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

[Chet Ramey]

On 7/31/24 11:40 AM, Zachary Santer wrote:
> On Fri, Jul 26, 2024 at 10:37 AM Chet Ramey <chet.ramey@case.edu> wrote:
> > On 7/20/24 1:50 PM, Zachary Santer wrote:
> > > 'wait' without -n or pid arguments doesn't look in the list of saved
> > > pids and statuses simply because it would serve no purpose for it to
> > > do so. The return status will be 0, no matter how any child process
> > > terminated, or even if there never was a child process. *
> > >
> > > For 'wait -n', on the other hand:
> > > "If the -n option is supplied, wait waits for a single job from the
> > > list of ids or, if no ids are supplied, any job, to complete and
> > > returns its exit status."
> > > People are going to naturally expect 'wait -n' without pid arguments
> > > to return immediately with the exit status of an already-terminated
> > > child process, even if they don't provide id arguments. In order to do
> > > so, 'wait -n' obviously has to look in the list of saved pids and
> > > statuses.
> >
> > I think the part you're missing is that processes get moved to this list
> > after the user has already been notified of their termination status.
>
> I think I was missing more than that. Was the original 'wait -n'
> discussion from January specific to its use within the interactive
> shell?

No, it was due to processes exiting due to signals. But you could have
looked that up yourself.

--
``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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