在許多時候，我們會不希望網友知道網址空間直接下載檔案，或是透過帳號密碼的管控才能下載時，該如何用程式做過濾及管制呢？
header("Content-type:application");
header("Content-Disposition: attachment; filename=file_name");
//file_name是預設下載時的檔名，可使用變數。
readfile("file");
//file是實際存放在你硬碟中要被下載的檔案，可使用變數。
exit(0);
header('Content-Type: application/pdf');
header('Content-Disposition: attachment; filename="downloaded.pdf"');
readfile('original.pdf');
//限制下載速度，使用 while 迴圈加上 sleep。
while (!feof($handle)) {
echo fread($handle, 8192);
sleep(1);
}
$content = "";
$fp = fopen("http://file-to-download.com/a-file.zip", "rb");
if (!$fp)
die("Error opening file.");
while (!feof($fp))
$content .= fread($fp, 2048);
fclose($fp);
$fp=fopen("local-file-name.zip", "w");
fwrite($fp, $content);
fclose($fp);
$OrgFileName = mb_convert_encoding($OrgFileName, 'BIG-5','UTF-8');
$real_path = dirname(__FILE__).'/upload/'.$FileName;
header('Pragma: public');
header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Cache-Control: public', false);
header('Content-Description: File Transfer');
header('Accept-Ranges: bytes');
// application/force-download 為通用類型，亦可判斷檔案格式做改變
header('Content-Type: application/force-download');
header('Content-Length: '.filesize($real_path));
header('Content-Transfer-Encoding: binary');
// 注意「"」不可省略，否則FireFox會無法正確讀取
header('Content-Disposition:attachment;filename="'.$OrgFileName.'"');
// 讀取來源檔案資料
if ($stream = fopen($real_path, 'rb')){
while(!feof($stream) && connection_status() == 0){
echo(fread($stream,1024*8));
flush();
}
fclose($stream);
}
header('Content-type:application/force-download'); //告訴瀏覽器 為下載
header('Content-Transfer-Encoding: Binary'); //編碼方式
header('Content-Disposition:attachment;filename='.$filename); //檔名
@readfile($filename);
