The attribute configuration file (.acf) is an optional additional input file to the IDL compiler, that, if present, affects the IDL compiler's output in various ways. The difference between the purpose of the .idl and an .acf file is that while the .idl file defines how the network communications between the client and server are handled, the .acf file, if one is present, affects only the interaction between the stub code modules and the developer code that they support. In other words, changing the contents of an .acf file has no effect on the network communications between the client and server.
Nevertheless, some of the features offered by an .acf file are very important, and they cannot be obtained by any other means. For example, The comm_status attribute configuration file attribute allows the status code of a communications failure that occurs in an RPC to be stored as a parameter or returned as a result, rather than being raised to the caller code as an exception. This attribute can only be declared in an .acf file; it cannot be declared in an .idl file. Another very important function of the .acf file is the specification of a binding method to be used by remote clients of the application. Three methods are available, as follows:
· auto_handle
· implicit_handle
· explicit_handle (the default)
These binding methods are described in Binding. The binding method you choose determines how much attention your server's clients will have to devote to the upkeep of their binding handles.
See the OSF DCE Application Development Guide - Core Components for a description of the attribute configuration file attributes available for use in attribute configuration files.