Reads input from an array of wide characters under control of a
    wide-character format string.

    Format

      #include  <wchar.h>

      int vwscanf  (const wchar_t *format, va_list ap);

1 - Arguments

 format

    A pointer to a wide-character string containing the format
    specifications.

 ap

    A list of expressions whose resultant types correspond to the
    conversion specifications given in the format specifications.

2 - Description

    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.

3 - Return Values

    n                  The number of wide characters read.
    EOF                Indicates that a read error occurred before
                       any conversion. The function sets errno. For a
                       list of the values set by this function, see
                       vfscanf.