program example4
      include 'mpif.h'
      integer BUFSIZE
      parameter (BUFSIZE = 4 + MPI_BSEND_OVERHEAD)
      byte buf(BUFSIZE)
      integer rank, ierr, ibufsize, rbuf
      integer status(MPI_STATUS_SIZE)
      call MPI_INIT(ierr)
      call MPI_COMM_RANK(MPI_COMM_WORLD, rank, ierr)
      if(rank .eq. 0) then
         call MPI_BUFFER_ATTACH(buf, BUFSIZE, ierr)
         call MPI_BSEND(rank, 1, MPI_INTEGER, 1, 5,
     &                  MPI_COMM_WORLD, ierr)
         call MPI_BUFFER_DETACH(buf, ibufsize, ierr)
      end if
      if(rank .eq. 1) then
         call MPI_RECV(rbuf, 1, MPI_INTEGER, 0, 5,
     &                 MPI_COMM_WORLD, status, ierr)
         print *, 'Process 1 received ', rbuf, ' from process ',
     &            status(MPI_SOURCE)
      end if
      call MPI_FINALIZE(ierr)
      end