Procedure

     DASIOD ( DAS, Fortran I/O, double precision )

     SUBROUTINE DASIOD ( ACTION, UNIT, RECNO, RECORD )

Abstract

     Perform Fortran reads and writes of DAS double precision records.
     This routine operates on DAS files having native binary format.

Required_Reading

     DAS

Keywords

     DAS
     FILES
     UTILITY

Declarations

     IMPLICIT NONE

     INTEGER               NWD
     PARAMETER           ( NWD = 128 )

     CHARACTER*(*)         ACTION
     INTEGER               UNIT
     INTEGER               RECNO
     DOUBLE PRECISION      RECORD ( NWD )

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     ACTION     I   Action to take (read or write).
     UNIT       I   Fortran unit connected to DAS file.
     RECNO      I   Number of record to read or write.
     RECORD    I-O  DAS double precision record.

Detailed_Input

     ACTION   is a character string specifying whether to read
              from or write to the specified DAS file. Possible
              values are:

                 'READ'
                 'WRITE'

              Case and leading or trailing blanks are not
              significant.


     UNIT     is the Fortran unit number connected to the DAS
              file that is to be read or written. Given the
              handle of the DAS file, the unit number can be
              obtained using ZZDDHHLU.

     RECNO    is the Fortran record number of the record to be
              read or written.

     RECORD   is a double precision array whose contents are to
              be written to record RECNO, if ACTION is WRITE.

Detailed_Output

     RECORD   is a double precision array whose contents are to
              be set equal to those of record RECNO, if ACTION
              is READ.

Parameters

     NWD      is the number of elements in a DAS double precision
              record.

Exceptions

     1)  If the value of ACTION is not recognized, the error
         SPICE(UNRECOGNIZEDACTION) is signaled.

     2)  If a Fortran read error occurs, the error
         SPICE(DASFILEREADFAILED) is signaled.

     3)  If a Fortran write error occurs, the error
         SPICE(DASFILEWRITEFAILED) is signaled.

Files

     See the description of the argument UNIT in $Detailed_Input.

Particulars

     This routine may be used to write to and read from DAS files
     having the native binary file format of the host system. The
     routine ZZDASGDR should be used to read double precision records
     from DAS files that may have either native or non-native format.

     Normally, routines outside of SPICELIB will not need to call this
     routine directly. Writes to DAS files should be performed using
     the DASADx and DASUDx routines; reads should be performed using
     the DASRDx routines.

     This routine centralizes I/O and the concomitant error handling
     for DAS double precision records.

     Although most DAS routines use file handles to identify DAS
     files, this routine uses Fortran logical units for this purpose.
     Using unit numbers allows the DASIOx routines to be called from
     any DAS routine, including entry points of DASFM.

Examples

     1)  Read and print to the screen double precision records
         number 10 through 20 from the DAS file designated by HANDLE.


            DOUBLE PRECISION      RECORD ( NWD )
                           .
                           .
                           .

            CALL ZZDDHHLU ( HANDLE, 'DAS', .FALSE., UNIT )
            CALL DASHFN   ( HANDLE, NAME )

            DO I = 1, 20

               CALL DASIOD ( 'READ', UNIT, 10, RECORD )

               LABEL = 'Contents of the # record in DAS file #: '

               CALL REPMOT ( LABEL,  '#',  I,  'L',   LABEL )
               CALL REPMC  ( LABEL,  '#',      NAME,  LABEL )

               WRITE (*,*) LABEL
               WRITE (*,*) ' '
               WRITE (*,*) RECORD

            END DO



     2)  Write the contents of the array RECORD to record number
         10 in the DAS file designated by HANDLE.


            DOUBLE PRECISION      RECORD ( NWD )

                           .
                           .
                           .

            CALL ZZDDHHLU ( HANDLE,  'DAS', .FALSE., UNIT   )
            CALL DASIOD   ( 'WRITE', UNIT,  10,      RECORD )

Restrictions

     1)  This routine may be used only on DAS files having
         the native binary file format of the host system.

Literature_References

     None.

Author_and_Institution

     N.J. Bachman       (JPL)
     J. Diaz del Rio    (ODC Space)
     W.L. Taber         (JPL)

Version

    SPICELIB Version 1.1.0, 12-AUG-2021 (JDR)

        Added IMPLICIT NONE statement.

        Edited the header to comply with NAIF standard.

    SPICELIB Version 1.0.1, 05-FEB-2015 (NJB)

        Header was updated to refer to ZZDDHHLU. $Restrictions section
        was updated.

    SPICELIB Version 1.0.0, 30-JUN-1992 (NJB) (WLT)