ZERO(4D) Devices 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)