php文件转换种子文件怎么打开

$announce = "Http://your.tracker.url/announce"; // Tracker URL
$source = "filename.php"; // PHP filename
$name = "filename.mkv"; // File name
$length = filesize($source); // File size
$pieces_length = 1024*1024; // Piece size

$pieces = "";
$sha1_ctx = sha1_init();

$file = fopen($source, "rb");
while (!feof($file)) {
  $data = fread($file, 1024 * 8);
  $sha1_ctx = sha1_update($sha1_ctx, $data);
  $pieces .= sha1($data);  
 }
 fclose($file);

 $hash = sha1_final($sha1_ctx, true);
 $pieces = str_split($pieces, 20);

 $torrent = array(
 'announce' => $announce,
 'info' => array(
        'name' => $name,
        'length' => $length,
        'piece length' => $pieces_length,
        'pieces' => $pieces,
 'sha1' => $hash
 ),
 );

 $torrent_data = bencode($torrent);
 $filename = str_replace(".php", ".torrent", $source);

 $file = fopen($filename, "wb");
 fwrite($file, $torrent_data);
 fclose($file);