The output of journalctl really looks messy without colors. Is it possible to add colors to its output? On my system it seems only important lines are highlighted. Even dmesg can output with color by adding the --color switch!
6 Answers
The color support of journalctl is documented in man journalctl:
When outputting to a tty, lines are colored according to priority: lines of level ERROR and higher are colored red; lines of level NOTICE and higher are highlighted; other lines are displayed normally.
That's from systemd 229. As seen in the man page, There are no other built-in color controls for journalctl.
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Can have color with
cczeas discussed below serverfault.com/a/836777– Nam G VUCommented Jul 17, 2018 at 3:05 -
1Using different prio does the trick for me. Customised my terminal to display bold in a different color from normal. This gives three colors: prio0,1,2,3 prio 4,5 and prio6,7. Does the trick for me!– gosutoCommented Oct 9, 2018 at 16:40
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5In 2020 there is now, from
man journalctl:SYSTEMD_COLORS=true journalctl --boot > log.ansi– MarcHCommented May 21, 2020 at 6:42
If the original daemon output is already colorized, but the colors are being lost when using journalctl, the --output cat option will restore them. See the manual for more details.
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1This does not work for me and the original logs do have some color and bold formatting. What might I be doing wrong? Commented Nov 27, 2020 at 7:21
Install ccze, then use it like this:
journalctl -b -k -f | ccze [-A] [-o nolookups]
explanation:
-A, --raw-ansi
If one wants to enable raw ANSI color sequences instead of using curses, this option does just that.
-o, --options OPTIONS...
However, lookups is an option that might be better to disable. When on, ccze will try to look up usernames, service
names, and lots of other stuff, which will slow down coloring a great deal. If one is piping a long log through ccze,
this option might be turned off [nolookups] to speed up the process.
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3Please add some more information and examples to your answer. ccze seems like a nice utility but some useful example commands would improve your answer– FrederikCommented Mar 7, 2017 at 15:02
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2While ccze is interesting, this answer drops the colors from journalctl and then asks ccze to guess different colors. The
journalctlflags are unrelated to the question. Look elsewhere.– MarcHCommented May 21, 2020 at 6:45
I use ccze for all the logs.
Example for jornalctl with color.
journalctl -b -k -f | ccze
journalctl -b -k -f | ccze -A
Other examples.
tail -f /etc/nginx/logs/access.log | ccze
tail -f /etc/unbound/unbound.log | ccze
Exporting logs
to export the log to HTML and save it to /root/syslog.html:
ccze -h -o nolookups /root/syslog.html
I hope you find it useful.
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5Please edit this into your other answer on this question. This seems to be a continuation and shouldn't stand on its own. Commented Mar 29, 2017 at 20:36
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Seeking long for the answer, I actually figured out what works for me (with Rails logs and journalctl) – just add --all option.
journalctl -u puma --all
From manpage:
-a, --all Show all fields in full, even if they include unprintable characters or are very long. By default, fields with unprintable characters are abbreviated as "blob data". (Note that the pager may escape unprintable characters again.)
It gives color to log files and command outputs:
ccze -A </etc/nsswitch.conf | catshowsnsswitch.confwith colors, another way could becat /etc/nsswitch.conf | ccze -Atail -f /var/log/syslog | ccze ditto executetail -f /var/log/syslogbut here it shows with colors, another form could beccze -A </var/log/syslog | less -Rccze -A </home/pepe.txt | less -R idem. To run less /home/pepe.txtbut displays it with colors.ccze -h -o nolookups </var/log/syslog> /root/syslog.htmlexports the log to HTML and saves it to/root/syslog.html.
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7Please edit this into your other answer on this question. This seems to be a continuation and shouldn't stand on its own.– chicksCommented Mar 9, 2017 at 2:10
journalctbefore asking.cczetoo slow for me..