signal_3.c

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

#define IGNORE_ALL_SIGNALS 1

void signal_loop(int sig);

int main(int argc, char **argv)
{

#ifdef IGNORE_ALL_SIGNALS
	sigset_t mask;
	sigfillset(&mask);	
	sigprocmask(SIG_SETMASK, &mask, NULL);
#else
	signal(SIGQUIT, signal_loop);
#endif

	printf("Entering loop waiting for -3 signal...\n");

	for(;;)
	{
		sleep(1);
	}

	return 0;
}

void signal_loop(int sig)
{
	printf("Caught -3 SIQQUIT, press enter to continue.\n");
	getchar();
	exit(0);
}