#!/bin/bash
#******************************************************************
# Script: acmon
# Author: matt
# Purpose: checks if ac power gone from xo and schedules shutdown. 
# If the ac power is restored and there is a shutdown in progress 
# then the shutdown will be cancelled
# Should be run from /etc/crontab as follows :
# 00,10,20,30,40,50 * * * * root /usr/local/bin/acmon
# NOTE the cron interval needs to less than the SHTDWNTIME
# so that the server picks up if the power is back down
  
# Versions:
# 0.1	04/04/08	Initial					Matt
# 0.2   05/04/08	added -h switch to shudown		Matt
#******************************************************************

# Length of time before shutdown
SHTDWNTIME=15

# if there is no ac power 
if [ $(cat /sys/class/power_supply/olpc-ac/online) = 0 ]; then 
  
  # if there no shutdown in progress then schedule on in 15 mins 
  pgrep shutdown >/dev/null 2>&1
  if [ $? -ne 0 ]; then
    shutdown -h $SHTDWNTIME "power failed" >/dev/null 2>&1 &
    logger -p info "acmon: Shutting down in $SHTDWNTIME minutes due to ac pwr failure"
  else
    logger -p info "acmon: No ac power and shutdown already in progress"
  fi 
else
  # if there is ac power and a shutdown in progress cancel it... 
  pgrep shutdown >/dev/null 2>&1
  if [ $? -eq 0 ]; then
    shutdown -c >/dev/null 2>&1
    logger -p info "acmon: Cancelling shutdown due to ac pwr restore" 
  fi
fi