// compile with   mpicc -o mpiHelloWorld mpiHelloWorld.c 

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

int main(int argc, char** argv)
{
    int rank, size, nameLen;
    char processorName[MPI_MAX_PROCESSOR_NAME];

    MPI_Init(&argc, &argv);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
    MPI_Comm_size(MPI_COMM_WORLD, &size);

    MPI_Get_processor_name(processorName, &nameLen);

    printf("Hello, rank %d, size %d on processor %s\n", 
          rank, size, processorName);

    MPI_Finalize();
    return 0;
}