File:      FIDO.metaker
Created:   29-JUL-2000 (NJB)


This is an example meta-kernel intended to support experimental use of the
SPICE Toolkit in the PC/VxWorks environment.  

This file adheres to the SPICE text kernel format.  The file starts out
with some (in this case long-winded) comments.  The first \begindata token 
by itself on a line indicates the start of the data area.  The data area
consists of "keyword=value" assignments.  New comment blocks are introduced by
the \begintext token alone on a line.  The file should contain no non-printing
characters and should have no lines over 80 characters in length.

Programs linked to CSPICE can load SPICE kernels by listing in this
file the file names of the kernels themselves.  The ANSI C or C++
code used to load this file could be the following:

   /*
   Include CSPICE definitions prior to any references to CSPICE code.

   The SpiceUsr.h include file referenced below uses the construct

       #ifdef __cplusplus
           extern "C" { 
       #endif
           .
           .
           .
       #ifdef __cplusplus
          }
       #endif
   
   to suppress name-mangling in C++ code.  The C code shown below compiles
   and links under g++ and should do so under other C++ compilers.  If your
   compiler does not automatically generate the -D__cplusplus flag, this
   flag would have to be added to your list of compiler options when
   building code that calls CSPICE.

   */
   #include "SpiceUsr.h"
            .
            .
            .

   /*
   Define a symbol for the meta-kernel name. The SPICE system does not
   require any particular naming convention to be followed, other than
   that the name should contain only printing, non-blank characters and
   be a valid name on the host file system.
  
   (A symbol is used to centralize the string containing the literal file
   name.)
   */
   #define METAKER "FIDO.metaker"

            .
            .
            .

   /*
   Load the meta-kernel.   
   */
   furnsh_c ( METAKER );
            .
            .
            .
       [do real work]



The code fragment shown above typically would be placed with your program's
intialization code:  the desired kernels would be loaded once, before any
attempts were made to use data from the kernels.

For details on metakernels and the related SPICE kernel pool API,see 
the KERNEL "Required Reading" as well as the "header" comments in the
source files

    furnsh_c.c
    kinfo_c.c
    kdata_c.c
    ktotal_c.c 
    uload_c.c


The kernels referenced below are sample SPK (ephemeris data), PCK (orientation
and shape models), LSK (leapseconds and constants needed for UTC-ET
conversion), and FK (frames) kernel files.  For further information, see the 
SPK, PCK, TIME, and FRAMES Required Reading.

The example below uses a "meta-kernel symbol" to reference the fully-qualified
path names of the kernel files.  This feature is not strictly necessary but
allows your program to access kernels that do not reside in your current
working directory.

All of the above lines are comments and ignored by furnsh_c.  Data
assignments follow.

Note that the string values on the right hand side of the PATH_VALUES
assignment should be replaced with the actual, full path names of 
the kernels.  

In order, the files referenced below are PCK, LSK, FK, and SPK
kernels.
 
\begindata


   PATH_VALUES      =  ( '/ftp/pub/naif/FIDO/kernels/pck',
                         '/ftp/pub/naif/FIDO/kernels/lsk',
                         '/ftp/pub/naif/FIDO/kernels/fk',
                         '/ftp/pub/naif/FIDO/kernels/spk'  )

   PATH_SYMBOLS     =  ( 'PCK', 'LSK', 'FK', 'SPK' )

   KERNELS_TO_LOAD  =  ( '$PCK/pck00007.tpc',
                         '$LSK/naif0007.tls',
                         '$FK/fido.tf',
                         '$SPK/fido.bsp'      )

\begintext

The final \begintext token above is not required.  It makes it possible 
to simply concatenate other SPICE text kernels to this one (although one 
normally wouldn't do that with a metakernel.)  It also can be useful
to see a comment indicating the end of the kernel, so users can visually
check that the kernel has not been truncated. 

(End of metakernel)