If you have an Apple keyboard and want the function keys to act like F1-F12 by default (disable Fn default behavior) give the following command in terminal:
echo 2 | sudo tee /sys/module/hid_apple/parameters/fnmode
As far as I know, the Fn key does not get detected by the OS but modifies your other keys on a firmware level. That means you can neither retrieve nor control the state of the Fn key from Ubuntu.
What you could do instead is to change the keyboard shortcut for increasing/decreasing audio volume to an alternative key combination instead of the Fn-modified special key.
Open System Settings → Keyboard and go to the Shortcuts tab. In the list on the left side, select Sound and Media.
After clicking on an entry in the list on the right side (in your case you want to edit Volume up and Volume down), you can press a combination of keys you want to assign to this shortcut. Esc cancels the editing and ← Backspace disables the shortcut.
My laptop has a Fn Lock key which is useful, except when it's been pressed by accident. Then pressing F5 in Firefox doesn't reload the page; it switches off the touch pad. I now know what it is but it had me totally bamboozled having to reboot or logout to get the touch pad back working.
For some computer models, to toggle F1 .. F12 keys use media functions or to be the "F" keys press Fn + Esc .
If you have an Apple keyboard and want the function keys to act like F1-F12 by default (disable Fn default behavior) give the following command in terminal:
from here: https://help.ubuntu.com/community/AppleKeyboard#Change_Function_Key_behavior
As far as I know, the Fn key does not get detected by the OS but modifies your other keys on a firmware level. That means you can neither retrieve nor control the state of the Fn key from Ubuntu.
What you could do instead is to change the keyboard shortcut for increasing/decreasing audio volume to an alternative key combination instead of the Fn-modified special key.
Open System Settings → Keyboard and go to the Shortcuts tab. In the list on the left side, select Sound and Media.
After clicking on an entry in the list on the right side (in your case you want to edit Volume up and Volume down), you can press a combination of keys you want to assign to this shortcut. Esc cancels the editing and ← Backspace disables the shortcut.
Press Fn+Fn Lock. It will toggle between Enable and Disable.
My laptop has a Fn Lock key which is useful, except when it's been pressed by accident. Then pressing F5 in Firefox doesn't reload the page; it switches off the touch pad. I now know what it is but it had me totally bamboozled having to reboot or logout to get the touch pad back working.
On HP probook 450, left shift has fn lock, so fn+leftShift locks it.
Press Fn+Num Lock to disable it.
Look in the BIOS. For Acer laptop I can choose the toggle on Fn touch in it.
In addition to zardosht answer above as I cannot comment yet.
To make this work after reboots I followed Zanna's link to add in
sysfutilsUbuntu 17.04 Macbook Pro Tilde key FixAdded this in the last line to end of file
module/hid_apple/parameters/fnmode = 2save, reboot and should be working.
Thanks!
On some Keyboard, the left shift is the fn lock key. Press fn+left shift to toggle