#include <err.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>

static void
handler(int signo)
{
}

int
main(int argc, char *argv[])
{
	sigset_t mask, oldmask;
	struct sigaction sa;

	memset(&sa, 0, sizeof(sa));
	sa.sa_handler = handler;
	if (sigaction(SIGINT, &sa, NULL) == -1)
		err(1, "sigaction");
	sigemptyset(&mask);
	sigaddset(&mask, SIGINT);
	sigprocmask(SIG_BLOCK, &mask, &oldmask);
	while (sigsuspend(&oldmask))
		printf("got signal errno %d\n", errno);

	return (0);
}