int wctomb(char *str
Examines the code which corresponds to a multibyte character
given by the argument wchar. The code is converted to a
multibyte character and stored into the string pointed to by the
argument str if str is not null.
If str is a null pointer, then zero is returned if
multibyte characters are not state-dependent (shift state).
Otherwise a nonzero value is returned if multibyte character are
If str is not null, then the number of bytes that are
contained in the multibyte character wchar are returned. A value
of -1 is returned if wchar is not a valid multibyte character.