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

/* This flag controls termination of the main loop.  */
volatile sig_atomic_t keep_going = 1;

/* The signal handler just clears the flag and re-enables itself.  */
	void 
catch_alarm (int sig)
{
	keep_going = 0;
	puts("ALARM");
	signal (sig, catch_alarm);
}

	void 
do_stuff (void)
{
	puts ("Doing stuff while waiting for alarm....");
}

	int
main (void)
{
	/* Establish a handler for SIGALRM signals.  */
	signal (SIGALRM, catch_alarm);

	/* Set an alarm to go off in a little while.  */
	alarm (2);

	/* Check the flag once in a while to see when to quit.  */
	while (keep_going)
		do_stuff ();

	return EXIT_SUCCESS;
}