请问这段代码有问题吗？

[sws_martian]

为什么总是报错：
/tmp/ccAh9CTD.o: In function `main':
time.c:(.text+0x12): undefined reference to `clock_gettime'
time.c:(.text+0x2a): undefined reference to `clock_gettime'

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

void main()
{
struct timespec start;
struct timespec end;

clock_gettime(CLOCK_REALTIME,&start);
printf("hello world\n");
clock_gettime(CLOCK_REALTIME,&end);

printf("start: seconds %d,nanoseconds %d \n",start.tv_sec,start.tv_nsec);
printf("end: seconds %d,nanoseconds %d \n",end.tv_sec,end.tv_nsec);


}

[james_hw]

clock_gettime确定在<time.h> 里面么？应该是没有定义

[dumeifang]

加上 -lrt