Halt the system in Linux without the halt command or gui 

echo o > /proc/sysrq-trigger

August 9, 2011 — bashoneliners

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
system-management
echo