PHP获取真实的IP地址

 function GetIP()

{

static $realip = NULL;

if ($realip !== NULL)

{

return $realip;

}

if (isset($_SERVER))

{

if (isset($_SERVER['HTTP_X_FORWARDED_FOR']))

{

$arr = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);

foreach ($arr as $ip)

{

$ip = trim($ip);

if ($ip != 'unknown')

{

$realip = $ip;

break;

}

}

}

elseif (isset($_SERVER['HTTP_CLIENT_IP']))

{

$realip = $_SERVER['HTTP_CLIENT_IP'];

}

else

{

if (isset($_SERVER['REMOTE_ADDR']))

{

$realip = $_SERVER['REMOTE_ADDR'];

}

else

{

$realip = '127.0.0.1';

}

}

}

else

{

if (getenv('HTTP_X_FORWARDED_FOR'))

{

$realip = getenv('HTTP_X_FORWARDED_FOR');

}

elseif (getenv('HTTP_CLIENT_IP'))

{

$realip = getenv('HTTP_CLIENT_IP');

}

else

{

$realip = getenv('REMOTE_ADDR');

}

}

preg_match("/[\d\.]{7,15}/", $realip, $onlineip);

$realip = ! empty($onlineip[0]) ? $onlineip[0] : '127.0.0.1';

return $realip;

}