# http文件下载与404
if (!file_exists($file_path)) { header('HTTP/1.1 404 Not Found'); header("status: 404 Not Found"); http_response_code(404); exit(404); }
header( 'Content-Disposition: attachment; filename='.basename($file_path)); header('Content-Length: ' . filesize($file_path)); ob_clean(); flush(); readfile($file_path);