The vwscanf function is equivalent to the wscanf function, except
    that instead of being called with a variable number of arguments,
    it is called with an argument list (ap) that has been initialized
    by va_start (and possibly with subsequent va_arg calls).

    For more information about format and conversion specifications
    and their corresponding arguments, see the "Understanding Input
    and Output" chapter of the HP C RTL Reference Manual.

    See also wscanf.