MBRTOWC

NAME
     mbrtowc, mbrtowc_l -- convert a character to a wide-character code
     (restartable)

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <wchar.h>

     size_t
     mbrtowc(wchar_t * restrict pwc, const char * restrict s, size_t n,
         mbstate_t * restrict ps);

     #include <xlocale.h>

     size_t
     mbrtowc_l(wchar_t * restrict pwc, const char * restrict s, size_t n,
         mbstate_t * restrict ps, locale_t loc);

DESCRIPTION
     The mbrtowc() function inspects at most n bytes pointed to by s to determine
     the number of bytes needed to complete the next multibyte character.
     If a character can be completed, and pwc is not NULL, the wide character
     which is represented by s is stored in the wchar_t it points to.

     If s is NULL, mbrtowc() behaves as if pwc was NULL, s was an empty string
     ("") and n was 1.

     The mbstate_t argument, ps, is used to keep track of the shift state.  If
     it is NULL, mbrtowc() uses an internal, static mbstate_t object, which is
     initialized to the initial conversion state at program startup.

     While the mbrtowc() function uses the current locale, the mbrtowc_l()
     function may be passed a locale directly. See xlocale(3) for more information.
     
RETURN VALUES
     The mbrtowc() functions returns:

     0       The next n or fewer bytes represent the null wide character
             (L'\0').

     >0      The next n or fewer bytes represent a valid character, mbrtowc()
             returns the number of bytes used to complete the multibyte character.
             
     (size_t)-2
             The next n contribute to, but do not complete, a valid multibyte
             character sequence, and all n bytes have been processed.

     (size_t)-1
             An encoding error has occurred.  The next n or fewer bytes do not
             contribute to a valid multibyte character.

ERRORS
     The mbrtowc() function will fail if:

     [EILSEQ]           An invalid multibyte sequence was detected.

     [EINVAL]           The conversion state is invalid.

SEE ALSO
     mbtowc(3), multibyte(3), setlocale(3), wcrtomb(3), xlocale(3)

STANDARDS
     The mbrtowc() function conforms to ISO/IEC 9899:1999 (``ISO C99'').

BSD                              April 8, 2004                             BSD