program main

c*********************************************************************72
c
cc MAIN is the main program for VERSION.
c
c  Discussion:
c
c    VERSION is a simple MPI test program that gets the version of MPI.
c
c    Get the version and subversion of MPI.
c
c  Modified:
c
c    09 January 2004
c
c  Author:
c
c    John Burkardt
c
c  Reference:
c
c    William Gropp, Ewing Lusk, Anthony Skjellum,
c    Using MPI: Portable Parallel Programming with the
c    Message-Passing Interface,
c    Second Edition,
c    MIT Press, 1999,
c    ISBN: 0262571323.
c

c
c  Define MPI symbols by invoking the Fortran77-style include file:
c
      include 'mpif.h'

      integer error
      integer master
      integer num_procs
      integer subversion
      integer version
      integer world_id

      master = 0
c
c  Initialize MPI.
c
      call MPI_Init ( error )
c
c  Get MPI version and subversion.
c
      call MPI_Get_version ( version, subversion )
c
c  Get the number of processes.
c
      call MPI_Comm_size ( MPI_COMM_WORLD, num_procs, error )
c
c  Get the individual process ID.
c
      call MPI_Comm_rank ( MPI_COMM_WORLD, world_id, error )
c
c  Print a message.
c
      if ( world_id .eq. master ) then
        write ( *, '(a)' ) ' '
        write ( *, '(a)' ) 'VERSION - Master process:'
        write ( *, '(a)' ) '  FORTRAN77 version'
        write ( *, '(a)' ) '  A simple MPI program.'
        write ( *, '(a)' ) ' '
        write ( *, '(a,i3)' ) '  The number of processes is ', 
     &     num_procs
        write ( *, '(a)' ) ' '
        write ( *, '(a,i3)' ) '  MPI version number is ', version
        write ( *, '(a,i3)' ) '  MPI subversion number is ', 
     &     subversion
      end if

      write ( *, '(a)' ) ' '
      write ( *, '(a,i3,a)' ) '  Process ', world_id, 
     &   ' says "Hello, world!"'

      if ( world_id .eq. master ) then
        write ( *, '(a)' ) ' '
        write ( *, '(a)' ) 'VERSION - Master process:'
        write ( *, '(a)' ) '  Normal end of execution: '
        write ( *, '(a)' ) '  "Goodbye, world!".'
      end if
c
c  Shut down MPI.
c
      call MPI_Finalize ( error )

      stop
      end