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MBRTOWC(3)               BSD Library Functions Manual               MBRTOWC(3)

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 <wchar.h>
     #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 were NULL, s were an empty string (""), and n were 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 multi-byte multibyte
             byte 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