Completely disable Alt in Raspbian

Question

I am looking to develop a raspberry pi into something that I can run a free public web terminal that will be blocked for a specific domain. This is for my employer, a village who wants to create terminals around the village, so that the less successful in our community can communicate and interact with the various services that the village provides, without being able to find a way to the administration center.

I managed to get most of what I need, but I want to disable the Alt key on the keyboard. This will stop users from being able to Ctrl + Alt + Del or Alt + F4 to exit the browser environment and other other LXDE functions that smart users can use to break my kiosk (for example, virtual terminals). I thought I found a way to do this with xmodmap, but when I ran this command

xmodmap -e "keycode 204 = " 

As far as I know, all the bindings for the right Alt key should be bound to zero, but still Alt + F4 allows me to chrome and other things.

I also tried editing my ~/.config/openbox/lxde-rc.xml and changing the keyboard bindings in it. I managed to disable Ctrl + Alt + Del , but when I change or erase other key bindings there, nothing happens. Therefore, I am trying to find out other parameters that I have to disable by pressing the Alt key in this application. Any ideas?

Answer 1

Su, I just answered my question. The fix for the problem really lies in the ~/.config/openbox/lxde-rc.xml , but I did not do it right. To set the Ctrl Alt Delete option, you need to change the value between <command></command> and false (or the program that gives the user a finger).

The problem was that only four key input elements have a <command> field, and all others use the <action="whatever"></action> field to determine the action that the key takes. I changed the value of “everything” to “false” and was under the impression that would have the same effect as changing the team field.

But in fact, you need to change the value of "whatever" to "Execute", and then insert the set <command></command> with the value set to false and set the key mapping to false. I assume that there should be a set of default values ​​that are used to override incorrect changes to the lxde-rc.xml files, and why everything works after deleting entries.