Brightness controls

Although the brightness controls work, they operate in rather large steps. If you use your laptop at night, like I do, then you might want to get the screen darker without turning off completely.

You can do this by writing a value directly to:

/sys/class/backlight/intel_backlight/brightness

as the root user.

I adapted a previous script I wrote to do this and bound this to a shortcut key which now gives an additional 3 steps between the current darkest setting and 'off'. I will upload the script and associated polkit later.

$ cat set-brightness
#!/bin/sh
echo "$1" > /sys/class/backlight/intel_backlight/brightness

$ cat brightness

#!/bin/sh

# Control screen brightness on Acer V3-372

#

# Adjusts brightness between 0 and 187

# Usage: brightness [u|d]

PKEXEC=/usr/bin/pkexec

#GSDBL=/usr/lib/gnome-settings-daemon/gsd-backlight-helper

#GSDBL=/usr/lib/xserver-xorg-video-intel/xf86-video-intel-backlight-helper

GSDBL=/usr/local/bin/set-brightness

#BRIGHTNESS=$( ${PKEXEC} ${GSDBL} --get-brightness )

BRIGHTNESS=$(cat /sys/class/backlight/intel_backlight/brightness )

case "$1" in

   u* ) 

${PKEXEC} ${GSDBL} $(($BRIGHTNESS*2))  

if [ "$BRIGHTNESS" -ge "90" ]

then ${PKEXEC} ${GSDBL} "187"  

elif [ "$BRIGHTNESS" -eq "0" ] 

then ${PKEXEC} ${GSDBL} "1"  

#else 

# ${PKEXEC} ${GSDBL} $(($BRIGHTNESS*2))  

fi

;;

   d* ) 

if [ "$BRIGHTNESS" -gt "186" ]

then ${PKEXEC} ${GSDBL} "128"  

elif [ "$BRIGHTNESS" -eq "1" ] 

then ${PKEXEC} ${GSDBL} "0"  

else 

${PKEXEC} ${GSDBL} $(($BRIGHTNESS/2))  

fi

;;

esac

BRIGHTNESS=$(cat /sys/class/backlight/intel_backlight/brightness )

echo "Screen brightness = " $BRIGHTNESS "/187"

/usr/bin/notify-send -t 500 $BRIGHTNESS"/187"

exit 0

$ cat org.freedesktop.policykit.exec.policy 

<?xml version="1.0" encoding="UTF-8"?>

   <!DOCTYPE policyconfig PUBLIC

"-//freedesktop//DTD PolicyKit Policy Configuration 1.0//EN"

"http://www.freedesktop.org/standards/PolicyKit/1/policyconfig.dtd">

   <policyconfig>

<vendor>Examples for the PolicyKit Project</vendor>

<vendor_url>http://hal.freedesktop.org/docs/PolicyKit/</vendor_url>

<action id="org.freedesktop.policykit.exec.run.set-brightness">

  <description>Run the PolicyKit example program Frobnicate</description>

  <description xml:lang="da">Kør PolicyKit eksemplet Frobnicate</description>

  <message>Authentication is required to run the PolicyKit example program Frobnicate (user=$(user), program=$(program), command_line=$(command_line))</message>

  <message xml:lang="da">Autorisering er påkrævet for at afvikle PolicyKit eksemplet Frobnicate (user=$(user), program=$(program), command_line=$(command_line))</message>

  <icon_name>audio-x-generic</icon_name>

  <defaults>

<allow_any>no</allow_any>

<allow_inactive>no</allow_inactive>

<allow_active>yes</allow_active>

  </defaults>

  <annotate key="org.freedesktop.policykit.exec.path">/usr/local/bin/set-brightness</annotate>

</action>

</policyconfig>