On 2018-02-01, at 10:28:47, Kirk Wolf wrote:
> With bash you can handle multiple pipes at once without explicit named
> pipes ("process redirection"),
>
Also Korn Shell. I'm aware of the construct; I haven't mastered
it -- I try to stay in POSIX for portability. But does it have
the flexibility of either C or CMS Pipelines? I could wish
/bin/sh had the equivalent of Rexx "SYSCALL pipe" (sort of like
ADDPIPE/ADDSTREAM).
Interestingly, while z/OS shell indicates syntax error on an
attempted process redirection, it reports with a unique message.
Apparently the authors were aware but chose not to implement it.
> and you can also get a completion statusarray ("PIPESTATUS[i]")
> from a multi-stage pipe.
>
Valuable indeed. I often wish for it. (How would I do that
with CMS Pipelines?
> Pity there is no z/OS
> port of bash that supports local spawn, which is important in many cases.
>
True.
> On Thu, Feb 1, 2018 at 10:12 AM, Rob van der Heij wrote:
>
>> On 1 February 2018 at 16:40, Paul Gilmartin wrote:
>
> On Thu, Feb 1, 2018 at 10:12 AM, Rob van der Heij wrote:
>>
>>
>>>> with a multi-stream pipeline topology ...
>>>
>>> That restriction is a myth. C programs can deal with multi-stream
>>> pipe topologies. In shell that requires named pipes.
>>
>> Because CMS Pipelines does not buffer the data, the flow of records in
>> different segments of the pipeline is predictable. Without that, even
>> simple plumbing does not work as I would expect.
>>
I agree.
>> With named pipes you have a bunch of programs using each others output, and
>> you don't really care when they do it.
>>
You might want to care; you just aren't allowed to.
-- gil
