location /download {
alias /download;
if ($request_uri ~* ^.*\/(.*)\.(docx|DOCX|pptx|PPTX|xlsx|XLSX|doc|DOC|ppt|PPT|xls|XLS|wps|et|dps|jpg|JPG|jpeg|JPEG|png|PNG|gif|GIF|bmp|BMP|emf|EMF|wmf|WMF|tif|TIF|tiff|TIFF|wdp|WDP|jpe|JPE|zip|ZIP)(\?n=([^&]+))$) {
add_header Content-Disposition "attachment;filename=$arg_n";
}
#autoindex on;
}