I cannot get the first simple example working.

  int main()
  {
      while (1) {
          if (fork())
              _exit(0);
      }   
      return 0;
  }

If I run `htop` immediately after typing `./a.out`, it shows a error,

  Could not create child process - exiting
  fork: Resource temporarily unavailable

However, if I wait a second or more, I cannot find `a.out` in the process list.