The function

 pthread_join(thread, ptr)
   

provides a way to wait for a thread to terminate and get its exit/return value.

• First argument is the thread id of the thread to wait for.

• The second (if not 0) indicates where the return value should go.

• The return value is 0 if successful or else an error number.

void rlogind(int r_in, int r_out, int l_in, int l_out) 
{
  pthread_t in_thread, out_thread;
  fd_pair_t in = {r_in, l_in};
  fd_pair_t out = {r_out, l_out};

  pthread_create(&in_thread, 0, incoming, (void *) &in);
  pthread_create(&out_thread, 0, outgoing, (void *) &out);

  pthread_join(in_thread, 0);
  pthread_join(out_thread, 0);
}