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 ekrcei_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

       ekrcei_c ( EK, read column entry element, integer )

       void ekrcei_c ( SpiceInt           handle,
                       SpiceInt           segno,
                       SpiceInt           recno,
                       ConstSpiceChar   * column,
                       SpiceInt         * nvals,
                       SpiceInt         * ivals,
                       SpiceBoolean     * isnull )

#### Abstract

       Read data from an integer column in a specified EK record.

#### Required_Reading

       EK

#### Keywords

       EK
       FILES
       UTILITY

#### Brief_I/O

       VARIABLE  I/O  DESCRIPTION
       --------  ---  --------------------------------------------------
       handle     I   Handle attached to EK file.
       segno      I   Index of segment containing record.
       recno      I   Record from which data is to be read.
       column     I   Column name.
       nvals      O   Number of values in column entry.
       ivals      O   Integer values in column entry.
       isnull     O   Flag indicating whether column entry is null.

#### Detailed_Input

       handle      is an EK file handle. The file may be open for
                   read or write access.

       segno       is the index of the segment from which data is to
                   be read. The first segment in the file has index 0.

       recno       is the index of the record from which data is to be
                   read. 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 from which data is to be
                   read.

#### Detailed_Output

       nvals,
       ivals       are, respectively, the number of values found in
                   the specified column entry and the set of values
                   themselves.

                   For columns having fixed-size entries, when a
                   a column entry is null, nvals is still set to the
                   column entry size. For columns having variable-
                   size entries, nvals is set to 1 for null entries.

       isnull      is a logical flag indicating whether the returned
                   column entry is null.

#### 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 `recno' is out of range, an error is signaled by a routine in
           the call tree of this routine.

       4)  If `column' is not the name of a declared column, an error
           is signaled by a routine in the call tree of this routine.

       5)  If `column' specifies a column of whose data type is not
           integer, the error SPICE(WRONGDATATYPE) is signaled by a
           routine in the call tree of this routine.

       6)  If `column' specifies a column of whose class is not an integer
           class known to this routine, the error SPICE(NOCLASS) is
           signaled by a routine in the call tree of this routine.

       7)  If an attempt is made to read an uninitialized column entry,
           an error is signaled by a routine in the call tree of this
           routine. A null entry is considered to be initialized, but
           entries do not contain null values by default.

       8)  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.

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

       10) If the `column' 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 is a utility that allows an EK file to be read
       directly without using the high-level query interface.

#### Examples

       1)  Read the value in the third record of the column ICOL in
           the fifth segment of an EK file designated by handle.

              #include "SpiceUsr.h"
                 .
                 .
                 .
              ekrcei_c ( handle, 4, 2, "ICOL", &n, &ival, &isnull );

#### Restrictions

       1)  EK files open for write access are not necessarily readable.
           In particular, a column entry can be read only if it has been
           initialized. The caller is responsible for determining
           when it is safe to read from files open for write access.

#### Literature_References

       None.

#### Author_and_Institution

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

#### Version

       -CSPICE Version 1.1.0, 02-AUG-2021 (JDR)

           Added "CHKFSTR" check for non-null, non-empty "column" argument.

           Edited the header to comply with NAIF standard.

       -CSPICE Version 1.0.0, 04-JUL-2000 (NJB)

#### Index_Entries

       read integer data from EK column

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

    Fri Dec 31 18:41:06 2021