I have been banging my head against this for quite a while now. It’s related to this question. I would like to find out exactly what happens when I choose to shut down my Linux box from the GUI. This seems to be poorly (if at all) documented.
at 18:00 shutdown now and shutdown 18:00 , are they starting the same service? Do they work the same way?
It seems I can shutdown using sudo shutdown by specifying a time or minutes.
E.g. I’m seeing this in /var/log/messages:
I want to execute a simple command just before the computer shuts down (timing is not essential).
What security risk is posed by not requiring this to have root privileges? The GUI provides a way for any user to shut off or restart, so why do the terminal commands need to be run as root?
When I try to shutdown the computer from a command line or terminal I must have root privileges:
I am using Ubuntu 16.04.
I would like to execute this shell script at reboot and shut down:
Or is shutdown -h now the fastest it can get?