#include<stdlib.h>
#include<stdio.h>
#include<time.h>

main(int argc, char *argv[]) {
  unsigned int i,ii,iii,iv;
  double j;
  clock_t  start_ctime,finish_ctime; // used processor time
  time_t  s,f,t=time(NULL); // calender time
  if(argc!=2) { printf("usage: a.out sleeptime\n"); exit(1); }
  printf("CLOCKS_PER_SEC: %d\n",CLOCKS_PER_SEC);
  printf("%s",ctime(&t));
  start_ctime=clock(); s=time(NULL);
  for(i=0;i<10000;i++) 
    for(ii=1;ii<20;ii++)     
      for(iii=10;iii<20;iii++)
        for(iv=10;iv<20;iv++) 
          j=(i/ii/iii/iv);  
  printf("sleep %d secs....\n",atoi(argv[1]));
  sleep(atoi(argv[1]));
  finish_ctime=clock(); f=time(NULL);
  printf("%f[sec]\n%f[clockticks]\n%f[sec]\n",
         difftime(f, s),
         (double) (finish_ctime-start_ctime),
         ((double)(finish_ctime-start_ctime)/CLOCKS_PER_SEC));
}