I needed this code and thought others might too:
Code:
function IsGooglebot(){
// check if user agent contains googlebt
if(eregi("Googlebot",$_SERVER['HTTP_USER_AGENT'])){
$ip = $_SERVER['REMOTE_ADDR'];
//server name e.g. crawl-66-249-66-1.googlebot.com
$name = gethostbyaddr($ip);
//check if name ciontains googlebot
if(eregi("Googlebot",$name)){
//list of IP's
$hosts = gethostbynamel($name);
foreach($hosts as $host){
if ($host == $ip){
return true;
}
}
return false; // Pretender, take some action if needed
}else{
return false; // Pretender, take some action if needed
}
}else{
// Not googlebot, take some action if needed
}
return false;
}