ZERO(4D) Devices ZERO(4D)
zero - source of zeroes
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.
/dev/zero
fork(2), mmap(2), sysconf(3C)
July 3, 1990 ZERO(4D)
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(4D)