X-Recipient: archive-cygwin@delorie.com
X-Original-To: cygwin@cygwin.com
Delivered-To: cygwin@cygwin.com
DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 019303857C40
Authentication-Results: sourceware.org;
 dmarc=none (p=none dis=none) header.from=towo.net
Authentication-Results: sourceware.org; spf=none smtp.mailfrom=towo.net
Subject: Re: Symlink issue?
To: cygwin@cygwin.com
References: <DM8PR09MB7095D974DB3B0E50CDB008FAA5C29@DM8PR09MB7095.namprd09.prod.outlook.com>
 <4438dd5c-3575-4c4a-2ca5-869c2c6e9373@cornell.edu>
From: Thomas Wolff <towo@towo.net>
Message-ID: <2effc267-c2c7-f2e9-e01b-5490f5f37e9e@towo.net>
Date: Sun, 22 Aug 2021 02:40:59 +0200
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101
 Thunderbird/78.13.0
MIME-Version: 1.0
In-Reply-To: <4438dd5c-3575-4c4a-2ca5-869c2c6e9373@cornell.edu>
X-Provags-ID: V03:K1:8HeI3BnXGwfnpsLnYX+7Q4TlF9mIc8emV2CHLtMD2Angx3HyqsW
 tO00Rt1rrcg8D4v0qo+ElPIRkDd1UEJzGe+iao6EodI0VScicCR9UgKXUJg2dscqrRmdqbc
 ro2fkftcUXuOPpLzFSvD/VS6XdPj9suk3ZS86Ya7GvD3F1pcxOx6wUU1XbggZPfMoQaiI8W
 uhrdoClIxBYG6tjmkalGg==
X-UI-Out-Filterresults: notjunk:1;V03:K0:yBoVJCkvGnc=:ng76rt+Q+wwUlmwhXg3pB2
 R7blhjPQkB63QTH3T6PuiE6zp/UgbpcMCWZGFTQOWTiOOBduZ6I2BY0g9BQpTUqQXdp8XhU6F
 djuSYkshZ+t1hQwcLT6BtcuEtzfiCBtchtd5+1DFyfrdLTRcQlbP+yj5wMxt5GS/aAZjSVoHO
 T3Dad1bGfS2Rof0JGhYkLXc4mSnDiTiPViDNZ7RAOnbf7fKT4NDP5kXZlaDufxY9AGhNTljfv
 XjBGsdrlKIrhiZm+mzvvcDD4lfJPYfBrglWakUnLe1vwxTuJanQ0cSi1Dx7SicijxY5xflisJ
 LrzAt9fA0lwpZdo1Ginw6DfX4+aLLm52l62Hi4NexziKDhDMDzqmrx/3+K0LLzfrmSwaNAWVL
 9J2T9Vle1M9GjurD0rtX+3DBcaK+RQPqye6Y8YgVzkdlLiNvGm8+5vckx+9l9+ueRRP3vQWnI
 0vOY+pVM2gU/HsDxuCjB9CyY7ptV4KCQqSphbfYcveMo6uVSkq6Vp+Pk2OXNPtRNk4kD2R/1D
 quKlwpM40J1YLHv3eFJ7pGB5CKb4ZCWRLGv4D98etOZGAFWhCwDtBiRCaMZeYeWNFTpGnwTP6
 GdR96fOGbHrfFOjnIVMSSHwRvC4Ecx0JYNZNSQlFIzHagSTfZ4V0PW9ZhPU7IV2fJOhHyQqVa
 07dnr2rxu6mlv13Qd+Mf2g1UbHQAOb+KatfLWhnVN3eJ0xBhjtSAmxu12KqiKG1sNFwsdVdxS
 rLaiL8zOeZf2076FznS1mjaeqcNSixJE/SCZewoT1Lez2EnRabDbhCncUw4ByZff49RvfKl4d
 9+i+ZwsZR0KrJY+vxCknFnN1zmsbZRFRfRAchCQ/0P/FR20D1dKw4qOXRiPIKaIrv5tMeWT
X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00, BODY_8BITS,
 KAM_DMARC_STATUS, KAM_LAZY_DOMAIN_SECURITY, NICE_REPLY_A, RCVD_IN_MSPIKE_H2,
 SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.4
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on
 server2.sourceware.org
X-BeenThere: cygwin@cygwin.com
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Unsubscribe: <https://cygwin.com/mailman/options/cygwin>,
 <mailto:cygwin-request@cygwin.com?subject=unsubscribe>
List-Archive: <https://cygwin.com/pipermail/cygwin/>
List-Post: <mailto:cygwin@cygwin.com>
List-Help: <mailto:cygwin-request@cygwin.com?subject=help>
List-Subscribe: <https://cygwin.com/mailman/listinfo/cygwin>,
 <mailto:cygwin-request@cygwin.com?subject=subscribe>
Content-Type: text/plain; charset="utf-8"; Format="flowed"
Errors-To: cygwin-bounces+archive-cygwin=delorie.com@cygwin.com
Sender: "Cygwin" <cygwin-bounces+archive-cygwin=delorie.com@cygwin.com>
Content-Transfer-Encoding: 8bit
X-MIME-Autoconverted: from base64 to 8bit by delorie.com id 17M0fHjt015005



Am 21.08.2021 um 23:59 schrieb Ken Brown via Cygwin:
> On 8/21/2021 4:15 PM, Lavrentiev, Anton (NIH/NLM/NCBI) [C] via Cygwin 
> wrote:
>> Hi,
>>
>> Please consider the following Cygwin session:
>>
>> $ cd ~
>> $ pwd
>> /home/user
>> $ touch file
>> $ ls file
>> file
>> $ cygpath -w ~
>> C:\cygwin64\home\user
>> $ mkdir /cygdrive/g/cygwin/dir
>> $ ln -s /cygdrive/g/cygwin/dir ./dir
>> $ ls -l dir
>> ... dir -> /cygdrive/g/cygwin/dir/
>> $ cd dir
>> $ pwd
>> /home/user/dir
>> $ cygpath -w `pwd`
>> G:\cygwin\dir
>> $ ls -l ../fil<TAB>  (this expands to ../file but when Enter is hit):
>> ls: cannot access '../file': No such file or directory
>>
>> so basically "file" is not accessible with the relative dot-dot link,
>> even though somehow readline (bash completion) can figure it out and 
>> suggest
>> the correct completion.
>>
>> Is this a Cygwin bug?
>
> I don't think so.  I see identical behavior on Linux (using /tmp/dir 
> instead of /cygdrive/g/cygwin/dir).
>
> Pathname resolution proceeds from left to right, with symlinks 
> expanded as they are encountered.  See "Pathname resolution" in
>
> https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html
>
> When the CWD is /home/user/dir, the resolution of ../file goes like this:
>
> ../file = /home/user/dir/../file
>         = /cygdrive/g/cygwin/dir/../file
>         = /cygdrive/g/cygwin/file,
>
> which doesn't exist.
>
> I don't know why bash completion suggests something different.  My 
> guess (and it's only a guess) is that bash completion takes a shortcut 
> for performance reasons.
The symlink/.. confusion is a dreadful trap since Unix times.
Unfortunately, bash completion does not consider path resolution, so if 
any, it's a bash completion bug.
Thomas
>
> Ken
>


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