# untested, but close.
$blocked = Cache::FileCache->new(
  cache_root => '/wherever/blocked_hosts',
  default_expires_in => '30 days',
) or die "no cache!\n";

sub block {   # block($ip,$howlong)
  $blocked->set($_[0], 1, $_[1]);  
}

sub is_blocked {  # is_blocked($ip) -> undef or 1
  $blocked->get($_[0]);
}

sub unblock {  # unblock($ip)
  block($_[0], 'now');  # expire 'now', $ip go poof!
}


block('192.168.254.1');   # 30 days
block('192.168.254.12','6 months');
deny_access if is_blocked('192.168.254.1');
unblock('192.168.254.1');
block('192.168.254.13', 'never');  # block forever!