ZERO(7D) Devices ZERO(7D)


NAME


zero - source of zeroes

DESCRIPTION


A zero special file is a source of zeroed unnamed memory.


Reads from a zero special file always return a buffer full of zeroes. The
file is of infinite length.


Writes to a zero special file are always successful, but the data written
is ignored.


Mapping a zero special file creates a zero-initialized unnamed memory
object of a length equal to the length of the mapping and rounded up to
the nearest page size as returned by sysconf. Multiple processes can
share such a zero special file object provided a common ancestor mapped
the object MAP_SHARED.

FILES


/dev/zero


SEE ALSO


fork(2), mmap(2), sysconf(3C)


July 3, 1990 ZERO(7D)