php获取客服端ip

/**
* 获取客户端IP地址
* @param integer $type 返回类型 0 返回IP地址 1 返回IPV4地址数字
* @return mixed
*/
function get_client_ip($type = 0) {
$type       =  $type ? 1 : 0;
static $ip  =   NULL;
if ($ip !== NULL) return $ip[$type];
if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
$arr    =   explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
$pos    =   array_search('unknown',$arr);
if(false !== $pos) unset($arr[$pos]);
$ip     =   trim($arr[0]);
}elseif (isset($_SERVER['HTTP_CLIENT_IP'])) {
$ip     =   $_SERVER['HTTP_CLIENT_IP'];
}elseif (isset($_SERVER['REMOTE_ADDR'])) {
$ip     =   $_SERVER['REMOTE_ADDR'];
}
// IP地址合法验证
$long = sprintf("%u",ip2long($ip));
$ip   = $long ? array($ip, $long) : array('0.0.0.0', 0);
return $ip[$type];
}