Procedure

   void dafgsr_c  ( SpiceInt        handle,
                    SpiceInt        recno,
                    SpiceInt        begin,
                    SpiceInt        end,
                    SpiceDouble   * data,
                    SpiceBoolean  * found  )

Abstract

 
   Read a portion of the contents of a summary record in a DAF file. 
 

Required_Reading

 
   DAF 
 

Keywords

 
   FILES 
 

Brief_I/O

 
   Variable  I/O  Description 
   --------  ---  -------------------------------------------------- 
   handle     I   Handle of DAF. 
   recno      I   Record number. 
   begin      I   First word to read from record. 
   end        I   Last word to read from record. 
   data       O   Contents of record. 
   found      O   True if record is found. 
 

Detailed_Input

 
   handle      is the handle associated with a DAF. 
 
   recno       is the record number of a particular double precision 
               record within the DAF, whose contents are to be read. 
               DAF record numbers start at 1.
 
   begin       is the first word in the specified record to be 
               returned.  For compatibility with SPICELIB, word
               numbers range from 1 to 128.
 
   end         is the final word in the specified record to be 
               returned.  For compatibility with SPICELIB, word
               numbers range from 1 to 128.
 

Detailed_Output

 
   data        contains the specified portion (from `begin' to `end', 
               inclusive) of the specified record.

   found       is SPICETRUE when the specified record is found, and is 
               SPICEFALSE otherwise. 
 

Parameters

 
   None. 
 

Exceptions

 
   1) Bad values for `begin' and `end' (begin < 1, end < begin,
      etc.) are not signaled as errors, but result in the actions
      implied by the pseudo-code:
 
         for ( j = 0, i = max(1,begin);  i <= max(128,end);  i++, j++ )
         {
            data[j] =  buffered_DAF_record[i];
         }  
 
   2) If `handle' is invalid, the error will be diagnosed by
      routines called by this routine.
   

Files

 
   The input handle must refer to a DAF that is open for read or write
   access.
 

Particulars

 
   dafgsr_c checks the DAF record buffer to see if the requested 
   record can be returned without actually reading it from 
   external storage. If not, it reads the record and stores 
   it in the buffer, typically removing another record from 
   the buffer as a result. 
 
   Once in the buffer, the specified portion of the record is 
   returned.
 

Examples

 
   The following code fragment illustrates one way that dafgsr_c 
   and dafwdr_ can be used to update part of a summary record. 
   If the record does not yet exist, we can assume that it is 
   filled with zeros. 
 
      #include "SpiceUsr.h"
      #include "SpiceZfc.h"

      SpiceInt    size   = 128;
      SpiceInt    recno;
      SpiceInt    handle;
          .
          .
          .
      dafgsr_c ( handle, recno, 1, 128, drec, &found );
 
      if ( !found )
      {  
          cleard_ ( &size, drec );
      }
      
      for ( i = first;  i <= last;  i++ )
      {
          drec[i] = new_value[i];
      }
  
      dafwdr_ ( &handle, &recno, drec );

   Note that since only entire records may be written using dafwdr_, 
   the entire record needs to be read also. 
 

Restrictions

 
   None.
 

Literature_References

 
   None.

Author_and_Institution

 
   N.J. Bachman    (JPL)
   F.S. Turner     (JPL) 
 

Version

 
   -CSPICE Version 1.0.0, 17-JUN-2009 (NJB) (FST)

Index_Entries

 
   read daf summary record 
 

Link to routine dafgsr_c source file dafgsr_c.c