get_native_type (3) - Linux Manuals

get_native_type: returns the native data type of a field in a dirfile

NAME

get_native_type --- returns the native data type of a field in a dirfile

SYNOPSIS

#include <getdata.h>
gd_type_t get_native_type(DIRFILE *dirfile, const char *field_code);

DESCRIPTION

The get_native_type() function queries a dirfile(5) database specified by dirfile and returns the native data type of the field field_code, which may contain a representation suffix.

The dirfile argument must point to a valid DIRFILE object previously created by a call to dirfile_open(3).

The native data type of a field of a given entry type is calculated as:

BIT~or~INDEX~Entry:
GD_UINT64;
CONST~Entry:
the data type of the constant;
LINCOM~or~POLYNOM~Entry:
if any of the scalar parameters is complex valued, or if the native data type of any of the input fields is complex valued: GD_COMPLEX128, otherwise: GD_FLOAT64;
LINTERP~Entry:
if the look-up table is complex valued: GD_COMPLEX128, otherwise: GD_FLOAT64;
MULTIPLY~Entry:
if either input field is complex valued: GD_COMPLEX128, otherwise: GD_FLOAT64; .TP PHASE~Entry: the native data type of the input field;
RAW~Entry:
the data type of the raw data on disk;
SBIT~Entry:
GD_INT64;
STRING~Entry:
GD_NULL.

Furthermore, if the supplied field_code contains a representation suffix, and the native data type of the field is complex valued, the native type returned will be the corresponding real valued type.

RETURN VALUE

Upon successful completion, get_native_type() returns the native data type of the field code specified. This will be one of the symbols:
GD_NULL,~GD_UINT8,~GD_INT8,~GD_UINT16,~GD_INT16,~GD_UINT32, GD_INT32,~GD_FLOAT32,~GD_FLOAT64,~GD_COMPLEX64,~GD_COMPLEX128. The meanings of these symbols are explained in the getdata(3) manual page. On error, it returns GD_UNKNOWN and sets the dirfile error to a non-zero error value. Possible error values are:
GD_E_BAD_CODE
The field specified by field_code or one of the fields it uses as input was not found in the database.
GD_E_BAD_DIRFILE
The supplied dirfile was invalid.
GD_E_BAD_REPR
The representation suffix specified in field_code, or in one of its input fields, was not recognised.
GD_E_BAD_SCALAR
A non-literal scalar used in the definition of the field or one of its inputs was not found, or was not a CONST field.
GD_E_DIMENSION
A scalar field was found where a vector field was expected.
GD_E_OPEN_LINFILE
An error occurred while trying to read a LINTERP table from disk.
GD_E_RECURSE_LEVEL
Too many levels of recursion were encountered while trying to resolve field_code. This usually indicates a circular dependency in field specification in the dirfile. The dirfile error may be retrieved by calling get_error(3). A descriptive error string for the last error encountered can be obtained from a call to get_error_string(3).