Restart /shutdown from a terminal Linux

Open your terminal with CTRL+ALT+T and do these following commands

To shutdown the system:

sudo shutdown -h now

To restart:

sudo reboot

& one more command for restart:

sudo shutdown -r now

Another way For shutdown:

sudo halt

or:

sudo init 0 

For restart:

sudo init 6

You can get more info on the shutdown command by using one of the following:

• shutdown --help
• man shutdown