On 2021-08-21 18:40, Thomas Wolff wrote:
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.
Try using cd -P (via alias?) which may resolve physically if it works.
Otherwise enjoy the quirks of cd via symlinks and .. resolution after.
--
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
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