#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>

int main(void)
{
	char pid[10];
	sprintf(pid, "%d", getpid());
	int myPID = getpid();
	printf("Parent PID: %d\n", getpid()); //P

	if (fork() == 0) //P1
	{
		printf("1 PID: %d, PPID: %d\n", getpid(), getppid());

		if (fork() == 0) //P1A
		{
			printf("1A PID: %d, PPID: %d\n", getpid(), getppid());
			if (fork() == 0) //P1AA
			{
				printf("1AA PID: %d, PPID: %d\n", getpid(), getppid());
				sleep(2);
				return 0;
			}
			sleep(2);
			return 0;
		}
		sleep(2);
		return 0;
	}


	if (fork() == 0) //P2
	{
		printf("2 PID: %d, PPID: %d\n", getpid(), getppid());

		if (fork() == 0) //P2A
		{
			printf("2A PID: %d, PPID: %d\n", getpid(), getppid());
			if (fork() == 0) //P2AA
			{
				printf("2AA PID: %d, PPID: %d\n", getpid(), getppid());
				sleep(2);
				return 0;
			}
			execlp("pstree", "pstree", "-c", pid, (char*)NULL); //pstree
			sleep(2);
			return 0;
		}

		if (fork() == 0) //P2B
		{
			printf("2B PID: %d, PPID: %d\n", getpid(), getppid());

			if (fork() == 0) //P2BA
			{
				printf("2BA PID: %d, PPID: %d\n", getpid(), getppid());
				sleep(2);
				return 0;
			}

			if (fork() == 0) //P2BB
			{
				printf("2BB PID: %d, PPID: %d\n", getpid(), getppid());
				sleep(2);
				return 0;
			}
			sleep(2);
			return 0;
		}

		if (fork() == 0) //P2C
		{
			printf("2C PID: %d, PPID: %d\n", getpid(), getppid());
			sleep(2);
			return 0;
		}
	}
	sleep(2);
	return 0;
}