Re: permission 600

[Thomas Wolff <towo@towo.net>]

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