basic C program for MPI environment validation

Makefile

test: mpitest
	mpirun -np 2 ./mpitest

mpitest: mpitest.c
	mpicc mpitest.c -o mpitest

clean:
	rm mpitest

mpitest.c

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

int main(int argc, char** argv) {
    MPI_Init(NULL, NULL);
    int world_size;
    MPI_Comm_size(MPI_COMM_WORLD, &world_size);
    int world_rank;
    MPI_Comm_rank(MPI_COMM_WORLD, &world_rank);
    char processor_name[MPI_MAX_PROCESSOR_NAME];
    int name_len;
    MPI_Get_processor_name(processor_name, &name_len);
    printf("Hello world from processor %s, rank %d out of %d processors\n",
           processor_name, world_rank, world_size);
    MPI_Finalize();
}

Output:

$ make
mpicc test.c -o mpitest
mpirun -np 2 ./mpitest
Hello world from processor cobalt-mustang, rank 0 out of 2 processors
Hello world from processor cobalt-mustang, rank 1 out of 2 processors