reboot

This command triggers the reboot procedure.

Interface

reboot [ -h ] [ -a ] [ -f|F ] [ -m message ] [ -t time ] [ -W ] when

This command triggers the reboot procedure immediately if when is omitted.

The when provided must be on these formats:

now: triggers the reboot sequence immediately. This is the default
mins or +mins : relative time; triggers the reboot sequence after mins minutes.
hh:mm : absolute time; triggers the reboot sequence when the time hh:mm occurs. If that time has passed for the current day, it will wait for the next day. hh can have 1 or 2 digits; mm must have 2 digits.

-h: print this help.
-a: use access control. The reboot sequence will only be launched if one of the users listed in /etc/66/shutdown.allow is currently logged in (as tracked by utmp). /etc/66/shutdown.allow is a text file which accepts one user per line. Lines starting with # are commented out.
-f: do not trigger a clean shutdown procedure; it will just sync the filesystems then tell the kernel to immediately reboot. This should be the last step in the lifetime of the machine.
-F: same as -f but do not sync the filesystems.
-m message: replace the default message by message. message is broadcast to all logged in users (as tracked by utmp).
-t time: have a grace time period of time seconds between the SIGTERM and the SIGKILL at the end of the reboot sequence when it is time to kill all processes (allows processes to receive SIGTERM to exit cleanly). The default is 3 seconds.
-W: do not send a wall message to users.

reboots the system.

66 reboot

reboots a broken system

66 reboot -f

reboots the system after 10 minutes

66 reboot 10

Sends an "system will be rebooted in 10 minutes" to connected account and reboot the system after 10 minutes

66 reboot -m "system will be rebooted in 10 minutes" 10