The
dmesg command is used to display the kernel-related messages on Unix like systems.
Today I will show you how to use this command on the Linux operating system.
Simply use the command:
[mythcat@desk ~]$ dmesg
[ 0.000000] microcode: microcode updated early to revision 0x21, date = 2019-02-13
...
Show the latest message that fits on screen:
[mythcat@desk ~]$ dmesg | less
...
Use it to see infoermation about motherboard:
[mythcat@desk ~]$ dmesg | grep -i memory
...
[mythcat@desk ~]$ dmesg | grep -i dma
...
[mythcat@desk ~]$ dmesg | grep -i usb
...
[mythcat@desk ~]$ dmesg | grep -i tty
...
Same reult with a single command using multiple
grep option:
[mythcat@desk ~]$ dmesg | grep -E "memory|dma|usb|tty"
This display logs related to error and warning:
[root@desk mythcat]# dmesg --level=err,warn
The dmesg comes with supported log facilities:
- kern - kernel messages;
- user - random user-level messages;
- mail - mail system;
- daemon - system daemons;
- auth - security/authorization messages;
- syslog - messages generated internally by syslogd;
- lpr - line printer subsystem;
- news - network news subsystem;
See output facility only for one:
[mythcat@desk ~]$ dmesg --facility=daemon
Use root user to clear dmesg logs after the reading them:
[root@desk mythcat]# dmesg -C
If you want then you can show the outpout into the colored messages:
# dmesg -L
