Hi everyone.
Here's the scoop. Getting Firefox to utilize mouse side buttons isn't all too hard. Getting them to work in Epiphany and Nautilus requires a bit more work. Why? I have no idea. I'm pretty sure gnome could support mouse side buttons, without having to resort to lots of ridiculous text editing and the installation of third party hacks like imwheel. But I digress.
Anyhow, to begin, if you want to edit everything with a nice text editor and not something overly terminal-ish, you can simply just type:
su
[root password]
gedit
ONE
First, open your xorg.conf file. It should be:
/etc/X11/xorg.conf
Now, scroll down to the section that looks like this:
Section "InputDevice"
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "ExplorerPS/2"
Option "Device" "/dev/input/mice"
Option "Buttons" "7"
Option "ZAxisMapping" "6 7"
EndSection
This is how your config file should look if you have a typical 5 button mouse (I use a logitech mx1000 laser and this works fine). The reason it says "Buttons" "7" is because your scroll up and scroll down also count as buttons. Make sure "Protocol" is set to "ExplorerPS/2" and "ZAxisMapping" is set to "6 7"
Now save! We're all done with that file. Gedit automatically creates a backup in case you screw up, xorg.conf~
TWO
Now you need to create a new file. Copy and paste exactly what you see here into it:
#!/bin/sh
# /etc/X11/xinit/xinitrc.d/mouse.sh
# Required for the configuration of a 5-button mouse
xmodmap -e "pointer = 1 2 3 6 7 4 5"
If you're going to go the extra mile and get Epiphany / Nautilus to work, then you also need to add one additional line here:
imwheel -k -b "67"
Either way, you then need to save the file as mouse.sh in the folder: /etc/X11/xinit/xinitrc.d
Okey... now, if you did not include the extra line and only want the side buttons to work in firefox, you're done. Simply restart. Your side buttons should work fine and dandy now.
THREE
If you went the extra step above and included the extra line, then you need to install imwheel. Imwheel is a third party program that can take button presses from your mouse and send it to gnome/kde/whatever as if you were pressing certain key combinations on your keyboard. This can make Epiphany and Nautilus go back and foward (try pressing Alt + L + left or Alt + L + right and see for yourself).
Click here to download it (thanks to fnxweb). Just double click it in nautilus to install (or type the whole rpm command out in a terminal if that's your thing).
Once it's installed, you have one more text file to create (we're almost done ). This time you do not need root access. Just fire up text editor from Applications > Accessories. Copy and paste what you see here:
".*"
None, Up, Alt_R|Left
None, Down, Alt_R|Right
Save this as ".imwheelrc" in your home directory.
Now you should be all done. Just restart. Side buttons should preform as back and forward buttons in Firefox, Epiphany, and Nautilus now.