获取“包含文件执行结果”的字符串

<div id='top'>    <?php $user="张三"; ?>    <p>欢迎你：<?php print $user ?> <a href='../public/logout.php'>注销</a></p></div>

<?php$s=file_get_contents('a.php',1);?>

<div id='top'>    <p>欢迎你：张三 <a href='../public/logout.php'>注销</a></p>
                    <div class="aritcle_card">
                        <a class="aritcle_card_img" href="/ai/2045">
                            <img src="https://img.php.cn/upload/ai_manual/001/246/273/68b6cc4ba7841777.png" alt="TTS Free Online免费文本转语音">
                        </a>
                        <div class="aritcle_card_info">
                            <a href="/ai/2045">TTS Free Online免费文本转语音</a>
                            <p>免费的文字生成语音网站，包含各种方言（东北话、陕西话、粤语、闽南语）</p>
                            <div class="">
                                <img src="/static/images/card_xiazai.png" alt="TTS Free Online免费文本转语音">
                                <span>37</span>
                            </div>
                        </div>
                        <a href="/ai/2045" class="aritcle_card_btn">
                            <span>查看详情</span>
                            <img src="/static/images/cardxiayige-3.png" alt="TTS Free Online免费文本转语音">
                        </a>
                    </div>
                </div>

ob_start();include 'a.php';$s = ob_get_clean);

ob_start();include 'a.php';$s = ob_get_clean();