The following subsections contain topics, beyond those directly
related to the RPC API, that application programmers need to know.
IDL-to-C Mappings
The Interface Definition Language (IDL) compiler converts an
interface definition into output files. The rpc_intro reference
page in the OSF DCE Command Reference contains a summary of the
idl command, which invokes the IDL compiler.
Additional information about the IDL compiler appears in the
following table, which shows the IDL base types and the IDL-to-C
mappings. The following table lists the IDL base data type
specifiers. Where applicable, the table shows the size of the
corresponding transmittable type and the type macro emitted by
the IDL compiler for resulting declarations.
Base Data Type Specifiers - rpc_intro
___________________________________________________________
Specifier Type Macro
(sign) (size) (type) Size Emitted by idl
___________________________________________________________
small int 8 bits idl_small_int
short int 16 bits idl_short_int
long int 32 bits idl_long_int
hyper int 64 bits idl_hyper_int
unsigned small int 8 bits idl_usmall_int
unsigned short int 16 bits idl_ushort_int
unsigned long int 32 bits idl_ulong_int
unsigned hyper int 64 bits idl_uhyper_int
float 32 bits idl_short_float
double 64 bits idl_long_float
char 8 bits idl_char
boolean 8 bits idl_boolean
byte 8 bits idl_byte
void - idl_void_p_t
handle_t - -
Note that you can use the idl_ macros in the code you write for an
application to ensure that your type declarations are consistent
with those in the stubs, even when the application is ported to
another platform. The idl_ macros are especially useful when
passing constant values to RPC calls. For maximum portability,
all constants passed to RPC calls declared in your network
interfaces should be cast to the appropriate type because the size
of integer constants (like the size of the int data type) is
unspecified in the C language. The idl_ macros are defined in
SYS$COMMON:[DCE$LIBRARY]IDLBASE.H, which is included by header
files that the IDL compiler generates.
Management Commands for Programmers
In addition to the idl command for programmers, DCE RPC provides
two management commands for the RPC control program and the DCE
Host daemon, as follows:
+ The rpccp control program accesses RPCCP, the RPC control
program. This program provides a set of commands for
accessing the operations of the RPC Name Service Interface
(NSI operations). RPCCP also supports showing the elements
of the local endpoint map and removing elements from it.
You can manage the name service with RPCCP commands or with DCE
RPC runtime routines. For example, suppose you want to obtain
the members of a group. You can give the show group command to
RPCCP or you can write an application program that calls the
following DCE RPC runtime routines:
- rpc_ns_group_mbr_inq_begin()
- rpc_ns_group_mbr_inq_next()
- rpc_ns_group_mbr_inq_done()
+ The dced command starts the DCE Host daemon. The daemon
maintains the local endpoint map for RPC servers and looks
up endpoints for RPC clients.
See the OSF DCE Administration Reference for more information about
these two management commands.