The-t parameter of the shutdown command and a bug related to shutdown that occurs frequently

The-t parameter of the shutdown command and a frequently occurring bug related to shutdown-Linux general technology-Linux technology and application information. For more information, see the following. How to use the-t parameter of shutdown?
Reference man seems to be:
Shutdown-t30-r now
In my understanding, the above command should be a shutdown command sent to the terminal 30 seconds later, but it does not actually seem like this!
Press enter to start shutdown.

In addition, in coreora core8, I usually use poweroff to shut down, but every time I press the power key of the host, the screen will be hacked, otherwise there will always be "system halted.
How can I enable automatic shutdown without manually pressing the power button and shutdown-h now?

[ This post was last edited by tobeguru]