too long

i wrote a download script that find a restricted file from server and after reading that, prepare the file for user to download it with the following headers.

header('Content-Type: application/octet-stream');
header("Content-Length: $filesize");
header('Content-Disposition: attachment; filename="'.basename($file).'"');
header('Accept-Ranges: bytes');
header('Connection: Keep-Alive');
header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Pragma: public');

but sometimes with default browsers download managers, it returns download-file.php instead of filename!

for example it should return abc.zip but it returns download-file.php and download process works perfectly

any help will be appreciated

Since I don't know how you're using $file or $filesize try this instead:

$file = "abc.zip"; // adjust accordingly
header("Pragma: public");
header("Expires: 0");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Content-Type: application/force-download");
header("Content-Disposition: attachment; filename=".basename($file));
header("Content-Transfer-Encoding: binary");
header("Content-Length: ".filesize($file));
header("Content-Description: File Transfer");
@readfile($file);
exit();

plus, a missing readfile()

This line:

header("Content-Length: $filesize");

should read as:

header("Content-Length: ".filesize($file)); // or $filesize in your case.

Missing filesize()