Procedure

     DAFFNA ( DAF, find next array )

     ENTRY DAFFNA ( FOUND )

Abstract

     Find the next (forward) array in the current DAF.

Required_Reading

     DAF

Keywords

     FILES

Declarations

    LOGICAL               FOUND

Brief_I/O

     VARIABLE  I/O  DESCRIPTION
     --------  ---  --------------------------------------------------
     FOUND      O   .TRUE. if an array was found.

Detailed_Input

     None.

Detailed_Output

     FOUND    is .TRUE. if an array was found, and is .FALSE. if,
              when this routine is called, the current array is
              the tail of the array list. (Recall that the
              arrays in a DAF may be viewed as a doubly linked
              list, with the tail being the last array in the file.)

Parameters

     None.

Exceptions

     1)  If this routine is called before a search is begun, the
         error SPICE(DAFNOSEARCH) is signaled.

     2)  If the DAF to be searched has actually been closed, an error
         is signaled by a routine in the call tree of this routine.

     3)  If the end of the array list has already been reached when
         this routine is called, this routine has no effect.

     4)  If the summary record of the next array (aka "segment") in
         the DAF file cannot be read, the error SPICE(RECORDNOTFOUND)
         is signaled.

Files

     None.

Particulars

     See DAFFA.

Examples

     1) See DAFFA.

     2) Use a simple routine to output the double precision and
        integer values stored in an SPK's segment's descriptors. This
        function opens a DAF for read, performs a forwards search for
        the DAF arrays, prints the segment descriptor for each array
        found, then closes the DAF.

        Use the SPK kernel below as input DAF file for the program.

           de421.bsp


        Example code begins here.


              PROGRAM DAFFNA_EX1
              IMPLICIT NONE

        C
        C     Define the summary parameters appropriate
        C     for an SPK file.
        C
              INTEGER               MAXSUM
              PARAMETER           ( MAXSUM = 125 )

              INTEGER               ND
              PARAMETER           ( ND = 2 )

              INTEGER               NI
              PARAMETER           ( NI = 6 )

        C
        C     Local variables.
        C
              CHARACTER*(32)        KERNEL

              DOUBLE PRECISION      DC ( ND     )
              DOUBLE PRECISION      SUM( MAXSUM )

              INTEGER               HANDLE
              INTEGER               IC( NI )

              LOGICAL               FOUND


        C
        C     Open a DAF for read. Return a HANDLE referring to the
        C     file.
        C
              KERNEL = 'de421.bsp'
              CALL DAFOPR ( KERNEL, HANDLE )

        C
        C     Begin a forward search on the file.
        C
              CALL DAFBFS ( HANDLE )

        C
        C     Search until a DAF array is found.
        C
              CALL DAFFNA ( FOUND )

        C
        C     Loop while the search finds subsequent DAF arrays.
        C
              DO WHILE ( FOUND )

                 CALL DAFGS ( SUM )
                 CALL DAFUS ( SUM, ND, NI, DC, IC )

                 WRITE(*,*)                'Doubles:', DC(1:ND)
                 WRITE(*, FMT='(A,6I9)' ) 'Integers:', IC(1:NI)

        C
        C        Check for another segment.
        C
                 CALL DAFFNA ( FOUND )

              END DO

        C
        C     Safely close the DAF.
        C
              CALL DAFCLS ( HANDLE )

              END


        When this program was executed on a Mac/Intel/gfortran/64-bit
        platform, the output was:


         Doubles:  -3169195200.0000000        1696852800.0000000
        Integers:        1        0        1        2      641   310404
         Doubles:  -3169195200.0000000        1696852800.0000000
        Integers:        2        0        1        2   310405   423048
         Doubles:  -3169195200.0000000        1696852800.0000000
        Integers:        3        0        1        2   423049   567372
         Doubles:  -3169195200.0000000        1696852800.0000000
        Integers:        4        0        1        2   567373   628976
         Doubles:  -3169195200.0000000        1696852800.0000000
        Integers:        5        0        1        2   628977   674740
         Doubles:  -3169195200.0000000        1696852800.0000000
        Integers:        6        0        1        2   674741   715224
         Doubles:  -3169195200.0000000        1696852800.0000000
        Integers:        7        0        1        2   715225   750428
         Doubles:  -3169195200.0000000        1696852800.0000000
        Integers:        8        0        1        2   750429   785632
         Doubles:  -3169195200.0000000        1696852800.0000000
        Integers:        9        0        1        2   785633   820836
         Doubles:  -3169195200.0000000        1696852800.0000000
        Integers:       10        0        1        2   820837   944040
         Doubles:  -3169195200.0000000        1696852800.0000000
        Integers:      301        3        1        2   944041  1521324
         Doubles:  -3169195200.0000000        1696852800.0000000
        Integers:      399        3        1        2  1521325  2098608
         Doubles:  -3169195200.0000000        1696852800.0000000
        Integers:      199        1        1        2  2098609  2098620
         Doubles:  -3169195200.0000000        1696852800.0000000
        Integers:      299        2        1        2  2098621  2098632
         Doubles:  -3169195200.0000000        1696852800.0000000
        Integers:      499        4        1        2  2098633  2098644


        Note, the final entries in the integer array contains the
        segment start/end indexes. The output indicates the search
        proceeded from the start of the file (low value index) towards
        the end (high value index).

Restrictions

     1)  Calls that do or may change DAF addresses of DAF summaries,
         names, or data of a given DAF file should not be made during
         a search of that file initiated by either DAFBFS or DAFBBS.
         No such changes should be made between the start of a search
         and calls to any entry point that reads or writes to the
         summary of the "current array" found by that search, or
         that returns a "found" flag indicating whether the current
         array exists.

         Changing the size of the comment area while a search is in
         progress can invalidate record numbers stored in local data
         structures of this routine. This can cause corrupted array
         summaries and names to be returned upon read access and file
         corruption to occur upon write access.

         Adding arrays (aka "segments") while either a forward or
         backward search is in progress can cause the search to miss
         the new segments.

Literature_References

     None.

Author_and_Institution

     N.J. Bachman       (JPL)
     J. Diaz del Rio    (ODC Space)
     H.A. Neilan        (JPL)
     W.L. Taber         (JPL)
     I.M. Underwood     (JPL)
     E.D. Wright        (JPL)

Version

    SPICELIB Version 2.1.1, 26-OCT-2021 (JDR) (NJB)

        Edited the header to comply with NAIF standard.
        Added undeclared variables to code example.

        Updated $Restrictions section.

    SPICELIB Version 2.1.0, 10-OCT-2012 (EDW)

        Added a functional code example to the $Examples section.

        Added check on value of "found" boolean returned from
        DAFGSR calls. Failure to check this value can cause an
        infinite loop during segment searches on damaged SPKs.

        Eliminated unneeded $Revisions section.

        Removed the obsolete Reference citation to "NAIF
        Document 167.0."

    SPICELIB Version 2.0.1, 10-MAR-1992 (WLT)

        Comment section for permuted index source lines was added
        following the header.

    SPICELIB Version 2.0.0, 04-SEP-1991 (NJB) (WLT)

        Updated to support simultaneous searches of multiple DAFs.

        This routine now operates on the current DAF---the one at
        the head of the active list. All saved state variables
        used by this routine are now part of the state table, or
        its associated set of pointers.

    SPICELIB Version 1.0.1, 22-MAR-1990 (HAN)

        Literature references added to the header.

    SPICELIB Version 1.0.0, 31-JAN-1990 (IMU)