This question is originally posted on rsapberrypi stackexchange. Since it is not so raspberrypi-related, I think it's better to post here.
I found a strange thing while playing with pi3B.
I want to create a file in
/sys/class/gpio (just poking arround, no specific reason) but I get a Permission Denied. Below is some information.
pi@raspberrypi:/sys/class/gpio $ groups pi adm dialout cdrom sudo audio video plugdev games users input netdev gpio i2c spi pi@raspberrypi:/sys/class/gpio $ ls -ld . drwxrwx--- 2 root gpio 0 May 6 00:28 . pi@raspberrypi:/sys/class/gpio $ touch somefile touch: cannot touch 'somefile': Permission denied
As you can see, I am in group gpio and the group has the write permission of directory
So the question is Why I can't create new files in
/sys/class/gpio even if the group I am a part of has the permission.
I tried relogin and reboot after add the pi user to group gpio and that's several days ago.
OS: raspbian stretch