Shell Programming and Scripting

#!/bin/bash

MemTotal=`cat /proc/meminfo | grep MemTotal: | awk '{print $2}'`
echo "MemTotal" $MemTotal

Active=`cat /proc/meminfo | grep "^Active:" | awk '{print $2}'`
echo "Active" $Active

UsedFreeMemory=$[$Active/$MemTotal] 
echo "UsedFreeMemory" $UsedFreeMemory

AvailableFreeMemory=$[100-$UsedFreeMemory]
echo "AvailableFreeMemory" $AvailableFreeMemory

MemTotal 32824336
Active 26197888
UsedFreeMemory 0
AvailableFreeMemory 100

MemTotal=$(awk '/MemTotal:/ {print $2}' /proc/meminfo)
Active=$(awk '/^Active:/ {print $2}' /proc/meminfo)
UsedFreeMemory=$(echo $Active/$MemTotal | bc -l)
AvailableFreeMemory=$(echo 100-$UsedFreeMemory|bc -l)