我喜欢这样的代码:

function getClientIP() {

    if (isset($_SERVER)) {

        if (isset($_SERVER["HTTP_X_FORWARDED_FOR"]))
            return $_SERVER["HTTP_X_FORWARDED_FOR"];

        if (isset($_SERVER["HTTP_CLIENT_IP"]))
            return $_SERVER["HTTP_CLIENT_IP"];

        return $_SERVER["REMOTE_ADDR"];
    }

    if (getenv('HTTP_X_FORWARDED_FOR'))
        return getenv('HTTP_X_FORWARDED_FOR');

    if (getenv('HTTP_CLIENT_IP'))
        return getenv('HTTP_CLIENT_IP');

    return getenv('REMOTE_ADDR');
}

这是我使用的方法，它验证IPv4输入:

// Get user IP address
if ( isset($_SERVER['HTTP_CLIENT_IP']) && ! empty($_SERVER['HTTP_CLIENT_IP'])) {
    $ip = $_SERVER['HTTP_CLIENT_IP'];
} elseif ( isset($_SERVER['HTTP_X_FORWARDED_FOR']) && ! empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
    $ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
} else {
    $ip = (isset($_SERVER['REMOTE_ADDR'])) ? $_SERVER['REMOTE_ADDR'] : '0.0.0.0';
}

$ip = filter_var($ip, FILTER_VALIDATE_IP);
$ip = ($ip === false) ? '0.0.0.0' : $ip;

获取客户端IP地址，请使用getenv("REMOTE_ADDR")。

例如,

$ip_address = getenv("REMOTE_ADDR");
echo $ip_address;

如果你使用localhost调用你的服务器，它会输出::1。 因此，请使用直接服务器ip地址或域名调用您的服务器。

这个函数应该能正常工作

function Get_User_Ip()
{
    $IP = false;
    if (getenv('HTTP_CLIENT_IP'))
    {
        $IP = getenv('HTTP_CLIENT_IP');
    }
    else if(getenv('HTTP_X_FORWARDED_FOR'))
    {
        $IP = getenv('HTTP_X_FORWARDED_FOR');
    }
    else if(getenv('HTTP_X_FORWARDED'))
    {
        $IP = getenv('HTTP_X_FORWARDED');
    }
    else if(getenv('HTTP_FORWARDED_FOR'))
    {
        $IP = getenv('HTTP_FORWARDED_FOR');
    }
    else if(getenv('HTTP_FORWARDED'))
    {
        $IP = getenv('HTTP_FORWARDED');
    }
    else if(getenv('REMOTE_ADDR'))
    {
        $IP = getenv('REMOTE_ADDR');
    }

    //If HTTP_X_FORWARDED_FOR == server ip
    if((($IP) && ($IP == getenv('SERVER_ADDR')) && (getenv('REMOTE_ADDR')) || (!filter_var($IP, FILTER_VALIDATE_IP))))
    {
        $IP = getenv('REMOTE_ADDR');
    }

    if($IP)
    {
        if(!filter_var($IP, FILTER_VALIDATE_IP))
        {
            $IP = false;
        }
    }
    else
    {
        $IP = false;
    }
    return $IP;
}

答案是使用$_SERVER变量。例如，$_SERVER["REMOTE_ADDR"]将返回客户端的IP地址。

我喜欢这样的代码:

function getClientIP() {

    if (isset($_SERVER)) {

        if (isset($_SERVER["HTTP_X_FORWARDED_FOR"]))
            return $_SERVER["HTTP_X_FORWARDED_FOR"];

        if (isset($_SERVER["HTTP_CLIENT_IP"]))
            return $_SERVER["HTTP_CLIENT_IP"];

        return $_SERVER["REMOTE_ADDR"];
    }

    if (getenv('HTTP_X_FORWARDED_FOR'))
        return getenv('HTTP_X_FORWARDED_FOR');

    if (getenv('HTTP_CLIENT_IP'))
        return getenv('HTTP_CLIENT_IP');

    return getenv('REMOTE_ADDR');
}