my $subr = $r->lookup_file($file);
  return 404 unless -f $file and $subr->status == 200;
  $r->content_type("application/download");
  $r->header_out('Content-disposition' => "attachment; filename=\"$file\"");
  $r->send_http_header;
  return 200 if $r->header_only;
  $subr->run;
  $m->abort;