Remote Procedure Call

RPC (Remote Procedure Call), it is higher level programming to socket programming.

.x files are just like Interface in java. 

conversion.x  

struct conv{  

float x;

};

program conversion{ 

version conversion1_vers{

int conversion1(conv)=1;

}=1;

version conversion2_vers{

int converions2(conv)=1;

}=2;

}= 0x23451111; 

In Conversion.x, conv is a structures used to send a float value.

To generate client and server code use rpcgen

rpcgen -a -C conversion.x

along with client and server, it will also generate makefile.conversion and someother files.

conversion_client.c

/*

 * This is sample code generated by rpcgen.

 * These are only templates and you can use them

 * as a guideline for developing your own functions.

 */

#include "conversion.h"

#include

#include /* getenv, exit */

void

conversion_1(float a,char *host)

{

CLIENT *clnt;

int  *result_1;

conv  conversion1_1_arg;

#ifndef DEBUG

clnt = clnt_create(host, conversion, conversion1_vers, "netpath");

if (clnt == (CLIENT *) NULL) {

clnt_pcreateerror(host);

exit(1);

}

#endif /* DEBUG */

conversion1_1_arg.x=a;

result_1 = conversion1_1(&conversion1_1_arg, clnt);

if (result_1 == (int *) NULL) {

clnt_perror(clnt, "call failed");

}

        else

        {

        printf("%.2f Kilometers is equal to %d Miles\n",a,*result_1);

        }

#ifndef DEBUG

clnt_destroy(clnt);

#endif /* DEBUG */

}

void

conversion_2(float a,char *host)

{

CLIENT *clnt;

int  *result_1;

conv  converions2_2_arg;

#ifndef DEBUG

clnt = clnt_create(host, conversion, conversion2_vers, "netpath");

if (clnt == (CLIENT *) NULL) {

clnt_pcreateerror(host);

exit(1);

}

#endif /* DEBUG */

converions2_2_arg.x=a;

result_1 = converions2_2(&converions2_2_arg, clnt);

if (result_1 == (int *) NULL) {

clnt_perror(clnt, "call failed");

}

        else

        {

        printf("%.2f Kilometers is equal to %d Feet\n",a,*result_1);

        }

#ifndef DEBUG

clnt_destroy(clnt);

#endif /* DEBUG */

}

main(int argc, char *argv[])

{

char *host;

float a;

if (argc <>

printf("usage:  %s server_host\n", argv[0]);

exit(1);

}

host = argv[1];

//According to your logic you need to write your code, here i put "a" as a parameter in both conversion_1 and conversion_2 inorder to send to server.

        printf("Enter kilometers\n");

        scanf("%f",&a);

conversion_1(a,host);

conversion_2(a,host);

}

conversion_server.c

/*

 * This is sample code generated by rpcgen.

 * These are only templates and you can use them

 * as a guideline for developing your own functions.

 */

#include "conversion.h"

#include

#include /* getenv, exit */

#include

#include

int *

//After generating this code, we need to write our definition to this methods.

conversion1_1_svc(conv *argp, struct svc_req *rqstp)

{

static int  result;

/*

* insert server code here

*/

        result=(int)floorf((argp->x/1.61)+0.5);

        printf("1st resutl is %d\n",result);

return (&result);

}

int *

converions2_2_svc(conv *argp, struct svc_req *rqstp)

{

static int  result;

/*

* insert server code here

*/

result=(int)floorf(((argp->x) * 3280.839895)+0.5);

        printf("2nd result is %d\n",result);

return (&result);

}

Change the make.conversion to makefile.

mv makefile.conversion makefile

in makefile you need to change the following.

CC=gcc  // default is cc

CFLAGS += -g -DRPC_SVC_FG

RPCGENFLAGS = -C

To compile

$ make

Open two command prompts, one for server and other for client.

$./conversion_server

$./conversion_client