#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<string.h>
#include<sys/ipc.h>
#include<sys/shm.h>
#include<sys/stat.h>


#define ERROR (void *) -1

void error(const char *string)
{
		perror(string);
		_exit(1);
}

int main(int argc , char *argv[])
{
		char *addr; /*shared memory addre */
		char replay[] = "Ok I Got It\n";

		int key;
		int z;

		if(argc < 2)
		{
				printf("Usage %s Key\n",argv[0]);
				_exit(0);
		}

		key = atoi(argv[1]);
		printf("[+]Starting\n"
						"[+]Got Key %d\n",key);
		addr = shmat(key , NULL , 0);
		if(addr == ERROR)
		{
				error("[!]Shmat()");
		}

		printf("[+]Memory Attached\n");
		printf("Address %p has %s\n",addr , addr);

		printf("[+]Writing To Memory\n");

		memcpy(addr , replay , sizeof(replay));

		printf("[+]Detach\n");

		z = shmdt(addr);
		if(z < 0)
		{
				error("[!]Shmdt()");
		}

		_exit(0);
}

#include<stdio.h>
#include<unistd.h>
#include<stdlib.h>
#include<string.h>
#include<sys/shm.h>
#include<sys/ipc.h>
#include<sys/stat.h>
#include<sys/wait.h>

#define ERROR (void *) -1

int main(int argc , char *argv[])
{
		char *addr;
		char hello[] = "St0rM-Memories\n";

		struct shmid_ds buffer;
		int seg_size;
		int seg_id;
		int z;

		pid_t chpid;
		int stat;

		char *args[2];

		if(argc < 2)
		{
				printf("Usage %s client\n",argv[0]);
				_exit(0);
		}

		args[0] = strdup(argv[1]); /*copy program name*/

		printf("[+]Staring\n");

		seg_id = shmget(IPC_PRIVATE , 0x6400 , IPC_CREAT | IPC_EXCL |
												S_IRUSR | S_IWUSR );
		if(seg_id < 0)
		{
				perror("[!]ShmGet()");
				_exit(1);
		}

		printf("[+]Memory Creating Attaching Now\n");

		args[1] = malloc(sizeof(int));
		sprintf(args[1] , "%d" ,seg_id);

		addr = shmat(seg_id , NULL , 0);

		if(addr == ERROR )
		{
				perror("[!]ShmAt()");
				_exit(1);
		}

		printf("[+]Memory Attached\n");

		z = shmctl(seg_id , IPC_STAT , &buffer);
		if(z < 0)
		{
				perror("[!]ShmCtl");
				_exit(1);
		}
		printf("Memory At %p Size = %d\n", addr ,buffer.shm_segsz);

		memcpy(addr , hello , sizeof(hello));

		printf("[+]Running %s with id %s Now\n",args[0], args[1]);

		chpid = fork();

		if(chpid == -1)
		{
				perror("[!]Fork()");
				_exit(1);
		}else if(chpid == 0)
		{
				execvp(argv[1], args);

				perror("[!]execvp()");
				_exit(1);
		}
		else
		{
				z = shmctl(seg_id , IPC_STAT , &buffer);
				if(z < 0)
				{
						perror("[!]Shmctl()");
						_exit(1);
				}
				printf("Currently Attached Processes %d\n",buffer.shm_nattch);
				wait(&stat); /*wait for child*/
		}

		printf("Memory %p Has %s\n",addr , addr);

		z = shmctl(seg_id , IPC_RMID , NULL);
		if(z < 0)
		{
				perror("[!]Shmctl()");
				_exit(1);
		}

		printf("[+]Job Complete\n");
		return 0;
}

man ipcs
man ipcrm