Re: [trinity-users] to adjust the brightness of the screen

On 07/11/2019 04:35 PM, Mike Bird wrote: You can also check for an interface through, e.g. /sys/class/backlight/acpi_video0/ or e.g. /sys/class/backlight/intel/ within each directory you should have a sysfs structure for 'brightness' and 'max_brightness' For example, you can check the current and max brightness with: cat /sys/class/backlight/acpi_video0/brightness cat /sys/class/backlight/acpi_video0/max_brightness To set, you must be root (or EUID 0 with sudo, etc..) and echo 5 > /sys/class/backlight/acpi_video0/brightness I just use a script that reads the last set value from /usr/local/share/brightness on startup (set in ~/.kde/Autostart) and use an alias to the script `bl` that then allows adjustment with `bl +` or `bl -` or `bl value`. You can also end up in the circumstance where your F11/F12 are actually setting the values in: /sys/class/backlight/acpi_video0/brightness but your video driver (e.g. Nvidia, etc..) is using /sys/class/backlight/nvidiabl/brightness In that case you can use a similar script at startup to background a watch with inotifywait that watches .../acpi_video0/brightness and then sets .../nvidiabl/brightness whenever it changes. Bottom line, few desktops actually have interfaces to manufacturer keyboard mappings for specific hardware hotkeys. (plasma -- hiss, seems to do better than others) Some distros used to provide specific packages, and KDE used to have for example Sony hotkeys package and a few others. But that is they type of package that must be maintained with every new crop of laptops. (e.g. Sony hotkeys doesn't mean a whole lot anymore...) So mapping your own key to the feature you use to control brightness is probably the only reliable way to make sure they work. -- David C. Rankin, J.D.,P.E.