LUMONCTL(1)

NAME ¶

lumonctl - luminance control for displays with luminance curves

SYNOPSIS ¶

lumonctl [-c path] [-o offset] [-t luminance]

DESCRIPTION ¶

lumonctl adjusts the luminance of your connected displays. As different displays might have a different luminance at the same setting, lumonctl allows you to alter the luminance curves. The input values for this program will here be called "target luminances". lumonctl will map these values to "actual luminances" before applying them.

The options are as follows:

-c path

Override the path for the configuration file. (Default: /etc/lumoncfg.conf)

-o offset

Increase/decrease the target luminance by the given offset. If your luminance curve is too flat or not bijective, this might not work. The reason for this is that the current target luminance is deduced from the current actual luminance reported by the monitor that is detected first.

-t luminance

Set the target luminance to the given value.

-V

Print the version information and exit.

The luminance curves can be set using the configuration file. The format used for the configuration file is scfg. For each display, lumonctl will try to match on each display directive and pick the first one that matches. A display directive looks like this:

display <manufacturer> <model> <serial number> {
	<target luminance> <actual luminance>
	...
}

You can find out the manufacturer id, model and serial number of your display using ddcutil. To match on any value, use "_". This means that you can define a generic fallback like this:

display _ _ _ {}

Such a fallback should be placed last in the configuration file. Otherwise, every display directive after that will be effectively ignored.

If no display directive matches, the luminance of that display will not be adjusted.

Each subdirective in a display directive is a pair of the target luminance and an actual luminance. If a target value inbetween two points is requested, its value will be linearly interpolated. The value range for the target luminance is 0 to 100 (inclusive). The value range for the actual luminance is 0 to 65535 (inclusive) in theory. Practically, its maximum value is usually 100 as well. Each curve implicitly contains the points (0, 0) and (100, 100). The actual luminances of these two points can be overridden by explicitly specifiying these two points.

SEE ALSO ¶

ddcutil(1)

EXIT STATUS ¶

lumonctl exits with 0 on success, and with 1 if an error occured.

AUTHORS ¶

Created and maintained by Hannes Braun <hannes@hannesbraun.net>. Up-to-date sources can be found at https://git.sr.ht/~hannes/lumonctl. Bugs and patches can be submitted by email to ~hannes/public-inbox@lists.sr.ht.