Function keys and strange results

divineleft · 11-10-2006, 07:58 PM

Hello.

I'm writing a small game for fun and I'm having a problem with the function keys, specifically F1-F4.

Code:

#include <curses.h>

void input()
{
    int choice;
    choice = getch();
    printw("%c\n", choice);
    refresh();
}

When I press any other function key, the character returns as "^Q" or "^R", but for some reason those 4 keys (F1-F4) return things like "^[[11~". Even when I do something like:

Code:

if(choice == KEY_F(1))     // or F2,F3,F3
{
    ...
}

it doesn't work. But, If I use any of the other function keys, it works. Is this a hardware problem on my side, or am I just doing something wrong? It's not just for ncurses either, it happens regardless.

I'm on linux, if that's of any help.

**Salem** · 11-11-2006, 02:24 AM

Can you post a short and complete ncurses program which prints your function keys?

Your F1 to F4 keys are generating ANSI Escape sequences, which is something they can be programmed to do in various kinds of terminal emulation modes. How you change that depends on what you're using.

divineleft · 11-11-2006, 06:33 AM

Sure.

Code:

#include <curses.h>
#include <iostream>


void menu();

int main()
{
	initscr();
	keypad(stdscr, TRUE);
	noecho();
	scrollok(stdscr, TRUE);
	
	menu();
	
	endwin();
	return 0;
}

void menu()
{
    int choice;
    while (choice = getch())
    {
    	printw("%c\n", choice);
    	refresh();
    }
}

jim mcnamara · 11-12-2006, 06:39 AM

ncurses returns an integer - some keys like F1 send 265, if I remember, by default in ncurses. Which is beyond the limits for unsigned char. getch() returns an integer.

11-10-2006, 07:58 PM	#1
divineleft Registered User Join Date: Jul 2006 Posts: 158	Function keys and strange results Hello. I'm writing a small game for fun and I'm having a problem with the function keys, specifically F1-F4. Code: #include <curses.h> void input() { int choice; choice = getch(); printw("%c\n", choice); refresh(); } When I press any other function key, the character returns as "^Q" or "^R", but for some reason those 4 keys (F1-F4) return things like "^[[11~". Even when I do something like: Code: if(choice == KEY_F(1)) // or F2,F3,F3 { ... } it doesn't work. But, If I use any of the other function keys, it works. Is this a hardware problem on my side, or am I just doing something wrong? It's not just for ncurses either, it happens regardless. I'm on linux, if that's of any help. Last edited by divineleft; 11-10-2006 at 08:26 PM.
divineleft is offline

11-11-2006, 02:24 AM	#2
Salem and the hat of Jobseeking Join Date: Aug 2001 Location: The edge of the known universe Posts: 21,680	Can you post a short and complete ncurses program which prints your function keys? Your F1 to F4 keys are generating ANSI Escape sequences, which is something they can be programmed to do in various kinds of terminal emulation modes. How you change that depends on what you're using. __________________ If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
Salem is offline

11-12-2006, 06:39 AM	#4
jim mcnamara . Join Date: Nov 2003 Posts: 293	ncurses returns an integer - some keys like F1 send 265, if I remember, by default in ncurses. Which is beyond the limits for unsigned char. getch() returns an integer.
jim mcnamara is offline

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