MBRTOWC(3)             FreeBSD Library Functions Manual             MBRTOWC(3)

NAME
     mbrtowc, mbrtoc16, mbrtoc32 - 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 pc, const char * restrict s, size_t n,
         mbstate_t * restrict ps);

     #include <uchar.h>

     size_t
     mbrtoc16(char16_t * restrict pc, const char * restrict s, size_t n,
         mbstate_t * restrict ps);

     size_t
     mbrtoc32(char32_t * restrict pc, const char * restrict s, size_t n,
         mbstate_t * restrict ps);

DESCRIPTION
     The mbrtowc(), mbrtoc16() and mbrtoc32() functions inspect 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 pc is
     not NULL, the wide character which is represented by s is stored in the
     wchar_t, char16_t or char32_t it points to.

     If s is NULL, these functions behave as if pc 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, these functions use an internal, static mbstate_t object,
     which is initialized to the initial conversion state at program startup.

     As a single char16_t is not large enough to represent certain multibyte
     characters, the mbrtoc16() function may need to be invoked multiple times
     to convert a single multibyte character sequence.

RETURN VALUES
     The mbrtowc(), mbrtoc16() and mbrtoc32() functions return:

     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, these
             functions return the number of bytes used to complete the
             multibyte character.

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

     The mbrtoc16() function also returns:

     (size_t)-3
             The next character resulting from a previous call has been
             stored.  No bytes from the input have been consumed.

ERRORS
     The mbrtowc(), mbrtoc16() and mbrtoc32() functions 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)

STANDARDS
     The mbrtowc(), mbrtoc16() and mbrtoc32() functions conform to ISO/IEC
     9899:2011 ("ISO C11").

FreeBSD 13.1-RELEASE-p6          May 21, 2013          FreeBSD 13.1-RELEASE-p6