| ekcls_c |
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Table of contents
Procedureekcls_c ( EK, close file ) void ekcls_c ( SpiceInt handle ) AbstractClose an E-kernel. Required_ReadingEK KeywordsEK FILES UTILITY Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- handle I EK file handle. Detailed_Input
handle is the file handle of an EK to be closed. Note
that EKs open for writing must be closed by this
routine in order to be valid.
Detailed_OutputNone. ParametersNone. Exceptions
1) If the indicated file is not recognized, no error is
signaled.
2) If an I/O error occurs while reading or writing the indicated
file, the error is signaled by a routine in the call tree of
this routine.
FilesSee the EK Required Reading for a discussion of the EK file format. ParticularsThis routine should be used to close open EK files. EK files open for writing *must* be closed by this routine in order to be valid. EK files open for read access should also be closed using this routine. 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) The following program demonstrates how to create a new EK and
add data to a character column in a given record within the
file, how to update the data in this record, and how to read
the data from it.
The example shows the effect of the ekcls_c calls when the EK
file has been opened for write or read access.
Example code begins here.
/.
Program ekcls_ex1
./
#include <stdio.h>
#include <string.h>
#include "SpiceUsr.h"
int main( )
{
/.
Local constants.
./
#define EKNAME "ekcls_ex1.bdb"
#define IFNAME "Test EK"
#define TABLE "CHR_DATA"
#define CVLEN 10
#define DECLEN 201
#define MAXVAL 4
#define NCOLS 2
#define NROWS 6
#define NRESVC 0
/.
Local variables
./
SpiceChar cdecls [NCOLS] [DECLEN];
SpiceChar cnames [NCOLS] [SPICE_EK_CSTRLN];
SpiceChar cvals [MAXVAL][CVLEN];
SpiceInt handle;
SpiceInt i;
SpiceInt nvals;
SpiceInt recno;
SpiceInt segno;
SpiceBoolean isnull;
/.
Open a new EK file. For simplicity, we won't
reserve space for the comment area, so the
number of reserved comment characters is zero.
The constant IFNAME is the internal file name.
./
ekopn_c ( EKNAME, IFNAME, NRESVC, &handle );
/.
Set up the table and column names and declarations
for the CHR_DATA segment. We'll index all of
the columns.
./
strcpy( cnames[0], "CHR_COL_1" );
strcpy( cdecls[0], "DATATYPE = CHARACTER*(*), "
"INDEXED = TRUE, NULLS_OK = TRUE" );
strcpy( cnames[1], "CHR_COL_2" );
strcpy( cdecls[1], "DATATYPE = CHARACTER*(9), "
"SIZE = VARIABLE, NULLS_OK = TRUE" );
/.
Start the segment.
./
ekbseg_c ( handle, TABLE, NCOLS, SPICE_EK_CSTRLN,
cnames, DECLEN, cdecls, &segno );
for ( i = 0; i < NROWS; i++ )
{
ekappr_c ( handle, segno, &recno );
isnull = ( i == 1 );
sprintf ( cvals[0], "%d", i );
ekacec_c ( handle, segno, recno, cnames[0],
1, CVLEN, cvals, isnull );
/.
Array-valued columns follow.
./
sprintf ( cvals[0], "%d", 10*i );
sprintf ( cvals[1], "%d", 10*i + 1 );
sprintf ( cvals[2], "%d", 10*i + 2 );
sprintf ( cvals[3], "%d", 10*i + 3 );
ekacec_c ( handle, segno, recno, cnames[1],
4, CVLEN, cvals, isnull );
}
/.
End the file.
./
ekcls_c ( handle );
/.
Open the EK for write access.
./
ekopw_c ( EKNAME, &handle );
/.
Negate the values in the odd-numbered records
using the update routines.
./
for ( i = 1; i < NROWS; i = i+2 )
{
recno = i;
isnull = ( i == 1 );
sprintf ( cvals[0], "%d", -i );
ekucec_c ( handle, segno, recno, cnames[0],
1, CVLEN, cvals, isnull );
/.
Array-valued columns follow.
./
sprintf ( cvals[0], "%d", -10*i );
sprintf ( cvals[1], "%d", -(10*i + 1) );
sprintf ( cvals[2], "%d", -(10*i + 2) );
sprintf ( cvals[3], "%d", -(10*i + 3) );
ekucec_c ( handle, segno, recno, cnames[1],
4, CVLEN, cvals, isnull );
}
/.
Close the file.
./
ekcls_c ( handle );
/.
Open the created file. Show the values added.
./
ekopr_c ( EKNAME, &handle );
for ( i = 0; i < NROWS; i++ )
{
ekrcec_c ( handle, segno, i, cnames[0],
CVLEN, &nvals, cvals, &isnull );
if ( ! isnull )
{
printf( "Data from column: %s\n", cnames[0] );
printf( " record number: %d\n", i );
printf( " values : %s\n", cvals[0] );
printf( " \n" );
}
else
{
printf( "Record %d flag is NULL.\n", i );
printf( " \n" );
}
/.
Array-valued columns follow.
./
ekrcec_c ( handle, segno, i, cnames[1],
CVLEN, &nvals, cvals, &isnull );
if ( ! isnull )
{
printf( "Data from column: %s\n", cnames[1] );
printf( " record number: %d\n", i );
printf( " values : %s %s %s %s\n",
cvals[0], cvals[1], cvals[2], cvals[3] );
printf( " \n" );
}
}
/.
Close the file.
./
ekcls_c ( handle );
return ( 0 );
}
When this program was executed on a Mac/Intel/cc/64-bit
platform, the output was:
Data from column: CHR_COL_1
record number: 0
values : 0
Data from column: CHR_COL_2
record number: 0
values : 0 1 2 3
Record 1 flag is NULL.
Data from column: CHR_COL_1
record number: 2
values : 2
Data from column: CHR_COL_2
record number: 2
values : 20 21 22 23
Data from column: CHR_COL_1
record number: 3
values : -3
Data from column: CHR_COL_2
record number: 3
values : -30 -31 -32 -33
Data from column: CHR_COL_1
record number: 4
values : 4
Data from column: CHR_COL_2
record number: 4
values : 40 41 42 43
Data from column: CHR_COL_1
record number: 5
values : -5
Data from column: CHR_COL_2
record number: 5
values : -50 -51 -52 -53
Note that the second record does not appear due to setting the
`isnull' flag to true for that record. The odd value record
numbers have negative values as a result of the update calls.
After run completion, a new EK exists in the output directory.
RestrictionsNone. Literature_ReferencesNone. Author_and_InstitutionN.J. Bachman (JPL) J. Diaz del Rio (ODC Space) Version
-CSPICE Version 1.1.1, 06-JUL-2021 (JDR)
Edited the header to comply with NAIF standard. Added complete
code example and removed non-applicable restriction.
-CSPICE Version 1.1.0, 23-JUL-2001 (NJB)
Removed tab characters from source file.
-CSPICE Version 1.0.0, 31-MAR-1998 (NJB)
Based on SPICELIB Version 1.0.0, 26-SEP-1995 (NJB)
Index_Entriesclose EK |
Fri Dec 31 18:41:05 2021