HALT(8) Linux System Administrator's Manual HALT(8)
NAMEhalt, reboot, poweroff - stop the system.
SYNOPSIS/sbin/halt [-n] [-w] [-d] [-f] [-i] [-p] /sbin/reboot [-n] [-w] [-d] [-f] [-i] /sbin/poweroff [-n] [-w] [-d] [-f] [-i]
DESCRIPTIONHalt 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, shut down(8) will be invoked instead (with the flag -h or -r).
OPTIONS-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. DIAGNOSTICS If you're not the superuser, you will get the message `must be superuser'.
NOTESUnder 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.
AUTHORMiquel van Smoorenburg, email@example.com
SEE ALSOshutdown(8), init(1) Aug 24, 1999 HALT(8)