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I have been trying to get my laptop's screen brightness to default to a low setting, and for my keyboard light to be off when I start my computer.

I have these two commands that work when I execute them at the command line:

xbacklight -set 7
echo 0 | sudo tee /sys/class/leds/asus::kbd_backlight/brightness

I put them in my /etc/rc.local file, like so:

#!/bin/sh -e
# ...
# By default this script does nothing.
echo 0 | tee /sys/class/leds/asus::kbd_backlight/brightness
xbacklight -set 7
exit 0

However, neither command executes. (I was told that the sudo was not needed in the second command when placed in /etc/rc.local)

There was another question asking the same thing about rc.local, but I tried to also include my commands using the Startup Applications GUI interface. That also did not work, so I think the problem might go beyond just the rc.local file. Other default startup commands in the list seem to start, so far as I can tell.

Why am I unable to get any custom command line to execute when I startup?

New: After some experimentation, it seems like the commands I put in /etc/rc.local might be getting executed before the login screen. So, my login screen has the screen appropriately dimmed. However, then when I login, my screen goes to maximum brightness. So it seems like perhaps there is some other setting that is being applied when I log in, or that /etc/rc.local only applies for the login screen itself and has no bearing on what happens to a user when logged in.

So, how do I resolve this so that the brightness and keyboard light settings I want apply to the user login session, not just to the login screen?

Community
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Questioner
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    Does manually executing this script work? – nitishch Feb 05 '14 at 10:12
  • @nitish, thanks for asking. I just tested now, and yes, it works. If I run it from the command line, it asks for my administrative password, and then when I enter that, it executes. – Questioner Feb 06 '14 at 02:50
  • what is the output of ls /sys/class/backlight/ – Raja G Feb 08 '14 at 05:43
  • The fact that xbacklight is not working when put in /etc/rc.local seems easy to explain... The X server has not started yet when the system executes this file. On the other hand, it is really strange that it is not working in your startup session option... – Rmano Feb 08 '14 at 05:57
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    How about when you put them in your .bashrc file in your home directory? – Parto Feb 08 '14 at 05:58
  • @AvatarParto: Thank you for the .bashrc suggestion. However, the keyboard command seems to require root permission, and unless I'm mistaken, .bashrc does not have root permission, only the logged in user. There must be a way to resolve that, though. After all, I can lower and turn off the keyboard backlight with a straight keyboard command, so it shouldn't be something that can only be done by root...? – Questioner Feb 08 '14 at 06:37
  • @DaveMG output of ls /sys/class/backlight/ please – Raja G Feb 08 '14 at 07:53
  • @rajagenupula: ls /sys/class/backlight/ acpi_video0 intel_backlight – Questioner Feb 08 '14 at 08:22
  • @AvatarParto: I've experimented with .bashrc, and it does not execute on login, it only executes when I open a terminal window. That is not as automatic as I would like it to be. – Questioner Feb 08 '14 at 09:12
  • How about adding a startup command in the form of a .desktop file under /etc/xdg/autostart. – Sadi Feb 08 '14 at 11:14
  • @Sadi,thank you for the suggestion. I have looked at other .desktop files to see how it works, but the format is not clear. Is there anywhere that might instruct me on how to use these particular commands within a .desktop file? – Questioner Feb 09 '14 at 04:56
  • You can put your executable script file to a location such as /usr/local/bin/lower-brightness and then enter this file in a new .desktop file under /etc/xdg/autostart/ like Exec=/usr/local/bin/lower-brightness together with other settings such as X-GNOME-Autostart-enabled=true and perhaps NoDisplay=false and/or Hidden=false. I hope this works, otherwise, I might have another suggestion ;-) – Sadi Feb 09 '14 at 09:28
  • @Sadi, thanks for that. I created a .desktop file, and unfortunately, the problem persists, but now I think it might be different than what I thought. I've opened another questions detailing the issue. – Questioner Feb 09 '14 at 11:53
  • Have you tried the xbacklight solution I've suggested as a separate answer? I tested and saw that it worked on my machine. – Sadi Feb 10 '14 at 09:45
  • Back to the .bashrc (or .profile) suggestion. If I got that right, the password was the only issue there. If so, you could define this command for your user not requiring a sudo password (via a corresponding line in /etc/sudoers.d/user-alias, e.g. dave ALL = NOPASSWD: /home/dave/startup.sh, and then execute sudo /home/dave/startup.sh from your .bashrc/.profile. – Izzy Feb 11 '14 at 23:33
  • @Izzy, thank you for the suggestion. I tried setting up the script file and .profile as you suggested, but it does not seem to be executing. Does .profile definitely execute at every startup? Also, I had to change sudo /home/dave/startup.sh to sudo sh /home/dave/startup.sh because otherwise when I tested it at the command line it said command not found. – Questioner Feb 12 '14 at 06:09
  • .profile is executed at login, .bashrc whenever you start a new bash shell (and there's also the .xprofile, executed on start of the X-Window session). And you might have needed to add the sh because you didn't make startup.sh executable (chmod +x startup.sh). – Izzy Feb 12 '14 at 09:20

5 Answers5

4

xbacklight solution

1) Create an executable script file e.g. /home/YOU/.bin/lower-brightness like this:

#!/bin/sh
xbacklight -set 7 &

2) Create a .desktop file e.g. /home/YOU/.config/autostart/lower-brightness.desktop like this:

[Desktop Entry]
Type=Application
Exec=/home/YOU/.bin/lower-brightness
Hidden=false
NoDisplay=false
X-GNOME-Autostart-enabled=true
Name=Lower Screen Brightness
Comment=Screen brightness is set to 7 at startup
Icon=display
Sadi
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1

To have the display settings as you want you can add this line in /etc/rc.local

echo 7 > /sys/class/backlight/intel_backlight/brightness

Then it can keep your brightness as 7.

hope that helps a bit.

Raja G
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  • Thank you for responding, but you seem to have missed the point of the question. It's not that I don't have the right commands, it's that the commands are not executing. – Questioner Feb 09 '14 at 04:54
  • Have you tried my solution? – Raja G Feb 09 '14 at 05:58
  • Yes, I tried your suggestion. Unfortunately, it had no different effect than any of the others offered. It may be due to a new dimension to the problem, which is one of competing commands. I have opened a new question to address this. – Questioner Feb 09 '14 at 08:40
1

I'm sure, my solution should help you if you use ubuntu with lightdm.

I was searching for turning on NumPad on my laptop when it starts and in lightdm documentation I found this:

# display-setup-script = Script to run when starting a greeter session (runs as root)
# greeter-setup-script = Script to run when starting a greeter (runs as root)
# session-setup-script = Script to run when starting a user session (runs as root)
# session-cleanup-script = Script to run when quitting a user session (runs as root)

And that is solution. You need to create file in /usr/bin/, say /usr/bin/backlight and write commands there.

#!/bin/bash
xbacklight -set 7
echo 0 | sudo tee /sys/class/leds/asus::kbd_backlight/brightness
exit 0

(Also xbacklight doesn't work for me. echo 7 > /sys/class/backlight/intel_backlight/brightness does the stuff). Than make sure you add execute permission for this file with chmod a+x /usr/bin/backlight.

Than you need to edit /etc/lightdm/lightdm.conf and write for example this line:

session-setup-script=/usr/bin/backlight

And that's it. Now restart you PC.

Viktor K
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1

Create your own init script to adjust the brightness levels. 

echo '#!/bin/sh 
sleep 60
echo 0 | tee /sys/class/leds/asus::kbd_backlight/brightness
xbacklight -set 7
exit 0' > /tmp/myinit
sudo mv /tmp/myinit /etc/init.d/myinit
sudo chmod +x /etc/init.d/myinit
sudo update-rc.d myinit defaults

Adjust the sleep value to your suit.

totti
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I wonder why no one has suggested using update-rc.d. I would not put the script into /etc/rc.local manually. I would recommend this way to make programs run at startup:

sudo cp lower-brightness.sh /etc/init.d/
sudo chmod +x /etc/init.d/lower-brightness.sh 
sudo update-rc.d lower-brightness.sh defaults

This will make sure the script is linked to appropriate run levels.

biocyberman
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  • Thank you for this suggestion. When I tried your solution, after logging in it seemed like my desired settings had applied. Unfortunately, though, as soon as I moved my pointer by using the laptop's touchpad, the screen brightness changed and the keyboard light came on again. I am extremely perplexed by this. – Questioner Feb 15 '14 at 06:05
  • That means your setting xbacklight -set 7 is not maintained after boot. Try changing to this xbacklight -set 7 & in your statup script to have the command run in background. – biocyberman Feb 17 '14 at 13:05
  • I added the & as you suggested, but that didn't change anything. I also tried removing the xbacklight command entirely so as to just get the keyboard to work, but when I did that, the keyboard light never shuts off at all. – Questioner Feb 18 '14 at 07:55