#include <stdio.h>
#include <unistd.h>
#include <poll.h>
#include <termios.h>
#include <sys/signalfd.h>
#include <sys/wait.h>

int run()
{
	struct termios tt;
	sigset_t sigset;
	pid_t pid;
	struct pollfd pfd[2];
	int running = 1;

	tcgetattr(STDIN_FILENO, &tt);
	tt.c_lflag &= ~(ECHO|ICANON|ISIG);
	tcsetattr(STDIN_FILENO, TCSANOW, &tt);

	pid = fork();
	if (pid == 0) {
		/* Child */
		usleep(100000);
		return 0;
	}
	printf("Start: %d\n", pid);

	sigemptyset(&sigset);
	sigaddset(&sigset, SIGCHLD);
	sigprocmask(SIG_BLOCK, &sigset, NULL);

	pfd[0].fd = STDIN_FILENO;
	pfd[0].events = POLLIN;
	pfd[1].fd = signalfd(-1, &sigset, 0);
	pfd[1].events = POLLIN;

	do {
		poll(pfd, 2, -1);
		if (pfd[0].revents & POLLIN) {
			char c;
			int ret = read(pfd[0].fd, &c, 1);
			if (ret == 0 || c == 'q' || c == '\003') {
				running = 0;
				break;
			}
		}
		if (pfd[1].revents & POLLIN) {
			struct signalfd_siginfo info;
			int ret = read(pfd[1].fd, &info, sizeof(info));
			if (ret) printf("Signal: %d\r\n", info.ssi_signo);
			if (info.ssi_signo == SIGCHLD) break;
		}
	} while (1);
	waitpid(pid, NULL, 0);
	printf("End: %d\n", pid);

	tcgetattr(STDIN_FILENO, &tt);
	tt.c_lflag |= ECHO|ICANON|ISIG;
	tcsetattr(STDIN_FILENO, TCSANOW, &tt);

	return running;
}

int main()
{
	while (run());
	return 0;
}