NCurses and ESC,ALT keys

Question

I have a problem with NCurses... i need to handle all keys like Esc, Alt+F etc. Problem is that the codes are similar... i.e:

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Esc - 27

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Alt+A - 27 65

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As an example there is double code for Alt+[key] combination what similar to Esc key... Any ideas how handle that?

Answer 1

Here is an example for python:

key = self.screen.getch()
if key == ord('q'): # quit
    go = False
elif key == 27: # Esc or Alt
    # Don't wait for another key
    # If it was Alt then curses has already sent the other key
    # otherwise -1 is sent (Escape)
    self.screen.nodelay(True)
    n = self.screen.getch()
    if n == -1:
        # Escape was pressed
        go = False
    # Return to delay
    self.screen.nodelay(False)

Answer 2

Resolved by:

1. Use noecho or timeout mode
2. Check for 27(ALT or ESC) code... if pass:
3. try to read another code
4. if another code is ERR then.. you have ESC key in other way you have ALT+another code

Answer 3

You can use curses.ascii.ESC

• https://docs.python.org/3/library/curses.ascii.html#module-curses.ascii
• https://github.com/python/cpython/blob/master/Lib/curses/ascii.py