Systemd keeps track of all users who are logged into the system (e.g. on a virtual console or remotely via SSH). The command <command>loginctl</command> allows querying and manipulating user sessions. For instance, to list all user sessions:
This shows that two users are logged in locally, while another is logged in remotely. (“Seats” are essentially the combinations of displays and input devices attached to the system; usually, there is only one seat.) To get information about a session:
This shows that the user is logged in on virtual console 3. It also lists the processes belonging to this session. Since systemd keeps track of this, you can terminate a session in a way that ensures that all the session’s processes are gone:
