NAME
light – a program to control backlight controllers
SYNOPSIS
light [OPTIONS] [VALUE]
DESCRIPTION
light is a program to control backlight display and keyboard controllers under GNU/Linux.
-
Operates independently of X (X-Window)
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Can automatically figure out the best controller to use, making full use of the underlying hardware
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Supports a minimum cap on the brightness value, as some controllers set the display to be pitch black at a vaĺue of 0 (or higher)
COMMANDS
The following unique commands are supported:
- -H, -h
-
Show help text and exit
- -V
-
Show program version and exit
- -L
-
List available devices
- -A
-
Increase brightness by value
- -U
-
Decrease brightness by value
- -S
-
Set brightness to value
- -G
-
Get brightness, default
- -N
-
Set minimum brightness to value
- -P
-
Get minimum brightness
- -O
-
Save current brightness
- -I
-
Restore previously saved brightness
OPTIONS
The behavior of the above commands can be modified using these options:
- -r
-
Interpret input and output values in raw mode
- -s PATH
-
Specify device target path. Use -L to list available devices
- -v LEVEL
-
Set verbosity level, by default light only outputs read values:
- 0:
-
Read values
- 1:
-
Read values, Errors
- 2:
-
Read values, Errors, Warnings
- 3:
-
Read values, Errors, Warnings, Notices
FILES
When run in its classic SUID root mode light caches settings and current brightness in /etc/light. In its non-privileged mode of operation the ~/.cache/light directory is used instead.
AUTHORS
Copyright © 2012-2018 Fredrik Haikarainen
This is free software, see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE