ファイルの行数をカウントするプログラム例

program count_lines
  implicit none
  character(1000) filename
  integer counter
  
  print *, 'Enter file name to count lines: '
  read '(A)', filename
  open(11,file=filename,status='old')
  counter = 0
  do
    read(11,'()',end=100)
    counter = counter + 1
  end do
100 close(11)
  print *,'Number of lines is',counter
end program count_lines