php实现文件强制下载代码

/**
* php强制下载文件
* edit: bbs.it-home.org
*/
$file_dir = "./";
$name = "test.txt";
$file = fopen($file_dir.$name,"r");
Header("Content-type: application/octet-stream");
Header("Accept-Ranges: bytes");
Header("Accept-Length: ".filesize($file_dir . $name));
Header("Content-Disposition: attachment; filename=".$name);
echo fread($file, filesize($file_dir.$name));
fclose($file);
?>

代码很简单，主要学习下php强制下载文件的原理与实现方法，大家可以在此基础上完善。