Example of using libC clock() function.

clock.c

/*
 *
 * Compile with: `gcc -o clock clock.c`
 *
 * [clock(3) - Linux man page](http://linux.die.net/man/3/clock): *The value returned is the CPU time used [by the process] so far[...]*
 * [What’s the correct way to use printf to print a clock_t?](http://stackoverflow.com/questions/1083142/what-s-the-correct-way-to-use-printf-to-print-a-clock-t)
 *
 */

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

int main(int argc, char **argv){
  clock_t j;

  j = clock();
  printf("clock(): %ju\n", (uintmax_t)j );
}