Index Page dafrfr_c

A B C D E F G H I J K L M N O P Q R S T U V W X

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 dafrfr_c ( SpiceInt     handle,
                       SpiceInt     lenout,
                       SpiceInt   * nd,
                       SpiceInt   * ni,
                       SpiceChar  * ifname,
                       SpiceInt   * fward,
                       SpiceInt   * bward,
                       SpiceInt   * free    )

#### Abstract

       Read the contents of the file record of a DAF.

#### Required_Reading

       DAF

#### Keywords

       FILES

#### Brief_I/O

       Variable  I/O  Description
       --------  ---  --------------------------------------------------
       handle     I   Handle of an open DAF file.
       lenout     I   Available room in the output string `ifname'.
       nd         O   Number of double precision components in summaries.
       ni         O   Number of integer components in summaries.
       ifname     O   Internal file name.
       fward      O   Forward list pointer.
       bward      O   Backward list pointer.
       free       O   Free address pointer.

#### Detailed_Input

       handle         is the handle assigned to a DAF file opened for
                      reading.

       lenout         is the maximum number of characters that can be
                      accommodated in the output string `ifname'. This count
                      includes room for the terminating null character.
                      DAF internal file names may contain up to 60
                      characters, so lenout normally should be set to 61.

#### Detailed_Output

       nd,
       ni          are the numbers of double precision and integer
                   components, respectively, in each array summary in
                   the specified file.

       ifname      is the internal file name stored in the first
                   (or file) record of the specified file. `ifname'
                   should be declared with the length specified by
                   `lenout'.

       fward       is the forward list pointer. This points to the
                   first summary record in the file. (Records between
                   the first record and the first summary record are
                   reserved when the file is created, and are invisible
                   to DAF routines.)

                   DAF list pointers are actually Fortran record numbers,
                   and as such, start at one.

       bward       is the backward list pointer. This points
                   to the final summary record in the file.

       free        is the free address pointer. This contains the
                   first free address in the file. (That is, the
                   initial address of the next array to be added
                   to the file.)

                   `free' is a DAF address; for compatiblity with
                   SPICELIB, the range of DAF addresses starts at 1.

#### Parameters

       None.

#### Exceptions

       1) If the handle passed to this routine is not the handle of an
          open DAF file, the error will be signaled by a routine called
          by this routine.

       2) If the specified DAF file is not open for read access, the
          error will be diagnosed by a routine called by this routine.

       3) If the specified record cannot (for some reason) be read,
          the error SPICE(DAFFRNOTFOUND) is signaled.

#### Files

       The input `handle' should refer to a DAF file open for read
       or write access.

#### Particulars

       The file record of a DAF is the only record that contains
       any global information about the file. This record is created
       when the file is created, and is updated only when new arrays
       are added.

       Like character records, file records are not buffered.

#### Examples

       In the following example, the file record of a DAF is read
       to determine the first free address in the file.

          #include <stdio.h>
          #include "SpiceUsr.h"

          int main ()
             {
             #define IFNLEN   61

             SpiceChar               ifname[IFNLEN];

             SpiceInt                bward;
             SpiceInt                free;
             SpiceInt                fward;
             SpiceInt                handle;
             SpiceInt                nd;
             SpiceInt                ni;
             SpiceChar             * kernel = "/kernels/gen/spk/de421.bsp";

             dafopr_c ( kernel, &handle );

             dafrfr_c ( handle, IFNLEN, &nd, &ni, ifname, &fward, &bward, &free );

             printf ( "First free DAF address is %d.\n", (int)free );

            /.
             Safely close the DAF.
             ./
             dafcls_c ( handle  );

             return ( 0 );
             }

       The program outputs:

          First free DAF address is 2098645.

#### Restrictions

       None.

#### Literature_References

       None.

#### Author_and_Institution

       N.J. Bachman    (JPL)
       K.R. Gehringer  (JPL)
       I.M. Underwood  (JPL)

#### Version

       -CSPICE Version 1.0.1, 28-JUN-2016 (EDW)

          Edit to Example code, SpiceInts output as ints using
          explicit casting.

       -CSPICE Version 1.0.0, 17-JUN-2009 (NJB) (KRG) (IMU)

#### Index_Entries

       read daf file record

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

    Wed Apr  5 17:54:31 2017