Check intent of automatic sized character arrays

[christophermaynard]

Automatic sized arrays for characters can be used in Fortran, especially for subroutine arguments.

subroutine file_reader(filename)
  implicit none
character(*), intent(in) :: filename`

If they are intent(in) then there is no danger of scribbling over some other memory by writing back to the character array with data bigger than the array. intent(out) makes little sense and is hopefully not allowed by compilers. intent(inout) is potentially dangerous, In summary, intent(in) only is allowed.