Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!mips!apple!vsi1!zorch!xanthian
From: xanthian@zorch.SF-Bay.ORG (Kent Paul Dolan)
Newsgroups: comp.sys.amiga.tech
Subject: Re: PIPEs
Message-ID: <1990Nov8.101107.5884@zorch.SF-Bay.ORG>
Date: 8 Nov 90 10:11:07 GMT
References: <6990@sugar.hackercorp.com> <2641@mtecv2.mty.itesm.mx> <7005@sugar.hackercorp.com>
Organization: SF-Bay Public-Access Unix
Lines: 45

peter@sugar.hackercorp.com (Peter da Silva) writes:

>Right, which is why I came up with the idea for a "pipe" command that works
>like "run", and will provide piping for all shells and Amigas:

>pipe cmd1 args +
>cmd2 args +
>cmd3 args
>
>Solves the metacharacter conflict problem nicely.


I like the "+" convention, but I'd rather use "-<" and ">-" with it, so
that I could say:

            cmda args -<{1,2}   +
            cmdb args -<{1,2,3} +
        >-1 cmdc args -<2       +
        >-2 cmdd args -<4       +
        >-3 cmde args -<1       +
        >-4 cmdf args           > result

and have cheap to type, multiple input, multiple output "named" pipes, with
the unlabeled version

           cmda args -< +
        >- cmdb args -< +
        >- cmdc args    > result

just passing stuff to the next line.

This would be a nice syntax for Pete Goodeve's pipe mechanism (which
does its interleave synchronization at the message-full level) when he
gets the fan-out side working to go along with the fan-in side.

The fan-out appearance of "-<" and the  fan-in appearance of ">-" give these
a nice intuitive appearance, IMHO.

Whether the command line processor would be happier if all this started
with Peter da Silva's "pipe" verb is up to the implementors; it might be
easier for the human reader in any case, especially when trying to decipher
someone else's command script.

Kent, the man from xanth.
<xanthian@Zorch.SF-Bay.ORG> <xanthian@well.sf.ca.us>