'execute a list of commands from a file'

def do_read(self, arg):

    try:
        if (not arg):
            self.display_error('usage:    read    <filename>')
            return
        with open(arg, 'r') as f:
            self.cmdqueue.extend(f.read().splitlines())
    except Exception as e:
        self.display_error(str(e))
