Самый простой способ определения IP-адреса юзера?

<?php
if (isset ($_SERVER['HTTP_X_FORWARDED_FOR']))
{
$host = gethostbyaddr($_SERVER['HTTP_X_FORWARDED_FOR']);
}else{
$host = gethostbyaddr($_SERVER['REMOTE_ADDR']); }

$ip=getenv('REMOTE_ADDR');
$date=date('d M Y, H:i:s');
$host1=gethostbyaddr("$ip");

$str="--Дата - $date|Хост- $host|IP-адрес- $ip\n";
if (!file_exists("report")||filesize("report")==0) {
$fp = fopen("report","w");
fwrite($fp,$str);
fclose($fp);
} else {
$fp = fopen("report","r");
$tmp = explode("\n",fread($fp,filesize("report")));
fclose($fp);
$tmp[] = $str;
$fp = fopen("report","w");
if (count($tmp)>=100) {
$ntmp = array();
$i = count($tmp)-100;
while ($i<count($tmp)) {
$ntmp[] = $tmp[$i];
$i++;
}
fwrite($fp,implode("\n",$ntmp);
} else {
fwrite($fp,implode("\n",$tmp);
}
fclose($fp;
?>