native_endianness.f

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      module native_endianness


 use kinds, only: i_byte,i_long
 implicit none

 private

 public byte_swap
 public is_little_endian

 logical byte_swap

 contains

 logical function is_little_endian()

   implicit none

   integer(i_byte) :: i1
   integer(i_long) :: i2

   i1 = 1
   i2 = 0
   i2 = transfer(i1,i2)

   is_little_endian = (i1 == i2)

 end function is_little_endian

 end module native_endianness

!----------------------------------------------------------------------
! convert 4-byte integer scalar from big-endian to native-endian
!----------------------------------------------------------------------

 subroutine to_native_endianness_i4(i4,num)

 use kinds, only: i_byte,i_long,i_llong
 implicit none

 integer(i_llong), intent(in) :: num
 integer(i_long), intent(inout) :: i4(num)

 integer(i_byte), dimension(4) :: byte_arr, byte_arr_tmp
 integer(i_long) :: i,n

 do n=1,num
    byte_arr_tmp = transfer(i4(n), byte_arr)
    byte_arr(1)=byte_arr_tmp(4)
    byte_arr(2)=byte_arr_tmp(3)
    byte_arr(3)=byte_arr_tmp(2)
    byte_arr(4)=byte_arr_tmp(1)
    i4(n) = transfer(byte_arr, i4(n))
 end do

 return

 end subroutine to_native_endianness_i4