.\" Copyright 1993 Rickard E. Faith (faith@cs.unc.edu) .\" May be distributed under the GNU General Public License .TH DMESG 8 "28 October 1993" "Linux 0.99" "Linux Programmer's Manual" .SH NAME dmesg \- print or control the kernel ring buffer .SH SYNOPSIS .BI "dmesg [ \-c ] [ \-n " level " ]" .SH DESCRIPTION .B dmesg is used to examine or control the kernel ring buffer. The program helps users to print out their bootup messages. Instead of copying the messages by hand, the user need only: .RS dmesg > boot.messages .RE and mail the .I boot.messages file to whoever can debug their problem. .SH OPTIONS .TP .B \-c clear the ring buffer contents after printing. .TP .BI \-n level set the .I level at which logging of messages is done to the console. For example, .B \-n 1 prevents all messages, expect panic messages, from appearing on the console. All levels of messages are still written to .IR /proc/kmsg , so .BR syslogd (8) can still be used to control exactly where kernel messages appear. When the .B \-n option is used, .B dmesg will .I not print or clear the kernel ring buffer. When both options are used, only the last option on the command line will have an effect. .SH SEE ALSO .BR syslogd (8) .SH AUTHOR Theodore Ts'o (tytso@athena.mit.edu)