/[pcre]/code/trunk/doc/pcreapi.3
ViewVC logotype

Diff of /code/trunk/doc/pcreapi.3

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 921 by ph10, Sat Feb 18 18:45:55 2012 UTC revision 968 by ph10, Sat May 26 14:22:52 2012 UTC
# Line 1  Line 1 
1  .TH PCREAPI 3  .TH PCREAPI 3 "04 May 2012" "PCRE 8.31"
2  .SH NAME  .SH NAME
3  PCRE - Perl-compatible regular expressions  PCRE - Perl-compatible regular expressions
4  .sp  .sp
# Line 302  PCRE supports five different conventions Line 302  PCRE supports five different conventions
302  strings: a single CR (carriage return) character, a single LF (linefeed)  strings: a single CR (carriage return) character, a single LF (linefeed)
303  character, the two-character sequence CRLF, any of the three preceding, or any  character, the two-character sequence CRLF, any of the three preceding, or any
304  Unicode newline sequence. The Unicode newline sequences are the three just  Unicode newline sequence. The Unicode newline sequences are the three just
305  mentioned, plus the single characters VT (vertical tab, U+000B), FF (formfeed,  mentioned, plus the single characters VT (vertical tab, U+000B), FF (form feed,
306  U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and PS  U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and PS
307  (paragraph separator, U+2029).  (paragraph separator, U+2029).
308  .P  .P
# Line 526  documentation). For those options that c Line 526  documentation). For those options that c
526  the pattern, the contents of the \fIoptions\fP argument specifies their  the pattern, the contents of the \fIoptions\fP argument specifies their
527  settings at the start of compilation and execution. The PCRE_ANCHORED,  settings at the start of compilation and execution. The PCRE_ANCHORED,
528  PCRE_BSR_\fIxxx\fP, PCRE_NEWLINE_\fIxxx\fP, PCRE_NO_UTF8_CHECK, and  PCRE_BSR_\fIxxx\fP, PCRE_NEWLINE_\fIxxx\fP, PCRE_NO_UTF8_CHECK, and
529  PCRE_NO_START_OPT options can be set at the time of matching as well as at  PCRE_NO_START_OPTIMIZE options can be set at the time of matching as well as at
530  compile time.  compile time.
531  .P  .P
532  If \fIerrptr\fP is NULL, \fBpcre_compile()\fP returns NULL immediately.  If \fIerrptr\fP is NULL, \fBpcre_compile()\fP returns NULL immediately.
# Line 642  documentation. Line 642  documentation.
642  .sp  .sp
643    PCRE_EXTENDED    PCRE_EXTENDED
644  .sp  .sp
645  If this bit is set, whitespace data characters in the pattern are totally  If this bit is set, white space data characters in the pattern are totally
646  ignored except when escaped or inside a character class. Whitespace does not  ignored except when escaped or inside a character class. White space does not
647  include the VT character (code 11). In addition, characters between an  include the VT character (code 11). In addition, characters between an
648  unescaped # outside a character class and the next newline, inclusive, are also  unescaped # outside a character class and the next newline, inclusive, are also
649  ignored. This is equivalent to Perl's /x option, and it can be changed within a  ignored. This is equivalent to Perl's /x option, and it can be changed within a
# Line 661  comment is a literal newline sequence in Line 661  comment is a literal newline sequence in
661  happen to represent a newline do not count.  happen to represent a newline do not count.
662  .P  .P
663  This option makes it possible to include comments inside complicated patterns.  This option makes it possible to include comments inside complicated patterns.
664  Note, however, that this applies only to data characters. Whitespace characters  Note, however, that this applies only to data characters. White space characters
665  may never appear within special character sequences in a pattern, for example  may never appear within special character sequences in a pattern, for example
666  within the sequence (?( that introduces a conditional subpattern.  within the sequence (?( that introduces a conditional subpattern.
667  .sp  .sp
# Line 741  CRLF sequence. Setting PCRE_NEWLINE_ANYC Line 741  CRLF sequence. Setting PCRE_NEWLINE_ANYC
741  preceding sequences should be recognized. Setting PCRE_NEWLINE_ANY specifies  preceding sequences should be recognized. Setting PCRE_NEWLINE_ANY specifies
742  that any Unicode newline sequence should be recognized. The Unicode newline  that any Unicode newline sequence should be recognized. The Unicode newline
743  sequences are the three just mentioned, plus the single characters VT (vertical  sequences are the three just mentioned, plus the single characters VT (vertical
744  tab, U+000B), FF (formfeed, U+000C), NEL (next line, U+0085), LS (line  tab, U+000B), FF (form feed, U+000C), NEL (next line, U+0085), LS (line
745  separator, U+2028), and PS (paragraph separator, U+2029). For the 8-bit  separator, U+2028), and PS (paragraph separator, U+2029). For the 8-bit
746  library, the last two are recognized only in UTF-8 mode.  library, the last two are recognized only in UTF-8 mode.
747  .P  .P
# Line 753  PCRE_NEWLINE_CR with PCRE_NEWLINE_LF is Line 753  PCRE_NEWLINE_CR with PCRE_NEWLINE_LF is
753  other combinations may yield unused numbers and cause an error.  other combinations may yield unused numbers and cause an error.
754  .P  .P
755  The only time that a line break in a pattern is specially recognized when  The only time that a line break in a pattern is specially recognized when
756  compiling is when PCRE_EXTENDED is set. CR and LF are whitespace characters,  compiling is when PCRE_EXTENDED is set. CR and LF are white space characters,
757  and so are ignored in this mode. Also, an unescaped # outside a character class  and so are ignored in this mode. Also, an unescaped # outside a character class
758  indicates a comment that lasts until after the next line break sequence. In  indicates a comment that lasts until after the next line break sequence. In
759  other circumstances, line break sequences in patterns are treated as literal  other circumstances, line break sequences in patterns are treated as literal
# Line 926  fallen out of use. To avoid confusion, t Line 926  fallen out of use. To avoid confusion, t
926    72  too many forward references    72  too many forward references
927    73  disallowed Unicode code point (>= 0xd800 && <= 0xdfff)    73  disallowed Unicode code point (>= 0xd800 && <= 0xdfff)
928    74  invalid UTF-16 string (specifically UTF-16)    74  invalid UTF-16 string (specifically UTF-16)
929      75  name is too long in (*MARK), (*PRUNE), (*SKIP), or (*THEN)
930  .sp  .sp
931  The numbers 32 and 10000 in errors 48 and 49 are defaults; different values may  The numbers 32 and 10000 in errors 48 and 49 are defaults; different values may
932  be used if the limits were changed when PCRE was built.  be used if the limits were changed when PCRE was built.
# Line 1235  only if it follows something of variable Line 1236  only if it follows something of variable
1236  /^a\ed+z\ed+/ the returned value is "z", but for /^a\edz\ed/ the returned value  /^a\ed+z\ed+/ the returned value is "z", but for /^a\edz\ed/ the returned value
1237  is -1.  is -1.
1238  .sp  .sp
1239      PCRE_INFO_MAXLOOKBEHIND
1240    .sp
1241    Return the number of characters (NB not bytes) in the longest lookbehind
1242    assertion in the pattern. Note that the simple assertions \eb and \eB require a
1243    one-character lookbehind. This information is useful when doing multi-segment
1244    matching using the partial matching facilities.
1245    .sp
1246    PCRE_INFO_MINLENGTH    PCRE_INFO_MINLENGTH
1247  .sp  .sp
1248  If the pattern was studied and a minimum length for matching subject strings  If the pattern was studied and a minimum length for matching subject strings
# Line 1465  fields (not necessarily in this order): Line 1473  fields (not necessarily in this order):
1473  In the 16-bit version of this structure, the \fImark\fP field has type  In the 16-bit version of this structure, the \fImark\fP field has type
1474  "PCRE_UCHAR16 **".  "PCRE_UCHAR16 **".
1475  .P  .P
1476  The \fIflags\fP field is a bitmap that specifies which of the other fields  The \fIflags\fP field is used to specify which of the other fields are set. The
1477  are set. The flag bits are:  flag bits are:
1478  .sp  .sp
1479    PCRE_EXTRA_STUDY_DATA    PCRE_EXTRA_CALLOUT_DATA
1480    PCRE_EXTRA_EXECUTABLE_JIT    PCRE_EXTRA_EXECUTABLE_JIT
1481      PCRE_EXTRA_MARK
1482    PCRE_EXTRA_MATCH_LIMIT    PCRE_EXTRA_MATCH_LIMIT
1483    PCRE_EXTRA_MATCH_LIMIT_RECURSION    PCRE_EXTRA_MATCH_LIMIT_RECURSION
1484    PCRE_EXTRA_CALLOUT_DATA    PCRE_EXTRA_STUDY_DATA
1485    PCRE_EXTRA_TABLES    PCRE_EXTRA_TABLES
   PCRE_EXTRA_MARK  
1486  .sp  .sp
1487  Other flag bits should be set to zero. The \fIstudy_data\fP field and sometimes  Other flag bits should be set to zero. The \fIstudy_data\fP field and sometimes
1488  the \fIexecutable_jit\fP field are set in the \fBpcre_extra\fP block that is  the \fIexecutable_jit\fP field are set in the \fBpcre_extra\fP block that is
1489  returned by \fBpcre_study()\fP, together with the appropriate flag bits. You  returned by \fBpcre_study()\fP, together with the appropriate flag bits. You
1490  should not set these yourself, but you may add to the block by setting the  should not set these yourself, but you may add to the block by setting other
1491  other fields and their corresponding flag bits.  fields and their corresponding flag bits.
1492  .P  .P
1493  The \fImatch_limit\fP field provides a means of preventing PCRE from using up a  The \fImatch_limit\fP field provides a means of preventing PCRE from using up a
1494  vast amount of resources when running patterns that are not going to match,  vast amount of resources when running patterns that are not going to match,
# Line 1734  returned. Line 1742  returned.
1742  .sp  .sp
1743  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
1744  string is automatically checked when \fBpcre_exec()\fP is subsequently called.  string is automatically checked when \fBpcre_exec()\fP is subsequently called.
1745  The value of \fIstartoffset\fP is also checked to ensure that it points to the  The entire string is checked before any other processing takes place. The value
1746  start of a UTF-8 character. There is a discussion about the validity of UTF-8  of \fIstartoffset\fP is also checked to ensure that it points to the start of a
1747  strings in the  UTF-8 character. There is a discussion about the
1748    .\" HTML <a href="pcreunicode.html#utf8strings">
1749    .\" </a>
1750    validity of UTF-8 strings
1751    .\"
1752    in the
1753  .\" HREF  .\" HREF
1754  \fBpcreunicode\fP  \fBpcreunicode\fP
1755  .\"  .\"
# Line 1884  string that it matched that is returned. Line 1897  string that it matched that is returned.
1897  .P  .P
1898  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
1899  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
1900  returns a value of zero. If neither the actual string matched not any captured  returns a value of zero. If neither the actual string matched nor any captured
1901  substrings are of interest, \fBpcre_exec()\fP may be called with \fIovector\fP  substrings are of interest, \fBpcre_exec()\fP may be called with \fIovector\fP
1902  passed as NULL and \fIovecsize\fP as zero. However, if the pattern contains  passed as NULL and \fIovecsize\fP as zero. However, if the pattern contains
1903  back references and the \fIovector\fP is not big enough to remember the related  back references and the \fIovector\fP is not big enough to remember the related
# Line 2084  time. Line 2097  time.
2097  .sp  .sp
2098    PCRE_ERROR_JIT_STACKLIMIT (-27)    PCRE_ERROR_JIT_STACKLIMIT (-27)
2099  .sp  .sp
2100  This error is returned when a pattern that was successfully studied using the  This error is returned when a pattern that was successfully studied using a
2101  PCRE_STUDY_JIT_COMPILE option is being matched, but the memory available for  JIT compile option is being matched, but the memory available for the
2102  the just-in-time processing stack is not large enough. See the  just-in-time processing stack is not large enough. See the
2103  .\" HREF  .\" HREF
2104  \fBpcrejit\fP  \fBpcrejit\fP
2105  .\"  .\"
2106  documentation for more details.  documentation for more details.
2107  .sp  .sp
2108    PCRE_ERROR_BADMODE (-28)    PCRE_ERROR_BADMODE        (-28)
2109  .sp  .sp
2110  This error is given if a pattern that was compiled by the 8-bit library is  This error is given if a pattern that was compiled by the 8-bit library is
2111  passed to a 16-bit library function, or vice versa.  passed to a 16-bit library function, or vice versa.
2112  .sp  .sp
2113    PCRE_ERROR_BADENDIANNESS (-29)    PCRE_ERROR_BADENDIANNESS  (-29)
2114  .sp  .sp
2115  This error is given if a pattern that was compiled and saved is reloaded on a  This error is given if a pattern that was compiled and saved is reloaded on a
2116  host with different endianness. The utility function  host with different endianness. The utility function
2117  \fBpcre_pattern_to_host_byte_order()\fP can be used to convert such a pattern  \fBpcre_pattern_to_host_byte_order()\fP can be used to convert such a pattern
2118  so that it runs on the new host.  so that it runs on the new host.
2119  .P  .P
2120  Error numbers -16 to -20 and -22 are not used by \fBpcre_exec()\fP.  Error numbers -16 to -20, -22, and -30 are not used by \fBpcre_exec()\fP.
2121  .  .
2122  .  .
2123  .\" HTML <a name="badutf8reasons"></a>  .\" HTML <a name="badutf8reasons"></a>
# Line 2622  When a recursive subpattern is processed Line 2635  When a recursive subpattern is processed
2635  recursively, using private vectors for \fIovector\fP and \fIworkspace\fP. This  recursively, using private vectors for \fIovector\fP and \fIworkspace\fP. This
2636  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
2637  extremely rare, as a vector of size 1000 is used.  extremely rare, as a vector of size 1000 is used.
2638    .sp
2639      PCRE_ERROR_DFA_BADRESTART (-30)
2640    .sp
2641    When \fBpcre_dfa_exec()\fP is called with the \fBPCRE_DFA_RESTART\fP option,
2642    some plausibility checks are made on the contents of the workspace, which
2643    should contain data about the previous partial match. If any of these checks
2644    fail, this error is given.
2645  .  .
2646  .  .
2647  .SH "SEE ALSO"  .SH "SEE ALSO"
# Line 2646  Cambridge CB2 3QH, England. Line 2666  Cambridge CB2 3QH, England.
2666  .rs  .rs
2667  .sp  .sp
2668  .nf  .nf
2669  Last updated: 18 February 2012  Last updated: 04 May 2012
2670  Copyright (c) 1997-2012 University of Cambridge.  Copyright (c) 1997-2012 University of Cambridge.
2671  .fi  .fi

Legend:
Removed from v.921  
changed lines
  Added in v.968

  ViewVC Help
Powered by ViewVC 1.1.5