From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.2 Received: (qmail 3474 invoked from network); 23 Apr 2020 13:49:49 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with UTF8ESMTPZ; 23 Apr 2020 13:49:49 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 5B3AF9BB31; Thu, 23 Apr 2020 23:49:42 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id D56B494B38; Thu, 23 Apr 2020 23:49:06 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=planet.nl header.i=@planet.nl header.b="gyLsoyHK"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 3179994617; Thu, 23 Apr 2020 23:49:02 +1000 (AEST) Received: from cpsmtpb-ews06.kpnxchange.com (cpsmtpb-ews06.kpnxchange.com [213.75.39.9]) by minnie.tuhs.org (Postfix) with ESMTP id D2EF69448B for ; Thu, 23 Apr 2020 23:48:57 +1000 (AEST) Received: from cpsps-ews23.kpnxchange.com ([10.94.84.189]) by cpsmtpb-ews06.kpnxchange.com with Microsoft SMTPSVC(8.5.9600.16384); Thu, 23 Apr 2020 15:48:55 +0200 X-Brand: 7abm2Q== X-KPN-SpamVerdict: e1=0;e2=0;e3=0;e4=(e1=10;e3=10;e2=11;e4=10);EVW:Whi te;BM:NotScanned;FinalVerdict:Clean X-CMAE-Analysis: v=2.3 cv=WNfkokkR c=1 sm=1 tr=0 cx=a_idp_e a=WB5lYbMG1jvHJ1f8o08CVQ==:117 a=soxbC+bCkqwFbqeW/W/r+Q==:17 a=x1i13A_MHe4A:10 a=IkcTkHD0fZMA:10 a=cl8xLZFz6L8A:10 a=DN2YFtG0RJyhEkJ_3rsA:9 a=QEXdDO2ut3YA:10 X-CM-AcctID: kpn@feedback.cloudmark.com Received: from smtp.kpnmail.nl ([195.121.84.14]) by cpsps-ews23.kpnxchange.com over TLS secured channel with Microsoft SMTPSVC(8.5.9600.16384); Thu, 23 Apr 2020 15:48:55 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=planet.nl; s=planet01; h=to:date:message-id:subject:mime-version:content-type:from; bh=HbAfDqabDAI7STe2YZf+ROt46FO1WLcCxJORuUlVNqM=; b=gyLsoyHKtxeayU0eJlqddTqivU0u8dOXafVtHj1WZ8Bl0gMlRVNcLC9FJSImdeNCacCbwl0YAMUeH VJeVS1O4beX7H+lCJN0DWvZQDbfnnWEKQSCfElL+2XFgC4snRP3a8IF8hknpVyGkKmBiuDEVs57Wzl AjBBHM8iw1JOlaPE= X-KPN-VerifiedSender: Yes X-CMASSUN: 33|TyahrQSF7kcVi0P5mcBYAH5qWkf2EGEMFfbShG6fhlOsTygHZVepXdKum2nxUYg cD5AT2zY1wCJD2ybf1s+AIQ== X-Originating-IP: 80.101.112.122 Received: from mba2.fritz.box (sqlite.xs4all.nl [80.101.112.122]) by smtp.kpnmail.nl (Halon) with ESMTPSA id 2c70fa0c-8569-11ea-b75f-00505699d6e5; Thu, 23 Apr 2020 15:48:55 +0200 (CEST) From: Paul Ruizendaal Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.11\)) Message-Id: <57D2AE85-21DB-4D8F-8211-8ED7C1E60421@planet.nl> Date: Thu, 23 Apr 2020 15:48:55 +0200 To: TUHS main list X-Mailer: Apple Mail (2.3445.104.11) X-OriginalArrivalTime: 23 Apr 2020 13:48:55.0528 (UTC) FILETIME=[EE620E80:01D61975] X-RcptDomain: minnie.tuhs.org Subject: [TUHS] V3 pipes X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" Was looking into pipes. For the 3rd Edition TUHS does not have source, but is does have a man = page. In V3, pipe returns a single file descriptor that echoes whatever = is written back upon reading. The pipe buffer capacity is 504 bytes. The surviving =E2=80=98nsys=E2=80=99 source for V4 does not yet include = the source for pipes, but the man page for 4th edition pipes has - more = or less - the well known semantics, including the 4096 byte buffer = capacity. Does anyone remember: - why the single fd approach was abandoned? To its credit, it appears to = allow for limited 2-way communication. Maybe the reason was that it = becomes harder to detect broken pipes? - whether the V3 implementation was based on an in-memory approach and = not the later 'anonymous backing file=E2=80=99? The 504 byte buffer = capacity suggests a single buffer page minus some header info.=