$PROMPT_COMMAND (WAS: Re: Using $PROMPT_COMMAND to beep depending on success/failure)

[Tony Baechler]

On 4/22/2016 2:09 PM, Lars Bjørndal wrote:
> Do any of you know of a way to get a number as the first cell(s)
> in the prompt indicating the error code of the previous command? E.g.
>
> 1[user at host ~]#
>
> if something gets wrong? If zero, I'd like to get no number output.
> I think that could be convenient when using braille.


There is probably a way in bash, like echoing $? at the beginning of the 
prompt. However, mksh does that automatically. I think zsh does as well.