1LIGHT(1)                    User's Reference Manual                   LIGHT(1)
2

NAME

4     light — a program to control backlight controllers
5

SYNOPSIS

7     light [OPTIONS] [VALUE]
8

DESCRIPTION

10     light is a program to control backlight display and keyboard controllers
11     under GNU/Linux.
12
13     ·   Operates independently of X (X-Window)
14     ·   Can automatically figure out the best controller to use, making full
15         use of the underlying hardware
16     ·   Supports a minimum cap on the brightness value, as some controllers
17         set the display to be pitch black at a vaĺue of 0 (or higher)
18

COMMANDS

20     The following unique commands are supported:
21
22     -H, -h  Show help text and exit
23
24     -V      Show program version and exit
25
26     -L      List available devices
27
28     -A      Increase brightness by value
29
30     -U      Decrease brightness by value
31
32     -S      Set brightness to value
33
34     -G      Get brightness, default
35
36     -N      Set minimum brightness to value
37
38     -P      Get minimum brightness
39
40     -O      Save current brightness
41
42     -I      Restore previously saved brightness
43

OPTIONS

45     The behavior of the above commands can be modified using these options:
46
47     -r      Interpret input and output values in raw mode
48
49     -s PATH
50             Specify device target path.  Use -L to list available devices
51
52     -v LEVEL
53             Set verbosity level, by default light only outputs read values:
54
55             0:  Read values
56             1:  Read values, Errors
57             2:  Read values, Errors, Warnings
58             3:  Read values, Errors, Warnings, Notices
59

FILES

61     When run in its classic SUID root mode light caches settings and current
62     brightness in /etc/light.  In its non-privileged mode of operation the
63     ~/.cache/light directory is used instead.
64

AUTHORS

66     Copyright © 2012-2018 Fredrik Haikarainen
67
68     This is free software, see the source for copying conditions.  There is
69     NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
70     PURPOSE
71
72GNU/Linux                       August 4, 2018                       GNU/Linux
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