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

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int
main(int argc, char **argv)
{
	fd_set readfds;
	int fd, ret;

	setprogname(argv[0]);
	if (argc != 2)
		errx(1, "Usage: %s <fd>", getprogname());
	fd = atoi(argv[1]);

	if (fcntl(fd, F_GETFL) != -1 || errno != EBADF)
		errx(1, "fd %d is already open", fd);

	FD_ZERO(&readfds);
	FD_SET(fd, &readfds);
	errno = 0;
	ret = select(fd + 1, &readfds, NULL, NULL, NULL);
	printf("ret=%d\nerrno=%d %s\n", ret, errno, strerror(errno));
	fflush(stdout);
	return ferror(stdout);
}