1.\" Copyright (c) 1980, 1991 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)halt.8 6.5 (Berkeley) 3/16/91 33.\" 34.Dd March 16, 1991 35.Dt HALT 8 36.Os BSD 4 37.Sh NAME 38.Nm halt 39.Nd stop the processor 40.Sh SYNOPSIS 41.Nm halt 42.Op Fl n 43.Op Fl q 44.Op Fl y 45.Sh DESCRIPTION 46.Nm Halt 47writes out sandbagged information to the disks and then stops 48the processor. The machine does not reboot, even if the auto-reboot 49switch is set on the console. 50.Pp 51Available options for 52.Nm halt : 53.Bl -tag -width Ds 54.It Fl n 55No sync before stopping. 56.It Fl q 57Quick halt, no graceful shutdown is attempted. 58.It Fl y 59This option is needed if you are trying to halt the system from a dialup. 60.El 61.Pp 62.Nm Halt 63normally logs the shutdown using 64.Xr syslog 8 65and places a shutdown record in the login accounting file 66.Pa /var/log/wtmp. 67These actions are inhibited if the 68.Fl n 69or 70.Fl q 71options are present. 72.Sh SEE ALSO 73.Xr reboot 8 , 74.Xr shutdown 8 , 75.Xr syslogd 8 76.Sh BUGS 77It is very difficult to halt a 78.Tn VAX , 79as the machine wants to then 80reboot itself. A rather tight loop suffices. 81.Sh HISTORY 82The 83.Nm 84command appeared in 85.Bx 4.0 . 86