pcre32(3) — Linux manual page


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 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.

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

       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 zero-terminated.


       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


       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 above).

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 pcre32_exec().

       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
         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

       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 appropriately.


       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

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 ⟨http://www.pcre.org/⟩.  If you have a bug report for this
       manual page, see
       ⟨http://bugs.exim.org/enter_bug.cgi?product=PCRE⟩.  This page was
       obtained from the tarball pcre-8.45.tar.gz fetched from
       ⟨ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/⟩ on
       2021-08-27.  If you discover any rendering problems in this HTML
       version 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 manual 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)