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 ekopr_c

Table of contents

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

       ekopr_c ( EK, open file for reading )

       void ekopr_c ( ConstSpiceChar  * fname,
                      SpiceInt        * handle )

#### Abstract

       Open an existing E-kernel file for reading.

#### Required_Reading

       EK

#### Keywords

       EK
       FILES
       UTILITY

#### Brief_I/O

       VARIABLE  I/O  DESCRIPTION
       --------  ---  --------------------------------------------------
       fname      I   Name of EK file.
       handle     O   Handle attached to EK file.

#### Detailed_Input

       fname       is the name of an existing E-kernel file to be
                   opened for read access.

#### Detailed_Output

       handle      is the EK file handle of the file designated by
                   `fname'. This handle is used to identify the file
                   to other EK routines.

#### Parameters

       SPICE_DAS_FTSIZE

                   is the maximum number of DAS files that a user can
                   have open simultaneously. This includes any files used
                   by the DAS system.

                   See the header file SpiceDAS.h for the actual value of
                   this parameter.

#### Exceptions

       1)  If the indicated file cannot be opened, an error is signaled
           by a routine in the call tree of this routine.

       2)  If the indicated file has the wrong architecture version, an
           error is signaled by a routine in the call tree of this
           routine.

       3)  If an I/O error occurs while reading the indicated file, the
           error is signaled by a routine in the call tree of this
           routine.

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

       5)  If the `fname' input string has zero length, the error
           SPICE(EMPTYSTRING) is signaled.

#### Files

       See the EK Required Reading for a discussion of the EK file
       format.

#### Particulars

       This routine should be used to open an EK file for read access.
       EKs opened for read access may not be modified.

       Opening an EK file with this routine makes the EK accessible to
       the CSPICE EK readers

          ekrcec_c
          ekrced_c
          ekrcei_c

       all of which expect an EK file handle as an input argument. These
       readers allow a caller to read individual EK column entries.

       To make an EK available to the EK query system, the file must be
       loaded via eklef_c, rather than by this routine. See the EK
       Required Reading for further information.

#### Examples

       The numerical results shown for this example may differ across
       platforms. The results depend on the SPICE kernels used as
       input, the compiler and supporting libraries, and the machine
       specific arithmetic implementation.

       1) Open an EK for read access and find the number of segments in
          it.

          Use the EK kernel below as test input file for loading the
          experiment database. This kernel contains the Deep
          Impact spacecraft sequence data based on the integrated
          Predicted Events File covering the whole primary mission,
          split into two segments.

             dif_seq_050112_050729.bes

          Example code begins here.

          /.
             Program ekopr_ex1
          ./
          #include <stdio.h>
          #include "SpiceUsr.h"

          int main( )
          {

             /.
             Local variables.
             ./
             SpiceInt             handle;
             SpiceInt             nseg;

             /.
             Open the EK file, returning the file handle
             associated with the open file to the variable named
             `handle'.
             ./
             ekopr_c ( "dif_seq_050112_050729.bes", &handle );

             /.
             Return the number of segments in the EK.
             ./
             nseg = eknseg_c ( handle );
             printf( "Number of segments = %2d\n", nseg );

             /.
             Close the file.
             ./
             ekcls_c ( handle );

             return ( 0 );
          }

          When this program was executed on a Mac/Intel/cc/64-bit
          platform, the output was:

          Number of segments =  2

#### Restrictions

       1)  No more than SPICE_DAS_FTSIZE DAS files may be opened simultaneously.
           See the header file SpiceDAS.h for the value of SPICE_DAS_FTSIZE.

#### Literature_References

       None.

#### Author_and_Institution

       N.J. Bachman        (JPL)
       J. Diaz del Rio     (ODC Space)

#### Version

       -CSPICE Version 1.1.1, 10-AUG-2021 (NJB) (JDR)

           Edited the header to comply with NAIF standard. Added complete
           code example.

           Updated the -Exceptions section to correct exception #1 (this
           routine does not delete the input file if the file cannot be opened);
           and add exceptions #4 and #5.

           Added SPICE_DAS_FTSIZE parameter description.

       -CSPICE Version 1.1.0, 23-JUL-2001 (NJB)

           Removed tab characters from source file.

       -CSPICE Version 1.0.0, 27-MAR-1998 (NJB)

#### Index_Entries

       open EK for reading

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

    Fri Dec 31 18:41:06 2021