Download File

<?php

if ( ! defined( 'ABSPATH' ) ) exit; // Exit if accessed directly

// $file = sanitize_file_name( $_GET['path'] );
// sanitize path
$file = realpath( $_GET['path'] );
// echo $file;
if ( current_user_can( 'edit_shop_orders' ) && check_admin_referer( 'download-dhl-label' ) ) {

	if( file_exists($file) ) {
		// echo 'file exists';
		// echo '<br/>';
		// echo $file;
		$file_info = pathinfo($file);
		$ext = strtoupper($file_info['extension']);
		// echo $ext['extension'];
		// echo $ext;
		$allowed_ext = array( 'PDF', 'PNG', 'ZPL' );

		if( in_array($ext, $allowed_ext) ) {
			// echo 'allowd';
		    header('Content-Description: File Transfer');
		    header('Content-Type: application/octet-stream');
		    header('Content-Disposition: attachment; filename="'.basename($file).'"');
		    header('Expires: 0');
		    header('Cache-Control: must-revalidate');
		    header('Pragma: public');
		    header('Content-Length: ' . filesize($file));
		    readfile($file);
		    exit;
		}
	}
}
?>