Non-blocking getch(), ncurses

Question

I'm having some problems getting ncurses' getch() to block. Default operation seems to be non-blocking (or have I missed some initialization)? I would like it to work like getch() in Windows. I have tried various versions of

timeout(3000000);
nocbreak();
cbreak();
noraw();
etc...

(not all at the same time). I would prefer to not (explicitly) use any WINDOW, if possible. A while loop around getch(), checking for a specific return value is OK too.

Answer 1

You need to call initscr() or newterm() to initialize curses before it will work. This works fine for me:

#include <ncurses.h>

int main() {
    WINDOW *w;
    char c;

    w = initscr();
    timeout(3000);
    c = getch();
    endwin();

    printf("received %c (%d)\n", c, (int) c);
}

Answer 2

The curses library is a package deal. You can't just pull out one routine and hope for the best without properly initializing the library. Here's a code that correctly blocks on getch():

#include <curses.h>

int main(void) {
  initscr();
  timeout(-1);
  int c = getch();
  endwin();
  printf ("%d %c\n", c, c);
  return 0;
}

Answer 3

From a man page (emphasis added):

The timeout and wtimeout routines set blocking or non-blocking read for a given window. If delay is negative, blocking read is used (i.e., waits indefinitely for input).