How to use chmod in ~/.bashrc

Question

I would like to change the permission of a file in the /sys directory but the permissions keep reseting after reboot. I tried to add a chmod in the ~/.bashrc so the permission would change upon booting, but I get an error (operation not permited) in terminal. What would be the right way to do this ? Does the ~/.bashrc get executed as root ?

This is my command in ~/.bashrc

chmod 664 /sys/class/backlight/intel_backlight/brightness

And this is the error I get:

chmod: changing permissions of ‘/sys/class/backlight/intel_backlight/brightness’
: Operation not permitted

Answer 1

~/.bashrc is run as the user when the user logs in. It is not run on boot.

If you want to change the permissions on a file, you need to have permission to do so. The message is telling you that you don't have permission -- only root can do so.

The simplest way to do something custom on boot-up is to stick it in the file /etc/rc.local . This script is run by root after booting up (so on every reboot), so you can just stick your chmod command in there.