sub get_file_watcher_ref {
    my %setting_for;
    my @interesting_keys = qw(
        watch_interval
        watch_file_min_size
        term_run_time
    );
    
    for (@interesting_keys) {
        if ($config->{$_}) $setting_for{$_} = $config->{$_};
    }
    
    return \%setting_for;
}