/*

 * mpicode.c

 * Simple send and Receive

 *      Author: Kostas Diamantaras

 */

#include <stdio.h>

#include "mpi.h"

#include <math.h>

#include <string.h>

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

int rank, size, i;

int count;

int tag = 50;

char message[100];

MPI_Status status;

MPI_Init( &argc, &argv );

MPI_Comm_size( MPI_COMM_WORLD, &size );

MPI_Comm_rank( MPI_COMM_WORLD, &rank );

if (rank != 0) {     /* Send message to process 0 */

printf("Process %d: sending message to process 0\n", rank);

fflush(stdout);

sprintf(message, "Hello from process %d of %d", rank, size);

MPI_Send(message, strlen(message), MPI_CHAR, 0, tag, MPI_COMM_WORLD);

       }

if (rank == 0) {     /* Receive messages from other processes and print them out */

for (i = 1; i < size; i++ ) {

MPI_Recv(message, 100, MPI_CHAR, i, tag, MPI_COMM_WORLD, &status);

MPI_Get_count( &status, MPI_CHAR, &count );

                     message[count]=0;    /* append a 0-byte to terminate string */

printf("Process %d: received this --> \"%s\"\n", rank, message);

fflush(stdout);

              }

       }

MPI_Finalize();

return 0;

}