Detect meta (special) keys (Ctrl, Shift, Alt, Tab, Esc, Backspace) from Shell Input

Question

I want to know if anybody knows how to detect meta (special) keys (Ctrl, Shift, Alt, Tab, Esc, Backspace)

Answer 1

In general, you cannot do it. That said:

• X11 sends KeyPress and KeyRelease events.
• The Linux console provides a set of ioctls that allow low-level access to the keyboard, documented at console_ioctl(4). You would set the keyboard to RAW or MEDIUMRAW mode (don't confuse these modes with termios' raw mode, they are not related at all).

Answer 2

I'm not sure it always make sense. The tty discipline is doing something (details are gory). Perhaps you need a helper program (e.g. in C, which would use a library like ncurses or readline) such as dialog!