= Source code =
{{{
/* Program:
 *   讓 node 0 可以接受來自任何 node 的訊息
 * History:
 *   2008-06-24 BETA
 */

#include <stdio.h>
#include <mpi.h>

main (int argc, char **argv)
{
  int numprocs, myrank, i=0, buf;
  MPI_Status status;
  MPI_Init(&argc, &argv);
  MPI_Comm_size(MPI_COMM_WORLD, &numprocs);
  MPI_Comm_rank(MPI_COMM_WORLD, &myrank);

  if (myrank > 0)
  {
    for(i = 0; i < 5; i++)
    {
      buf = myrank * 100 + i;
      MPI_Send(&buf, 1, MPI_INT, 0, i, MPI_COMM_WORLD);
    }
  }
  if (myrank == 0)
  {
    for (i = 0; i < 5*(numprocs-1); i++)
    {
      MPI_Recv(&buf, 1, MPI_INT, MPI_ANY_SOURCE, MPI_ANY_TAG, MPI_COMM_WORLD, &status);
      printf("[Node %d][Tag %d] => %d\n", status.MPI_SOURCE, status.MPI_TAG, buf);
    }
  }
  MPI_Finalize();
}

}}}

= Result =
[[Image(demo4-01.png)]]