use Storable;
	use Fcntl qw(:DEFAULT :flock);
	open(DF, "< " . $categoriesFile) or die "can't open " . $categoriesFile . ": $!";
	flock(DF, LOCK_SH) or die "can't lock " . $categoriesFile . ": $!";
	my @categories = retrieve(*DF);
	close(DF);
	return \@categories;