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 ekucec_c

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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

       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 )

#### Abstract

       Update a character column entry in a specified EK record.

#### Required_Reading

       EK

#### Keywords

       EK
       FILES
       UTILITY

#### Brief_I/O

       VARIABLE  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_Output

       None.

       See -Particulars for a description of the effect of this routine.

#### Parameters

       None.

#### 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.

#### Files

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

#### Particulars

       This 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.

#### Restrictions

       None.

#### Literature_References

       None.

#### Author_and_Institution

       N.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_Entries

       replace character entry in an EK column

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

    Fri Dec 31 18:41:06 2021