Alternative to sprintf for pebble SDK (no need for stdio.h)

itoa.c

char *itoa(int num)
{
  static char buff[20] = {};
  int i = 0, temp_num = num, length = 0;
  char *string = buff;

  if (num >= 0) {
    while(temp_num) {
      temp_num /= 10;
      length++;
    }

    for (i = 0; i < length; i++) {
      buff[(length-1)-i] = '0' + (num % 10);
      num /= 10;
    }
    buff[i] = '\0'; // can't forget the null byte to properly end our string
  }
  else {
    return "Unsupported Number";
  }
  return string;
}