#!/bin/bash
while true; do
  entropy=$(cat /proc/sys/kernel/random/entropy_avail)
  echo -n "ENTROPY $(date -Ins) $entropy"
  sleepms=$(echo "$(( $entropy < 100 ? 100 : $entropy )) / 10" | bc -l)
  echo -e " sleeping $sleepms ms"
  sleep $(echo "$sleepms / 1000" | bc -l)
  echo -n "is-system-running: "
  if systemctl is-system-running; then
    echo "REPORT ENTROPY systemd boot finished, quit."
    exit
  fi
done