Permissions change concern

Corinna Vinschen
Tue Apr 19 07:58:00 GMT 2016

On Apr 18 16:33, Eliot Moss wrote:
> On 4/18/2016 2:55 PM, Corinna Vinschen wrote:
> >On Apr 18 09:14, Eliot Moss wrote:
> >>On 4/18/2016 6:18 AM, Corinna Vinschen wrote:
> >>>On Apr 16 22:17, Eliot Moss wrote:
> >Your example looks like 775.  But even then, the actual permissions
> >depend on the mode bits given to the open(2) call, which are usually 666
> >in this echo example.  The resulting perms should be 664.
> Thank you -- I am convinced and agree, and that is what I get.
> >Cygwin also takes the umask value into account if the newly created
> >ACL only contains default POSIX permissions.  That's not quite correct
> >in terms of POSIX 1003.1e draft 17, but in contrast to Linux, Windows
> >directory ACLs practically always have default ACEs, so we have to
> >compromise a bit, or umask just has no effect at all.  I fixed a
> >problem with the permssion handling in case a mask value is present, but
> >that shouldn't matter in your case.
> >
> >>2) If the directory has g+s set (visible from -s- in the flags shown
> >>    by getfacl), the directory's group is Cygwin, and my primary group is moss,
> >>    then the file gets created with group moss, not group Cygwin (which is
> >>    what g+s is supposed to mean, right?)
> >
> >There was still another bug in the same code snippet which disallowed to
> >set the special POSIX bits S_ISVTX/S_ISGID/S_ISUID under some
> >circumstances, but apart from that what you describe works for me if the
> >bit is set in the parent dir and the parent dir inherits entries.
> >
> >But this only works if you create the file with a Cygwin executable and
> >the parent dir has inheritable ACEs.
> >
> >I uploaded another snapshot to to make
> >sure the aforementioned bug can be tested as well.  Please check the
> >latest snapshot again.
> >
> >However, if the s bit (aka S_ISGID) doesn't quite work as desired, I
> >have to defer any solution (if possible) until after my vaca.
> The g+s bit now works as I hoped/expected. Thanks!     E

Thanks for your feedback!


Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: not available
URL: <>

More information about the Cygwin mailing list