Now I can change it by Fn
+ arrow right
but now I need to do it via my shell script
9 Answers
adding to what Michał Šrajer says in some cases the brightness may be controlled from /sys/class/backlight/acpi_video0/brightness
as is the case with my dell vostro 3400 and my the brightness range is 0-15. You may have to look for other folder in /sys/class
if the same path as mine doesnot exit.
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See my comment on Michał Šrajer's post below for a way to alias this for easy use.– floer32Nov 2, 2012 at 12:24
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How to change it? is not by
sudo nano /sys/class/backlight/acpi_video0/brightness
... Dec 27, 2017 at 14:05 -
3for me it was via
sudo vim /sys/class/backlight/intel_backlight/brightness
– DaraJAug 21, 2018 at 22:11 -
Also, don't forget that instead of
vim
ing ornano
ing to edit the file, you can simplyecho 15 > /sys/class/backlight/intel_backlight/brightness
May 17, 2020 at 3:49
In your script you can send the equivalent keystrokes that correspond to Fn+Right Arrow and Fn+Left Arrow i.e. Brightness Up and Down respectively
Install xdotool
from the Software Center
Then in your script to increase brightness:
xdotool key XF86MonBrightnessUp
To decrease Brightness
xdotool key XF86MonBrightnessDown
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So I was able to do this in the terminal in Ubuntu 15.04 with both the MATE and Unity desktops. However, when I bind this to any key combination it does not work. Apr 18, 2015 at 1:03
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This still works (for me, at least) for XFCE on 18.04. Yet it doesn't allow to set to a fixed value, only steps up or down. Jun 14, 2018 at 20:32
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I run
lxqt
on lubuntu 20_04, what should I write forkey
?xdotool key XF86MonBrightnessDown
does not work.– TimoMay 24, 2021 at 18:23
You could install xbacklight package $sudo apt-get install xbacklight
and then if you want to increase the brightness level, type $xbacklight -inc <level in a range of 10 - 100>
and vice versa: $xbacklight -dec <level in a range of 10 - 100>
.
Read xbacklight --help
to see more options.
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my notebook keyboard is broken, the external usb one has no key for that. the -dec option works, the -inc dont! but the -set does! so I will just create a simple script, thx!!! Jun 3, 2017 at 3:31
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call:
sudo su -c 'echo 30 > /proc/acpi/video/VID/LCD0/brightness'
The path may be different in your system. To list all available call:
find /proc/acpi/video -name 'brightness'
To see possible values for each, just cat the file:
cat /proc/acpi/video/VID/LCD0/brightnes
Install xbacklight it is very light and useful.
sudo apt-get install xbacklight
Then use xbacklight -set 60 where number can varry from 0 to 100.
Ubuntu's default desktop environment, Unity, has set of dbus
methods that allow setting/getting brightness without need for sudo
access.
Note well, that for this to work, one will need to have DISPLAY=:0
variable declared in the script.
Personally, I use qdbus
application , with all the appropriate interface and method names combined into a nice function and store it in .bashrc
unityBrightness()
{ # change brightness in Unity/ Gnome
qdbus org.gnome.SettingsDaemon.Power\
/org/gnome/SettingsDaemon/Power\
org.gnome.SettingsDaemon.Power.Screen.SetPercentage "$1"
}
Usage of this function would be like :
unityBrightness 50
, where 50
is the percentage.
Equivalent dbus-send
command would be
dbus-send --session --print-reply\
--dest=org.gnome.SettingsDaemon.Power\
/org/gnome/SettingsDaemon/Power \
org.gnome.SettingsDaemon.Power.Screen.SetPercentage uint32:"$1"
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Getting
Error org.freedesktop.DBus.Error.UnknownMethod: No such method “SetPercentage”
:(– RohlikSep 29, 2022 at 16:52
If you are using laptop.
You can use this command: sudo setpci -s 00:02.0 F4.B=xx
Which xx
is the brightness in hex ranging from 0 (brightest) to FF (no brightness at all). I Use E0
when working on battery.
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@enzotib : It works fine with me using 11.04. And I think it is only for a laptop. Aug 7, 2011 at 20:55
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This is the only one that works for me on a Gateway / Packard Bell. Feb 20, 2016 at 22:41
Here is a little utility to set brightness from terminal: linux-brightness-binary
Then you can set brightness like this: sudo bright 5
or sudo bright 0
0-15 works for me on Asus UX50V Laptop running Debian 7
On Ubuntu trusty 14.04, this command works fine
sudo su -c 'echo 12 > /sys/class/backlight/acpi_video0/brightness'
You can change the value 12 to any value from 0 to 20
Thanks @Michał Šrajer and @sagarchalise