A program to show how fork system call may be used with shared memory

/*A program to access perticular memory..& then print wt in this memory have or write in that memory*/

#include<stdio.h>

#include<stdlib.h>

#include<sys/types.h>

#include<sys/ipc.h>

#include<sys/shm.h>

int main()

{

    int ret,a=0;

    int* ptr;

    int kid;

    char i;

    kid=shmget(666,104,666|IPC_CREAT);

    printf("kid=%d\n",kid);

    if(kid<0)//if cant get shmid then goto OUT

        goto OUT;

    ptr=shmat(kid,(int*)0,0);//MEMORY is attached

    printf("shmat pt=%p\n",ptr);

        ret=fork();

    if(ret==0)

    {

    for(i='a';i<='z';i++)//all the values are put one by one into that memory

    {

    *(ptr+a)=i;//put value to address of pointer... not like this...->ptr=&i means putting address of i into ptr pointer

    printf("ent pt=%p\n",ptr+a);

    a++;

    }

    }

    else

    {

    sleep(15);

    a=0;

    for(a=0;a<26;a++)//all the values are put one by one into that memory

    {

    printf("print pt=%p\n",ptr+a);

        printf("ascii=%d\n",*(ptr+a));//print shared memory pointer

    }

    }

    return 0;

OUT:

    return -1;

}