#include <stdio.h>
#include <err.h>
#include <unistd.h>

static char buf[65536];

int main()
{
	pid_t child;
	int status;
	int p[2],q[2];
	int i;
	char ch;

	if (pipe(p) == -1)
		err(1,"pipe");
	if (pipe(q) == -1)
		err(1,"pipe");

	child = fork();
	if (child == -1)
		err(1,"fork");

	if (child == 0) {
		close(p[0]);
		close(q[1]);
		i = 0;
		while (i++<1000000 && read(0,buf,sizeof(buf)) == sizeof(buf)) {
			write(p[1],&ch,1);
			if (read(q[0],&ch,1) != 1)
				break;
		}
		_exit(0);
	}
	close(p[1]);
	close(q[0]);

	while (read(p[0],&ch,1) == 1) {
		write(q[1],&ch,1);
	}

	wait(&status);

	return 0;
}