my $line;
eval {
  local $SIG{ALRM} = sub { die "alarm clock restart" };
  alarm 10;
  $line = <$child>;
  alarm 0;
};
if ($@) {
  if ($@ =~ /alarm clock restart/) {
    print "$$ alarm triggered\n";
    next;
  } else {
    die "$$ Other error $@\n";
  }
}