#define _GNU_SOURCE
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <error.h>
#include <stdlib.h>

int main(void)
{
	int shmid = -1;
	char *result;
	
	shmid = shmget(IPC_PRIVATE, 1024*1024, IPC_CREAT|0700);

	if(shmid == -1) {
		error(0, errno, "shmget");
		exit(1);
	}

	result = (char *)shmat(shmid, NULL, 0);

	if(result == (char *)-1) {
		int save_errno = errno;
		if(shmctl(shmid, IPC_RMID, NULL) == -1) {
			error(0, errno, "shmctl");
		}

		error(0, save_errno, "shmat");
		exit(1);
	}

	sleep(5);
	
	if(shmctl(shmid, IPC_RMID, NULL) == -1) {
		error(0, errno, "shmctl");
		exit(1);
	}

	if(shmdt(result) == -1) {
		error(0, errno, "shmdt");
		exit(1);
	}

	exit(0);
}