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 31464 invoked from network); 21 Feb 2021 08:23:02 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 21 Feb 2021 08:23:02 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 60D5993DAD; Sun, 21 Feb 2021 18:22:58 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 9189E93D1B; Sun, 21 Feb 2021 18:22:22 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (1024-bit key; secure) header.d=drijf.net header.i=@drijf.net header.b="gVkjHHH3"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 9516A93D1B; Sun, 21 Feb 2021 18:22:17 +1000 (AEST) X-Greylist: delayed 401 seconds by postgrey-1.36 at minnie.tuhs.org; Sun, 21 Feb 2021 18:22:15 AEST Received: from clue.drijf.net (clue.drijf.net [94.142.244.34]) by minnie.tuhs.org (Postfix) with ESMTPS id C202493D06 for ; Sun, 21 Feb 2021 18:22:15 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=drijf.net; s=default; t=1613895331; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=K5ENb8aLDQ8rgxvH7a7lJ/dDlalpN6gWuK+0npbmrS0=; b=gVkjHHH3wJG+CF9Y4mrClnthpYjTk22OiDmt6JSH4R4qXvLSnFjZxlzmVc0px0Z9Qxt1zI z7x48cH9BRdkVXbXPMxQ3dpAufYui9OXmoCazNWHld/TmT1m85D5TrIyYG7EZyiQGeNFE9 z9vQYtID9pKTXR9V76yT+t/E6NcIWoI= Received: from clue.drijf.net (clue.drijf.net [94.142.244.34]) by mx1.drijf.net (OpenSMTPD) with ESMTPSA id 469ec3ca (TLSv1.3:AEAD-AES256-GCM-SHA384:256:NO); Sun, 21 Feb 2021 09:15:31 +0100 (CET) Date: Sun, 21 Feb 2021 09:15:29 +0100 From: Otto Moerbeek To: M Douglas McIlroy Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [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: , Cc: tuhs@minnie.tuhs.org Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" On Sat, Feb 20, 2021 at 06:09:42PM -0500, M Douglas McIlroy wrote: > > - 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 I always wonder how to distunguish data and programs when people want to separate them. One person's data is another person's program and vice versa. Think scripting, config files, grammar definitions, postscript files, exectuables to be fed to emulators, compilers, linkers, code analysis tools, the examples are endless. Turing already saw that form the theoretical point of view, others (like Von Neumann) more from the practical persppective. Data = Programs. -Otto