Calculate unreferenced memory for a PID

calc_memory.sh

#!/bin/bash

if [ "$1" = "" ]
then
	echo "Pass in a PID"
	exit 1
fi

SMAPS=/proc/$1/smaps

if [ ! -f $SMAPS ]
then
	echo "/proc smaps file not found for PID $1"
	exit 1
fi

cat $SMAPS | awk '
$1 == "Size:" {
	size += $2;
	sunit = $3;
}
$1 == "Referenced:" {
	ref += $2;
	runit = $3;
}
END {
	printf("Total:		%12s %s\n", size, sunit);
	printf("Referenced:	%12s %s\n", ref, runit);
	printf("Unreferenced:	%12s %s\n", (size - ref), runit);
}'