OSF DCE Application Development Guide--Core Components

Interface Deﬁnition Language

17.8 Import Declarations

The IDL import_declaration speciﬁes interface deﬁnition ﬁles that declare types and

constants used by the importing interface. It takes the following form:

import ﬁle ,... ;

The ﬁle argument is the pathname, enclosed in double quotes, of the interface deﬁnition

you are importing. This pathname can be relative; the -I option of the IDL compiler

allows you to specify a directory from which to resolve import pathnames.

The effect of an import declaration is as if all constant, type, and import declarations

from the imported ﬁle occurred in the importing ﬁle at the point where the import

declaration occurs. Operation declarations are not imported.

For example, suppose that the interface deﬁnition aioli.idl contains a declaration to

import the deﬁnitions for the garlic and oil interfaces:

import "garlic.idl", "oil.idl";

The IDL compiler will generate a C header ﬁle named aioli.h that contains the following

#include directives:

#include "garlic.h"

#include "oil.h"

The stub ﬁles that the compiler generates will not contain code for any garlic and oil

operations.

Importing an interface many times has the same effect as importing it once.

17.9 Constant Declarations

The IDL constant_declaration can take any one of the following forms:

const integer_type_spec identiﬁer = integer | value | integer_const_expression;

const boolean identiﬁer = TRUE | FALSE | value;

const char identiﬁer = character | value;

const char* identiﬁer = string | value;

const void* identiﬁer = NULL | value;

The integer_type_spec is the data type of the integer constant you are declaring. The

identiﬁer is the name of the constant. The integer, integer_const_expression, character,

string,orvalue speciﬁes the value to be assigned to the constant. A value can be any

previously deﬁned constant.

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