Terminal Turn Hardware Keys On And Off

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Level 1

25 points

Terminal Turn Hardware Keys On And Off

I'm trying to script turning on and off the hardware keys on my MacBook that control the volume and brightness. I have a game which I like to assign the function keys to certain controls and going into System Preferences every time I want to play is a hassle.

If someone could tell me how to do this using the +defaults write+ command that would be most appreciated.

The preference is located in: +System Preferences > Keyboard & Mouse > Keyboard > Use all F1, F2, etc. keys as standard function keys+ and it is just a simple check box.

13in. MacBook 2GHz Core 2 Duo 2GB RAM, Mac OS X (10.5.2)

Posted on Feb 23, 2008 2:39 PM

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Answer 1

Top-ranking reply

Michael Conniff

Level 7

33,149 points

Feb 24, 2008 10:33 AM in response to Matt Skorina

Matt

You can do this with

defaults write -g com.apple.keyboard.fnState true

Undoing it should be obvious 😉

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Answer 2

Matt Skorina Author

Level 1

25 points

Feb 24, 2008 5:40 PM in response to Michael Conniff

Thanks Michael, that got me in the right direction but it didn't work.

Before I wrote to com.apple.keyboard.fnState I read from it to see what was there.

defaults read -g com.apple.keyboard.fnState

When the checkbox was on in System Preferences (acted like function keys) the above resulted in 1. When the checkbox was off (hardware keys) it resulted in 0.

When I ran +defaults write -g com.apple.keyboard.fnState true+ it didn't make the keys only work as function keys, in fact it didn't change anything. If I wrote a true or a false the keys didn't change from whatever they were set to before I ran that command.

When I read back com.apple.keyboard.fnState whatever I had written to before was there. Writing false to that preference resulted in false being returned and the key type never changing.

If I wrote a 1 or a 0 it didn't change how the keys behaved yet checking or unchecking the System Preferences checkbox (resulting in a 1 or 0 being read from the preference) would change the behavior of the keys.

I even restarted (effectively killing all processes). That resulted in the sum total of nothing. I'm really stumped on this one. Googling "fnstate" resulted in a handful of of cases just like this that I hadn't discovered in my previous Googlings. None of them with a solution that worked for me.

Is there some silly mistake that I'm making here or what?

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Answer 3

Feb 25, 2008 12:56 PM in response to Matt Skorina

Matt

I did not have this property in my plist initially, so I backed up the file and changed it in the GUI. I then discovered this entry in "~/Library/Preferences/.GlobalPreferences.plist":

<key>com.apple.keyboard.fnState</key>
 <false/>

But defaults read -g com.apple.keyboard.fnState will return this as '0', or '1' if the value is <true/>.

However, the command I posted omitted an important flag, to prevent whatever is input being treated as a string 😟 So try:

defaults write -g com.apple.keyboard.fnState -boolean true

Now the read command will display '1', but in the file the value will be '<true/>'.

Sorry I missed that out before!

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