tp5设置直接下载文件

class Doc
{
public function chandoubasanguo(){
$filename = “static/doc/chandoubasanguo/link.docx”;
$down_host = ${}_{S}ERVER{[}^{\prime }HTT{P}_{H}OS{T}^{\prime }]{.}^{\prime }{/}^{\prime };//当前域名if(fil{e}_{e}xists($_SERVER[‘DOCUMENT_ROOT’].‘/’.KaTeX parse error: Expected '}', got 'EOF' at end of input: …ation:http://'.down_host.$filename);
}
die();
}
}