async def prompt(self, text=None):
        '''
        Prompt for user input from stdin.
        '''
        if self.sess is None:
            hist = FileHistory(s_common.getSynPath('cmdr_history'))
            self.sess = PromptSession(history=hist)

        if text is None:
            text = self.cmdprompt

        with patch_stdout():
            retn = await self.sess.prompt(text, async_=True, vi_mode=self.vi_mode, enable_open_in_editor=True)
            return retn
Prompt for user input from stdin.