program ex0902
  implicit none
  character(len=20) :: string

  open(unit=10, file="test.txt")
  write(10,"(A20)") "Good morning." ! 寫到文件中
  rewind(10)
  read(10,"(A20)") string ! 從文件中讀出來(lái)
  write(*,"(A20)") string ! 寫到屏幕上

  stop
end