1.通过curl函数

$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);

Snoopy 类（2）
sourceforge.net/projects/snoopy/
http://www.redalt.com/xref/trunk/nav.htm?wp-includes/class-snoopy.php.htm
HTTP类（1，2）
http://www.phpclasses.org/browse/download/1/file/5/name/http.php
PEAR HTTP_Request
http://pear.php.net/package/HTTP_Request