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From: Paul Eggert <eggert@cs.ucla.edu>
To: Michael Albinus <michael.albinus@gmx.de>
Cc: emacs-devel@gnu.org
Subject: Re: master 9d626df: Add 'nofollow' flag to set-file-modes etc.
Date: Mon, 24 Feb 2020 16:25:51 -0800	[thread overview]
Message-ID: <f35c0721-4b15-36f0-d53f-5b872b5f5729@cs.ucla.edu> (raw)
In-Reply-To: <87blpow0s6.fsf@detlef.i-did-not-set--mail-host-address--so-tickle-me>

On 2/24/20 5:52 AM, Michael Albinus wrote:

> However, for POSIX shells it is different. FreeBSD supports the "chmod
> -h" argument, which implements nofollow. See
> <https://www.freebsd.org/cgi/man.cgi?chmod>. I could check for this
> argument, and use if possible.
> 
> But what shall I do if the target system runs GNU/Linux? chmod(1) does
> not offer any comparable argument. Shall I simply ignore nofollow there?

How about something like this?

if (chmod -h works); then
   chmod -h MODE FILE
elif (test -h works); then
   test -h FILE && chmod MODE FILE
else
   chmod MODE FILE
fi

I'm suggesting 'test -h' rather than 'test -L' here because some ancient 
platforms support the former but not the latter.

> Does anybody know, whether there are plans to extend chmod accordingly,
> for example the version in coreutils? Or is there an alternative
> possiblity to change the permission of the symbolic link?

It should be added to the coreutils TODO list, if it's not there 
already. On GNU/Linux symlink modes cannot be changed, for what it's 
worth, so chmod -h would merely be a safety feature.



  reply	other threads:[~2020-02-25  0:25 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20200224004617.19362.5846@vcs0.savannah.gnu.org>
     [not found] ` <20200224004619.58020206ED@vcs0.savannah.gnu.org>
2020-02-24 13:52   ` master 9d626df: Add 'nofollow' flag to set-file-modes etc Michael Albinus
2020-02-25  0:25     ` Paul Eggert [this message]
2020-02-25  9:15       ` Michael Albinus
2020-02-25 23:02         ` Paul Eggert
2020-02-26  0:29           ` Michael Albinus
2020-02-25  9:23       ` Andreas Schwab

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