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revision 91 by nigel, Sat Feb 24 21:41:34 2007 UTC revision 312 by ph10, Wed Jan 23 18:02:23 2008 UTC
# Line 7  PCRE - Perl-compatible regular expressio Line 7  PCRE - Perl-compatible regular expressio
7  .B #include <pcre.h>  .B #include <pcre.h>
8  .PP  .PP
9  .SM  .SM
 .br  
10  .B pcre *pcre_compile(const char *\fIpattern\fP, int \fIoptions\fP,  .B pcre *pcre_compile(const char *\fIpattern\fP, int \fIoptions\fP,
11  .ti +5n  .ti +5n
12  .B const char **\fIerrptr\fP, int *\fIerroffset\fP,  .B const char **\fIerrptr\fP, int *\fIerroffset\fP,
13  .ti +5n  .ti +5n
14  .B const unsigned char *\fItableptr\fP);  .B const unsigned char *\fItableptr\fP);
15  .PP  .PP
 .br  
16  .B pcre *pcre_compile2(const char *\fIpattern\fP, int \fIoptions\fP,  .B pcre *pcre_compile2(const char *\fIpattern\fP, int \fIoptions\fP,
17  .ti +5n  .ti +5n
18  .B int *\fIerrorcodeptr\fP,  .B int *\fIerrorcodeptr\fP,
# Line 23  PCRE - Perl-compatible regular expressio Line 21  PCRE - Perl-compatible regular expressio
21  .ti +5n  .ti +5n
22  .B const unsigned char *\fItableptr\fP);  .B const unsigned char *\fItableptr\fP);
23  .PP  .PP
 .br  
24  .B pcre_extra *pcre_study(const pcre *\fIcode\fP, int \fIoptions\fP,  .B pcre_extra *pcre_study(const pcre *\fIcode\fP, int \fIoptions\fP,
25  .ti +5n  .ti +5n
26  .B const char **\fIerrptr\fP);  .B const char **\fIerrptr\fP);
27  .PP  .PP
 .br  
28  .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,"
29  .ti +5n  .ti +5n
30  .B "const char *\fIsubject\fP," int \fIlength\fP, int \fIstartoffset\fP,  .B "const char *\fIsubject\fP," int \fIlength\fP, int \fIstartoffset\fP,
31  .ti +5n  .ti +5n
32  .B int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP);  .B int \fIoptions\fP, int *\fIovector\fP, int \fIovecsize\fP);
33  .PP  .PP
 .br  
34  .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,"
35  .ti +5n  .ti +5n
36  .B "const char *\fIsubject\fP," int \fIlength\fP, int \fIstartoffset\fP,  .B "const char *\fIsubject\fP," int \fIlength\fP, int \fIstartoffset\fP,
# Line 44  PCRE - Perl-compatible regular expressio Line 39  PCRE - Perl-compatible regular expressio
39  .ti +5n  .ti +5n
40  .B int *\fIworkspace\fP, int \fIwscount\fP);  .B int *\fIworkspace\fP, int \fIwscount\fP);
41  .PP  .PP
 .br  
42  .B int pcre_copy_named_substring(const pcre *\fIcode\fP,  .B int pcre_copy_named_substring(const pcre *\fIcode\fP,
43  .ti +5n  .ti +5n
44  .B const char *\fIsubject\fP, int *\fIovector\fP,  .B const char *\fIsubject\fP, int *\fIovector\fP,
# Line 53  PCRE - Perl-compatible regular expressio Line 47  PCRE - Perl-compatible regular expressio
47  .ti +5n  .ti +5n
48  .B char *\fIbuffer\fP, int \fIbuffersize\fP);  .B char *\fIbuffer\fP, int \fIbuffersize\fP);
49  .PP  .PP
 .br  
50  .B int pcre_copy_substring(const char *\fIsubject\fP, int *\fIovector\fP,  .B int pcre_copy_substring(const char *\fIsubject\fP, int *\fIovector\fP,
51  .ti +5n  .ti +5n
52  .B int \fIstringcount\fP, int \fIstringnumber\fP, char *\fIbuffer\fP,  .B int \fIstringcount\fP, int \fIstringnumber\fP, char *\fIbuffer\fP,
53  .ti +5n  .ti +5n
54  .B int \fIbuffersize\fP);  .B int \fIbuffersize\fP);
55  .PP  .PP
 .br  
56  .B int pcre_get_named_substring(const pcre *\fIcode\fP,  .B int pcre_get_named_substring(const pcre *\fIcode\fP,
57  .ti +5n  .ti +5n
58  .B const char *\fIsubject\fP, int *\fIovector\fP,  .B const char *\fIsubject\fP, int *\fIovector\fP,
# Line 69  PCRE - Perl-compatible regular expressio Line 61  PCRE - Perl-compatible regular expressio
61  .ti +5n  .ti +5n
62  .B const char **\fIstringptr\fP);  .B const char **\fIstringptr\fP);
63  .PP  .PP
 .br  
64  .B int pcre_get_stringnumber(const pcre *\fIcode\fP,  .B int pcre_get_stringnumber(const pcre *\fIcode\fP,
65  .ti +5n  .ti +5n
66  .B const char *\fIname\fP);  .B const char *\fIname\fP);
67  .PP  .PP
 .br  
68  .B int pcre_get_stringtable_entries(const pcre *\fIcode\fP,  .B int pcre_get_stringtable_entries(const pcre *\fIcode\fP,
69  .ti +5n  .ti +5n
70  .B const char *\fIname\fP, char **\fIfirst\fP, char **\fIlast\fP);  .B const char *\fIname\fP, char **\fIfirst\fP, char **\fIlast\fP);
71  .PP  .PP
 .br  
72  .B int pcre_get_substring(const char *\fIsubject\fP, int *\fIovector\fP,  .B int pcre_get_substring(const char *\fIsubject\fP, int *\fIovector\fP,
73  .ti +5n  .ti +5n
74  .B int \fIstringcount\fP, int \fIstringnumber\fP,  .B int \fIstringcount\fP, int \fIstringnumber\fP,
75  .ti +5n  .ti +5n
76  .B const char **\fIstringptr\fP);  .B const char **\fIstringptr\fP);
77  .PP  .PP
 .br  
78  .B int pcre_get_substring_list(const char *\fIsubject\fP,  .B int pcre_get_substring_list(const char *\fIsubject\fP,
79  .ti +5n  .ti +5n
80  .B int *\fIovector\fP, int \fIstringcount\fP, "const char ***\fIlistptr\fP);"  .B int *\fIovector\fP, int \fIstringcount\fP, "const char ***\fIlistptr\fP);"
81  .PP  .PP
 .br  
82  .B void pcre_free_substring(const char *\fIstringptr\fP);  .B void pcre_free_substring(const char *\fIstringptr\fP);
83  .PP  .PP
 .br  
84  .B void pcre_free_substring_list(const char **\fIstringptr\fP);  .B void pcre_free_substring_list(const char **\fIstringptr\fP);
85  .PP  .PP
 .br  
86  .B const unsigned char *pcre_maketables(void);  .B const unsigned char *pcre_maketables(void);
87  .PP  .PP
 .br  
88  .B int pcre_fullinfo(const pcre *\fIcode\fP, "const pcre_extra *\fIextra\fP,"  .B int pcre_fullinfo(const pcre *\fIcode\fP, "const pcre_extra *\fIextra\fP,"
89  .ti +5n  .ti +5n
90  .B int \fIwhat\fP, void *\fIwhere\fP);  .B int \fIwhat\fP, void *\fIwhere\fP);
91  .PP  .PP
 .br  
92  .B int pcre_info(const pcre *\fIcode\fP, int *\fIoptptr\fP, int  .B int pcre_info(const pcre *\fIcode\fP, int *\fIoptptr\fP, int
93  .B *\fIfirstcharptr\fP);  .B *\fIfirstcharptr\fP);
94  .PP  .PP
 .br  
95  .B int pcre_refcount(pcre *\fIcode\fP, int \fIadjust\fP);  .B int pcre_refcount(pcre *\fIcode\fP, int \fIadjust\fP);
96  .PP  .PP
 .br  
97  .B int pcre_config(int \fIwhat\fP, void *\fIwhere\fP);  .B int pcre_config(int \fIwhat\fP, void *\fIwhere\fP);
98  .PP  .PP
 .br  
99  .B char *pcre_version(void);  .B char *pcre_version(void);
100  .PP  .PP
 .br  
101  .B void *(*pcre_malloc)(size_t);  .B void *(*pcre_malloc)(size_t);
102  .PP  .PP
 .br  
103  .B void (*pcre_free)(void *);  .B void (*pcre_free)(void *);
104  .PP  .PP
 .br  
105  .B void *(*pcre_stack_malloc)(size_t);  .B void *(*pcre_stack_malloc)(size_t);
106  .PP  .PP
 .br  
107  .B void (*pcre_stack_free)(void *);  .B void (*pcre_stack_free)(void *);
108  .PP  .PP
 .br  
109  .B int (*pcre_callout)(pcre_callout_block *);  .B int (*pcre_callout)(pcre_callout_block *);
110  .  .
111  .  .
112  .SH "PCRE API OVERVIEW"  .SH "PCRE API OVERVIEW"
113  .rs  .rs
114  .sp  .sp
115  PCRE has its own native API, which is described in this document. There is  PCRE has its own native API, which is described in this document. There are
116  also a set of wrapper functions that correspond to the POSIX regular expression  also some wrapper functions that correspond to the POSIX regular expression
117  API. These are described in the  API. These are described in the
118  .\" HREF  .\" HREF
119  \fBpcreposix\fP  \fBpcreposix\fP
# Line 165  distribution. The Line 140  distribution. The
140  .\" HREF  .\" HREF
141  \fBpcresample\fP  \fBpcresample\fP
142  .\"  .\"
143  documentation describes how to run it.  documentation describes how to compile and run it.
144  .P  .P
145  A second matching function, \fBpcre_dfa_exec()\fP, which is not  A second matching function, \fBpcre_dfa_exec()\fP, which is not
146  Perl-compatible, is also provided. This uses a different algorithm for the  Perl-compatible, is also provided. This uses a different algorithm for the
147  matching. The alternative algorithm finds all possible matches (at a given  matching. The alternative algorithm finds all possible matches (at a given
148  point in the subject). However, this algorithm does not return captured  point in the subject), and scans the subject just once. However, this algorithm
149  substrings. A description of the two matching algorithms and their advantages  does not return captured substrings. A description of the two matching
150  and disadvantages is given in the  algorithms and their advantages and disadvantages is given in the
151  .\" HREF  .\" HREF
152  \fBpcrematching\fP  \fBpcrematching\fP
153  .\"  .\"
# Line 243  points during a matching operation. Deta Line 218  points during a matching operation. Deta
218  documentation.  documentation.
219  .  .
220  .  .
221    .\" HTML <a name="newlines"></a>
222  .SH NEWLINES  .SH NEWLINES
223  PCRE supports three different conventions for indicating line breaks in  .rs
 strings: a single CR character, a single LF character, or the two-character  
 sequence CRLF. All three are used as "standard" by different operating systems.  
 When PCRE is built, a default can be specified. The default default is LF,  
 which is the Unix standard. When PCRE is run, the default can be overridden,  
 either when a pattern is compiled, or when it is matched.  
224  .sp  .sp
225    PCRE supports five different conventions for indicating line breaks in
226    strings: a single CR (carriage return) character, a single LF (linefeed)
227    character, the two-character sequence CRLF, any of the three preceding, or any
228    Unicode newline sequence. The Unicode newline sequences are the three just
229    mentioned, plus the single characters VT (vertical tab, U+000B), FF (formfeed,
230    U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and PS
231    (paragraph separator, U+2029).
232    .P
233    Each of the first three conventions is used by at least one operating system as
234    its standard newline sequence. When PCRE is built, a default can be specified.
235    The default default is LF, which is the Unix standard. When PCRE is run, the
236    default can be overridden, either when a pattern is compiled, or when it is
237    matched.
238    .P
239    At compile time, the newline convention can be specified by the \fIoptions\fP
240    argument of \fBpcre_compile()\fP, or it can be specified by special text at the
241    start of the pattern itself; this overrides any other settings. See the
242    .\" HREF
243    \fBpcrepattern\fP
244    .\"
245    page for details of the special character sequences.
246    .P
247  In the PCRE documentation the word "newline" is used to mean "the character or  In the PCRE documentation the word "newline" is used to mean "the character or
248  pair of characters that indicate a line break".  pair of characters that indicate a line break". The choice of newline
249    convention affects the handling of the dot, circumflex, and dollar
250    metacharacters, the handling of #-comments in /x mode, and, when CRLF is a
251    recognized line ending sequence, the match position advancement for a
252    non-anchored pattern. There is more detail about this in the
253    .\" HTML <a href="#execoptions">
254    .\" </a>
255    section on \fBpcre_exec()\fP options
256    .\"
257    below.
258    .P
259    The choice of newline convention does not affect the interpretation of
260    the \en or \er escape sequences, nor does it affect what \eR matches, which is
261    controlled in a similar way, but by separate options.
262  .  .
263  .  .
264  .SH MULTITHREADING  .SH MULTITHREADING
# Line 276  which it was compiled. Details are given Line 282  which it was compiled. Details are given
282  .\" HREF  .\" HREF
283  \fBpcreprecompile\fP  \fBpcreprecompile\fP
284  .\"  .\"
285  documentation.  documentation. However, compiling a regular expression with one version of PCRE
286    for use with a different version is not guaranteed to work and may cause
287    crashes.
288  .  .
289  .  .
290  .SH "CHECKING BUILD-TIME OPTIONS"  .SH "CHECKING BUILD-TIME OPTIONS"
# Line 308  properties is available; otherwise it is Line 316  properties is available; otherwise it is
316    PCRE_CONFIG_NEWLINE    PCRE_CONFIG_NEWLINE
317  .sp  .sp
318  The output is an integer whose value specifies the default character sequence  The output is an integer whose value specifies the default character sequence
319  that is recognized as meaning "newline". The three values that are supported  that is recognized as meaning "newline". The four values that are supported
320  are: 10 for LF, 13 for CR, and 3338 for CRLF. The default should normally be  are: 10 for LF, 13 for CR, 3338 for CRLF, -2 for ANYCRLF, and -1 for ANY. The
321  the standard sequence for your operating system.  default should normally be the standard sequence for your operating system.
322    .sp
323      PCRE_CONFIG_BSR
324    .sp
325    The output is an integer whose value indicates what character sequences the \eR
326    escape sequence matches by default. A value of 0 means that \eR matches any
327    Unicode line ending sequence; a value of 1 means that \eR matches only CR, LF,
328    or CRLF. The default can be overridden when a pattern is compiled or matched.
329  .sp  .sp
330    PCRE_CONFIG_LINK_SIZE    PCRE_CONFIG_LINK_SIZE
331  .sp  .sp
# Line 387  depend on memory location, the complete Line 402  depend on memory location, the complete
402  fully relocatable, because it may contain a copy of the \fItableptr\fP  fully relocatable, because it may contain a copy of the \fItableptr\fP
403  argument, which is an address (see below).  argument, which is an address (see below).
404  .P  .P
405  The \fIoptions\fP argument contains independent bits that affect the  The \fIoptions\fP argument contains various bit settings that affect the
406  compilation. It should be zero if no options are required. The available  compilation. It should be zero if no options are required. The available
407  options are described below. Some of them, in particular, those that are  options are described below. Some of them, in particular, those that are
408  compatible with Perl, can also be set and unset from within the pattern (see  compatible with Perl, can also be set and unset from within the pattern (see
# Line 453  facility, see the Line 468  facility, see the
468  .\"  .\"
469  documentation.  documentation.
470  .sp  .sp
471      PCRE_BSR_ANYCRLF
472      PCRE_BSR_UNICODE
473    .sp
474    These options (which are mutually exclusive) control what the \eR escape
475    sequence matches. The choice is either to match only CR, LF, or CRLF, or to
476    match any Unicode newline sequence. The default is specified when PCRE is
477    built. It can be overridden from within the pattern, or by setting an option
478    when a compiled pattern is matched.
479    .sp
480    PCRE_CASELESS    PCRE_CASELESS
481  .sp  .sp
482  If this bit is set, letters in the pattern match both upper and lower case  If this bit is set, letters in the pattern match both upper and lower case
# Line 480  If this bit is set, a dot metacharater i Line 504  If this bit is set, a dot metacharater i
504  including those that indicate newline. Without it, a dot does not match when  including those that indicate newline. Without it, a dot does not match when
505  the current position is at a newline. This option is equivalent to Perl's /s  the current position is at a newline. This option is equivalent to Perl's /s
506  option, and it can be changed within a pattern by a (?s) option setting. A  option, and it can be changed within a pattern by a (?s) option setting. A
507  negative class such as [^a] always matches newlines, independent of the setting  negative class such as [^a] always matches newline characters, independent of
508  of this option.  the setting of this option.
509  .sp  .sp
510    PCRE_DUPNAMES    PCRE_DUPNAMES
511  .sp  .sp
# Line 544  occurrences of ^ or $ in a pattern, sett Line 568  occurrences of ^ or $ in a pattern, sett
568    PCRE_NEWLINE_CR    PCRE_NEWLINE_CR
569    PCRE_NEWLINE_LF    PCRE_NEWLINE_LF
570    PCRE_NEWLINE_CRLF    PCRE_NEWLINE_CRLF
571      PCRE_NEWLINE_ANYCRLF
572      PCRE_NEWLINE_ANY
573  .sp  .sp
574  These options override the default newline definition that was chosen when PCRE  These options override the default newline definition that was chosen when PCRE
575  was built. Setting the first or the second specifies that a newline is  was built. Setting the first or the second specifies that a newline is
576  indicated by a single character (CR or LF, respectively). Setting both of them  indicated by a single character (CR or LF, respectively). Setting
577  specifies that a newline is indicated by the two-character CRLF sequence. For  PCRE_NEWLINE_CRLF specifies that a newline is indicated by the two-character
578  convenience, PCRE_NEWLINE_CRLF is defined to contain both bits. The only time  CRLF sequence. Setting PCRE_NEWLINE_ANYCRLF specifies that any of the three
579  that a line break is relevant when compiling a pattern is if PCRE_EXTENDED is  preceding sequences should be recognized. Setting PCRE_NEWLINE_ANY specifies
580  set, and an unescaped # outside a character class is encountered. This  that any Unicode newline sequence should be recognized. The Unicode newline
581  indicates a comment that lasts until after the next newline.  sequences are the three just mentioned, plus the single characters VT (vertical
582    tab, U+000B), FF (formfeed, U+000C), NEL (next line, U+0085), LS (line
583    separator, U+2028), and PS (paragraph separator, U+2029). The last two are
584    recognized only in UTF-8 mode.
585    .P
586    The newline setting in the options word uses three bits that are treated
587    as a number, giving eight possibilities. Currently only six are used (default
588    plus the five values above). This means that if you set more than one newline
589    option, the combination may or may not be sensible. For example,
590    PCRE_NEWLINE_CR with PCRE_NEWLINE_LF is equivalent to PCRE_NEWLINE_CRLF, but
591    other combinations may yield unused numbers and cause an error.
592    .P
593    The only time that a line break is specially recognized when compiling a
594    pattern is if PCRE_EXTENDED is set, and an unescaped # outside a character
595    class is encountered. This indicates a comment that lasts until after the next
596    line break sequence. In other circumstances, line break sequences are treated
597    as literal data, except that in PCRE_EXTENDED mode, both CR and LF are treated
598    as whitespace characters and are therefore ignored.
599  .P  .P
600  The newline option set at compile time becomes the default that is used for  The newline option that is set at compile time becomes the default that is used
601  \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.
602  .sp  .sp
603    PCRE_NO_AUTO_CAPTURE    PCRE_NO_AUTO_CAPTURE
604  .sp  .sp
# Line 591  page. Line 634  page.
634    PCRE_NO_UTF8_CHECK    PCRE_NO_UTF8_CHECK
635  .sp  .sp
636  When PCRE_UTF8 is set, the validity of the pattern as a UTF-8 string is  When PCRE_UTF8 is set, the validity of the pattern as a UTF-8 string is
637  automatically checked. If an invalid UTF-8 sequence of bytes is found,  automatically checked. There is a discussion about the
638  \fBpcre_compile()\fP returns an error. If you already know that your pattern is  .\" HTML <a href="pcre.html#utf8strings">
639  valid, and you want to skip this check for performance reasons, you can set the  .\" </a>
640  PCRE_NO_UTF8_CHECK option. When it is set, the effect of passing an invalid  validity of UTF-8 strings
641  UTF-8 string as a pattern is undefined. It may cause your program to crash.  .\"
642  Note that this option can also be passed to \fBpcre_exec()\fP and  in the main
643  \fBpcre_dfa_exec()\fP, to suppress the UTF-8 validity checking of subject  .\" HREF
644  strings.  \fBpcre\fP
645    .\"
646    page. If an invalid UTF-8 sequence of bytes is found, \fBpcre_compile()\fP
647    returns an error. If you already know that your pattern is valid, and you want
648    to skip this check for performance reasons, you can set the PCRE_NO_UTF8_CHECK
649    option. When it is set, the effect of passing an invalid UTF-8 string as a
650    pattern is undefined. It may cause your program to crash. Note that this option
651    can also be passed to \fBpcre_exec()\fP and \fBpcre_dfa_exec()\fP, to suppress
652    the UTF-8 validity checking of subject strings.
653  .  .
654  .  .
655  .SH "COMPILATION ERROR CODES"  .SH "COMPILATION ERROR CODES"
# Line 606  strings. Line 657  strings.
657  .sp  .sp
658  The following table lists the error codes than may be returned by  The following table lists the error codes than may be returned by
659  \fBpcre_compile2()\fP, along with the error messages that may be returned by  \fBpcre_compile2()\fP, along with the error messages that may be returned by
660  both compiling functions.  both compiling functions. As PCRE has developed, some error codes have fallen
661    out of use. To avoid confusion, they have not been re-used.
662  .sp  .sp
663     0  no error     0  no error
664     1  \e at end of pattern     1  \e at end of pattern
# Line 618  both compiling functions. Line 670  both compiling functions.
670     7  invalid escape sequence in character class     7  invalid escape sequence in character class
671     8  range out of order in character class     8  range out of order in character class
672     9  nothing to repeat     9  nothing to repeat
673    10  operand of unlimited repeat could match the empty string    10  [this code is not in use]
674    11  internal error: unexpected repeat    11  internal error: unexpected repeat
675    12  unrecognized character after (?    12  unrecognized character after (? or (?-
676    13  POSIX named classes are supported only within a class    13  POSIX named classes are supported only within a class
677    14  missing )    14  missing )
678    15  reference to non-existent subpattern    15  reference to non-existent subpattern
679    16  erroffset passed as NULL    16  erroffset passed as NULL
680    17  unknown option bit(s) set    17  unknown option bit(s) set
681    18  missing ) after comment    18  missing ) after comment
682    19  parentheses nested too deeply    19  [this code is not in use]
683    20  regular expression too large    20  regular expression is too large
684    21  failed to get memory    21  failed to get memory
685    22  unmatched parentheses    22  unmatched parentheses
686    23  internal error: code overflow    23  internal error: code overflow
# Line 637  both compiling functions. Line 689  both compiling functions.
689    26  malformed number or name after (?(    26  malformed number or name after (?(
690    27  conditional group contains more than two branches    27  conditional group contains more than two branches
691    28  assertion expected after (?(    28  assertion expected after (?(
692    29  (?R or (?digits must be followed by )    29  (?R or (?[+-]digits must be followed by )
693    30  unknown POSIX class name    30  unknown POSIX class name
694    31  POSIX collating elements are not supported    31  POSIX collating elements are not supported
695    32  this version of PCRE is not compiled with PCRE_UTF8 support    32  this version of PCRE is not compiled with PCRE_UTF8 support
696    33  spare error    33  [this code is not in use]
697    34  character value in \ex{...} sequence is too large    34  character value in \ex{...} sequence is too large
698    35  invalid condition (?(0)    35  invalid condition (?(0)
699    36  \eC not allowed in lookbehind assertion    36  \eC not allowed in lookbehind assertion
# Line 650  both compiling functions. Line 702  both compiling functions.
702    39  closing ) for (?C expected    39  closing ) for (?C expected
703    40  recursive call could loop indefinitely    40  recursive call could loop indefinitely
704    41  unrecognized character after (?P    41  unrecognized character after (?P
705    42  syntax error after (?P    42  syntax error in subpattern name (missing terminator)
706    43  two named subpatterns have the same name    43  two named subpatterns have the same name
707    44  invalid UTF-8 string    44  invalid UTF-8 string
708    45  support for \eP, \ep, and \eX has not been compiled    45  support for \eP, \ep, and \eX has not been compiled
709    46  malformed \eP or \ep sequence    46  malformed \eP or \ep sequence
710    47  unknown property name after \eP or \ep    47  unknown property name after \eP or \ep
711    48  subpattern name is too long (maximum 32 characters)    48  subpattern name is too long (maximum 32 characters)
712    49  too many named subpatterns (maximum 10,000)    49  too many named subpatterns (maximum 10000)
713    50  repeated subpattern is too long    50  [this code is not in use]
714    51  octal value is greater than \e377 (not in UTF-8 mode)    51  octal value is greater than \e377 (not in UTF-8 mode)
715      52  internal error: overran compiling workspace
716      53  internal error: previously-checked referenced subpattern not found
717      54  DEFINE group contains more than one branch
718      55  repeating a DEFINE group is not allowed
719      56  inconsistent NEWLINE options
720      57  \eg is not followed by a braced name or an optionally braced
721            non-zero number
722      58  (?+ or (?- or (?(+ or (?(- must be followed by a non-zero number
723      59  (*VERB) with an argument is not supported
724      60  (*VERB) not recognized
725      61  number is too big
726      62  subpattern name expected
727      63  digit expected after (?+
728    .sp
729    The numbers 32 and 10000 in errors 48 and 49 are defaults; different values may
730    be used if the limits were changed when PCRE was built.
731  .  .
732  .  .
733  .SH "STUDYING A PATTERN"  .SH "STUDYING A PATTERN"
# Line 719  bytes is created. Line 787  bytes is created.
787  .SH "LOCALE SUPPORT"  .SH "LOCALE SUPPORT"
788  .rs  .rs
789  .sp  .sp
790  PCRE handles caseless matching, and determines whether characters are letters  PCRE handles caseless matching, and determines whether characters are letters,
791  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
792  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
793  less than 128. Higher-valued codes never match escapes such as \ew or \ed, but  less than 128. Higher-valued codes never match escapes such as \ew or \ed, but
794  can be tested with \ep if PCRE is built with Unicode character property  can be tested with \ep if PCRE is built with Unicode character property
795  support. The use of locales with Unicode is discouraged.  support. The use of locales with Unicode is discouraged. If you are handling
796  .P  characters with codes greater than 128, you should either use UTF-8 and
797  An internal set of tables is created in the default C locale when PCRE is  Unicode, or use locales, but not try to mix the two.
798  built. This is used when the final argument of \fBpcre_compile()\fP is NULL,  .P
799  and is sufficient for many applications. An alternative set of tables can,  PCRE contains an internal set of tables that are used when the final argument
800  however, be supplied. These may be created in a different locale from the  of \fBpcre_compile()\fP is NULL. These are sufficient for many applications.
801  default. As more and more applications change to using Unicode, the need for  Normally, the internal tables recognize only ASCII characters. However, when
802  this locale support is expected to die away.  PCRE is built, it is possible to cause the internal tables to be rebuilt in the
803    default "C" locale of the local system, which may cause them to be different.
804    .P
805    The internal tables can always be overridden by tables supplied by the
806    application that calls PCRE. These may be created in a different locale from
807    the default. As more and more applications change to using Unicode, the need
808    for this locale support is expected to die away.
809  .P  .P
810  External tables are built by calling the \fBpcre_maketables()\fP function,  External tables are built by calling the \fBpcre_maketables()\fP function,
811  which has no arguments, in the relevant locale. The result can then be passed  which has no arguments, in the relevant locale. The result can then be passed
# Line 744  the following code could be used: Line 818  the following code could be used:
818    tables = pcre_maketables();    tables = pcre_maketables();
819    re = pcre_compile(..., tables);    re = pcre_compile(..., tables);
820  .sp  .sp
821    The locale name "fr_FR" is used on Linux and other Unix-like systems; if you
822    are using Windows, the name for the French locale is "french".
823    .P
824  When \fBpcre_maketables()\fP runs, the tables are built in memory that is  When \fBpcre_maketables()\fP runs, the tables are built in memory that is
825  obtained via \fBpcre_malloc\fP. It is the caller's responsibility to ensure  obtained via \fBpcre_malloc\fP. It is the caller's responsibility to ensure
826  that the memory containing the tables remains available for as long as it is  that the memory containing the tables remains available for as long as it is
# Line 827  variable. (This option used to be called Line 904  variable. (This option used to be called
904  still recognized for backwards compatibility.)  still recognized for backwards compatibility.)
905  .P  .P
906  If there is a fixed first byte, for example, from a pattern such as  If there is a fixed first byte, for example, from a pattern such as
907  (cat|cow|coyote). Otherwise, if either  (cat|cow|coyote), its value is returned. Otherwise, if either
908  .sp  .sp
909  (a) the pattern was compiled with the PCRE_MULTILINE option, and every branch  (a) the pattern was compiled with the PCRE_MULTILINE option, and every branch
910  starts with "^", or  starts with "^", or
# Line 846  table indicating a fixed set of bytes fo Line 923  table indicating a fixed set of bytes fo
923  string, a pointer to the table is returned. Otherwise NULL is returned. The  string, a pointer to the table is returned. Otherwise NULL is returned. The
924  fourth argument should point to an \fBunsigned char *\fP variable.  fourth argument should point to an \fBunsigned char *\fP variable.
925  .sp  .sp
926      PCRE_INFO_HASCRORLF
927    .sp
928    Return 1 if the pattern contains any explicit matches for CR or LF characters,
929    otherwise 0. The fourth argument should point to an \fBint\fP variable. An
930    explicit match is either a literal CR or LF character, or \er or \en.
931    .sp
932      PCRE_INFO_JCHANGED
933    .sp
934    Return 1 if the (?J) or (?-J) option setting is used in the pattern, otherwise
935    0. The fourth argument should point to an \fBint\fP variable. (?J) and
936    (?-J) set and unset the local PCRE_DUPNAMES option, respectively.
937    .sp
938    PCRE_INFO_LASTLITERAL    PCRE_INFO_LASTLITERAL
939  .sp  .sp
940  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 882  their parentheses numbers. For example, Line 971  their parentheses numbers. For example,
971  PCRE_EXTENDED is set, so white space - including newlines - is ignored):  PCRE_EXTENDED is set, so white space - including newlines - is ignored):
972  .sp  .sp
973  .\" JOIN  .\" JOIN
974    (?P<date> (?P<year>(\ed\ed)?\ed\ed) -    (?<date> (?<year>(\ed\ed)?\ed\ed) -
975    (?P<month>\ed\ed) - (?P<day>\ed\ed) )    (?<month>\ed\ed) - (?<day>\ed\ed) )
976  .sp  .sp
977  There are four named subpatterns, so the table has four entries, and each entry  There are four named subpatterns, so the table has four entries, and each entry
978  in the table is eight bytes long. The table is as follows, with non-printing  in the table is eight bytes long. The table is as follows, with non-printing
# Line 898  When writing code to extract data from n Line 987  When writing code to extract data from n
987  name-to-number map, remember that the length of the entries is likely to be  name-to-number map, remember that the length of the entries is likely to be
988  different for each compiled pattern.  different for each compiled pattern.
989  .sp  .sp
990      PCRE_INFO_OKPARTIAL
991    .sp
992    Return 1 if the pattern can be used for partial matching, otherwise 0. The
993    fourth argument should point to an \fBint\fP variable. The
994    .\" HREF
995    \fBpcrepartial\fP
996    .\"
997    documentation lists the restrictions that apply to patterns when partial
998    matching is used.
999    .sp
1000    PCRE_INFO_OPTIONS    PCRE_INFO_OPTIONS
1001  .sp  .sp
1002  Return a copy of the options with which the pattern was compiled. The fourth  Return a copy of the options with which the pattern was compiled. The fourth
1003  argument should point to an \fBunsigned long int\fP variable. These option bits  argument should point to an \fBunsigned long int\fP variable. These option bits
1004  are those specified in the call to \fBpcre_compile()\fP, modified by any  are those specified in the call to \fBpcre_compile()\fP, modified by any
1005  top-level option settings within the pattern itself.  top-level option settings at the start of the pattern itself. In other words,
1006    they are the options that will be in force when matching starts. For example,
1007    if the pattern /(?im)abc(?-i)d/ is compiled with the PCRE_EXTENDED option, the
1008    result is PCRE_CASELESS, PCRE_MULTILINE, and PCRE_EXTENDED.
1009  .P  .P
1010  A pattern is automatically anchored by PCRE if all of its top-level  A pattern is automatically anchored by PCRE if all of its top-level
1011  alternatives begin with one of the following:  alternatives begin with one of the following:
# Line 1114  called. See the Line 1216  called. See the
1216  .\"  .\"
1217  documentation for a discussion of saving compiled patterns for later use.  documentation for a discussion of saving compiled patterns for later use.
1218  .  .
1219    .\" HTML <a name="execoptions"></a>
1220  .SS "Option bits for \fBpcre_exec()\fP"  .SS "Option bits for \fBpcre_exec()\fP"
1221  .rs  .rs
1222  .sp  .sp
# Line 1128  matching position. If a pattern was comp Line 1231  matching position. If a pattern was comp
1231  to be anchored by virtue of its contents, it cannot be made unachored at  to be anchored by virtue of its contents, it cannot be made unachored at
1232  matching time.  matching time.
1233  .sp  .sp
1234      PCRE_BSR_ANYCRLF
1235      PCRE_BSR_UNICODE
1236    .sp
1237    These options (which are mutually exclusive) control what the \eR escape
1238    sequence matches. The choice is either to match only CR, LF, or CRLF, or to
1239    match any Unicode newline sequence. These options override the choice that was
1240    made or defaulted when the pattern was compiled.
1241    .sp
1242    PCRE_NEWLINE_CR    PCRE_NEWLINE_CR
1243    PCRE_NEWLINE_LF    PCRE_NEWLINE_LF
1244    PCRE_NEWLINE_CRLF    PCRE_NEWLINE_CRLF
1245      PCRE_NEWLINE_ANYCRLF
1246      PCRE_NEWLINE_ANY
1247  .sp  .sp
1248  These options override the newline definition that was chosen or defaulted when  These options override the newline definition that was chosen or defaulted when
1249  the pattern was compiled. For details, see the description \fBpcre_compile()\fP  the pattern was compiled. For details, see the description of
1250  above. During matching, the newline choice affects the behaviour of the dot,  \fBpcre_compile()\fP above. During matching, the newline choice affects the
1251  circumflex, and dollar metacharacters.  behaviour of the dot, circumflex, and dollar metacharacters. It may also alter
1252    the way the match position is advanced after a match failure for an unanchored
1253    pattern.
1254    .P
1255    When PCRE_NEWLINE_CRLF, PCRE_NEWLINE_ANYCRLF, or PCRE_NEWLINE_ANY is set, and a
1256    match attempt for an unanchored pattern fails when the current position is at a
1257    CRLF sequence, and the pattern contains no explicit matches for CR or LF
1258    characters, the match position is advanced by two characters instead of one, in
1259    other words, to after the CRLF.
1260    .P
1261    The above rule is a compromise that makes the most common cases work as
1262    expected. For example, if the pattern is .+A (and the PCRE_DOTALL option is not
1263    set), it does not match the string "\er\enA" because, after failing at the
1264    start, it skips both the CR and the LF before retrying. However, the pattern
1265    [\er\en]A does match that string, because it contains an explicit CR or LF
1266    reference, and so advances only by one character after the first failure.
1267    .P
1268    An explicit match for CR of LF is either a literal appearance of one of those
1269    characters, or one of the \er or \en escape sequences. Implicit matches such as
1270    [^X] do not count, nor does \es (which includes CR and LF in the characters
1271    that it matches).
1272    .P
1273    Notwithstanding the above, anomalous effects may still occur when CRLF is a
1274    valid newline sequence and explicit \er or \en escapes appear in the pattern.
1275  .sp  .sp
1276    PCRE_NOTBOL    PCRE_NOTBOL
1277  .sp  .sp
# Line 1178  code that demonstrates how to do this in Line 1314  code that demonstrates how to do this in
1314  When PCRE_UTF8 is set at compile time, the validity of the subject as a UTF-8  When PCRE_UTF8 is set at compile time, the validity of the subject as a UTF-8
1315  string is automatically checked when \fBpcre_exec()\fP is subsequently called.  string is automatically checked when \fBpcre_exec()\fP is subsequently called.
1316  The value of \fIstartoffset\fP is also checked to ensure that it points to the  The value of \fIstartoffset\fP is also checked to ensure that it points to the
1317  start of a UTF-8 character. If an invalid UTF-8 sequence of bytes is found,  start of a UTF-8 character. There is a discussion about the validity of UTF-8
1318  \fBpcre_exec()\fP returns the error PCRE_ERROR_BADUTF8. If \fIstartoffset\fP  strings in the
1319  contains an invalid value, PCRE_ERROR_BADUTF8_OFFSET is returned.  .\" HTML <a href="pcre.html#utf8strings">
1320    .\" </a>
1321    section on UTF-8 support
1322    .\"
1323    in the main
1324    .\" HREF
1325    \fBpcre\fP
1326    .\"
1327    page. If an invalid UTF-8 sequence of bytes is found, \fBpcre_exec()\fP returns
1328    the error PCRE_ERROR_BADUTF8. If \fIstartoffset\fP contains an invalid value,
1329    PCRE_ERROR_BADUTF8_OFFSET is returned.
1330  .P  .P
1331  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
1332  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
# Line 1336  compiled in an environment of one endian Line 1482  compiled in an environment of one endian
1482  other endianness. This is the error that PCRE gives when the magic number is  other endianness. This is the error that PCRE gives when the magic number is
1483  not present.  not present.
1484  .sp  .sp
1485    PCRE_ERROR_UNKNOWN_NODE   (-5)    PCRE_ERROR_UNKNOWN_OPCODE (-5)
1486  .sp  .sp
1487  While running the pattern match, an unknown item was encountered in the  While running the pattern match, an unknown item was encountered in the
1488  compiled pattern. This error could be caused by a bug in PCRE or by overwriting  compiled pattern. This error could be caused by a bug in PCRE or by overwriting
# Line 1362  The backtracking limit, as specified by Line 1508  The backtracking limit, as specified by
1508  \fBpcre_extra\fP structure (or defaulted) was reached. See the description  \fBpcre_extra\fP structure (or defaulted) was reached. See the description
1509  above.  above.
1510  .sp  .sp
   PCRE_ERROR_RECURSIONLIMIT (-21)  
 .sp  
 The internal recursion limit, as specified by the \fImatch_limit_recursion\fP  
 field in a \fBpcre_extra\fP structure (or defaulted) was reached. See the  
 description above.  
 .sp  
1511    PCRE_ERROR_CALLOUT        (-9)    PCRE_ERROR_CALLOUT        (-9)
1512  .sp  .sp
1513  This error is never generated by \fBpcre_exec()\fP itself. It is provided for  This error is never generated by \fBpcre_exec()\fP itself. It is provided for
# Line 1411  in PCRE or by overwriting of the compile Line 1551  in PCRE or by overwriting of the compile
1551    PCRE_ERROR_BADCOUNT       (-15)    PCRE_ERROR_BADCOUNT       (-15)
1552  .sp  .sp
1553  This error is given if the value of the \fIovecsize\fP argument is negative.  This error is given if the value of the \fIovecsize\fP argument is negative.
1554    .sp
1555      PCRE_ERROR_RECURSIONLIMIT (-21)
1556    .sp
1557    The internal recursion limit, as specified by the \fImatch_limit_recursion\fP
1558    field in a \fBpcre_extra\fP structure (or defaulted) was reached. See the
1559    description above.
1560    .sp
1561      PCRE_ERROR_BADNEWLINE     (-23)
1562    .sp
1563    An invalid combination of PCRE_NEWLINE_\fIxxx\fP options was given.
1564    .P
1565    Error numbers -16 to -20 and -22 are not used by \fBpcre_exec()\fP.
1566  .  .
1567  .  .
1568  .SH "EXTRACTING CAPTURED SUBSTRINGS BY NUMBER"  .SH "EXTRACTING CAPTURED SUBSTRINGS BY NUMBER"
# Line 1422  This error is given if the value of the Line 1574  This error is given if the value of the
1574  .ti +5n  .ti +5n
1575  .B int \fIbuffersize\fP);  .B int \fIbuffersize\fP);
1576  .PP  .PP
 .br  
1577  .B int pcre_get_substring(const char *\fIsubject\fP, int *\fIovector\fP,  .B int pcre_get_substring(const char *\fIsubject\fP, int *\fIovector\fP,
1578  .ti +5n  .ti +5n
1579  .B int \fIstringcount\fP, int \fIstringnumber\fP,  .B int \fIstringcount\fP, int \fIstringnumber\fP,
1580  .ti +5n  .ti +5n
1581  .B const char **\fIstringptr\fP);  .B const char **\fIstringptr\fP);
1582  .PP  .PP
 .br  
1583  .B int pcre_get_substring_list(const char *\fIsubject\fP,  .B int pcre_get_substring_list(const char *\fIsubject\fP,
1584  .ti +5n  .ti +5n
1585  .B int *\fIovector\fP, int \fIstringcount\fP, "const char ***\fIlistptr\fP);"  .B int *\fIovector\fP, int \fIstringcount\fP, "const char ***\fIlistptr\fP);"
# Line 1468  the string is placed in \fIbuffer\fP, wh Line 1618  the string is placed in \fIbuffer\fP, wh
1618  \fIbuffersize\fP, while for \fBpcre_get_substring()\fP a new block of memory is  \fIbuffersize\fP, while for \fBpcre_get_substring()\fP a new block of memory is
1619  obtained via \fBpcre_malloc\fP, and its address is returned via  obtained via \fBpcre_malloc\fP, and its address is returned via
1620  \fIstringptr\fP. The yield of the function is the length of the string, not  \fIstringptr\fP. The yield of the function is the length of the string, not
1621  including the terminating zero, or one of  including the terminating zero, or one of these error codes:
1622  .sp  .sp
1623    PCRE_ERROR_NOMEMORY       (-6)    PCRE_ERROR_NOMEMORY       (-6)
1624  .sp  .sp
# Line 1484  and builds a list of pointers to them. A Line 1634  and builds a list of pointers to them. A
1634  memory that is obtained via \fBpcre_malloc\fP. The address of the memory block  memory that is obtained via \fBpcre_malloc\fP. The address of the memory block
1635  is returned via \fIlistptr\fP, which is also the start of the list of string  is returned via \fIlistptr\fP, which is also the start of the list of string
1636  pointers. The end of the list is marked by a NULL pointer. The yield of the  pointers. The end of the list is marked by a NULL pointer. The yield of the
1637  function is zero if all went well, or  function is zero if all went well, or the error code
1638  .sp  .sp
1639    PCRE_ERROR_NOMEMORY       (-6)    PCRE_ERROR_NOMEMORY       (-6)
1640  .sp  .sp
# Line 1515  provided. Line 1665  provided.
1665  .ti +5n  .ti +5n
1666  .B const char *\fIname\fP);  .B const char *\fIname\fP);
1667  .PP  .PP
 .br  
1668  .B int pcre_copy_named_substring(const pcre *\fIcode\fP,  .B int pcre_copy_named_substring(const pcre *\fIcode\fP,
1669  .ti +5n  .ti +5n
1670  .B const char *\fIsubject\fP, int *\fIovector\fP,  .B const char *\fIsubject\fP, int *\fIovector\fP,
# Line 1524  provided. Line 1673  provided.
1673  .ti +5n  .ti +5n
1674  .B char *\fIbuffer\fP, int \fIbuffersize\fP);  .B char *\fIbuffer\fP, int \fIbuffersize\fP);
1675  .PP  .PP
 .br  
1676  .B int pcre_get_named_substring(const pcre *\fIcode\fP,  .B int pcre_get_named_substring(const pcre *\fIcode\fP,
1677  .ti +5n  .ti +5n
1678  .B const char *\fIsubject\fP, int *\fIovector\fP,  .B const char *\fIsubject\fP, int *\fIovector\fP,
# Line 1536  provided. Line 1684  provided.
1684  To extract a substring by name, you first have to find associated number.  To extract a substring by name, you first have to find associated number.
1685  For example, for this pattern  For example, for this pattern
1686  .sp  .sp
1687    (a+)b(?P<xxx>\ed+)...    (a+)b(?<xxx>\ed+)...
1688  .sp  .sp
1689  the number of the subpattern called "xxx" is 2. If the name is known to be  the number of the subpattern called "xxx" is 2. If the name is known to be
1690  unique (PCRE_DUPNAMES was not set), you can find the number from the name by  unique (PCRE_DUPNAMES was not set), you can find the number from the name by
# Line 1560  pattern. This is needed in order to gain Line 1708  pattern. This is needed in order to gain
1708  translation table.  translation table.
1709  .P  .P
1710  These functions call \fBpcre_get_stringnumber()\fP, and if it succeeds, they  These functions call \fBpcre_get_stringnumber()\fP, and if it succeeds, they
1711  then call \fIpcre_copy_substring()\fP or \fIpcre_get_substring()\fP, as  then call \fBpcre_copy_substring()\fP or \fBpcre_get_substring()\fP, as
1712  appropriate.  appropriate. \fBNOTE:\fP If PCRE_DUPNAMES is set and there are duplicate names,
1713    the behaviour may not be what you want (see the next section).
1714  .  .
1715  .  .
1716  .SH "DUPLICATE SUBPATTERN NAMES"  .SH "DUPLICATE SUBPATTERN NAMES"
# Line 1578  example is shown in the Line 1727  example is shown in the
1727  .\" HREF  .\" HREF
1728  \fBpcrepattern\fP  \fBpcrepattern\fP
1729  .\"  .\"
1730  documentation. When duplicates are present, \fBpcre_copy_named_substring()\fP  documentation.
1731  and \fBpcre_get_named_substring()\fP return the first substring corresponding  .P
1732  to the given name that is set. If none are set, an empty string is returned.  When duplicates are present, \fBpcre_copy_named_substring()\fP and
1733  The \fBpcre_get_stringnumber()\fP function returns one of the numbers that are  \fBpcre_get_named_substring()\fP return the first substring corresponding to
1734  associated with the name, but it is not defined which it is.  the given name that is set. If none are set, PCRE_ERROR_NOSUBSTRING (-7) is
1735  .sp  returned; no data is returned. The \fBpcre_get_stringnumber()\fP function
1736    returns one of the numbers that are associated with the name, but it is not
1737    defined which it is.
1738    .P
1739  If you want to get full details of all captured substrings for a given name,  If you want to get full details of all captured substrings for a given name,
1740  you must use the \fBpcre_get_stringtable_entries()\fP function. The first  you must use the \fBpcre_get_stringtable_entries()\fP function. The first
1741  argument is the compiled pattern, and the second is the name. The third and  argument is the compiled pattern, and the second is the name. The third and
1742  fourth are pointers to variables which are updated by the function. After it  fourth are pointers to variables which are updated by the function. After it
1743  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
1744  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
1745  PCRE_ERROR_NOSUBSTRING if there are none. The format of the table is described  PCRE_ERROR_NOSUBSTRING (-7) if there are none. The format of the table is
1746  above in the section entitled \fIInformation about a pattern\fP. Given all the  described above in the section entitled \fIInformation about a pattern\fP.
1747  relevant entries for the name, you can extract each of their numbers, and hence  Given all the relevant entries for the name, you can extract each of their
1748  the captured data, if any.  numbers, and hence the captured data, if any.
1749  .  .
1750  .  .
1751  .SH "FINDING ALL POSSIBLE MATCHES"  .SH "FINDING ALL POSSIBLE MATCHES"
# Line 1631  will yield PCRE_ERROR_NOMATCH. Line 1783  will yield PCRE_ERROR_NOMATCH.
1783  .B int *\fIworkspace\fP, int \fIwscount\fP);  .B int *\fIworkspace\fP, int \fIwscount\fP);
1784  .P  .P
1785  The function \fBpcre_dfa_exec()\fP is called to match a subject string against  The function \fBpcre_dfa_exec()\fP is called to match a subject string against
1786  a compiled pattern, using a "DFA" matching algorithm. This has different  a compiled pattern, using a matching algorithm that scans the subject string
1787  characteristics to the normal algorithm, and is not compatible with Perl. Some  just once, and does not backtrack. This has different characteristics to the
1788  of the features of PCRE patterns are not supported. Nevertheless, there are  normal algorithm, and is not compatible with Perl. Some of the features of PCRE
1789  times when this kind of matching can be useful. For a discussion of the two  patterns are not supported. Nevertheless, there are times when this kind of
1790  matching algorithms, see the  matching can be useful. For a discussion of the two matching algorithms, see
1791    the
1792  .\" HREF  .\" HREF
1793  \fBpcrematching\fP  \fBpcrematching\fP
1794  .\"  .\"
# Line 1691  matching string. Line 1844  matching string.
1844    PCRE_DFA_SHORTEST    PCRE_DFA_SHORTEST
1845  .sp  .sp
1846  Setting the PCRE_DFA_SHORTEST option causes the matching algorithm to stop as  Setting the PCRE_DFA_SHORTEST option causes the matching algorithm to stop as
1847  soon as it has found one match. Because of the way the DFA algorithm works,  soon as it has found one match. Because of the way the alternative algorithm
1848  this is necessarily the shortest possible match at the first possible matching  works, this is necessarily the shortest possible match at the first possible
1849  point in the subject string.  matching point in the subject string.
1850  .sp  .sp
1851    PCRE_DFA_RESTART    PCRE_DFA_RESTART
1852  .sp  .sp
# Line 1732  the three matched strings are Line 1885  the three matched strings are
1885  On success, the yield of the function is a number greater than zero, which is  On success, the yield of the function is a number greater than zero, which is
1886  the number of matched substrings. The substrings themselves are returned in  the number of matched substrings. The substrings themselves are returned in
1887  \fIovector\fP. Each string uses two elements; the first is the offset to the  \fIovector\fP. Each string uses two elements; the first is the offset to the
1888  start, and the second is the offset to the end. All the strings have the same  start, and the second is the offset to the end. In fact, all the strings have
1889  start offset. (Space could have been saved by giving this only once, but it was  the same start offset. (Space could have been saved by giving this only once,
1890  decided to retain some compatibility with the way \fBpcre_exec()\fP returns  but it was decided to retain some compatibility with the way \fBpcre_exec()\fP
1891  data, even though the meaning of the strings is different.)  returns data, even though the meaning of the strings is different.)
1892  .P  .P
1893  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
1894  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
# Line 1762  that it does not support, for instance, Line 1915  that it does not support, for instance,
1915  .sp  .sp
1916    PCRE_ERROR_DFA_UCOND      (-17)    PCRE_ERROR_DFA_UCOND      (-17)
1917  .sp  .sp
1918  This return is given if \fBpcre_dfa_exec()\fP encounters a condition item in a  This return is given if \fBpcre_dfa_exec()\fP encounters a condition item that
1919  pattern that uses a back reference for the condition. This is not supported.  uses a back reference for the condition, or a test for recursion in a specific
1920    group. These are not supported.
1921  .sp  .sp
1922    PCRE_ERROR_DFA_UMLIMIT    (-18)    PCRE_ERROR_DFA_UMLIMIT    (-18)
1923  .sp  .sp
# Line 1782  When a recursive subpattern is processed Line 1936  When a recursive subpattern is processed
1936  recursively, using private vectors for \fIovector\fP and \fIworkspace\fP. This  recursively, using private vectors for \fIovector\fP and \fIworkspace\fP. This
1937  error is given if the output vector is not large enough. This should be  error is given if the output vector is not large enough. This should be
1938  extremely rare, as a vector of size 1000 is used.  extremely rare, as a vector of size 1000 is used.
1939  .P  .
1940  .in 0  .
1941  Last updated: 08 June 2006  .SH "SEE ALSO"
1942  .br  .rs
1943  Copyright (c) 1997-2006 University of Cambridge.  .sp
1944    \fBpcrebuild\fP(3), \fBpcrecallout\fP(3), \fBpcrecpp(3)\fP(3),
1945    \fBpcrematching\fP(3), \fBpcrepartial\fP(3), \fBpcreposix\fP(3),
1946    \fBpcreprecompile\fP(3), \fBpcresample\fP(3), \fBpcrestack\fP(3).
1947    .
1948    .
1949    .SH AUTHOR
1950    .rs
1951    .sp
1952    .nf
1953    Philip Hazel
1954    University Computing Service
1955    Cambridge CB2 3QH, England.
1956    .fi
1957    .
1958    .
1959    .SH REVISION
1960    .rs
1961    .sp
1962    .nf
1963    Last updated: 23 January 2008
1964    Copyright (c) 1997-2008 University of Cambridge.
1965    .fi

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