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When you are running Raspbian without graphics (GNU bash), only in bash mode, if you press ALT+F2, ALT+F3... you switch from current tty to another.
How to make that if you press these shortcuts nothing happens? Not even switching, nothing.

Why do I need that? I have a Raspberry without screen launching a python script on launch that listen keyboard entry, I already catch all ctrl+c, ctrl+\, ctrl+Z etc. but the user can switch tty and then it's no more on the tty1 with the script running.

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    There might be a better solution. However if not, you could redefine keys. Run dumpkeys | grep -i console to see what keys manage VT switching. Read also the loadkeys and keymaps manpage.
    – VPfB
    Commented Jun 10, 2017 at 16:23
  • Hi, thanks to this link and also showkey I identified the correct keycode to disable... yet I don't understand how to disable them... I tested keymaps alt keycode 105= and many others in bash but none are working... Do you have a tips for me?
    – Jeff86
    Commented Jun 10, 2017 at 17:09

1 Answer 1

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As VPfB says you can find all the key mappings that switch to the console eg with

dumpkeys | grep Console >/tmp/map

This gives a long list of keys eg:

altgr   keycode  59 = Console_13      
alt     keycode  59 = Console_1       
control alt     keycode  59 = Console_1       
altgr   keycode  60 = Console_14      

Replace the Console_* part of these with VoidSymbol:

altgr   keycode  59 = VoidSymbol
alt     keycode  59 = VoidSymbol
control alt     keycode  59 = VoidSymbol
altgr   keycode  60 = VoidSymbol

and pass the new file back into loadkeys to change the mapping

sudo loadkeys /tmp/map

You could also try just reducing the number of VTs to 1, probably in /etc/inittab for rasbian, or use the keyboard in raw mode, which is not easy as you will then have to map the key scancodes yourself.

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