Use Function Keys without pressing the fn button in the mac keyboard?

The article there should help you.

I inserted these two echo lines into /etc/rc.local:

echo 2 > /sys/module/hid_apple/parameters/fnmode
echo 2 > /sys/module/apple/parameters/fnmode

Those are inserted just before the "exit 0" line.

From the Ubuntu community wiki on Apple Keyboards... Open this file with root permissions in terminal:

gksudo gedit /etc/modprobe.d/hid_apple.conf

Then add to the end of the file:

options hid_apple fnmode=2

And then finally in terminal...

sudo update-initramfs -u

Reboot your computer.

This will change the default keys to being the Function keys, E.g F8 is F8 instead of Play/Pause song. Hope this helps! ^.^