1.\" $OpenBSD: null.4,v 1.5 2019/08/31 16:26:24 schwarze Exp $ 2.\" $NetBSD: null.4,v 1.3 1994/11/30 16:22:29 jtc Exp $ 3.\" 4.\" Copyright (c) 1991, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)null.4 8.1 (Berkeley) 6/5/93 32.\" 33.Dd $Mdocdate: August 31 2019 $ 34.Dt NULL 4 35.Os 36.Sh NAME 37.Nm null 38.Nd the null device 39.Sh DESCRIPTION 40The 41.Nm 42device accepts and reads data as any ordinary (and willing) file, 43but throws it away. 44The length of the 45.Nm 46device is always zero. 47.Sh FILES 48.Bl -tag -width /dev/null 49.It Pa /dev/null 50.El 51.Sh SEE ALSO 52.Xr zero 4 53.Sh HISTORY 54.Nm 55first appeared in 56.At v4 57as an empty file, 58.Pa /dev/null , 59which returned end of file when being read from. 60An implementation which could also be written to first appeared in 61.At v5 . 62