How do I check if a user is authenticated with NickServ using POE::Component::IRC::State in Perl?

I'm trying to test whether a user is registered on FreeNode. nick_info() doesn't seem to return information about this, so I want to use $irc->yield(whois => $nick); and then grab the irc_whois event's reply. The problem is that I want to wait until this event is fired, so I created a global variable $whois_result and wrote a sub like this:

sub whois {
    my $nick = $_[0];
    $whois_result = 0;
    $irc->yield(whois => $nick);
    while($whois_result == 0) { }
    return $whois_result;
}

with the irc_whois handler looking like:

sub on_whois {
    $whois_result = $_[ARG0];
    print "DEBUG: irc_whois fired.\n";
}

Unfortunately, the event can't fire while the loop is running so this hangs. I'm sure there's a better way to do this, but I'm not familiar enough with this kind of programming to know. Any help would be greatly appreciated.

Solution

The following applies to FreeNode at least (or any server supporting the identify-msg feature).

If you are reacting to a message (irc_msg, irc_public, or irc_ctcp_action) from a user, you can tell whether he has identified to NickServ by looking at the third argument ($_[ARG3]) provided to the event handler. It will be true if the user has identified, false otherwise.