Ncurses

Dev Zone Code
1

Hey guys I am trying to take keyboard input in a c program. I want the down and up arrow keys to do something but every time I use them in the function getch() the char it returns is 27 which is the escape value.

while(1){
displayEnemyStatus(scale);
char userCommand = getch();
if(userCommand==KEY_UP){ /*Down List*/
scale++;
displayEnemyStatus(scale);
}
if(userCommand==KEY_DOWN){ /*Up Arrow*/
if(scale>-1){
scale--;
displayEnemyStatus(scale);
}
}
if(userCommand == 27){
clear();
printGrid();
wrefresh(window);
break;
}

            }
            break;
2

  1. If you're going to have the brackets at the end of the line, at least fix the tabbing so it's readable.

  2. Print userCommand as an int and see what comes out.

3

That just messed up from copying for some reason, but I will check what happens if I get the int. It still appears to print 27.

4

Do you have a special keyboard with lots of extra features?

Are you running some keyboard software?

5

no I am using Linux and my keyboard is a IBM model M keyboard.

6

oh, ok. Is it just ps2?

If so, I dunno what your issue is...

7

I see you like to live dangerously.

1 Like
8

maybe try something like

char c = '';
scanf(" %c", c); //note the space before the %
9

well I found that when I would do getch() and hit an arrow key it would send three messages to ncurses, 27,[,A for up arrow for example. The problem now is when I do getch() again and I want to hit the escape key it waits for a command but when I hit an arrow key it doesn't wait because that pushes multiple things while escape just pushes 27.

 while(!escape){
                clear();
                refresh();
                displayEnemyStatus(scale);
                char userCommand = getch();
                if(userCommand==27){
                getch();
                userCommand = getch();
                escape=1;
                if(userCommand=='B'){ /*Down List*/
                    scale++;
                    escape=0;
                }
                if(userCommand=='A'){ /*Up Arrow*/
                    if(scale>-1){
                        scale--;
                        escape=0;
                    }
                }
                }
                }
                    clear();
                    printGrid();
                    wrefresh(window);
10

Ah, yess.... forgot about escape sequence comes first for special characters.

I would check the freeglut code base. I know they are able to handle it just fine. See what they did.

11

Do you think there is a way to change it in system settings on Linux Mint to output a combined value like 66 or 65 or better yet if I could access everything in the ncurses input buffer without calling getch()?