Trying to change the screen brightness of my computer and having failed by conventional methods, I found out that one way is to simply change the value of /sys/class/backlight/acpi_video0/brightness.
But when I issue
cd /sys/class/backlight/acpi_video0/
sudo nano brightness
nano says I have no permission to write to ./.brightness.swp, which is weird because neither does ls -la list such file, nor is brightness a symlink. And although I can still write to brightness file (so this is not a duplicate of that other question), changing it takes no effect on screen brightness.
Can you help me out?
