mpitest.c

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

int main (int argc, char **argv) {
        int rc;
        int size;
        int myrank;

        rc = MPI_Init (&argc, &argv);
        if (rc != MPI_SUCCESS) {
                fprintf (stderr, "MPI_Init() failed");
                return EXIT_FAILURE;
        }

        rc = MPI_Comm_size (MPI_COMM_WORLD, &size);
        if (rc != MPI_SUCCESS) {
                fprintf (stderr, "MPI_Comm_size() failed");
                goto exit_with_error;
        }

        rc = MPI_Comm_rank (MPI_COMM_WORLD, &myrank);
        if (rc != MPI_SUCCESS) {
                fprintf (stderr, "MPI_Comm_rank() failed");
                goto exit_with_error;
        }

        fprintf (stdout, "Hello, I am rank %d/%d", myrank, size);


        MPI_Finalize();

        return EXIT_SUCCESS;

         exit_with_error:
        MPI_Finalize();
        return EXIT_FAILURE;
}