search_by_tags(split ',', $cgi->param('tags'));

##</code><code>##

search_by_tags($cgi->param('tags')); # split called inside this function

##</code><code>##

###index.pl
use Controller::Admin;
Controller::Admin->new()->run();
###Controller/Admin.pm
sub run(){
    my $auth = Controller::Auth->new();
    $auth->loggedin() or $auth->require_login(); return; # that prints login page
    #
    #Do some tasks if the user has logged in
    #
}

##</code><code>##

###index.pl
use Controller::Admin;
print Controller::Admin->new()->run();
###Controller/Admin.pm
sub run(){
    my $auth = Controller::Auth->new();
    $auth->loggedin() or return $auth->require_login(); # that RETURNS login page
    #
    #Do some tasks if the user has logged in
    #
}