getch() or noecho() -> segmentation fault !

frenchi · 07-23-2004, 02:47 AM

Hi there !
I've got a problem, I just tried to detect a key has been pressed, but it doesn't seem to work, little explanation :

Code:

#include <curses.h> /* And other ;)*/
int main(void)
{
int return_echo;

return_echo=noecho();/* Even if there is this only instruction*/
printf("%d", return_echo);/*optionnal*/

return 0;
}

When I compile it with Wall and everything (gcc), I haven't got any error.
If I try it, I've got a "segmentation fault", noecho() or getch() does the same thing...
I'm disappointed, what can I do

Thanks in advance !

Hko · 07-23-2004, 05:42 AM

noecho() is a function from the ncurses library. And you cannot use ncurses-functions until you initialize the ncurses screen with initscr(). When you're program is done with the ncurses-screen you need dispose if off with endwin(). While ncurses screen is active (i.e. code between initscr() and endwin() ) printf()'s will not work. So you need to do the printf() after closing the ncurses screen with endwin().

Fixed program:

Code:

#include <curses.h>

int main(void)
{
	int return_echo;

	initscr();
	return_echo=noecho();
	endwin();

	printf("%d\n", return_echo);  /* note: After endwin() */
	return 0;
}

( compile with "gcc -Wall -lncurses -o progname progname.c" )

psiakr3w · 07-23-2004, 10:50 PM

I actually ran into the same problem when I tried out something that was suggested in another thread. But then I searched google for 'ncurses' and came up with the following:

http://en.tldp.org/HOWTO/NCURSES-Programming-HOWTO/

which got me to try its Hello World program (chapter 2) and all was well again

Check it out.