Procedure

     DASIOC ( DAS, Fortran I/O, character )

     SUBROUTINE DASIOC ( ACTION, UNIT, RECNO, RECORD )

Abstract

     Perform Fortran reads and writes of DAS character records.

Required_Reading

     DAS

Keywords

     DAS
     FILES
     UTILITY

Declarations

     IMPLICIT NONE

     INTEGER               NWC
     PARAMETER           ( NWC = 1024 )

     CHARACTER*(*)         ACTION
     INTEGER               UNIT
     INTEGER               RECNO
     CHARACTER*(NWC)       RECORD

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 character 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 character array whose contents are to be
              written to record RECNO, if ACTION is WRITE.

Detailed_Output

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

Parameters

     NWC      is the number of characters in a DAS character
              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

     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 routines centralizes I/O and the concomitant error handling
     for DAS character 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.  (DASFM
     contains as entry points the routines DASHLU and DASLUH, which
     map between handles and unit numbers.)

Examples

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

            CHARACTER*(NWC)       RECORD

                           .
                           .
                           .

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

            DO I = 1, 20

               CALL DASIOC ( '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 string RECORD to record number
         10 in the DAS file designated by HANDLE.


            CHARACTER*(NWC)       RECORD

                           .
                           .
                           .

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

Restrictions

     None.

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.

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