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dafcs_c
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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

   void dafcs_c ( SpiceInt handle ) 

Abstract

 
   Select a DAF that already has a search in progress as the 
   one to continue searching. 
 

Required_Reading

 
   DAF 
 

Keywords

 
   FILES 
 

Brief_I/O

 
   Variable  I/O  Description 
   --------  ---  -------------------------------------------------- 
   handle     I   Handle of DAF to continue searching. 
 

Detailed_Input

 
   handle         is the handle of a DAF in which either a forward 
                  or backward search has already been started by 
                  dafbfs_c or dafbbs_c.  The DAF may be open for read 
                  or write access. 
 

Detailed_Output

 
   None. 
 

Parameters

 
   None. 
 

Exceptions

 
   1)  If the input handle is invalid, the error will be diagnosed 
       by routines called by this routine. 
 
   2)  If this routine is called when no search is in progress in the 
       the current DAF, the error SPICE(DAFNOSEARCH) is signalled. 
 

Files

 
   None. 
 

Particulars

 
   dafcs_c supports simultaneous searching of multiple DAFs.  In
   applications that use this capability, dafcs_c should be called
   prior to each call to daffna_c, daffpa_c, dafgn_c, or dafgs_c to
   specify which DAF is to be acted upon.
 
   The DAF search routines are:

      dafbfs_c       Begin forward search.
      daffna         Find next array.

      dafbbs_c       Begin backward search.
      daffpa_c       Find previous array.

      dafgs_c        Get summary.
      dafgn_c        Get name.
      dafgh_c        Get handle.

      dafcs_c        Continue search.

   The main function of these entry points is to allow the
   contents of any DAF to be examined on an array-by-array
   basis.

   Conceptually, the arrays in a DAF form a doubly linked list,
   which can be searched in either of two directions: forward or
   backward. It is possible to search multiple DAFs simultaneously.

   dafbfs_c (begin forward search) and daffna are used to search the
   arrays in a DAF in forward order.  In applications that search a
   single DAF at a time, the normal usage is

      dafbfs_c ( handle );
      daffna_c ( &found );

      while ( found )
      {
         dafgs_c ( sum  );
         dafgn_c ( name );
          .
          .

         daffna_c ( &found );
      }


   dafbbs_c (begin backward search) and daffpa_c are used to search the
   arrays in a DAF in backward order.  In applications that search
   a single DAF at a time, the normal usage is

      dafbbs_c ( handle );
      daffpa_c ( &found );

      while ( found )
      {
         dafgs_c ( sum  );
         dafgn_c ( name );
          .
          .

         daffpa_c ( &found );
      }


   In applications that conduct multiple searches simultaneously,
   the above usage must be modified to specify the handle of the
   file to operate on, in any case where the file may not be the
   last one specified by dafbfs_c or dafbbs_c.  The routine dafcs_c
   (DAF, continue search) is used for this purpose.  Below, we
   give an example of an interleaved search of two files specified
   by the handles handl1 and handl2.  The directions of searches
   in different DAFs are independent; here we conduct a forward
   search on one file and a backward search on the other.
   Throughout, we use dafcs to specify which file to operate on,
   before calling daffna_c, daffpa_c, dafgs_c, or dafgn_c.


      dafbfs_c ( handl1 );
      dafbbs_c ( handl2 );

      dafcs_c  ( handl1  );
      daffna_c ( &found1 );

      dafcs_c  ( handl2  );
      daffpa_c ( &found2 );

      while ( found1 || found2 )
      {
         if ( found1 )  
         {
            dafcs_c ( handl1 );
            dafgs_c ( sum    );
            dafgn_c ( name   );
             .
             .
            dafcs_c  ( &handl1 );
            daffna_c ( &found1 );
         }

         if ( found2 )  
         {
            dafcs_c ( handl2 );
            dafgs_c ( sum    );
            dafgn_c ( name   );
             .
             .
            dafcs_c  ( handl2  );
            daffpa_c ( &found2 );
         }
      }


   At any time, the latest array found (whether by daffna_c or daffpa_c)
   is regarded as the "current" array for the file in which the
   array was found.  The last DAF in which a search was started,
   executed, or continued by any of dafbfs_c, dafbbs_c, daffna_c, 
   daffpa_c or dafcs_c is regarded as the "current" DAF.  The summary 
   and name for the current array in the current DAF can be obtained
   separately, as shown above, by calls to DAFGS (get summary) and
   dafgn_c (get name).  The handle of the current DAF can also be
   obtained by calling dafgh_c (get handle).

   Once a search has been begun, it may be continued in either
   direction. That is, daffpa_c may be used to back up during a
   forward search, and daffna_c may be used to advance during a
   backward search.
 

Examples

 
   1) See Particulars. 
 

Restrictions

 
   None. 
 

Literature_References

 
   None. 
 

Author_and_Institution

 
   N.J. Bachman   (JPL) 
   W.L. Taber     (JPL) 
 

Version

 
   -CSPICE Version 1.0.0, 31-JUL-1999 (NJB) (WLT)

Index_Entries

 
   select a daf to continue searching 
 
Wed Apr  5 17:54:30 2017