获得访问者的ip

function getip() {
if (isSet($_SERVER)) {
if (isSet($_SERVER["HTTP_X_FORWARDED_FOR"])) {
$realip = $_SERVER["HTTP_X_FORWARDED_FOR"];
} elseif (isSet($_SERVER["HTTP_CLIENT_ip"])) {
$realip = $_SERVER["HTTP_CLIENT_ip"];
} else {
$realip = $_SERVER["REMOTE_ADDR"];
}
} else {
if ( getenv( 'HTTP_X_FORWARDED_FOR' ) ) {
$realip = getenv( 'HTTP_X_FORWARDED_FOR' );
} elseif ( getenv( 'HTTP_CLIENT_ip' ) ) {
$realip = getenv( 'HTTP_CLIENT_ip' );
} else {
$realip = getenv( 'REMOTE_ADDR' );
}
}
return $realip;
}