HALT

halt, reboot, poweroff − stop the system.

/sbin/halt [−n] [−w] [−d] [−f] [−i] [−p]
/sbin/reboot [−n] [−w] [−d] [−f] [−i]
/sbin/poweroff [−n] [−w] [−d] [−f] [−i]

Halt notes that the system is being brought down in the file /var/log/wtmp, and then either tells the kernel to halt, reboot or poweroff the system. If halt or reboot is called when the system is not in runlevel 0 or 6, shutdown(8) will be invoked instead (with the flag -h or -r).

−n

Don’t sync before reboot or halt.

−w

Don’t actually reboot or halt but only write the wtmp record (in the /var/log/wtmp file).

−d

Don’t write the wtmp record. The −n flag implies −d.

−f

Force halt or reboot, don’t call shutdown(8).

−i

Shut down all network interfaces just before halt or reboot.

−p

When halting the system, do a poweroff. This is the default when halt is called as poweroff.

If you’re not the superuser, you will get the message ‘must be superuser’.

Under older sysvinit releases , reboot and halt should never be called directly. From release 2.74 on halt and reboot invoke shutdown(8) if the system is not in runlevel 0 or 6. This means that if halt or reboot cannot find out the current runlevel (for example, when /var/run/utmp hasn’t been initialized correctly) shutdown will be called, which might not be what you want. Use the -f flag if you want to do a hard halt or reboot.

Miquel van Smoorenburg, miquels@cistron.nl

shutdown(8), init(1)