$post_data = array () ;
$post_data [ ' clientname ' ] = " test08 " ;
$post_data [ ' clientpasswd ' ] = " test08 " ;
$post_data [ ' submit ' ] = " submit " ;
$url = ' http://xxx.xxx.xxx.xx/xx/xxx/top.php ' ;
$o = "" ;
foreach ( $post_data as $k => $v )
{
     $o .= " $k = " . urlencode ( $v ) . " & " ;
}
$post_data = substr ( $o , 0 ,- 1 ) ;
$ch = curl_init () ;
curl_setopt ( $ch , CURLOPT_POST , 1 ) ;
curl_setopt ( $ch , CURLOPT_HEADER , 0 ) ;
curl_setopt ( $ch , CURLOPT_URL , $url ) ;
//为了支持cookie
curl_setopt ( $ch , CURLOPT_COOKIEJAR , ' cookie.txt ' ) ;
curl_setopt ( $ch , CURLOPT_POSTFIELDS , $post_data ) ;
$result = curl_exec ( $ch ) ;

2. 通过fsockopen
$URL =‘ http : //xxx.xxx.xxx.xx/xx/xxx/top.php';
$post_data [ ' clientname ' ] = " test08 " ;
$post_data [ ' clientpasswd ' ] = " test08 " ;
$post_data [ ' submit ' ] = " ログイン " ;
$referrer = "" ;
// parsing the given URL
$URL_Info = parse_url ( $URL ) ;
// Building referrer
if ( $referrer == "" ) // if not given use this script as referrer
$referrer = $_SERVER [ " SCRIPT_URI " ] ;
 
// making string from $data
foreach ( $post_data as $key => $value )
$values [] = " $key = " . urlencode ( $value ) ;
 
$data_string = implode ( " & " , $values ) ;
// Find out which port is needed - if not given use standard (=80)
if ( ! isset ( $URL_Info [ " port " ]))
$URL_Info [ " port " ] = 80 ;
// building POST-request:
$request .= " POST " . $URL_Info [ " path " ] . " HTTP/1.1 \n " ;
$request .= " Host: " . $URL_Info [ " host " ] . " \n " ;
$request .= " Referer: $referrer \n " ;
$request .= " Content-type: application/x-www-form-urlencoded \n " ;
$request .= " Content-length: " . strlen ( $data_string ) . " \n " ;
$request .= " Connection: close \n " ;
$request .= " \n " ;
$request .= $data_string . " \n " ;
$fp = fsockopen ( $URL_Info [ " host " ] , $URL_Info [ " port " ]) ;
fputs ( $fp , $request ) ;
while ( ! feof ( $fp )) {
     $result .= fgets ( $fp , 128 ) ;
}
fclose ( $fp ) ;

上述两种方法没有封装成通用的function，我验证了方法2，发现基本上能实现功能，但有两个很大的缺点：
1. 延迟比较大，我在内网测试，用命令行进行的测试，发现响应有时候需要2S以上，不能接受。
2. 读到的response包含了HTTP头域信息，但是大部分情况下，我们只需要body部分内容，要提取body内容，还需要一番处理。
方法1感觉也很笨拙，似乎也很难满足我的需求，最后忘记在哪个英文网站上找到了下面这个方法：
  function do_post_request($url, $data, $optional_headers = null)
  {
     $params = array('http' => array(
                  'method' => 'POST',
                  'content' => $data
               ));
     if ($optional_headers !== null) {
        $params['http']['header'] = $optional_headers;
     }
     $ctx = stream_context_create($params);
     $fp = @fopen($url, 'rb', false, $ctx);
     if (!$fp) {
        throw new Exception("Problem with $url, $php_errormsg");
     }
     $response = @stream_get_contents($fp);
     if ($response === false) {
        throw new Exception("Problem reading data from $url, $php_errormsg");
     }
     return $response;
  }

本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/xingtian713/archive/2009/09/08/4533491.aspx