Harald van Dijk wrote, on 18 Mar 2025:
>
> On 18/03/2025 14:45, Geoff Clare via austin-group-l at The Open Group wrote:
> > Those shells also print "hello" without the redirection:
> >
> > $ sh -c 'set +m; echo hello | { cat & wait; }' # sh here is bash
> > hello
> > $ ksh93u+m -c 'set -o posix; set +m; echo hello | { cat & wait; }'
> > hello
> >
> > So this has nothing to do with 0<&0 - it's a non-conformance with the
> > non-job-control asynchronous AND-OR list requirements in some
> > circumstances.
>
> Huh, so they do.
>
> bosh also does the same.
>
> If bash, ksh, bosh all do the same thing, but POSIX specifies another thing,
> is there a rationale somewhere explaining why?
I can't think of any reason they would deliberately behave that way, so
unless one of the shell authors can come up with some justification, I'm
going to consider it a bug.
> But still, in bash, 0<&0 really does have this effect. Here is a better test
> case:
>
> $ bash -o posix -c 'cat & wait'
> <immediately exits>
> $ bash -o posix -c 'cat 0<&0 & wait'
> <waits for stdin>
Okay, looks like we'll need Chet's input on this part.
--
Geoff Clare <g.cl...@opengroup.org>
The Open Group, Apex Plaza, Forbury Road, Reading, RG1 1AX, England
