Procedure

     DASCUD ( DAS, create or update directories )

     SUBROUTINE DASCUD ( HANDLE, TYPE, NWORDS )

Abstract

     Create or update directories in a DAS file to reflect addition
     of a specified number of words of a specified data type.

Required_Reading

     DAS

Keywords

     DAS
     FILES
     UTILITY

Declarations

     IMPLICIT NONE

     INTEGER               HANDLE
     INTEGER               TYPE
     INTEGER               NWORDS

     INTEGER               CHAR
     PARAMETER           ( CHAR   =  1  )

     INTEGER               DP
     PARAMETER           ( DP     =  2  )

     INTEGER               INT
     PARAMETER           ( INT    =  3  )

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     HANDLE     I   DAS file handle.
     TYPE       I   Data type specifier.
     NWORDS     I   Number of words of data being added.
     CHAR       P   Parameter indicating character data type.
     DP         P   Parameter indicating double precision data type.
     INT        P   Parameter indicating integer data type.

Detailed_Input

     HANDLE   is the file handle of a DAS file open for writing.

     TYPE     is a data type specifier. TYPE may be any of
              the parameters

                 CHAR
                 DP
                 INT

              which indicate `character', `double precision',
              and `integer' respectively.

     NWORDS   is the number of words of data of the data type
              indicated by TYPE whose addition to the indicated
              DAS file is to be accounted for.

Detailed_Output

     None. See $Particulars for a description of the action of this
     routine.

Parameters

     CHAR,
     DP,
     INT      are data type specifiers which indicate
              `character', `double precision', and `integer'
              respectively. These parameters are used in
              all DAS routines that require a data type
              specifier as input.

Exceptions

     1)  If the input handle is invalid, an error is signaled by a
         routine in the call tree of this routine.

     2)  If TYPE is not recognized, the error SPICE(DASINVALIDTYPE)
         is signaled.

     3)  If NWORDS is negative, the error SPICE(VALUEOUTOFRANGE) is
         signaled.

Files

     None.

Particulars

     This routine operates by side effects: the directories in the
     indicated DAS file will be updated to reflect the addition of
     the indicated number of words of the specified data type.
     If necessary, a new directory record will be added to the file
     to hold a new cluster descriptor.

     In addition, the file summary for the indicated DAS file will be
     updated with the new values of the descriptor location and last
     logical address of the indicated type, as well as with the new
     value of the free record pointer.

     This routine is used by the DASADx routines: after each data
     addition, they call this routine to update the directories of the
     affected DAS file.

     Normally, there will be no need for routines outside of SPICELIB
     to call this routine directly. To add data to or update a DAS
     file, the DASADx and DASUDx routines should be used; these
     routines take care of directory creation and updates.

Examples

     1)  Update directories after writing N integer words to a
         DAS file designated by HANDLE:

             CALL DASCUD ( HANDLE, INT, N )

Restrictions

     1)  This routine is intended for use by the SPICELIB DAS routines.
         Non-SPICELIB software normally will not need to call this
         routine.

Literature_References

     None.

Author_and_Institution

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

Version

    SPICELIB Version 1.5.0, 13-AUG-2021 (JDR)

        Added IMPLICIT NONE statement.

        Edited the header to comply with NAIF standard.

    SPICELIB Version 1.4.0, 07-AUG-2006 (NJB)

        Bug fix: added initialization of variable LTYPE to support
                 operation under the Macintosh Intel Fortran
                 compiler. Note that this bug did not affect
                 operation of this routine on other platforms.

    SPICELIB Version 1.3.0, 16-JAN-2003 (NJB)

        Bug fix: fixed previous bug fix.

    SPICELIB Version 1.2.0, 10-DEC-2002 (NJB)

        Bug fix: now a new, empty directory record with valid
        backward and forward pointers is written immediately
        when it is created.

    SPICELIB Version 1.1.1, 19-DEC-1995 (NJB)

        Corrected title of permuted index entry section.

    SPICELIB Version 1.0.1, 26-OCT-1993 (KRG)

        Removed references to specific DAS file open routines in the
        $Detailed_Input section of the header. This was done in order
        to minimize documentation changes if the DAS open routines ever
        change.

        Removed an unused variable.

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