Re: chmod g+s ineffective

[Norton Allen <allen@huarp.harvard.edu>]

On 6/29/2022 7:39 AM, Andrey Repin wrote:
> Greetings, Norton Allen!
>
>> On one machine I have, chmod g+s fails to set the sticky bit. The command
>> does not return any error, but ls -l continues to show the bit not set.
>>      $ mkdir foo
>>      $ chgrp flight foo
>>      $ chmod g+ws foo
>>      $ ls -ld foo
>>      drwxrwxr-x+ 1 nort flight 0 Jun 29 06:50 foo
> ----------------^
>
> $ getfacl foo

I will collect this shortly, but IIRC, getfacl showed it was not set. I 
did see it set there under 'flags' on the system that works.


>
>> I ran strace, and it looks like the correct system call parameter is getting passed.
>> I am curious as to how the sticky bit is implemented.
> First see if it was set or not.
>
>> It isn't obvious what underlying Windows functionality (if any) is applied.
> It does. But the big question is, where do you try to do that.
> If this is inside Cygwin installation root, then things could work more or
> less POSIX'y. If this is outside Cygwin root (f.e. in your system profile), it
> may or may not work completely, depends how did you mount /cygdrive prefix.

I will confirm (shortly), but I'm pretty sure these tests were done 
under vanilla /home (so c:\cygwin64\home)


>
>> Ah, just checked on a system where this works, and creating a file in the
>> directory from the
>> command shell does not set the group, so presumably this functionality is
>> all within cygwin. That works for my application, except when it doesn't.
>> Any suggestions on what I should look for?
> Look if you could avoid using +s. Isn't DACL enough?

Am I correct that DACL is not available unless I am on a domain? This is 
for a field computer, so connection to a domain is generally more 
problematic than helpful.