real32
real64
int32
int64
...

input_unit
output_unit
error_unit

iostat_end
iostat_eor

numeric_storage_size
character_storage_size
...

program learn_iso_fortran_env
  use, intrinsic :: iso_fortran_env
  implicit none
  print*, 'character_kinds        =', character_kinds
  print*, 'integer_kinds          =', integer_kinds
  print*, 'real_kinds             =', real_kinds
  print*, 'int32                  = ',int32
  print*, 'int64                  = ',int64
  print*, 'real32                 = ',real32
  print*, 'real64                 = ',real64
  print*, 'input_unit             = ',input_unit
  print*, 'output_unit            = ',output_unit
  print*, 'error_unit             = ',error_unit
  print*, 'numeric_storage_size   = ',numeric_storage_size
  print*, 'character_storage_size = ',character_storage_size
  print*, 'file_storage_size      = ',file_storage_size
  print*, 'iostat_end             = ',iostat_end
  print*, 'iostat_eor             = ',iostat_eor
end program learn_iso_fortran_env