From: Gene Pavlovsky <gene.pavlovsky@gmail.com>
To: cygwin@cygwin.com
Subject: Re: `CYGWIN=winsymlinks:nativestrict`, `ln -s target link` fails if target doesn't exist
Date: Fri, 29 Apr 2016 00:09:00 -0000 [thread overview]
Message-ID: <CAPTiy3OZC7acPvJRN0QtqjzfcFpnoxJkud3MTKQQVTCRr6vJVg@mail.gmail.com> (raw)
In-Reply-To: <1606116423.20160429020650@yandex.ru>
I don't know if POSIX standard has something to say about that, but
here's a reference from GNU libc:
`man 2 symlink`:
> A symbolic link (also known as a soft link) may point to an existing file or to a nonexistent one; the latter case is known as a dangling link.
On 29 April 2016 at 02:06, Andrey Repin <anrdaemon@yandex.ru> wrote:
> Greetings, Gene Pavlovsky!
>
>> I have an issue to report:
>
>> Introduction: On a UNIX system, `ln -s target link` creates a link
>> regardless of target's existence.
>> This is used in some scripts, e.g. Gentoo's `run-crons` (which I also
>> use on Cygwin) uses a symlink pointing to the running process PID as
>> lockfile.
>> Issue: if `CYGWIN=winsymlinks:nativestrict` env var is set, running
>> `ln -s target link` completely fails (even though running `mklink link
>> target` in `cmd.exe` succeeds, same as `ln -s` does on UNIX). If
>> `CYGWIN=winsymlinks:native`, a non-native link is created.
>
>> So, `nativestrict` might break some (admittedly unorthodox) scripts.
>> With `native` these script work, but still a native link would be
>> preferrable and it is possible to create, but a non-native link is
>> created instead.
>
>> Bottom line, I think the native symlink creation code should be
>> checked and a possibility should be added to create links to
>> non-existent targets, rather than the current behavior of failing.
>
> This is actually an arguable behavior, even in Linux. I can imagine the
> behavior is "undefined" in such a case.
> But I'll leave final say to the more experienced members of the list.
>
>
> --
> With best regards,
> Andrey Repin
> Friday, April 29, 2016 01:55:21
>
> Sorry for my terrible english...
>
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next prev parent reply other threads:[~2016-04-29 0:06 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-28 22:18 Gene Pavlovsky
2016-04-28 23:48 ` Andrey Repin
2016-04-29 0:06 ` Eric Blake
2016-04-29 5:23 ` Andrey Repin
2016-04-29 0:09 ` Gene Pavlovsky [this message]
2016-04-29 1:46 ` Gene Pavlovsky
2016-04-29 12:03 ` Gene Pavlovsky
2016-04-29 12:15 ` Peter Rosin
2016-04-29 12:20 ` [cygwin] " Jason Pyeron
2016-04-30 12:35 ` Gene Pavlovsky
2016-10-05 3:56 ` Rinrin
2016-10-05 4:31 ` Marco Atzeri
2016-10-06 10:38 ` Gene Pavlovsky
2016-10-07 5:33 ` Rinrin
2016-10-09 19:16 ` Gene Pavlovsky
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