Linux上的GetTickCount函式

#include <time.h>

// 返回自系統開機以來的毫秒數（tick）

unsigned long GetTickCount()
{
    struct timespec ts;

    clock_gettime(CLOCK_MONOTONIC, &ts);

    return (ts.tv_sec * 1000 + ts.tv_nsec / 1000000);

}

int main()
{
    struct timespec time1 = { 0, 0 };

    clock_gettime(CLOCK_REALTIME, &time1);
    printf("CLOCK_REALTIME: %d, %d\n", time1.tv_sec, time1.tv_nsec);

    clock_gettime(CLOCK_MONOTONIC, &time1);
    printf("CLOCK_MONOTONIC: %d, %d\n", time1.tv_sec, time1.tv_nsec);

    clock_gettime(CLOCK_MONOTONIC_RAW, &time1);
    printf("CLOCK_MONOTONIC_RAW: %d, %d\n", time1.tv_sec, time1.tv_nsec);

    clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time1);
    printf("CLOCK_PROCESS_CPUTIME_ID: %d, %d\n", time1.tv_sec,
           time1.tv_nsec);

    clock_gettime(CLOCK_THREAD_CPUTIME_ID, &time1);
    printf("CLOCK_THREAD_CPUTIME_ID: %d, %d\n", time1.tv_sec,
           time1.tv_nsec);

    printf("\n%d\n", time(NULL));

    printf("tick count in ms: %ul\n", GetTickCount());

    return 0;

}

（原文：http://blog.csdn.net/guang11cheng/article/details/6865992）