Permission denied when opening /sys/class/gpio/export

[S4mw1s3]

Hi,

I'm running Linux 5.15.16 and I get a Permission denied: '/sys/class/gpio/export' error when instantiating GPIOPin.
I think the FMODE should not be w+ but simply w:

root@sam:~# stat /sys/class/gpio/export
  File: /sys/class/gpio/export
  Size: 4096            Blocks: 0          IO Block: 4096   regular file
Device: 11h/17d Inode: 2618        Links: 1
Access: (0200/--w-------)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2022-01-18 11:35:45.430000000 +0000
Modify: 2022-01-18 11:35:45.430000000 +0000
Change: 2022-01-18 11:35:45.430000000 +0000
root@sam:~#
root@sam:~#
root@sam:~# python3
Python 3.10.2 (main, Jan 13 2022, 19:06:22) [GCC 11.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import gpio
>>> gpio.GPIOPin(10)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.10/site-packages/gpio/__init__.py", line 49, in __init__
    with open(GPIO_EXPORT, FMODE) as f:
PermissionError: [Errno 13] Permission denied: '/sys/class/gpio/export'
>>>
>>>
>>>
>>>
>>> print(gpio.FMODE)
w+
>>>
>>>
>>> print(gpio.GPIO_EXPORT)
/sys/class/gpio/export
>>>
>>>
>>>
>>>
>>> with open(gpio.GPIO_EXPORT, "w+") as f:
...   print("OK")
...
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
PermissionError: [Errno 13] Permission denied: '/sys/class/gpio/export'
>>>
>>>
>>>
>>> with open(gpio.GPIO_EXPORT, "w") as f:
...   print("OK")
...
OK
>>>

[nazzak]

Yes, absolutely, export/unexport are not normal file. We should use "w"