/*
 * Operating Systems Class
 * Fall 2006, Professor Yap.
 * 	THIS code is adapted from the website
 *	http://beige.ucs.indiana.edu/B673/node104.html by Zdzislaw Meglicki
 */
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
#include <stdio.h>
#include <math.h>

main()
{
  time_t  t0, t1; 
  clock_t c0, c1;

  long count;
  double a, b, c;

  t0 = time(NULL);
  c0 = clock();

  printf ("\tbegin time in sec:          %ld\n", (long) t0);
  printf ("\tbegin clock ticks:           %d\n", (int) c0);
  printf ("\t\tsleep for 2 seconds ... \n");
  sleep(2);

  printf ("\t\tperform some computation ... \n");
  for (count = 1l; count < 10000000l; count++) {
     a = sqrt(count); b = 1.0/a; c = b - a;
  }

  t1 = time(NULL);
  c1 = clock();

  printf ("\tend time in sec:              %ld\n", (long) t1);
  printf ("\tend clock ticks:              %d\n", (int) c1);
  printf ("\telapsed elapsed time in sec:  %ld\n", (long) (t1 - t0));
  printf ("\telapsed elapsed ticks in sec: %f\n",
  			(float) (c1 - c0)/CLOCKS_PER_SEC);
}