/[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 950 by ph10, Sat Mar 10 09:23:27 2012 UTC revision 1191 by ph10, Tue Oct 30 16:50:57 2012 UTC
# Line 1  Line 1 
1  .TH PCREAPI 3  .TH PCREAPI 3 "29 October 2012" "PCRE 8.32"
2  .SH NAME  .SH NAME
3  PCRE - Perl-compatible regular expressions  PCRE - Perl-compatible regular expressions
4  .sp  .sp
# Line 134  PCRE - Perl-compatible regular expressio Line 134  PCRE - Perl-compatible regular expressio
134  .B int (*pcre_callout)(pcre_callout_block *);  .B int (*pcre_callout)(pcre_callout_block *);
135  .  .
136  .  .
137  .SH "PCRE 8-BIT AND 16-BIT LIBRARIES"  .SH "PCRE 8-BIT, 16-BIT AND 32-BIT LIBRARIES"
138  .rs  .rs
139  .sp  .sp
140  From release 8.30, PCRE can be compiled as a library for handling 16-bit  From release 8.30, PCRE can be compiled as a library for handling 16-bit
141  character strings as well as, or instead of, the original library that handles  character strings as well as, or instead of, the original library that handles
142  8-bit character strings. To avoid too much complication, this document  8-bit character strings. From release 8.32, PCRE can also be compiled as a
143  describes the 8-bit versions of the functions, with only occasional references  library for handling 32-bit character strings. To avoid too much complication,
144  to the 16-bit library.  this document describes the 8-bit versions of the functions, with only
145  .P  occasional references to the 16-bit and 32-bit libraries.
146  The 16-bit functions operate in the same way as their 8-bit counterparts; they  .P
147  just use different data types for their arguments and results, and their names  The 16-bit and 32-bit functions operate in the same way as their 8-bit
148  start with \fBpcre16_\fP instead of \fBpcre_\fP. For every option that has UTF8  counterparts; they just use different data types for their arguments and
149  in its name (for example, PCRE_UTF8), there is a corresponding 16-bit name with  results, and their names start with \fBpcre16_\fP or \fBpcre32_\fP instead of
150  UTF8 replaced by UTF16. This facility is in fact just cosmetic; the 16-bit  \fBpcre_\fP. For every option that has UTF8 in its name (for example,
151  option names define the same bit values.  PCRE_UTF8), there are corresponding 16-bit and 32-bit names with UTF8 replaced
152    by UTF16 or UTF32, respectively. This facility is in fact just cosmetic; the
153    16-bit and 32-bit option names define the same bit values.
154  .P  .P
155  References to bytes and UTF-8 in this document should be read as references to  References to bytes and UTF-8 in this document should be read as references to
156  16-bit data quantities and UTF-16 when using the 16-bit library, unless  16-bit data quantities and UTF-16 when using the 16-bit library, or 32-bit data
157  specified otherwise. More details of the specific differences for the 16-bit  quantities and UTF-32 when using the 32-bit library, unless specified
158  library are given in the  otherwise. More details of the specific differences for the 16-bit and 32-bit
159    libraries are given in the
160  .\" HREF  .\" HREF
161  \fBpcre16\fP  \fBpcre16\fP
162  .\"  .\"
163  page.  and
164    .\" HREF
165    \fBpcre32\fP
166    .\"
167    pages.
168  .  .
169  .  .
170  .SH "PCRE API OVERVIEW"  .SH "PCRE API OVERVIEW"
# Line 213  used if available, by setting an option Line 220  used if available, by setting an option
220  relevant. More complicated programs might need to make use of the functions  relevant. More complicated programs might need to make use of the functions
221  \fBpcre_jit_stack_alloc()\fP, \fBpcre_jit_stack_free()\fP, and  \fBpcre_jit_stack_alloc()\fP, \fBpcre_jit_stack_free()\fP, and
222  \fBpcre_assign_jit_stack()\fP in order to control the JIT code's memory usage.  \fBpcre_assign_jit_stack()\fP in order to control the JIT code's memory usage.
223  These functions are discussed in the  .P
224    From release 8.32 there is also a direct interface for JIT execution, which
225    gives improved performance. The JIT-specific functions are discussed in the
226  .\" HREF  .\" HREF
227  \fBpcrejit\fP  \fBpcrejit\fP
228  .\"  .\"
# Line 302  PCRE supports five different conventions Line 311  PCRE supports five different conventions
311  strings: a single CR (carriage return) character, a single LF (linefeed)  strings: a single CR (carriage return) character, a single LF (linefeed)
312  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
313  Unicode newline sequence. The Unicode newline sequences are the three just  Unicode newline sequence. The Unicode newline sequences are the three just
314  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,
315  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
316  (paragraph separator, U+2029).  (paragraph separator, U+2029).
317  .P  .P
# Line 392  not recognized. The following informatio Line 401  not recognized. The following informatio
401    PCRE_CONFIG_UTF8    PCRE_CONFIG_UTF8
402  .sp  .sp
403  The output is an integer that is set to one if UTF-8 support is available;  The output is an integer that is set to one if UTF-8 support is available;
404  otherwise it is set to zero. If this option is given to the 16-bit version of  otherwise it is set to zero. This value should normally be given to the 8-bit
405  this function, \fBpcre16_config()\fP, the result is PCRE_ERROR_BADOPTION.  version of this function, \fBpcre_config()\fP. If it is given to the 16-bit
406    or 32-bit version of this function, the result is PCRE_ERROR_BADOPTION.
407  .sp  .sp
408    PCRE_CONFIG_UTF16    PCRE_CONFIG_UTF16
409  .sp  .sp
410  The output is an integer that is set to one if UTF-16 support is available;  The output is an integer that is set to one if UTF-16 support is available;
411  otherwise it is set to zero. This value should normally be given to the 16-bit  otherwise it is set to zero. This value should normally be given to the 16-bit
412  version of this function, \fBpcre16_config()\fP. If it is given to the 8-bit  version of this function, \fBpcre16_config()\fP. If it is given to the 8-bit
413  version of this function, the result is PCRE_ERROR_BADOPTION.  or 32-bit version of this function, the result is PCRE_ERROR_BADOPTION.
414    .sp
415      PCRE_CONFIG_UTF32
416    .sp
417    The output is an integer that is set to one if UTF-32 support is available;
418    otherwise it is set to zero. This value should normally be given to the 32-bit
419    version of this function, \fBpcre32_config()\fP. If it is given to the 8-bit
420    or 16-bit version of this function, the result is PCRE_ERROR_BADOPTION.
421  .sp  .sp
422    PCRE_CONFIG_UNICODE_PROPERTIES    PCRE_CONFIG_UNICODE_PROPERTIES
423  .sp  .sp
# Line 422  unaligned)". If JIT support is not avail Line 439  unaligned)". If JIT support is not avail
439    PCRE_CONFIG_NEWLINE    PCRE_CONFIG_NEWLINE
440  .sp  .sp
441  The output is an integer whose value specifies the default character sequence  The output is an integer whose value specifies the default character sequence
442  that is recognized as meaning "newline". The four values that are supported  that is recognized as meaning "newline". The values that are supported in
443  are: 10 for LF, 13 for CR, 3338 for CRLF, -2 for ANYCRLF, and -1 for ANY.  ASCII/Unicode environments are: 10 for LF, 13 for CR, 3338 for CRLF, -2 for
444  Though they are derived from ASCII, the same values are returned in EBCDIC  ANYCRLF, and -1 for ANY. In EBCDIC environments, CR, ANYCRLF, and ANY yield the
445  environments. The default should normally correspond to the standard sequence  same values. However, the value for LF is normally 21, though some EBCDIC
446  for your operating system.  environments use 37. The corresponding values for CRLF are 3349 and 3365. The
447    default should normally correspond to the standard sequence for your operating
448    system.
449  .sp  .sp
450    PCRE_CONFIG_BSR    PCRE_CONFIG_BSR
451  .sp  .sp
# Line 440  or CRLF. The default can be overridden w Line 459  or CRLF. The default can be overridden w
459  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
460  linkage in compiled regular expressions. For the 8-bit library, the value can  linkage in compiled regular expressions. For the 8-bit library, the value can
461  be 2, 3, or 4. For the 16-bit library, the value is either 2 or 4 and is still  be 2, 3, or 4. For the 16-bit library, the value is either 2 or 4 and is still
462  a number of bytes. The default value of 2 is sufficient for all but the most  a number of bytes. For the 32-bit library, the value is either 2 or 4 and is
463  massive patterns, since it allows the compiled pattern to be up to 64K in size.  still a number of bytes. The default value of 2 is sufficient for all but the
464  Larger values allow larger regular expressions to be compiled, at the expense  most massive patterns, since it allows the compiled pattern to be up to 64K in
465  of slower matching.  size. Larger values allow larger regular expressions to be compiled, at the
466    expense of slower matching.
467  .sp  .sp
468    PCRE_CONFIG_POSIX_MALLOC_THRESHOLD    PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
469  .sp  .sp
# Line 642  documentation. Line 662  documentation.
662  .sp  .sp
663    PCRE_EXTENDED    PCRE_EXTENDED
664  .sp  .sp
665  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
666  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
667  include the VT character (code 11). In addition, characters between an  include the VT character (code 11). In addition, characters between an
668  unescaped # outside a character class and the next newline, inclusive, are also  unescaped # outside a character class and the next newline, inclusive, are also
669  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 681  comment is a literal newline sequence in
681  happen to represent a newline do not count.  happen to represent a newline do not count.
682  .P  .P
683  This option makes it possible to include comments inside complicated patterns.  This option makes it possible to include comments inside complicated patterns.
684  Note, however, that this applies only to data characters. Whitespace characters  Note, however, that this applies only to data characters. White space characters
685  may never appear within special character sequences in a pattern, for example  may never appear within special character sequences in a pattern, for example
686  within the sequence (?( that introduces a conditional subpattern.  within the sequence (?( that introduces a conditional subpattern.
687  .sp  .sp
# Line 739  indicated by a single character (CR or L Line 759  indicated by a single character (CR or L
759  PCRE_NEWLINE_CRLF specifies that a newline is indicated by the two-character  PCRE_NEWLINE_CRLF specifies that a newline is indicated by the two-character
760  CRLF sequence. Setting PCRE_NEWLINE_ANYCRLF specifies that any of the three  CRLF sequence. Setting PCRE_NEWLINE_ANYCRLF specifies that any of the three
761  preceding sequences should be recognized. Setting PCRE_NEWLINE_ANY specifies  preceding sequences should be recognized. Setting PCRE_NEWLINE_ANY specifies
762  that any Unicode newline sequence should be recognized. The Unicode newline  that any Unicode newline sequence should be recognized.
763  sequences are the three just mentioned, plus the single characters VT (vertical  .P
764  tab, U+000B), FF (formfeed, U+000C), NEL (next line, U+0085), LS (line  In an ASCII/Unicode environment, the Unicode newline sequences are the three
765  separator, U+2028), and PS (paragraph separator, U+2029). For the 8-bit  just mentioned, plus the single characters VT (vertical tab, U+000B), FF (form
766  library, the last two are recognized only in UTF-8 mode.  feed, U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and PS
767    (paragraph separator, U+2029). For the 8-bit library, the last two are
768    recognized only in UTF-8 mode.
769    .P
770    When PCRE is compiled to run in an EBCDIC (mainframe) environment, the code for
771    CR is 0x0d, the same as ASCII. However, the character code for LF is normally
772    0x15, though in some EBCDIC environments 0x25 is used. Whichever of these is
773    not LF is made to correspond to Unicode's NEL character. EBCDIC codes are all
774    less than 256. For more details, see the
775    .\" HREF
776    \fBpcrebuild\fP
777    .\"
778    documentation.
779  .P  .P
780  The newline setting in the options word uses three bits that are treated  The newline setting in the options word uses three bits that are treated
781  as a number, giving eight possibilities. Currently only six are used (default  as a number, giving eight possibilities. Currently only six are used (default
# Line 753  PCRE_NEWLINE_CR with PCRE_NEWLINE_LF is Line 785  PCRE_NEWLINE_CR with PCRE_NEWLINE_LF is
785  other combinations may yield unused numbers and cause an error.  other combinations may yield unused numbers and cause an error.
786  .P  .P
787  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
788  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,
789  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
790  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
791  other circumstances, line break sequences in patterns are treated as literal  other circumstances, line break sequences in patterns are treated as literal
# Line 819  page. Line 851  page.
851  .sp  .sp
852    PCRE_NO_UTF8_CHECK    PCRE_NO_UTF8_CHECK
853  .sp  .sp
854  When PCRE_UTF8 is set, the validity of the pattern as a UTF-8  When PCRE_UTF8 is set, the validity of the pattern as a UTF-8 string is
855  string is automatically checked. There is a discussion about the  automatically checked. There is a discussion about the
856  .\" HTML <a href="pcreunicode.html#utf8strings">  .\" HTML <a href="pcreunicode.html#utf8strings">
857  .\" </a>  .\" </a>
858  validity of UTF-8 strings  validity of UTF-8 strings
# Line 835  this check for performance reasons, you Line 867  this check for performance reasons, you
867  When it is set, the effect of passing an invalid UTF-8 string as a pattern is  When it is set, the effect of passing an invalid UTF-8 string as a pattern is
868  undefined. It may cause your program to crash. Note that this option can also  undefined. It may cause your program to crash. Note that this option can also
869  be passed to \fBpcre_exec()\fP and \fBpcre_dfa_exec()\fP, to suppress the  be passed to \fBpcre_exec()\fP and \fBpcre_dfa_exec()\fP, to suppress the
870  validity checking of subject strings.  validity checking of subject strings only. If the same string is being matched
871    many times, the option can be safely set for the second and subsequent
872    matchings to improve performance.
873  .  .
874  .  .
875  .SH "COMPILATION ERROR CODES"  .SH "COMPILATION ERROR CODES"
# Line 844  validity checking of subject strings. Line 878  validity checking of subject strings.
878  The following table lists the error codes than may be returned by  The following table lists the error codes than may be returned by
879  \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
880  both compiling functions. Note that error messages are always 8-bit ASCII  both compiling functions. Note that error messages are always 8-bit ASCII
881  strings, even in 16-bit mode. As PCRE has developed, some error codes have  strings, even in 16-bit or 32-bit mode. As PCRE has developed, some error codes
882  fallen out of use. To avoid confusion, they have not been re-used.  have fallen out of use. To avoid confusion, they have not been re-used.
883  .sp  .sp
884     0  no error     0  no error
885     1  \e at end of pattern     1  \e at end of pattern
# Line 926  fallen out of use. To avoid confusion, t Line 960  fallen out of use. To avoid confusion, t
960    72  too many forward references    72  too many forward references
961    73  disallowed Unicode code point (>= 0xd800 && <= 0xdfff)    73  disallowed Unicode code point (>= 0xd800 && <= 0xdfff)
962    74  invalid UTF-16 string (specifically UTF-16)    74  invalid UTF-16 string (specifically UTF-16)
963      75  name is too long in (*MARK), (*PRUNE), (*SKIP), or (*THEN)
964      76  character value in \eu.... sequence is too large
965      77  invalid UTF-32 string (specifically UTF-32)
966  .sp  .sp
967  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
968  be used if the limits were changed when PCRE was built.  be used if the limits were changed when PCRE was built.
# Line 958  below Line 995  below
995  in the section on matching a pattern.  in the section on matching a pattern.
996  .P  .P
997  If studying the pattern does not produce any useful information,  If studying the pattern does not produce any useful information,
998  \fBpcre_study()\fP returns NULL. In that circumstance, if the calling program  \fBpcre_study()\fP returns NULL by default. In that circumstance, if the
999  wants to pass any of the other fields to \fBpcre_exec()\fP or  calling program wants to pass any of the other fields to \fBpcre_exec()\fP or
1000  \fBpcre_dfa_exec()\fP, it must set up its own \fBpcre_extra\fP block.  \fBpcre_dfa_exec()\fP, it must set up its own \fBpcre_extra\fP block. However,
1001    if \fBpcre_study()\fP is called with the PCRE_STUDY_EXTRA_NEEDED option, it
1002    returns a \fBpcre_extra\fP block even if studying did not find any additional
1003    information. It may still return NULL, however, if an error occurs in
1004    \fBpcre_study()\fP.
1005  .P  .P
1006  The second argument of \fBpcre_study()\fP contains option bits. There are three  The second argument of \fBpcre_study()\fP contains option bits. There are three
1007  options:  further options in addition to PCRE_STUDY_EXTRA_NEEDED:
1008  .sp  .sp
1009    PCRE_STUDY_JIT_COMPILE    PCRE_STUDY_JIT_COMPILE
1010    PCRE_STUDY_JIT_PARTIAL_HARD_COMPILE    PCRE_STUDY_JIT_PARTIAL_HARD_COMPILE
1011    PCRE_STUDY_JIT_PARTIAL_SOFT_COMPILE    PCRE_STUDY_JIT_PARTIAL_SOFT_COMPILE
1012  .sp  .sp
1013  If any of these are set, and the just-in-time compiler is available, the  If any of these are set, and the just-in-time compiler is available, the
1014  pattern is further compiled into machine code that executes much faster than  pattern is further compiled into machine code that executes much faster than
1015  the \fBpcre_exec()\fP interpretive matching function. If the just-in-time  the \fBpcre_exec()\fP interpretive matching function. If the just-in-time
1016  compiler is not available, these options are ignored. All other bits in the  compiler is not available, these options are ignored. All undefined bits in the
1017  \fIoptions\fP argument must be zero.  \fIoptions\fP argument must be zero.
1018  .P  .P
1019  JIT compilation is a heavyweight optimization. It can take some time for  JIT compilation is a heavyweight optimization. It can take some time for
# Line 1020  real application there should be tests f Line 1061  real application there should be tests f
1061  Studying a pattern does two things: first, a lower bound for the length of  Studying a pattern does two things: first, a lower bound for the length of
1062  subject string that is needed to match the pattern is computed. This does not  subject string that is needed to match the pattern is computed. This does not
1063  mean that there are any strings of that length that match, but it does  mean that there are any strings of that length that match, but it does
1064  guarantee that no shorter strings match. The value is used by  guarantee that no shorter strings match. The value is used to avoid wasting
1065  \fBpcre_exec()\fP and \fBpcre_dfa_exec()\fP to avoid wasting time by trying to  time by trying to match strings that are shorter than the lower bound. You can
1066  match strings that are shorter than the lower bound. You can find out the value  find out the value in a calling program via the \fBpcre_fullinfo()\fP function.
 in a calling program via the \fBpcre_fullinfo()\fP function.  
1067  .P  .P
1068  Studying a pattern is also useful for non-anchored patterns that do not have a  Studying a pattern is also useful for non-anchored patterns that do not have a
1069  single fixed starting character. A bitmap of possible starting bytes is  single fixed starting character. A bitmap of possible starting bytes is
1070  created. This speeds up finding a position in the subject at which to start  created. This speeds up finding a position in the subject at which to start
1071  matching. (In 16-bit mode, the bitmap is used for 16-bit values less than 256.)  matching. (In 16-bit mode, the bitmap is used for 16-bit values less than 256.
1072    In 32-bit mode, the bitmap is used for 32-bit values less than 256.)
1073  .P  .P
1074  These two optimizations apply to both \fBpcre_exec()\fP and  These two optimizations apply to both \fBpcre_exec()\fP and
1075  \fBpcre_dfa_exec()\fP, and the information is also used by the JIT compiler.  \fBpcre_dfa_exec()\fP, and the information is also used by the JIT compiler.
# Line 1173  variable. Line 1214  variable.
1214  .P  .P
1215  If there is a fixed first value, for example, the letter "c" from a pattern  If there is a fixed first value, for example, the letter "c" from a pattern
1216  such as (cat|cow|coyote), its value is returned. In the 8-bit library, the  such as (cat|cow|coyote), its value is returned. In the 8-bit library, the
1217  value is always less than 256; in the 16-bit library the value can be up to  value is always less than 256. In the 16-bit library the value can be up to
1218  0xffff.  0xffff. In the 32-bit library the value can be up to 0x10ffff.
1219  .P  .P
1220  If there is no fixed first value, and if either  If there is no fixed first value, and if either
1221  .sp  .sp
# Line 1187  starts with "^", or Line 1228  starts with "^", or
1228  -1 is returned, indicating that the pattern matches only at the start of a  -1 is returned, indicating that the pattern matches only at the start of a
1229  subject string or after any newline within the string. Otherwise -2 is  subject string or after any newline within the string. Otherwise -2 is
1230  returned. For anchored patterns, -2 is returned.  returned. For anchored patterns, -2 is returned.
1231    .P
1232    Since for the 32-bit library using the non-UTF-32 mode, this function is unable
1233    to return the full 32-bit range of the character, this value is deprecated;
1234    instead the PCRE_INFO_FIRSTCHARACTERFLAGS and PCRE_INFO_FIRSTCHARACTER values
1235    should be used.
1236  .sp  .sp
1237    PCRE_INFO_FIRSTTABLE    PCRE_INFO_FIRSTTABLE
1238  .sp  .sp
# Line 1234  value, -1 is returned. For anchored patt Line 1280  value, -1 is returned. For anchored patt
1280  only if it follows something of variable length. For example, for the pattern  only if it follows something of variable length. For example, for the pattern
1281  /^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
1282  is -1.  is -1.
1283    .P
1284    Since for the 32-bit library using the non-UTF-32 mode, this function is unable
1285    to return the full 32-bit range of the character, this value is deprecated;
1286    instead the PCRE_INFO_REQUIREDCHARFLAGS and PCRE_INFO_REQUIREDCHAR values should
1287    be used.
1288  .sp  .sp
1289    PCRE_INFO_MAXLOOKBEHIND    PCRE_INFO_MAXLOOKBEHIND
1290  .sp  .sp
1291  Return the number of characters (NB not bytes) in the longest lookbehind  Return the number of characters (NB not bytes) in the longest lookbehind
1292  assertion in the pattern. Note that the simple assertions \eb and \eB require a  assertion in the pattern. Note that the simple assertions \eb and \eB require a
1293  one-character lookbehind. This information is useful when doing multi-segment  one-character lookbehind. This information is useful when doing multi-segment
1294  matching using the partial matching facilities.  matching using the partial matching facilities.
1295  .sp  .sp
1296    PCRE_INFO_MINLENGTH    PCRE_INFO_MINLENGTH
# Line 1273  length of the longest name. PCRE_INFO_NA Line 1324  length of the longest name. PCRE_INFO_NA
1324  entry of the table. This is a pointer to \fBchar\fP in the 8-bit library, where  entry of the table. This is a pointer to \fBchar\fP in the 8-bit library, where
1325  the first two bytes of each entry are the number of the capturing parenthesis,  the first two bytes of each entry are the number of the capturing parenthesis,
1326  most significant byte first. In the 16-bit library, the pointer points to  most significant byte first. In the 16-bit library, the pointer points to
1327  16-bit data units, the first of which contains the parenthesis number. The rest  16-bit data units, the first of which contains the parenthesis number.
1328    In the 32-bit library, the pointer points to 32-bit data units, the first of
1329    which contains the parenthesis number. The rest
1330  of the entry is the corresponding name, zero terminated.  of the entry is the corresponding name, zero terminated.
1331  .P  .P
1332  The names are in alphabetical order. Duplicate names may appear if (?| is used  The names are in alphabetical order. Duplicate names may appear if (?| is used
# Line 1375  is made available via this option so tha Line 1428  is made available via this option so tha
1428  \fBpcreprecompile\fP  \fBpcreprecompile\fP
1429  .\"  .\"
1430  documentation for details).  documentation for details).
1431    .sp
1432      PCRE_INFO_FIRSTCHARACTERFLAGS
1433    .sp
1434    Return information about the first data unit of any matched string, for a
1435    non-anchored pattern. The fourth argument should point to an \fBint\fP
1436    variable.
1437    .P
1438    If there is a fixed first value, for example, the letter "c" from a pattern
1439    such as (cat|cow|coyote), 1 is returned, and the character value can be
1440    retrieved using PCRE_INFO_FIRSTCHARACTER.
1441    .P
1442    If there is no fixed first value, and if either
1443    .sp
1444    (a) the pattern was compiled with the PCRE_MULTILINE option, and every branch
1445    starts with "^", or
1446    .sp
1447    (b) every branch of the pattern starts with ".*" and PCRE_DOTALL is not set
1448    (if it were set, the pattern would be anchored),
1449    .sp
1450    2 is returned, indicating that the pattern matches only at the start of a
1451    subject string or after any newline within the string. Otherwise 0 is
1452    returned. For anchored patterns, 0 is returned.
1453    .sp
1454      PCRE_INFO_FIRSTCHARACTER
1455    .sp
1456    Return the fixed first character value, if PCRE_INFO_FIRSTCHARACTERFLAGS
1457    returned 1; otherwise returns 0. The fourth argument should point to an
1458    \fBuint_t\fP variable.
1459    .P
1460    In the 8-bit library, the value is always less than 256. In the 16-bit library
1461    the value can be up to 0xffff. In the 32-bit library in UTF-32 mode the value
1462    can be up to 0x10ffff, and up to 0xffffffff when not using UTF-32 mode.
1463    .P
1464    If there is no fixed first value, and if either
1465    .sp
1466    (a) the pattern was compiled with the PCRE_MULTILINE option, and every branch
1467    starts with "^", or
1468    .sp
1469    (b) every branch of the pattern starts with ".*" and PCRE_DOTALL is not set
1470    (if it were set, the pattern would be anchored),
1471    .sp
1472    -1 is returned, indicating that the pattern matches only at the start of a
1473    subject string or after any newline within the string. Otherwise -2 is
1474    returned. For anchored patterns, -2 is returned.
1475    .sp
1476      PCRE_INFO_REQUIREDCHARFLAGS
1477    .sp
1478    Returns 1 if there is a rightmost literal data unit that must exist in any
1479    matched string, other than at its start. The fourth argument should  point to
1480    an \fBint\fP variable. If there is no such value, 0 is returned. If returning
1481    1, the character value itself can be retrieved using PCRE_INFO_REQUIREDCHAR.
1482    .P
1483    For anchored patterns, a last literal value is recorded only if it follows
1484    something of variable length. For example, for the pattern /^a\ed+z\ed+/ the
1485    returned value 1 (with "z" returned from PCRE_INFO_REQUIREDCHAR), but for
1486    /^a\edz\ed/ the returned value is 0.
1487    .sp
1488      PCRE_INFO_REQUIREDCHAR
1489    .sp
1490    Return the value of the rightmost literal data unit that must exist in any
1491    matched string, other than at its start, if such a value has been recorded. The
1492    fourth argument should point to an \fBuint32_t\fP variable. If there is no such
1493    value, 0 is returned.
1494  .  .
1495  .  .
1496  .SH "REFERENCE COUNTS"  .SH "REFERENCE COUNTS"
# Line 1471  fields (not necessarily in this order): Line 1587  fields (not necessarily in this order):
1587  .sp  .sp
1588  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
1589  "PCRE_UCHAR16 **".  "PCRE_UCHAR16 **".
1590    .sp
1591    In the 32-bit version of this structure, the \fImark\fP field has type
1592    "PCRE_UCHAR32 **".
1593  .P  .P
1594  The \fIflags\fP field is used to specify which of the other fields are set. The  The \fIflags\fP field is used to specify which of the other fields are set. The
1595  flag bits are:  flag bits are:
# Line 1523  This limit is of use only if it is set s Line 1642  This limit is of use only if it is set s
1642  Limiting the recursion depth limits the amount of machine stack that can be  Limiting the recursion depth limits the amount of machine stack that can be
1643  used, or, when PCRE has been compiled to use memory on the heap instead of the  used, or, when PCRE has been compiled to use memory on the heap instead of the
1644  stack, the amount of heap memory that can be used. This limit is not relevant,  stack, the amount of heap memory that can be used. This limit is not relevant,
1645  and is ignored, when matching is done using JIT compiled code.  and is ignored, when matching is done using JIT compiled code.
1646  .P  .P
1647  The default value for \fImatch_limit_recursion\fP can be set when PCRE is  The default value for \fImatch_limit_recursion\fP can be set when PCRE is
1648  built; the default default is the same value as the default for  built; the default default is the same value as the default for
# Line 1707  causing performance to suffer, but ensur Line 1826  causing performance to suffer, but ensur
1826  "no match", the callouts do occur, and that items such as (*COMMIT) and (*MARK)  "no match", the callouts do occur, and that items such as (*COMMIT) and (*MARK)
1827  are considered at every possible starting position in the subject string. If  are considered at every possible starting position in the subject string. If
1828  PCRE_NO_START_OPTIMIZE is set at compile time, it cannot be unset at matching  PCRE_NO_START_OPTIMIZE is set at compile time, it cannot be unset at matching
1829  time. The use of PCRE_NO_START_OPTIMIZE disables JIT execution; when it is set,  time. The use of PCRE_NO_START_OPTIMIZE disables JIT execution; when it is set,
1830  matching is always done using interpretively.  matching is always done using interpretively.
1831  .P  .P
1832  Setting PCRE_NO_START_OPTIMIZE can change the outcome of a matching operation.  Setting PCRE_NO_START_OPTIMIZE can change the outcome of a matching operation.
# Line 1741  returned. Line 1860  returned.
1860  .sp  .sp
1861  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
1862  string is automatically checked when \fBpcre_exec()\fP is subsequently called.  string is automatically checked when \fBpcre_exec()\fP is subsequently called.
1863  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
1864  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
1865  strings in the  UTF-8 character. There is a discussion about the
1866    .\" HTML <a href="pcreunicode.html#utf8strings">
1867    .\" </a>
1868    validity of UTF-8 strings
1869    .\"
1870    in the
1871  .\" HREF  .\" HREF
1872  \fBpcreunicode\fP  \fBpcreunicode\fP
1873  .\"  .\"
# Line 2099  just-in-time processing stack is not lar Line 2223  just-in-time processing stack is not lar
2223  .\"  .\"
2224  documentation for more details.  documentation for more details.
2225  .sp  .sp
2226    PCRE_ERROR_BADMODE (-28)    PCRE_ERROR_BADMODE        (-28)
2227  .sp  .sp
2228  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
2229  passed to a 16-bit library function, or vice versa.  passed to a 16-bit or 32-bit library function, or vice versa.
2230  .sp  .sp
2231    PCRE_ERROR_BADENDIANNESS (-29)    PCRE_ERROR_BADENDIANNESS  (-29)
2232  .sp  .sp
2233  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
2234  host with different endianness. The utility function  host with different endianness. The utility function
2235  \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
2236  so that it runs on the new host.  so that it runs on the new host.
2237    .sp
2238      PCRE_ERROR_BADLENGTH      (-32)
2239    .sp
2240    This error is given if \fBpcre_exec()\fP is called with a negative value for
2241    the \fIlength\fP argument.
2242  .P  .P
2243  Error numbers -16 to -20 and -22 are not used by \fBpcre_exec()\fP.  Error numbers -16 to -20, -22, 30, and -31 are not used by \fBpcre_exec()\fP.
2244  .  .
2245  .  .
2246  .\" HTML <a name="badutf8reasons"></a>  .\" HTML <a name="badutf8reasons"></a>
# Line 2123  for the 16-bit library is given in the Line 2252  for the 16-bit library is given in the
2252  .\" HREF  .\" HREF
2253  \fBpcre16\fP  \fBpcre16\fP
2254  .\"  .\"
2255    page. The corresponding information for the 32-bit library is given in the
2256    .\" HREF
2257    \fBpcre32\fP
2258    .\"
2259  page.  page.
2260  .P  .P
2261  When \fBpcre_exec()\fP returns either PCRE_ERROR_BADUTF8 or  When \fBpcre_exec()\fP returns either PCRE_ERROR_BADUTF8 or
# Line 2193  character. Line 2326  character.
2326  .sp  .sp
2327  The first byte of a character has the value 0xfe or 0xff. These values can  The first byte of a character has the value 0xfe or 0xff. These values can
2328  never occur in a valid UTF-8 string.  never occur in a valid UTF-8 string.
2329    .sp
2330      PCRE_UTF8_ERR2
2331    .sp
2332    Non-character. These are the last two characters in each plane (0xfffe, 0xffff,
2333    0x1fffe, 0x1ffff .. 0x10fffe, 0x10ffff), and the characters 0xfdd0..0xfdef.
2334  .  .
2335  .  .
2336  .SH "EXTRACTING CAPTURED SUBSTRINGS BY NUMBER"  .SH "EXTRACTING CAPTURED SUBSTRINGS BY NUMBER"
# Line 2629  When a recursive subpattern is processed Line 2767  When a recursive subpattern is processed
2767  recursively, using private vectors for \fIovector\fP and \fIworkspace\fP. This  recursively, using private vectors for \fIovector\fP and \fIworkspace\fP. This
2768  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
2769  extremely rare, as a vector of size 1000 is used.  extremely rare, as a vector of size 1000 is used.
2770    .sp
2771      PCRE_ERROR_DFA_BADRESTART (-30)
2772    .sp
2773    When \fBpcre_dfa_exec()\fP is called with the \fBPCRE_DFA_RESTART\fP option,
2774    some plausibility checks are made on the contents of the workspace, which
2775    should contain data about the previous partial match. If any of these checks
2776    fail, this error is given.
2777  .  .
2778  .  .
2779  .SH "SEE ALSO"  .SH "SEE ALSO"
2780  .rs  .rs
2781  .sp  .sp
2782  \fBpcre16\fP(3), \fBpcrebuild\fP(3), \fBpcrecallout\fP(3), \fBpcrecpp(3)\fP(3),  \fBpcre16\fP(3), \fBpcre32\fP(3), \fBpcrebuild\fP(3), \fBpcrecallout\fP(3),
2783  \fBpcrematching\fP(3), \fBpcrepartial\fP(3), \fBpcreposix\fP(3),  \fBpcrecpp(3)\fP(3), \fBpcrematching\fP(3), \fBpcrepartial\fP(3),
2784  \fBpcreprecompile\fP(3), \fBpcresample\fP(3), \fBpcrestack\fP(3).  \fBpcreposix\fP(3), \fBpcreprecompile\fP(3), \fBpcresample\fP(3),
2785    \fBpcrestack\fP(3).
2786  .  .
2787  .  .
2788  .SH AUTHOR  .SH AUTHOR
# Line 2653  Cambridge CB2 3QH, England. Line 2799  Cambridge CB2 3QH, England.
2799  .rs  .rs
2800  .sp  .sp
2801  .nf  .nf
2802  Last updated: 24 February 2012  Last updated: 29 October 2012
2803  Copyright (c) 1997-2012 University of Cambridge.  Copyright (c) 1997-2012 University of Cambridge.
2804  .fi  .fi

Legend:
Removed from v.950  
changed lines
  Added in v.1191

  ViewVC Help
Powered by ViewVC 1.1.5