Reverse ajax, comet, server push

<code><span><span><?php</span>
set_time_limit(<span>0</span>);
ob_start();
<span>$str</span>=str_repeat(<span>' '</span>,<span>4000</span>);
<span>echo</span><span>$str</span>;
ob_flush(); <span>//把产生的内容，立即送给浏览器而不要等脚本结束后再一起送</span>
flush();
<span>$i</span>=<span>1</span>;
<span>while</span>(<span>$i</span>++) {
    <span>echo</span><span>$str</span>,<span>'<br/>'</span>;
    <span>echo</span><span>$i</span>,<span>'<br/>'</span>;
    ob_flush();
    flush();    <span>//把产生的内容，立即送给浏览器而不要等脚本结束后再一起送</span>
    sleep(<span>1</span>);
}

<span>/*
思考：如果while循环中，不是1，2，3...
而是数据库中的内容呢？
而是2人的聊天记录呢？
这样就能达到，即时通信

服务器端----不间断---推送信息---->客户端
*/</span></span></code>

The above has introduced reverse ajax, comet, and server push, including the relevant content. I hope it will be helpful to friends who are interested in PHP tutorials.