Going through numerous tests, the following results are concluded:
<?
// If you're using a server on Windows, this is faster
function getisp($ip='') {
if ($ip=='') $ip = $_SERVER['REMOTE_ADDR'];
$longisp = @gethostbyaddr($ip);
$isp = explode('.', $longisp);
$isp = array_reverse($isp);
$tmp = $isp[1];
if (preg_match("/\<(org?|com?|net)\>/i", $tmp)) {
$myisp = $isp[2].'.'.$isp[1].'.'.$isp[0];
} else {
$myisp = $isp[1].'.'.$isp[0];
}
if (preg_match("/[0-9]{1,3}\.[0-9]{1,3}/", $myisp))
return 'ISP lookup failed.';
return $myisp;
}
// If your server is on a *nix system, this is faster
function gethost ($ip) {
$host = `host $ip`;
return (($host ? end ( explode (' ', $host)) : $ip));
}
// be warned, however, that gethost() will issue a warning
// if safe mode is on with the use of backticked variables
?>
