change scroll speed linux

# http://www.webupd8.org/2015/12/how-to-change-mouse-scroll-wheel-speed.html

sudo apt-get install imwheel

nano ~/.imwheelrc

# in .imwheelrc file, paste
".*"
None,      Up,   Button4, 3
None,      Down, Button5, 3
Control_L, Up,   Control_L|Button4
Control_L, Down, Control_L|Button5
Shift_L,   Up,   Shift_L|Button4
Shift_L,   Down, Shift_L|Button5

# type in terminal to re-launch imwheel
imwheel --kill

# if you have back / forward navigation buttons on your mouse
imwheel --kill -buttons "4 5"