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revision 79 by nigel, Sat Feb 24 21:40:52 2007 UTC revision 226 by ph10, Tue Aug 21 11:46:08 2007 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
68  .br  .B int pcre_get_stringtable_entries(const pcre *\fIcode\fP,
69    .ti +5n
70    .B const char *\fIname\fP, char **\fIfirst\fP, char **\fIlast\fP);
71    .PP
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 164  documentation describes how to run it. Line 144  documentation describes how to 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. This allows it to find all possible matches (at a given point in the  matching. The alternative algorithm finds all possible matches (at a given
148  subject), not just one. 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 183  matched by \fBpcre_exec()\fP. They are: Line 163  matched by \fBpcre_exec()\fP. They are:
163    \fBpcre_get_named_substring()\fP    \fBpcre_get_named_substring()\fP
164    \fBpcre_get_substring_list()\fP    \fBpcre_get_substring_list()\fP
165    \fBpcre_get_stringnumber()\fP    \fBpcre_get_stringnumber()\fP
166      \fBpcre_get_stringtable_entries()\fP
167  .sp  .sp
168  \fBpcre_free_substring()\fP and \fBpcre_free_substring_list()\fP are also  \fBpcre_free_substring()\fP and \fBpcre_free_substring_list()\fP are also
169  provided, to free the memory used for extracted strings.  provided, to free the memory used for extracted strings.
# Line 212  should be done before calling any PCRE f Line 193  should be done before calling any PCRE f
193  The global variables \fBpcre_stack_malloc\fP and \fBpcre_stack_free\fP are also  The global variables \fBpcre_stack_malloc\fP and \fBpcre_stack_free\fP are also
194  indirections to memory management functions. These special functions are used  indirections to memory management functions. These special functions are used
195  only when PCRE is compiled to use the heap for remembering data, instead of  only when PCRE is compiled to use the heap for remembering data, instead of
196  recursive function calls, when running the \fBpcre_exec()\fP function. This is  recursive function calls, when running the \fBpcre_exec()\fP function. See the
197  a non-standard way of building PCRE, for use in environments that have limited  .\" HREF
198  stacks. Because of the greater use of memory management, it runs more slowly.  \fBpcrebuild\fP
199  Separate functions are provided so that special-purpose external code can be  .\"
200  used for this case. When used, these functions are always called in a  documentation for details of how to do this. It is a non-standard way of
201  stack-like manner (last obtained, first freed), and always for memory blocks of  building PCRE, for use in environments that have limited stacks. Because of the
202  the same size.  greater use of memory management, it runs more slowly. Separate functions are
203    provided so that special-purpose external code can be used for this case. When
204    used, these functions are always called in a stack-like manner (last obtained,
205    first freed), and always for memory blocks of the same size. There is a
206    discussion about PCRE's stack usage in the
207    .\" HREF
208    \fBpcrestack\fP
209    .\"
210    documentation.
211  .P  .P
212  The global variable \fBpcre_callout\fP initially contains NULL. It can be set  The global variable \fBpcre_callout\fP initially contains NULL. It can be set
213  by the caller to a "callout" function, which PCRE will then call at specified  by the caller to a "callout" function, which PCRE will then call at specified
# Line 229  points during a matching operation. Deta Line 218  points during a matching operation. Deta
218  documentation.  documentation.
219  .  .
220  .  .
221    .SH NEWLINES
222    .rs
223    .sp
224    PCRE supports five different conventions for indicating line breaks in
225    strings: a single CR (carriage return) character, a single LF (linefeed)
226    character, the two-character sequence CRLF, any of the three preceding, or any
227    Unicode newline sequence. The Unicode newline sequences are the three just
228    mentioned, plus the single characters VT (vertical tab, U+000B), FF (formfeed,
229    U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and PS
230    (paragraph separator, U+2029).
231    .P
232    Each of the first three conventions is used by at least one operating system as
233    its standard newline sequence. When PCRE is built, a default can be specified.
234    The default default is LF, which is the Unix standard. When PCRE is run, the
235    default can be overridden, either when a pattern is compiled, or when it is
236    matched.
237    .P
238    In the PCRE documentation the word "newline" is used to mean "the character or
239    pair of characters that indicate a line break". The choice of newline
240    convention affects the handling of the dot, circumflex, and dollar
241    metacharacters, the handling of #-comments in /x mode, and, when CRLF is a
242    recognized line ending sequence, the match position advancement for a
243    non-anchored pattern. There is more detail about this in the
244    .\" HTML <a href="#execoptions">
245    .\" </a>
246    section on \fBpcre_exec()\fP options
247    .\"
248    below. The choice of newline convention does not affect the interpretation of
249    the \en or \er escape sequences.
250    .
251    .
252  .SH MULTITHREADING  .SH MULTITHREADING
253  .rs  .rs
254  .sp  .sp
# Line 250  which it was compiled. Details are given Line 270  which it was compiled. Details are given
270  .\" HREF  .\" HREF
271  \fBpcreprecompile\fP  \fBpcreprecompile\fP
272  .\"  .\"
273  documentation.  documentation. However, compiling a regular expression with one version of PCRE
274    for use with a different version is not guaranteed to work and may cause
275    crashes.
276  .  .
277  .  .
278  .SH "CHECKING BUILD-TIME OPTIONS"  .SH "CHECKING BUILD-TIME OPTIONS"
# Line 281  properties is available; otherwise it is Line 303  properties is available; otherwise it is
303  .sp  .sp
304    PCRE_CONFIG_NEWLINE    PCRE_CONFIG_NEWLINE
305  .sp  .sp
306  The output is an integer that is set to the value of the code that is used for  The output is an integer whose value specifies the default character sequence
307  the newline character. It is either linefeed (10) or carriage return (13), and  that is recognized as meaning "newline". The four values that are supported
308  should normally be the standard character for your operating system.  are: 10 for LF, 13 for CR, 3338 for CRLF, -2 for ANYCRLF, and -1 for ANY. The
309    default should normally be the standard sequence for your operating system.
310  .sp  .sp
311    PCRE_CONFIG_LINK_SIZE    PCRE_CONFIG_LINK_SIZE
312  .sp  .sp
# Line 309  The output is an integer that gives the Line 332  The output is an integer that gives the
332  internal matching function calls in a \fBpcre_exec()\fP execution. Further  internal matching function calls in a \fBpcre_exec()\fP execution. Further
333  details are given with \fBpcre_exec()\fP below.  details are given with \fBpcre_exec()\fP below.
334  .sp  .sp
335      PCRE_CONFIG_MATCH_LIMIT_RECURSION
336    .sp
337    The output is an integer that gives the default limit for the depth of
338    recursion when calling the internal matching function in a \fBpcre_exec()\fP
339    execution. Further details are given with \fBpcre_exec()\fP below.
340    .sp
341    PCRE_CONFIG_STACKRECURSE    PCRE_CONFIG_STACKRECURSE
342  .sp  .sp
343  The output is an integer that is set to one if internal recursion when running  The output is an integer that is set to one if internal recursion when running
# Line 347  The pattern is a C string terminated by Line 376  The pattern is a C string terminated by
376  via \fBpcre_malloc\fP is returned. This contains the compiled code and related  via \fBpcre_malloc\fP is returned. This contains the compiled code and related
377  data. The \fBpcre\fP type is defined for the returned block; this is a typedef  data. The \fBpcre\fP type is defined for the returned block; this is a typedef
378  for a structure whose contents are not externally defined. It is up to the  for a structure whose contents are not externally defined. It is up to the
379  caller to free the memory when it is no longer required.  caller to free the memory (via \fBpcre_free\fP) when it is no longer required.
380  .P  .P
381  Although the compiled code of a PCRE regex is relocatable, that is, it does not  Although the compiled code of a PCRE regex is relocatable, that is, it does not
382  depend on memory location, the complete \fBpcre\fP data block is not  depend on memory location, the complete \fBpcre\fP data block is not
383  fully relocatable, because it may contain a copy of the \fItableptr\fP  fully relocatable, because it may contain a copy of the \fItableptr\fP
384  argument, which is an address (see below).  argument, which is an address (see below).
385  .P  .P
386  The \fIoptions\fP argument contains independent bits that affect the  The \fIoptions\fP argument contains various bit settings that affect the
387  compilation. It should be zero if no options are required. The available  compilation. It should be zero if no options are required. The available
388  options are described below. Some of them, in particular, those that are  options are described below. Some of them, in particular, those that are
389  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 364  the detailed description in the Line 393  the detailed description in the
393  .\"  .\"
394  documentation). For these options, the contents of the \fIoptions\fP argument  documentation). For these options, the contents of the \fIoptions\fP argument
395  specifies their initial settings at the start of compilation and execution. The  specifies their initial settings at the start of compilation and execution. The
396  PCRE_ANCHORED option can be set at the time of matching as well as at compile  PCRE_ANCHORED and PCRE_NEWLINE_\fIxxx\fP options can be set at the time of
397  time.  matching as well as at compile time.
398  .P  .P
399  If \fIerrptr\fP is NULL, \fBpcre_compile()\fP returns NULL immediately.  If \fIerrptr\fP is NULL, \fBpcre_compile()\fP returns NULL immediately.
400  Otherwise, if compilation of a pattern fails, \fBpcre_compile()\fP returns  Otherwise, if compilation of a pattern fails, \fBpcre_compile()\fP returns
401  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
402  error message. The offset from the start of the pattern to the character where  error message. This is a static string that is part of the library. You must
403  the error was discovered is placed in the variable pointed to by  not try to free it. The offset from the start of the pattern to the character
404    where the error was discovered is placed in the variable pointed to by
405  \fIerroffset\fP, which must not be NULL. If it is, an immediate error is given.  \fIerroffset\fP, which must not be NULL. If it is, an immediate error is given.
406  .P  .P
407  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
# Line 435  with UTF-8 support. Line 465  with UTF-8 support.
465  .sp  .sp
466  If this bit is set, a dollar metacharacter in the pattern matches only at the  If this bit is set, a dollar metacharacter in the pattern matches only at the
467  end of the subject string. Without this option, a dollar also matches  end of the subject string. Without this option, a dollar also matches
468  immediately before the final character if it is a newline (but not before any  immediately before a newline at the end of the string (but not before any other
469  other newlines). The PCRE_DOLLAR_ENDONLY option is ignored if PCRE_MULTILINE is  newlines). The PCRE_DOLLAR_ENDONLY option is ignored if PCRE_MULTILINE is set.
470  set. There is no equivalent to this option in Perl, and no way to set it within  There is no equivalent to this option in Perl, and no way to set it within a
471  a pattern.  pattern.
472  .sp  .sp
473    PCRE_DOTALL    PCRE_DOTALL
474  .sp  .sp
475  If this bit is set, a dot metacharater in the pattern matches all characters,  If this bit is set, a dot metacharater in the pattern matches all characters,
476  including newlines. Without it, newlines are excluded. This option is  including those that indicate newline. Without it, a dot does not match when
477  equivalent to Perl's /s option, and it can be changed within a pattern by a  the current position is at a newline. This option is equivalent to Perl's /s
478  (?s) option setting. A negative class such as [^a] always matches a newline  option, and it can be changed within a pattern by a (?s) option setting. A
479  character, independent of the setting of this option.  negative class such as [^a] always matches newline characters, independent of
480    the setting of this option.
481    .sp
482      PCRE_DUPNAMES
483    .sp
484    If this bit is set, names used to identify capturing subpatterns need not be
485    unique. This can be helpful for certain types of pattern when it is known that
486    only one instance of the named subpattern can ever be matched. There are more
487    details of named subpatterns below; see also the
488    .\" HREF
489    \fBpcrepattern\fP
490    .\"
491    documentation.
492  .sp  .sp
493    PCRE_EXTENDED    PCRE_EXTENDED
494  .sp  .sp
495  If this bit is set, whitespace data characters in the pattern are totally  If this bit is set, whitespace data characters in the pattern are totally
496  ignored except when escaped or inside a character class. Whitespace does not  ignored except when escaped or inside a character class. Whitespace does not
497  include the VT character (code 11). In addition, characters between an  include the VT character (code 11). In addition, characters between an
498  unescaped # outside a character class and the next newline character,  unescaped # outside a character class and the next newline, inclusive, are also
499  inclusive, are also ignored. This is equivalent to Perl's /x option, and it can  ignored. This is equivalent to Perl's /x option, and it can be changed within a
500  be changed within a pattern by a (?x) option setting.  pattern by a (?x) option setting.
501  .P  .P
502  This option makes it possible to include comments inside complicated patterns.  This option makes it possible to include comments inside complicated patterns.
503  Note, however, that this applies only to data characters. Whitespace characters  Note, however, that this applies only to data characters. Whitespace characters
# Line 469  that is incompatible with Perl, but it i Line 511  that is incompatible with Perl, but it i
511  set, any backslash in a pattern that is followed by a letter that has no  set, any backslash in a pattern that is followed by a letter that has no
512  special meaning causes an error, thus reserving these combinations for future  special meaning causes an error, thus reserving these combinations for future
513  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
514  special meaning is treated as a literal. There are at present no other features  special meaning is treated as a literal. (Perl can, however, be persuaded to
515  controlled by this option. It can also be set by a (?X) option setting within a  give a warning for this.) There are at present no other features controlled by
516  pattern.  this option. It can also be set by a (?X) option setting within a pattern.
517  .sp  .sp
518    PCRE_FIRSTLINE    PCRE_FIRSTLINE
519  .sp  .sp
520  If this option is set, an unanchored pattern is required to match before or at  If this option is set, an unanchored pattern is required to match before or at
521  the first newline character in the subject string, though the matched text may  the first newline in the subject string, though the matched text may continue
522  continue over the newline.  over the newline.
523  .sp  .sp
524    PCRE_MULTILINE    PCRE_MULTILINE
525  .sp  .sp
# Line 489  terminating newline (unless PCRE_DOLLAR_ Line 531  terminating newline (unless PCRE_DOLLAR_
531  Perl.  Perl.
532  .P  .P
533  When PCRE_MULTILINE it is set, the "start of line" and "end of line" constructs  When PCRE_MULTILINE it is set, the "start of line" and "end of line" constructs
534  match immediately following or immediately before any newline in the subject  match immediately following or immediately before internal newlines in the
535  string, respectively, as well as at the very start and end. This is equivalent  subject string, respectively, as well as at the very start and end. This is
536  to Perl's /m option, and it can be changed within a pattern by a (?m) option  equivalent to Perl's /m option, and it can be changed within a pattern by a
537  setting. If there are no "\en" characters in a subject string, or no  (?m) option setting. If there are no newlines in a subject string, or no
538  occurrences of ^ or $ in a pattern, setting PCRE_MULTILINE has no effect.  occurrences of ^ or $ in a pattern, setting PCRE_MULTILINE has no effect.
539  .sp  .sp
540      PCRE_NEWLINE_CR
541      PCRE_NEWLINE_LF
542      PCRE_NEWLINE_CRLF
543      PCRE_NEWLINE_ANYCRLF
544      PCRE_NEWLINE_ANY
545    .sp
546    These options override the default newline definition that was chosen when PCRE
547    was built. Setting the first or the second specifies that a newline is
548    indicated by a single character (CR or LF, respectively). Setting
549    PCRE_NEWLINE_CRLF specifies that a newline is indicated by the two-character
550    CRLF sequence. Setting PCRE_NEWLINE_ANYCRLF specifies that any of the three
551    preceding sequences should be recognized. Setting PCRE_NEWLINE_ANY specifies
552    that any Unicode newline sequence should be recognized. The Unicode newline
553    sequences are the three just mentioned, plus the single characters VT (vertical
554    tab, U+000B), FF (formfeed, U+000C), NEL (next line, U+0085), LS (line
555    separator, U+2028), and PS (paragraph separator, U+2029). The last two are
556    recognized only in UTF-8 mode.
557    .P
558    The newline setting in the options word uses three bits that are treated
559    as a number, giving eight possibilities. Currently only six are used (default
560    plus the five values above). This means that if you set more than one newline
561    option, the combination may or may not be sensible. For example,
562    PCRE_NEWLINE_CR with PCRE_NEWLINE_LF is equivalent to PCRE_NEWLINE_CRLF, but
563    other combinations may yield unused numbers and cause an error.
564    .P
565    The only time that a line break is specially recognized when compiling a
566    pattern is if PCRE_EXTENDED is set, and an unescaped # outside a character
567    class is encountered. This indicates a comment that lasts until after the next
568    line break sequence. In other circumstances, line break sequences are treated
569    as literal data, except that in PCRE_EXTENDED mode, both CR and LF are treated
570    as whitespace characters and are therefore ignored.
571    .P
572    The newline option that is set at compile time becomes the default that is used
573    for \fBpcre_exec()\fP and \fBpcre_dfa_exec()\fP, but it can be overridden.
574    .sp
575    PCRE_NO_AUTO_CAPTURE    PCRE_NO_AUTO_CAPTURE
576  .sp  .sp
577  If this option is set, it disables the use of numbered capturing parentheses in  If this option is set, it disables the use of numbered capturing parentheses in
# Line 529  page. Line 606  page.
606    PCRE_NO_UTF8_CHECK    PCRE_NO_UTF8_CHECK
607  .sp  .sp
608  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
609  automatically checked. If an invalid UTF-8 sequence of bytes is found,  automatically checked. There is a discussion about the
610  \fBpcre_compile()\fP returns an error. If you already know that your pattern is  .\" HTML <a href="pcre.html#utf8strings">
611  valid, and you want to skip this check for performance reasons, you can set the  .\" </a>
612  PCRE_NO_UTF8_CHECK option. When it is set, the effect of passing an invalid  validity of UTF-8 strings
613  UTF-8 string as a pattern is undefined. It may cause your program to crash.  .\"
614  Note that this option can also be passed to \fBpcre_exec()\fP and  in the main
615  \fBpcre_dfa_exec()\fP, to suppress the UTF-8 validity checking of subject  .\" HREF
616  strings.  \fBpcre\fP
617    .\"
618    page. If an invalid UTF-8 sequence of bytes is found, \fBpcre_compile()\fP
619    returns an error. If you already know that your pattern is valid, and you want
620    to skip this check for performance reasons, you can set the PCRE_NO_UTF8_CHECK
621    option. When it is set, the effect of passing an invalid UTF-8 string as a
622    pattern is undefined. It may cause your program to crash. Note that this option
623    can also be passed to \fBpcre_exec()\fP and \fBpcre_dfa_exec()\fP, to suppress
624    the UTF-8 validity checking of subject strings.
625  .  .
626  .  .
627  .SH "COMPILATION ERROR CODES"  .SH "COMPILATION ERROR CODES"
# Line 544  strings. Line 629  strings.
629  .sp  .sp
630  The following table lists the error codes than may be returned by  The following table lists the error codes than may be returned by
631  \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
632  both compiling functions.  both compiling functions. As PCRE has developed, some error codes have fallen
633    out of use. To avoid confusion, they have not been re-used.
634  .sp  .sp
635     0  no error     0  no error
636     1  \e at end of pattern     1  \e at end of pattern
# Line 556  both compiling functions. Line 642  both compiling functions.
642     7  invalid escape sequence in character class     7  invalid escape sequence in character class
643     8  range out of order in character class     8  range out of order in character class
644     9  nothing to repeat     9  nothing to repeat
645    10  operand of unlimited repeat could match the empty string    10  [this code is not in use]
646    11  internal error: unexpected repeat    11  internal error: unexpected repeat
647    12  unrecognized character after (?    12  unrecognized character after (?
648    13  POSIX named classes are supported only within a class    13  POSIX named classes are supported only within a class
# Line 565  both compiling functions. Line 651  both compiling functions.
651    16  erroffset passed as NULL    16  erroffset passed as NULL
652    17  unknown option bit(s) set    17  unknown option bit(s) set
653    18  missing ) after comment    18  missing ) after comment
654    19  parentheses nested too deeply    19  [this code is not in use]
655    20  regular expression too large    20  regular expression too large
656    21  failed to get memory    21  failed to get memory
657    22  unmatched parentheses    22  unmatched parentheses
658    23  internal error: code overflow    23  internal error: code overflow
659    24  unrecognized character after (?<    24  unrecognized character after (?<
660    25  lookbehind assertion is not fixed length    25  lookbehind assertion is not fixed length
661    26  malformed number after (?(    26  malformed number or name after (?(
662    27  conditional group contains more than two branches    27  conditional group contains more than two branches
663    28  assertion expected after (?(    28  assertion expected after (?(
664    29  (?R or (?digits must be followed by )    29  (?R or (?[+-]digits must be followed by )
665    30  unknown POSIX class name    30  unknown POSIX class name
666    31  POSIX collating elements are not supported    31  POSIX collating elements are not supported
667    32  this version of PCRE is not compiled with PCRE_UTF8 support    32  this version of PCRE is not compiled with PCRE_UTF8 support
668    33  spare error    33  [this code is not in use]
669    34  character value in \ex{...} sequence is too large    34  character value in \ex{...} sequence is too large
670    35  invalid condition (?(0)    35  invalid condition (?(0)
671    36  \eC not allowed in lookbehind assertion    36  \eC not allowed in lookbehind assertion
# Line 588  both compiling functions. Line 674  both compiling functions.
674    39  closing ) for (?C expected    39  closing ) for (?C expected
675    40  recursive call could loop indefinitely    40  recursive call could loop indefinitely
676    41  unrecognized character after (?P    41  unrecognized character after (?P
677    42  syntax error after (?P    42  syntax error in subpattern name (missing terminator)
678    43  two named groups have the same name    43  two named subpatterns have the same name
679    44  invalid UTF-8 string    44  invalid UTF-8 string
680    45  support for \eP, \ep, and \eX has not been compiled    45  support for \eP, \ep, and \eX has not been compiled
681    46  malformed \eP or \ep sequence    46  malformed \eP or \ep sequence
682    47  unknown property name after \eP or \ep    47  unknown property name after \eP or \ep
683      48  subpattern name is too long (maximum 32 characters)
684      49  too many named subpatterns (maximum 10,000)
685      50  [this code is not in use]
686      51  octal value is greater than \e377 (not in UTF-8 mode)
687      52  internal error: overran compiling workspace
688      53  internal error: previously-checked referenced subpattern not found
689      54  DEFINE group contains more than one branch
690      55  repeating a DEFINE group is not allowed
691      56  inconsistent NEWLINE options"
692      57  \eg is not followed by a braced name or an optionally braced
693            non-zero number
694      58  (?+ or (?- or (?(+ or (?(- must be followed by a non-zero number
695  .  .
696  .  .
697  .SH "STUDYING A PATTERN"  .SH "STUDYING A PATTERN"
# Line 631  options are defined, and this argument s Line 729  options are defined, and this argument s
729  .P  .P
730  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
731  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
732  set to NULL. Otherwise it points to a textual error message. You should  set to NULL. Otherwise it is set to point to a textual error message. This is a
733  therefore test the error pointer for NULL after calling \fBpcre_study()\fP, to  static string that is part of the library. You must not try to free it. You
734  be sure that it has run successfully.  should test the error pointer for NULL after calling \fBpcre_study()\fP, to be
735    sure that it has run successfully.
736  .P  .P
737  This is a typical call to \fBpcre_study\fP():  This is a typical call to \fBpcre_study\fP():
738  .sp  .sp
# Line 652  bytes is created. Line 751  bytes is created.
751  .SH "LOCALE SUPPORT"  .SH "LOCALE SUPPORT"
752  .rs  .rs
753  .sp  .sp
754  PCRE handles caseless matching, and determines whether characters are letters  PCRE handles caseless matching, and determines whether characters are letters,
755  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
756  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
757  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
758  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
759  support.  support. The use of locales with Unicode is discouraged. If you are handling
760  .P  characters with codes greater than 128, you should either use UTF-8 and
761  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.
762  built. This is used when the final argument of \fBpcre_compile()\fP is NULL,  .P
763  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
764  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.
765  default. As more and more applications change to using Unicode, the need for  Normally, the internal tables recognize only ASCII characters. However, when
766  this locale support is expected to die away.  PCRE is built, it is possible to cause the internal tables to be rebuilt in the
767    default "C" locale of the local system, which may cause them to be different.
768    .P
769    The internal tables can always be overridden by tables supplied by the
770    application that calls PCRE. These may be created in a different locale from
771    the default. As more and more applications change to using Unicode, the need
772    for this locale support is expected to die away.
773  .P  .P
774  External tables are built by calling the \fBpcre_maketables()\fP function,  External tables are built by calling the \fBpcre_maketables()\fP function,
775  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 677  the following code could be used: Line 782  the following code could be used:
782    tables = pcre_maketables();    tables = pcre_maketables();
783    re = pcre_compile(..., tables);    re = pcre_compile(..., tables);
784  .sp  .sp
785    The locale name "fr_FR" is used on Linux and other Unix-like systems; if you
786    are using Windows, the name for the French locale is "french".
787    .P
788  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
789  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
790  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 723  check against passing an arbitrary memor Line 831  check against passing an arbitrary memor
831  \fBpcre_fullinfo()\fP, to obtain the length of the compiled pattern:  \fBpcre_fullinfo()\fP, to obtain the length of the compiled pattern:
832  .sp  .sp
833    int rc;    int rc;
834    unsigned long int length;    size_t length;
835    rc = pcre_fullinfo(    rc = pcre_fullinfo(
836      re,               /* result of pcre_compile() */      re,               /* result of pcre_compile() */
837      pe,               /* result of pcre_study(), or NULL */      pe,               /* result of pcre_study(), or NULL */
# Line 755  a NULL table pointer. Line 863  a NULL table pointer.
863    PCRE_INFO_FIRSTBYTE    PCRE_INFO_FIRSTBYTE
864  .sp  .sp
865  Return information about the first byte of any matched string, for a  Return information about the first byte of any matched string, for a
866  non-anchored pattern. (This option used to be called PCRE_INFO_FIRSTCHAR; the  non-anchored pattern. The fourth argument should point to an \fBint\fP
867  old name is still recognized for backwards compatibility.)  variable. (This option used to be called PCRE_INFO_FIRSTCHAR; the old name is
868    still recognized for backwards compatibility.)
869  .P  .P
870  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
871  (cat|cow|coyote), it is returned in the integer pointed to by \fIwhere\fP.  (cat|cow|coyote), its value is returned. Otherwise, if either
 Otherwise, if either  
872  .sp  .sp
873  (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
874  starts with "^", or  starts with "^", or
# Line 779  table indicating a fixed set of bytes fo Line 887  table indicating a fixed set of bytes fo
887  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
888  fourth argument should point to an \fBunsigned char *\fP variable.  fourth argument should point to an \fBunsigned char *\fP variable.
889  .sp  .sp
890      PCRE_INFO_HASCRORLF
891    .sp
892    Return 1 if the pattern contains any explicit matches for CR or LF characters,
893    otherwise 0. The fourth argument should point to an \fBint\fP variable.
894    .sp
895      PCRE_INFO_JCHANGED
896    .sp
897    Return 1 if the (?J) option setting is used in the pattern, otherwise 0. The
898    fourth argument should point to an \fBint\fP variable. The (?J) internal option
899    setting changes the local PCRE_DUPNAMES option.
900    .sp
901    PCRE_INFO_LASTLITERAL    PCRE_INFO_LASTLITERAL
902  .sp  .sp
903  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 795  is -1. Line 914  is -1.
914  .sp  .sp
915  PCRE supports the use of named as well as numbered capturing parentheses. The  PCRE supports the use of named as well as numbered capturing parentheses. The
916  names are just an additional way of identifying the parentheses, which still  names are just an additional way of identifying the parentheses, which still
917  acquire numbers. A convenience function called \fBpcre_get_named_substring()\fP  acquire numbers. Several convenience functions such as
918  is provided for extracting an individual captured substring by name. It is also  \fBpcre_get_named_substring()\fP are provided for extracting captured
919  possible to extract the data directly, by first converting the name to a number  substrings by name. It is also possible to extract the data directly, by first
920  in order to access the correct pointers in the output vector (described with  converting the name to a number in order to access the correct pointers in the
921  \fBpcre_exec()\fP below). To do the conversion, you need to use the  output vector (described with \fBpcre_exec()\fP below). To do the conversion,
922  name-to-number map, which is described by these three values.  you need to use the name-to-number map, which is described by these three
923    values.
924  .P  .P
925  The map consists of a number of fixed-size entries. PCRE_INFO_NAMECOUNT gives  The map consists of a number of fixed-size entries. PCRE_INFO_NAMECOUNT gives
926  the number of entries, and PCRE_INFO_NAMEENTRYSIZE gives the size of each  the number of entries, and PCRE_INFO_NAMEENTRYSIZE gives the size of each
# Line 809  length of the longest name. PCRE_INFO_NA Line 929  length of the longest name. PCRE_INFO_NA
929  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
930  are the number of the capturing parenthesis, most significant byte first. The  are the number of the capturing parenthesis, most significant byte first. The
931  rest of the entry is the corresponding name, zero terminated. The names are in  rest of the entry is the corresponding name, zero terminated. The names are in
932  alphabetical order. For example, consider the following pattern (assume  alphabetical order. When PCRE_DUPNAMES is set, duplicate names are in order of
933    their parentheses numbers. For example, consider the following pattern (assume
934  PCRE_EXTENDED is set, so white space - including newlines - is ignored):  PCRE_EXTENDED is set, so white space - including newlines - is ignored):
935  .sp  .sp
936  .\" JOIN  .\" JOIN
937    (?P<date> (?P<year>(\ed\ed)?\ed\ed) -    (?<date> (?<year>(\ed\ed)?\ed\ed) -
938    (?P<month>\ed\ed) - (?P<day>\ed\ed) )    (?<month>\ed\ed) - (?<day>\ed\ed) )
939  .sp  .sp
940  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
941  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 826  bytes shows in hexadecimal, and undefine Line 947  bytes shows in hexadecimal, and undefine
947    00 02 y  e  a  r  00 ??    00 02 y  e  a  r  00 ??
948  .sp  .sp
949  When writing code to extract data from named subpatterns using the  When writing code to extract data from named subpatterns using the
950  name-to-number map, remember that the length of each entry is likely to be  name-to-number map, remember that the length of the entries is likely to be
951  different for each compiled pattern.  different for each compiled pattern.
952  .sp  .sp
953      PCRE_INFO_OKPARTIAL
954    .sp
955    Return 1 if the pattern can be used for partial matching, otherwise 0. The
956    fourth argument should point to an \fBint\fP variable. The
957    .\" HREF
958    \fBpcrepartial\fP
959    .\"
960    documentation lists the restrictions that apply to patterns when partial
961    matching is used.
962    .sp
963    PCRE_INFO_OPTIONS    PCRE_INFO_OPTIONS
964  .sp  .sp
965  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
966  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
967  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
968  top-level option settings within the pattern itself.  top-level option settings at the start of the pattern itself. In other words,
969    they are the options that will be in force when matching starts. For example,
970    if the pattern /(?im)abc(?-i)d/ is compiled with the PCRE_EXTENDED option, the
971    result is PCRE_CASELESS, PCRE_MULTILINE, and PCRE_EXTENDED.
972  .P  .P
973  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
974  alternatives begin with one of the following:  alternatives begin with one of the following:
# Line 964  Here is an example of a simple call to \ Line 1098  Here is an example of a simple call to \
1098  If the \fIextra\fP argument is not NULL, it must point to a \fBpcre_extra\fP  If the \fIextra\fP argument is not NULL, it must point to a \fBpcre_extra\fP
1099  data block. The \fBpcre_study()\fP function returns such a block (when it  data block. The \fBpcre_study()\fP function returns such a block (when it
1100  doesn't return NULL), but you can also create one for yourself, and pass  doesn't return NULL), but you can also create one for yourself, and pass
1101  additional information in it. The fields in a \fBpcre_extra\fP block are as  additional information in it. The \fBpcre_extra\fP block contains the following
1102  follows:  fields (not necessarily in this order):
1103  .sp  .sp
1104    unsigned long int \fIflags\fP;    unsigned long int \fIflags\fP;
1105    void *\fIstudy_data\fP;    void *\fIstudy_data\fP;
1106    unsigned long int \fImatch_limit\fP;    unsigned long int \fImatch_limit\fP;
1107      unsigned long int \fImatch_limit_recursion\fP;
1108    void *\fIcallout_data\fP;    void *\fIcallout_data\fP;
1109    const unsigned char *\fItables\fP;    const unsigned char *\fItables\fP;
1110  .sp  .sp
# Line 978  are set. The flag bits are: Line 1113  are set. The flag bits are:
1113  .sp  .sp
1114    PCRE_EXTRA_STUDY_DATA    PCRE_EXTRA_STUDY_DATA
1115    PCRE_EXTRA_MATCH_LIMIT    PCRE_EXTRA_MATCH_LIMIT
1116      PCRE_EXTRA_MATCH_LIMIT_RECURSION
1117    PCRE_EXTRA_CALLOUT_DATA    PCRE_EXTRA_CALLOUT_DATA
1118    PCRE_EXTRA_TABLES    PCRE_EXTRA_TABLES
1119  .sp  .sp
# Line 992  but which have a very large number of po Line 1128  but which have a very large number of po
1128  classic example is the use of nested unlimited repeats.  classic example is the use of nested unlimited repeats.
1129  .P  .P
1130  Internally, PCRE uses a function called \fBmatch()\fP which it calls repeatedly  Internally, PCRE uses a function called \fBmatch()\fP which it calls repeatedly
1131  (sometimes recursively). The limit is imposed on the number of times this  (sometimes recursively). The limit set by \fImatch_limit\fP is imposed on the
1132  function is called during a match, which has the effect of limiting the amount  number of times this function is called during a match, which has the effect of
1133  of recursion and backtracking that can take place. For patterns that are not  limiting the amount of backtracking that can take place. For patterns that are
1134  anchored, the count starts from zero for each position in the subject string.  not anchored, the count restarts from zero for each position in the subject
1135    string.
1136  .P  .P
1137  The default limit for the library can be set when PCRE is built; the default  The default value for the limit can be set when PCRE is built; the default
1138  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
1139  reduce the default by suppling \fBpcre_exec()\fP with a \fBpcre_extra\fP block  override the default by suppling \fBpcre_exec()\fP with a \fBpcre_extra\fP
1140  in which \fImatch_limit\fP is set to a smaller value, and  block in which \fImatch_limit\fP is set, and PCRE_EXTRA_MATCH_LIMIT is set in
1141  PCRE_EXTRA_MATCH_LIMIT is set in the \fIflags\fP field. If the limit is  the \fIflags\fP field. If the limit is exceeded, \fBpcre_exec()\fP returns
1142  exceeded, \fBpcre_exec()\fP returns PCRE_ERROR_MATCHLIMIT.  PCRE_ERROR_MATCHLIMIT.
1143    .P
1144    The \fImatch_limit_recursion\fP field is similar to \fImatch_limit\fP, but
1145    instead of limiting the total number of times that \fBmatch()\fP is called, it
1146    limits the depth of recursion. The recursion depth is a smaller number than the
1147    total number of calls, because not all calls to \fBmatch()\fP are recursive.
1148    This limit is of use only if it is set smaller than \fImatch_limit\fP.
1149    .P
1150    Limiting the recursion depth limits the amount of stack that can be used, or,
1151    when PCRE has been compiled to use memory on the heap instead of the stack, the
1152    amount of heap memory that can be used.
1153    .P
1154    The default value for \fImatch_limit_recursion\fP can be set when PCRE is
1155    built; the default default is the same value as the default for
1156    \fImatch_limit\fP. You can override the default by suppling \fBpcre_exec()\fP
1157    with a \fBpcre_extra\fP block in which \fImatch_limit_recursion\fP is set, and
1158    PCRE_EXTRA_MATCH_LIMIT_RECURSION is set in the \fIflags\fP field. If the limit
1159    is exceeded, \fBpcre_exec()\fP returns PCRE_ERROR_RECURSIONLIMIT.
1160  .P  .P
1161  The \fIpcre_callout\fP field is used in conjunction with the "callout" feature,  The \fIpcre_callout\fP field is used in conjunction with the "callout" feature,
1162  which is described in the  which is described in the
# Line 1025  called. See the Line 1179  called. See the
1179  .\"  .\"
1180  documentation for a discussion of saving compiled patterns for later use.  documentation for a discussion of saving compiled patterns for later use.
1181  .  .
1182    .\" HTML <a name="execoptions"></a>
1183  .SS "Option bits for \fBpcre_exec()\fP"  .SS "Option bits for \fBpcre_exec()\fP"
1184  .rs  .rs
1185  .sp  .sp
1186  The unused bits of the \fIoptions\fP argument for \fBpcre_exec()\fP must be  The unused bits of the \fIoptions\fP argument for \fBpcre_exec()\fP must be
1187  zero. The only bits that may be set are PCRE_ANCHORED, PCRE_NOTBOL,  zero. The only bits that may be set are PCRE_ANCHORED, PCRE_NEWLINE_\fIxxx\fP,
1188  PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_UTF8_CHECK and PCRE_PARTIAL.  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_UTF8_CHECK and PCRE_PARTIAL.
1189  .sp  .sp
1190    PCRE_ANCHORED    PCRE_ANCHORED
1191  .sp  .sp
# Line 1039  matching position. If a pattern was comp Line 1194  matching position. If a pattern was comp
1194  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
1195  matching time.  matching time.
1196  .sp  .sp
1197      PCRE_NEWLINE_CR
1198      PCRE_NEWLINE_LF
1199      PCRE_NEWLINE_CRLF
1200      PCRE_NEWLINE_ANYCRLF
1201      PCRE_NEWLINE_ANY
1202    .sp
1203    These options override the newline definition that was chosen or defaulted when
1204    the pattern was compiled. For details, see the description of
1205    \fBpcre_compile()\fP above. During matching, the newline choice affects the
1206    behaviour of the dot, circumflex, and dollar metacharacters. It may also alter
1207    the way the match position is advanced after a match failure for an unanchored
1208    pattern.
1209    .P
1210    When PCRE_NEWLINE_CRLF, PCRE_NEWLINE_ANYCRLF, or PCRE_NEWLINE_ANY is set, and a
1211    match attempt for an unanchored pattern fails when the current position is at a
1212    CRLF sequence, and the pattern contains no explicit matches for CR or NL
1213    characters, the match position is advanced by two characters instead of one, in
1214    other words, to after the CRLF.
1215    .P
1216    The above rule is a compromise that makes the most common cases work as
1217    expected. For example, if the pattern is .+A (and the PCRE_DOTALL option is not
1218    set), it does not match the string "\er\enA" because, after failing at the
1219    start, it skips both the CR and the LF before retrying. However, the pattern
1220    [\er\en]A does match that string, because it contains an explicit CR or LF
1221    reference, and so advances only by one character after the first failure.
1222    Note than an explicit CR or LF reference occurs for negated character classes
1223    such as [^X] because they can match CR or LF characters.
1224    .P
1225    Notwithstanding the above, anomalous effects may still occur when CRLF is a
1226    valid newline sequence and explicit \er or \en escapes appear in the pattern.
1227    .sp
1228    PCRE_NOTBOL    PCRE_NOTBOL
1229  .sp  .sp
1230  This option specifies that first character of the subject string is not the  This option specifies that first character of the subject string is not the
# Line 1080  code that demonstrates how to do this in Line 1266  code that demonstrates how to do this in
1266  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
1267  string is automatically checked when \fBpcre_exec()\fP is subsequently called.  string is automatically checked when \fBpcre_exec()\fP is subsequently called.
1268  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
1269  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
1270  \fBpcre_exec()\fP returns the error PCRE_ERROR_BADUTF8. If \fIstartoffset\fP  strings in the
1271  contains an invalid value, PCRE_ERROR_BADUTF8_OFFSET is returned.  .\" HTML <a href="pcre.html#utf8strings">
1272    .\" </a>
1273    section on UTF-8 support
1274    .\"
1275    in the main
1276    .\" HREF
1277    \fBpcre\fP
1278    .\"
1279    page. If an invalid UTF-8 sequence of bytes is found, \fBpcre_exec()\fP returns
1280    the error PCRE_ERROR_BADUTF8. If \fIstartoffset\fP contains an invalid value,
1281    PCRE_ERROR_BADUTF8_OFFSET is returned.
1282  .P  .P
1283  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
1284  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 1170  is set to the offset of the first charac Line 1366  is set to the offset of the first charac
1366  first pair, \fIovector[0]\fP and \fIovector[1]\fP, identify the portion of the  first pair, \fIovector[0]\fP and \fIovector[1]\fP, identify the portion of the
1367  subject string matched by the entire pattern. The next pair is used for the  subject string matched by the entire pattern. The next pair is used for the
1368  first capturing subpattern, and so on. The value returned by \fBpcre_exec()\fP  first capturing subpattern, and so on. The value returned by \fBpcre_exec()\fP
1369  is the number of pairs that have been set. If there are no capturing  is one more than the highest numbered pair that has been set. For example, if
1370  subpatterns, the return value from a successful match is 1, indicating that  two substrings have been captured, the returned value is 3. If there are no
1371  just the first pair of offsets has been set.  capturing subpatterns, the return value from a successful match is 1,
1372  .P  indicating that just the first pair of offsets has been set.
 Some convenience functions are provided for extracting the captured substrings  
 as separate strings. These are described in the following section.  
 .P  
 It is possible for an capturing subpattern number \fIn+1\fP to match some  
 part of the subject when subpattern \fIn\fP has not been used at all. For  
 example, if the string "abc" is matched against the pattern (a|(z))(bc)  
 subpatterns 1 and 3 are matched, but 2 is not. When this happens, both offset  
 values corresponding to the unused subpattern are set to -1.  
1373  .P  .P
1374  If a capturing subpattern is matched repeatedly, it is the last portion of the  If a capturing subpattern is matched repeatedly, it is the last portion of the
1375  string that it matched that is returned.  string that it matched that is returned.
# Line 1195  the \fIovector\fP is not big enough to r Line 1383  the \fIovector\fP is not big enough to r
1383  has to get additional memory for use during matching. Thus it is usually  has to get additional memory for use during matching. Thus it is usually
1384  advisable to supply an \fIovector\fP.  advisable to supply an \fIovector\fP.
1385  .P  .P
1386  Note that \fBpcre_info()\fP can be used to find out how many capturing  The \fBpcre_info()\fP function can be used to find out how many capturing
1387  subpatterns there are in a compiled pattern. The smallest size for  subpatterns there are in a compiled pattern. The smallest size for
1388  \fIovector\fP that will allow for \fIn\fP captured substrings, in addition to  \fIovector\fP that will allow for \fIn\fP captured substrings, in addition to
1389  the offsets of the substring matched by the whole pattern, is (\fIn\fP+1)*3.  the offsets of the substring matched by the whole pattern, is (\fIn\fP+1)*3.
1390    .P
1391    It is possible for capturing subpattern number \fIn+1\fP to match some part of
1392    the subject when subpattern \fIn\fP has not been used at all. For example, if
1393    the string "abc" is matched against the pattern (a|(z))(bc) the return from the
1394    function is 4, and subpatterns 1 and 3 are matched, but 2 is not. When this
1395    happens, both values in the offset pairs corresponding to unused subpatterns
1396    are set to -1.
1397    .P
1398    Offset values that correspond to unused subpatterns at the end of the
1399    expression are also set to -1. For example, if the string "abc" is matched
1400    against the pattern (abc)(x(yz)?)? subpatterns 2 and 3 are not matched. The
1401    return from the function is 2, because the highest used capturing subpattern
1402    number is 1. However, you can refer to the offsets for the second and third
1403    capturing subpatterns if you wish (assuming the vector is large enough, of
1404    course).
1405    .P
1406    Some convenience functions are provided for extracting the captured substrings
1407    as separate strings. These are described below.
1408  .  .
1409  .\" HTML <a name="errorlist"></a>  .\" HTML <a name="errorlist"></a>
1410  .SS "Return values from \fBpcre_exec()\fP"  .SS "Error return values from \fBpcre_exec()\fP"
1411  .rs  .rs
1412  .sp  .sp
1413  If \fBpcre_exec()\fP fails, it returns a negative number. The following are  If \fBpcre_exec()\fP fails, it returns a negative number. The following are
# Line 1228  compiled in an environment of one endian Line 1434  compiled in an environment of one endian
1434  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
1435  not present.  not present.
1436  .sp  .sp
1437    PCRE_ERROR_UNKNOWN_NODE   (-5)    PCRE_ERROR_UNKNOWN_OPCODE (-5)
1438  .sp  .sp
1439  While running the pattern match, an unknown item was encountered in the  While running the pattern match, an unknown item was encountered in the
1440  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 1250  below). It is never returned by \fBpcre_ Line 1456  below). It is never returned by \fBpcre_
1456  .sp  .sp
1457    PCRE_ERROR_MATCHLIMIT     (-8)    PCRE_ERROR_MATCHLIMIT     (-8)
1458  .sp  .sp
1459  The recursion and backtracking limit, as specified by the \fImatch_limit\fP  The backtracking limit, as specified by the \fImatch_limit\fP field in a
1460  field in a \fBpcre_extra\fP structure (or defaulted) was reached. See the  \fBpcre_extra\fP structure (or defaulted) was reached. See the description
1461  description above.  above.
1462  .sp  .sp
1463    PCRE_ERROR_CALLOUT        (-9)    PCRE_ERROR_CALLOUT        (-9)
1464  .sp  .sp
# Line 1297  in PCRE or by overwriting of the compile Line 1503  in PCRE or by overwriting of the compile
1503    PCRE_ERROR_BADCOUNT       (-15)    PCRE_ERROR_BADCOUNT       (-15)
1504  .sp  .sp
1505  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.
1506    .sp
1507      PCRE_ERROR_RECURSIONLIMIT (-21)
1508    .sp
1509    The internal recursion limit, as specified by the \fImatch_limit_recursion\fP
1510    field in a \fBpcre_extra\fP structure (or defaulted) was reached. See the
1511    description above.
1512    .sp
1513      PCRE_ERROR_BADNEWLINE     (-23)
1514    .sp
1515    An invalid combination of PCRE_NEWLINE_\fIxxx\fP options was given.
1516    .P
1517    Error numbers -16 to -20 and -22 are not used by \fBpcre_exec()\fP.
1518  .  .
1519  .  .
1520  .SH "EXTRACTING CAPTURED SUBSTRINGS BY NUMBER"  .SH "EXTRACTING CAPTURED SUBSTRINGS BY NUMBER"
# Line 1308  This error is given if the value of the Line 1526  This error is given if the value of the
1526  .ti +5n  .ti +5n
1527  .B int \fIbuffersize\fP);  .B int \fIbuffersize\fP);
1528  .PP  .PP
 .br  
1529  .B int pcre_get_substring(const char *\fIsubject\fP, int *\fIovector\fP,  .B int pcre_get_substring(const char *\fIsubject\fP, int *\fIovector\fP,
1530  .ti +5n  .ti +5n
1531  .B int \fIstringcount\fP, int \fIstringnumber\fP,  .B int \fIstringcount\fP, int \fIstringnumber\fP,
1532  .ti +5n  .ti +5n
1533  .B const char **\fIstringptr\fP);  .B const char **\fIstringptr\fP);
1534  .PP  .PP
 .br  
1535  .B int pcre_get_substring_list(const char *\fIsubject\fP,  .B int pcre_get_substring_list(const char *\fIsubject\fP,
1536  .ti +5n  .ti +5n
1537  .B int *\fIovector\fP, int \fIstringcount\fP, "const char ***\fIlistptr\fP);"  .B int *\fIovector\fP, int \fIstringcount\fP, "const char ***\fIlistptr\fP);"
# Line 1326  Captured substrings can be accessed dire Line 1542  Captured substrings can be accessed dire
1542  \fBpcre_get_substring_list()\fP are provided for extracting captured substrings  \fBpcre_get_substring_list()\fP are provided for extracting captured substrings
1543  as new, separate, zero-terminated strings. These functions identify substrings  as new, separate, zero-terminated strings. These functions identify substrings
1544  by number. The next section describes functions for extracting named  by number. The next section describes functions for extracting named
1545  substrings. A substring that contains a binary zero is correctly extracted and  substrings.
1546  has a further zero added on the end, but the result is not, of course,  .P
1547  a C string.  A substring that contains a binary zero is correctly extracted and has a
1548    further zero added on the end, but the result is not, of course, a C string.
1549    However, you can process such a string by referring to the length that is
1550    returned by \fBpcre_copy_substring()\fP and \fBpcre_get_substring()\fP.
1551    Unfortunately, the interface to \fBpcre_get_substring_list()\fP is not adequate
1552    for handling strings containing binary zeros, because the end of the final
1553    string is not independently indicated.
1554  .P  .P
1555  The first three arguments are the same for all three of these functions:  The first three arguments are the same for all three of these functions:
1556  \fIsubject\fP is the subject string that has just been successfully matched,  \fIsubject\fP is the subject string that has just been successfully matched,
# Line 1348  the string is placed in \fIbuffer\fP, wh Line 1570  the string is placed in \fIbuffer\fP, wh
1570  \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
1571  obtained via \fBpcre_malloc\fP, and its address is returned via  obtained via \fBpcre_malloc\fP, and its address is returned via
1572  \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
1573  including the terminating zero, or one of  including the terminating zero, or one of these error codes:
1574  .sp  .sp
1575    PCRE_ERROR_NOMEMORY       (-6)    PCRE_ERROR_NOMEMORY       (-6)
1576  .sp  .sp
# Line 1364  and builds a list of pointers to them. A Line 1586  and builds a list of pointers to them. A
1586  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
1587  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
1588  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
1589  function is zero if all went well, or  function is zero if all went well, or the error code
1590  .sp  .sp
1591    PCRE_ERROR_NOMEMORY       (-6)    PCRE_ERROR_NOMEMORY       (-6)
1592  .sp  .sp
# Line 1383  a previous call of \fBpcre_get_substring Line 1605  a previous call of \fBpcre_get_substring
1605  \fBpcre_get_substring_list()\fP, respectively. They do nothing more than call  \fBpcre_get_substring_list()\fP, respectively. They do nothing more than call
1606  the function pointed to by \fBpcre_free\fP, which of course could be called  the function pointed to by \fBpcre_free\fP, which of course could be called
1607  directly from a C program. However, PCRE is used in some situations where it is  directly from a C program. However, PCRE is used in some situations where it is
1608  linked via a special interface to another programming language which cannot use  linked via a special interface to another programming language that cannot use
1609  \fBpcre_free\fP directly; it is for these cases that the functions are  \fBpcre_free\fP directly; it is for these cases that the functions are
1610  provided.  provided.
1611  .  .
# Line 1395  provided. Line 1617  provided.
1617  .ti +5n  .ti +5n
1618  .B const char *\fIname\fP);  .B const char *\fIname\fP);
1619  .PP  .PP
 .br  
1620  .B int pcre_copy_named_substring(const pcre *\fIcode\fP,  .B int pcre_copy_named_substring(const pcre *\fIcode\fP,
1621  .ti +5n  .ti +5n
1622  .B const char *\fIsubject\fP, int *\fIovector\fP,  .B const char *\fIsubject\fP, int *\fIovector\fP,
# Line 1404  provided. Line 1625  provided.
1625  .ti +5n  .ti +5n
1626  .B char *\fIbuffer\fP, int \fIbuffersize\fP);  .B char *\fIbuffer\fP, int \fIbuffersize\fP);
1627  .PP  .PP
 .br  
1628  .B int pcre_get_named_substring(const pcre *\fIcode\fP,  .B int pcre_get_named_substring(const pcre *\fIcode\fP,
1629  .ti +5n  .ti +5n
1630  .B const char *\fIsubject\fP, int *\fIovector\fP,  .B const char *\fIsubject\fP, int *\fIovector\fP,
# Line 1416  provided. Line 1636  provided.
1636  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.
1637  For example, for this pattern  For example, for this pattern
1638  .sp  .sp
1639    (a+)b(?P<xxx>\ed+)...    (a+)b(?<xxx>\ed+)...
1640  .sp  .sp
1641  the number of the subpattern called "xxx" is 2. You can find the number from  the number of the subpattern called "xxx" is 2. If the name is known to be
1642  the name by calling \fBpcre_get_stringnumber()\fP. The first argument is the  unique (PCRE_DUPNAMES was not set), you can find the number from the name by
1643  compiled pattern, and the second is the name. The yield of the function is the  calling \fBpcre_get_stringnumber()\fP. The first argument is the compiled
1644    pattern, and the second is the name. The yield of the function is the
1645  subpattern number, or PCRE_ERROR_NOSUBSTRING (-7) if there is no subpattern of  subpattern number, or PCRE_ERROR_NOSUBSTRING (-7) if there is no subpattern of
1646  that name.  that name.
1647  .P  .P
# Line 1428  Given the number, you can extract the su Line 1649  Given the number, you can extract the su
1649  functions described in the previous section. For convenience, there are also  functions described in the previous section. For convenience, there are also
1650  two functions that do the whole job.  two functions that do the whole job.
1651  .P  .P
1652  Most of the arguments of \fIpcre_copy_named_substring()\fP and  Most of the arguments of \fBpcre_copy_named_substring()\fP and
1653  \fIpcre_get_named_substring()\fP are the same as those for the similarly named  \fBpcre_get_named_substring()\fP are the same as those for the similarly named
1654  functions that extract by number. As these are described in the previous  functions that extract by number. As these are described in the previous
1655  section, they are not re-described here. There are just two differences:  section, they are not re-described here. There are just two differences:
1656  .P  .P
# Line 1439  pattern. This is needed in order to gain Line 1660  pattern. This is needed in order to gain
1660  translation table.  translation table.
1661  .P  .P
1662  These functions call \fBpcre_get_stringnumber()\fP, and if it succeeds, they  These functions call \fBpcre_get_stringnumber()\fP, and if it succeeds, they
1663  then call \fIpcre_copy_substring()\fP or \fIpcre_get_substring()\fP, as  then call \fBpcre_copy_substring()\fP or \fBpcre_get_substring()\fP, as
1664  appropriate.  appropriate. \fBNOTE:\fP If PCRE_DUPNAMES is set and there are duplicate names,
1665    the behaviour may not be what you want (see the next section).
1666    .
1667    .
1668    .SH "DUPLICATE SUBPATTERN NAMES"
1669    .rs
1670    .sp
1671    .B int pcre_get_stringtable_entries(const pcre *\fIcode\fP,
1672    .ti +5n
1673    .B const char *\fIname\fP, char **\fIfirst\fP, char **\fIlast\fP);
1674    .PP
1675    When a pattern is compiled with the PCRE_DUPNAMES option, names for subpatterns
1676    are not required to be unique. Normally, patterns with duplicate names are such
1677    that in any one match, only one of the named subpatterns participates. An
1678    example is shown in the
1679    .\" HREF
1680    \fBpcrepattern\fP
1681    .\"
1682    documentation.
1683    .P
1684    When duplicates are present, \fBpcre_copy_named_substring()\fP and
1685    \fBpcre_get_named_substring()\fP return the first substring corresponding to
1686    the given name that is set. If none are set, PCRE_ERROR_NOSUBSTRING (-7) is
1687    returned; no data is returned. The \fBpcre_get_stringnumber()\fP function
1688    returns one of the numbers that are associated with the name, but it is not
1689    defined which it is.
1690    .P
1691    If you want to get full details of all captured substrings for a given name,
1692    you must use the \fBpcre_get_stringtable_entries()\fP function. The first
1693    argument is the compiled pattern, and the second is the name. The third and
1694    fourth are pointers to variables which are updated by the function. After it
1695    has run, they point to the first and last entries in the name-to-number table
1696    for the given name. The function itself returns the length of each entry, or
1697    PCRE_ERROR_NOSUBSTRING (-7) if there are none. The format of the table is
1698    described above in the section entitled \fIInformation about a pattern\fP.
1699    Given all the relevant entries for the name, you can extract each of their
1700    numbers, and hence the captured data, if any.
1701  .  .
1702  .  .
1703  .SH "FINDING ALL POSSIBLE MATCHES"  .SH "FINDING ALL POSSIBLE MATCHES"
# Line 1478  will yield PCRE_ERROR_NOMATCH. Line 1735  will yield PCRE_ERROR_NOMATCH.
1735  .B int *\fIworkspace\fP, int \fIwscount\fP);  .B int *\fIworkspace\fP, int \fIwscount\fP);
1736  .P  .P
1737  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
1738  a compiled pattern, using a "DFA" matching algorithm. This has different  a compiled pattern, using a matching algorithm that scans the subject string
1739  characteristics to the normal algorithm, and is not compatible with Perl. Some  just once, and does not backtrack. This has different characteristics to the
1740  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
1741  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
1742  matching algorithms, see the  matching can be useful. For a discussion of the two matching algorithms, see
1743    the
1744  .\" HREF  .\" HREF
1745  \fBpcrematching\fP  \fBpcrematching\fP
1746  .\"  .\"
# Line 1497  here. Line 1755  here.
1755  The two additional arguments provide workspace for the function. The workspace  The two additional arguments provide workspace for the function. The workspace
1756  vector should contain at least 20 elements. It is used for keeping track of  vector should contain at least 20 elements. It is used for keeping track of
1757  multiple paths through the pattern tree. More workspace will be needed for  multiple paths through the pattern tree. More workspace will be needed for
1758  patterns and subjects where there are a lot of possible matches.  patterns and subjects where there are a lot of potential matches.
1759  .P  .P
1760  Here is an example of a simple call to \fBpcre_exec()\fP:  Here is an example of a simple call to \fBpcre_dfa_exec()\fP:
1761  .sp  .sp
1762    int rc;    int rc;
1763    int ovector[10];    int ovector[10];
1764    int wspace[20];    int wspace[20];
1765    rc = pcre_exec(    rc = pcre_dfa_exec(
1766      re,             /* result of pcre_compile() */      re,             /* result of pcre_compile() */
1767      NULL,           /* we didn't study the pattern */      NULL,           /* we didn't study the pattern */
1768      "some string",  /* the subject string */      "some string",  /* the subject string */
# Line 1520  Here is an example of a simple call to \ Line 1778  Here is an example of a simple call to \
1778  .rs  .rs
1779  .sp  .sp
1780  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
1781  zero. The only bits that may be set are PCRE_ANCHORED, PCRE_NOTBOL,  zero. The only bits that may be set are PCRE_ANCHORED, PCRE_NEWLINE_\fIxxx\fP,
1782  PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_UTF8_CHECK, PCRE_PARTIAL,  PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_UTF8_CHECK, PCRE_PARTIAL,
1783  PCRE_DFA_SHORTEST, and PCRE_DFA_RESTART. All but the last three of these are  PCRE_DFA_SHORTEST, and PCRE_DFA_RESTART. All but the last three of these are
1784  the same as for \fBpcre_exec()\fP, so their description is not repeated here.  the same as for \fBpcre_exec()\fP, so their description is not repeated here.
1785  .sp  .sp
# Line 1538  matching string. Line 1796  matching string.
1796    PCRE_DFA_SHORTEST    PCRE_DFA_SHORTEST
1797  .sp  .sp
1798  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
1799  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
1800  this is necessarily the shortest possible match at the first possible matching  works, this is necessarily the shortest possible match at the first possible
1801  point in the subject string.  matching point in the subject string.
1802  .sp  .sp
1803    PCRE_DFA_RESTART    PCRE_DFA_RESTART
1804  .sp  .sp
# Line 1579  the three matched strings are Line 1837  the three matched strings are
1837  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
1838  the number of matched substrings. The substrings themselves are returned in  the number of matched substrings. The substrings themselves are returned in
1839  \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
1840  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
1841  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,
1842  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
1843  data, even though the meaning of the strings is different.)  returns data, even though the meaning of the strings is different.)
1844  .P  .P
1845  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
1846  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 1609  that it does not support, for instance, Line 1867  that it does not support, for instance,
1867  .sp  .sp
1868    PCRE_ERROR_DFA_UCOND      (-17)    PCRE_ERROR_DFA_UCOND      (-17)
1869  .sp  .sp
1870  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
1871  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
1872    group. These are not supported.
1873  .sp  .sp
1874    PCRE_ERROR_DFA_UMLIMIT    (-18)    PCRE_ERROR_DFA_UMLIMIT    (-18)
1875  .sp  .sp
# Line 1629  When a recursive subpattern is processed Line 1888  When a recursive subpattern is processed
1888  recursively, using private vectors for \fIovector\fP and \fIworkspace\fP. This  recursively, using private vectors for \fIovector\fP and \fIworkspace\fP. This
1889  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
1890  extremely rare, as a vector of size 1000 is used.  extremely rare, as a vector of size 1000 is used.
1891  .P  .
1892  .in 0  .
1893  Last updated: 16 May 2005  .SH "SEE ALSO"
1894  .br  .rs
1895  Copyright (c) 1997-2005 University of Cambridge.  .sp
1896    \fBpcrebuild\fP(3), \fBpcrecallout\fP(3), \fBpcrecpp(3)\fP(3),
1897    \fBpcrematching\fP(3), \fBpcrepartial\fP(3), \fBpcreposix\fP(3),
1898    \fBpcreprecompile\fP(3), \fBpcresample\fP(3), \fBpcrestack\fP(3).
1899    .
1900    .
1901    .SH AUTHOR
1902    .rs
1903    .sp
1904    .nf
1905    Philip Hazel
1906    University Computing Service
1907    Cambridge CB2 3QH, England.
1908    .fi
1909    .
1910    .
1911    .SH REVISION
1912    .rs
1913    .sp
1914    .nf
1915    Last updated: 21 August 2007
1916    Copyright (c) 1997-2007 University of Cambridge.
1917    .fi

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