Salvare $buffer in un file mp3

[Ranma2]

Ho trovato il seguente script dovrebbe fungere da SHOUTcast PROXY

<?php
echo $tenPercentOfFileInBytes;
$streamToOpen = "***.***.***.***";
$port = "8000";
$path = "/";
header("Content-type: audio/mpeg");
$socket = fsockopen($streamToOpen,$port);
fputs($socket, "GET $path HTTP/1.0\r\n");
fputs($socket, "Host: $streamToOpen\r\n");
fputs($socket, "User-Agent: SHOUTcast PROXY/1.0\r\n");
fputs($socket, "Accept: */*\r\n");
fputs($socket, "Connection: close\r\n\r\n");
    while (!feof($socket)) {
        $buffer = fgets($socket, 4096);
        echo $buffer;
    }
$totalSize = 0;
    for ($i=0; $i < $tenPercentOfFileInBytes; ) {
        $buffer = fgets($socket);
        $strSize = strlen($buffer);
        $totalSize = $totalSize + $strSize;
        echo "$strSize \n";
        $i = $i + $strSize;
        echo $buffer;

    }
fclose($socket);
?>

vorrei salvare $buffer dentro ad un file mp3, fino ad una certa dimensione, e poi eliminare le parti ricevute più vecchie per aggiungere le nuove