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pythoncurses

How to intercept special (alt / ctrl) key press?


How can I catch key combinations like ALT+K or CTRL+ALT+H in python curses?


Solution

  • A terminal converts the control key in combination with a letter key to a normal ASCII code. This can be read from the getch() function like any other key press.

    CTRL-A: getch() returns 1
    CTRL-B: getch() returns 2
    ...
    CTRL-Z: getch() returns 26
    

    Also, the keypad() function must be called to enable other special function keys (e.g. left arrow, F1, home, etc).

    I don't believe there is a portable way to receive meta-keys (e.g. ALT-H) through a terminal. Some send an escape (0x1B) followed by the modified key while others set the high-bit and only send one byte.