#!/bin/bash

kvmstatdir="/sys/kernel/debug/kvm"
duration=2
summode="no"
lph=20
line=-1
if [ $summode = "no" ]
then
	declare -a values
	counter=0
	for i in `ls $kvmstatdir`
	do
		values[$counter]=0
		counter=`expr $counter + 1`
	done
fi

kvmstat_header() {
	for i in `ls $kvmstatdir`
	do
		printf "|%16s " $i
	done
	printf "|\n"
}

USAGE="Usage: `basename $0` [-d arg] [-l arg] [-hs]"
while getopts hvsd:l: OPT; do
    case "$OPT" in
	h)	echo $USAGE
		echo "d - sleep between reported lines"
		echo "l - number of lines betweeen headers"
		echo "s - summary mode (default is difference since last print)"
		exit 0
		;;
	v)	echo "`basename $0` version 0.1"
		exit 0
		;;
	d)	duration=$OPTARG
		;;
	l)	lph=$OPTARG
		;;
	s)	summode="yes"
		;;
	\?)	# getopts issues an error message
		echo $USAGE >&2
		exit 1
		;;
    esac
done

while true
do
	line=`expr $line + 1`
	line=`expr $line % $lph`
	if [ $line -eq "0" ]
	then
		kvmstat_header
	fi

	counter=0
	for i in `ls $kvmstatdir`
	do
		val=`cat $kvmstatdir/$i`
		if [ $summode = "no" ]
		then
			cval=$val;
			val=`expr $cval - ${values[$counter]}`
			values[$counter]=$cval
			counter=`expr $counter + 1`	
		fi
        	printf "|%16d " $val
	done
	printf "|\n"

	sleep $duration
done