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

int fdTS[2], fdTC[2];

void pDie(int p)
{
	close(fdTS[0]);
	close(fdTS[1]);
	close(fdTC[0]);
	close(fdTC[1]);
	printf("\nBye Now\n");
	exit(0);
}

void chDie(int p)
{
	wait(0);
	signal(SIGCHLD, chDie);
}
int main()
{
	int ch;
	signal(SIGINT, pDie);
	signal(SIGCHLD, chDie);
	
	pipe(fdTS);
	pipe(fdTC);
	
	while(1)
	{
		ch = fork();
		if(ch == 0)
		{	
			printf("   ---- New child ----  \n");
			int ok = 1;
			while(ok)
			{
				int c;
				printf("Enter number:");
				scanf("%d", &c);
				write(fdTS[1], &c, sizeof(int));
				read(fdTC[0], &ok, sizeof(int));
			}
			int sum;
			read(fdTC[0], &sum, sizeof(int));
			printf("Sum: %d\n", sum);
			exit(0);
		}
		else if( ch  >  0)
		{	
			int numb = 0, sum = 0;
			do {
				sum = sum + numb;
				read(fdTS[0], &numb, sizeof(int));
				if(numb > 0)
				{
					int ok = 1;
					write(fdTC[1], &ok, sizeof(int));
				}

			}while(numb > 0);
			int ok = 0;
			write(fdTC[1], &ok, sizeof(int));
			write(fdTC[1], &sum, sizeof(int));
		}
	}
}