.\"	$OpenBSD: dmesg.8,v 1.16 2015/03/13 16:15:08 deraadt Exp $
.\"	$NetBSD: dmesg.8,v 1.9 1995/03/18 14:54:47 cgd Exp $
.\"
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.\"     @(#)dmesg.8	8.1 (Berkeley) 6/5/93
.\"
.Dd $Mdocdate: March 13 2015 $
.Dt DMESG 8
.Os
.Sh NAME
.Nm dmesg
.Nd display the system message buffer
.Sh SYNOPSIS
.Nm dmesg
.Op Fl s
.Op Fl M Ar core
.Op Fl N Ar system
.Sh DESCRIPTION
.Nm
displays the contents of the system message buffer.
It is most commonly used to review system startup messages.
On some systems the message buffer can survive reboot and be
retained (in the hope of exposing information from a crash).
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl M Ar core
Extract values associated with the name list from the specified
.Ar core
instead of the default
.Pa /dev/kmem .
.It Fl N Ar system
Extract the name list from the specified
.Ar system
instead of the default
.Pa /bsd .
.It Fl s
Display the contents of the console message buffer instead.
This can be used to review
.Xr rc 8
system startup messages.
This option is limited to the superuser.
.El
.Sh FILES
.Bl -tag -width /var/run/dmesg.boot -compact
.It Pa /var/run/dmesg.boot
copy of
.Nm
saved by
.Xr rc 8
at boot time
.El
.Sh SEE ALSO
.Xr syslogd 8
.Sh HISTORY
The
.Nm
command appeared in
.Bx 4.0 .