How to change LCD brightness from command line (or via script)?

http://askubuntu.com/questions/149054/how-to-change-lcd-brightness-from-command-line-or-via-script

one more way we have to do this is with another new program named as xbacklight , open your terminal and type this

sudo apt-get install xbacklight

then type this xbacklight -set 50

there 50 stands for brightness range we can get it upto 100 from 0 .

you can also increase and decrease the brightness from present value to specified level.as you mentioned if you want to increase to 10% from current value of brightness then you can give this

xbacklight -inc 10

and to decrease 10% you can give this

xbacklight -dec 10