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 47The 48.Nm 49utility displays the contents of the system message buffer. 50If neither the 51.Fl N 52nor the 53.Fl M 54option is specified, the buffer is read from the currently running kernel 55via the 56.Xr sysctl 3 57interface. 58Otherwise, the buffer is read from the specified core file (or from the 59default one), using the name list from the specified kernel image (or from 60the default image). 61.Pp 62The options are as follows: 63.Bl -tag -width indent 64.It Fl a 65Show all data in the message buffer. 66This includes any syslog records and 67.Pa /dev/console 68output. 69.It Fl M 70Extract values associated with the name list from the specified core 71instead of the default 72.Pa /dev/kmem . 73.It Fl N 74Extract the name list from the specified system instead of the default, 75which is the kernel image the system has booted from. 76.El 77.Sh FILES 78.Bl -tag -width ".Pa /var/run/dmesg.boot" -compact 79.It Pa /var/run/dmesg.boot 80usually a snapshot of the buffer contents 81taken soon after file systems are mounted 82at startup time 83.El 84.Sh SEE ALSO 85.Xr sysctl 3 , 86.Xr syslogd 8 87.Sh HISTORY 88The 89.Nm 90utility appeared in 91.Bx 4.0 . 92