How do I detect arrow keys pressed using curses in C?

Question

In trying to get input from the arrow keys via curses (ncurses) it won't catch as KEY_UP etc. I used the keypad function with a true argument but getch still returned an escaped sequence. How do I shift through the values returned by getch() and grab the arrow keys specifically?

Solution 1

I found the same problem on Mac OS X. But it was resolved by adding the following:

keypad(stdscr, TRUE);

Solution 2

Standard (VT100-like) terminals send a sequence of characters when the arrow keys are pressed. You just have to keep track of whether or not these are pressed in sequence. Here are the char's to watch for:

Down Arrow  0x1B 0x5B 0x42
Left Arrow  0x1B 0x5B 0x44
Right Arrow 0x1B 0x5B 0x43
Up Arrow    0x1B 0x5B 0x41

Comments

[Sean A.O. Harney]

Are there escape codes you could enter as a key combination or sequence using ctrl for these?

[Ryan Ballantyne]

No need; you can type them directly. 0x1B = esc, 0x5B = [, and 0x41 - 0x44 = A - D. Type esc[D in your terminal, and the cursor moves to the left.

[Andrew Y]

This approach pretty much fully defeats the whole purpose of working with curses library in the first place :-)

[bpisano]

This and storing getch as int worked for me.