osf1 man page for zero

zero(7) 						 Miscellaneous Information Manual						   zero(7)

NAME
       zero - source of zeroes

DESCRIPTION
       This  is  a special file that provides a means of obtaining zeroes.  A read from a zero special file returns a buffer full of zeroes.  This
       file is of infinite length.  Writes to a zero special file succeed at all times, but the data written is ignored.

       If you choose to map to a zero special file, a zero-initialized unnamed memory object is created that is of length equal to the mapping and
       rounded up to the nearest page size returned by the sysconf function.

       A zero special file object can be shared by several processes as long as a common ancestor has mapped the object as MAP_SHARED.

NOTES
       Note that this version of the operating system does not support remapping of currently mapped pages.

FILES
       /dev/zero

SEE ALSO
       Functions: fork(2), mmap(2), sysconf(3).  delim off

																	   zero(7)