difftime

函数名: difftime

功 能: 计算两个时刻之间的时间差

用 法: double difftime(time_t time2, time_t time1);

程序例:

#include <time.h>

#include <stdio.h>

#include <dos.h>

#include <conio.h>

int main(void)

{

time_t first, second;

clrscr();

first = time(NULL); /* Gets system

time */

delay(2000); /* Waits 2 secs */

second = time(NULL); /* Gets system time

again */

printf("The difference is: %f

seconds

",difftime(second,first));

getch();

return 0;

}