php 获取用户登录的ip

/** get_ip()获取真实IP函数
* @param integer $type 返回类型 0 返回IP地址 1 返回IPV4地址数字
* @return string
*/
function get_true_ip($type=0){
$type = $type ? 1:0;
static $ip = null;
if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown"))
$ip = getenv("HTTP_CLIENT_IP");
else if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown"))
$ip = getenv("HTTP_X_FORWARDED_FOR");
else if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown"))
$ip = getenv("REMOTE_ADDR");
else if (isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown"))
$ip = $_SERVER['REMOTE_ADDR'];
else
$ip = "unknown";
$long = sprintf("%u",ip2long($ip));
$ip = $long ? array($ip, $long) : array('0.0.0.0', 0);
return $ip[$type];
}