Shared Memory

Creating a shared memory using Server Process:

#include<sys/shm.h>
#include<sys/ipc.h>
#include<stdio.h>
#include<sys/types.h>
#include<stdlib.h>
#define SHMSZ 27
main()
{
char c;
int shmid;
key_t key;
char *shm,*s;
key=1004;
if((shmid=shmget(key,SHMSZ,IPC_CREAT|0666))<0)
{
perror("shmget");
exit(1);
}
if((shm=shmat(shmid,NULL,0))==(char *)-1)
{
perror("shmat");
exit(1);
}
s=shm;
for(c='a';c<='z';c++)
*s++=c;
*s='\0';
printf("Shared Memory Contents:%s\n",shm);
while(*shm!='*')
sleep(1);
printf("Shared Memory Contents:%s\n",shm);
exit(0);
}


Client Program:

#include<sys/shm.h>
#include<sys/ipc.h>
#include<stdio.h>
#include<sys/types.h>
#include<stdlib.h>
#define SHMSZ 27
main()
{
char c;
int shmid;
key_t; key
char *shm,*s;
key=1004;
if((shmid=shmget(key,SHMSZ,IPC_CREAT|0666))<0)
{
perror("shmget");
exit(1);
}
if((shm=shmat(shmid,NULL,0))==(char *)-1)
{
perror("shmat");
exit(1);
}
for(s=shm;*s!='\0';s++)
putchar('\n');
*shm='*';
exit(0);
}