<?
$download_dir="../../upload/";
$fp = fopen($upload_dir.$download_file,"r"); // 打开文件 
// 输入文件标签
Header("Content-type: application/octet-stream");
Header("Accept-Ranges: bytes");
Header("Accept-Length: ".filesize($upload_dir.$download_file));
Header("Content-Disposition: attachment; filename=" . $download_file);
// 输出文件内容
echo fread($fp,filesize($download_dir . $download_file));
fclose($fp);
?>