PHP做下载文件的方法

<?php
header("Content-Type: application/force-download");
header("Content-Disposition: attachment; filename=ins.jpg"); 
readfile("imgs/test_Zoom.jpg");
?>

第一行代码是强制下载；

第二行代码是给下载的内容指定一个名字；

第三行代码是把下载的内容读进文件中。

Example #1 Forcing a download using readfile()

<?php
$file = 'monkey.gif';

if (file_exists($file)) {
    header('Content-Description: File Transfer');
    header('Content-Type: application/octet-stream');
    header('Content-Disposition: attachment; filename='.basename($file));
    header('Content-Transfer-Encoding: binary');
    header('Expires: 0');
    header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
    header('Pragma: public');
    header('Content-Length: ' . filesize($file));
    ob_clean();
    flush();
    readfile($file);
    exit;
}
?>

http://www.php.net/manual/en/function.readfile.php