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Required Reading


   CSPICE_DAFEC reads comment text from the comment area of a DAF.



      handle   file handle referring to a DAF file.

               [1,1] = size(handle); int32 = class(handle)

      bufsiz   the maximum number of comment lines to copy to 'buffer'.

               [1,1] = size(bufsiz); int32 = class(bufsiz)

      lenout   allowed length of each string element of the output 'buffer'.
               This length must be large enough to hold the longest output
               string. The SPICE system imposes no limit on the length of
               comment lines, so 'lenout' normally should be set to a
               "generous" value that is unlikely to be exceeded.

               [1,1] = size(lenout); int32 = class(lenout)

   the call:

      [buffer, done] = cspice_dafec( handle, bufsiz, lenout )


      buffer   array containing the comment lines read from the DAF
               associated with 'handle'.

               On output, 'buffer' contains 'bufsiz' or less strings of comment
               text, with one comment line per string ( bufsiz >= n).

               [n,c1] = size(buffer); char = class(buffer)

      done     logical indicating whether or not all of the comment
               lines from the comment area of the DAF have been read. This
               variable has value true after the last comment line has been
               read. It will have a false value otherwise.

               If no comments exist in the comment area, this variable
               returns as true.

               [1,1] = size(done); logical = class(done)


   Any numerical results shown for this example may differ between
   platforms as the results depend on the SPICE kernels used as input
   and the machine specific arithmetic implementation.

      % Define an SPK from which to extract the comment area.
      SPK        = 'de421.bsp';

      % Define the size of the comment area to read from the SPK.
      % 15 lines, each with length 80 characters.
      BUFSIZE    = 15;
      LINLEN     = 80;

      % Open the 'SPK' for reading, return the corresponding
      % file handle to 'handle'.
      handle = cspice_dafopr( SPK );

      done = false;

      [buf, done] = cspice_dafec( handle, BUFSIZE, LINLEN );
      output = cellstr(buf);

      for i=1:numel(output)
         fprintf( '%s\n', char(output(i)) );

      if done
         fprintf( 'All comments read from file.\n' );
         fprintf( 'Not all comments read from file.\n' );

      % SAFELY close the file.
      cspice_dafcls( handle )

   Matlab outputs:

      ; de421.bsp LOG FILE
      ; Created 2008-02-12/11:33:34.00.

      LEAPSECONDS_FILE    = naif0007.tls
      SPK_FILE            = de421.bsp
        SPK_LOG_FILE      = de421_spk_conversion.log
        NOTE              = NIOSPK 6.1.0 Conversion
        SOURCE_NIO_FILE   = de421.nio
          BEGIN_TIME      = CAL-ET 1899 JUL 29 00:00:00.000
          END_TIME        = CAL-ET 2053 OCT 09 00:00:00.000


      Not all comments read from file.

   The program outputs BUFSIZ (15) lines from the 'SPK' comment area.
   Additional calls to cspice_dafec will read more comment lines
   from the SPK in slices of BUFSIZ.

   Reading all comment lines from 'SPK' requires a large value for BUFSIZ.
   In this case, a BUFSIZ value of 50 will read all comment lines from
   'SPK' in a single cspice_dafec.


   A binary DAF contains an area which is reserved for storing
   annotations or descriptive textual information describing the data
   contained in a file. This area is referred to as the ``comment
   area'' of the file. The comment area of a DAF is a line
   oriented medium for storing textual information. The comment
   area preserves any leading or embedded white space in the line(s)
   of text which are stored, so that the appearance of the of
   information will be unchanged when it is retrieved (extracted) at
   some other time. Trailing blanks, however, are NOT preserved,
   due to the way that character strings are represented in
   standard Fortran 77.

   This routine will read the comments from the comment area of
   a binary DAF, placing them into a line buffer. If the line
   buffer is not large enough to hold the entire comment area,
   the portion read will be returned to the caller, and the DONE
   flag will be set to false. This allows the comment area to be
   read in ``chunks,'' a buffer at a time. After all of the comment
   lines have been read, the `done' flag will be set to true.

   This routine can be used to ``simultaneously'' extract comments
   from the comment areas of multiple binary DAFs.

Required Reading

   For important details concerning this module's function, please refer to
   the CSPICE routine dafec_c.



   -Mice Version 1.0.0, 20-JUL-2012, EDW (JPL)


    extract comments from a DAF

Wed Apr  5 18:00:30 2017