title: How to wait for exit of non-children processes
body: <p>For child processes, the <code>wait()</code> and <code>waitpid()</code> functions can be used to suspends  execution  of  the current process until a child has exited. But this function can not be used for non-child processes. </p>
  
  <p>Is there another function, which can wait for exit of any process ?</p>