1.\" Copyright (c) 1980, 1991, 1993 2.\" The Regents of the University of California. 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 acknowledgment: 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.\" @(#)dmesg.8 8.1 (Berkeley) 6/5/93 33.\" $FreeBSD$ 34.\" 35.Dd June 5, 1993 36.Dt DMESG 8 37.Os 38.Sh NAME 39.Nm dmesg 40.Nd "display the system message buffer" 41.Sh SYNOPSIS 42.Nm 43.Op Fl a 44.Op Fl M Ar core 45.Op Fl N Ar system 46.Sh DESCRIPTION 47.Nm Dmesg 48displays the contents of the system message buffer. 49If neither the 50.Fl N 51nor the 52.Fl M 53option is specified, the buffer is read from the currently running kernel 54via the 55.Xr sysctl 3 56interface. 57Otherwise, the buffer is read from the specified core file (or from the 58default one), using the name list from the specified kernel image (or from 59the default image). 60.Pp 61The options are as follows: 62.Bl -tag -width indent 63.It Fl a 64Show all data in the message buffer. 65This includes any syslog records and 66.Pa /dev/console 67output. 68.It Fl M 69Extract values associated with the name list from the specified core 70instead of the default 71.Pa /dev/kmem . 72.It Fl N 73Extract the name list from the specified system instead of the default, 74which is the kernel image the system has booted from. 75.El 76.Sh FILES 77.Bl -tag -width ".Pa /var/run/dmesg.boot" -compact 78.It Pa /var/run/dmesg.boot 79usually a snapshot of the buffer contents 80taken soon after filesystems are mounted 81at startup time 82.El 83.Sh SEE ALSO 84.Xr sysctl 3 , 85.Xr syslogd 8 86.Sh HISTORY 87The 88.Nm 89command appeared in 90.Bx 4.0 . 91