use Expect;
my $timeout=5;

foreach my $i (1..20)
{
  my $exp = Expect->spawn("./unreliable.pl")
    or die "Cannot spawn unreliable process $!\n";

  $exp->expect($timeout,
    [
      timeout =>
        sub
        {
          print "Process timed out.\n";
        }
    ]
  );
}