From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: from minnie.tuhs.org (minnie.tuhs.org [IPv6:2600:3c01:e000:146::1]) by inbox.vuxu.org (Postfix) with ESMTP id DCAE4306A7 for ; Thu, 5 Dec 2024 21:56:21 +0100 (CET) Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id E20E043E7D; Fri, 6 Dec 2024 06:56:16 +1000 (AEST) Received: from freefriends.org (frenzy.freefriends.org [198.99.81.75]) by minnie.tuhs.org (Postfix) with ESMTPS id A13B143E4F for ; Fri, 6 Dec 2024 06:56:10 +1000 (AEST) X-Envelope-From: arnold@skeeve.com Received: from freefriends.org (localhost [127.0.0.1]) by freefriends.org (8.16.1/8.16.1) with ESMTPS id 4B5KtYS8781858 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Thu, 5 Dec 2024 13:55:34 -0700 Received: (from arnold@localhost) by freefriends.org (8.16.1/8.14.7/Submit) id 4B5KtYf1781856; Thu, 5 Dec 2024 13:55:34 -0700 From: arnold@skeeve.com Message-Id: <202412052055.4B5KtYf1781856@freefriends.org> X-Authentication-Warning: frenzy.freefriends.org: arnold set sender to arnold@skeeve.com using -f Date: Thu, 05 Dec 2024 13:55:34 -0700 To: johnl@taugh.com, crossd@gmail.com, chet.ramey@case.edu References: <568FD44F-01FB-441B-846B-7D42C3A8E1FB@canb.auug.org.au> <20241205030843.8552FAB1EDA5@ary.qy> <2fd6a361-b26f-4ca4-9c65-b6ba0559644e@case.edu> In-Reply-To: <2fd6a361-b26f-4ca4-9c65-b6ba0559644e@case.edu> User-Agent: Heirloom mailx 12.5 7/5/10 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID-Hash: VBUMX7CNAKHCHYMHVE5NI6KDSJI54IYG X-Message-ID-Hash: VBUMX7CNAKHCHYMHVE5NI6KDSJI54IYG X-MailFrom: arnold@skeeve.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-tuhs.tuhs.org-0; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: tuhs@tuhs.org, marc.donner@gmail.com X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: Pipes (was Re: After 50 years, what has the Impact of Unix been?) List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Chet Ramey via TUHS wrote: > On 12/5/24 10:19 AM, Dan Cross wrote: > > > Unix pipelines, on the other hand, tend to be used in a manner that is > > strictly linear, without the fan-out and fan-in capabilities described > > by Morrison. Of course, nothing prevents one from building a > > Morrison-style "network" from Unix processes and pipes, though it's > > hard to see how that would work without something like `select`, which > > didn't yet exist in 1978. Regardless, Unix still doesn't expose a > > particularly convenient syntax for expressing these sorts of > > constructions at the shell. > > Process substitution is about as close as we can get, but most programs > still process their filename arguments one at a time, beginning to end. > > The canonical process substitution example is > > diff <(old-program-version) <(new-program-version) > > to do simple regression testing. And fanout is simply ... | tee >(pipeline1) >(pipeline2) Arnold