Re: 5.3-alpha: the `jobs' builtin prints foreground dead jobs with function substitutions

[Chet Ramey]

On 5/1/24 10:38 PM, Koichi Murase wrote:
> 2024年5月1日(水) 22:58 Chet Ramey <chet.ramey@case.edu>:
> > Yes, and I said I could work around this case.
>
> Thank you for your consideration.
>
> > > [1] https://lists.gnu.org/archive/html/bug-bash/2022-10/threads.html#00054
> > > [2] https://lists.gnu.org/archive/html/bug-bash/2022-11/threads.html#00049
> > > (continued. I haven't received a reply)
> >
> > To what?
>
> To the email [2]. In particular, to the question in the second paragraph [2].

OK. No, it doesn't make sense to do that.

The better option is to change the notification strategy so that the jobs
list doesn't contain terminated unnotified foreground jobs when run in a
trap.

I assume a similar solution would work for `bind -x' and $PROMPT_COMMAND,
but I haven't looked at those yet.


> > > I'm not sure about the answer, but kre's opinion seems reasonable to
> > > me.
> >
> > OK. The standard does say "reporting the exit status with the special
> > parameter '?'" in
> >
> > https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_08_02
>
> I think the description of the standard is still unclear, or the
> standard doesn't try to specify this detail. 

Probably the latter.


> > and hit the `sleep' with SIGUSR1 from another process, all shells will
> > print some message about the process exiting due to SIGUSR1 before `jobs'
> > is executed, and `jobs' prints nothing, because the reporting has already
> > happened.
>
> In that theory, what happens when `sleep 20' is successfully
> terminated without any signals? 

Shells wouldn't, and don't, notify about that.

> With this interpretation, the `jobs' builtin will never print
> foreground jobs because, at the point when the `jobs' builtin is
> running in the foreground, any other foreground jobs should have been
> terminated (while setting $?) or turned into background jobs as no
> more than one jobs can run in the foreground at the same time. 

Sure. In addition, I want to preserve the behavior of notifying about
terminated foreground jobs that were killed by a signal we don't ignore.

--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/

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