From chrome://newtab/

clock_get

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

#define MILLION 1000000

long clock_get()
{
	long ret;
	struct timespec t;
	clock_gettime(CLOCK_MONOTONIC, &t);
	ret = t.tv_sec * MILLION + t.tv_nsec/1000;
	return ret;
}

long calcu(long start, long end)
{
	long r = (end - start)/1000;
	return r;
}

int main(void)
{
	long int loop = 1000;
	long start;
	long end;
	long timedif;

	start = clock_get();

	while (--loop){
		system("cd");
	}
	end = clock_get();
	timedif = calcu(start, end);
	fprintf(stdout, "it took %ld milliseconds\n", timedif);

	return 0;
}