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 dafgn_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

       dafgn_c ( DAF, get array name )

       void dafgn_c ( SpiceInt     namlen,
                      SpiceChar  * name   )

#### Abstract

       Return (get) the name for the current array in the current DAF.

#### Required_Reading

       DAF

#### Keywords

       FILES

#### Brief_I/O

       VARIABLE  I/O  DESCRIPTION
       --------  ---  --------------------------------------------------
       namlen     I   Length of array name string.
       name       O   Name of current array.

#### Detailed_Input

       namlen      is the length of the `name' string, including room for the null
                   terminator. For a DAF with summary parameters ND and NI, the
                   maximum length of an array name is

                                         (NI + 1)
                      NC  =   8 * ( ND + -------- ) (Note that this is
                                             2       integer division.)

                   Given NC, `namlen' should be set equal to NC+1.

#### Detailed_Output

       name        is the name for the current array (the array found by the
                   latest call to daffna_c or daffpa_c).

#### Parameters

       None.

#### Exceptions

       1)  If this routine is called when no search is in progress in the
           current DAF, the error SPICE(DAFNOSEARCH) is signaled by a
           routine in the call tree of this routine.

       2)  If the DAF for which the "current" array's name is to be
           returned has actually been closed, an error is signaled by a
           routine in the call tree of this routine.

       3)  If no array is current in the current DAF, the error
           SPICE(NOCURRENTARRAY) is signaled by a routine in the call
           tree of this routine. There is no current array when a search
           is started by dafbfs_c or dafbbs_c, but no calls to daffna_c or
           daffpa_c have been made yet, or whenever daffna_c or daffpa_c return
           the value SPICEFALSE in the `found' argument.

       4)  If the `name' output string pointer is null, the error
           SPICE(NULLPOINTER) is signaled.

       5)  If the `name' output string has length less than two
           characters, the error SPICE(STRINGTOOSHORT) is signaled, since
           the output string is too short to contain one character of
           output data plus a null terminator.

#### Files

       None.

#### Particulars

       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_c (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)
       J. Diaz del Rio     (ODC Space)
       W.L. Taber          (JPL)
       I.M. Underwood      (JPL)

#### Version

       -CSPICE Version 1.1.0, 25-AUG-2021 (JDR)

           Changed the input argument name "lenout" to "namlen" for consistency
           with other routines.

           Edited the header to comply with NAIF standard. Moved DAF required
           reading from -Literature_References to -Required_Reading section.

           Fixed typo in -Exceptions entry #3: daffpa_c is used to find the
           previous array, not the non existing API dafbna_c.

       -CSPICE Version 1.0.0, 01-AUG-1999 (NJB) (WLT) (IMU)

#### Index_Entries

       get DAF array name

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

    Fri Dec 31 18:41:03 2021