探讨file_get_contents与curl效率及稳定性的分析

做过好多抓取别家网站内容的产品，习惯了使用方便快捷的file_get_contents函数，但是总是会遇到获取失败的问题，尽管按照手册中的例子设置了超时，可多数时候不会奏效：
代码如下:
$config['context'] = stream_context_create(array(‘http' => array(‘method' => “GET”,
   'timeout' => 5//这个超时时间不稳定，经常不奏效
   )
  ));

这时候，看一下服务器的连接池，会发现一堆类似的错误，让你头疼万分：
file_get_contents(http://***): failed to open stream…
不得已，安装了curl库，写了一个函数替换：
代码如下:
<span style="color:#000000; font-weight:bold">function</span> curl_file_get_contents<span style="color:#009900">(</span><span style="color:#000088">$durl</span><span style="color:#009900">)</span><span style="color:#009900">{</span>
   <span style="color:#000088">$ch</span> <span style="color:#339933">=</span> <span style="color:#990000">curl_init</span><span style="color:#009900">(</span><span style="color:#009900">)</span><span style="color:#339933">;</span>
   <span style="color:#990000">curl_setopt</span><span style="color:#009900">(</span><span style="color:#000088">$ch</span><span style="color:#339933">,</span> CURLOPT_URL<span style="color:#339933">,</span> <span style="color:#000088">$durl</span><span style="color:#009900">)</span><span style="color:#339933">;</span>
   <span style="color:#990000">curl_setopt</span><span style="color:#009900">(</span><span style="color:#000088">$ch</span><span style="color:#339933">,</span> CURLOPT_TIMEOUT<span style="color:#339933">,</span> <span style="color:#cc66cc">5</span><span style="color:#009900">)</span><span style="color:#339933">;</span>
   <span style="color:#990000">curl_setopt</span><span style="color:#009900">(</span><span style="color:#000088">$ch</span><span style="color:#339933">,</span> CURLOPT_USERAGENT<span style="color:#339933">,</span> _USERAGENT_<span style="color:#009900">)</span><span style="color:#339933">;</span>
   <span style="color:#990000">curl_setopt</span><span style="color:#009900">(</span><span style="color:#000088">$ch</span><span style="color:#339933">,</span> CURLOPT_REFERER<span style="color:#339933">,</span>_REFERER_<span style="color:#009900">)</span><span style="color:#339933">;</span>
   <span style="color:#990000">curl_setopt</span><span style="color:#009900">(</span><span style="color:#000088">$ch</span><span style="color:#339933">,</span> CURLOPT_RETURNTRANSFER<span style="color:#339933">,</span> <span style="color:#cc66cc">1</span><span style="color:#009900">)</span><span style="color:#339933">;</span>