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, |
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, |
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, |
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, |
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 |
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 |
.\" |
.\" |
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. |
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 |
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. The choice of newline convention does not affect the |
244 |
|
interpretation of the \en or \er escape sequences. |
245 |
|
. |
246 |
|
. |
247 |
.SH MULTITHREADING |
.SH MULTITHREADING |
248 |
.rs |
.rs |
249 |
.sp |
.sp |
265 |
.\" HREF |
.\" HREF |
266 |
\fBpcreprecompile\fP |
\fBpcreprecompile\fP |
267 |
.\" |
.\" |
268 |
documentation. |
documentation. However, compiling a regular expression with one version of PCRE |
269 |
|
for use with a different version is not guaranteed to work and may cause |
270 |
|
crashes. |
271 |
. |
. |
272 |
. |
. |
273 |
.SH "CHECKING BUILD-TIME OPTIONS" |
.SH "CHECKING BUILD-TIME OPTIONS" |
298 |
.sp |
.sp |
299 |
PCRE_CONFIG_NEWLINE |
PCRE_CONFIG_NEWLINE |
300 |
.sp |
.sp |
301 |
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 |
302 |
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 |
303 |
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 |
304 |
|
default should normally be the standard sequence for your operating system. |
305 |
.sp |
.sp |
306 |
PCRE_CONFIG_LINK_SIZE |
PCRE_CONFIG_LINK_SIZE |
307 |
.sp |
.sp |
327 |
internal matching function calls in a \fBpcre_exec()\fP execution. Further |
internal matching function calls in a \fBpcre_exec()\fP execution. Further |
328 |
details are given with \fBpcre_exec()\fP below. |
details are given with \fBpcre_exec()\fP below. |
329 |
.sp |
.sp |
330 |
|
PCRE_CONFIG_MATCH_LIMIT_RECURSION |
331 |
|
.sp |
332 |
|
The output is an integer that gives the default limit for the depth of |
333 |
|
recursion when calling the internal matching function in a \fBpcre_exec()\fP |
334 |
|
execution. Further details are given with \fBpcre_exec()\fP below. |
335 |
|
.sp |
336 |
PCRE_CONFIG_STACKRECURSE |
PCRE_CONFIG_STACKRECURSE |
337 |
.sp |
.sp |
338 |
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 |
371 |
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 |
372 |
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 |
373 |
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 |
374 |
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. |
375 |
.P |
.P |
376 |
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 |
377 |
depend on memory location, the complete \fBpcre\fP data block is not |
depend on memory location, the complete \fBpcre\fP data block is not |
378 |
fully relocatable, because it may contain a copy of the \fItableptr\fP |
fully relocatable, because it may contain a copy of the \fItableptr\fP |
379 |
argument, which is an address (see below). |
argument, which is an address (see below). |
380 |
.P |
.P |
381 |
The \fIoptions\fP argument contains independent bits that affect the |
The \fIoptions\fP argument contains various bit settings that affect the |
382 |
compilation. It should be zero if no options are required. The available |
compilation. It should be zero if no options are required. The available |
383 |
options are described below. Some of them, in particular, those that are |
options are described below. Some of them, in particular, those that are |
384 |
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 |
388 |
.\" |
.\" |
389 |
documentation). For these options, the contents of the \fIoptions\fP argument |
documentation). For these options, the contents of the \fIoptions\fP argument |
390 |
specifies their initial settings at the start of compilation and execution. The |
specifies their initial settings at the start of compilation and execution. The |
391 |
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 |
392 |
time. |
matching as well as at compile time. |
393 |
.P |
.P |
394 |
If \fIerrptr\fP is NULL, \fBpcre_compile()\fP returns NULL immediately. |
If \fIerrptr\fP is NULL, \fBpcre_compile()\fP returns NULL immediately. |
395 |
Otherwise, if compilation of a pattern fails, \fBpcre_compile()\fP returns |
Otherwise, if compilation of a pattern fails, \fBpcre_compile()\fP returns |
396 |
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 |
397 |
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 |
398 |
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 |
399 |
|
where the error was discovered is placed in the variable pointed to by |
400 |
\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. |
401 |
.P |
.P |
402 |
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 |
460 |
.sp |
.sp |
461 |
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 |
462 |
end of the subject string. Without this option, a dollar also matches |
end of the subject string. Without this option, a dollar also matches |
463 |
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 |
464 |
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. |
465 |
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 |
466 |
a pattern. |
pattern. |
467 |
.sp |
.sp |
468 |
PCRE_DOTALL |
PCRE_DOTALL |
469 |
.sp |
.sp |
470 |
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, |
471 |
including newlines. Without it, newlines are excluded. This option is |
including those that indicate newline. Without it, a dot does not match when |
472 |
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 |
473 |
(?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 |
474 |
character, independent of the setting of this option. |
negative class such as [^a] always matches newline characters, independent of |
475 |
|
the setting of this option. |
476 |
|
.sp |
477 |
|
PCRE_DUPNAMES |
478 |
|
.sp |
479 |
|
If this bit is set, names used to identify capturing subpatterns need not be |
480 |
|
unique. This can be helpful for certain types of pattern when it is known that |
481 |
|
only one instance of the named subpattern can ever be matched. There are more |
482 |
|
details of named subpatterns below; see also the |
483 |
|
.\" HREF |
484 |
|
\fBpcrepattern\fP |
485 |
|
.\" |
486 |
|
documentation. |
487 |
.sp |
.sp |
488 |
PCRE_EXTENDED |
PCRE_EXTENDED |
489 |
.sp |
.sp |
490 |
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 |
491 |
ignored except when escaped or inside a character class. Whitespace does not |
ignored except when escaped or inside a character class. Whitespace does not |
492 |
include the VT character (code 11). In addition, characters between an |
include the VT character (code 11). In addition, characters between an |
493 |
unescaped # outside a character class and the next newline character, |
unescaped # outside a character class and the next newline, inclusive, are also |
494 |
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 |
495 |
be changed within a pattern by a (?x) option setting. |
pattern by a (?x) option setting. |
496 |
.P |
.P |
497 |
This option makes it possible to include comments inside complicated patterns. |
This option makes it possible to include comments inside complicated patterns. |
498 |
Note, however, that this applies only to data characters. Whitespace characters |
Note, however, that this applies only to data characters. Whitespace characters |
506 |
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 |
507 |
special meaning causes an error, thus reserving these combinations for future |
special meaning causes an error, thus reserving these combinations for future |
508 |
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 |
509 |
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 |
510 |
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 |
511 |
pattern. |
this option. It can also be set by a (?X) option setting within a pattern. |
512 |
.sp |
.sp |
513 |
PCRE_FIRSTLINE |
PCRE_FIRSTLINE |
514 |
.sp |
.sp |
515 |
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 |
516 |
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 |
517 |
continue over the newline. |
over the newline. |
518 |
.sp |
.sp |
519 |
PCRE_MULTILINE |
PCRE_MULTILINE |
520 |
.sp |
.sp |
526 |
Perl. |
Perl. |
527 |
.P |
.P |
528 |
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 |
529 |
match immediately following or immediately before any newline in the subject |
match immediately following or immediately before internal newlines in the |
530 |
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 |
531 |
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 |
532 |
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 |
533 |
occurrences of ^ or $ in a pattern, setting PCRE_MULTILINE has no effect. |
occurrences of ^ or $ in a pattern, setting PCRE_MULTILINE has no effect. |
534 |
.sp |
.sp |
535 |
|
PCRE_NEWLINE_CR |
536 |
|
PCRE_NEWLINE_LF |
537 |
|
PCRE_NEWLINE_CRLF |
538 |
|
PCRE_NEWLINE_ANYCRLF |
539 |
|
PCRE_NEWLINE_ANY |
540 |
|
.sp |
541 |
|
These options override the default newline definition that was chosen when PCRE |
542 |
|
was built. Setting the first or the second specifies that a newline is |
543 |
|
indicated by a single character (CR or LF, respectively). Setting |
544 |
|
PCRE_NEWLINE_CRLF specifies that a newline is indicated by the two-character |
545 |
|
CRLF sequence. Setting PCRE_NEWLINE_ANYCRLF specifies that any of the three |
546 |
|
preceding sequences should be recognized. Setting PCRE_NEWLINE_ANY specifies |
547 |
|
that any Unicode newline sequence should be recognized. The Unicode newline |
548 |
|
sequences are the three just mentioned, plus the single characters VT (vertical |
549 |
|
tab, U+000B), FF (formfeed, U+000C), NEL (next line, U+0085), LS (line |
550 |
|
separator, U+2028), and PS (paragraph separator, U+2029). The last two are |
551 |
|
recognized only in UTF-8 mode. |
552 |
|
.P |
553 |
|
The newline setting in the options word uses three bits that are treated |
554 |
|
as a number, giving eight possibilities. Currently only six are used (default |
555 |
|
plus the five values above). This means that if you set more than one newline |
556 |
|
option, the combination may or may not be sensible. For example, |
557 |
|
PCRE_NEWLINE_CR with PCRE_NEWLINE_LF is equivalent to PCRE_NEWLINE_CRLF, but |
558 |
|
other combinations may yield unused numbers and cause an error. |
559 |
|
.P |
560 |
|
The only time that a line break is specially recognized when compiling a |
561 |
|
pattern is if PCRE_EXTENDED is set, and an unescaped # outside a character |
562 |
|
class is encountered. This indicates a comment that lasts until after the next |
563 |
|
line break sequence. In other circumstances, line break sequences are treated |
564 |
|
as literal data, except that in PCRE_EXTENDED mode, both CR and LF are treated |
565 |
|
as whitespace characters and are therefore ignored. |
566 |
|
.P |
567 |
|
The newline option that is set at compile time becomes the default that is used |
568 |
|
for \fBpcre_exec()\fP and \fBpcre_dfa_exec()\fP, but it can be overridden. |
569 |
|
.sp |
570 |
PCRE_NO_AUTO_CAPTURE |
PCRE_NO_AUTO_CAPTURE |
571 |
.sp |
.sp |
572 |
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 |
616 |
.sp |
.sp |
617 |
The following table lists the error codes than may be returned by |
The following table lists the error codes than may be returned by |
618 |
\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 |
619 |
both compiling functions. |
both compiling functions. As PCRE has developed, some error codes have fallen |
620 |
|
out of use. To avoid confusion, they have not been re-used. |
621 |
.sp |
.sp |
622 |
0 no error |
0 no error |
623 |
1 \e at end of pattern |
1 \e at end of pattern |
629 |
7 invalid escape sequence in character class |
7 invalid escape sequence in character class |
630 |
8 range out of order in character class |
8 range out of order in character class |
631 |
9 nothing to repeat |
9 nothing to repeat |
632 |
10 operand of unlimited repeat could match the empty string |
10 [this code is not in use] |
633 |
11 internal error: unexpected repeat |
11 internal error: unexpected repeat |
634 |
12 unrecognized character after (? |
12 unrecognized character after (? |
635 |
13 POSIX named classes are supported only within a class |
13 POSIX named classes are supported only within a class |
638 |
16 erroffset passed as NULL |
16 erroffset passed as NULL |
639 |
17 unknown option bit(s) set |
17 unknown option bit(s) set |
640 |
18 missing ) after comment |
18 missing ) after comment |
641 |
19 parentheses nested too deeply |
19 [this code is not in use] |
642 |
20 regular expression too large |
20 regular expression too large |
643 |
21 failed to get memory |
21 failed to get memory |
644 |
22 unmatched parentheses |
22 unmatched parentheses |
645 |
23 internal error: code overflow |
23 internal error: code overflow |
646 |
24 unrecognized character after (?< |
24 unrecognized character after (?< |
647 |
25 lookbehind assertion is not fixed length |
25 lookbehind assertion is not fixed length |
648 |
26 malformed number after (?( |
26 malformed number or name after (?( |
649 |
27 conditional group contains more than two branches |
27 conditional group contains more than two branches |
650 |
28 assertion expected after (?( |
28 assertion expected after (?( |
651 |
29 (?R or (?digits must be followed by ) |
29 (?R or (?digits must be followed by ) |
652 |
30 unknown POSIX class name |
30 unknown POSIX class name |
653 |
31 POSIX collating elements are not supported |
31 POSIX collating elements are not supported |
654 |
32 this version of PCRE is not compiled with PCRE_UTF8 support |
32 this version of PCRE is not compiled with PCRE_UTF8 support |
655 |
33 spare error |
33 [this code is not in use] |
656 |
34 character value in \ex{...} sequence is too large |
34 character value in \ex{...} sequence is too large |
657 |
35 invalid condition (?(0) |
35 invalid condition (?(0) |
658 |
36 \eC not allowed in lookbehind assertion |
36 \eC not allowed in lookbehind assertion |
661 |
39 closing ) for (?C expected |
39 closing ) for (?C expected |
662 |
40 recursive call could loop indefinitely |
40 recursive call could loop indefinitely |
663 |
41 unrecognized character after (?P |
41 unrecognized character after (?P |
664 |
42 syntax error after (?P |
42 syntax error in subpattern name (missing terminator) |
665 |
43 two named groups have the same name |
43 two named subpatterns have the same name |
666 |
44 invalid UTF-8 string |
44 invalid UTF-8 string |
667 |
45 support for \eP, \ep, and \eX has not been compiled |
45 support for \eP, \ep, and \eX has not been compiled |
668 |
46 malformed \eP or \ep sequence |
46 malformed \eP or \ep sequence |
669 |
47 unknown property name after \eP or \ep |
47 unknown property name after \eP or \ep |
670 |
|
48 subpattern name is too long (maximum 32 characters) |
671 |
|
49 too many named subpatterns (maximum 10,000) |
672 |
|
50 repeated subpattern is too long |
673 |
|
51 octal value is greater than \e377 (not in UTF-8 mode) |
674 |
|
52 internal error: overran compiling workspace |
675 |
|
53 internal error: previously-checked referenced subpattern not found |
676 |
|
54 DEFINE group contains more than one branch |
677 |
|
55 repeating a DEFINE group is not allowed |
678 |
|
56 inconsistent NEWLINE options" |
679 |
. |
. |
680 |
. |
. |
681 |
.SH "STUDYING A PATTERN" |
.SH "STUDYING A PATTERN" |
713 |
.P |
.P |
714 |
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 |
715 |
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 |
716 |
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 |
717 |
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 |
718 |
be sure that it has run successfully. |
should test the error pointer for NULL after calling \fBpcre_study()\fP, to be |
719 |
|
sure that it has run successfully. |
720 |
.P |
.P |
721 |
This is a typical call to \fBpcre_study\fP(): |
This is a typical call to \fBpcre_study\fP(): |
722 |
.sp |
.sp |
735 |
.SH "LOCALE SUPPORT" |
.SH "LOCALE SUPPORT" |
736 |
.rs |
.rs |
737 |
.sp |
.sp |
738 |
PCRE handles caseless matching, and determines whether characters are letters |
PCRE handles caseless matching, and determines whether characters are letters, |
739 |
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 |
740 |
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 |
741 |
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 |
742 |
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 |
743 |
support. |
support. The use of locales with Unicode is discouraged. If you are handling |
744 |
.P |
characters with codes greater than 128, you should either use UTF-8 and |
745 |
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. |
746 |
built. This is used when the final argument of \fBpcre_compile()\fP is NULL, |
.P |
747 |
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 |
748 |
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. |
749 |
default. As more and more applications change to using Unicode, the need for |
Normally, the internal tables recognize only ASCII characters. However, when |
750 |
this locale support is expected to die away. |
PCRE is built, it is possible to cause the internal tables to be rebuilt in the |
751 |
|
default "C" locale of the local system, which may cause them to be different. |
752 |
|
.P |
753 |
|
The internal tables can always be overridden by tables supplied by the |
754 |
|
application that calls PCRE. These may be created in a different locale from |
755 |
|
the default. As more and more applications change to using Unicode, the need |
756 |
|
for this locale support is expected to die away. |
757 |
.P |
.P |
758 |
External tables are built by calling the \fBpcre_maketables()\fP function, |
External tables are built by calling the \fBpcre_maketables()\fP function, |
759 |
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 |
766 |
tables = pcre_maketables(); |
tables = pcre_maketables(); |
767 |
re = pcre_compile(..., tables); |
re = pcre_compile(..., tables); |
768 |
.sp |
.sp |
769 |
|
The locale name "fr_FR" is used on Linux and other Unix-like systems; if you |
770 |
|
are using Windows, the name for the French locale is "french". |
771 |
|
.P |
772 |
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 |
773 |
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 |
774 |
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 |
815 |
\fBpcre_fullinfo()\fP, to obtain the length of the compiled pattern: |
\fBpcre_fullinfo()\fP, to obtain the length of the compiled pattern: |
816 |
.sp |
.sp |
817 |
int rc; |
int rc; |
818 |
unsigned long int length; |
size_t length; |
819 |
rc = pcre_fullinfo( |
rc = pcre_fullinfo( |
820 |
re, /* result of pcre_compile() */ |
re, /* result of pcre_compile() */ |
821 |
pe, /* result of pcre_study(), or NULL */ |
pe, /* result of pcre_study(), or NULL */ |
847 |
PCRE_INFO_FIRSTBYTE |
PCRE_INFO_FIRSTBYTE |
848 |
.sp |
.sp |
849 |
Return information about the first byte of any matched string, for a |
Return information about the first byte of any matched string, for a |
850 |
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 |
851 |
old name is still recognized for backwards compatibility.) |
variable. (This option used to be called PCRE_INFO_FIRSTCHAR; the old name is |
852 |
|
still recognized for backwards compatibility.) |
853 |
.P |
.P |
854 |
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 |
855 |
(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 |
|
856 |
.sp |
.sp |
857 |
(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 |
858 |
starts with "^", or |
starts with "^", or |
871 |
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 |
872 |
fourth argument should point to an \fBunsigned char *\fP variable. |
fourth argument should point to an \fBunsigned char *\fP variable. |
873 |
.sp |
.sp |
874 |
|
PCRE_INFO_JCHANGED |
875 |
|
.sp |
876 |
|
Return 1 if the (?J) option setting is used in the pattern, otherwise 0. The |
877 |
|
fourth argument should point to an \fBint\fP variable. The (?J) internal option |
878 |
|
setting changes the local PCRE_DUPNAMES value. |
879 |
|
.sp |
880 |
PCRE_INFO_LASTLITERAL |
PCRE_INFO_LASTLITERAL |
881 |
.sp |
.sp |
882 |
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 |
893 |
.sp |
.sp |
894 |
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 |
895 |
names are just an additional way of identifying the parentheses, which still |
names are just an additional way of identifying the parentheses, which still |
896 |
acquire numbers. A convenience function called \fBpcre_get_named_substring()\fP |
acquire numbers. Several convenience functions such as |
897 |
is provided for extracting an individual captured substring by name. It is also |
\fBpcre_get_named_substring()\fP are provided for extracting captured |
898 |
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 |
899 |
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 |
900 |
\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, |
901 |
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 |
902 |
|
values. |
903 |
.P |
.P |
904 |
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 |
905 |
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 |
908 |
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 |
909 |
are the number of the capturing parenthesis, most significant byte first. The |
are the number of the capturing parenthesis, most significant byte first. The |
910 |
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 |
911 |
alphabetical order. For example, consider the following pattern (assume |
alphabetical order. When PCRE_DUPNAMES is set, duplicate names are in order of |
912 |
|
their parentheses numbers. For example, consider the following pattern (assume |
913 |
PCRE_EXTENDED is set, so white space - including newlines - is ignored): |
PCRE_EXTENDED is set, so white space - including newlines - is ignored): |
914 |
.sp |
.sp |
915 |
.\" JOIN |
.\" JOIN |
916 |
(?P<date> (?P<year>(\ed\ed)?\ed\ed) - |
(?<date> (?<year>(\ed\ed)?\ed\ed) - |
917 |
(?P<month>\ed\ed) - (?P<day>\ed\ed) ) |
(?<month>\ed\ed) - (?<day>\ed\ed) ) |
918 |
.sp |
.sp |
919 |
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 |
920 |
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 |
926 |
00 02 y e a r 00 ?? |
00 02 y e a r 00 ?? |
927 |
.sp |
.sp |
928 |
When writing code to extract data from named subpatterns using the |
When writing code to extract data from named subpatterns using the |
929 |
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 |
930 |
different for each compiled pattern. |
different for each compiled pattern. |
931 |
.sp |
.sp |
932 |
|
PCRE_INFO_OKPARTIAL |
933 |
|
.sp |
934 |
|
Return 1 if the pattern can be used for partial matching, otherwise 0. The |
935 |
|
fourth argument should point to an \fBint\fP variable. The |
936 |
|
.\" HREF |
937 |
|
\fBpcrepartial\fP |
938 |
|
.\" |
939 |
|
documentation lists the restrictions that apply to patterns when partial |
940 |
|
matching is used. |
941 |
|
.sp |
942 |
PCRE_INFO_OPTIONS |
PCRE_INFO_OPTIONS |
943 |
.sp |
.sp |
944 |
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 |
1074 |
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 |
1075 |
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 |
1076 |
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 |
1077 |
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 |
1078 |
follows: |
fields (not necessarily in this order): |
1079 |
.sp |
.sp |
1080 |
unsigned long int \fIflags\fP; |
unsigned long int \fIflags\fP; |
1081 |
void *\fIstudy_data\fP; |
void *\fIstudy_data\fP; |
1082 |
unsigned long int \fImatch_limit\fP; |
unsigned long int \fImatch_limit\fP; |
1083 |
|
unsigned long int \fImatch_limit_recursion\fP; |
1084 |
void *\fIcallout_data\fP; |
void *\fIcallout_data\fP; |
1085 |
const unsigned char *\fItables\fP; |
const unsigned char *\fItables\fP; |
1086 |
.sp |
.sp |
1089 |
.sp |
.sp |
1090 |
PCRE_EXTRA_STUDY_DATA |
PCRE_EXTRA_STUDY_DATA |
1091 |
PCRE_EXTRA_MATCH_LIMIT |
PCRE_EXTRA_MATCH_LIMIT |
1092 |
|
PCRE_EXTRA_MATCH_LIMIT_RECURSION |
1093 |
PCRE_EXTRA_CALLOUT_DATA |
PCRE_EXTRA_CALLOUT_DATA |
1094 |
PCRE_EXTRA_TABLES |
PCRE_EXTRA_TABLES |
1095 |
.sp |
.sp |
1104 |
classic example is the use of nested unlimited repeats. |
classic example is the use of nested unlimited repeats. |
1105 |
.P |
.P |
1106 |
Internally, PCRE uses a function called \fBmatch()\fP which it calls repeatedly |
Internally, PCRE uses a function called \fBmatch()\fP which it calls repeatedly |
1107 |
(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 |
1108 |
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 |
1109 |
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 |
1110 |
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 |
1111 |
|
string. |
1112 |
.P |
.P |
1113 |
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 |
1114 |
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 |
1115 |
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 |
1116 |
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 |
1117 |
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 |
1118 |
exceeded, \fBpcre_exec()\fP returns PCRE_ERROR_MATCHLIMIT. |
PCRE_ERROR_MATCHLIMIT. |
1119 |
|
.P |
1120 |
|
The \fImatch_limit_recursion\fP field is similar to \fImatch_limit\fP, but |
1121 |
|
instead of limiting the total number of times that \fBmatch()\fP is called, it |
1122 |
|
limits the depth of recursion. The recursion depth is a smaller number than the |
1123 |
|
total number of calls, because not all calls to \fBmatch()\fP are recursive. |
1124 |
|
This limit is of use only if it is set smaller than \fImatch_limit\fP. |
1125 |
|
.P |
1126 |
|
Limiting the recursion depth limits the amount of stack that can be used, or, |
1127 |
|
when PCRE has been compiled to use memory on the heap instead of the stack, the |
1128 |
|
amount of heap memory that can be used. |
1129 |
|
.P |
1130 |
|
The default value for \fImatch_limit_recursion\fP can be set when PCRE is |
1131 |
|
built; the default default is the same value as the default for |
1132 |
|
\fImatch_limit\fP. You can override the default by suppling \fBpcre_exec()\fP |
1133 |
|
with a \fBpcre_extra\fP block in which \fImatch_limit_recursion\fP is set, and |
1134 |
|
PCRE_EXTRA_MATCH_LIMIT_RECURSION is set in the \fIflags\fP field. If the limit |
1135 |
|
is exceeded, \fBpcre_exec()\fP returns PCRE_ERROR_RECURSIONLIMIT. |
1136 |
.P |
.P |
1137 |
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, |
1138 |
which is described in the |
which is described in the |
1159 |
.rs |
.rs |
1160 |
.sp |
.sp |
1161 |
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 |
1162 |
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, |
1163 |
PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_UTF8_CHECK and PCRE_PARTIAL. |
PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_UTF8_CHECK and PCRE_PARTIAL. |
1164 |
.sp |
.sp |
1165 |
PCRE_ANCHORED |
PCRE_ANCHORED |
1166 |
.sp |
.sp |
1169 |
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 |
1170 |
matching time. |
matching time. |
1171 |
.sp |
.sp |
1172 |
|
PCRE_NEWLINE_CR |
1173 |
|
PCRE_NEWLINE_LF |
1174 |
|
PCRE_NEWLINE_CRLF |
1175 |
|
PCRE_NEWLINE_ANYCRLF |
1176 |
|
PCRE_NEWLINE_ANY |
1177 |
|
.sp |
1178 |
|
These options override the newline definition that was chosen or defaulted when |
1179 |
|
the pattern was compiled. For details, see the description of |
1180 |
|
\fBpcre_compile()\fP above. During matching, the newline choice affects the |
1181 |
|
behaviour of the dot, circumflex, and dollar metacharacters. It may also alter |
1182 |
|
the way the match position is advanced after a match failure for an unanchored |
1183 |
|
pattern. When PCRE_NEWLINE_CRLF, PCRE_NEWLINE_ANYCRLF, or PCRE_NEWLINE_ANY is |
1184 |
|
set, and a match attempt fails when the current position is at a CRLF sequence, |
1185 |
|
the match position is advanced by two characters instead of one, in other |
1186 |
|
words, to after the CRLF. |
1187 |
|
.sp |
1188 |
PCRE_NOTBOL |
PCRE_NOTBOL |
1189 |
.sp |
.sp |
1190 |
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 |
1316 |
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 |
1317 |
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 |
1318 |
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 |
1319 |
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 |
1320 |
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 |
1321 |
just the first pair of offsets has been set. |
capturing subpatterns, the return value from a successful match is 1, |
1322 |
.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. |
|
1323 |
.P |
.P |
1324 |
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 |
1325 |
string that it matched that is returned. |
string that it matched that is returned. |
1333 |
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 |
1334 |
advisable to supply an \fIovector\fP. |
advisable to supply an \fIovector\fP. |
1335 |
.P |
.P |
1336 |
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 |
1337 |
subpatterns there are in a compiled pattern. The smallest size for |
subpatterns there are in a compiled pattern. The smallest size for |
1338 |
\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 |
1339 |
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. |
1340 |
|
.P |
1341 |
|
It is possible for capturing subpattern number \fIn+1\fP to match some part of |
1342 |
|
the subject when subpattern \fIn\fP has not been used at all. For example, if |
1343 |
|
the string "abc" is matched against the pattern (a|(z))(bc) the return from the |
1344 |
|
function is 4, and subpatterns 1 and 3 are matched, but 2 is not. When this |
1345 |
|
happens, both values in the offset pairs corresponding to unused subpatterns |
1346 |
|
are set to -1. |
1347 |
|
.P |
1348 |
|
Offset values that correspond to unused subpatterns at the end of the |
1349 |
|
expression are also set to -1. For example, if the string "abc" is matched |
1350 |
|
against the pattern (abc)(x(yz)?)? subpatterns 2 and 3 are not matched. The |
1351 |
|
return from the function is 2, because the highest used capturing subpattern |
1352 |
|
number is 1. However, you can refer to the offsets for the second and third |
1353 |
|
capturing subpatterns if you wish (assuming the vector is large enough, of |
1354 |
|
course). |
1355 |
|
.P |
1356 |
|
Some convenience functions are provided for extracting the captured substrings |
1357 |
|
as separate strings. These are described below. |
1358 |
. |
. |
1359 |
.\" HTML <a name="errorlist"></a> |
.\" HTML <a name="errorlist"></a> |
1360 |
.SS "Return values from \fBpcre_exec()\fP" |
.SS "Error return values from \fBpcre_exec()\fP" |
1361 |
.rs |
.rs |
1362 |
.sp |
.sp |
1363 |
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 |
1384 |
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 |
1385 |
not present. |
not present. |
1386 |
.sp |
.sp |
1387 |
PCRE_ERROR_UNKNOWN_NODE (-5) |
PCRE_ERROR_UNKNOWN_OPCODE (-5) |
1388 |
.sp |
.sp |
1389 |
While running the pattern match, an unknown item was encountered in the |
While running the pattern match, an unknown item was encountered in the |
1390 |
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 |
1406 |
.sp |
.sp |
1407 |
PCRE_ERROR_MATCHLIMIT (-8) |
PCRE_ERROR_MATCHLIMIT (-8) |
1408 |
.sp |
.sp |
1409 |
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 |
1410 |
field in a \fBpcre_extra\fP structure (or defaulted) was reached. See the |
\fBpcre_extra\fP structure (or defaulted) was reached. See the description |
1411 |
description above. |
above. |
1412 |
.sp |
.sp |
1413 |
PCRE_ERROR_CALLOUT (-9) |
PCRE_ERROR_CALLOUT (-9) |
1414 |
.sp |
.sp |
1453 |
PCRE_ERROR_BADCOUNT (-15) |
PCRE_ERROR_BADCOUNT (-15) |
1454 |
.sp |
.sp |
1455 |
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. |
1456 |
|
.sp |
1457 |
|
PCRE_ERROR_RECURSIONLIMIT (-21) |
1458 |
|
.sp |
1459 |
|
The internal recursion limit, as specified by the \fImatch_limit_recursion\fP |
1460 |
|
field in a \fBpcre_extra\fP structure (or defaulted) was reached. See the |
1461 |
|
description above. |
1462 |
|
.sp |
1463 |
|
PCRE_ERROR_NULLWSLIMIT (-22) |
1464 |
|
.sp |
1465 |
|
When a group that can match an empty substring is repeated with an unbounded |
1466 |
|
upper limit, the subject position at the start of the group must be remembered, |
1467 |
|
so that a test for an empty string can be made when the end of the group is |
1468 |
|
reached. Some workspace is required for this; if it runs out, this error is |
1469 |
|
given. |
1470 |
|
.sp |
1471 |
|
PCRE_ERROR_BADNEWLINE (-23) |
1472 |
|
.sp |
1473 |
|
An invalid combination of PCRE_NEWLINE_\fIxxx\fP options was given. |
1474 |
|
.P |
1475 |
|
Error numbers -16 to -20 are not used by \fBpcre_exec()\fP. |
1476 |
. |
. |
1477 |
. |
. |
1478 |
.SH "EXTRACTING CAPTURED SUBSTRINGS BY NUMBER" |
.SH "EXTRACTING CAPTURED SUBSTRINGS BY NUMBER" |
1484 |
.ti +5n |
.ti +5n |
1485 |
.B int \fIbuffersize\fP); |
.B int \fIbuffersize\fP); |
1486 |
.PP |
.PP |
|
.br |
|
1487 |
.B int pcre_get_substring(const char *\fIsubject\fP, int *\fIovector\fP, |
.B int pcre_get_substring(const char *\fIsubject\fP, int *\fIovector\fP, |
1488 |
.ti +5n |
.ti +5n |
1489 |
.B int \fIstringcount\fP, int \fIstringnumber\fP, |
.B int \fIstringcount\fP, int \fIstringnumber\fP, |
1490 |
.ti +5n |
.ti +5n |
1491 |
.B const char **\fIstringptr\fP); |
.B const char **\fIstringptr\fP); |
1492 |
.PP |
.PP |
|
.br |
|
1493 |
.B int pcre_get_substring_list(const char *\fIsubject\fP, |
.B int pcre_get_substring_list(const char *\fIsubject\fP, |
1494 |
.ti +5n |
.ti +5n |
1495 |
.B int *\fIovector\fP, int \fIstringcount\fP, "const char ***\fIlistptr\fP);" |
.B int *\fIovector\fP, int \fIstringcount\fP, "const char ***\fIlistptr\fP);" |
1500 |
\fBpcre_get_substring_list()\fP are provided for extracting captured substrings |
\fBpcre_get_substring_list()\fP are provided for extracting captured substrings |
1501 |
as new, separate, zero-terminated strings. These functions identify substrings |
as new, separate, zero-terminated strings. These functions identify substrings |
1502 |
by number. The next section describes functions for extracting named |
by number. The next section describes functions for extracting named |
1503 |
substrings. A substring that contains a binary zero is correctly extracted and |
substrings. |
1504 |
has a further zero added on the end, but the result is not, of course, |
.P |
1505 |
a C string. |
A substring that contains a binary zero is correctly extracted and has a |
1506 |
|
further zero added on the end, but the result is not, of course, a C string. |
1507 |
|
However, you can process such a string by referring to the length that is |
1508 |
|
returned by \fBpcre_copy_substring()\fP and \fBpcre_get_substring()\fP. |
1509 |
|
Unfortunately, the interface to \fBpcre_get_substring_list()\fP is not adequate |
1510 |
|
for handling strings containing binary zeros, because the end of the final |
1511 |
|
string is not independently indicated. |
1512 |
.P |
.P |
1513 |
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: |
1514 |
\fIsubject\fP is the subject string that has just been successfully matched, |
\fIsubject\fP is the subject string that has just been successfully matched, |
1528 |
\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 |
1529 |
obtained via \fBpcre_malloc\fP, and its address is returned via |
obtained via \fBpcre_malloc\fP, and its address is returned via |
1530 |
\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 |
1531 |
including the terminating zero, or one of |
including the terminating zero, or one of these error codes: |
1532 |
.sp |
.sp |
1533 |
PCRE_ERROR_NOMEMORY (-6) |
PCRE_ERROR_NOMEMORY (-6) |
1534 |
.sp |
.sp |
1544 |
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 |
1545 |
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 |
1546 |
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 |
1547 |
function is zero if all went well, or |
function is zero if all went well, or the error code |
1548 |
.sp |
.sp |
1549 |
PCRE_ERROR_NOMEMORY (-6) |
PCRE_ERROR_NOMEMORY (-6) |
1550 |
.sp |
.sp |
1563 |
\fBpcre_get_substring_list()\fP, respectively. They do nothing more than call |
\fBpcre_get_substring_list()\fP, respectively. They do nothing more than call |
1564 |
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 |
1565 |
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 |
1566 |
linked via a special interface to another programming language which cannot use |
linked via a special interface to another programming language that cannot use |
1567 |
\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 |
1568 |
provided. |
provided. |
1569 |
. |
. |
1575 |
.ti +5n |
.ti +5n |
1576 |
.B const char *\fIname\fP); |
.B const char *\fIname\fP); |
1577 |
.PP |
.PP |
|
.br |
|
1578 |
.B int pcre_copy_named_substring(const pcre *\fIcode\fP, |
.B int pcre_copy_named_substring(const pcre *\fIcode\fP, |
1579 |
.ti +5n |
.ti +5n |
1580 |
.B const char *\fIsubject\fP, int *\fIovector\fP, |
.B const char *\fIsubject\fP, int *\fIovector\fP, |
1583 |
.ti +5n |
.ti +5n |
1584 |
.B char *\fIbuffer\fP, int \fIbuffersize\fP); |
.B char *\fIbuffer\fP, int \fIbuffersize\fP); |
1585 |
.PP |
.PP |
|
.br |
|
1586 |
.B int pcre_get_named_substring(const pcre *\fIcode\fP, |
.B int pcre_get_named_substring(const pcre *\fIcode\fP, |
1587 |
.ti +5n |
.ti +5n |
1588 |
.B const char *\fIsubject\fP, int *\fIovector\fP, |
.B const char *\fIsubject\fP, int *\fIovector\fP, |
1594 |
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. |
1595 |
For example, for this pattern |
For example, for this pattern |
1596 |
.sp |
.sp |
1597 |
(a+)b(?P<xxx>\ed+)... |
(a+)b(?<xxx>\ed+)... |
1598 |
.sp |
.sp |
1599 |
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 |
1600 |
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 |
1601 |
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 |
1602 |
|
pattern, and the second is the name. The yield of the function is the |
1603 |
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 |
1604 |
that name. |
that name. |
1605 |
.P |
.P |
1607 |
functions described in the previous section. For convenience, there are also |
functions described in the previous section. For convenience, there are also |
1608 |
two functions that do the whole job. |
two functions that do the whole job. |
1609 |
.P |
.P |
1610 |
Most of the arguments of \fIpcre_copy_named_substring()\fP and |
Most of the arguments of \fBpcre_copy_named_substring()\fP and |
1611 |
\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 |
1612 |
functions that extract by number. As these are described in the previous |
functions that extract by number. As these are described in the previous |
1613 |
section, they are not re-described here. There are just two differences: |
section, they are not re-described here. There are just two differences: |
1614 |
.P |
.P |
1618 |
translation table. |
translation table. |
1619 |
.P |
.P |
1620 |
These functions call \fBpcre_get_stringnumber()\fP, and if it succeeds, they |
These functions call \fBpcre_get_stringnumber()\fP, and if it succeeds, they |
1621 |
then call \fIpcre_copy_substring()\fP or \fIpcre_get_substring()\fP, as |
then call \fBpcre_copy_substring()\fP or \fBpcre_get_substring()\fP, as |
1622 |
appropriate. |
appropriate. \fBNOTE:\fP If PCRE_DUPNAMES is set and there are duplicate names, |
1623 |
|
the behaviour may not be what you want (see the next section). |
1624 |
|
. |
1625 |
|
. |
1626 |
|
.SH "DUPLICATE SUBPATTERN NAMES" |
1627 |
|
.rs |
1628 |
|
.sp |
1629 |
|
.B int pcre_get_stringtable_entries(const pcre *\fIcode\fP, |
1630 |
|
.ti +5n |
1631 |
|
.B const char *\fIname\fP, char **\fIfirst\fP, char **\fIlast\fP); |
1632 |
|
.PP |
1633 |
|
When a pattern is compiled with the PCRE_DUPNAMES option, names for subpatterns |
1634 |
|
are not required to be unique. Normally, patterns with duplicate names are such |
1635 |
|
that in any one match, only one of the named subpatterns participates. An |
1636 |
|
example is shown in the |
1637 |
|
.\" HREF |
1638 |
|
\fBpcrepattern\fP |
1639 |
|
.\" |
1640 |
|
documentation. When duplicates are present, \fBpcre_copy_named_substring()\fP |
1641 |
|
and \fBpcre_get_named_substring()\fP return the first substring corresponding |
1642 |
|
to the given name that is set. If none are set, an empty string is returned. |
1643 |
|
The \fBpcre_get_stringnumber()\fP function returns one of the numbers that are |
1644 |
|
associated with the name, but it is not defined which it is. |
1645 |
|
.sp |
1646 |
|
If you want to get full details of all captured substrings for a given name, |
1647 |
|
you must use the \fBpcre_get_stringtable_entries()\fP function. The first |
1648 |
|
argument is the compiled pattern, and the second is the name. The third and |
1649 |
|
fourth are pointers to variables which are updated by the function. After it |
1650 |
|
has run, they point to the first and last entries in the name-to-number table |
1651 |
|
for the given name. The function itself returns the length of each entry, or |
1652 |
|
PCRE_ERROR_NOSUBSTRING (-7) if there are none. The format of the table is |
1653 |
|
described above in the section entitled \fIInformation about a pattern\fP. |
1654 |
|
Given all the relevant entries for the name, you can extract each of their |
1655 |
|
numbers, and hence the captured data, if any. |
1656 |
. |
. |
1657 |
. |
. |
1658 |
.SH "FINDING ALL POSSIBLE MATCHES" |
.SH "FINDING ALL POSSIBLE MATCHES" |
1690 |
.B int *\fIworkspace\fP, int \fIwscount\fP); |
.B int *\fIworkspace\fP, int \fIwscount\fP); |
1691 |
.P |
.P |
1692 |
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 |
1693 |
a compiled pattern, using a "DFA" matching algorithm. This has different |
a compiled pattern, using a matching algorithm that scans the subject string |
1694 |
characteristics to the normal algorithm, and is not compatible with Perl. Some |
just once, and does not backtrack. This has different characteristics to the |
1695 |
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 |
1696 |
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 |
1697 |
matching algorithms, see the |
matching can be useful. For a discussion of the two matching algorithms, see |
1698 |
|
the |
1699 |
.\" HREF |
.\" HREF |
1700 |
\fBpcrematching\fP |
\fBpcrematching\fP |
1701 |
.\" |
.\" |
1710 |
The two additional arguments provide workspace for the function. The workspace |
The two additional arguments provide workspace for the function. The workspace |
1711 |
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 |
1712 |
multiple paths through the pattern tree. More workspace will be needed for |
multiple paths through the pattern tree. More workspace will be needed for |
1713 |
patterns and subjects where there are a lot of possible matches. |
patterns and subjects where there are a lot of potential matches. |
1714 |
.P |
.P |
1715 |
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: |
1716 |
.sp |
.sp |
1717 |
int rc; |
int rc; |
1718 |
int ovector[10]; |
int ovector[10]; |
1719 |
int wspace[20]; |
int wspace[20]; |
1720 |
rc = pcre_exec( |
rc = pcre_dfa_exec( |
1721 |
re, /* result of pcre_compile() */ |
re, /* result of pcre_compile() */ |
1722 |
NULL, /* we didn't study the pattern */ |
NULL, /* we didn't study the pattern */ |
1723 |
"some string", /* the subject string */ |
"some string", /* the subject string */ |
1733 |
.rs |
.rs |
1734 |
.sp |
.sp |
1735 |
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 |
1736 |
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, |
1737 |
PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_UTF8_CHECK, PCRE_PARTIAL, |
PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_UTF8_CHECK, PCRE_PARTIAL, |
1738 |
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 |
1739 |
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. |
1740 |
.sp |
.sp |
1751 |
PCRE_DFA_SHORTEST |
PCRE_DFA_SHORTEST |
1752 |
.sp |
.sp |
1753 |
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 |
1754 |
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 |
1755 |
this is necessarily the shortest possible match at the first possible matching |
works, this is necessarily the shortest possible match at the first possible |
1756 |
point in the subject string. |
matching point in the subject string. |
1757 |
.sp |
.sp |
1758 |
PCRE_DFA_RESTART |
PCRE_DFA_RESTART |
1759 |
.sp |
.sp |
1792 |
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 |
1793 |
the number of matched substrings. The substrings themselves are returned in |
the number of matched substrings. The substrings themselves are returned in |
1794 |
\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 |
1795 |
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 |
1796 |
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, |
1797 |
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 |
1798 |
data, even though the meaning of the strings is different.) |
returns data, even though the meaning of the strings is different.) |
1799 |
.P |
.P |
1800 |
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 |
1801 |
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 |
1822 |
.sp |
.sp |
1823 |
PCRE_ERROR_DFA_UCOND (-17) |
PCRE_ERROR_DFA_UCOND (-17) |
1824 |
.sp |
.sp |
1825 |
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 |
1826 |
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 |
1827 |
|
group. These are not supported. |
1828 |
.sp |
.sp |
1829 |
PCRE_ERROR_DFA_UMLIMIT (-18) |
PCRE_ERROR_DFA_UMLIMIT (-18) |
1830 |
.sp |
.sp |
1843 |
recursively, using private vectors for \fIovector\fP and \fIworkspace\fP. This |
recursively, using private vectors for \fIovector\fP and \fIworkspace\fP. This |
1844 |
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 |
1845 |
extremely rare, as a vector of size 1000 is used. |
extremely rare, as a vector of size 1000 is used. |
1846 |
.P |
. |
1847 |
.in 0 |
. |
1848 |
Last updated: 16 May 2005 |
.SH "SEE ALSO" |
1849 |
.br |
.rs |
1850 |
Copyright (c) 1997-2005 University of Cambridge. |
.sp |
1851 |
|
\fBpcrebuild\fP(3), \fBpcrecallout\fP(3), \fBpcrecpp(3)\fP(3), |
1852 |
|
\fBpcrematching\fP(3), \fBpcrepartial\fP(3), \fBpcreposix\fP(3), |
1853 |
|
\fBpcreprecompile\fP(3), \fBpcresample\fP(3), \fBpcrestack\fP(3). |
1854 |
|
. |
1855 |
|
. |
1856 |
|
.SH AUTHOR |
1857 |
|
.rs |
1858 |
|
.sp |
1859 |
|
.nf |
1860 |
|
Philip Hazel |
1861 |
|
University Computing Service |
1862 |
|
Cambridge CB2 3QH, England. |
1863 |
|
.fi |
1864 |
|
. |
1865 |
|
. |
1866 |
|
.SH REVISION |
1867 |
|
.rs |
1868 |
|
.sp |
1869 |
|
.nf |
1870 |
|
Last updated: 04 June 2007 |
1871 |
|
Copyright (c) 1997-2007 University of Cambridge. |
1872 |
|
.fi |