#!/bin/bash
RAPL0="/sys/class/powercap/intel-rapl:0/energy_uj"
RAPL1="/sys/class/powercap/intel-rapl:1/energy_uj"
while true; do
    e1=$(( $(cat "$RAPL0") + $(cat "$RAPL1") ))
    sleep 2
    e2=$(( $(cat "$RAPL0") + $(cat "$RAPL1") ))
    echo "scale=1; ($e2 - $e1) / 2000000" | bc > /tmp/power_now
done