Program For Calculating Factorial Using Remote Procedure Call (RPC)

Note:  Make Sure you had done following before proceeding

sudo apt-get install rpcbind

Then Create Directory With Any Name As Follow

mkdir rpcprogram

then in the directory using following command

cd rpcprogram

Follow the step as given below

1) Creating  file with .x  extension

I am using gedit editor

so

gedit fact.x

2) Add following code to fact.x


struct intpair 
{
int a;
};

program FACT_PROG 
{
version FACT_VERS 
{
int FACT(intpair) = 1;
} = 1;

} = 0x23451111;

Save and Exit File

3) We Need RPC to generate C Code to implement RPC protocol
use the following command with your .x file name

rpcgen -a -C fact.x


4) Edit the Makefile

gedit Makefile.fact


5) Search for following Lines in File

CFLAGS += -g

Change it to:

CFLAGS += -g -DRPC_SVC_FG


6) Again search the following and replace

RPCGENFLAGS =

Change it to:

RPCGENFLAGS = -C

# save and exit the file


7) Client program

gedit fact_client.c

(Note the changes in the following Program )

#include "fact.h"

void fact_prog_1(char *host,int a)
{
CLIENT *clnt;
int *result_1;
intpair fact_1_arg;
#ifndefDEBUG
clnt = clnt_create (host, FACT_PROG, FACT_VERS, "udp");
if (clnt == NULL)
{
clnt_pcreateerror (host);
exit (1);
}
#endif /* DEBUG */

fact_1_arg.a=a;
result_1 = fact_1(&fact_1_arg, clnt);
if (result_1 == (int *) NULL)
{
clnt_perror (clnt, "call failed");
}
else
{
printf("Factorial=%d",*result_1);
}

#ifndefDEBUG
clnt_destroy (clnt);
#endif /* DEBUG */
}
int main (int argc, char *argv[])
{
char *host;
int a,ch;
if (argc < 2)
{
printf ("usage: %s server_host\n", argv[0]);
exit (1);
}

host = argv[1];
do
{
system("clear");
printf("\nEnter a no:: ");
scanf("%d",&a);
fact_prog_1 (host,a);
printf("\nTry again : (1/0) :: ");
scanf("%d",&ch);
} while(ch==1);

exit (0);

}



8) Server Program

gedit fact_server.c

(Note the changes in the following Program )

#include "fact.h"

int *fact_1_svc(intpair *argp, struct svc_req *rqstp)

{

static int result,n,fact;

int i;

n=argp->a;

// factorial logic

fact = 1;

printf("\n Received : n= %d \n",n);

for (i=n;i>0;i--)

{

fact=fact * i;

}

result=fact;

return &result;

}

9) Run Programs 

# In terminal 1, run:

sudo ./fact_server

# In terminal 2, run:

./fact_client localhost

Output:

humble@humble-desktop:~$ cd exp2

humble@humble-desktop:~/exp2$ make -f Makefile.fact

cc -g -DRPC_SVC_FG -c -o fact_clnt.o fact_clnt.c

cc -g -DRPC_SVC_FG -c -o fact_client.o fact_client.c

cc -g -DRPC_SVC_FG -c -o fact_xdr.o fact_xdr.c

cc -g -DRPC_SVC_FG -o fact_client fact_clnt.o fact_client.o fact_xdr.o -lnsl

cc -g -DRPC_SVC_FG -c -o fact_svc.o fact_svc.c

cc -g -DRPC_SVC_FG -c -o fact_server.o fact_server.c

cc -g -DRPC_SVC_FG -o fact_server fact_svc.o fact_server.o fact_xdr.o -lnsl

humble@humble-desktop:~/exp2$

At server:

humble@humble-desktop:~$ cd exp2

humble@humble-desktop:~/exp2$ sudo ./fact_server

Received : n= 5

At client:

humble@humble-desktop:~$ cd exp2

humble@humble-desktop:~/exp2$ ./fact_client localhost

Enter a no:: 5

Factorial=120

Try again : (1/0) ::