Changing screen Brightness with a script

Question

As you may know, screen brightness drains battery, that's why it is considered a big problem for laptops (at least for me).

I can change the screen brightness but every time ubuntu boots up I will have to change it again.

Luckily, you can write a script that does that for you. However, when the laptop is plugged in I do want the maximum brightness; which means I will have to do that by myself every time I plug in the laptop.

Is there a script that detect if the laptop is charging or not and sets the brightness level accordingly?

also see How to get a notification when computer is not charging? — αғsнιη, Nov 13 '14 at 20:21

score 1 · Accepted Answer · answered Nov 13 '14 at 19:43

1

On my laptop I can check the contents of the file /sys/class/power_supply/C1BC/online: if the laptop is plugged in this file contains 1, otherwise it contains 0.

For example,

if [ "1" = "`cat /sys/class/power_supply/C1BC/online`" ]; then
  echo "Laptop is charging/plugged"
else
  echo "Laptop is discharging/unplugged"
fi

Note. As confirmed by the OP, the C1BC part is system dependent.

answered Nov 13 '14 at 19:43

edwin

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1

Thanks, it worked. Mine was ACAD though. – Mohammad Nov 13 '14 at 19:46

score 0 · Answer 2 · answered Dec 02 '14 at 09:55

Try this

To adjust brightness in xubuntu or ubuntu Open a terminal window, and execute this command to edit /etc/rc.local:

sudo nano /etc/rc.local

Add this before the last line “exit 0″:

echo xx > /sys/class/backlight/acpi_video0/brightness

Where number xx is the value of your screen brightness of your choice.

The maximum value for brightness can be found with:

cat /sys/class/backlight/acpi_video0/max_brightness

Changing screen Brightness with a script

2 Answers2