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revision 208 by ph10, Mon Aug 6 15:23:29 2007 UTC revision 312 by ph10, Wed Jan 23 18:02:23 2008 UTC
# Line 140  distribution. The Line 140  distribution. The
140  .\" HREF  .\" HREF
141  \fBpcresample\fP  \fBpcresample\fP
142  .\"  .\"
143  documentation describes how to run it.  documentation describes how to compile and run it.
144  .P  .P
145  A second matching function, \fBpcre_dfa_exec()\fP, which is not  A second matching function, \fBpcre_dfa_exec()\fP, which is not
146  Perl-compatible, is also provided. This uses a different algorithm for the  Perl-compatible, is also provided. This uses a different algorithm for the
# Line 218  points during a matching operation. Deta Line 218  points during a matching operation. Deta
218  documentation.  documentation.
219  .  .
220  .  .
221    .\" HTML <a name="newlines"></a>
222  .SH NEWLINES  .SH NEWLINES
223  .rs  .rs
224  .sp  .sp
# Line 235  The default default is LF, which is the Line 236  The default default is LF, which is the
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
# Line 303  that is recognized as meaning "newline". Line 320  that is recognized as meaning "newline".
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. The
321  default should normally be the standard sequence for your operating system.  default should normally be the standard sequence for your operating system.
322  .sp  .sp
323      PCRE_CONFIG_BSR
324    .sp
325    The output is an integer whose value indicates what character sequences the \eR
326    escape sequence matches by default. A value of 0 means that \eR matches any
327    Unicode line ending sequence; a value of 1 means that \eR matches only CR, LF,
328    or CRLF. The default can be overridden when a pattern is compiled or matched.
329    .sp
330    PCRE_CONFIG_LINK_SIZE    PCRE_CONFIG_LINK_SIZE
331  .sp  .sp
332  The output is an integer that contains the number of bytes used for internal  The output is an integer that contains the number of bytes used for internal
# Line 444  facility, see the Line 468  facility, see the
468  .\"  .\"
469  documentation.  documentation.
470  .sp  .sp
471      PCRE_BSR_ANYCRLF
472      PCRE_BSR_UNICODE
473    .sp
474    These options (which are mutually exclusive) control what the \eR escape
475    sequence matches. The choice is either to match only CR, LF, or CRLF, or to
476    match any Unicode newline sequence. The default is specified when PCRE is
477    built. It can be overridden from within the pattern, or by setting an option
478    when a compiled pattern is matched.
479    .sp
480    PCRE_CASELESS    PCRE_CASELESS
481  .sp  .sp
482  If this bit is set, letters in the pattern match both upper and lower case  If this bit is set, letters in the pattern match both upper and lower case
# Line 601  page. Line 634  page.
634    PCRE_NO_UTF8_CHECK    PCRE_NO_UTF8_CHECK
635  .sp  .sp
636  When PCRE_UTF8 is set, the validity of the pattern as a UTF-8 string is  When PCRE_UTF8 is set, the validity of the pattern as a UTF-8 string is
637  automatically checked. If an invalid UTF-8 sequence of bytes is found,  automatically checked. There is a discussion about the
638  \fBpcre_compile()\fP returns an error. If you already know that your pattern is  .\" HTML <a href="pcre.html#utf8strings">
639  valid, and you want to skip this check for performance reasons, you can set the  .\" </a>
640  PCRE_NO_UTF8_CHECK option. When it is set, the effect of passing an invalid  validity of UTF-8 strings
641  UTF-8 string as a pattern is undefined. It may cause your program to crash.  .\"
642  Note that this option can also be passed to \fBpcre_exec()\fP and  in the main
643  \fBpcre_dfa_exec()\fP, to suppress the UTF-8 validity checking of subject  .\" HREF
644  strings.  \fBpcre\fP
645    .\"
646    page. If an invalid UTF-8 sequence of bytes is found, \fBpcre_compile()\fP
647    returns an error. If you already know that your pattern is valid, and you want
648    to skip this check for performance reasons, you can set the PCRE_NO_UTF8_CHECK
649    option. When it is set, the effect of passing an invalid UTF-8 string as a
650    pattern is undefined. It may cause your program to crash. Note that this option
651    can also be passed to \fBpcre_exec()\fP and \fBpcre_dfa_exec()\fP, to suppress
652    the UTF-8 validity checking of subject strings.
653  .  .
654  .  .
655  .SH "COMPILATION ERROR CODES"  .SH "COMPILATION ERROR CODES"
# Line 631  out of use. To avoid confusion, they hav Line 672  out of use. To avoid confusion, they hav
672     9  nothing to repeat     9  nothing to repeat
673    10  [this code is not in use]    10  [this code is not in use]
674    11  internal error: unexpected repeat    11  internal error: unexpected repeat
675    12  unrecognized character after (?    12  unrecognized character after (? or (?-
676    13  POSIX named classes are supported only within a class    13  POSIX named classes are supported only within a class
677    14  missing )    14  missing )
678    15  reference to non-existent subpattern    15  reference to non-existent subpattern
# Line 639  out of use. To avoid confusion, they hav Line 680  out of use. To avoid confusion, they hav
680    17  unknown option bit(s) set    17  unknown option bit(s) set
681    18  missing ) after comment    18  missing ) after comment
682    19  [this code is not in use]    19  [this code is not in use]
683    20  regular expression too large    20  regular expression is too large
684    21  failed to get memory    21  failed to get memory
685    22  unmatched parentheses    22  unmatched parentheses
686    23  internal error: code overflow    23  internal error: code overflow
# Line 668  out of use. To avoid confusion, they hav Line 709  out of use. To avoid confusion, they hav
709    46  malformed \eP or \ep sequence    46  malformed \eP or \ep sequence
710    47  unknown property name after \eP or \ep    47  unknown property name after \eP or \ep
711    48  subpattern name is too long (maximum 32 characters)    48  subpattern name is too long (maximum 32 characters)
712    49  too many named subpatterns (maximum 10,000)    49  too many named subpatterns (maximum 10000)
713    50  [this code is not in use]    50  [this code is not in use]
714    51  octal value is greater than \e377 (not in UTF-8 mode)    51  octal value is greater than \e377 (not in UTF-8 mode)
715    52  internal error: overran compiling workspace    52  internal error: overran compiling workspace
716    53  internal error: previously-checked referenced subpattern not found    53  internal error: previously-checked referenced subpattern not found
717    54  DEFINE group contains more than one branch    54  DEFINE group contains more than one branch
718    55  repeating a DEFINE group is not allowed    55  repeating a DEFINE group is not allowed
719    56  inconsistent NEWLINE options"    56  inconsistent NEWLINE options
720    57  \eg is not followed by a braced name or an optionally braced    57  \eg is not followed by a braced name or an optionally braced
721          non-zero number          non-zero number
722    58  (?+ or (?- or (?(+ or (?(- must be followed by a non-zero number    58  (?+ or (?- or (?(+ or (?(- must be followed by a non-zero number
723      59  (*VERB) with an argument is not supported
724      60  (*VERB) not recognized
725      61  number is too big
726      62  subpattern name expected
727      63  digit expected after (?+
728    .sp
729    The numbers 32 and 10000 in errors 48 and 49 are defaults; different values may
730    be used if the limits were changed when PCRE was built.
731  .  .
732  .  .
733  .SH "STUDYING A PATTERN"  .SH "STUDYING A PATTERN"
# Line 874  table indicating a fixed set of bytes fo Line 923  table indicating a fixed set of bytes fo
923  string, a pointer to the table is returned. Otherwise NULL is returned. The  string, a pointer to the table is returned. Otherwise NULL is returned. The
924  fourth argument should point to an \fBunsigned char *\fP variable.  fourth argument should point to an \fBunsigned char *\fP variable.
925  .sp  .sp
926      PCRE_INFO_HASCRORLF
927    .sp
928    Return 1 if the pattern contains any explicit matches for CR or LF characters,
929    otherwise 0. The fourth argument should point to an \fBint\fP variable. An
930    explicit match is either a literal CR or LF character, or \er or \en.
931    .sp
932    PCRE_INFO_JCHANGED    PCRE_INFO_JCHANGED
933  .sp  .sp
934  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
935  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
936  setting changes the local PCRE_DUPNAMES option.  (?-J) set and unset the local PCRE_DUPNAMES option, respectively.
937  .sp  .sp
938    PCRE_INFO_LASTLITERAL    PCRE_INFO_LASTLITERAL
939  .sp  .sp
# Line 1161  called. See the Line 1216  called. See the
1216  .\"  .\"
1217  documentation for a discussion of saving compiled patterns for later use.  documentation for a discussion of saving compiled patterns for later use.
1218  .  .
1219    .\" HTML <a name="execoptions"></a>
1220  .SS "Option bits for \fBpcre_exec()\fP"  .SS "Option bits for \fBpcre_exec()\fP"
1221  .rs  .rs
1222  .sp  .sp
# Line 1175  matching position. If a pattern was comp Line 1231  matching position. If a pattern was comp
1231  to be anchored by virtue of its contents, it cannot be made unachored at  to be anchored by virtue of its contents, it cannot be made unachored at
1232  matching time.  matching time.
1233  .sp  .sp
1234      PCRE_BSR_ANYCRLF
1235      PCRE_BSR_UNICODE
1236    .sp
1237    These options (which are mutually exclusive) control what the \eR escape
1238    sequence matches. The choice is either to match only CR, LF, or CRLF, or to
1239    match any Unicode newline sequence. These options override the choice that was
1240    made or defaulted when the pattern was compiled.
1241    .sp
1242    PCRE_NEWLINE_CR    PCRE_NEWLINE_CR
1243    PCRE_NEWLINE_LF    PCRE_NEWLINE_LF
1244    PCRE_NEWLINE_CRLF    PCRE_NEWLINE_CRLF
# Line 1186  the pattern was compiled. For details, s Line 1250  the pattern was compiled. For details, s
1250  \fBpcre_compile()\fP above. During matching, the newline choice affects the  \fBpcre_compile()\fP above. During matching, the newline choice affects the
1251  behaviour of the dot, circumflex, and dollar metacharacters. It may also alter  behaviour of the dot, circumflex, and dollar metacharacters. It may also alter
1252  the way the match position is advanced after a match failure for an unanchored  the way the match position is advanced after a match failure for an unanchored
1253  pattern. When PCRE_NEWLINE_CRLF, PCRE_NEWLINE_ANYCRLF, or PCRE_NEWLINE_ANY is  pattern.
1254  set, and a match attempt fails when the current position is at a CRLF sequence,  .P
1255  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
1256  words, to after the CRLF.  match attempt for an unanchored pattern fails when the current position is at a
1257    CRLF sequence, and the pattern contains no explicit matches for CR or LF
1258    characters, the match position is advanced by two characters instead of one, in
1259    other words, to after the CRLF.
1260    .P
1261    The above rule is a compromise that makes the most common cases work as
1262    expected. For example, if the pattern is .+A (and the PCRE_DOTALL option is not
1263    set), it does not match the string "\er\enA" because, after failing at the
1264    start, it skips both the CR and the LF before retrying. However, the pattern
1265    [\er\en]A does match that string, because it contains an explicit CR or LF
1266    reference, and so advances only by one character after the first failure.
1267    .P
1268    An explicit match for CR of LF is either a literal appearance of one of those
1269    characters, or one of the \er or \en escape sequences. Implicit matches such as
1270    [^X] do not count, nor does \es (which includes CR and LF in the characters
1271    that it matches).
1272    .P
1273    Notwithstanding the above, anomalous effects may still occur when CRLF is a
1274    valid newline sequence and explicit \er or \en escapes appear in the pattern.
1275  .sp  .sp
1276    PCRE_NOTBOL    PCRE_NOTBOL
1277  .sp  .sp
# Line 1232  code that demonstrates how to do this in Line 1314  code that demonstrates how to do this in
1314  When PCRE_UTF8 is set at compile time, the validity of the subject as a UTF-8  When PCRE_UTF8 is set at compile time, the validity of the subject as a UTF-8
1315  string is automatically checked when \fBpcre_exec()\fP is subsequently called.  string is automatically checked when \fBpcre_exec()\fP is subsequently called.
1316  The value of \fIstartoffset\fP is also checked to ensure that it points to the  The value of \fIstartoffset\fP is also checked to ensure that it points to the
1317  start of a UTF-8 character. If an invalid UTF-8 sequence of bytes is found,  start of a UTF-8 character. There is a discussion about the validity of UTF-8
1318  \fBpcre_exec()\fP returns the error PCRE_ERROR_BADUTF8. If \fIstartoffset\fP  strings in the
1319  contains an invalid value, PCRE_ERROR_BADUTF8_OFFSET is returned.  .\" HTML <a href="pcre.html#utf8strings">
1320    .\" </a>
1321    section on UTF-8 support
1322    .\"
1323    in the main
1324    .\" HREF
1325    \fBpcre\fP
1326    .\"
1327    page. If an invalid UTF-8 sequence of bytes is found, \fBpcre_exec()\fP returns
1328    the error PCRE_ERROR_BADUTF8. If \fIstartoffset\fP contains an invalid value,
1329    PCRE_ERROR_BADUTF8_OFFSET is returned.
1330  .P  .P
1331  If you already know that your subject is valid, and you want to skip these  If you already know that your subject is valid, and you want to skip these
1332  checks for performance reasons, you can set the PCRE_NO_UTF8_CHECK option when  checks for performance reasons, you can set the PCRE_NO_UTF8_CHECK option when
# Line 1868  Cambridge CB2 3QH, England. Line 1960  Cambridge CB2 3QH, England.
1960  .rs  .rs
1961  .sp  .sp
1962  .nf  .nf
1963  Last updated: 30 July 2007  Last updated: 23 January 2008
1964  Copyright (c) 1997-2007 University of Cambridge.  Copyright (c) 1997-2008 University of Cambridge.
1965  .fi  .fi

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