The
fwide() function determines the orientation of the stream pointed at by
stream.
If the orientation of
stream has already been determined,
fwide() leaves it unchanged. Otherwise,
fwide() sets the orientation of
stream according to
mode.
If
mode is less than zero,
stream is set to byte-oriented. If it is greater than zero,
stream is set to wide-oriented. Otherwise,
mode is zero, and
stream is unchanged.