RPCGEN(1) BSD General Commands Manual RPCGEN(1)NAMErpcgen — an RPC protocol compiler
rpcgen [-a] [-b] [-C] [-Dname[=value]] [-i size] [-I -P [-K seconds]]
[-L] [-M] [-N] [-T] [-Y pathname] infile
rpcgen [-c | -h | -l | -m | -t | -Sc | -Ss | -Sm] [-o outfile] [infile]
rpcgen [-s nettype] [-o outfile] [infile]
rpcgen [-n netid] [-o outfile] [infile]
The rpcgen utility 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).
The rpcgen utility is normally used as in the first synopsis where it
takes an input file and generates three output files. If the infile is
named proto.x, then rpcgen generates a header 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 also generates the RPC dispatch ta‐
ble in proto_tbl.i.
The rpcgen utility can also generate sample client and server files that
can be customized to suit a particular application. The -Sc, -Ss and -Sm
options generate sample client, server and makefile, respectively. The
-a option generates all files, including sample files. If the infile is
proto.x, then the client side sample file is written to proto_client.c,
the server side sample file to proto_server.c and the sample makefile to
If option -I is set, the server created can be started both by the port
monitors (for example, inetd(8)) 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 may be specified
by setting up the environment variable NLSPROVIDER. When the server gen‐
erated 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 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 cre‐
ation 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 proce‐
· 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. See the
EXAMPLES section below for examples of rpcgen usage. When rpcgen is exe‐
cuted 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 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:
defined when compiling into headers
defined when compiling into XDR routines
defined when compiling into server-side stubs
defined when compiling into client-side stubs
defined when compiling into RPC dispatch tables
Any line beginning with “%” is passed directly into the output file,
uninterpreted by rpcgen. To specify the path name of the C preprocessor
use -Y flag.
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
The following options are available:
-a Generate all files, including sample files.
-b Backward compatibility mode. Generate transport specific RPC
code for older versions of the operating system.
-c Compile into XDR routines.
-C Generate ANSI C code. This is always done, the flag is only pro‐
vided for backwards compatibility.
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). -T option can be
used in conjunction to produce a header which supports RPC dis‐
Size at which to start generating inline code. This option is
useful for optimization. The default size is 5.
Note: in order to provide backwards compatibility with the older
rpcgen on the FreeBSD platform, the default is actually 0 (which
means that inline code generation is disabled by default). You
must specify a non-zero value explicitly to override this
-I Compile support for inetd(8) in the server side stubs. Such
servers can be self-started or can be started by inetd(8). When
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, or the user may simply compile without the
If there are no pending client requests, the inetd(8) servers
exit after 120 seconds (default). The default can be changed
with the -K option. All the error messages for inetd(8) servers
are always logged with syslog(3).
Note: Contrary to some systems, in FreeBSD this option is needed
to generate servers that can be invoked through portmonitors and
By default, services created using rpcgen and invoked through
port monitors 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,
use -K 0. To create a server that never exits, the appropriate
argument is -K -1.
When monitoring for a server, some portmonitors 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 0.
-l Compile into client-side stubs.
-L When the servers are started in foreground, use syslog(3) to log
the server errors instead of printing them on the standard error.
-m Compile into server-side stubs, but do not generate a "main" rou‐
tine. This option is useful for doing callback-routines and for
users who need to write their own "main" routine to do initial‐
-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. How‐
ever, the rpc_svc_calls(3) functions are not yet MT-safe, which
means that rpcgen generated server-side code will not be MT-safe.
-N Allow 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 can pass the argument itself.
This behavior is different from the old style of rpcgen generated
code. To maintain backward compatibility, this option is not the
Compile into server-side stubs for the transport specified by
netid. There should be an entry for netid in the netconfig data‐
base. This option may be specified more than once, so as to com‐
pile a server that serves multiple transports.
Specify the name of the output file. If none is specified, stan‐
dard output is used (-c, -h, -l, -m, -n, -s, -Sc, -Sm, -Ss, and
-t modes only).
-P Compile support for port monitors in the server side stubs.
Note: Contrary to some systems, in FreeBSD this option is needed
to generate servers that can be monitored.
If the -I option has been specified, -P is turned off automati‐
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(3) for the meanings associated with these classes).
This option may be specified more than once. Note: the trans‐
ports are chosen at run time and not at compile time.
-Sc Generate sample client code that uses remote procedure calls.
-Sm Generate a sample Makefile which can be used for compiling the
-Ss Generate sample server code that uses remote procedure calls.
-t Compile into RPC dispatch table.
-T Generate the code to support RPC dispatch tables.
The options -c, -h, -l, -m, -s, -Sc, -Sm, -Ss, 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
Give the name of the directory where rpcgen will start looking
for the C-preprocessor.
The following example:
example% rpcgen-T prot.x
generates all the five files: prot.h, prot_clnt.c, prot_svc.c, prot_xdr.c
The following example sends the C data-definitions (header) to the stan‐
example% 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:
example% rpcgen-s datagram_n -DTEST prot.x
To create the server side stubs for the transport indicated by netid tcp,
example% rpcgen-n tcp -o prot_svc.c prot.x
SEE ALSOcc(1), rpc(3), rpc_svc_calls(3), syslog(3), xdr(3), inetd(8)
The rpcgen chapter in the NETP manual.
BSD September 2, 2005 BSD