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From: Dan Cross <crossd@gmail.com>
To: Douglas McIlroy <douglas.mcilroy@dartmouth.edu>
Cc: TUHS main list <tuhs@minnie.tuhs.org>
Subject: Re: [TUHS] moving directories in svr2
Date: Wed, 29 Dec 2021 15:15:48 -0500	[thread overview]
Message-ID: <CAEoi9W7EGSnf_UmSNTPF3Qq9gDbOKmrLm-k-RjiJz7+OOgQA-g@mail.gmail.com> (raw)
In-Reply-To: <CAEoi9W4OgF1wKwdeRVB_-0tWQsHTt+J5H3-yTVPDAyphUCkAqA@mail.gmail.com>

On Wed, Dec 29, 2021 at 2:37 PM Dan Cross <crossd@gmail.com> wrote:
> The 4.3BSD man page has this gem: "Hard links may not refer to
> directories (unless the proper incantations are supplied) and may not
> span file systems." And indeed, a quick look at /usr/src/bin/ln.c on a
> VAX running 4.3 shows that it has an undocumented `-f` flag:
> presumably the "proper incantation" mentioned in the man page.

On a lark, I decided to check for this on 7th Edition as well. The man
page says, quite clearly: "It is forbidden to link to a directory or
to link across file systems." However, /usr/src/cmd/ln.c has the
undocumented `-f` flag, and if given, will elide checking for whether
the "name1" argument is a directory or not. Looking at the kernel, as
Doug mentioned, one must be the superuser to link a directory.

        - Dan C.

  reply	other threads:[~2021-12-29 20:16 UTC|newest]

Thread overview: 71+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-29 19:13 Douglas McIlroy
2021-12-29 19:37 ` Dan Cross
2021-12-29 20:15   ` Dan Cross [this message]
2021-12-29 20:42     ` Richard Salz
2021-12-29 20:58       ` Dan Cross
2021-12-29 21:20         ` Clem Cole
2021-12-30  3:15       ` Bakul Shah
  -- strict thread matches above, loose matches on Subject: below --
2021-12-30  3:45 Noel Chiappa
2021-12-30  4:02 ` Bakul Shah
2021-12-30 16:40 ` Theodore Ts'o
2021-12-30 22:31   ` Dan Cross
2021-12-31  0:43     ` Bakul Shah
2021-12-31  1:00       ` Rob Pike
2021-12-31  1:45         ` Bakul Shah
2021-12-31  2:23           ` Adam Thornton
2021-12-31 18:56       ` Chet Ramey
2021-12-31  3:08     ` Theodore Ts'o
2021-12-31  3:23       ` Rob Pike
2021-12-31  5:16         ` Theodore Ts'o
2021-12-31  5:21           ` Dan Cross
2021-12-31  5:55           ` Rob Pike
2021-12-31 13:32             ` Michael Kjörling
2021-12-31 15:53               ` Adam Thornton
2021-12-31 16:13                 ` Arthur Krewat
2021-12-31 18:17                 ` Dan Cross
2021-12-31 18:23                   ` Larry McVoy
2021-12-31 18:37                     ` Dan Cross
2021-12-31 18:29                   ` Arthur Krewat
2022-01-01  0:09                   ` Theodore Ts'o
2022-01-03 13:35                     ` Dan Cross
2022-01-03 20:23                       ` Theodore Ts'o
2022-01-03 20:45                         ` Warner Losh
2022-01-03 21:15                         ` Dan Cross
2022-01-03 22:26                           ` Theodore Ts'o
2022-01-03 23:10                             ` Dan Cross
2022-01-04 15:45                             ` Chet Ramey
2022-01-09 19:28                             ` Larry McVoy
2022-01-03 23:21                           ` Doug McIntyre
2022-01-03 23:37                             ` Adam Thornton
2022-01-04 14:49                               ` Stuart Remphrey
2022-01-03 23:44                             ` Larry McVoy
2022-01-03 23:56                               ` Warner Losh
2022-01-04  2:28                               ` Theodore Ts'o
2022-01-04  2:42                                 ` Larry McVoy
2022-01-03 22:57                         ` Phil Budne
2021-12-31  5:12       ` Bakul Shah
2021-12-29 19:33 Noel Chiappa
2021-12-30  3:40 ` Jay Logue via TUHS
2021-12-29 17:12 Douglas McIlroy
2021-12-29 16:59 Bakul Shah
2021-12-29 17:04 ` Clem Cole
2021-12-29 17:14 ` arnold
2021-12-29 17:38   ` Clem Cole
2021-12-29 17:49     ` Brantley Coile
2021-12-29 18:27       ` ron minnich
2021-12-29 20:59         ` Rob Pike
2021-12-29 14:33 Will Senn
2021-12-29 15:02 ` arnold
2021-12-29 15:38   ` Will Senn
2021-12-29 15:44     ` Richard Salz
2021-12-29 16:17       ` Clem Cole
2021-12-29 16:58         ` Richard Salz
2021-12-30  5:14         ` Dan Stromberg
2021-12-30 16:22           ` Clem Cole
2021-12-30 18:02           ` John Cowan
2021-12-30 23:04             ` Richard Salz
2021-12-29 15:17 ` Clem Cole
2021-12-29 15:44   ` Will Senn
2021-12-29 16:10     ` Clem Cole
2021-12-29 16:33       ` Warner Losh
2021-12-29 16:01   ` Bakul Shah

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