php用header()实现文件下载功能

<p>function download($file_url,$new_name=''){</p>
                    <div class="aritcle_card">
                        <a class="aritcle_card_img" href="/ai/950">
                            <img src="https://img.php.cn/upload/ai_manual/000/000/000/175680003823895.png" alt="ViiTor实时翻译">
                        </a>
                        <div class="aritcle_card_info">
                            <a href="/ai/950">ViiTor实时翻译</a>
                            <p>AI实时多语言翻译专家！强大的语音识别、AR翻译功能。</p>
                            <div class="">
                                <img src="/static/images/card_xiazai.png" alt="ViiTor实时翻译">
                                <span>116</span>
                            </div>
                        </div>
                        <a href="/ai/950" class="aritcle_card_btn">
                            <span>查看详情</span>
                            <img src="/static/images/cardxiayige-3.png" alt="ViiTor实时翻译">
                        </a>
                    </div>
                	if(!isset($file_url)||trim($file_url)==''){<br />		return '500';<br />	}<br />	if(!file_exists($file_url)){//检查文件是否存在<br />		return '404';<br />	}<br />	$file_name=basename($file_url);<br />	$file_type=explode('.',$file_url);<br />	$file_type=$file_type[count($file_type)-1];<br />	$file_name=trim($new_name=='')?$file_name:urlencode($new_name).'.'.$file_type;<br />	//输入文件标签phpernote<br />	header("Content-type: application/octet-stream");<br />	header("Accept-Ranges: bytes");<br />	header("Accept-Length: ".filesize($file_url));<br />	header("Content-Disposition: attachment; filename=".$file_name);<br />	//输出文件内容<br />	@readfile($file_type);<br />}