journalctl

A really neat CLI for linux system logging as explained by howtogeek and linuxhandbook.

  • journalctl

  • journalctl -k kernel only

  • journalctl -u ssh ssh only

  • journalctl -p 3 error only

  • journalctl --no-page

  • journalctl -n 20

  • journalctl -f

  • journalctl -o short-full

  • journalctl -o verbose

  • journalctl -o json

  • journalctl -o json-pretty

  • journalctl --list-boots

  • journalctl -b -2 -2th boot session only

  • journalctl -p 4..6 -b0

  • journalctl -S "2020-12-31 07:00:00" from (accepts various formats like today, yersterday, -1d, …)

  • journalctl -S "2020-12-31 07:00:00" -U 2021-01-15 from to

  • journalctl --disk-usage

Priorities

| Priority | Code | |:——–:|:——:| | 0 | emerg | | 1 | alert | | 2 | crit | | 3 | err | | 4 | warning | | 5 | notice | | 6 | info | | 7 | debug |