// A demo of using signal handlers and alarm.

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/wait.h>

int beeps = 0;

void sig_handler(int signo) {
  printf("BEEP\n");
  if (++beeps < 5) {
    alarm(1); // schedule another SIGALRM
  } else {
    printf("DING DING!\n");
    exit(0);
  }
}


int main() {

  if (signal(SIGALRM, sig_handler) < 0) {
    printf("error installing handler\n");
    exit(1);
  }

  alarm(1); // send SIGALRM in 1 second

  while (1) {
    sleep(1); // sleep forever
  }

  return 0;
}