Feel extra-geeky by shutting down linux from terminal

This is one of my most favorite tricks, that helps me to reduce the use of mouse. To get started, you just need a mind to learn a new command
 
Press Alt+F2 and type gnome-terminal to bring up terminal, then type in the following command:
"shutdown -option time" where -option can include the following commands
-r Reboot
-P Power the system off (shutdown)
-H Halt the system
-h Halt or power down the system
-c Cancel a shutdown command

eg.1: If you want to shutdown the system with "0" waiting time
"shutdown -P 0"

eg.2" If you want to reboot the system with "0" waiting time
"shutdown -r 0"

NOTE:

0 means 0 minutes, if you enter 1, the time for countdown timer will be 1min

To cancel the shutdown process, you can either bring up another terminal, then type in the command "shutdown -c", or press Ctrl+C in the terminal in which the shutdown command is running