php下获取客户端ip地址的函数_php技巧

function getip() {
$IP=getenv('REMOTE_ADDR');
$IP_ = getenv('HTTP_X_FORWARDED_FOR');
if (($IP_ != "") && ($IP_ != "unknown")) $IP=$IP_;
return $IP;
}

下面这个比较好的

function getIP()
{
if (isset($_SERVER)) {
if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
$realip = $_SERVER['HTTP_X_FORWARDED_FOR'];
} elseif (isset($_SERVER['HTTP_CLIENT_IP'])) {
$realip = $_SERVER['HTTP_CLIENT_IP'];
} else {
$realip = $_SERVER['REMOTE_ADDR'];
}
} 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");
}
}
return $realip;
}