| ekucec_c |
|
Table of contents
Procedure
ekucec_c ( EK, update character column entry )
void ekucec_c ( SpiceInt handle,
SpiceInt segno,
SpiceInt recno,
ConstSpiceChar * column,
SpiceInt nvals,
SpiceInt cvalen,
const void * cvals,
SpiceBoolean isnull )
AbstractUpdate a character column entry in a specified EK record. Required_ReadingEK KeywordsEK FILES UTILITY Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- handle I EK file handle. segno I Index of segment containing record. recno I Record to which data is to be updated. column I Column name. nvals I Number of values in new column entry. cvalen I Declared length of character values. cvals I Character values comprising new column entry. isnull I Flag indicating whether column entry is null. Detailed_Input
handle is the handle of an EK file open for write access.
segno is the index of the segment containing the column entry
to be updated. EK segment numbers range from
0 to N-1, where N is the number of segments
in the kernel.
recno is the index of the record containing the column entry
to be updated. This record number is relative to the start
of the segment indicated by segno; the first
record in the segment has index 0.
column is the name of the column containing the entry to
be updated.
nvals is the number of elements in the new value to be inserted
into the specified column.
cvalen is the length of the strings in the `cvals' array, where
the length includes space for null terminators.
If the column has fixed-size entries, then `nvals'
must equal the entry size for the specified column.
cvals is the set of replacement values themselves. The values
are written into the specified column and record.
The array `cvals' should be declared with dimensions
[nelts][cvalen]
where `nelts' is greater than or equal to `nvals'.
isnull is a logical flag indicating whether the entry is
null. If `isnull' is SPICEFALSE, the column entry
defined by `nvals' and `cvals' is added to the
specified kernel file.
If `isnull' is SPICETRUE, `nvals' and `cvals' are
ignored: no data are written into the specified column
entry. The column entry is marked as a null value.
If the column has fixed-length, variable-size
entries, the number of entries is considered to
be 1.
Detailed_OutputNone. See -Particulars for a description of the effect of this routine. ParametersNone. Exceptions
1) If `handle' is invalid, an error is signaled by a routine in the
call tree of this routine.
2) If `segno' is out of range, an error is signaled by a routine in
the call tree of this routine.
3) If `column' is not the name of a declared column, an error
is signaled by a routine in the call tree of this routine.
4) If `column' specifies a column of whose data type is not
CHARACTER, the error SPICE(WRONGDATATYPE) is signaled by a
routine in the call tree of this routine.
5) If `recno' is out of range, an error is signaled by a routine in
the call tree of this routine.
6) If the specified column has fixed-size entries and `nvals' does
not match this size, an error is signaled by a routine in the
call tree of this routine.
7) If the specified column has variable-size entries and `nvals' is
non-positive, an error is signaled by a routine in the call
tree of this routine.
8) If an attempt is made to add a null value to a column that
doesn't take null values, an error is signaled by a routine in
the call tree of this routine.
9) If `column' specifies a column of whose class is not a character
class known to this routine, the error SPICE(NOCLASS) is
signaled by a routine in the call tree of this routine.
10) 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.
11) If the `column' input string pointer is null, the error
SPICE(NULLPOINTER) is signaled.
12) If the `column' input string has zero length, the error
SPICE(EMPTYSTRING) is signaled.
13) If the `cvals' input array pointer is null, the error
SPICE(NULLPOINTER) is signaled.
14) If the `cvals' input array strings have length less than two
characters, the error SPICE(STRINGTOOSHORT) is signaled.
15) If memory cannot be allocated to create the temporary variable
required for the execution of the underlying Fortran routine,
the error SPICE(MALLOCFAILED) is signaled.
FilesSee the EK Required Reading for a discussion of the EK file format. ParticularsThis routine operates by side effects: it modifies the named EK file by replacing a specified character column entry. 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.
Example code begins here.
/.
Program ekucec_ex1
./
#include <stdio.h>
#include <string.h>
#include "SpiceUsr.h"
int main( )
{
/.
Local constants.
./
#define EKNAME "ekucec_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" );
}
}
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 1.1.0, 10-AUG-2021 (JDR)
Changed input argument name "vallen" to "cvalen" for consistency
with other routines.
Edited the header to comply with NAIF standard. Added complete
code example.
-CSPICE Version 1.0.0, 28-AUG-2001 (NJB)
Index_Entriesreplace character entry in an EK column |
Fri Dec 31 18:41:06 2021