"permission denied" issues when removing files/folders created by cygwin

"permission denied" issues when removing files/folders created by cygwin

[Roger Pack]

As a note, after using cygwin to build some libraries (worked well,
thanks team!) when trying to delete a folder via windows explorer, I
got the message  "Destination folder access denied, you need to
confirm this action"  (followed by a UAC prompt) and also
"Delete folder, Invalid MS-DOS function"

It appears the problem lies with creating a file named "NUL" windows
utilities just don't know how to deal with it (you can recreate it by
creating a folder, then from cygwin bash $ touch NUL) then try and
remove the folder with windows explorer.

I would not have expected cygwin to allow itself the privilege of
creating files that are unremovable by windows explorer, but I just
thought I'd throw it out there.

Cheers!
-roger-

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

Re: "permission denied" issues when removing files/folders created by cygwin

[Michael Enright]

On Tue, Sep 1, 2015 at 12:48 PM, Roger Pack  wrote:
> It appears the problem lies with creating a file named "NUL" windows
> utilities just don't know how to deal with it (you can recreate it by
> creating a folder, then from cygwin bash $ touch NUL) then try and
> remove the folder with windows explorer.

The utilities "know" how to deal with it, given their design:
http://blogs.msdn.com/b/oldnewthing/archive/2003/10/22/55388.aspx

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

Re: "permission denied" issues when removing files/folders created by cygwin

[Corinna Vinschen]

[-- Attachment #1: Type: text/plain, Size: 1117 bytes --]

On Sep  1 13:05, Michael Enright wrote:
> On Tue, Sep 1, 2015 at 12:48 PM, Roger Pack  wrote:
> > It appears the problem lies with creating a file named "NUL" windows
> > utilities just don't know how to deal with it (you can recreate it by
> > creating a folder, then from cygwin bash $ touch NUL) then try and
> > remove the folder with windows explorer.
> 
> The utilities "know" how to deal with it, given their design:
> http://blogs.msdn.com/b/oldnewthing/archive/2003/10/22/55388.aspx

And then there's

https://cygwin.com/cygwin-ug-net/using-specialnames.html#pathnames-dosdevices

You can create and delete those files even in CMD, btw.  You just have
to use the long pathname prefix "\\?\", e.g.:

  bash$ cmd /c 'echo foo > \\?\c:\cygwin64\home\corinna\nul'
  bash$ ls -l nul
  -rwxr-xr-x 1 corinna vinschen 6 Sep  1 22:30 nul

delete with

  bash$ rm nul

or

  bash$ cmd /c 'del \\?\c:\cygwin64\home\corinna\nul'


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

[-- Attachment #2: Type: application/pgp-signature, Size: 819 bytes --]

Re: "permission denied" issues when removing files/folders created by cygwin

[Roger Pack]

On 9/1/15, Corinna Vinschen <corinna-cygwin@cygwin.com> wrote:
> On Sep  1 13:05, Michael Enright wrote:
>> On Tue, Sep 1, 2015 at 12:48 PM, Roger Pack  wrote:
>> > It appears the problem lies with creating a file named "NUL" windows
>> > utilities just don't know how to deal with it (you can recreate it by
>> > creating a folder, then from cygwin bash $ touch NUL) then try and
>> > remove the folder with windows explorer.
>>
>> The utilities "know" how to deal with it, given their design:
>> http://blogs.msdn.com/b/oldnewthing/archive/2003/10/22/55388.aspx
>
> And then there's
>
> https://cygwin.com/cygwin-ug-net/using-specialnames.html#pathnames-dosdevices
>
> You can create and delete those files even in CMD, btw.  You just have
> to use the long pathname prefix "\\?\", e.g.:
>
>   bash$ cmd /c 'echo foo > \\?\c:\cygwin64\home\corinna\nul'
>   bash$ ls -l nul
>   -rwxr-xr-x 1 corinna vinschen 6 Sep  1 22:30 nul
>
> delete with
>
>   bash$ rm nul
>
> or
>
>   bash$ cmd /c 'del \\?\c:\cygwin64\home\corinna\nul'

Yeah this works.  Windows explorer is not as clever unfortunately, so
lay users would find trouble here (my particular case is they install
a local copy of cygwin which cross compile's something for them--no
knowledge of cygwin required--but then suddenly they find they cannot
remove folders through any easy means...)
Cheers!

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

Re: "permission denied" issues when removing files/folders created by cygwin

[Achim Gratz]

Roger Pack <rogerdpack2 <at> gmail.com> writes:
> It appears the problem lies with creating a file named "NUL" windows
> utilities just don't know how to deal with it (you can recreate it by
> creating a folder, then from cygwin bash $ touch NUL) then try and
> remove the folder with windows explorer.

That is likely a bug in the build system of whatever you were trying to
build, I can't think of any reason why under Cygwin it wouldn't use
/dev/null instead of NUL (that's a device name under Windows for
compatibility with DOS).


Regards,
Achim.


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