dmesg with colored human-readable dates

With sed it's easy to choose the bash color to use ;34 here for blue.

You can also use grep to highlight the date instead of sed.

dmesg -T| grep --color "^\[.*`date +%Y`\]"

And export the GREP_COLORS variable to change the color.

ex : export GREP_COLORS="fn=34:mc=01;30:ms=33:sl=21:cx=31"

dmesg -T works on my archlinux but on my debian server option -T does not exist.

You can use perl if your dmesg does not support -T :

dmesg|perl -ne "BEGIN{\$a= time()- qx!cat /proc/uptime!};s/\[\s*(\d+)\.\d+\]/localtime(\$1 + \$a)/e; print \$_;" | sed -e 's|\(^.*'`date +%Y`' \)\(.*\)|\x1b[0;34m\1\x1b[0m - \2|g'

Not working on CentOS:

dmesg: invalid option -- T

-T option to dmesg is available on Fedora but not RHEL5/6.

@dynaguy so as said on my previous comment on CentOS you should try :

dmesg|perl -ne "BEGIN{\$a= time()- qx!cat /proc/uptime!};s/\[\s*(\d+)\.\d+\]/localtime(\$1 + \$a)/e; print \$_;" | sed -e 's|\(^.*'`date +%Y`' \)\(.*\)|\x1b[0;34m\1\x1b[0m - \2|g'

If you get the error :

bash: !}: event not found

You need to turn off bash history substitution with : set +H

@jlaunay I just tried on CentOS 6.3 64bit. After "set +H" there is no more error message. But your command still doesn't give time stamp.

Recent CentOS use rsyslog. What I did is edit /etc/rsyslog.conf, add:

kern.* /var/log/kern.log

then "service rsyslog restart"

Now you can view dmesg in file /var/log/kern.log with time/data

@dynaguy Good to know if I have to use CentOS one day.Thks

"dmesg -T" gives:

"dmesg: invalid option -- 'T'

Usage: dmesg [-c] [-n level] [-r] [-s bufsize]"

@mpb you should have a look at the previous comments. I gave an alternative usefull on OS using a dmesg which doesn't support the -T option.

@dynaguy -- no need to turn off bash history substitution. Change the bangs to ':'. The bangs are simply used as delimiters to the qx function, and were simply chosen as a character which wouldn't conflict with all of the other possible delimiters being used in the expression being quoted. Using ':' instead doesn't cause the history substitution problems...

@dynaguy -- no need to turn off bash history substitution. Change the bangs to ':'. The bangs are simply used as delimiters to the qx function, and were simply chosen as a character which wouldn't conflict with all of the other possible delimiters being used in the expression being quoted. Using ':' instead doesn't cause the history substitution problems...

dmesg |ccze -A