//Declaration: double difftime(time_t time2, time_t time1);
#include
#include
int main(void)
{
time_t start, end;
volatile long unsigned t;
start = time(NULL);
for(t=0; t<500; t++) ;
end = time(NULL);
printf("Loop used %f seconds.\n", difftime(end, start));
return 0;
}
/*
Loop used 0.000000 seconds.
*/