Procedure

     DASURC ( DAS, update record, character )

     ENTRY DASURC ( HANDLE, RECNO, FIRST, LAST, DATAC )

Abstract

     Update DAS character physical records.

Required_Reading

     DAS

Keywords

     ASSIGNMENT
     DAS
     FILES

Declarations

    INTEGER               HANDLE
    INTEGER               RECNO
    INTEGER               FIRST
    INTEGER               LAST
    CHARACTER*(*)         DATAC

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     HANDLE     I   Handle of DAS file.
     RECNO      I   Record number.
     FIRST,
     LAST       I   First and last indices of range within record.
     DATAC      I   Character data to write to record.
     BUFSZC     P   Number of records in the character record buffer.
     NWC        P   Number of characters in a single DAS char. record.

Detailed_Input

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

     RECNO    is the number of a record in a DAS file.

     FIRST,
     LAST     are the first and last indices of a range of
              elements to be updated in the indicated record.
              The record contains NWC characters; these have
              indices ranging from 1 to NWC.

     DATAC    is a character string to be written to elements
              FIRST through LAST of the specified record. The
              character DATAC(1:1) is placed in record element
              FIRST, the character DATAC(2) is placed in record
              element FIRST+1, and so on; the character
              DATAC(LAST-FIRST+1) is placed in the record element
              LAST.

Detailed_Output

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

Parameters

     NWC      is the number of characters in a single DAS record
              containing characters.

     BUFSZC   is the number of records in the character record
              buffer.

Exceptions

     1)  This routine may be used to update only records that have
         already been written by DASWRC or that already exist in the
         file designated by HANDLE. Attempting to update a record
         that hasn't yet been written will cause the read operation
         performed by this routine to fail.

         If a read operation attempted by this routine fails for this
         or any other reason, an error is signaled by a routine in the
         call tree of this routine. The indicated record will not be
         modified.

     2)  If a write operation attempted by this routine fails, an error
         is signaled by a routine in the call tree of this routine. The
         status of the DAS file written to is uncertain in this case.
         Note that the file written to may be different than the file
         designated by HANDLE if multiple DAS files are open for
         writing.

     3)  If the input file handle is invalid, an error is signaled by a
         routine in the call tree of this routine. The indicated record
         will not be modified.

     4)  If FIRST or LAST is not in the range [1, NWC], the error
         SPICE(INDEXOUTOFRANGE) is signaled. The indicated
         record will not be modified.

     5)  If FIRST > LAST, this routine will return without modifying
         the indicated record.

Files

     See the description of the argument HANDLE in $Detailed_Input.

Particulars

     Routines outside of SPICELIB will normally have no need to call
     this routine.

     This routine can be used to update any existing record in a DAS
     file that is open for writing, or any record that has been
     `written' by DASWRC, whether or not that record has yet been
     physically written to the file it belongs to. Records that have
     never been written cannot be updated.

     Because the DAS system buffers records that are written, multiple
     updates of parts of a record can be made without incurring a
     large number of file reads and writes.

     Any buffered character record can be updated with this routine.
     In particular, records that have been written to the DAS character
     record buffer but have not yet been written out to the DAS file
     they're intended to go to ARE visible to this routine.

     This routine should be used to update only records that contain
     character data.

Examples

     1)  Update the 10th through 100th characters in record number 9
         in a DAS file designated by HANDLE.

             CHARACTER*(100)       DATAC

                         .
                         .
                         .

             DATAC = 'The first 91 characters of this string, '      //
            .        'including trailing blanks, will be written '   //
            .        'to the indicated DAS file.'

             CALL DASURC ( HANDLE, 9, 10, 100, DATAC )

Restrictions

     None.

Literature_References

     None.

Author_and_Institution

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

Version

    SPICELIB Version 2.0.1, 22-FEB-2021 (JDR)

        Edited the header to comply with NAIF standard.

    SPICELIB Version 2.0.0, 05-FEB-2015 (NJB)

        Upgraded to support handle manager integration.

    SPICELIB Version 1.0.3, 10-FEB-2014 (BVS)

        Added description of NWC to the $Parameters and $Brief_I/O
        sections of the header.

    SPICELIB Version 1.0.2, 03-NOV-1995 (NJB)

        Removed weird spaces from ENTRY statement.

    SPICELIB Version 1.0.1, 28-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.

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