#!/bin/bash

usage(){
	echo "Usage: `basename $0` file_name -gt|-lt time_in_seconds"
	exit 1
}


complt() {
    if [ $difference -lt $max_diff ]; then
	echo "Service OK, time difference is: $difference"
	exit 0
    else
	echo "Service CRITICAL, time difference is: $difference"
	exit 2
    fi
}

compgt() {
    if [ $difference -gt $max_diff ]; then
	echo "Service OK, time difference is: $difference"
	exit 0
    else
	echo "Service CRITICAL, time difference is: $difference"
	exit 2
    fi
}

[ $# -lt 3 ] && usage
[ ! -f $1 ] && echo "file $1 not found !" && exit 1

case $2 in
    -gt)
	crit='gt'
	max_diff=$3
    ;;
    -lt)
	crit='lt'
	max_diff=$3
    ;;
    *)
	usage
    ;;
esac

if [ -z $max_diff ]; then 
    usage
fi

ctime=`date +%s`
ftime=`stat -c %Y $1`
difference=$(($ctime - $ftime))

if [ $crit == 'gt' ]; then
    compgt
elif [ $crit == 'lt' ]; then
    complt
fi
exit 0