a name="extradata"></a>
1369  .SS "Extra data for \fBpcre_exec()\fR"  .SS "Extra data for \fBpcre_exec()\fR"
1370  .rs  .rs
# Line 1206  fields (not necessarily in this order): Line 1377  fields (not necessarily in this order):
1377  .sp  .sp
1378    unsigned long int \fIflags\fP;    unsigned long int \fIflags\fP;
1379    void *\fIstudy_data\fP;    void *\fIstudy_data\fP;
1380      void *\fIexecutable_jit\fP;
1381    unsigned long int \fImatch_limit\fP;    unsigned long int \fImatch_limit\fP;
1382    unsigned long int \fImatch_limit_recursion\fP;    unsigned long int \fImatch_limit_recursion\fP;
1383    void *\fIcallout_data\fP;    void *\fIcallout_data\fP;
1384    const unsigned char *\fItables\fP;    const unsigned char *\fItables\fP;
1385      unsigned char **\fImark\fP;
1386  .sp  .sp
1387  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
1388  are set. The flag bits are:  are set. The flag bits are:
1389  .sp  .sp
1390    PCRE_EXTRA_STUDY_DATA    PCRE_EXTRA_STUDY_DATA
1391      PCRE_EXTRA_EXECUTABLE_JIT
1392    PCRE_EXTRA_MATCH_LIMIT    PCRE_EXTRA_MATCH_LIMIT
1393    PCRE_EXTRA_MATCH_LIMIT_RECURSION    PCRE_EXTRA_MATCH_LIMIT_RECURSION
1394    PCRE_EXTRA_CALLOUT_DATA    PCRE_EXTRA_CALLOUT_DATA
1395    PCRE_EXTRA_TABLES    PCRE_EXTRA_TABLES
1396      PCRE_EXTRA_MARK
1397  .sp  .sp
1398  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 and sometimes
1399  \fBpcre_extra\fP block that is returned by \fBpcre_study()\fP, together with  the \fIexecutable_jit\fP field are set in the \fBpcre_extra\fP block that is
1400  the appropriate flag bit. You should not set this yourself, but you may add to  returned by \fBpcre_study()\fP, together with the appropriate flag bits. You
1401  the block by setting the other fields and their corresponding flag bits.  should not set these yourself, but you may add to the block by setting the
1402    other fields and their corresponding flag bits.
1403  .P  .P
1404  The \fImatch_limit\fP field provides a means of preventing PCRE from using up a  The \fImatch_limit\fP field provides a means of preventing PCRE from using up a
1405  vast amount of resources when running patterns that are not going to match,  vast amount of resources when running patterns that are not going to match,
1406  but which have a very large number of possibilities in their search trees. The  but which have a very large number of possibilities in their search trees. The
1407  classic example is a pattern that uses nested unlimited repeats.  classic example is a pattern that uses nested unlimited repeats.
1408  .P  .P
1409  Internally, PCRE uses a function called \fBmatch()\fP which it calls repeatedly  Internally, \fBpcre_exec()\fP uses a function called \fBmatch()\fP, which it
1410  (sometimes recursively). The limit set by \fImatch_limit\fP is imposed on the  calls repeatedly (sometimes recursively). The limit set by \fImatch_limit\fP is
1411  number of times this function is called during a match, which has the effect of  imposed on the number of times this function is called during a match, which
1412  limiting the amount of backtracking that can take place. For patterns that are  has the effect of limiting the amount of backtracking that can take place. For
1413  not anchored, the count restarts from zero for each position in the subject  patterns that are not anchored, the count restarts from zero for each position
1414  string.  in the subject string.
1415    .P
1416    When \fBpcre_exec()\fP is called with a pattern that was successfully studied
1417    with the PCRE_STUDY_JIT_COMPILE option, the way that the matching is executed
1418    is entirely different. However, there is still the possibility of runaway
1419    matching that goes on for a very long time, and so the \fImatch_limit\fP value
1420    is also used in this case (but in a different way) to limit how long the
1421    matching can continue.
1422  .P  .P
1423  The default value for the limit can be set when PCRE is built; the default  The default value for the limit can be set when PCRE is built; the default
1424  default is 10 million, which handles all but the most extreme cases. You can  default is 10 million, which handles all but the most extreme cases. You can
# Line 1250  limits the depth of recursion. The recur Line 1433  limits the depth of recursion. The recur
1433  total number of calls, because not all calls to \fBmatch()\fP are recursive.  total number of calls, because not all calls to \fBmatch()\fP are recursive.
1434  This limit is of use only if it is set smaller than \fImatch_limit\fP.  This limit is of use only if it is set smaller than \fImatch_limit\fP.
1435  .P  .P
1436  Limiting the recursion depth limits the amount of stack that can be used, or,  Limiting the recursion depth limits the amount of machine stack that can be
1437  when PCRE has been compiled to use memory on the heap instead of the stack, the  used, or, when PCRE has been compiled to use memory on the heap instead of the
1438  amount of heap memory that can be used.  stack, the amount of heap memory that can be used. This limit is not relevant,
1439    and is ignored, if the pattern was successfully studied with
1440    PCRE_STUDY_JIT_COMPILE.
1441  .P  .P
1442  The default value for \fImatch_limit_recursion\fP can be set when PCRE is  The default value for \fImatch_limit_recursion\fP can be set when PCRE is
1443  built; the default default is the same value as the default for  built; the default default is the same value as the default for
# Line 1281  called. See the Line 1466  called. See the
1466  \fBpcreprecompile\fP  \fBpcreprecompile\fP
1467  .\"  .\"
1468  documentation for a discussion of saving compiled patterns for later use.  documentation for a discussion of saving compiled patterns for later use.
1469    .P
1470    If PCRE_EXTRA_MARK is set in the \fIflags\fP field, the \fImark\fP field must
1471    be set to point to a \fBchar *\fP variable. If the pattern contains any
1472    backtracking control verbs such as (*MARK:NAME), and the execution ends up with
1473    a name to pass back, a pointer to the name string (zero terminated) is placed
1474    in the variable pointed to by the \fImark\fP field. The names are within the
1475    compiled pattern; if you wish to retain such a name you must copy it before
1476    freeing the memory of a compiled pattern. If there is no name to pass back, the
1477    variable pointed to by the \fImark\fP field set to NULL. For details of the
1478    backtracking control verbs, see the section entitled
1479    .\" HTML <a href="pcrepattern#backtrackcontrol">
1480    .\" </a>
1481    "Backtracking control"
1482    .\"
1483    in the
1484    .\" HREF
1485    \fBpcrepattern\fP
1486    .\"
1487    documentation.
1488    .
1489  .  .
1490  .\" HTML <a name="execoptions"></a>  .\" HTML <a name="execoptions"></a>
1491  .SS "Option bits for \fBpcre_exec()\fP"  .SS "Option bits for \fBpcre_exec()\fP"
# Line 1291  zero. The only bits that may be set are Line 1496  zero. The only bits that may be set are
1496  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NOTEMPTY_ATSTART,  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NOTEMPTY_ATSTART,
1497  PCRE_NO_START_OPTIMIZE, PCRE_NO_UTF8_CHECK, PCRE_PARTIAL_SOFT, and  PCRE_NO_START_OPTIMIZE, PCRE_NO_UTF8_CHECK, PCRE_PARTIAL_SOFT, and
1498  PCRE_PARTIAL_HARD.  PCRE_PARTIAL_HARD.
1499    .P
1500    If the pattern was successfully studied with the PCRE_STUDY_JIT_COMPILE option,
1501    the only supported options for JIT execution are PCRE_NO_UTF8_CHECK,
1502    PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, and PCRE_NOTEMPTY_ATSTART. Note in
1503    particular that partial matching is not supported. If an unsupported option is
1504    used, JIT execution is disabled and the normal interpretive code in
1505    \fBpcre_exec()\fP is run.
1506  .sp  .sp
1507    PCRE_ANCHORED    PCRE_ANCHORED
1508  .sp  .sp
# Line 1371  valid, so PCRE searches further into the Line 1583  valid, so PCRE searches further into the
1583  .sp  .sp
1584    PCRE_NOTEMPTY_ATSTART    PCRE_NOTEMPTY_ATSTART
1585  .sp  .sp
1586  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
1587  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
1588  can occur only if the pattern contains \eK.  can occur only if the pattern contains \eK.
1589  .P  .P
# Line 1386  the Line 1598  the
1598  .\" HREF  .\" HREF
1599  \fBpcredemo\fP  \fBpcredemo\fP
1600  .\"  .\"
1601  sample program.  sample program. In the most general case, you have to check to see if the
1602    newline convention recognizes CRLF as a newline, and if so, and the current
1603    character is CR followed by LF, advance the starting offset by two characters
1604    instead of one.
1605  .sp  .sp
1606    PCRE_NO_START_OPTIMIZE    PCRE_NO_START_OPTIMIZE
1607  .sp  .sp
1608  There are a number of optimizations that \fBpcre_exec()\fP uses at the start of  There are a number of optimizations that \fBpcre_exec()\fP uses at the start of
1609  a match, in order to speed up the process. For example, if it is known that a  a match, in order to speed up the process. For example, if it is known that an
1610  match must start with a specific character, it searches the subject for that  unanchored match must start with a specific character, it searches the subject
1611  character, and fails immediately if it cannot find it, without actually running  for that character, and fails immediately if it cannot find it, without
1612  the main matching function. When callouts are in use, these optimizations can  actually running the main matching function. This means that a special item
1613  cause them to be skipped. This option disables the "start-up" optimizations,  such as (*COMMIT) at the start of a pattern is not considered until after a
1614  causing performance to suffer, but ensuring that the callouts do occur.  suitable starting point for the match has been found. When callouts or (*MARK)
1615    items are in use, these "start-up" optimizations can cause them to be skipped
1616    if the pattern is never actually used. The start-up optimizations are in effect
1617    a pre-scan of the subject that takes place before the pattern is run.
1618    .P
1619    The PCRE_NO_START_OPTIMIZE option disables the start-up optimizations, possibly
1620    causing performance to suffer, but ensuring that in cases where the result is
1621    "no match", the callouts do occur, and that items such as (*COMMIT) and (*MARK)
1622    are considered at every possible starting position in the subject string. If
1623    PCRE_NO_START_OPTIMIZE is set at compile time, it cannot be unset at matching
1624    time.
1625    .P
1626    Setting PCRE_NO_START_OPTIMIZE can change the outcome of a matching operation.
1627    Consider the pattern
1628    .sp
1629      (*COMMIT)ABC
1630    .sp
1631    When this is compiled, PCRE records the fact that a match must start with the
1632    character "A". Suppose the subject string is "DEFABC". The start-up
1633    optimization scans along the subject, finds "A" and runs the first match
1634    attempt from there. The (*COMMIT) item means that the pattern must match the
1635    current starting position, which in this case, it does. However, if the same
1636    match is run with PCRE_NO_START_OPTIMIZE set, the initial scan along the
1637    subject string does not happen. The first match attempt is run starting from
1638    "D" and when this fails, (*COMMIT) prevents any further matches being tried, so
1639    the overall result is "no match". If the pattern is studied, more start-up
1640    optimizations may be used. For example, a minimum length for the subject may be
1641    recorded. Consider the pattern
1642    .sp
1643      (*MARK:A)(X|Y)
1644    .sp
1645    The minimum length for a match is one character. If the subject is "ABC", there
1646    will be attempts to match "ABC", "BC", "C", and then finally an empty string.
1647    If the pattern is studied, the final attempt does not take place, because PCRE
1648    knows that the subject is too short, and so the (*MARK) is never encountered.
1649    In this case, studying the pattern does not affect the overall match result,
1650    which is still "no match", but it does affect the auxiliary information that is
1651    returned.
1652  .sp  .sp
1653    PCRE_NO_UTF8_CHECK    PCRE_NO_UTF8_CHECK
1654  .sp  .sp
# Line 1414  in the main Line 1666  in the main
1666  \fBpcre\fP  \fBpcre\fP
1667  .\"  .\"
1668  page. If an invalid UTF-8 sequence of bytes is found, \fBpcre_exec()\fP returns  page. If an invalid UTF-8 sequence of bytes is found, \fBpcre_exec()\fP returns
1669  the error PCRE_ERROR_BADUTF8. If \fIstartoffset\fP contains an invalid value,  the error PCRE_ERROR_BADUTF8 or, if PCRE_PARTIAL_HARD is set and the problem is
1670  PCRE_ERROR_BADUTF8_OFFSET is returned.  a truncated UTF-8 character at the end of the subject, PCRE_ERROR_SHORTUTF8. In
1671    both cases, information about the precise nature of the error may also be
1672    returned (see the descriptions of these errors in the section entitled \fIError
1673    return values from\fP \fBpcre_exec()\fP
1674    .\" HTML <a href="#errorlist">
1675    .\" </a>
1676    below).
1677    .\"
1678    If \fIstartoffset\fP contains a value that does not point to the start of a
1679    UTF-8 character (or to the end of the subject), PCRE_ERROR_BADUTF8_OFFSET is
1680    returned.
1681  .P  .P
1682  If you already know that your subject is valid, and you want to skip these  If you already know that your subject is valid, and you want to skip these
1683  checks for performance reasons, you can set the PCRE_NO_UTF8_CHECK option when  checks for performance reasons, you can set the PCRE_NO_UTF8_CHECK option when
1684  calling \fBpcre_exec()\fP. You might want to do this for the second and  calling \fBpcre_exec()\fP. You might want to do this for the second and
1685  subsequent calls to \fBpcre_exec()\fP if you are making repeated calls to find  subsequent calls to \fBpcre_exec()\fP if you are making repeated calls to find
1686  all the matches in a single subject string. However, you should be sure that  all the matches in a single subject string. However, you should be sure that
1687  the value of \fIstartoffset\fP points to the start of a UTF-8 character. When  the value of \fIstartoffset\fP points to the start of a UTF-8 character (or the
1688  PCRE_NO_UTF8_CHECK is set, the effect of passing an invalid UTF-8 string as a  end of the subject). When PCRE_NO_UTF8_CHECK is set, the effect of passing an
1689  subject, or a value of \fIstartoffset\fP that does not point to the start of a  invalid UTF-8 string as a subject or an invalid value of \fIstartoffset\fP is
1690  UTF-8 character, is undefined. Your program may crash.  undefined. Your program may crash.
1691  .sp  .sp
1692    PCRE_PARTIAL_HARD    PCRE_PARTIAL_HARD
1693    PCRE_PARTIAL_SOFT    PCRE_PARTIAL_SOFT
1694  .sp  .sp
1695  These options turn on the partial matching feature. For backwards  These options turn on the partial matching feature. For backwards
1696  compatibility, PCRE_PARTIAL is a synonym for PCRE_PARTIAL_SOFT. A partial match  compatibility, PCRE_PARTIAL is a synonym for PCRE_PARTIAL_SOFT. A partial match
1697  occurs if the end of the subject string is reached successfully, but there are  occurs if the end of the subject string is reached successfully, but there are
1698  not enough subject characters to complete the match. If this happens when  not enough subject characters to complete the match. If this happens when
1699  PCRE_PARTIAL_HARD is set, \fBpcre_exec()\fP immediately returns  PCRE_PARTIAL_SOFT (but not PCRE_PARTIAL_HARD) is set, matching continues by
1700  PCRE_ERROR_PARTIAL. Otherwise, if PCRE_PARTIAL_SOFT is set, matching continues  testing any remaining alternatives. Only if no complete match can be found is
1701  by testing any other alternatives. Only if they all fail is PCRE_ERROR_PARTIAL  PCRE_ERROR_PARTIAL returned instead of PCRE_ERROR_NOMATCH. In other words,
1702  returned (instead of PCRE_ERROR_NOMATCH). The portion of the string that  PCRE_PARTIAL_SOFT says that the caller is prepared to handle a partial match,
1703  was inspected when the partial match was found is set as the first matching  but only if no complete match can be found.
1704  string. There is a more detailed discussion in the  .P
1705    If PCRE_PARTIAL_HARD is set, it overrides PCRE_PARTIAL_SOFT. In this case, if a
1706    partial match is found, \fBpcre_exec()\fP immediately returns
1707    PCRE_ERROR_PARTIAL, without considering any other alternatives. In other words,
1708    when PCRE_PARTIAL_HARD is set, a partial match is considered to be more
1709    important that an alternative complete match.
1710    .P
1711    In both cases, the portion of the string that was inspected when the partial
1712    match was found is set as the first matching string. There is a more detailed
1713    discussion of partial and multi-segment matching, with examples, in the
1714  .\" HREF  .\" HREF
1715  \fBpcrepartial\fP  \fBpcrepartial\fP
1716  .\"  .\"
1717  documentation.  documentation.
1718  .  .
1719    .
1720  .SS "The string to be matched by \fBpcre_exec()\fP"  .SS "The string to be matched by \fBpcre_exec()\fP"
1721  .rs  .rs
1722  .sp  .sp
1723  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
1724  \fIsubject\fP, a length (in bytes) in \fIlength\fP, and a starting byte offset  \fIsubject\fP, a length (in bytes) in \fIlength\fP, and a starting byte offset
1725  in \fIstartoffset\fP. In UTF-8 mode, the byte offset must point to the start of  in \fIstartoffset\fP. If this is negative or greater than the length of the
1726  a UTF-8 character. Unlike the pattern string, the subject may contain binary  subject, \fBpcre_exec()\fP returns PCRE_ERROR_BADOFFSET. When the starting
1727  zero bytes. When the starting offset is zero, the search for a match starts at  offset is zero, the search for a match starts at the beginning of the subject,
1728  the beginning of the subject, and this is by far the most common case.  and this is by far the most common case. In UTF-8 mode, the byte offset must
1729    point to the start of a UTF-8 character (or the end of the subject). Unlike the
1730    pattern string, the subject may contain binary zero bytes.
1731  .P  .P
1732  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
1733  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 1473  start of the subject, which is deemed to Line 1747  start of the subject, which is deemed to
1747  set to 4, it finds the second occurrence of "iss" because it is able to look  set to 4, it finds the second occurrence of "iss" because it is able to look
1748  behind the starting point to discover that it is preceded by a letter.  behind the starting point to discover that it is preceded by a letter.
1749  .P  .P
1750    Finding all the matches in a subject is tricky when the pattern can match an
1751    empty string. It is possible to emulate Perl's /g behaviour by first trying the
1752    match again at the same offset, with the PCRE_NOTEMPTY_ATSTART and
1753    PCRE_ANCHORED options, and then if that fails, advancing the starting offset
1754    and trying an ordinary match again. There is some code that demonstrates how to
1755    do this in the
1756    .\" HREF
1757    \fBpcredemo\fP
1758    .\"
1759    sample program. In the most general case, you have to check to see if the
1760    newline convention recognizes CRLF as a newline, and if so, and the current
1761    character is CR followed by LF, advance the starting offset by two characters
1762    instead of one.
1763    .P
1764  If a non-zero starting offset is passed when the pattern is anchored, one  If a non-zero starting offset is passed when the pattern is anchored, one
1765  attempt to match at the given offset is made. This can only succeed if the  attempt to match at the given offset is made. This can only succeed if the
1766  pattern does not require the match to be at the start of the subject.  pattern does not require the match to be at the start of the subject.
1767  .  .
1768    .
1769  .SS "How \fBpcre_exec()\fP returns captured substrings"  .SS "How \fBpcre_exec()\fP returns captured substrings"
1770  .rs  .rs
1771  .sp  .sp
# Line 1520  string that it matched that is returned. Line 1809  string that it matched that is returned.
1809  .P  .P
1810  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
1811  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
1812  returns a value of zero. If the substring offsets are not of interest,  returns a value of zero. If neither the actual string matched not any captured
1813  \fBpcre_exec()\fP may be called with \fIovector\fP passed as NULL and  substrings are of interest, \fBpcre_exec()\fP may be called with \fIovector\fP
1814  \fIovecsize\fP as zero. However, if the pattern contains back references and  passed as NULL and \fIovecsize\fP as zero. However, if the pattern contains
1815  the \fIovector\fP is not big enough to remember the related substrings, PCRE  back references and the \fIovector\fP is not big enough to remember the related
1816  has to get additional memory for use during matching. Thus it is usually  substrings, PCRE has to get additional memory for use during matching. Thus it
1817  advisable to supply an \fIovector\fP.  is usually advisable to supply an \fIovector\fP of reasonable size.
1818    .P
1819    There are some cases where zero is returned (indicating vector overflow) when
1820    in fact the vector is exactly the right size for the final match. For example,
1821    consider the pattern
1822    .sp
1823      (a)(?:(b)c|bd)
1824    .sp
1825    If a vector of 6 elements (allowing for only 1 captured substring) is given
1826    with subject string "abd", \fBpcre_exec()\fP will try to set the second
1827    captured string, thereby recording a vector overflow, before failing to match
1828    "c" and backing up to try the second alternative. The zero return, however,
1829    does correctly indicate that the maximum number of slots (namely 2) have been
1830    filled. In similar cases where there is temporary overflow, but the final
1831    number of used slots is actually less than the maximum, a non-zero value is
1832    returned.
1833  .P  .P
1834  The \fBpcre_fullinfo()\fP function can be used to find out how many capturing  The \fBpcre_fullinfo()\fP function can be used to find out how many capturing
1835  subpatterns there are in a compiled pattern. The smallest size for  subpatterns there are in a compiled pattern. The smallest size for
# Line 1543  Offset values that correspond to unused Line 1847  Offset values that correspond to unused
1847  expression are also set to -1. For example, if the string "abc" is matched  expression are also set to -1. For example, if the string "abc" is matched
1848  against the pattern (abc)(x(yz)?)? subpatterns 2 and 3 are not matched. The  against the pattern (abc)(x(yz)?)? subpatterns 2 and 3 are not matched. The
1849  return from the function is 2, because the highest used capturing subpattern  return from the function is 2, because the highest used capturing subpattern
1850  number is 1. However, you can refer to the offsets for the second and third  number is 1, and the offsets for for the second and third capturing subpatterns
1851  capturing subpatterns if you wish (assuming the vector is large enough, of  (assuming the vector is large enough, of course) are set to -1.
1852  course).  .P
1853    \fBNote\fP: Elements in the first two-thirds of \fIovector\fP that do not
1854    correspond to capturing parentheses in the pattern are never changed. That is,
1855    if a pattern contains \fIn\fP capturing parentheses, no more than
1856    \fIovector[0]\fP to \fIovector[2n+1]\fP are set by \fBpcre_exec()\fP. The other
1857    elements (in the first two-thirds) retain whatever values they previously had.
1858  .P  .P
1859  Some convenience functions are provided for extracting the captured substrings  Some convenience functions are provided for extracting the captured substrings
1860  as separate strings. These are described below.  as separate strings. These are described below.
1861  .  .
1862    .
1863  .\" HTML <a name="errorlist"></a>  .\" HTML <a name="errorlist"></a>
1864  .SS "Error return values from \fBpcre_exec()\fP"  .SS "Error return values from \fBpcre_exec()\fP"
1865  .rs  .rs
# Line 1591  If a pattern contains back references, b Line 1901  If a pattern contains back references, b
1901  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
1902  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
1903  automatically freed at the end of matching.  automatically freed at the end of matching.
1904    .P
1905    This error is also given if \fBpcre_stack_malloc()\fP fails in
1906    \fBpcre_exec()\fP. This can happen only when PCRE has been compiled with
1907    \fB--disable-stack-for-recursion\fP.
1908  .sp  .sp
1909    PCRE_ERROR_NOSUBSTRING    (-7)    PCRE_ERROR_NOSUBSTRING    (-7)
1910  .sp  .sp
# Line 1615  documentation for details. Line 1929  documentation for details.
1929  .sp  .sp
1930    PCRE_ERROR_BADUTF8        (-10)    PCRE_ERROR_BADUTF8        (-10)
1931  .sp  .sp
1932  A string that contains an invalid UTF-8 byte sequence was passed as a subject.  A string that contains an invalid UTF-8 byte sequence was passed as a subject,
1933    and the PCRE_NO_UTF8_CHECK option was not set. If the size of the output vector
1934    (\fIovecsize\fP) is at least 2, the byte offset to the start of the the invalid
1935    UTF-8 character is placed in the first element, and a reason code is placed in
1936    the second element. The reason codes are listed in the
1937    .\" HTML <a href="#badutf8reasons">
1938    .\" </a>
1939    following section.
1940    .\"
1941    For backward compatibility, if PCRE_PARTIAL_HARD is set and the problem is a
1942    truncated UTF-8 character at the end of the subject (reason codes 1 to 5),
1943    PCRE_ERROR_SHORTUTF8 is returned instead of PCRE_ERROR_BADUTF8.
1944  .sp  .sp
1945    PCRE_ERROR_BADUTF8_OFFSET (-11)    PCRE_ERROR_BADUTF8_OFFSET (-11)
1946  .sp  .sp
1947  The UTF-8 byte sequence that was passed as a subject was valid, but the value  The UTF-8 byte sequence that was passed as a subject was checked and found to
1948  of \fIstartoffset\fP did not point to the beginning of a UTF-8 character.  be valid (the PCRE_NO_UTF8_CHECK option was not set), but the value of
1949    \fIstartoffset\fP did not point to the beginning of a UTF-8 character or the
1950    end of the subject.
1951  .sp  .sp
1952    PCRE_ERROR_PARTIAL        (-12)    PCRE_ERROR_PARTIAL        (-12)
1953  .sp  .sp
# Line 1634  documentation for details of partial mat Line 1961  documentation for details of partial mat
1961  .sp  .sp
1962  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
1963  option was used with a compiled pattern containing items that were not  option was used with a compiled pattern containing items that were not
1964  supported for partial matching. From release 8.00 onwards, there are no  supported for partial matching. From release 8.00 onwards, there are no
1965  restrictions on partial matching.  restrictions on partial matching.
1966  .sp  .sp
1967    PCRE_ERROR_INTERNAL       (-14)    PCRE_ERROR_INTERNAL       (-14)
# Line 1655  description above. Line 1982  description above.
1982    PCRE_ERROR_BADNEWLINE     (-23)    PCRE_ERROR_BADNEWLINE     (-23)
1983  .sp  .sp
1984  An invalid combination of PCRE_NEWLINE_\fIxxx\fP options was given.  An invalid combination of PCRE_NEWLINE_\fIxxx\fP options was given.
1985    .sp
1986      PCRE_ERROR_BADOFFSET      (-24)
1987    .sp
1988    The value of \fIstartoffset\fP was negative or greater than the length of the
1989    subject, that is, the value in \fIlength\fP.
1990    .sp
1991      PCRE_ERROR_SHORTUTF8      (-25)
1992    .sp
1993    This error is returned instead of PCRE_ERROR_BADUTF8 when the subject string
1994    ends with a truncated UTF-8 character and the PCRE_PARTIAL_HARD option is set.
1995    Information about the failure is returned as for PCRE_ERROR_BADUTF8. It is in
1996    fact sufficient to detect this case, but this special error code for
1997    PCRE_PARTIAL_HARD precedes the implementation of returned information; it is
1998    retained for backwards compatibility.
1999    .sp
2000      PCRE_ERROR_RECURSELOOP    (-26)
2001    .sp
2002    This error is returned when \fBpcre_exec()\fP detects a recursion loop within
2003    the pattern. Specifically, it means that either the whole pattern or a
2004    subpattern has been called recursively for the second time at the same position
2005    in the subject string. Some simple patterns that might do this are detected and
2006    faulted at compile time, but more complicated cases, in particular mutual
2007    recursions between two different subpatterns, cannot be detected until run
2008    time.
2009    .sp
2010      PCRE_ERROR_JIT_STACKLIMIT (-27)
2011    .sp
2012    This error is returned when a pattern that was successfully studied using the
2013    PCRE_STUDY_JIT_COMPILE option is being matched, but the memory available for
2014    the just-in-time processing stack is not large enough. See the
2015    .\" HREF
2016    \fBpcrejit\fP
2017    .\"
2018    documentation for more details.
2019  .P  .P
2020  Error numbers -16 to -20 and -22 are not used by \fBpcre_exec()\fP.  Error numbers -16 to -20 and -22 are not used by \fBpcre_exec()\fP.
2021  .  .
2022  .  .
2023    .\" HTML <a name="badutf8reasons"></a>
2024    .SS "Reason codes for invalid UTF-8 strings"
2025    .rs
2026    .sp
2027    When \fBpcre_exec()\fP returns either PCRE_ERROR_BADUTF8 or
2028    PCRE_ERROR_SHORTUTF8, and the size of the output vector (\fIovecsize\fP) is at
2029    least 2, the offset of the start of the invalid UTF-8 character is placed in
2030    the first output vector element (\fIovector[0]\fP) and a reason code is placed
2031    in the second element (\fIovector[1]\fP). The reason codes are given names in
2032    the \fBpcre.h\fP header file:
2033    .sp
2034      PCRE_UTF8_ERR1
2035      PCRE_UTF8_ERR2
2036      PCRE_UTF8_ERR3
2037      PCRE_UTF8_ERR4
2038      PCRE_UTF8_ERR5
2039    .sp
2040    The string ends with a truncated UTF-8 character; the code specifies how many
2041    bytes are missing (1 to 5). Although RFC 3629 restricts UTF-8 characters to be
2042    no longer than 4 bytes, the encoding scheme (originally defined by RFC 2279)
2043    allows for up to 6 bytes, and this is checked first; hence the possibility of
2044    4 or 5 missing bytes.
2045    .sp
2046      PCRE_UTF8_ERR6
2047      PCRE_UTF8_ERR7
2048      PCRE_UTF8_ERR8
2049      PCRE_UTF8_ERR9
2050      PCRE_UTF8_ERR10
2051    .sp
2052    The two most significant bits of the 2nd, 3rd, 4th, 5th, or 6th byte of the
2053    character do not have the binary value 0b10 (that is, either the most
2054    significant bit is 0, or the next bit is 1).
2055    .sp
2056      PCRE_UTF8_ERR11
2057      PCRE_UTF8_ERR12
2058    .sp
2059    A character that is valid by the RFC 2279 rules is either 5 or 6 bytes long;
2060    these code points are excluded by RFC 3629.
2061    .sp
2062      PCRE_UTF8_ERR13
2063    .sp
2064    A 4-byte character has a value greater than 0x10fff; these code points are
2065    excluded by RFC 3629.
2066    .sp
2067      PCRE_UTF8_ERR14
2068    .sp
2069    A 3-byte character has a value in the range 0xd800 to 0xdfff; this range of
2070    code points are reserved by RFC 3629 for use with UTF-16, and so are excluded
2071    from UTF-8.
2072    .sp
2073      PCRE_UTF8_ERR15
2074      PCRE_UTF8_ERR16
2075      PCRE_UTF8_ERR17
2076      PCRE_UTF8_ERR18
2077      PCRE_UTF8_ERR19
2078    .sp
2079    A 2-, 3-, 4-, 5-, or 6-byte character is "overlong", that is, it codes for a
2080    value that can be represented by fewer bytes, which is invalid. For example,
2081    the two bytes 0xc0, 0xae give the value 0x2e, whose correct coding uses just
2082    one byte.
2083    .sp
2084      PCRE_UTF8_ERR20
2085    .sp
2086    The two most significant bits of the first byte of a character have the binary
2087    value 0b10 (that is, the most significant bit is 1 and the second is 0). Such a
2088    byte can only validly occur as the second or subsequent byte of a multi-byte
2089    character.
2090    .sp
2091      PCRE_UTF8_ERR21
2092    .sp
2093    The first byte of a character has the value 0xfe or 0xff. These values can
2094    never occur in a valid UTF-8 string.
2095    .
2096    .
2097  .SH "EXTRACTING CAPTURED SUBSTRINGS BY NUMBER"  .SH "EXTRACTING CAPTURED SUBSTRINGS BY NUMBER"
2098  .rs  .rs
2099  .sp  .sp
# Line 1821  names are not included in the compiled c Line 2256  names are not included in the compiled c
2256  numbers. For this reason, the use of different names for subpatterns of the  numbers. For this reason, the use of different names for subpatterns of the
2257  same number causes an error at compile time.  same number causes an error at compile time.
2258  .  .
2259    .
2260  .SH "DUPLICATE SUBPATTERN NAMES"  .SH "DUPLICATE SUBPATTERN NAMES"
2261  .rs  .rs
2262  .sp  .sp
# Line 1854  fourth are pointers to variables which a Line 2290  fourth are pointers to variables which a
2290  has run, they point to the first and last entries in the name-to-number table  has run, they point to the first and last entries in the name-to-number table
2291  for the given name. The function itself returns the length of each entry, or  for the given name. The function itself returns the length of each entry, or
2292  PCRE_ERROR_NOSUBSTRING (-7) if there are none. The format of the table is  PCRE_ERROR_NOSUBSTRING (-7) if there are none. The format of the table is
2293  described above in the section entitled \fIInformation about a pattern\fP.  described above in the section entitled \fIInformation about a pattern\fP
2294    .\" HTML <a href="#infoaboutpattern">
2295    .\" </a>
2296    above.
2297    .\"
2298  Given all the relevant entries for the name, you can extract each of their  Given all the relevant entries for the name, you can extract each of their
2299  numbers, and hence the captured data, if any.  numbers, and hence the captured data, if any.
2300  .  .
# Line 1898  a compiled pattern, using a matching alg Line 2338  a compiled pattern, using a matching alg
2338  just once, and does not backtrack. This has different characteristics to the  just once, and does not backtrack. This has different characteristics to the
2339  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
2340  patterns are not supported. Nevertheless, there are times when this kind of  patterns are not supported. Nevertheless, there are times when this kind of
2341  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
2342  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
2343  .\" HREF  .\" HREF
2344  \fBpcrematching\fP  \fBpcrematching\fP
# Line 1939  Here is an example of a simple call to \ Line 2379  Here is an example of a simple call to \
2379  The unused bits of the \fIoptions\fP argument for \fBpcre_dfa_exec()\fP must be  The unused bits of the \fIoptions\fP argument for \fBpcre_dfa_exec()\fP must be
2380  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,
2381  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NOTEMPTY_ATSTART,  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NOTEMPTY_ATSTART,
2382  PCRE_NO_UTF8_CHECK, PCRE_PARTIAL_HARD, PCRE_PARTIAL_SOFT, PCRE_DFA_SHORTEST,  PCRE_NO_UTF8_CHECK, PCRE_BSR_ANYCRLF, PCRE_BSR_UNICODE, PCRE_NO_START_OPTIMIZE,
2383  and PCRE_DFA_RESTART. All but the last four of these are exactly the same as  PCRE_PARTIAL_HARD, PCRE_PARTIAL_SOFT, PCRE_DFA_SHORTEST, and PCRE_DFA_RESTART.
2384  for \fBpcre_exec()\fP, so their description is not repeated here.  All but the last four of these are exactly the same as for \fBpcre_exec()\fP,
2385    so their description is not repeated here.
2386  .sp  .sp
2387    PCRE_PARTIAL_HARD    PCRE_PARTIAL_HARD
2388    PCRE_PARTIAL_SOFT    PCRE_PARTIAL_SOFT
2389  .sp  .sp
2390  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
2391  details are slightly different. When PCRE_PARTIAL_HARD is set for  details are slightly different. When PCRE_PARTIAL_HARD is set for
# Line 1956  is converted into PCRE_ERROR_PARTIAL if Line 2397  is converted into PCRE_ERROR_PARTIAL if
2397  there have been no complete matches, but there is still at least one matching  there have been no complete matches, but there is still at least one matching
2398  possibility. The portion of the string that was inspected when the longest  possibility. The portion of the string that was inspected when the longest
2399  partial match was found is set as the first matching string in both cases.  partial match was found is set as the first matching string in both cases.
2400    There is a more detailed discussion of partial and multi-segment matching, with
2401    examples, in the
2402    .\" HREF
2403    \fBpcrepartial\fP
2404    .\"
2405    documentation.
2406  .sp  .sp
2407    PCRE_DFA_SHORTEST    PCRE_DFA_SHORTEST
2408  .sp  .sp
# Line 1977  match. There is more discussion of this Line 2424  match. There is more discussion of this
2424  .\"  .\"
2425  documentation.  documentation.
2426  .  .
2427    .
2428  .SS "Successful returns from \fBpcre_dfa_exec()\fP"  .SS "Successful returns from \fBpcre_dfa_exec()\fP"
2429  .rs  .rs
2430  .sp  .sp
# Line 2008  returns data, even though the meaning of Line 2456  returns data, even though the meaning of
2456  The strings are returned in reverse order of length; that is, the longest  The strings are returned in reverse order of length; that is, the longest
2457  matching string is given first. If there were too many matches to fit into  matching string is given first. If there were too many matches to fit into
2458  \fIovector\fP, the yield of the function is zero, and the vector is filled with  \fIovector\fP, the yield of the function is zero, and the vector is filled with
2459  the longest matches.  the longest matches. Unlike \fBpcre_exec()\fP, \fBpcre_dfa_exec()\fP can use
2460    the entire \fIovector\fP for returning matched strings.
2461    .
2462  .  .
2463  .SS "Error returns from \fBpcre_dfa_exec()\fP"  .SS "Error returns from \fBpcre_dfa_exec()\fP"
2464  .rs  .rs
# Line 2037  group. These are not supported. Line 2487  group. These are not supported.
2487    PCRE_ERROR_DFA_UMLIMIT    (-18)    PCRE_ERROR_DFA_UMLIMIT    (-18)
2488  .sp  .sp
2489  This return is given if \fBpcre_dfa_exec()\fP is called with an \fIextra\fP  This return is given if \fBpcre_dfa_exec()\fP is called with an \fIextra\fP
2490  block that contains a setting of the \fImatch_limit\fP field. This is not  block that contains a setting of the \fImatch_limit\fP or
2491  supported (it is meaningless).  \fImatch_limit_recursion\fP fields. This is not supported (these fields are
2492    meaningless for DFA matching).
2493  .sp  .sp
2494    PCRE_ERROR_DFA_WSSIZE     (-19)    PCRE_ERROR_DFA_WSSIZE     (-19)
2495  .sp  .sp
# Line 2075  Cambridge CB2 3QH, England. Line 2526  Cambridge CB2 3QH, England.
2526  .rs  .rs
2527  .sp  .sp
2528  .nf  .nf
2529  Last updated: 03 October 2009  Last updated: 06 September 2011
2530  Copyright (c) 1997-2009 University of Cambridge.  Copyright (c) 1997-2011 University of Cambridge.
2531  .fi  .fi

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