fortran+MPIコーディング入門(1) プロセス並列の基本 ref: https://qiita.com/Bluepost59/items/5cce1174ac48367948bc

file0.txt

mpif90 -o smp01 smp01.f90

file1.txt

mpiexec -np 4 smp01

file3.txt

 I am            1 /           4
 I am            3 /           4
 I am            0 /           4
 I am            2 /           4

smp01.f90

program main
  implicit none

  include 'mpif.h'

  integer :: nnn
  integer :: me
  integer :: ierr

  call mpi_init(ierr)
  call mpi_comm_size(mpi_comm_world,nnn,ierr)
  call mpi_comm_rank(mpi_comm_world,me,ierr)

  write(6,*) "I am ",me,"/",nnn

  call mpi_finalize(ierr)

end program main