FILE
	/usr/common/sys/exitd.c

NAME
	opposite_direction - take a numerical direction and return the opposite

PROTOTYPE
	int opposite_direction(int direction)

CALLED BY
	Anybody

DESCRIPTION
	Take a numerical direction and return the opposite.  North would
	return south, up would return down, etc.  Some directions may
	not have opposites.

RETURN VALUE
	A numerical direction, or DIR_ERR if the direction isn't recognized,
	or has no opposite.

ERRORS
	Normally none.

SEE ALSO
	get_short_for_dir, get_name_for_dir, direction_by_string