探討file_get_contents與curl效率及穩定性的分析

做過好多抓取別家網站內容的產品，習慣了使用方便快捷的file_get_contents函數，但是總是會遇到獲取失敗的問題，盡管按照手冊中的例子設置了超時，可多數時候不會奏效：
復制代碼 代碼如下:
$config['context'] = stream_context_create(array(‘http' => array(‘method' => “GET”,
   'timeout' => 5//這個超時時間不穩定，經常不奏效
   )
  ));

這時候，看一下服務器的連接池，會發現一堆類似的錯誤，讓你頭疼萬分：
file_get_contents(http://***): failed to open stream…
不得已，安裝了curl庫，寫了一個函數替換：
復制代碼 代碼如下:
<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>
   <span style="color:#000088">$r</span> <span style="color:#339933">=</span> <span style="color:#990000">curl_exec</span><span style="color:#009900">(</span><span style="color:#000088">$ch</span><span style="color:#009900">)</span><span style="color:#339933">;</span>
   <span style="color:#990000">curl_close</span><span style="color:#009900">(</span><span style="color:#000088">$ch</span><span style="color:#009900">)</span><span style="color:#339933">;</span>
   <span style="color:#b1b100">return</span> <span style="color:#000088">$r</span><span style="color:#339933">;</span>
 <span style="color:#009900">}</span>

如此，除了真正的網絡問題外，沒再出現任何問題。
這是別人做過的關於curl和file_get_contents的測試：
file_get_contents抓取google.com需用秒數：
2.31319094
2.30374217
2.21512604
3.30553889
2.30124092
curl使用的時間：
0.68719101
0.64675593
0.64326
0.81983113
0.63956594
差距很大吧？呵呵，從我使用的經驗來說，這兩個工具不只是速度有差異，穩定性也相差很大。建議對網絡數據抓取穩定性要求比較高的朋友使用上面的curl_file_get_contents函數，不但穩定速度快，還能假冒浏覽器欺騙目標地址哦！