프로그램 수행 시 수행 시간 측정

출처: http://stackoverflow.com/questions/588307/c-obtaining-milliseconds-time-on-linux-clock-doesnt-seem-to-work-properl

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

#include <stdio.h>
#include <unistd.h>
int main()
{
    struct timeval start, end;

    long mtime, seconds, useconds;    

    gettimeofday(&start, NULL);
    usleep(2000);
    gettimeofday(&end, NULL);

    seconds  = end.tv_sec  - start.tv_sec;
    useconds = end.tv_usec - start.tv_usec;

    mtime = ((seconds) * 1000 + useconds/1000.0) + 0.5;

    printf("Elapsed time: %ld milliseconds\n", mtime);

    return 0;
}