my $exp = Expect->spawn("telnet localhost")
    or die "Cannot spawn telnet: $!\n";;
  my $spawn_ok;
  $exp->expect($timeout,
               [
                qr'login: $',
                sub {
                  $spawn_ok = 1;
                  my $fh = shift;
                  $fh->send("$username\n");
                  exp_continue;
                }
               ],
               [
                'Password: $',
                sub {
                  my $fh = shift;
                  print $fh "$password\n";
                  exp_continue;
                }
               ],
               [
                eof =>
                sub {
                  if ($spawn_ok) {
                    die "ERROR: premature EOF in login.\n";
                  } else {
                    die "ERROR: could not spawn telnet.\n";
                  }
                }
               ],
               [
                timeout =>
                sub {
                  die "No login.\n";
                }
               ],
               '-re', qr'[#>:] $', #' wait for shell prompt, then exit expect
              );