#!/bin/bash
# Plugin to monitor free ram disk space.
# uses the output of `free` to find the percentage of memory used
#
# Copyright Notice: GPL
# Author: Marian Anderson

if [ $# -ne 4  ] && [ "$1" != "-h" ] ; then
  echo  -e "\nUsage $0 -w <int_value> -c <int_value>\n"
  exit;

fi

if [ "$1" == "-h" ] ; then
 case $1 in
 "-h" )
cat << EOF
  Copyright (c) 2014 Marian Anderson.
  Parameter List :: 
  -w <Memory Warning> = Memory  usage to activate a warning message (eg: -w 90,25 ).
  -c <Memory Critical> = Memory  usage to activate a critical message (eg: -c 95,50 ).
  -h  = This Menu :).
EOF
  ;;
esac
exit;
fi

# Amount of ram that is being used.
used_ram_space=`free | grep Mem | awk '{print $3/$2 * 100.0}' | cut -c1-2`

# Error return values
ok=0;
warning=1;
critical=2;
unknown=3;

if [ $used_ram_space -le $2 ]; then
  echo "OK - $used_ram_space% total used ram"
  exit $ok;
elif [ $used_ram_space -gt $2 ] && [ $used_ram_space -le $4 ]; then
  echo "WARNING - $used_ram_space% total used ram"
  exit $warning
elif [ $used_ram_space -gt $4 ]; then
  echo "CRITICAL - $used_ram_space% total used ram"
  exit $critical
else
  echo "UNKNOWN - $used_ram_space% total used ram"
  exit $unknown
fi


exit;