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=-0.8 required=5.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FROM,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 13901 invoked from network); 29 Dec 2021 20:59:05 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 29 Dec 2021 20:59:05 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id EBF5D9CF04; Thu, 30 Dec 2021 06:59:02 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id A1D719CEA9; Thu, 30 Dec 2021 06:58:50 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="O2LNC8WT"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id BEC1D9CE9F; Thu, 30 Dec 2021 06:58:47 +1000 (AEST) Received: from mail-ot1-f41.google.com (mail-ot1-f41.google.com [209.85.210.41]) by minnie.tuhs.org (Postfix) with ESMTPS id 228B59CE9F for ; Thu, 30 Dec 2021 06:58:47 +1000 (AEST) Received: by mail-ot1-f41.google.com with SMTP id j3-20020a056830014300b0058f4f1ef3c2so25891146otp.13 for ; Wed, 29 Dec 2021 12:58:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=RRYV+1oY/piV5ca/EvVatdS1v9s0YrVNxme6yBosJPE=; b=O2LNC8WTzITd2zsIwuiKYVt7JCqJ7oa/V5lCCDePlAfq9GUN00gGiYqmqE9V5lxXHu l51FW2hV/pvUVfTJ6g0Q0C1lst9Ts8T1g+rPhi+HSmpo2fSgoG83LaT/Mr++PI2RobKm ueo8tPfA0IwuOMy0ancNWUp82frnD7zZAkToDL8eSIFYoqwIFBtYEPisZKeMHHSP0fe3 hXWOc9r4snb4Dfn8npiGZK/7eR2KlgXwQ14UR1WWogP0UUcvSMPhT4W+Fp1hg3nt1xvv Y/ZY+9EaxoSRTsFjJRchvRcwY7ldYPuanxledXsjwvN45t10Qy6fvWs2AybBJlF6cJhh E36w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=RRYV+1oY/piV5ca/EvVatdS1v9s0YrVNxme6yBosJPE=; b=NoJTNq+naPpnGkIxa1zkE8y/i1Ty3czMQS5qJ0B4sJ79ps3XyiXxj8iqtZQgcL4wGG iFTHLBYZo8GnckpMubDyk3wY0+j02kRAi+c4oVlQfumeYg1DYNM9lWDIE8ysfZHyK4GT Mgk/OE6pUH3OhEDVbqbf81A3g72weCcLFYiK4Pe2awXNKjfzWtdLqLjtDu/FFThPSLKY mYOcE7b7GHedSFY7gaKHzYiYfleNpz1cyWneO/YxebJfPR22XKjk2RDTY0Abac5fvrzA rve5OpGZDzDzpcOZ+wDSlxIvNPbw/F64ilYe2hWThvUy1MsMAaV9SUoM40v3FqNnxTFW gLZg== X-Gm-Message-State: AOAM5315o2mfTVSP57x7tus0P+VUSGenXhtEuDVNVXfGl89ui2l+sRR6 cQNzQIfxt/Ca3bDeQPUvYmeYtOKL7vnkKfOecv0= X-Google-Smtp-Source: ABdhPJy4tl4I1DRloyZwfuAbujtvkIGfKYxQoJBpTgzVTv91816+MdOyKL8hpuYw03XtfYOq+MyKQjj+W6jQHKpND3Q= X-Received: by 2002:a9d:6acb:: with SMTP id m11mr16859521otq.375.1640811526301; Wed, 29 Dec 2021 12:58:46 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Dan Cross Date: Wed, 29 Dec 2021 15:58:10 -0500 Message-ID: To: Richard Salz Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [TUHS] moving directories in svr2 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 main list , Douglas McIlroy Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" Partitioning the tree sure seems like it would lead to a bad day, doesn't i= t? I expect the undocumented arcana related to linking directories was always an escape hatch for a skilled administrator to rescue a sick system. One can imagine any number of ways in which directory files could be corrupted; sufficient inspection of disk contents might give someone with the requisite low-level knowledge sufficient information that they could, say, reattach a pruned subtree with clever uses of `ln -f` and `unlink`. Did `icheck` and friends have something analogous to the `lost+found` directory created by `fsck`? I could imagine (somewhat painfully) executing those commands while in single-user mode on the console. - Dan C. On Wed, Dec 29, 2021 at 3:42 PM Richard Salz wrote: > > https://dsf.berkeley.edu/cs262/unix.pdf section 3.2 ends with: > > Each directory always has at least two entries. The > name "." in each directory refers to the directory itself. Thus a > program may read the current directory under the name =E2=80=9C.=E2=80=9D > without knowing its complete path name. The name =E2=80=9C..=E2=80=9D by > convention refers to the parent of the directory in which it > appears, that is, to the directory in which it was created. > The directory structure is constrained to have the form > of a rooted tree. Except for the special entries =E2=80=9C.=E2=80=9D and = =E2=80=9C..=E2=80=9D, > each directory must appear as an entry in exactly one other, > which is its parent. The reason for this is to simplify the > writing of programs which visit subtrees of the directory > structure, and more important, to avoid the separation of > portions of the hierarchy. If arbitrary links to directories > were permitted, it would be quite difficult to detect when > the last connection from the root to a directory was severed