Control the systemd system and service manager. More information: https://www.freedesktop.org/software/systemd/man/systemctl.html.
systemctl status
systemctl --failed
systemctl {{start|stop|restart|reload|status}} {{unit}}
systemctl {{enable|disable}} {{unit}}
systemctl daemon-reload
systemctl {{is-active|is-enabled|is-failed}} {{unit}}
systemctl list-units {{[-t|--type]}} {{service|socket|automount}} --state {{failed|running}}
systemctl cat {{unit}}