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


struct timeval tv1, tv2, stv, etv;
struct timezone tz;

void
waitTime(int time) {
   (void) gettimeofday(&tv1, &tz);
   while (1) {
   (void) gettimeofday(&tv2, &tz);
   if ((tv2.tv_sec-tv1.tv_sec)*1000000+(tv2.tv_usec-tv1.tv_usec)- time>=-4) 
      break;
   } 
}

main() {
   int time, diff;
   int i;
   for (i=0; i<100 & time > 0; i++) {
   printf("enter usec number to be wait:\n");
   scanf("%d", &time); 
   printf("time=%d\n", time);

   (void) gettimeofday(&stv, &tz);
    
   waitTime(time);
   (void) gettimeofday(&etv, &tz);
   diff= (etv.tv_sec-stv.tv_sec)*1000000+(etv.tv_usec-stv.tv_usec);
    
   printf("wait %dusec, diff=%dusec, stv=%d.%d, etv=%d.%d\n", time, diff, stv.tv_sec, stv.tv_usec, etv.tv_sec, etv.tv_usec) ;

   }
}