opendir(DIR, $path) or die("No opendir on $path\n");
while (defined($_ = readdir DIR)) {
  if (/^${id}\_.*$/o) {
    $filename = "$path/$_";
    last;
  }
}
closedir(DIR);
if ($filename) {
  unlink($filename) or die("No unlink on $filename\n");
}