From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 3337 invoked from network); 20 Feb 2021 23:10:40 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 20 Feb 2021 23:10:40 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id AB53F93D2D; Sun, 21 Feb 2021 09:10:33 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 69ADC93D1B; Sun, 21 Feb 2021 09:10:06 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (2048-bit key; unprotected) header.d=dartmouth.edu header.i=@dartmouth.edu header.b="AjFIIKET"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 9297493D1B; Sun, 21 Feb 2021 09:10:00 +1000 (AEST) Received: from mail-wr1-f54.google.com (mail-wr1-f54.google.com [209.85.221.54]) by minnie.tuhs.org (Postfix) with ESMTPS id 7C1FE93D06 for ; Sun, 21 Feb 2021 09:09:59 +1000 (AEST) Received: by mail-wr1-f54.google.com with SMTP id r3so3316684wro.9 for ; Sat, 20 Feb 2021 15:09:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dartmouth.edu; s=google1; h=mime-version:from:date:message-id:subject:to; bh=j7M0aLw4UTp7nEs1EgNwCXiZTlIHpblqDVE5o/WJEhE=; b=AjFIIKETRsq1G1lqBGW/WbRWMJcjwQYACnfMu0/T80faADcZXqX0ShQ52Sy/Y/oXPu Jy3nDagN3hkG+/WKGSPl1TY55VHyV2ygFLgA9b6mOEc0ste4kQF7U5qGPqonYSvlO18x 7hvQZa1kV5DWzSF1gfwspQnqYrQjQcQw68Oc1ttS5GEfykIO0NLH+psN6YDd/v8a5z0b yfWkNeGe4vniknhiSsNZUq+DSTjK/2PnrI1xBs08MnlHxq8Aeus/Rbqxs7Gjc4hYbtl9 LTmkqfen+ztXl/5PWKY0EgpeiCGJ6QYnyVgMyoDovWSFC7RTJ7Z5gVPgtTK8KtowVxjk ciGA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=j7M0aLw4UTp7nEs1EgNwCXiZTlIHpblqDVE5o/WJEhE=; b=dcRCA27prr98viH0ALWFk6bj0yvBitM/AXVDbhllGlmC3IFfHIVifg2cpIsXFnmypP 8lTbKYVmu2zITpFQa1dxte68n6jcA6iPAGIXRZBjntzOTQCfz7W7sTCV+G8yDXXNOfI3 7X6uJ/Z40qLsJ2BMGSALXR+Afrw+QISiw2+NFKPsPFVAf956rOY+zsDsvtjKFEd5rtDy Q+wLBZBqzRA+RyVbe063UbIqLGLbgkMuPyFJGA8tV4tC1zHsuYEoN2mjBPOl/sWgOVCb +8yd+3H6JCtDt3ujpoubPGYx80dDv4AVoSxhlGWE6qbtbthqeUykBwqOE8lfRY1nzS9S wqTA== X-Gm-Message-State: AOAM531QWlGacUM7NKcxcQY+Ovt0/kp3RxKyimocs8OtQI5Q/Ur5Arf3 XpGlpRWBM+FD38sT+KKECgKlgEiVHew/3UO5jUaUheo6Nec= X-Google-Smtp-Source: ABdhPJynJYJgQkp2uLcU0519PZ2V0mUyk4KqmkcZdipBHUSoiaoDdBMjDOfMo/ECktrQJyMNzc8R5xNmH5gLA+jaqjM= X-Received: by 2002:a05:6000:1565:: with SMTP id 5mr15489209wrz.109.1613862597554; Sat, 20 Feb 2021 15:09:57 -0800 (PST) MIME-Version: 1.0 From: M Douglas McIlroy Date: Sat, 20 Feb 2021 18:09:42 -0500 Message-ID: To: tuhs@minnie.tuhs.org Content-Type: text/plain; charset="UTF-8" Subject: [TUHS] Abstractions 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" > - separation of code and data using read-only and read/write file systems I'll bite. How do you install code in a read-only file system? And where does a.out go? My guess is that /bin is in a file system of its own. Executables from /letc and /lib are probably there too. On the other hand, I guess users' personal code is still read/write. I agree that such an arrangement is prudent. I don't see a way, though, to update bin without disrupting most running programs. Doug