#!/usr/bin/perl
$|++;
my $last;
my $file = shift || "/proc/sys/kernel/random/entropy_avail";
my $sleep_time = shift || 0.1;
open ENT, "<", $file;
while (<ENT>) {
  chomp;
  print "
$_" . (" " x (length($last) - length $_)) unless $_ eq $last;
  $last = $_;
  sleep $sleep_time;
  seek ENT, 0, 0;
}