for my $file_k0 ( sort keys %h ) {
    for my $file_k1 ( sort keys %{ $h{$file_k0} } ) {
      print "File $file_k0.$file_k1 -\n";
      for my $line_ar ( @{ $h{$file_k0}{$file_k1} } ) {
        for my $field ( @$line_ar ) {
          print "\t$field";
        }
        print "\n";
      }
    }
  }