Provided by: libc-dev-bin_2.31-0ubuntu9.17_amd64 
NAME
rpcgen - an RPC protocol compiler
SYNOPSIS
rpcgen infile
rpcgen [-Dname[=value]] [-T] [-K secs] infile
rpcgen -c|-h|-l|-m|-M|-t [-o outfile ] infile
rpcgen [-I] -s nettype [-o outfile] infile
rpcgen -n netid [-o outfile] infile
DESCRIPTION
rpcgen is a tool that generates C code to implement an RPC protocol. The input to rpcgen is a language
similar to C known as RPC Language (Remote Procedure Call Language).
rpcgen is normally used as in the first synopsis where it takes an input file and generates up to four
output files. If the infile is named proto.x, then rpcgen will generate a header file in proto.h, XDR
routines in proto_xdr.c, server-side stubs in proto_svc.c, and client-side stubs in proto_clnt.c. With
the -T option, it will also generate the RPC dispatch table in proto_tbl.i. With the -Sc option, it will
also generate sample code which would illustrate how to use the remote procedures on the client side.
This code would be created in proto_client.c. With the -Ss option, it will also generate a sample server
code which would illustrate how to write the remote procedures. This code would be created in
proto_server.c.
The server created can be started both by the port monitors (for example, inetd or listen) or by itself.
When it is started by a port monitor, it creates servers only for the transport for which the file
descriptor 0 was passed. The name of the transport must be specified by setting up the environmental
variable PM_TRANSPORT. When the server generated by rpcgen is executed, it creates server handles for
all the transports specified in NETPATH environment variable, or if it is unset, it creates server
handles for all the visible transports from /etc/netconfig file. Note: the transports are chosen at run
time and not at compile time.
When built for a port monitor (rpcgen -I), and that the server is self-started, it backgrounds itself by
default. A special define symbol RPC_SVC_FG can be used to run the server process in foreground.
The second synopsis provides special features which allow for the creation of more sophisticated RPC
servers. These features include support for user provided #defines and RPC dispatch tables. The entries
in the RPC dispatch table contain:
• pointers to the service routine corresponding to that procedure,
• a pointer to the input and output arguments
• the size of these routines
A server can use the dispatch table to check authorization and then to execute the service routine; a
client library may use it to deal with the details of storage management and XDR data conversion.
The other three synopses shown above are used when one does not want to generate all the output files,
but only a particular one. Some examples of their usage is described in the EXAMPLE section below. When
rpcgen is executed with the -s option, it creates servers for that particular class of transports. When
executed with the -n option, it creates a server for the transport specified by netid. If infile is not
specified, rpcgen accepts the standard input.
The C preprocessor, cc -E [see cc(1)], is run on the input file before it is actually interpreted by
rpcgen. For each type of output file, rpcgen defines a special preprocessor symbol for use by the rpcgen
programmer:
RPC_HDR defined when compiling into header files
RPC_XDR defined when compiling into XDR routines
RPC_SVC defined when compiling into server-side stubs
RPC_CLNT defined when compiling into client-side stubs
RPC_TBL defined when compiling into RPC dispatch tables
Any line beginning with `%' is passed directly into the output file, uninterpreted by rpcgen.
For every data type referred to in infile, rpcgen assumes that there exists a routine with the string
xdr_ prepended to the name of the data type. If this routine does not exist in the RPC/XDR library, it
must be provided. Providing an undefined data type allows customization of XDR routines.
The following options are available:
-a Generate all the files including sample code for client and server side.
-b This generates code for the SunOS4.1 style of rpc. It is for backward compatibility. This is the
default.
-5 This generates code for the SysVr4 style of rpc. It is used by the Transport Independent RPC that
is in Svr4 systems. By default rpcgen generates code for SunOS4.1 stype of rpc.
-c Compile into XDR routines.
-C Generate code in ANSI C. This option also generates code that could be compiled with the C++
compiler. This is the default.
-k Generate code in K&R C. The default is ANSI C.
-Dname[=value]
Define a symbol name. Equivalent to the #define directive in the source. If no value is given,
value is defined as 1. This option may be specified more than once.
-h Compile into C data-definitions (a header file). -T option can be used in conjunction to produce
a header file which supports RPC dispatch tables.
-I Generate a service that can be started from inetd. The default is to generate a static service
that handles transports selected with -s. Using -I allows starting a service by either method.
-K secs
By default, services created using rpcgen wait 120 seconds after servicing a request before
exiting. That interval can be changed using the -K flag. To create a server that exits
immediately upon servicing a request, -K 0 can be used. To create a server that never exits, the
appropriate argument is -K -1.
When monitoring for a server, some portmonitors, like listen(1M), always spawn a new process in
response to a service request. If it is known that a server will be used with such a monitor, the
server should exit immediately on completion. For such servers, rpcgen should be used with -K -1.
-l Compile into client-side stubs.
-m Compile into server-side stubs, but do not generate a “main” routine. This option is useful for
doing callback-routines and for users who need to write their own “main” routine to do
initialization.
-M Generate multithread-safe stubs for passing arguments and results between rpcgen-generated code
and user written code. This option is useful for users who want to use threads in their code.
-n netid
Compile into server-side stubs for the transport specified by netid. There should be an entry for
netid in the netconfig database. This option may be specified more than once, so as to compile a
server that serves multiple transports.
-N Use the newstyle of rpcgen. This allows procedures to have multiple arguments. It also uses the
style of parameter passing that closely resembles C. So, when passing an argument to a remote
procedure you do not have to pass a pointer to the argument but the argument itself. This
behaviour is different from the oldstyle of rpcgen generated code. The newstyle is not the
default case because of backward compatibility.
-o outfile
Specify the name of the output file. If none is specified, standard output is used (-c, -h, -l,
-m, -n, -s, -Sc, -Sm, -Ss, and -t modes only).
-s nettype
Compile into server-side stubs for all the transports belonging to the class nettype. The
supported classes are netpath, visible, circuit_n, circuit_v, datagram_n, datagram_v, tcp, and udp
[see rpc(3N) for the meanings associated with these classes]. This option may be specified more
than once. Note: the transports are chosen at run time and not at compile time.
-Sc Generate sample code to show the use of remote procedure and how to bind to the server before
calling the client side stubs generated by rpcgen.
-Sm Generate a sample Makefile which can be used for compiling the application.
-Ss Generate skeleton code for the remote procedures on the server side. You would need to fill in
the actual code for the remote procedures.
-t Compile into RPC dispatch table.
-T Generate the code to support RPC dispatch tables.
The options -c, -h, -l, -m, -s and -t are used exclusively to generate a particular type of file, while
the options -D and -T are global and can be used with the other options.
NOTES
The RPC Language does not support nesting of structures. As a work-around, structures can be declared at
the top-level, and their name used inside other structures in order to achieve the same effect.
Name clashes can occur when using program definitions, since the apparent scoping does not really apply.
Most of these can be avoided by giving unique names for programs, versions, procedures and types.
The server code generated with -n option refers to the transport indicated by netid and hence is very
site specific.
EXAMPLE
The following example:
$ rpcgen -T prot.x
generates the five files: prot.h, prot_clnt.c, prot_svc.c, prot_xdr.c and prot_tbl.i.
The following example sends the C data-definitions (header file) to the standard output.
$ rpcgen -h prot.x
To send the test version of the -DTEST, server side stubs for all the transport belonging to the class
datagram_n to standard output, use:
$ rpcgen -s datagram_n -DTEST prot.x
To create the server side stubs for the transport indicated by netid tcp, use:
$ rpcgen -n tcp -o prot_svc.c prot.x
SEE ALSO
cc(1).
rpcgen(1)