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From: arnold@skeeve.com
To: clemc@ccc.com, bakul@iitbombay.org
Cc: tuhs@minnie.tuhs.org
Subject: Re: [TUHS] moving directories in svr2
Date: Wed, 29 Dec 2021 10:14:44 -0700	[thread overview]
Message-ID: <202112291714.1BTHEiXo008223@freefriends.org> (raw)
In-Reply-To: <A26707C7-C43E-4A52-9405-B442C9412989@iitbombay.org>

Bakul Shah <bakul@iitbombay.org> wrote:

> 
> On Dec 29, 2021, at 8:01 AM, Bakul Shah <bakul@iitbombay.org> wrote:
> > On Dec 29, 2021, at 7:18 AM, Clem Cole <clemc@ccc.com> wrote:
> >> 
> >> Think about the UNIX FS and the link system call. How is mv implemented?   You link the file to the new directory and the unlink it from the old one.   But a directory file can not be in two directories at the same time as the .. link would fail.
> > 
> > Don’t see why linking a dir in two places is a problem.
>
> To expand on this a bit, the “cd ..” case can be handled by not storing a ..
> link in a dir. in the first place! Store the $PWD path in the u struct. Then
> cd .. would simply lop off the last component, if one exists. Thus .. takes
> you back only on the path you used! This also takes care of the issue with
> symlinks (& does what csh did in user code).

Plan 9 eventually did something like this. I don't remember the
details.

Arnold

  parent reply	other threads:[~2021-12-29 17:15 UTC|newest]

Thread overview: 71+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-29 16:59 Bakul Shah
2021-12-29 17:04 ` Clem Cole
2021-12-29 17:14 ` arnold [this message]
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
  -- 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 19:13 Douglas McIlroy
2021-12-29 19:37 ` Dan Cross
2021-12-29 20:15   ` Dan Cross
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
2021-12-29 17:12 Douglas McIlroy
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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