control options from cmdline

def command(self, args):
        '''control options from cmdline'''
        if len(args) == 0:
            self.show_all()
            return
        if getattr(self, args[0], [None]) == [None]:
            print("Unknown setting '%s'" % args[0])
            return
        if len(args) == 1:
            self.show(args[0])
        else:
            self.set(args[0], args[1])