Issue
I want to write to a protected file as root at startup. Just using
echo "disable" > /sys/firmware/acpi/interrupts/gpe6F
as a user (or even with sudo in front) does of course not work. So I looked around, but the suggested alternatives don't work either, e.g. the tee trick does not work:
echo "disable" | sudo tee /sys/firmware/acpi/interrupts/gpe6f
tee: /sys/firmware/acpi/interrupts/gpe6f: Permission denied
and neither does this:
sudo sh -c "echo \"disable\" > /sys/firmware/acpi/interrupts/gpe6f"
sh: 1: cannot create /sys/firmware/acpi/interrupts/gpe6f: Permission denied
I can only succesfully write to that file when I change to root:
sudo su
echo "disable" > /sys/firmware/acpi/interrupts/gpe6F
This one works. However, I want to do this at system startup via /etc/rc.local. That file should be executed as root already. So I put the above mentioned commands (without sudo) in /etc/rc.local and ran sudo /etc/rc.local to test it and got "Permission denied" errors. What am I missing here?
In case you are interested in my motivation to do this: [solved] ASRock skylake flooding syslog with gpe6F
Solution
As tripleee and ESYSCODER have pointed out: Changing gpe6f to gpe6F fixed the problem for me. What a stupid little mistake.
Thanks! :)
Answered By - mad