<?php
function readIP($path, $file, $ip) {
    $flag = false;
    if(file_exists($path.$file)) {
        if ($data = fopen($path.$file, "r")) {
            while(!feof($data)) {
                $line = fgets($data);
                if($line != '') {
                    $line = explode("-", $line);
                    if(trim($ip) == trim($line[2])) {
                        $flag = true;
                    }
                }
            }
            fclose($data);
        }
    }
    return $flag;
}
function writeIP($path, $file, $ip) {
    $ip = date("d.m.Y - H:i:s "). " - ".$ip;
    if(file_exists($path.$file)) {
        $fo = fopen($path.$file, "a");
        fwrite($fo, $ip."\n");
        fclose($fo);
    }
}

$filePath = "./";
$fileName = "ip.txt";

$ip = $_SERVER['REMOTE_ADDR'];

if (readIP($filePath, $fileName, $ip) === false) {
    writeIP($filePath, $fileName, $ip);
}
header( 'Location: https://wunschdomain.com') ;
?>