PCRE(3)                    Library Functions Manual                    PCRE(3)

       PCRE - Perl-compatible regular expressions

       #include <pcre.h>


       pcre32 *pcre32_compile(PCRE_SPTR32 pattern, int options,
            const char **errptr, int *erroffset,
            const unsigned char *tableptr);

       pcre32 *pcre32_compile2(PCRE_SPTR32 pattern, int options,
            int *errorcodeptr,
            const unsigned char *tableptr);

       pcre32_extra *pcre32_study(const pcre32 *code, int options,
            const char **errptr);

       void pcre32_free_study(pcre32_extra *extra);

       int pcre32_exec(const pcre32 *code, const pcre32_extra *extra,
            PCRE_SPTR32 subject, int length, int startoffset,
            int options, int *ovector, int ovecsize);

       int pcre32_dfa_exec(const pcre32 *code, const pcre32_extra *extra,
            PCRE_SPTR32 subject, int length, int startoffset,
            int options, int *ovector, int ovecsize,
            int *workspace, int wscount);


       int pcre32_copy_named_substring(const pcre32 *code,
            PCRE_SPTR32 subject, int *ovector,
            int stringcount, PCRE_SPTR32 stringname,
            PCRE_UCHAR32 *buffer, int buffersize);

       int pcre32_copy_substring(PCRE_SPTR32 subject, int *ovector,
            int stringcount, int stringnumber, PCRE_UCHAR32 *buffer,
            int buffersize);

       int pcre32_get_named_substring(const pcre32 *code,
            PCRE_SPTR32 subject, int *ovector,
            int stringcount, PCRE_SPTR32 stringname,
            PCRE_SPTR32 *stringptr);

       int pcre32_get_stringnumber(const pcre32 *code,
            PCRE_SPTR32 name);

       int pcre32_get_stringtable_entries(const pcre32 *code,
            PCRE_SPTR32 name, PCRE_UCHAR32 **first, PCRE_UCHAR32 **last);

       int pcre32_get_substring(PCRE_SPTR32 subject, int *ovector,
            int stringcount, int stringnumber,
            PCRE_SPTR32 *stringptr);

       int pcre32_get_substring_list(PCRE_SPTR32 subject,
            int *ovector, int stringcount, PCRE_SPTR32 **listptr);

       void pcre32_free_substring(PCRE_SPTR32 stringptr);

       void pcre32_free_substring_list(PCRE_SPTR32 *stringptr);


       pcre32_jit_stack *pcre32_jit_stack_alloc(int startsize, int maxsize);

       void pcre32_jit_stack_free(pcre32_jit_stack *stack);

       void pcre32_assign_jit_stack(pcre32_extra *extra,
            pcre32_jit_callback callback, void *data);

       const unsigned char *pcre32_maketables(void);

       int pcre32_fullinfo(const pcre32 *code, const pcre32_extra *extra,
            int what, void *where);

       int pcre32_refcount(pcre32 *code, int adjust);

       int pcre32_config(int what, void *where);

       const char *pcre32_version(void);

       int pcre32_pattern_to_host_byte_order(pcre32 *code,
            pcre32_extra *extra, const unsigned char *tables);


       void *(*pcre32_malloc)(size_t);

       void (*pcre32_free)(void *);

       void *(*pcre32_stack_malloc)(size_t);

       void (*pcre32_stack_free)(void *);

       int (*pcre32_callout)(pcre32_callout_block *);


       int pcre32_utf32_to_host_byte_order(PCRE_UCHAR32 *output,
            PCRE_SPTR32 input, int length, int *byte_order,
            int keep_boms);


       Starting  with  release  8.32, it is possible to compile a PCRE library
       that supports 32-bit character strings, including  UTF-32  strings,  as
       well as or instead of the original 8-bit library. This work was done by
       Christian Persch, based on the work done  by  Zoltan  Herczeg  for  the
       16-bit  library.  All  three  libraries contain identical sets of func-
       tions, used in exactly the same way.  Only the names of  the  functions
       and  the  data  types  of their arguments and results are different. To
       avoid over-complication and reduce the documentation maintenance  load,
       most  of  the PCRE documentation describes the 8-bit library, with only
       occasional references to the 16-bit and 32-bit libraries. This page de-
       scribes what is different when you use the 32-bit library.

       WARNING:  A  single  application  can  be linked with all or any of the
       three libraries, but you must take care when processing any  particular
       pattern  to  use  functions  from just one library. For example, if you
       want to study a pattern that was compiled  with  pcre32_compile(),  you
       must do so with pcre32_study(), not pcre_study(), and you must free the
       study data with pcre32_free_study().


       There is only one header file, pcre.h. It contains prototypes  for  all
       the functions in all libraries, as well as definitions of flags, struc-
       tures, error codes, etc.


       In Unix-like systems, the 32-bit library is called libpcre32,  and  can
       normally  be  accesss  by adding -lpcre32 to the command for linking an
       application that uses PCRE.


       In the 8-bit library, strings are passed to PCRE library  functions  as
       vectors  of  bytes  with  the  C  type "char *". In the 32-bit library,
       strings are passed as vectors of unsigned 32-bit quantities. The  macro
       PCRE_UCHAR32 specifies an appropriate data type, and PCRE_SPTR32 is de-
       fined as "const PCRE_UCHAR32 *". In very many  environments,  "unsigned
       int" is a 32-bit data type. When PCRE is built, it defines PCRE_UCHAR32
       as "unsigned int", but checks that it really is a 32-bit data type.  If
       it is not, the build fails with an error message telling the maintainer
       to modify the definition appropriately.


       The types of the opaque structures that are used  for  compiled  32-bit
       patterns  and  JIT stacks are pcre32 and pcre32_jit_stack respectively.
       The  type  of  the  user-accessible  structure  that  is  returned   by
       pcre32_study()  is  pcre32_extra, and the type of the structure that is
       used for passing data to a callout  function  is  pcre32_callout_block.
       These structures contain the same fields, with the same names, as their
       8-bit counterparts. The only difference is that pointers  to  character
       strings are 32-bit instead of 8-bit types.


       For  every function in the 8-bit library there is a corresponding func-
       tion in the 32-bit library with a name that starts with pcre32_ instead
       of  pcre_.  The  prototypes are listed above. In addition, there is one
       extra function, pcre32_utf32_to_host_byte_order(). This  is  a  utility
       function  that converts a UTF-32 character string to host byte order if
       necessary. The other 32-bit  functions  expect  the  strings  they  are
       passed to be in host byte order.

       The input and output arguments of pcre32_utf32_to_host_byte_order() may
       point to the same address, that is, conversion in place  is  supported.
       The output buffer must be at least as long as the input.

       The  length  argument  specifies the number of 32-bit data units in the
       input string; a negative value specifies a zero-terminated string.

       If byte_order is NULL, it is assumed that the string starts off in host
       byte  order. This may be changed by byte-order marks (BOMs) anywhere in
       the string (commonly as the first character).

       If byte_order is not NULL, a non-zero value of the integer to which  it
       points  means  that  the input starts off in host byte order, otherwise
       the opposite order is assumed. Again, BOMs in  the  string  can  change
       this. The final byte order is passed back at the end of processing.

       If  keep_boms  is  not  zero,  byte-order  mark characters (0xfeff) are
       copied into the output string. Otherwise they are discarded.

       The result of the function is the number of 32-bit  units  placed  into
       the  output  buffer,  including  the  zero terminator if the string was


       The lengths and starting offsets of subject strings must  be  specified
       in  32-bit  data units, and the offsets within subject strings that are
       returned by the matching functions are in also 32-bit units rather than


       The  name-to-number translation table that is maintained for named sub-
       patterns uses 32-bit characters.  The  pcre32_get_stringtable_entries()
       function returns the length of each entry in the table as the number of
       32-bit data units.


       There   are   two   new   general   option   names,   PCRE_UTF32    and
       PCRE_NO_UTF32_CHECK,     which     correspond    to    PCRE_UTF8    and
       PCRE_NO_UTF8_CHECK in the 8-bit library. In fact, these new options de-
       fine the same bits in the options word. There is a discussion about the
       validity of UTF-32 strings in the pcreunicode page.

       For the pcre32_config() function there is an  option  PCRE_CONFIG_UTF32
       that  returns  1  if UTF-32 support is configured, otherwise 0. If this
       option  is  given  to  pcre_config()  or  pcre16_config(),  or  if  the
       PCRE_CONFIG_UTF8  or  PCRE_CONFIG_UTF16  option is given to pcre32_con-
       fig(), the result is the PCRE_ERROR_BADOPTION error.


       In 32-bit mode, when  PCRE_UTF32  is  not  set,  character  values  are
       treated in the same way as in 8-bit, non UTF-8 mode, except, of course,
       that they can range from 0 to 0x7fffffff instead of 0 to 0xff.  Charac-
       ter  types for characters less than 0xff can therefore be influenced by
       the locale in the same way as before.   Characters  greater  than  0xff
       have only one case, and no "type" (such as letter or digit).

       In  UTF-32  mode,  the  character  code  is  Unicode, in the range 0 to
       0x10ffff, with the exception of values in the range  0xd800  to  0xdfff
       because those are "surrogate" values that are ill-formed in UTF-32.

       A  UTF-32 string can indicate its endianness by special code knows as a
       byte-order mark (BOM). The PCRE functions do not handle this, expecting
       strings   to   be  in  host  byte  order.  A  utility  function  called
       pcre32_utf32_to_host_byte_order() is provided to help  with  this  (see


       The  error  PCRE_ERROR_BADUTF32  corresponds  to its 8-bit counterpart.
       The error PCRE_ERROR_BADMODE is given when a compiled pattern is passed
       to  a  function that processes patterns in the other mode, for example,
       if a pattern compiled with pcre_compile() is passed to pcre32_exec().

       There are new error codes whose names begin with PCRE_UTF32_ERR for in-
       valid  UTF-32  strings,  corresponding  to  the PCRE_UTF8_ERR codes for
       UTF-8 strings that are described in the section entitled "Reason  codes
       for  invalid UTF-8 strings" in the main pcreapi page. The UTF-32 errors

         PCRE_UTF32_ERR1  Surrogate character (range from 0xd800 to 0xdfff)
         PCRE_UTF32_ERR2  Non-character
         PCRE_UTF32_ERR3  Character > 0x10ffff


       If there is an error while compiling a pattern, the error text that  is
       passed  back by pcre32_compile() or pcre32_compile2() is still an 8-bit
       character string, zero-terminated.


       The subject and mark fields in the callout block that is  passed  to  a
       callout function point to 32-bit vectors.


       The  pcretest  program continues to operate with 8-bit input and output
       files, but it can be used for testing the 32-bit library. If it is  run
       with the command line option -32, patterns and subject strings are con-
       verted from 8-bit to 32-bit before being passed to PCRE, and the 32-bit
       library  functions  are used instead of the 8-bit ones. Returned 32-bit
       strings are converted to 8-bit for output. If both the  8-bit  and  the
       16-bit libraries were not compiled, pcretest defaults to 32-bit and the
       -32 option is ignored.

       When PCRE is being built, the RunTest script that is  called  by  "make
       check"  uses  the  pcretest  -C  option to discover which of the 8-bit,
       16-bit and 32-bit libraries has been built, and runs the  tests  appro-


       Not all the features of the 8-bit library are available with the 32-bit
       library. The C++ and POSIX wrapper functions support only the 8-bit li-
       brary, and the pcregrep program is at present 8-bit only.


       Philip Hazel
       University Computing Service
       Cambridge CB2 3QH, England.


       Last updated: 12 May 2013
       Copyright (c) 1997-2013 University of Cambridge.

PCRE 8.33                         12 May 2013                          PCRE(3)
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