How to get information out of the system log files on Linux—showing failed logins.

There are a few ways to extract information from the /var/log files using the Linux command line. Here are a few examples. Show the history of dnf commands on your Linux box with this command. (jcartwright@buddhism) 192.168.1.2 ~ $ grep "dnf in" /var/log/dnf.log 2026-07-21T10:04:04+1000 DDEBUG Command: dnf in brightnessctl 2026-07-27T09:01:01+1000 DDEBUG Command: dnf in cvs […]