Run this out of root cron to shut down inactive server

shutdown_if_idle.sh

#!/bin/bash

# true if console users are idle or non-existant
function no_active_users()
{
  if [ `w -sh | sed 's/\s\{1,\}/\t/g' | cut -f4 | egrep '^[0-9\:\.s]+$' | wc -l` -eq 0 ]
  then
    return 0
  fi
  return 1
}

# true if 1, 5, and 15 minute load averages are all 0.00
function no_active_process()
{
  cut -d' ' -f1,2,3 /proc/loadavg >> /tmp/idlr
  if [[ `cut -d' ' -f1,2,3 /proc/loadavg` == '0.00 0.00 0.00' ]]
  then
    return 0
  fi
  return 1
}

if no_active_users
then
  if no_active_process
  then
    shutdown -h now
  fi
fi