NAME

     rpc_clnt_calls, clnt_call, clnt_freeres, clnt_geterr, clnt_perrno, clnt_perror,
     clnt_sperrno, clnt_sperror, rpc_broadcast, rpc_broadcast_exp, rpc_call — library routines
     for client side calls

SYNOPSIS

     #include <rpc/rpc.h>

     enum clnt_stat
     clnt_call(CLIENT *clnt, const rpcproc_t procnum, const xdrproc_t inproc, const caddr_t in,
         const xdrproc_t outproc, caddr_t out, const struct timeval tout);

     bool_t
     clnt_freeres(CLIENT *clnt, const xdrproc_t outproc, caddr_t out);

     void
     clnt_geterr(const CLIENT * clnt, struct rpc_err * errp);

     void
     clnt_perrno(const enum clnt_stat stat);

     void
     clnt_perror(CLIENT *clnt, const char *s);

     char *
     clnt_sperrno(const enum clnt_stat stat);

     char *
     clnt_sperror(CLIENT *clnt, const char * s);

     enum clnt_stat
     rpc_broadcast(const rpcprog_t prognum, const rpcvers_t versnum, const rpcproc_t procnum,
         const xdrproc_t inproc, const caddr_t in, const xdrproc_t outproc, caddr_t out,
         const resultproc_t eachresult, const char *nettype);

     enum clnt_stat
     rpc_broadcast_exp(const rpcprog_t prognum, const rpcvers_t versnum, const rpcproc_t procnum,
         const xdrproc_t xargs, caddr_t argsp, const xdrproc_t xresults, caddr_t resultsp,
         const resultproc_t eachresult, const int inittime, const int waittime,
         const char * nettype);

     enum clnt_stat
     rpc_call(const char *host, const rpcprog_t prognum, const rpcvers_t versnum,
         const rpcproc_t procnum, const xdrproc_t inproc, const char *in,
         const xdrproc_t outproc, char *out, const char *nettype);

DESCRIPTION

     RPC library routines allow C language programs to make procedure calls on other machines
     across the network.  First, the client calls a procedure to send a request to the server.
     Upon receipt of the request, the server calls a dispatch routine to perform the requested
     service, and then sends back a reply.

     The clnt_call(), rpc_call(), and rpc_broadcast() routines handle the client side of the
     procedure call.  The remaining routines deal with error handling in the case of errors.

     Some of the routines take a CLIENT handle as one of the arguments.  A CLIENT handle can be
     created by an RPC creation routine such as clnt_create() (see rpc_clnt_create(3)).

     These routines are safe for use in multithreaded applications.  CLIENT handles can be shared
     between threads, however in this implementation requests by different threads are serialized
     (that is, the first request will receive its results before the second request is sent).

Routines

     See rpc(3) for the definition of the CLIENT data structure.

     clnt_call()
            A function macro that calls the remote procedure procnum associated with the client
            handle, clnt, which is obtained with an RPC client creation routine such as
            clnt_create() (see rpc_clnt_create(3)).  The inproc argument is the XDR function used
            to encode the procedure's arguments, and outproc is the XDR function used to decode
            the procedure's results; in is the address of the procedure's argument(s), and out is
            the address of where to place the result(s).  The tout argument is the time allowed
            for results to be returned, which is overridden by a time-out set explicitly through
            clnt_control(), see rpc_clnt_create(3).  If the remote call succeeds, the status
            returned is RPC_SUCCESS, otherwise an appropriate status is returned.

     clnt_freeres()
            A function macro that frees any data allocated by the RPC/XDR system when it decoded
            the results of an RPC call.  The out argument is the address of the results, and
            outproc is the XDR routine describing the results.  This routine returns 1 if the
            results were successfully freed, and 0 otherwise.

     clnt_geterr()
            A function macro that copies the error structure out of the client handle to the
            structure at address errp.

     clnt_perrno()
            Print a message to standard error corresponding to the condition indicated by stat.
            A newline is appended.  Normally used after a procedure call fails for a routine for
            which a client handle is not needed, for instance rpc_call().

     clnt_perror()
            Print a message to the standard error indicating why an RPC call failed; clnt is the
            handle used to do the call.  The message is prepended with string s and a colon.  A
            newline is appended.  Normally used after a remote procedure call fails for a routine
            which requires a client handle, for instance clnt_call().

     clnt_sperrno()
            Take the same arguments as clnt_perrno(), but instead of sending a message to the
            standard error indicating why an RPC call failed, return a pointer to a string which
            contains the message.  The clnt_sperrno() function is normally used instead of
            clnt_perrno() when the program does not have a standard error (as a program running
            as a server quite likely does not), or if the programmer does not want the message to
            be output with printf() (see printf(3)), or if a message format different than that
            supported by clnt_perrno() is to be used.  Note: unlike clnt_sperror() and
            clnt_spcreateerror() (see rpc_clnt_create(3)), clnt_sperrno() does not return pointer
            to static data so the result will not get overwritten on each call.

     clnt_sperror()
            Like clnt_perror(), except that (like clnt_sperrno()) it returns a string instead of
            printing to standard error.  However, clnt_sperror() does not append a newline at the
            end of the message.  Warning: returns pointer to a buffer that is overwritten on each
            call.

     rpc_broadcast()
            Like rpc_call(), except the call message is broadcast to all the connectionless
            transports specified by nettype.  If nettype is NULL, it defaults to "netpath".  Each
            time it receives a response, this routine calls eachresult(), whose form is: bool_t
            eachresult(caddr_t out, const struct netbuf * addr, const struct netconfig * netconf)
            where out is the same as out passed to rpc_broadcast(), except that the remote
            procedure's output is decoded there; addr points to the address of the machine that
            sent the results, and netconf is the netconfig structure of the transport on which
            the remote server responded.  If eachresult() returns 0, rpc_broadcast() waits for
            more replies; otherwise it returns with appropriate status.  Warning: broadcast file
            descriptors are limited in size to the maximum transfer size of that transport.  For
            Ethernet, this value is 1500 bytes.  The rpc_broadcast() function uses AUTH_SYS
            credentials by default (see rpc_clnt_auth(3)).

     rpc_broadcast_exp()
            Like rpc_broadcast(), except that the initial timeout, inittime and the maximum
            timeout, waittime are specified in milliseconds.  The inittime argument is the
            initial time that rpc_broadcast_exp() waits before resending the request.  After the
            first resend, the re-transmission interval increases exponentially until it exceeds
            waittime.

     rpc_call()
            Call the remote procedure associated with prognum, versnum, and procnum on the
            machine, host.  The inproc argument is used to encode the procedure's arguments, and
            outproc is used to decode the procedure's results; in is the address of the
            procedure's argument(s), and out is the address of where to place the result(s).  The
            nettype argument can be any of the values listed on rpc(3).  This routine returns
            RPC_SUCCESS if it succeeds, or an appropriate status is returned.  Use the
            clnt_perrno() routine to translate failure status into error messages.  Warning:
            rpc_call() uses the first available transport belonging to the class nettype, on
            which it can create a connection.  You do not have control of timeouts or
            authentication using this routine.

AVAILABILITY

     These functions are part of libtirpc.

SEE ALSO

     printf(3), rpc(3), rpc_clnt_auth(3), rpc_clnt_create(3)