OSF DCE Application Development Guide--Core Components

RPC and Other DCE Components
14.3.1.8 Environment Variables
DCE RPC provides predefined environment variables that a client can use for NSI
operations. An environment variable is a variable that stores information, such as a
name, about a particular environment. The NSI interface provides two environment
variables, RPC_DEFAULT_ENTRY and RPC_DEFAULT_ENTRY_SYNTAX,
which are described in the OSF DCE Application Development Reference. Used
together, these environment variables identify an entry name and indicate its
syntax.
When a client searches for binding information, the search starts with a specific
entry name. Optionally, a client can specify this entry name as the value of the
RPC_DEFAULT_ENTRY variable. A client can also specify the name syntax of the
starting entry as the value of the RPC_DEFAULT_ENTRY_SYNTAX variable; the
default name syntax is dce .
Note: The dce name syntax is the only syntax currently supported by CDS.
However, NSI is independent of any specific directory service and
depending on your vendor, may support one or more alternative directory
services that use different name syntaxes.
14.3.2 Searching the Namespace for Binding Information
Searching the namespace for binding information requires that a client specify a
starting point for the search. A client can start with a specific server entry. However,
this is a limiting approach because the client is restricted to using one server. To avoid
this, a client can start searching with a group or a profile instead of with a server entry.
Searches that start with a profile or a group should encounter the server entry of a
compatible server. If such an entry is not encountered, a search operation returns the
rpc_s_no_more_bindings status code to the client. When calling the routines
rpc_ns_binding_import_next( ) or rpc_ns_binding_lookup_next( ), a client must
track whether the routine returns this status code.
14.3.2.1 The import_next and lookup_next Search Algorithm
The NSI search operations (import_next and lookup_next) traverse one or more
entries in the namespace when searching for compatible binding information. In each
directory service entry, these operations ignore non-RPC attributes and process the NSI
attributes in the following order:
1. Binding attribute (and object attribute, if present)
2. Group attribute
3. Profile attribute
If an NSI search path includes a group attribute, the search path can encompass every
entry named as a group member. If a search path includes a profile attribute, the search
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