Simplest MPI test program

simplempi.c

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

main(int argc, char **argv)
{
    int node;

    MPI_Init(&argc, &argv);
    MPI_Comm_rank(MPI_COMM_WORLD, &node);

    printf("MPI test from node %d\n", node);

    MPI_Finalize();
}