How can PHP developers ensure a smooth and uninterrupted file download process when accessing files from a remote domain?

When accessing files from a remote domain in PHP, developers can ensure a smooth and uninterrupted file download process by using the `readfile()` function along with setting appropriate headers to handle the file transfer correctly. This approach ensures that the file is streamed directly to the client without loading it into memory entirely, which can prevent timeouts and memory issues during the download process.

<?php
$file_url = 'http://www.example.com/file.zip';
$file_name = basename($file_url);

header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename="' . $file_name . '"');
header('Expires: 0');
header('Cache-Control: must-revalidate');
header('Pragma: public');
header('Content-Length: ' . filesize($file_url));

readfile($file_url);
exit;
?>