我正在尝试用 php 写入文件并下载它。总是第一行出现空白,这是错误的

I am trying write file with php and download it. Always first line appears in blank and that is wrong

我正在生成一个类似于 xml 的文件。

当我拥有所有字符串时,我会尝试即时编写和下载它。

当我打开文件时问题就开始了:第一行是空白,纯文本从第二行开始。我已经用 fwrite、fput 和 file_put_contents() 进行了测试……但是……

我一直没能解决问题...

这是一段代码:

function dw($str, $name){
        $handle = fopen($name.'.fmt', "w");
        fwrite($handle, utf8_encode($str));
        fclose($handle);
        header('Content-Type: text/xml');
        header('Content-Disposition: attachment; filename='.basename($name.'.fmt'));
        header('Expires: 0');
        header('Cache-Control: must-revalidate');
        header('Pragma: public');
        header('Content-Length: ' . filesize($name.'.fmt'));
        readfile($name.'.fmt');
        exit;
}

我找到了解决方案(也许有人需要这个答案):

    $handle = fopen($name.'.fmt', "wb");
    rewind($handle);
    fwrite($handle, $new_dom->saveXML());
    fclose($handle);

    header('Content-Description: File Transfer');
    header('Content-Type: text/xml');
    header('Content-Disposition: attachment; filename=' . basename($name.'.fmt'));
    header('Expires: 0');
    header('Cache-Control: must-revalidate');
    header('Pragma: public');
    header('Content-Length: ' . filesize($name.'.fmt'));
    ob_clean();
    readfile($name.'.fmt');