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

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

        int size,rank;
        int length;
        char name[80];
        MPI_Status status;
        int i;

        MPI_Init(&argc, &argv);
        // note that argc and argv are passed by address

        MPI_Comm_rank(MPI_COMM_WORLD,&rank);
        MPI_Comm_size(MPI_COMM_WORLD,&size);
        MPI_Get_processor_name(name,&length);

        if (rank==0) {
        // server commands
                printf("Hello MPI from the server process!\n");
                for (i=1;i<size;i++) {
                        MPI_Recv(name,80,MPI_CHAR,i,999,MPI_COMM_WORLD,&status);
                        printf("Hello MPI!\n");
                        printf(" mesg from %d of %d on %s\n",i,size,name);
                }
        } else {
                // client commands
                MPI_Send(name,80,MPI_CHAR,0,999,MPI_COMM_WORLD);
        }

        MPI_Finalize();
        return 0;
}