!***********************************************************************************************************************************
!
!                            E N D I A N
!
!  Program:      ENDIAN
!
!  Programmer:   David G. Simpson
!                NASA Goddard Space Flight Center
!                Greenbelt, Maryland  20771
!
!  Date:         February 18, 2005
!
!  Language:     Fortran-90
!
!  Version:      1.00a
!
!  Description:  Print whether the computer on which this program is run
!                stores numbers in little-endian or big-endian order.
!
!***********************************************************************************************************************************

      PROGRAM ENDIAN

      IMPLICIT NONE

      LOGICAL :: LITTLE_ENDIAN

!-----------------------------------------------------------------------------------------------------------------------------------

      IF (LITTLE_ENDIAN()) THEN
         WRITE (UNIT=*, FMT='(/A)') ' Little endian.'
      ELSE
         WRITE (UNIT=*, FMT='(/A)') ' Big endian.'
      END IF

      STOP

      END PROGRAM ENDIAN




!***********************************************************************************************************************************
!  LITTLE_ENDIAN
!
!  Return .TRUE. for a little-endian computer, .FALSE. for big-endian.
!***********************************************************************************************************************************

      FUNCTION LITTLE_ENDIAN () RESULT (FLAG)

      IMPLICIT NONE

      LOGICAL :: FLAG

      INTEGER(KIND=1), DIMENSION(2) :: IARR                                         ! array of two 1-byte integers
      INTEGER(KIND=2) :: S                                                          ! scalar 2-byte integer

      S = 4660                                                                      ! set scalar to hex 1234
      IARR = TRANSFER (S,IARR)                                                      ! transfer to IARR

      IF (IARR(1) .EQ. 52) THEN                                                     ! if element 1 of IARR is hex 34..
         FLAG = .TRUE.                                                              ! ..then little endian
      ELSE
         FLAG = .FALSE.                                                             ! else big endian
      END IF

      RETURN

      END FUNCTION LITTLE_ENDIAN