blight(1)
blight - A desktop independent backlight utility
blight [options...] [command] [args]
-h, --help Show help message and quit.
-d, --device Specify which device to act on. If not specified, chooses a sane default. Format is /, e.g. "backlight/intel_backlight"
set Set a brightness value. There are several accepted formats for value with different meanings. See the VALUE FORMATS section below.
get [value] Gets and prints a value. If no value is specified, get the brightness value for the device. value may be:
_default-device_ shows which device is acted on by default.
_brightness_ shows the current brightness value in device units.
_max-brightness_ shows the maximum brightness value in device units.toggle [value] Toggle through the available brightness values. If an absolute value is provided, switch between that value and 0 (off). Otherwise, specify a relative value to change the order of the toggle values.
The set command takes values in several formats that change it's behavior. For any value but an Absolute Value, if the requested value would turn the backlight completely off, the value is clamped to the active range of the device. If the requested value is greater than max-brightness it will also be clamped. Values may be floating point.
n (Absolute Value) Set the absolute brightness to this value using the internal units of of the device. If value is greater than max-brightness, it will be clamped.
n% (Absolute Percentage) Set the brightness of the device to the given percent of the maximum brightness value.
+n, -n (Linear Relative Value) Add or subtract to the current brightness value in the internal units of the device. If the result is greater than max-brightness it will be clamped.
+n%, -n% (Relative Percentage) Add or subtract to the current brightness value in units of percentage of the maximum brightness.
xn, /n (Geometric Relative Value) Multiply or divide the current brightness value. Multiplying by a factor greater than one or dividing by a factor less than one is guaranteed to increase the brightness of the device by at least one unit if possible, and similar for decreasing the brightness.
+/n, -/n (Stepped Linear Value) Step the brightness up or down to the next level in a set number of divisions of the maximum brightness. For example, '+/10' for a backlight of maximum brightness 100 would change brightness 11 to 20, and '-/10' from 11 to 10. '-/10' again from 10 would reduce to 1 if 0 would turn the backlight off. A value n has exactly n divisions, or n+1 levels, including the lowest level.
+//n, -//n (Stepped Geometric Value) Step the brightness up or down to the next level in a set number of logarithmic divisions of the maximum brightness. A value n is guaranteed to have n+1 levels, separated by at least one device unit.
Maintained by Ronan Pigott rpigott@berkeley.edu