CSPICE_DLABFS begins a forward segment search in a DLA file.
handle the DAS integer handle associated with the file to be
searched. This handle is used to identify the file in
subsequent calls to other DLA or DAS routines.
[1,1] = size(handle); int32 = class(handle)
[dladsc, found] = cspice_dlabfs( handle )
dladsc the descriptor of the first DLA segment in the file
associated with `handle'. `dladsc' is valid only if the
output argument `found' is true.
[SPICE_DLA_DSCSIZ,1] = size(dladsc)
int32 = class(dladsc)
found a logical flag indicating whether a segment was found.
`found' has the value true if a segment was found;
otherwise `found' is false.
[1,1] = size(found); logical = class(found)
Any numerical results shown for this example may differ between
platforms as the results depend on the SPICE kernels used as input
and the machine specific arithmetic implementation.
Open a DLA file for read access, traverse the segment
list from front to back, and display segment address
and size attributes.
function dlab_t( dla )
SPICE_DLA_BWDIDX = 1;
SPICE_DLA_FWDIDX = 2;
SPICE_DLA_IBSIDX = 3;
SPICE_DLA_ISZIDX = 4;
SPICE_DLA_DBSIDX = 5;
SPICE_DLA_DSZIDX = 6;
SPICE_DLA_CBSIDX = 7;
SPICE_DLA_CSZIDX = 8;
% Open the DSK file for read access.
% We use the DAS-level interface for
% this function.
handle = cspice_dasopr( dla );
% Begin a forward search through the
% kernel, treating the file as a DLA.
% In this example, it's a very short
segno = 1;
[dladsc, found] = cspice_dlabfs( handle );
% Display the contents of the current segment
fprintf('Segment number = %d\n', segno )
fprintf(' Backward segment pointer = %d\n', ...
fprintf(' Forward segment pointer = %d\n', ...
fprintf(' Integer component base address = %d\n', ...
fprintf(' Integer component size = %d\n', ...
fprintf(' D.p. component base address = %d\n', ...
fprintf(' D.p. component size = %d\n', ...
fprintf(' Character component base address = %d\n', ...
fprintf(' Character component size = %d\n', ...
% Find the next segment.
current = dladsc;
segno = segno + 1;
[dladsc, found] = cspice_dlafns( handle, current );
% Close file.
cspice_dascls( handle )
>> dlab_t( 'phobos_3_3.bds' )
Segment number = 1
Backward segment pointer = -1
Forward segment pointer = -1
Integer component base address = 11
Integer component size = 3311271
D.p. component base address = 0
D.p. component size = 494554
Character component base address = 0
Character component size = 0
DLA files are built using the DAS low-level format; DLA files are
a specialized type of DAS file in which data are organized as a
doubly linked list of segments. Each segment's data belong to
contiguous components of character, double precision, and integer
This routine supports forward traversal of a DLA file's segment
list. Note that it is not necessary to call this routine to
conduct a forward traversal; all that is necessary is to have
access to the first descriptor in the file, which this routine
For important details concerning this module's function, please
refer to the CSPICE routine dlabfs_c.
-Mice Version 1.0.0, 05-MAY-2014, NJB, EDW (JPL)
begin forward search in dla file