permission 600

[Tatsuro MATSUOKA]

> ----- Original Message ----- 
> From: "Tatsuro MATSUOKA" 
> To: "Thomas Wolff" ; "cygwin
> Date: 2022/01/10 月 20:10
> Subject: Re: permission 600
> 
> 
> > ----- Original Message -----
> > From: "Thomas Wolff" 
> > To: "cygwin@
> > Date: 2022/01/10 月 08:28
> > Subject: Re: permission 600
> > 
> > 
> > 
> > Am 10.01.2022 um 00:13 schrieb Tatsuro MATSUOKA:
> > >> ----- Original Message -----
> > >>
> > >> From: "Eliot Moss"
> > >> To: "cygwin
> > >> Date: 2022/01/09 日 20:26
> > >> Subject: Re: permission 600
> > >>
> > >>
> > >> On 1/9/2022 6:11 AM, Tatsuro MATSUOKA wrote:
> > >>>> ----- Original Message -----
> > >>>>
> > >>>> From: "Thomas Wolff"
> > >>>> Date: 2022/01/09 日 17:51
> > >>>> Subject: Re: permission 600
> > >>>> Am 09.01.2022 um 07:10 schrieb Tatsuro MATSUOKA:
> > >>>>>> ----- Original Message -----
> > >>>>>>
> > >>>>>> From: "Marco Atzeri"
> > >>>>>> To: "cygwin> Date: 2022/01/09 日 14:39
> > >>>>>> Subject: Re: permission 600
> > >>>>>>
> > >>>>>>
> > >>>>>> On 09.01.2022 06:28, Tatsuro MATSUOKA wrote:
> > >>>>>>> $ echo aaa > test.txt
> > >>>>>>> $ ls -l  test.txt
> > >>>>>>> -rw-r--r-- 1 user user 4 Jan  9 14:07 test.txt
> > >>>>>>> $ chmod 600 test.txt
> > >>>>>>> $ ls -l test.txt
> > >>>>>>> -rw-r--r-- 1 user user 4 Jan  9 14:07 test.txt
> > >>>>>> it works for me
> > >>>>>>
> > >>>>>> $ ls -l test.txt
> > >>>>>> -rw-r--r-- 1 Marco Kein 4 Jan  9 06:35 test.txt
> > >>>>>>
> > >>>>>> $ chmod 600 test.txt
> > >>>>>>
> > >>>>>> $ ls -l test.txt
> > >>>>>> -rw------- 1 Marco Kein 4 Jan  9 06:35 test.txt
> > >>>>>>
> > >>>>>> I suspect that having user and group called same
> > >>>>>> is the clue
> > >>>>>>
> > >>>>> Ah! Thanks!
> > >>>>>
> > >>>>> Tatsuro
> > >>>> Did you verify it by using different names?
> > >>>> It can hardly be an explanation by POSIX means. If so, it must be some
> > >>>> weird consequence of Windows-specific stuff. Maybe a workaround could be
> > >>>> found for cygwin?
> > >>> I made another windows account and sign in PC with different user name.
> > >>> But result for chmod 600 gave the same results.
> > >>> I found the workaround for jupyter by readind the code of "paths.py" in jupyter.
> > >> You can find the underlying Window permissions using icacls.  Cygwin
> > >> has to set up some funky work-arounds to model some of the POSIX
> > >> permissions - the two models are substantially different.  Sometimes
> > >> clearing back to some nominal Windows permissions and applying
> > >> chmod again helps.  "setfacl -b" can help clear out permissions,
> > >> etc.  Don't forget that permissions can be inherited from the
> > >> containing directory as well.
> > >>
> > >> Other people may be able to offer more specific guidance, especially
> > >> if you post the output of icacls.
> > >>
> > >> Best - Eliot Moss
> > >>
> > > Because my C drive is not enough, I installed cygwin into USB drive and make home directory on it.
> > > chmod issue are story files on the usb drive.
> > > On files on C drive, chmod 600 works as expected.
> > >
> > > My workround for jupyter changed :
> > > export JUPYTER_ALLOW_INSECURE_WRITES=true
> > > =>
> > > export JUPYTER_RUNTIME_DIR=/cygdrive/c/Users/user/AppData/Local/Temp
> > > (/cygdrive/c/Users/user/AppData/Local/Temp "tmp" environmental variable value in my current environment.)
> > >
> > > For another usb drive, chmod works as expected.
> > > chmod does not work  => FAT32
> > > chmod works => NTFS
> > I was about to ask...
> > > I back up all files to the external HDD and  format FAT32 drive to NTFS drive and back them.
> > You can actually convert a USB drive to NTFS without copying files and 
> > reformatting,
> > using $SYSTEMROOT/System32/convert
> > 
> I will try after backup. 
> Thanks!
> 
> Tatsuro

I would like to clean up USB drive so that I format the drive and come back necesary file images were back.
So I did not use convert.
But thanks for your kindness.
After formatting USB drive in NTFS format, chmod 600 works as expected.
and 
$ python3.8 -m jupyter lab
now works without any patch work.

Thanks!

Tatsuro