char* convert(char* dst, const char* src) {
  char* end = src + strlen(src) - 1;
  char* start = src;
  while (isspace(*start)) {
    start++;
  }

  while (isspace(*end) && end > start) {
    end--;
  }

  memcpy(dst, start, end - start + 1);
  return dst;
}