simpclient.c

this gives details of the network programming

/* RPC client for simple addition example */

#include <stdio.h>
#include "simp.h"  /* Created for us by rpcgen - has everything we need ! */

/* Wrapper function takes care of calling the RPC procedure */

int add( CLIENT *clnt, int x, int y) {
  operands ops;
  int *result;

  /* Gather everything into a single data structure to send to the server */
  ops.x = x;
  ops.y = y;

  /* Call the client stub created by rpcgen */
  result = add_1(&ops,clnt);
  if (result==NULL) {
    fprintf(stderr,"Trouble calling remote procedure\n");
    exit(0);
  }
  return(*result);
}

/* Wrapper function takes care of calling the RPC procedure */

int sub( CLIENT *clnt, int x, int y) {
  operands ops;
  int *result;

  /* Gather everything into a single data structure to send to the server */
  ops.x = x;
  ops.y = y;

  /* Call the client stub created by rpcgen */
  result = sub_1(&ops,clnt);
  if (result==NULL) {
    fprintf(stderr,"Trouble calling remote procedure\n");
    exit(0);
  }
  return(*result);
}


int main( int argc, char *argv[]) {
  CLIENT *clnt;
  int x,y;
  if (argc!=4) {
    fprintf(stderr,"Usage: %s hostname num1 num\n",argv[0]);
    exit(0);
  }

  /* Create a CLIENT data structure that reference the RPC
     procedure SIMP_PROG, version SIMP_VERSION running on the
     host specified by the 1st command line arg. */

  clnt = clnt_create(argv[1], SIMP_PROG, SIMP_VERSION, "udp");

  /* Make sure the create worked */
  if (clnt == (CLIENT *) NULL) {
    clnt_pcreateerror(argv[1]);
    exit(1);
  }

  /* get the 2 numbers that should be added */
  x = atoi(argv[2]);
  y = atoi(argv[3]);


  printf("%d + %d = %d\n",x,y, add(clnt,x,y));
  printf("%d - %d = %d\n",x,y, sub(clnt,x,y));
  return(0);
}