module link_module
type link
real :: n
type (link), pointer :: next
end type link
end module link_module

program ch2202_1
use link_module
implicit none
type (link), pointer :: root, current
integer :: i = 0
integer :: error = 0
integer :: io_stat_number = 0
integer :: blank_lines = 0
real, allocatable, dimension (:) :: x

  allocate (root)
  print *, ' type in some numbers'
  read (unit=*,fmt=*,iostat=io_stat_number) root%n
  if (io_stat_number>0) then
    error = error + 1
  else if (io_stat_number==-1) then
    nullify (root%next)
  else if (io_stat_number==-2) then
    blank_lines = blank_lines + 1
  else
    i = i + 1
    allocate (root%next)
  end if
  current => root
  do while (associated(current%next))
    current => current%next
    read (unit=*,fmt=*,iostat=io_stat_number) current%n
    if (io_stat_number>0) then
      error = error + 1
    else if (io_stat_number==-1) then
      nullify (current%next)
    else if (io_stat_number==-2) then
      blank_lines = blank_lines + 1
    else
      i = i + 1
      allocate (current%next)
    end if
  end do
  print *, i, ' items read'
  print *, blank_lines, ' blank lines'
  print *, error, ' items in error'
  allocate (x(1:i))
  i = 1
  current => root
  do while (associated(current%next))
    x(i) = current%n
    i = i + 1
    print *, current%n
    current => current%next
  end do
  print *, x
end program ch2202_1