格式化時間字符串:
void get_time_str() {
time_t nowtime;
char time_string[16];
nowtime = time(NULL);
strftime(time_string, 16, "%b %d %H:%M:%S", localtime(&nowtime));
printf("Now time is %s\n", time_string);
}
取得時間差：
#define TV_SUBSTRACT(t2, t1) \
(double) (t2).tv_sec + (t2).tv_usec / 1000000.0 - \
(double) (t1).tv.sec + (t1).tv_usec / 1000000.0
void get_time_elapsed() {
struct timeval tv1, tv2;
int i;
gettimeofday(&tv1, NULL);
for (i=1; i< 100000; i++)
;
gettimeofday(&tv2, NULL);
printf("Elaspsed time is %.5f\n", TV_SUBSTRACT(tv2, tv1);
return;
}