read_shared.f90

        program main
        use mpi
        integer fh, i
        integer ierr
        integer wrank, wsize
        character *(100) filename
        integer status(MPI_STATUS_SIZE)
        integer buf
        call MPI_Init( ierr )
        call mpi_comm_rank( MPI_COMM_WORLD, wrank, ierr )
        call mpi_comm_size( MPI_COMM_WORLD, wsize, ierr )
	filename = "iotest.txt"
	call mpi_file_open( MPI_COMM_WORLD, filename, MPI_MODE_RDWR +       &
& MPI_MODE_CREATE, MPI_INFO_NULL, fh, ierr )

	do i=1, 4000
	    call mpi_file_read_shared( fh, buf, 1, MPI_INTEGER,   &
& status, ierr )
	enddo

	call mpi_file_close( fh, ierr )
	call mpi_barrier( MPI_COMM_WORLD, ierr )
        call mpi_finalize( ierr )
        end