This command will be very usefull if you want to make a maintenance from remote site. With this command it will warn current user that still login, if the computer will be shut down or rebooted within some interval time. I think this command only available in OpenSuse CMIIW.
To do that all you need to do is an root rights so that you can execute this command, here are some of the option:
shutdown -r -F 1 This machine will be rebooted
This will make your machine rebooted within 1 minutes and it will show “This machine will be rebooted” message and do fsck after reboot
shutdown -P 1 This machine will be turned off
This will make your machine power off within 1 minutes and show “This machine will be turned off” message
shutdown -k It’s only a warning
This will only a warning message to all connected user