What are the best practices for downloading multiple files using PHP without causing conflicts or errors?

When downloading multiple files using PHP, it is important to ensure that each file is downloaded sequentially to avoid conflicts or errors. One way to achieve this is by using a loop to iterate through the list of files and download them one by one.

<?php

$files = array("file1.pdf", "file2.jpg", "file3.txt");

foreach ($files as $file) {
    $file_path = "path/to/files/" . $file;
    
    if (file_exists($file_path)) {
        header('Content-Description: File Transfer');
        header('Content-Type: application/octet-stream');
        header('Content-Disposition: attachment; filename="' . basename($file_path) . '"');
        header('Expires: 0');
        header('Cache-Control: must-revalidate');
        header('Pragma: public');
        header('Content-Length: ' . filesize($file_path));
        readfile($file_path);
    } else {
        echo "File not found: " . $file;
    }
}

?>