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

void alarm_hdl(int koko) {
  printf("Alarm! (%d)\n",koko);
  signal (SIGALRM,alarm_hdl);
}

main () {
  
  struct itimerval tvalue1;
  int i;
  int which;
  
  tvalue1.it_value.tv_sec=tvalue1.it_interval.tv_sec=0L;
  tvalue1.it_value.tv_usec= tvalue1.it_interval.tv_usec=500000;
  which=ITIMER_REAL;
  
  signal (SIGALRM,alarm_hdl);
  setitimer(which,&tvalue1,0);
  
  for(;;) {
    printf("Pausing..");
    fflush(stdout);
    pause();
  }
  
}