php不透露实际地址的文件下载
function download_document($filename, $path = "", $mimetype = "application/octet-stream")
{
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Content-Disposition: attachment; filename = $filename");
header("Content-Length: " . filesize($pathto . $filename));
header("Content-Type: $mimetype");
echo file_get_contents($pathto . $filename);
}
