140 |
.\" HREF |
.\" HREF |
141 |
\fBpcresample\fP |
\fBpcresample\fP |
142 |
.\" |
.\" |
143 |
documentation describes how to run it. |
documentation describes how to compile and run it. |
144 |
.P |
.P |
145 |
A second matching function, \fBpcre_dfa_exec()\fP, which is not |
A second matching function, \fBpcre_dfa_exec()\fP, which is not |
146 |
Perl-compatible, is also provided. This uses a different algorithm for the |
Perl-compatible, is also provided. This uses a different algorithm for the |
218 |
documentation. |
documentation. |
219 |
. |
. |
220 |
. |
. |
221 |
|
.\" HTML <a name="newlines"></a> |
222 |
.SH NEWLINES |
.SH NEWLINES |
223 |
.rs |
.rs |
224 |
.sp |
.sp |
236 |
default can be overridden, either when a pattern is compiled, or when it is |
default can be overridden, either when a pattern is compiled, or when it is |
237 |
matched. |
matched. |
238 |
.P |
.P |
239 |
|
At compile time, the newline convention can be specified by the \fIoptions\fP |
240 |
|
argument of \fBpcre_compile()\fP, or it can be specified by special text at the |
241 |
|
start of the pattern itself; this overrides any other settings. See the |
242 |
|
.\" HREF |
243 |
|
\fBpcrepattern\fP |
244 |
|
.\" |
245 |
|
page for details of the special character sequences. |
246 |
|
.P |
247 |
In the PCRE documentation the word "newline" is used to mean "the character or |
In the PCRE documentation the word "newline" is used to mean "the character or |
248 |
pair of characters that indicate a line break". The choice of newline |
pair of characters that indicate a line break". The choice of newline |
249 |
convention affects the handling of the dot, circumflex, and dollar |
convention affects the handling of the dot, circumflex, and dollar |
250 |
metacharacters, the handling of #-comments in /x mode, and, when CRLF is a |
metacharacters, the handling of #-comments in /x mode, and, when CRLF is a |
251 |
recognized line ending sequence, the match position advancement for a |
recognized line ending sequence, the match position advancement for a |
252 |
non-anchored pattern. The choice of newline convention does not affect the |
non-anchored pattern. There is more detail about this in the |
253 |
interpretation of the \en or \er escape sequences. |
.\" HTML <a href="#execoptions"> |
254 |
|
.\" </a> |
255 |
|
section on \fBpcre_exec()\fP options |
256 |
|
.\" |
257 |
|
below. |
258 |
|
.P |
259 |
|
The choice of newline convention does not affect the interpretation of |
260 |
|
the \en or \er escape sequences, nor does it affect what \eR matches, which is |
261 |
|
controlled in a similar way, but by separate options. |
262 |
. |
. |
263 |
. |
. |
264 |
.SH MULTITHREADING |
.SH MULTITHREADING |
317 |
.sp |
.sp |
318 |
The output is an integer whose value specifies the default character sequence |
The output is an integer whose value specifies the default character sequence |
319 |
that is recognized as meaning "newline". The four values that are supported |
that is recognized as meaning "newline". The four values that are supported |
320 |
are: 10 for LF, 13 for CR, 3338 for CRLF, -2 for ANYCRLF, and -1 for ANY. The |
are: 10 for LF, 13 for CR, 3338 for CRLF, -2 for ANYCRLF, and -1 for ANY. |
321 |
default should normally be the standard sequence for your operating system. |
Though they are derived from ASCII, the same values are returned in EBCDIC |
322 |
|
environments. The default should normally correspond to the standard sequence |
323 |
|
for your operating system. |
324 |
|
.sp |
325 |
|
PCRE_CONFIG_BSR |
326 |
|
.sp |
327 |
|
The output is an integer whose value indicates what character sequences the \eR |
328 |
|
escape sequence matches by default. A value of 0 means that \eR matches any |
329 |
|
Unicode line ending sequence; a value of 1 means that \eR matches only CR, LF, |
330 |
|
or CRLF. The default can be overridden when a pattern is compiled or matched. |
331 |
.sp |
.sp |
332 |
PCRE_CONFIG_LINK_SIZE |
PCRE_CONFIG_LINK_SIZE |
333 |
.sp |
.sp |
349 |
.sp |
.sp |
350 |
PCRE_CONFIG_MATCH_LIMIT |
PCRE_CONFIG_MATCH_LIMIT |
351 |
.sp |
.sp |
352 |
The output is an integer that gives the default limit for the number of |
The output is a long integer that gives the default limit for the number of |
353 |
internal matching function calls in a \fBpcre_exec()\fP execution. Further |
internal matching function calls in a \fBpcre_exec()\fP execution. Further |
354 |
details are given with \fBpcre_exec()\fP below. |
details are given with \fBpcre_exec()\fP below. |
355 |
.sp |
.sp |
356 |
PCRE_CONFIG_MATCH_LIMIT_RECURSION |
PCRE_CONFIG_MATCH_LIMIT_RECURSION |
357 |
.sp |
.sp |
358 |
The output is an integer that gives the default limit for the depth of |
The output is a long integer that gives the default limit for the depth of |
359 |
recursion when calling the internal matching function in a \fBpcre_exec()\fP |
recursion when calling the internal matching function in a \fBpcre_exec()\fP |
360 |
execution. Further details are given with \fBpcre_exec()\fP below. |
execution. Further details are given with \fBpcre_exec()\fP below. |
361 |
.sp |
.sp |
406 |
.P |
.P |
407 |
The \fIoptions\fP argument contains various bit settings that affect the |
The \fIoptions\fP argument contains various bit settings that affect the |
408 |
compilation. It should be zero if no options are required. The available |
compilation. It should be zero if no options are required. The available |
409 |
options are described below. Some of them, in particular, those that are |
options are described below. Some of them (in particular, those that are |
410 |
compatible with Perl, can also be set and unset from within the pattern (see |
compatible with Perl, but also some others) can also be set and unset from |
411 |
the detailed description in the |
within the pattern (see the detailed description in the |
412 |
.\" HREF |
.\" HREF |
413 |
\fBpcrepattern\fP |
\fBpcrepattern\fP |
414 |
.\" |
.\" |
415 |
documentation). For these options, the contents of the \fIoptions\fP argument |
documentation). For those options that can be different in different parts of |
416 |
specifies their initial settings at the start of compilation and execution. The |
the pattern, the contents of the \fIoptions\fP argument specifies their initial |
417 |
PCRE_ANCHORED and PCRE_NEWLINE_\fIxxx\fP options can be set at the time of |
settings at the start of compilation and execution. The PCRE_ANCHORED and |
418 |
matching as well as at compile time. |
PCRE_NEWLINE_\fIxxx\fP options can be set at the time of matching as well as at |
419 |
|
compile time. |
420 |
.P |
.P |
421 |
If \fIerrptr\fP is NULL, \fBpcre_compile()\fP returns NULL immediately. |
If \fIerrptr\fP is NULL, \fBpcre_compile()\fP returns NULL immediately. |
422 |
Otherwise, if compilation of a pattern fails, \fBpcre_compile()\fP returns |
Otherwise, if compilation of a pattern fails, \fBpcre_compile()\fP returns |
471 |
.\" |
.\" |
472 |
documentation. |
documentation. |
473 |
.sp |
.sp |
474 |
|
PCRE_BSR_ANYCRLF |
475 |
|
PCRE_BSR_UNICODE |
476 |
|
.sp |
477 |
|
These options (which are mutually exclusive) control what the \eR escape |
478 |
|
sequence matches. The choice is either to match only CR, LF, or CRLF, or to |
479 |
|
match any Unicode newline sequence. The default is specified when PCRE is |
480 |
|
built. It can be overridden from within the pattern, or by setting an option |
481 |
|
when a compiled pattern is matched. |
482 |
|
.sp |
483 |
PCRE_CASELESS |
PCRE_CASELESS |
484 |
.sp |
.sp |
485 |
If this bit is set, letters in the pattern match both upper and lower case |
If this bit is set, letters in the pattern match both upper and lower case |
552 |
the first newline in the subject string, though the matched text may continue |
the first newline in the subject string, though the matched text may continue |
553 |
over the newline. |
over the newline. |
554 |
.sp |
.sp |
555 |
|
PCRE_JAVASCRIPT_COMPAT |
556 |
|
.sp |
557 |
|
If this option is set, PCRE's behaviour is changed in some ways so that it is |
558 |
|
compatible with JavaScript rather than Perl. The changes are as follows: |
559 |
|
.P |
560 |
|
(1) A lone closing square bracket in a pattern causes a compile-time error, |
561 |
|
because this is illegal in JavaScript (by default it is treated as a data |
562 |
|
character). Thus, the pattern AB]CD becomes illegal when this option is set. |
563 |
|
.P |
564 |
|
(2) At run time, a back reference to an unset subpattern group matches an empty |
565 |
|
string (by default this causes the current matching alternative to fail). A |
566 |
|
pattern such as (\e1)(a) succeeds when this option is set (assuming it can find |
567 |
|
an "a" in the subject), whereas it fails by default, for Perl compatibility. |
568 |
|
.sp |
569 |
PCRE_MULTILINE |
PCRE_MULTILINE |
570 |
.sp |
.sp |
571 |
By default, PCRE treats the subject string as consisting of a single line of |
By default, PCRE treats the subject string as consisting of a single line of |
651 |
PCRE_NO_UTF8_CHECK |
PCRE_NO_UTF8_CHECK |
652 |
.sp |
.sp |
653 |
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 |
654 |
automatically checked. If an invalid UTF-8 sequence of bytes is found, |
automatically checked. There is a discussion about the |
655 |
\fBpcre_compile()\fP returns an error. If you already know that your pattern is |
.\" HTML <a href="pcre.html#utf8strings"> |
656 |
valid, and you want to skip this check for performance reasons, you can set the |
.\" </a> |
657 |
PCRE_NO_UTF8_CHECK option. When it is set, the effect of passing an invalid |
validity of UTF-8 strings |
658 |
UTF-8 string as a pattern is undefined. It may cause your program to crash. |
.\" |
659 |
Note that this option can also be passed to \fBpcre_exec()\fP and |
in the main |
660 |
\fBpcre_dfa_exec()\fP, to suppress the UTF-8 validity checking of subject |
.\" HREF |
661 |
strings. |
\fBpcre\fP |
662 |
|
.\" |
663 |
|
page. If an invalid UTF-8 sequence of bytes is found, \fBpcre_compile()\fP |
664 |
|
returns an error. If you already know that your pattern is valid, and you want |
665 |
|
to skip this check for performance reasons, you can set the PCRE_NO_UTF8_CHECK |
666 |
|
option. When it is set, the effect of passing an invalid UTF-8 string as a |
667 |
|
pattern is undefined. It may cause your program to crash. Note that this option |
668 |
|
can also be passed to \fBpcre_exec()\fP and \fBpcre_dfa_exec()\fP, to suppress |
669 |
|
the UTF-8 validity checking of subject strings. |
670 |
. |
. |
671 |
. |
. |
672 |
.SH "COMPILATION ERROR CODES" |
.SH "COMPILATION ERROR CODES" |
689 |
9 nothing to repeat |
9 nothing to repeat |
690 |
10 [this code is not in use] |
10 [this code is not in use] |
691 |
11 internal error: unexpected repeat |
11 internal error: unexpected repeat |
692 |
12 unrecognized character after (? |
12 unrecognized character after (? or (?- |
693 |
13 POSIX named classes are supported only within a class |
13 POSIX named classes are supported only within a class |
694 |
14 missing ) |
14 missing ) |
695 |
15 reference to non-existent subpattern |
15 reference to non-existent subpattern |
697 |
17 unknown option bit(s) set |
17 unknown option bit(s) set |
698 |
18 missing ) after comment |
18 missing ) after comment |
699 |
19 [this code is not in use] |
19 [this code is not in use] |
700 |
20 regular expression too large |
20 regular expression is too large |
701 |
21 failed to get memory |
21 failed to get memory |
702 |
22 unmatched parentheses |
22 unmatched parentheses |
703 |
23 internal error: code overflow |
23 internal error: code overflow |
726 |
46 malformed \eP or \ep sequence |
46 malformed \eP or \ep sequence |
727 |
47 unknown property name after \eP or \ep |
47 unknown property name after \eP or \ep |
728 |
48 subpattern name is too long (maximum 32 characters) |
48 subpattern name is too long (maximum 32 characters) |
729 |
49 too many named subpatterns (maximum 10,000) |
49 too many named subpatterns (maximum 10000) |
730 |
50 [this code is not in use] |
50 [this code is not in use] |
731 |
51 octal value is greater than \e377 (not in UTF-8 mode) |
51 octal value is greater than \e377 (not in UTF-8 mode) |
732 |
52 internal error: overran compiling workspace |
52 internal error: overran compiling workspace |
733 |
53 internal error: previously-checked referenced subpattern not found |
53 internal error: previously-checked referenced subpattern not found |
734 |
54 DEFINE group contains more than one branch |
54 DEFINE group contains more than one branch |
735 |
55 repeating a DEFINE group is not allowed |
55 repeating a DEFINE group is not allowed |
736 |
56 inconsistent NEWLINE options" |
56 inconsistent NEWLINE options |
737 |
57 \eg is not followed by a braced name or an optionally braced |
57 \eg is not followed by a braced, angle-bracketed, or quoted |
738 |
non-zero number |
name/number or by a plain number |
739 |
58 (?+ or (?- or (?(+ or (?(- must be followed by a non-zero number |
58 a numbered reference must not be zero |
740 |
|
59 (*VERB) with an argument is not supported |
741 |
|
60 (*VERB) not recognized |
742 |
|
61 number is too big |
743 |
|
62 subpattern name expected |
744 |
|
63 digit expected after (?+ |
745 |
|
64 ] is an invalid data character in JavaScript compatibility mode |
746 |
|
.sp |
747 |
|
The numbers 32 and 10000 in errors 48 and 49 are defaults; different values may |
748 |
|
be used if the limits were changed when PCRE was built. |
749 |
. |
. |
750 |
. |
. |
751 |
.SH "STUDYING A PATTERN" |
.SH "STUDYING A PATTERN" |
941 |
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 |
942 |
fourth argument should point to an \fBunsigned char *\fP variable. |
fourth argument should point to an \fBunsigned char *\fP variable. |
943 |
.sp |
.sp |
944 |
|
PCRE_INFO_HASCRORLF |
945 |
|
.sp |
946 |
|
Return 1 if the pattern contains any explicit matches for CR or LF characters, |
947 |
|
otherwise 0. The fourth argument should point to an \fBint\fP variable. An |
948 |
|
explicit match is either a literal CR or LF character, or \er or \en. |
949 |
|
.sp |
950 |
PCRE_INFO_JCHANGED |
PCRE_INFO_JCHANGED |
951 |
.sp |
.sp |
952 |
Return 1 if the (?J) option setting is used in the pattern, otherwise 0. The |
Return 1 if the (?J) or (?-J) option setting is used in the pattern, otherwise |
953 |
fourth argument should point to an \fBint\fP variable. The (?J) internal option |
0. The fourth argument should point to an \fBint\fP variable. (?J) and |
954 |
setting changes the local PCRE_DUPNAMES option. |
(?-J) set and unset the local PCRE_DUPNAMES option, respectively. |
955 |
.sp |
.sp |
956 |
PCRE_INFO_LASTLITERAL |
PCRE_INFO_LASTLITERAL |
957 |
.sp |
.sp |
1008 |
PCRE_INFO_OKPARTIAL |
PCRE_INFO_OKPARTIAL |
1009 |
.sp |
.sp |
1010 |
Return 1 if the pattern can be used for partial matching, otherwise 0. The |
Return 1 if the pattern can be used for partial matching, otherwise 0. The |
1011 |
fourth argument should point to an \fBint\fP variable. The |
fourth argument should point to an \fBint\fP variable. From release 8.00, this |
1012 |
|
always returns 1, because the restrictions that previously applied to partial |
1013 |
|
matching have been lifted. The |
1014 |
.\" HREF |
.\" HREF |
1015 |
\fBpcrepartial\fP |
\fBpcrepartial\fP |
1016 |
.\" |
.\" |
1017 |
documentation lists the restrictions that apply to patterns when partial |
documentation gives details of partial matching. |
|
matching is used. |
|
1018 |
.sp |
.sp |
1019 |
PCRE_INFO_OPTIONS |
PCRE_INFO_OPTIONS |
1020 |
.sp |
.sp |
1235 |
.\" |
.\" |
1236 |
documentation for a discussion of saving compiled patterns for later use. |
documentation for a discussion of saving compiled patterns for later use. |
1237 |
. |
. |
1238 |
|
.\" HTML <a name="execoptions"></a> |
1239 |
.SS "Option bits for \fBpcre_exec()\fP" |
.SS "Option bits for \fBpcre_exec()\fP" |
1240 |
.rs |
.rs |
1241 |
.sp |
.sp |
1242 |
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 |
1243 |
zero. The only bits that may be set are PCRE_ANCHORED, PCRE_NEWLINE_\fIxxx\fP, |
zero. The only bits that may be set are PCRE_ANCHORED, PCRE_NEWLINE_\fIxxx\fP, |
1244 |
PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_UTF8_CHECK and PCRE_PARTIAL. |
PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_START_OPTIMIZE, |
1245 |
|
PCRE_NO_UTF8_CHECK and PCRE_PARTIAL. |
1246 |
.sp |
.sp |
1247 |
PCRE_ANCHORED |
PCRE_ANCHORED |
1248 |
.sp |
.sp |
1251 |
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 |
1252 |
matching time. |
matching time. |
1253 |
.sp |
.sp |
1254 |
|
PCRE_BSR_ANYCRLF |
1255 |
|
PCRE_BSR_UNICODE |
1256 |
|
.sp |
1257 |
|
These options (which are mutually exclusive) control what the \eR escape |
1258 |
|
sequence matches. The choice is either to match only CR, LF, or CRLF, or to |
1259 |
|
match any Unicode newline sequence. These options override the choice that was |
1260 |
|
made or defaulted when the pattern was compiled. |
1261 |
|
.sp |
1262 |
PCRE_NEWLINE_CR |
PCRE_NEWLINE_CR |
1263 |
PCRE_NEWLINE_LF |
PCRE_NEWLINE_LF |
1264 |
PCRE_NEWLINE_CRLF |
PCRE_NEWLINE_CRLF |
1270 |
\fBpcre_compile()\fP above. During matching, the newline choice affects the |
\fBpcre_compile()\fP above. During matching, the newline choice affects the |
1271 |
behaviour of the dot, circumflex, and dollar metacharacters. It may also alter |
behaviour of the dot, circumflex, and dollar metacharacters. It may also alter |
1272 |
the way the match position is advanced after a match failure for an unanchored |
the way the match position is advanced after a match failure for an unanchored |
1273 |
pattern. When PCRE_NEWLINE_CRLF, PCRE_NEWLINE_ANYCRLF, or PCRE_NEWLINE_ANY is |
pattern. |
1274 |
set, and a match attempt fails when the current position is at a CRLF sequence, |
.P |
1275 |
the match position is advanced by two characters instead of one, in other |
When PCRE_NEWLINE_CRLF, PCRE_NEWLINE_ANYCRLF, or PCRE_NEWLINE_ANY is set, and a |
1276 |
words, to after the CRLF. |
match attempt for an unanchored pattern fails when the current position is at a |
1277 |
|
CRLF sequence, and the pattern contains no explicit matches for CR or LF |
1278 |
|
characters, the match position is advanced by two characters instead of one, in |
1279 |
|
other words, to after the CRLF. |
1280 |
|
.P |
1281 |
|
The above rule is a compromise that makes the most common cases work as |
1282 |
|
expected. For example, if the pattern is .+A (and the PCRE_DOTALL option is not |
1283 |
|
set), it does not match the string "\er\enA" because, after failing at the |
1284 |
|
start, it skips both the CR and the LF before retrying. However, the pattern |
1285 |
|
[\er\en]A does match that string, because it contains an explicit CR or LF |
1286 |
|
reference, and so advances only by one character after the first failure. |
1287 |
|
.P |
1288 |
|
An explicit match for CR of LF is either a literal appearance of one of those |
1289 |
|
characters, or one of the \er or \en escape sequences. Implicit matches such as |
1290 |
|
[^X] do not count, nor does \es (which includes CR and LF in the characters |
1291 |
|
that it matches). |
1292 |
|
.P |
1293 |
|
Notwithstanding the above, anomalous effects may still occur when CRLF is a |
1294 |
|
valid newline sequence and explicit \er or \en escapes appear in the pattern. |
1295 |
.sp |
.sp |
1296 |
PCRE_NOTBOL |
PCRE_NOTBOL |
1297 |
.sp |
.sp |
1329 |
starting offset (see below) and trying an ordinary match again. There is some |
starting offset (see below) and trying an ordinary match again. There is some |
1330 |
code that demonstrates how to do this in the \fIpcredemo.c\fP sample program. |
code that demonstrates how to do this in the \fIpcredemo.c\fP sample program. |
1331 |
.sp |
.sp |
1332 |
|
PCRE_NO_START_OPTIMIZE |
1333 |
|
.sp |
1334 |
|
There are a number of optimizations that \fBpcre_exec()\fP uses at the start of |
1335 |
|
a match, in order to speed up the process. For example, if it is known that a |
1336 |
|
match must start with a specific character, it searches the subject for that |
1337 |
|
character, and fails immediately if it cannot find it, without actually running |
1338 |
|
the main matching function. When callouts are in use, these optimizations can |
1339 |
|
cause them to be skipped. This option disables the "start-up" optimizations, |
1340 |
|
causing performance to suffer, but ensuring that the callouts do occur. |
1341 |
|
.sp |
1342 |
PCRE_NO_UTF8_CHECK |
PCRE_NO_UTF8_CHECK |
1343 |
.sp |
.sp |
1344 |
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 |
1345 |
string is automatically checked when \fBpcre_exec()\fP is subsequently called. |
string is automatically checked when \fBpcre_exec()\fP is subsequently called. |
1346 |
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 |
1347 |
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 |
1348 |
\fBpcre_exec()\fP returns the error PCRE_ERROR_BADUTF8. If \fIstartoffset\fP |
strings in the |
1349 |
contains an invalid value, PCRE_ERROR_BADUTF8_OFFSET is returned. |
.\" HTML <a href="pcre.html#utf8strings"> |
1350 |
|
.\" </a> |
1351 |
|
section on UTF-8 support |
1352 |
|
.\" |
1353 |
|
in the main |
1354 |
|
.\" HREF |
1355 |
|
\fBpcre\fP |
1356 |
|
.\" |
1357 |
|
page. If an invalid UTF-8 sequence of bytes is found, \fBpcre_exec()\fP returns |
1358 |
|
the error PCRE_ERROR_BADUTF8. If \fIstartoffset\fP contains an invalid value, |
1359 |
|
PCRE_ERROR_BADUTF8_OFFSET is returned. |
1360 |
.P |
.P |
1361 |
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 |
1362 |
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 |
1375 |
the subject was reached (that is, the subject partially matches the pattern and |
the subject was reached (that is, the subject partially matches the pattern and |
1376 |
the failure to match occurred only because there were not enough subject |
the failure to match occurred only because there were not enough subject |
1377 |
characters), \fBpcre_exec()\fP returns PCRE_ERROR_PARTIAL instead of |
characters), \fBpcre_exec()\fP returns PCRE_ERROR_PARTIAL instead of |
1378 |
PCRE_ERROR_NOMATCH. When PCRE_PARTIAL is used, there are restrictions on what |
PCRE_ERROR_NOMATCH. The portion of the string that provided the longest partial |
1379 |
may appear in the pattern. These are discussed in the |
match is set as the first matching string. There is further discussion in the |
1380 |
.\" HREF |
.\" HREF |
1381 |
\fBpcrepartial\fP |
\fBpcrepartial\fP |
1382 |
.\" |
.\" |
1386 |
.rs |
.rs |
1387 |
.sp |
.sp |
1388 |
The subject string is passed to \fBpcre_exec()\fP as a pointer in |
The subject string is passed to \fBpcre_exec()\fP as a pointer in |
1389 |
\fIsubject\fP, a length in \fIlength\fP, and a starting byte offset in |
\fIsubject\fP, a length (in bytes) in \fIlength\fP, and a starting byte offset |
1390 |
\fIstartoffset\fP. In UTF-8 mode, the byte offset must point to the start of a |
in \fIstartoffset\fP. In UTF-8 mode, the byte offset must point to the start of |
1391 |
UTF-8 character. Unlike the pattern string, the subject may contain binary zero |
a UTF-8 character. Unlike the pattern string, the subject may contain binary |
1392 |
bytes. When the starting offset is zero, the search for a match starts at the |
zero bytes. When the starting offset is zero, the search for a match starts at |
1393 |
beginning of the subject, and this is by far the most common case. |
the beginning of the subject, and this is by far the most common case. |
1394 |
.P |
.P |
1395 |
A non-zero starting offset is useful when searching for another match in the |
A non-zero starting offset is useful when searching for another match in the |
1396 |
same subject by calling \fBpcre_exec()\fP again after a previous success. |
same subject by calling \fBpcre_exec()\fP again after a previous success. |
1424 |
a fragment of a pattern that picks out a substring. PCRE supports several other |
a fragment of a pattern that picks out a substring. PCRE supports several other |
1425 |
kinds of parenthesized subpattern that do not cause substrings to be captured. |
kinds of parenthesized subpattern that do not cause substrings to be captured. |
1426 |
.P |
.P |
1427 |
Captured substrings are returned to the caller via a vector of integer offsets |
Captured substrings are returned to the caller via a vector of integers whose |
1428 |
whose address is passed in \fIovector\fP. The number of elements in the vector |
address is passed in \fIovector\fP. The number of elements in the vector is |
1429 |
is passed in \fIovecsize\fP, which must be a non-negative number. \fBNote\fP: |
passed in \fIovecsize\fP, which must be a non-negative number. \fBNote\fP: this |
1430 |
this argument is NOT the size of \fIovector\fP in bytes. |
argument is NOT the size of \fIovector\fP in bytes. |
1431 |
.P |
.P |
1432 |
The first two-thirds of the vector is used to pass back captured substrings, |
The first two-thirds of the vector is used to pass back captured substrings, |
1433 |
each substring using a pair of integers. The remaining third of the vector is |
each substring using a pair of integers. The remaining third of the vector is |
1434 |
used as workspace by \fBpcre_exec()\fP while matching capturing subpatterns, |
used as workspace by \fBpcre_exec()\fP while matching capturing subpatterns, |
1435 |
and is not available for passing back information. The length passed in |
and is not available for passing back information. The number passed in |
1436 |
\fIovecsize\fP should always be a multiple of three. If it is not, it is |
\fIovecsize\fP should always be a multiple of three. If it is not, it is |
1437 |
rounded down. |
rounded down. |
1438 |
.P |
.P |
1439 |
When a match is successful, information about captured substrings is returned |
When a match is successful, information about captured substrings is returned |
1440 |
in pairs of integers, starting at the beginning of \fIovector\fP, and |
in pairs of integers, starting at the beginning of \fIovector\fP, and |
1441 |
continuing up to two-thirds of its length at the most. The first element of a |
continuing up to two-thirds of its length at the most. The first element of |
1442 |
pair is set to the offset of the first character in a substring, and the second |
each pair is set to the byte offset of the first character in a substring, and |
1443 |
is set to the offset of the first character after the end of a substring. The |
the second is set to the byte offset of the first character after the end of a |
1444 |
first pair, \fIovector[0]\fP and \fIovector[1]\fP, identify the portion of the |
substring. \fBNote\fP: these values are always byte offsets, even in UTF-8 |
1445 |
subject string matched by the entire pattern. The next pair is used for the |
mode. They are not character counts. |
1446 |
first capturing subpattern, and so on. The value returned by \fBpcre_exec()\fP |
.P |
1447 |
is one more than the highest numbered pair that has been set. For example, if |
The first pair of integers, \fIovector[0]\fP and \fIovector[1]\fP, identify the |
1448 |
two substrings have been captured, the returned value is 3. If there are no |
portion of the subject string matched by the entire pattern. The next pair is |
1449 |
capturing subpatterns, the return value from a successful match is 1, |
used for the first capturing subpattern, and so on. The value returned by |
1450 |
indicating that just the first pair of offsets has been set. |
\fBpcre_exec()\fP is one more than the highest numbered pair that has been set. |
1451 |
|
For example, if two substrings have been captured, the returned value is 3. If |
1452 |
|
there are no capturing subpatterns, the return value from a successful match is |
1453 |
|
1, indicating that just the first pair of offsets has been set. |
1454 |
.P |
.P |
1455 |
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 |
1456 |
string that it matched that is returned. |
string that it matched that is returned. |
1457 |
.P |
.P |
1458 |
If the vector is too small to hold all the captured substring offsets, it is |
If the vector is too small to hold all the captured substring offsets, it is |
1459 |
used as far as possible (up to two-thirds of its length), and the function |
used as far as possible (up to two-thirds of its length), and the function |
1460 |
returns a value of zero. In particular, if the substring offsets are not of |
returns a value of zero. If the substring offsets are not of interest, |
1461 |
interest, \fBpcre_exec()\fP may be called with \fIovector\fP passed as NULL and |
\fBpcre_exec()\fP may be called with \fIovector\fP passed as NULL and |
1462 |
\fIovecsize\fP as zero. However, if the pattern contains back references and |
\fIovecsize\fP as zero. However, if the pattern contains back references and |
1463 |
the \fIovector\fP is not big enough to remember the related substrings, PCRE |
the \fIovector\fP is not big enough to remember the related substrings, PCRE |
1464 |
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 |
1569 |
.sp |
.sp |
1570 |
PCRE_ERROR_BADPARTIAL (-13) |
PCRE_ERROR_BADPARTIAL (-13) |
1571 |
.sp |
.sp |
1572 |
The PCRE_PARTIAL option was used with a compiled pattern containing items that |
This code is no longer in use. It was formerly returned when the PCRE_PARTIAL |
1573 |
are not supported for partial matching. See the |
option was used with a compiled pattern containing items that were not |
1574 |
.\" HREF |
supported for partial matching. From release 8.00 onwards, there are no |
1575 |
\fBpcrepartial\fP |
restrictions on partial matching. |
|
.\" |
|
|
documentation for details of partial matching. |
|
1576 |
.sp |
.sp |
1577 |
PCRE_ERROR_INTERNAL (-14) |
PCRE_ERROR_INTERNAL (-14) |
1578 |
.sp |
.sp |
1742 |
then call \fBpcre_copy_substring()\fP or \fBpcre_get_substring()\fP, as |
then call \fBpcre_copy_substring()\fP or \fBpcre_get_substring()\fP, as |
1743 |
appropriate. \fBNOTE:\fP If PCRE_DUPNAMES is set and there are duplicate names, |
appropriate. \fBNOTE:\fP If PCRE_DUPNAMES is set and there are duplicate names, |
1744 |
the behaviour may not be what you want (see the next section). |
the behaviour may not be what you want (see the next section). |
1745 |
. |
.P |
1746 |
|
\fBWarning:\fP If the pattern uses the "(?|" feature to set up multiple |
1747 |
|
subpatterns with the same number, you cannot use names to distinguish them, |
1748 |
|
because names are not included in the compiled code. The matching process uses |
1749 |
|
only numbers. |
1750 |
. |
. |
1751 |
.SH "DUPLICATE SUBPATTERN NAMES" |
.SH "DUPLICATE SUBPATTERN NAMES" |
1752 |
.rs |
.rs |
1762 |
.\" HREF |
.\" HREF |
1763 |
\fBpcrepattern\fP |
\fBpcrepattern\fP |
1764 |
.\" |
.\" |
1765 |
documentation. |
documentation. |
1766 |
.P |
.P |
1767 |
When duplicates are present, \fBpcre_copy_named_substring()\fP and |
When duplicates are present, \fBpcre_copy_named_substring()\fP and |
1768 |
\fBpcre_get_named_substring()\fP return the first substring corresponding to |
\fBpcre_get_named_substring()\fP return the first substring corresponding to |
1864 |
zero. The only bits that may be set are PCRE_ANCHORED, PCRE_NEWLINE_\fIxxx\fP, |
zero. The only bits that may be set are PCRE_ANCHORED, PCRE_NEWLINE_\fIxxx\fP, |
1865 |
PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_UTF8_CHECK, PCRE_PARTIAL, |
PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NO_UTF8_CHECK, PCRE_PARTIAL, |
1866 |
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 |
1867 |
the same as for \fBpcre_exec()\fP, so their description is not repeated here. |
exactly the same as for \fBpcre_exec()\fP, so their description is not repeated |
1868 |
|
here. |
1869 |
.sp |
.sp |
1870 |
PCRE_PARTIAL |
PCRE_PARTIAL |
1871 |
.sp |
.sp |
1874 |
\fBpcre_dfa_exec()\fP, the return code PCRE_ERROR_NOMATCH is converted into |
\fBpcre_dfa_exec()\fP, the return code PCRE_ERROR_NOMATCH is converted into |
1875 |
PCRE_ERROR_PARTIAL if the end of the subject is reached, there have been no |
PCRE_ERROR_PARTIAL if the end of the subject is reached, there have been no |
1876 |
complete matches, but there is still at least one matching possibility. The |
complete matches, but there is still at least one matching possibility. The |
1877 |
portion of the string that provided the partial match is set as the first |
portion of the string that provided the longest partial match is set as the |
1878 |
matching string. |
first matching string. |
1879 |
.sp |
.sp |
1880 |
PCRE_DFA_SHORTEST |
PCRE_DFA_SHORTEST |
1881 |
.sp |
.sp |
1996 |
.rs |
.rs |
1997 |
.sp |
.sp |
1998 |
.nf |
.nf |
1999 |
Last updated: 30 July 2007 |
Last updated: 26 August 2009 |
2000 |
Copyright (c) 1997-2007 University of Cambridge. |
Copyright (c) 1997-2009 University of Cambridge. |
2001 |
.fi |
.fi |