Write a C program that illustrates inter process communication using shared memory system calls

Write a C program that illustrates inter process communication using shared memory system calls.


#include <stdio.h>
 #include<sys/ipc.h>
 #include<sys/shm.h>
 #include<sys/types.h>
 #define SEGSIZE 100
 int main(int argc, char *argv[ ])
 {
        int shmid,cntr;
        key_t key;
        char *segptr;
        char buff[ ]=”Hello world”;
        key=ftok(“.”,’s’);
        if((shmid=shmget(key, SEGSIZE, IPC_CREAT |
IPC_EXCL | 0666))= = -1)
        {
                if((shmid=shmget(key,SEGSIZE,0))= = -1)
                {
                      perror(“shmget”);
                      exit(1);
                }
        }
        else
        {
               printf(“Creating a new shared memory seg \n”);
               printf(“SHMID:%d”, shmid);
        }
        system(“ipcs –m”);
        if((segptr=shmat(shmid,0,0))= =(char*)-1)
       {
              perror(“shmat”);
              exit(1);
       }
       printf(“Writing data to shared memory…\n”);
       strcpy(segptr,buff);
       printf(“DONE\n”);
       printf(“Reading data from shared memory…\n”);
       printf(“DATA:-%s\n”segptr);
       printf(“DONE\n”);
       print(“Removing shared memory Segment…\n”);
       if(shmctl(shmid,IPC_RMID,0)= = -1)
             printf(“Can’t Remove Shared memory Segment…\n”);
      else
            printf(“Removed Successfully”);
 }