PCRE(3)                   Library Functions Manual                   PCRE(3)

NAME         top

       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);

THE PCRE 32-BIT LIBRARY         top

       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
       functions, 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 describes 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

THE HEADER FILE         top

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

THE LIBRARY NAME         top

       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.

STRING TYPES         top

       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 defined 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


       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.

32-BIT FUNCTIONS         top

       For every function in the 8-bit library there is a corresponding
       function 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

       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 bytes.


       The name-to-number translation table that is maintained for named
       subpatterns 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.

OPTION NAMES         top

       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
       define 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_config(), 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. Character 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

ERROR NAMES         top

       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

       There are new error codes whose names begin with PCRE_UTF32_ERR for
       invalid 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 are:

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

ERROR TEXTS         top

       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.

CALLOUTS         top

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

TESTING         top

       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 converted 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


       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 library, and the pcregrep program is at present 8-bit only.

AUTHOR         top

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

REVISION         top

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

COLOPHON         top

       This page is part of the PCRE (Perl Compatible Regular Expressions)
       project.  Information about the project can be found at 
       ⟨⟩.  If you have a bug report for this manual
       page, see ⟨⟩.  This
       page was obtained from the tarball pcre-8.41.tar.gz fetched from
       ⟨⟩ on
       2018-02-02.  If you discover any rendering problems in this HTML ver‐
       sion of the page, or you believe there is a better or more up-to-date
       source for the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original man‐
       ual page), send a mail to

PCRE 8.33                        12 May 2013                         PCRE(3)

Pages that refer to this page: pcretest(1)pcreapi(3)pcrepattern(3)