void dafopr_c ( ConstSpiceChar * fname,
SpiceInt * handle )
Open a DAF for subsequent read requests.
DAF
DAF
FILES
Variable I/O Description
-------- --- --------------------------------------------------
fname I Name of DAF to be opened.
handle O Handle assigned to DAF.
fname is the file name of a DAF to be opened for read
access.
handle is the file handle associated with the file. This
handle is used to identify the file in subsequent
calls to other DAF routines.
None.
1) If the specified file has already been opened for read
access, the handle already associated with the file is
returned.
2) If the specified file has already been opened for write
access, the error SPICE(DAFRWCONFLICT) is signaled.
3) If the specified file has already been opened by a non-DAF
routine, the error SPICE(DAFIMPROPOPEN) is signaled.
4) If the specified file cannot be opened without exceeding
the maximum number of files, the error SPICE(DAFFTFULL)
is signaled.
5) If (for some reason) the file cannot be opened properly,
the error SPICE(DAFOPENFAIL) is signaled.
6) If the attempt to read the file's ID word fails, the error
SPICE(FILEREADFAILED) will be signaled.
7) If the specified file is not a DAF file, as indicated by the
file's ID word, the error SPICE(NOTADAFFILE) is signaled.
8) If no logical units are available, the error will be
signaled by routines called by this routine.
9) If the file does not exist, the error SPICE(FILEDOESNOTEXIST)
is signaled.
10) If the INQUIRE fails, the error SPICE(INQUIREFAILED)
is signaled.
11) If the file record cannot (for some reason) be read,
the error SPICE(DAFFRNOTFOUND) is signaled.
12) If the file name is blank, the error SPICE(BLANKFILENAME)
is signaled.
See argument fname.
Most DAFs require only read access. If you do not need to
change the contents of a file, you should open it with dafopr_c.
Example (1):
In the following code fragment, dafopr_c is used to open a file,
which is then searched for DAFs containing data for a particular
object.
#include "SpiceUsr.h"
.
.
.
dafopr_c ( fname, &handle );
dafbfs_c ( handle );
daffna_c ( &found );
while ( found )
{
dafgs_c ( sum );
dafus_c ( sum, ND, NI, dc, ic );
if ( ic[0] == target_object )
{
.
.
.
}
daffna_c ( &found );
}
Example (2):
Use a simple routine to output the double precision and integer
values stored in an SPK's segments descriptors. This function
opens a DAF for read, performs a forwards search for the DAF
arrays, prints segments description for each array found, then
closes the DAF.
#include <stdio.h>
#include "SpiceUsr.h"
int main()
{
/.
Local constants
./
/.
Define the summary parameters appropriate
for an SPK file.
./
#define ND 2
#define NI 6
#define MAXSUM 125
SpiceInt ic [ NI ];
SpiceInt handle;
SpiceDouble dc [ ND ];
SpiceDouble sum [ MAXSUM ];
SpiceChar * kernel = "de421.bsp";
SpiceBoolean found;
/.
Open a DAF for read. Return a handle referring to the file.
./
dafopr_c ( kernel, &handle );
/.
Begin a forward search on the file.
./
dafbfs_c ( handle );
/.
Search until a DAF array is found.
./
daffna_c ( &found );
/.
Loop while the search finds subsequent DAF arrays.
./
while ( found )
{
dafgs_c ( sum );
dafus_c ( sum, ND, NI, dc, ic );
printf( " Doubles: %f %f \n", dc[0], dc[1] );
printf( "Integers: %ld %ld %ld %ld %ld %ld\n\n",
ic[0], ic[1], ic[2], ic[3], ic[4], ic[5] );
/.
Check for another segment.
./
daffna_c ( &found );
}
/.
Safely close the DAF.
./
dafcls_c ( handle );
return ( 0 );
}
The program outputs:
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).
None.
None.
N.J. Bachman (JPL)
K.R. Gehringer (JPL)
J.M. Lynch (JPL)
W.L. Taber (JPL)
I.M. Underwood (JPL)
-CSPICE Version 1.0.1, 10-OCT-2012 (EDW)
Added a functional code example to the Examples section.
Removed the obsolete Reference citation to "NAIF
Document 167.0."
-CSPICE Version 1.0.0, 01-AUG-1999 (NJB) (KRG) (JML) (WLT) (IMU)
open daf for read
Link to routine dafopr_c source file dafopr_c.c
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