Shutting down

Problem

You want to shutdown system, sometimes immediately, sometimes at a certain time or after a certain duration.

Solution

Use the shutdown command with root privilege.

To immediately shut down and halt the system

    sudo shutdown -h now

To immediately reboot the system

    sudo shutdown -r now

You can optionally send a warning message to all user with -c option

    sudo shutdown -h now "The system is being shut down now!"

To shut down the system at a certain time

    # At 4.23 AM
    sudo shutdown -h 4:23

    # At 8.00 PM
    sudo shutdown -h 20:00

To shut down and halt the system after a period of time

    # In 5 minutes
    sudo shutdown -h +5

To cancel a shutdown

    sudo shutdown -c