From: Corinna Vinschen <corinna-cygwin@cygwin.com>
To: cygwin@cygwin.com
Subject: Re: mkdir(2) prefers EACCES over EEXIST
Date: Wed, 12 Jul 2017 08:46:00 -0000 [thread overview]
Message-ID: <20170712084546.GF30071@calimero.vinschen.de> (raw)
In-Reply-To: <20170712011209.GK17540@nullprogram.com>
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On Jul 11 21:12, Christopher Wellons wrote:
> This isn't _really_ a bug, more of an oddity. Calling mkdir(2) on an
> existing directory will fail with EACCES instead of EEXIST if the directory
> couldn't have been created in the first place. For example, this is the
> typical situation for /cygdrive/c:
>
> mkdir("/cygdrive/c", 0700);
> // errno == EACCES
>
> Or from the shell:
>
> $ mkdir /cygdrive/c
> mkdir: cannot create directory ‘/cygdrive/c’: Permission denied
>
> Compare that to Linux or *BSD (giving EEXIST):
>
> $ mkdir /etc
> mkdir: cannot create directory ‘/etc’: File exists
>
> $ mkdir /etc
> mkdir: /etc: File exists
>
> This behavior seems to be permitted by POSIX — both are valid reasons for
> this system call to fail — but it's a surprising result. I'd expect
> existence to take priority.
That's a result of calling the Windows function without prior check for
existence. The Windows function apparently prefers it's variation of
EACCES over EEXIST, *iff* the target of the function is a drive.
I don't think it's worth to add a check to mkdir for such a border
case, just to prefer one error code over another.
Corinna
--
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Maintainer cygwin AT cygwin DOT com
Red Hat
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prev parent reply other threads:[~2017-07-12 8:46 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-12 1:12 Christopher Wellons
2017-07-12 8:46 ` Corinna Vinschen [this message]
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