#!/usr/bin/perl
use strict;
use warnings;

my $stash = '/tmp/cookie.tmp';
my $reps = 0;

getCookie($stash);
setCookie($reps);

sub getCookie {
  my $s=shift;
  chomp $s;

  if ( open my $IN, '<', $s ) {
    while (<$IN>) {
      $reps = $_;
      chomp $reps;
      next unless $reps =~/^\d+$/;
    }
    close $IN;
  }
}

sub setCookie {
  my $r=shift;
  die $r unless $r=~/^\d+$/;
  open my $O, '>', $stash;
  printf $O "%s\n", $r;
  close $O;
}