null, zero — data sink
Data written to the /dev/null and /dev/zero special files is discarded.
Reads from /dev/null always
return end of file (i.e., read(2) returns 0), whereas
reads from /dev/zero always
return bytes containing zero ('\0' characters).
These devices are typically created by:
mknod −m 666 /dev/null c 1 3 mknod −m 666 /dev/zero c 1 5 chown root:root /dev/null /dev/zero
If these devices are not writable and readable for all users, many programs will act strangely.
Since Linux 2.6.31, reads from /dev/zero are interruptible by signals.
(This change was made to help with bad latencies for large
reads from /dev/zero.)
This page is part of release 4.16 of the Linux man-pages project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man−pages/.
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Copyright (c) 1993 Michael Haardt (michaelmoria.de), Fri Apr 2 11:32:09 MET DST 1993 %%%LICENSE_START(GPLv2+_DOC_FULL) This is free documentation; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The GNU General Public License's references to "object code" and "executables" are to be interpreted as the output of any document formatting or typesetting system, including intermediate and printed output. This manual is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this manual; if not, see <http://www.gnu.org/licenses/>. %%%LICENSE_END Modified Sat Jul 24 17:00:12 1993 by Rik Faith (faithcs.unc.edu) |