I recently ran into an issue where I was trying to troubleshoot a problem with power management in Linux. I wanted to see the most recent entries to see whether the power management feature that I was looking for was working or not. I had to query Linux’s systemd which is in charge of the system and services in Linux.

In order to query Linux’s systemd, you will need to use journalctl. For example, If you want to get yesterday’s entries, do the following:

journalctl -f --since yesterday

-f stands for follow.

Get entries for the last hour:

journalctl -f --since "1 hour ago"

To pause the output, just add | more:

journalctl -f --since yesterday | more

journalctl -f --since "1 hour ago" | more