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 Op Fl N Ar system 45.Sh DESCRIPTION 46The 47.Nm 48utility displays the contents of the system message buffer. 49If the 50.Fl M 51option is not specified, the buffer is read from the currently running kernel 52via the 53.Xr sysctl 3 54interface. 55Otherwise, the buffer is read from the specified core file, 56using the name list from the specified kernel image (or from 57the default image). 58.Pp 59The options are as follows: 60.Bl -tag -width indent 61.It Fl a 62Show all data in the message buffer. 63This includes any syslog records and 64.Pa /dev/console 65output. 66.It Fl M 67Extract values associated with the name list from the specified core. 68.It Fl N 69If 70.Fl M 71is also specified, 72extract the name list from the specified system instead of the default, 73which is the kernel image the system has booted from. 74.El 75.Sh FILES 76.Bl -tag -width ".Pa /var/run/dmesg.boot" -compact 77.It Pa /var/run/dmesg.boot 78usually a snapshot of the buffer contents 79taken soon after file systems are mounted 80at startup time 81.El 82.Sh SEE ALSO 83.Xr sysctl 3 , 84.Xr syslogd 8 85.Sh HISTORY 86The 87.Nm 88utility appeared in 89.Bx 4.0 . 90