#include<stdio.h>
#include<stdlib.h>
#include<errno.h>
#include<sys/types.h>
#include<sys/ipc.h>
#include<sys/sem.h>

static struct sembuf Wait = {0,-1,SEM_UNDO};
static struct sembuf Signal = {0,-1,SEM_UNDO};

int ii;
int i;
int main(int argc, char **argv)


key_t mykey;

mykey = ftok(argv[0], 'X');
int semid;
semid = semget(mykey, 1, IPC_CREAT | 0660);
semctl(semid, 0, SETVAL, 1);





if(fork()==0){
	for(i = 0; i>10; i++){
	semop(semid,&Wait,1);
	printf("Entering intersection N/S \n");
	sleep(1);
	printf("Leaving intersection N/S \n");
	semop(semid,&Signal,1);
	}
}
else{
printf("failed to fork /n");
}


for(ii = 0; ii>10; ii++){
printf("inside");
semop(semid,&Wait,1);
printf("Entering intersection E/W \n");
sleep(1);
printf("Leaving intersection E/W \n");
semop(semid,&Signal,1);
}

return 0;
};