MPIHelloWorld

From Parawiki

MPIHelloWorld.c

//compilation:
//$ mpicc -o program MPIHelloWorld.c
//$ mpirun -np number_of_processes program
//If you want to use multiple processors you have to use lamboot before! 
//if mpi.h cannot be found by the compiler, try to locate mpi.h:
//open a terminal and: $ locate mpi.h
//and then include by giving the whole path to mpi.h
#include <stdio.h>
#include "mpi.h" 
int main(int argc, char* argv[]){
	int rank, size;		//process rank and number of processes
    
	MPI_Init(&argc, &argv); //MPI initialize
	
	MPI_Comm_size(MPI_COMM_WORLD, &size);
	MPI_Comm_rank(MPI_COMM_WORLD, &rank);
	
	printf("Hello world from process %d of %d\n", rank, size);
    
	MPI_Finalize();		//MPI finalize
	return 0;
}