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

[Robert Elz]

    Date:        Wed, 14 Aug 2024 15:21:44 -0400
    From:        Chet Ramey <chet.ramey@case.edu>
    Message-ID:  <1413a9a0-cbef-44c5-8072-a3be7294e8e0@case.edu>

  | I'm not sure returning the status of some random process from some
  | arbitrary point in the past is going to be valuable.

Not "some random process" but a process that has terminated, and hasn't
been waited upon before (and which hasn't been notified as complete via
an explicit user execution of the "jobs" command or the implicit "jobs"
which runs just before each PS1 output in an interactive shell).

  | Maybe the thing to do is to retain jobs in the job list, even after
  | they're marked as notified,

I'd do the opposite, once they're notified, they should be deleted
from the jobs table, and everywhere else.   But "notified" only happens
when the script explicitly asks (in a non-interactive shell, never because
of any other event than an appropriate command issued by the script, and
in an interactive shell, the same, or the implicit "jobs" before each PS1).

Once deleted, they're gone, and there's no way to get data from them,
ever again.

This should not require any magic options.

If something is notified because it has stopped, rather than terminated
(which with "wait" really should require a new wait option) then obviously
it isn't removed, but still cannot be waited upon again until after it
has resumed running, and then stopped/terminated after that (resumed
includes for the very briefest instant if the job is killed while stopped).

kre