creadlinencurseskeypadlibreadline

Readline & NCurses, handle special keys and keys combinations

I'm replicating an Irssi interface for a student project. I would like to use NCurses for the text interface, and readline to provide better text-editing capabilities while writing messages.

This question, answer and project provided me with a great starting point.

My problem is that I would like to have an input/event loop like this:

int ch;
while (exit_condition) {
    ch = wgetch(window);
    switch (ch) {
    case ERR: continue;
    case KEY_F(1): /* do something */ break;
    case KEY_UP: /* do something else */ break;
    default: forward_to_readline(ch); break;
    }
}

But in order to match KEY_F(n) or KEY_UP I need to enable keypad(window, TRUE), which will modify the input and make it unusable for readline.

From the manual:

If keypad is TRUE, and a function key is pressed, the token for that function key is returned instead of the raw characters.

When a character that could be the beginning of a function key is received (which, on modern terminals, means an escape character), curses sets a timer. If the remainder of the sequence does not come in within the designated time, the character is passed through; otherwise, the function key value is returned. For this reason, many terminals experience a delay between the time a user presses the escape key and the escape is returned to the program.

Here are my thoughts:

Thank you for your time !

Solution

  • That's multiple questions. Briefly: