c - getch and arrow codes

Question

I'm writing a programm that's using getch() to scan for arrow keys. My code so far is:

switch(getch()) {
    case 65:    // key up
        break;
    case 66:    // key down
        break;
    case 67:    // key right
        break;
    case 68:    // key left
        break;
}

Problem is that when I press 'A', 'B', 'C' or 'D' the code will also executed, because 65 is the decimal code for 'A', etc...

Is there a way to check for an arrow key without call others?

Thanks!

Answer 1

By pressing one arrow key getch will push three values into the buffer:

• '33'
• '['
• 'A', 'B', 'C' or 'D'

So the code will be something like this:

if (getch() == '33') { // if the first value is esc
    getch(); // skip the [
    switch(getch()) { // the real value
        case 'A':
            // code for arrow up
            break;
        case 'B':
            // code for arrow down
            break;
        case 'C':
            // code for arrow right
            break;
        case 'D':
            // code for arrow left
            break;
    }
}