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 
.Vt 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 
.Vt mbstate_t argument,  ps, is used to keep track of the shift state. If it is  NULL,  mbrtowc uses an internal, static 
.Vt mbstate_t object, which is initialized to the initial conversion state at program startup.  
RETURN VALUES
 The  mbrtowc functions returns: