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: src/sbin/dmesg/dmesg.8,v 1.5.2.5 2002/08/21 18:58:17 trhodes Exp $ 34.\" $DragonFly: src/sbin/dmesg/dmesg.8,v 1.2 2003/06/17 04:27:32 dillon Exp $ 35.\" 36.Dd June 5, 1993 37.Dt DMESG 8 38.Os 39.Sh NAME 40.Nm dmesg 41.Nd "display the system message buffer" 42.Sh SYNOPSIS 43.Nm 44.Op Fl a 45.Op Fl M Ar core 46.Op Fl N Ar system 47.Sh DESCRIPTION 48The 49.Nm 50utility displays the contents of the system message buffer. 51If neither the 52.Fl N 53nor the 54.Fl M 55option is specified, the buffer is read from the currently running kernel 56via the 57.Xr sysctl 3 58interface. 59Otherwise, the buffer is read from the specified core file (or from the 60default one), using the name list from the specified kernel image (or from 61the default image). 62.Pp 63The options are as follows: 64.Bl -tag -width indent 65.It Fl a 66Show all data in the message buffer. 67This includes any syslog records and 68.Pa /dev/console 69output. 70.It Fl M 71Extract values associated with the name list from the specified core 72instead of the default 73.Pa /dev/kmem . 74.It Fl N 75Extract the name list from the specified system instead of the default, 76which is the kernel image the system has booted from. 77.El 78.Sh FILES 79.Bl -tag -width ".Pa /var/run/dmesg.boot" -compact 80.It Pa /var/run/dmesg.boot 81usually a snapshot of the buffer contents 82taken soon after file systems are mounted 83at startup time 84.El 85.Sh SEE ALSO 86.Xr sysctl 3 , 87.Xr syslogd 8 88.Sh HISTORY 89The 90.Nm 91utility appeared in 92.Bx 4.0 . 93