Re: Bug or not a bug? dot expansion in ob-shell

[Nick Dokos <ndokos@gmail.com>]

Hi Bastien,

Bastien <bzg@gnu.org> writes:

> Hi Diego,
>
> Diego Zamboni <diego@zzamboni.org> writes:
>
>> I'm late to the discussion so I apologize in advance, but this fix
>> seems counterintuitive to me. In my mind, for any shell code:
>>
>> - Return value: exit code of the last command
>> - Output: whatever the commands print
>
> Yes, that's what is *now* possible if you set
> ob-shell-return-value-is-exit-status to t.
>
> Unless I miss something, it was not possible before today.
>
> #+begin_src shell
> echo Hello!
> #+end_src
>
> would simply return "Hello!" as a return.
>
> No exit code was *never* output.
>
>> So to me, it's intuitive that =:exports value= would return the exit
>> code of the last command, and =:exports output= would produce the
>> output of the commands. I don't understand why a new option is
>> needed.
>
> ... because it was not the case before.  Or maybe *I* miss something.
>
> Can you show me something that was working before and that is not
> anymore?
>
> Thanks,

I welcome the fix but not the option: the option situation in Org mode
was pretty horrible, then ca 2010, you did a survey and some options
were eliminated (not sure about the year or whether it *was* you who
did the survey, but I'm pretty sure there was one): that was the right
direction to go, but it wasn't enough. Org mode needs to be put into
an option diet, so adding another one here (and a rather gratuitous
one in my view) is not the way to go.

`:results value' should *always* produce the value of the last expression,
which for shell programs is the exit status of the last command.

`:results output' should *always* produce all of the output of the program.

An argument can be made that `:results value' is the default, but it
is the less useful option for shell programs. So maybe for shell
blocks, make the default to be `:results output' instead: people get
what they always got before the fix without lifting a finger, the exit status
is now available with `:results value', and the option can go away
quietly and quickly, before it becomes another contributor to the Org
mode technical debt.

-- 
Nick

"There are only two hard problems in computer science: cache
invalidation, naming things, and off-by-one errors." -Martin Fowler