.\" Copyright (c) 1993 Michael Haardt (michael@moria.de),
.\"     Fri Apr  2 11:32:09 MET DST 1993
.\"
.\" This is free documentation; you can redistribute it and/or
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.\" Modified Sat Jul 24 17:00:12 1993 by Rik Faith (faith@cs.unc.edu)
.TH NULL 4 2009-02-23 "Linux" "Linux Programmer's Manual"
.SH NAME
null, zero \- data sink
.SH DESCRIPTION
Data written to a \fBnull\fP or \fBzero\fP special file is discarded.
.PP
Reads from the \fBnull\fP special file always return end of file (i.e.,
.BR read (2)
returns 0), whereas
reads from \fBzero\fP always return bytes containing zero (\e0 characters).
.LP
\fBnull\fP and \fBzero\fP are typically created by:
.RS
.sp
mknod \-m 666 /dev/null c 1 3
.br
mknod \-m 666 /dev/zero c 1 5
.br
chown root:root /dev/null /dev/zero
.RE
.SH FILES
.I /dev/null
.br
.I /dev/zero
.SH NOTES
If these devices are not writable and readable for all users, many
programs will act strangely.
.SH "SEE ALSO"
.BR chown (1),
.BR mknod (1),
.BR full (4)
.SH COLOPHON
This page is part of release 3.22 of the Linux
.I man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.
