#!/bin/bash
usage() {
    echo "Usage: $0 [-p | --pidfile] [-n | --number (of PID)] [-w |--warning (level in percentage, without %)] [-c |--critical (level in percentage, without %)]"
    exit 1
}

if [ $# -eq 0 ]; then
    echo "No arguments supplied"
    usage
fi
while [[ $# -gt 0 ]]; do
    case $1 in
        --pidfile | -p)
            pidfile=$2
            shift
	    shift	
            ;;
        --warning | -w)
            warnval=$2
            shift
            shift
            ;;
        --critical | -c)
            critval=$2
            shift
            shift
            ;;
	--number | -n)
	    pidnumber=$2
	    shift
	    shift
	    ;;
        *)
            echo "Unknown argument: $1"
            usage
            exit 1
            ;;
    esac
done

#######Error Checking Section########
if [ -z "$pidnumber" ] && [ -z "$pidfile" ]
then
echo "No PID number or PID file specified! Use -p|--pidfile or -n|--number to specify process."
usage
exit 2;
elif [ ! -z "$pidnumber" ]
then
proc=$pidnumber
else [ ! -z "$pidfile" ]
proc=`cat $pidfile`
fi
if [ -z "$critval" ] && [ -z "$warnval" ]
then
echo "You must specify a warning and critical value in numeric percentage format"
usage
exit 2;
elif [ -z "$critval" ]
then
echo "You must specify a critical value in number percentage format (e.g. -c 40)" 
usage
exit 2;
elif [ -z "$warnval" ]
then
echo "You must specify a warning value in number percentage format (e.g. -w 40)"
usage
exit 2;
fi

if [ $warnval -ge "$critval" ]
then
echo "Your critical value must be set higher than your warning value."
usage
exit 2;
fi


###########Process the PID, RSS, and Size################# 
line=`prstat -p $proc -n 20 1 1 | grep . | tail -2 | head -1`
process=`echo $line | awk '{ print $10 }' | cut -d\/ -f1`
pid=`echo "$line" | awk '{ print $1 }'`
rss=`echo "$line" | awk '{ print $4 }'` 
size=`echo "$line" | awk '{ print $3 }'` 
rss1=`echo "$rss" | cut -dM -f1` 
size1=`echo "$size" | cut -dM -f1` ###these only work with Mb, not Kb
perc=$(perl -e "print $rss1*100/$size1") ###use perl to calc the percentage of rss/size
roundedperc=$(printf "%.0f\n" "$perc") ### round it to a nice whole number

###### Status Checking and Output #########################
if [ $roundedperc -ge "$critval" ]; then
msg="CRITICAL: Process $process, PID $pid is running at $roundedperc%, which is over $critval%!!!!!"
echo $msg
exit 2; 
elif [ $roundedperc -gt "$warnval" ]; then 
msg="WARNING STATE: Process $process, PID $pid is running $roundedperc%, which is over $warnval% warning level!!" 
echo $msg
exit 1; 
else
msg="OK STATE: Process $process, PID $pid is running at $roundedperc%, which is under the $warnval% warning level"
echo "$msg"
exit 0;
fi