Index of Functions: A B C D E F G H I J K L M N O P Q R S T U V W X
Index Page dafopr_c

Table of contents

Procedure Abstract Required_Reading Keywords Brief_I/O Detailed_Input | Detailed_Output Parameters Exceptions Files Particulars Examples | Restrictions Literature_References Author_and_Institution Version Index_Entries

#### Procedure

       dafopr_c ( DAF, open for read )

       void dafopr_c ( ConstSpiceChar    * fname,
                       SpiceInt          * handle  )

#### Abstract

       Open a DAF for subsequent read requests.

#### Required_Reading

       DAF

#### Keywords

       DAF
       FILES

#### Brief_I/O

       VARIABLE  I/O  DESCRIPTION
       --------  ---  --------------------------------------------------
       fname      I   Name of DAF to be opened.
       handle     O   Handle assigned to DAF.

#### Detailed_Input

       fname       is the file name of a DAF to be opened for read
                   access.

#### Detailed_Output

       handle      is the file handle associated with the file. This
                   handle is used to identify the file in subsequent
                   calls to other DAF routines.

#### Parameters

       None.

#### Exceptions

       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, an error is signaled by a routine in the call
           tree of this routine.

       3)  If the specified file has already been opened by a non-DAF
           routine, an error is signaled by a routine in the call
           tree of this routine.

       4)  If the specified file cannot be opened without exceeding
           the maximum number of files, the error SPICE(DAFFTFULL)
           is signaled by a routine in the call tree of this routine.

       5)  If the attempt to read the file's file record fails, the error
           SPICE(FILEREADFAILED) is signaled by a routine in the call
           tree of this routine.

       6)  If the specified file is not a DAF file, an error is
           signaled by a routine in the call tree of this routine.

       7)  If no logical units are available, an error is
           signaled by a routine in the call tree of this routine.

       8)  If the file does not exist, an error is signaled by a routine
           in the call tree of this routine.

       9)  If an I/O error occurs in the process of opening the file,
           the error is signaled by a routine in the call tree of this
           routine.

       10) If the file name is blank or otherwise inappropriate,
           an error is signaled by a routine in the call tree of this
           routine.

       11) If the file was transferred improperly via FTP, an error is
           signaled by a routine in the call tree of this routine.

       12) If the file utilizes a binary file format that is not
           currently supported on this platform, an error is signaled by
           a routine in the call tree of this routine.

       13) If the `fname' input string pointer is null, the error
           SPICE(NULLPOINTER) is signaled.

       14) If the `fname' input string has zero length, the error
           SPICE(EMPTYSTRING) is signaled.

#### Files

       See argument `fname'.

#### Particulars

       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.

#### Examples

       The numerical results shown for these examples may differ across
       platforms. The results depend on the SPICE kernels used as
       input, the compiler and supporting libraries, and the machine
       specific arithmetic implementation.

       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 );
          }

       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.

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

             de421.bsp

          Example code begins here.

          /.
             Program dafopr_ex1
          ./
          #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: %d %d %d %d %d %d\n\n",
                           (int)ic[0], (int)ic[1], (int)ic[2],
                           (int)ic[3], (int)ic[4], (int)ic[5] );

                /.
                Check for another segment.
                ./
                daffna_c ( &found );
                }

             /.
             Safely close the DAF.
             ./
             dafcls_c ( handle  );

             return ( 0 );
             }

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

           Doubles: -3169195200.000000 1696852800.000000
          Integers: 1 0 1 2 641 310404

           Doubles: -3169195200.000000 1696852800.000000
          Integers: 2 0 1 2 310405 423048

           Doubles: -3169195200.000000 1696852800.000000
          Integers: 3 0 1 2 423049 567372

           Doubles: -3169195200.000000 1696852800.000000
          Integers: 4 0 1 2 567373 628976

           Doubles: -3169195200.000000 1696852800.000000
          Integers: 5 0 1 2 628977 674740

           Doubles: -3169195200.000000 1696852800.000000
          Integers: 6 0 1 2 674741 715224

           Doubles: -3169195200.000000 1696852800.000000
          Integers: 7 0 1 2 715225 750428

           Doubles: -3169195200.000000 1696852800.000000
          Integers: 8 0 1 2 750429 785632

           Doubles: -3169195200.000000 1696852800.000000
          Integers: 9 0 1 2 785633 820836

           Doubles: -3169195200.000000 1696852800.000000
          Integers: 10 0 1 2 820837 944040

           Doubles: -3169195200.000000 1696852800.000000
          Integers: 301 3 1 2 944041 1521324

           Doubles: -3169195200.000000 1696852800.000000
          Integers: 399 3 1 2 1521325 2098608

           Doubles: -3169195200.000000 1696852800.000000
          Integers: 199 1 1 2 2098609 2098620

           Doubles: -3169195200.000000 1696852800.000000
          Integers: 299 2 1 2 2098621 2098632

           Doubles: -3169195200.000000 1696852800.000000
          Integers: 499 4 1 2 2098633 2098644

          Note, the final entries in the integer array contain 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)  Files opened using this routine must be closed with dafcls_c.

#### Literature_References

       None.

#### Author_and_Institution

       N.J. Bachman        (JPL)
       J. Diaz del Rio     (ODC Space)
       K.R. Gehringer      (JPL)
       J.M. Lynch          (JPL)
       W.L. Taber          (JPL)
       I.M. Underwood      (JPL)
       E.D. Wright         (JPL)

#### Version

       -CSPICE Version 1.0.3, 10-AUG-2021 (JDR)

           Edited the header to comply with NAIF standard. Added -Restrictions
           section.

           Improved -Exceptions sections.

       -CSPICE Version 1.0.2, 28-JUN-2016 (EDW)

           Edit to Example code, SpiceInts output as ints using
           explicit casting.

       -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)

#### Index_Entries

       open DAF for read

#### Link to routine dafopr_c source file dafopr_c.c

    Fri Dec 31 18:41:03 2021