лабораторки по ОС препод Челноков / 2семестр / wi2 / AKAM / 1 / 1st

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/user.h>
#include <unistd.h>

int main()
{
char ch;
int pid1,pid2,dead1,dead2,status1,status2;
system("clear");
printf("Grand: PID: %d\n",getpid());
switch(pid1=fork())
{
case -1: printf("Error with fork Grand->Dad\n");exit(-1);
case  0: printf("Dad: PID: %d\n",getpid());
          switch(pid2=fork())
	{
	case -1: printf("Error with fork dad=>child\n");exit(-1);
	case  0: printf("Child: PID: %d\nPress any key to exit\n",getpid());
	ch=getchar();
	while (!ch)
		{
		ch=getchar();
		}
		exit(2);
	default: dead2=wait(&status2);
	}
printf("Child KILLED: PID was: %d; STATUS: %d\n",dead2,status2>>8);
exit(1);
default: dead1=wait(&status1);
}
printf("Dad KILLED: PID was: %d; STATUS: %d\n",dead1,status1>>8);
return 0;
}