xref: /titanic_50/usr/src/man/man7d/zero.7d (revision 0a70879558a701a07771af87e7852a12f3bfd438)
te
Copyright 1989 AT&T Copyright (c) 1990, Sun Microsystems, Inc. All Rights Reserved
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
ZERO 7D "Jul 3, 1990"
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)