Re: 'wait -n' with and without id arguments

[Chet Ramey]

On 9/22/24 1:48 PM, Zachary Santer wrote:
> If you're not going to make 'wait -n' without id
> arguments pull something from the bgp list, then the 'set -o posix'
> notification behavior ought to be made the default behavior, yeah.

I think keeping posix mode behavior is fine.

> > Like `set -b'?
>
> Yeah, that really needs to be mentioned explicitly. 

The job control section already mentions notify, and the latest (heavily
edited) versions mention that jobs are removed from the jobs table when
the user is notified.


> If the default
> notification behavior stays as is, it should also mention that 'wait
> -n' without id arguments in the interactive shell, with 'set -m'
> enabled, requires that 'set -o posix' be enabled as well, for reliable
> I could see putting all that in the BUGS section.

It's not a bug. I mean, I know there's some stuff in the BUGS section
that's not a bug that's been there for a while, but this isn't a bug.
It's just how notify works.

> I know I never looked at it before I got burnt the first time.

Apparently.

> > > B) Solve 'wait -n' inconsistency by allowing it to act on the list of
> > > saved pids and statuses of jobs whose termination has already been
> > > notified to the user:
> > > - POSIX doesn't agree with the existence of that list
> >
> > POSIX says everything should disappear when you get notified or the
> > subject of `wait', so there's that (bash just does it on `wait'). Those
> > semantics have defenders just as ardent as you are.
>
> Maybe those defenders can elucidate what purpose that behavior would serve.

kre's on the list, maybe he'll speak up. I'm not going to speak for him.
He's written about this before.

https://lists.gnu.org/archive/html/bug-bash/2024-08/msg00124.html
https://lists.gnu.org/archive/html/bug-bash/2024-08/msg00179.html

> At the end of the day, B) is by far the simpler solution, and wouldn't
> leave a bunch of configurations where 'wait -n' doesn't really work
> quite right in the interactive shell.

It will work that way in posix mode for now.

--
``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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