强制PHP通过浏览器下载文件

<?php
$file = 'path/to/file'; // 文件路径

// 设置HTTP头部信息
header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename=' . basename($file));
header('Content-Transfer-Encoding: binary');
header('Expires: 0');
header('Cache-Control: must-revalidate');
header('Pragma: public');
header('Content-Length: ' . filesize($file));

// 读取文件并输出到浏览器
readfile($file);
?>