Curl 采集乱码与采集不到 PHP,该怎么处理

Curl 采集乱码与采集不到 PHP
PHP程序是用gbk2312编码的：

$url = "http://www.sina.com.cn";//gbk2312编码
//$url = "http://www.163.com";//gbk2312编码
//$url = "http://www.sohu.com";//gbk2312编码
 

  $ch = curl_init($url);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER , true);//返回获取的输出的文本流
  $ret = curl_exec($ch);
  curl_setopt($ch, CURLOPT_TIMEOUT, 1);
  curl_close($ch);
  echo $ret;

?>

在采集sina.com.cn时，是正常的，但是采集163.com时是为空的，采集sohu.com时是丢码的.
这是怎么回事呢？如何解决？有哪位怎么呀？先谢谢了！！！没多少分了，不好意思。

------解决方案--------------------
别的不说,我就是来拿分的.楼主记得给全分

PHP code

$curl=curl_init('http://www.163.com');curl_setopt($curl,CURLOPT_RETURNTRANSFER,1);curl_setopt($curl,CURLOPT_USERAGENT,'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322)');$html=curl_exec($curl);var_dump($html);$curl=curl_init('http://www.sohu.com');curl_setopt($curl,CURLOPT_RETURNTRANSFER,1);curl_setopt($curl,CURLOPT_USERAGENT,'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322)');$html=curl_exec($curl);//$html=strstr($html,' 0) {      switch ($method) {        case 8:          // Currently the only supported compression method:          $data = gzinflate($body);          break;        default:          // Unknown compression method          return false;      }     } else {      // I'm not sure if zero-byte body content is allowed.      // Allow it for now...  Do nothing...     }       // Verifiy decompressed size and CRC32:     // NOTE: This may fail with large data sizes depending on how     //      PHP's integer limitations affect strlen() since $isize     //      may be negative for large sizes.     if ($isize != strlen($data) || crc32($data) != $datacrc) {      // Bad format!  Length or CRC doesn't match!      return false;     }     return $data;   }<div class="clear">
                 
              
              
        
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