Halt the system in Linux without the halt command or gui

0 
 $ echo o > /proc/sysrq-trigger

Aug. 9, 2011, 9:55 p.m. — Janos

Explanation

  • First you need to enable the sysrq interface with: echo 1 > /proc/sys/kernel/sysrq
  • echo o > /proc/sysrq-trigger halts
  • echo b > /proc/sysrq-trigger reboots