通過php下載檔案並重新命名

$filename = dirname(__FILE__) . `/oldfilename.jpg`;
$out_filename = `newfilename.jpg`;
if( ! file_exists($filename)){
　　echo `Not Found` . $filename;
　　exit;
} else {
　　// We`ll be outputting a file
　　header(`Accept-Ranges: bytes`);
　　header(`Accept-Length: ` . filesize($filename));
　　// It will be called
　　header(`Content-Transfer-Encoding: binary`);
　　header(`Content-type: application/octet-stream`);
　　header(`Content-Disposition: attachment; filename=` . $out_filename);
　　header(`Content-Type: application/octet-stream; name=` . $out_filename);
　　// The source is in filename
if(is_file($filename) && is_readable($filename)){
　　　　$file = fopen($filename, “r”);
　　　　echo fread($file, filesize($filename));
　　　　fclose($file);
}
　　exit;
}