Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com
Date: Sat, 27 Aug 2005 10:44:58 +0200
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: Problem with sh/bash and snapshot cygwin1-20050825.dll
Message-ID: <20050827084458.GM17452@calimero.vinschen.de>
Reply-To: cygwin AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
References: <430E9B0B DOT 8040303 AT scytek DOT de> <20050826052618 DOT GC4087 AT trixie DOT casa DOT cgf DOT cx> <20050826090717 DOT GB21203 AT calimero DOT vinschen DOT de> <430F0849 DOT 8040002 AT byu DOT net> <20050826123244 DOT GA23422 AT calimero DOT vinschen DOT de> <430F7BD7 DOT 5000406 AT byu DOT net>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <430F7BD7.5000406@byu.net>
User-Agent: Mutt/1.4.2i

On Aug 26 14:30, Eric Blake wrote:
> $ readlink u
> x
> $ ls x*
> x.exe
> $ ls -lF x
> - -rwxr-xr-x  1 eblake None 13961 Mar 10 06:54 x*
> $ file x    # See below for more on this...
> x: writable, executable, regular file, no read permission
> $ ./myreadlink u/blah
> 'u/blah': NULL, 2 No such file or directory
> 
> You are right that the code is correctly giving ENOTDIR when the symlink
> isn't half-dangling (ie stat() succeeds but open() fails):
> $ readlink u.exe
> x.exe
> $ ./myreadlink u/blah
> 'u/blah': NULL, 20 Not a directory

That's a result of attaching .exe to symlinks.  When iterating over
paths, the .exe suffix is only checked on the last component, never
on inner (== directory) components.  This makes sense, otherwise every
component has to tested twice as often, which would slow down Cygwin
a lot.  I don't see a good reason to change that, just for the
(questionable) success, to exchange one errno for another.

After all, EINVAL is correct, as would be ENOTDIR.  I don't see that
POSIX demands an order of errnos in the case where two or more different
errnos are correct.  For instance, consider a function which treats
the first parameter as invalid if it's NULL, and which copies something
into the space where the second parameter points to:

  int err = foo (NULL, (void *) 0x01);

Which errno is correct to return, EINVAL or EFAULT?

Btw., what was the exact reason to attach the .exe suffix to symlinks
pointing to executables?  I fail to see the advantage, right now.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          mailto:cygwin AT cygwin DOT com
Red Hat, Inc.

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/