How do you reboot using ubuntu?

Answer 1

The same as with pretty much any other Linux distribution available.

As root or superuser do one of the following:

To initiate an immediate reboot:

# /sbin/reboot

To shut down system and poweroff:

# /sbin/poweroff

To have the machine reboot itself in 37 minutes thus giving me time to log off and drive to my girlfriend's house before the reboot:

# echo "/sbin/reboot"|at now + 37 min

# exit

NOTE: The above assumes the atd daemon is running on the system of course.

The above lists only three (3) of the possible reboot techniques, root can improvise nearly as many other possible scenarios as the imagination is capable of producing. You could configure it to reboot whenever a specific user logs in, or reboot whenever a particular program is executed or reboot whenever some particular file is opened and so on nearly ad infinitum...