arpserver.c
#include<stdio.h>
#include<sys/types.h>
#include<sys/shm.h>
#include<string.h>
main()
{
int shmid,a,i;
char *ptr,*shmptr;
shmid=shmget(3000,10,IPC_CREAT|0666);
shmptr=shmat(shmid,NULL,0);
ptr=shmptr;
for(i=0;i<3;i++)
{
puts("Enter the name:");
scanf("%s",ptr);
a=strlen(ptr);
printf("String length:%d",a);
ptr[a]=' ';
puts("Enter ip:");
ptr=ptr+a+1;
scanf("%s",ptr);
ptr[a]='\n';
ptr=ptr+a+1;
}
ptr[strlen(ptr)]='\0';
printf("\nARP table at serverside is=\n%s",shmptr);
shmdt(shmptr);
}

arpclient.c
#include<stdio.h>
#include<string.h>
#include<sys/types.h>
#include<sys/shm.h>
main()
{
int shmid,a;
char *ptr,*shmptr;
char ptr2[51],ip[12],mac[26];
shmid=shmget(3000,10,0666);
shmptr=shmat(shmid,NULL,0);
puts("The ARPtable is:");
printf("%s",shmptr);
printf("\n1.ARP\n2.RARP\n3.EXIT\n");
scanf("%d",&a);
switch(a)
{
case 1:
puts("Enter ip address:");
scanf("%s",ip);
ptr=strstr(shmptr,ip);
ptr-=8;
sscanf(ptr,"%s%*s",ptr2);
printf("mac addr is:%s",ptr2);
break;
case 2:
puts("Enter mac addr");
scanf("%s",mac);
ptr=strstr(shmptr,mac);
sscanf(ptr,"%*s%s",ptr2);
printf("%s",ptr2);
break;
case 3:
exit(1);
}
}