Reads input from the stream under control of a wide-character
    format string.

    Format

      #include  <wchar.h>

      int vfwscanf  (FILE *stream, const wchar_t *format, va_list

                    ap);

1  –  Arguments

 stream

    A file pointer.

 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 vfwscanf function is equivalent to the fwscanf 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).

    If the stream pointed to by stream has no orientation, vfwscanf
    makes the stream wide-oriented.

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

3  –  Return Values

    n                  The number of successfully matched and
                       assigned wide-character input items.
    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.