php 获取远程内容，能否只建立一次连接，多次使用.解决方法

[User:root Time:14:07:31 Path:/home/liangdong/php]$ php file.php HTTP/1.1 200 OKDate: Thu, 10 May 2012 18:07:32 GMTServer: Apache/2.4.1 (Unix) PHP/5.4.0X-Powered-By: PHP/5.4.0Set-Cookie: PHPSESSID=qi60b6s1q783a4pnj81rscdet4; path=/Expires: Thu, 19 Nov 1981 08:52:00 GMTCache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0Pragma: no-cacheContent-Length: 257Keep-Alive: timeout=5, max=100Connection: Keep-AliveContent-Type: text/html; charset=utf-8<div style="font-weight:normal;color:blue;float:left;width:345px;text-align:center;border:1px solid silver;background:#E8EFFF;padding:8px;font-size:14px;font-family:Tahoma">^_^ Hello,欢迎使用<span style="font-weight:bold;color:red">ThinkPHP</span>
</div>GET / HTTP/1.1Host: localhostAccept: */*Connection:Keep-alive[User:root Time:14:07:32 Path:/home/liangdong/php]$ cat file.php <?php $curl = curl_init();curl_setopt($curl, CURLOPT_URL, 'http://localhost');curl_setopt($curl, CURLOPT_FORBID_REUSE, false);curl_setopt($curl, CURLOPT_FRESH_CONNECT, false);curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);curl_setopt($curl, CURLOPT_HEADER, true);curl_setopt($curl, CURLINFO_HEADER_OUT, true);curl_setopt($curl, CURLOPT_HTTPHEADER, array('Connection:Keep-alive'));$res = curl_exec($curl);if ($res !== false) {        echo $res . PHP_EOL;        $req = curl_getinfo($curl, CURLINFO_HEADER_OUT);        print_r($req);}?>[User:root Time:14:07:43 Path:/home/liangdong/php]$<div class="clear"></div>