changing brightness on 2008 imac on reborn os

xorg-xbacklight or brightnessctl don't work for this imac. on the laptop that was my goto fix before.

on the 2008 imac you gotta use sysfs interface

• check the available interfaces

ls ~/sys/class/backlight/

in my case it was radeon_bl0

sudo vim ~/sys/class/backlight/brightness

it says 255 jeez. im going to lower it to 70

chmod and chown the brightness file so you don't need sudo to edit the file then:

# Increase brightness
bindsym XF86MonBrightnessUp exec --no-startup-id sh -c 'echo $(($(cat /sys/class/backlight/radeon_bl0/brightness) + 10)) > /sys/class/backlight/radeon_bl0/brightness'

# Decrease brightness
bindsym XF86MonBrightnessDown exec --no-startup-id sh -c 'echo $(($(cat /sys/class/backlight/radeon_bl0/brightness) - 10)) > /sys/class/backlight/radeon_bl0/brightness'