Nah, the best way is to made graal call a PHP file through graal using requesturl
PHP Code:
function onActionPlayeronline() {
requesturl("http://location/to/php.file?online=1&account=" @ player.account);
}
Then, in the php file have it store the online players to either a text file or a database, make a new request when the player goes offline to remove the player from the list.