!**********************************************************************
 ! This file: http://ftp.aset.psu.edu/pub/ger/fortran/hdk/direct.f90
!  ROUTINE:   DIRECT.F90
!  PURPOSE:   To Demonstrate use of Fortran Direct Access.
!  COMPILERS: Compaq CVF, Lahey LF95, and Salford FTN95, AIX XLF90
!  CONTACT:   H. D. Knoble <hdkLESS at SPAM psu dot edu> 03/11/91
!**********************************************************************
!
!=======This program sequentially creates, then randomly reads and
!       displays a random set of records. It will work with
!       FORM='FORMATTED' and formatted WRITEs/READs or
!       FORM='UNFORMATTED' and unformatted WRITEs/READs.
!
      CHARACTER*40 LINE
      CHARACTER*21 fileid
      INTEGER IREC(10), lrecl, numrec, I
      DATA fileid/'DIRECT.DAT'/
      DATA lrecl/40/, numrec/15/
!--------IREC is the order (by record #) that records will be read.
      DATA IREC/9,8,7,6,5,4,3,2,1,15/
!--------See if the file exists. If not create it.
      WRITE(*,*) 'DIRECT FORTRAN Begin...'
!--------Preformat.
        WRITE(*,*) 'Preformatting file:',fileid
        OPEN(UNIT=90,FORM='FORMATTED',FILE=fileid,STATUS='UNKNOWN', &
        ACCESS='DIRECT',RECL=lrecl)
        DO I=1,numrec
          WRITE(LINE,3) I
    3     FORMAT('This is record number', I3)
          WRITE(90,'(A)',REC=I) LINE
        END DO
        CLOSE(UNIT=90)
      WRITE(*,*) 'Direct file is:',fileid
      WRITE(*,*) 'Direct access in "random" order...'
      WRITE(*,*) ' '
!--------Get the record length for this file.
      INQUIRE (FILE=fileid,RECL=lrecl)
      WRITE(*,*)'Record Length of DIRECT.DAT=',lrecl
      OPEN(UNIT=8, ACCESS='DIRECT', FILE=fileid, FORM='FORMATTED', &
           RECL=lrecl,STATUS='OLD')
!--------Read 10 records "randomly" and display those records.
      DO I=1,10
        READ(8,'(A)',REC=IREC(I)) LINE
        WRITE(*,5) IREC(I),LINE
    5   FORMAT(' Record#',I4,'->',A40)
      END DO
!--------Wrap up.
      WRITE(*,7)
    7 FORMAT(/' ** DIRECT demo all done **')
      STOP
      END