#include <stdio.h>
#include <stdlib.h>

#include <sys/select.h>
#include <errno.h>

#include <signal.h>

int
peek (int fd, int msec)
{
	fd_set readfds;
	fd_set exceptfds;
	struct timeval timeoutstru;

	FD_ZERO (& readfds);
	FD_SET (fd, & readfds);
	FD_ZERO (& exceptfds);
	FD_SET (fd, & exceptfds);
	timeoutstru.tv_sec = msec / 1000;
	timeoutstru.tv_usec = (msec % 1000) * 1000;

	errno = 0;
	printf ("calling select\n");
	int nfds = select (fd + 1, & readfds, 0, & exceptfds, & timeoutstru);
	printf ("select -> %d (%s), read %02X except %02X\n", 
		nfds, strerror (errno), readfds, exceptfds);

	return nfds;
}

void
catch_HUP (int hup)
{
	printf ("HUP\n");
	signal (SIGHUP, catch_HUP);
}

int
main ()
{
	int fdstdin = 0;

	system ("stty cbreak");
	signal (SIGHUP, catch_HUP);

	while (1) {
		char buf;
		int buflen = 1;

		int nfds = peek (fdstdin, 1500);
		if (nfds > 0) {
			printf ("calling read\n");
			errno = 0;
			int n = read (fdstdin, & buf, buflen);
			if (n <= 0) {
				printf ("read -> %d (%s); exit\n", n, strerror (errno));
				exit (0);
			}
			printf ("read -> %d: %c\n", n, buf);
		}
		sleep (2);
	}
}