/* getitimer.c
 *
 * Neal Nelson  2009.11.04
 *
 * Set and read the interval timer for real time.
 *
 */

#include <stdio.h>
#include <sys/time.h>

main()
{ struct itimerval itval;

  /* Initialize the real itimer to two seconds */

  itval.it_interval.tv_sec = 1;
  itval.it_interval.tv_usec = 999999;
  itval.it_value.tv_sec = 1;                /* why do I need to set value? */
  itval.it_value.tv_usec = 999999;          /* works only if I do */
  setitimer(ITIMER_REAL, &itval, NULL);


  /* read and display the real timer before sleep */

  if (getitimer(ITIMER_REAL, &itval) == 0 )
  { printf("Real Timer interval: %ld seconds, %ld microseconds\n",
            itval.it_interval.tv_sec, itval.it_interval.tv_usec);
    printf("   Real Timer value: %ld seconds, %ld microseconds\n",
            itval.it_value.tv_sec, itval.it_value.tv_usec);
  }
  

/*--------------------------------------------------------------------------*/
  printf("\nSleeping for one second\n\n");
  sleep(1);
/*--------------------------------------------------------------------------*/
  

  /* read and display the real timer after sleep */

  if (getitimer(ITIMER_REAL, &itval) == 0 )
  { printf("Real Timer interval: %ld seconds, %ld microseconds\n",
            itval.it_interval.tv_sec, itval.it_interval.tv_usec);
    printf("   Real Timer value: %ld seconds, %ld microseconds\n",
            itval.it_value.tv_sec, itval.it_value.tv_usec);
  }
  
}