NULL(4) DragonFly Kernel Interfaces Manual NULL(4)
NAMEnull -- the null device
DESCRIPTIONThe null device accepts and reads data as any ordinary (and willing) file - but throws it away. The length of the null device is always zero.
HISTORYA null device appeared in Version 7 AT&T UNIX. DragonFly 4.9 June 5, 1993 DragonFly 4.9