#include	<stdio.h>
#include	<signal.h>
#include	<unistd.h>
#include	<stdlib.h>
/**
 **	signal sampler
 **
 **		short program to demonstrate how
 **		signals can kill a process, bounce off a process
 **		or be caught by a process
 **/

int main()
{
	void	catcher(int);		/* a function to call on CtrlC */
	int	i;

	signal(SIGFPE, on_fpe);
	printf("Case 1: no special arrangements..");
	for (i=0;i<10;i++){
		putchar('*');fflush(stdout);
		sleep(1);
	}
	putchar('\n');

	signal(SIGINT, SIG_IGN);	/* ignore INTerrupts	*/
	printf("Case 2: ignoring interrupts..");
	for (i=0;i<10;i++){
		putchar('*');fflush(stdout);
		sleep(1);
	}
	putchar('\n');

	signal(SIGINT, catcher);	/* handle interruptions	*/
	printf("Case 3: catching interrupts..");
	for (i=0;i<10;i++){
		putchar('*');fflush(stdout);
		sleep(1);
	}
	putchar('\n');
	return 0;
}

void catcher(int signum)
{
	printf(" Ouch! on signal %d\n", signum);
	printf("enter y to divide 3 by 0.0: ");
	if (getchar() == 'y' )
		int x =  3/0.0;
	system("who");
}

/* handler for floating point exception, e.g. divide by 0 */
void on_fpe(int signum)
{
	printf("Got a floating point exception!\n");
}