timeval

timeval是一個專業術語。

問題描述

DESCRIPTION

The functions gettimeofday and settimeofday can get and set the time as

well as a timezone. The tv argument is a timeval struct, as specified

其中tv_usec代表的是微秒（百萬分之一秒）精度。

測試代碼

#include <stdio.h>

#include <sys/time.h>

int gettimeofday(struct timeval *tv, struct timezone *tz);

int main(int argc,char * argv[]){

struct timeval tv;

while(1){

gettimeofday(&tv,NULL);

printf("time %ld:%ld\n",tv.tv_sec,tv.tv_usec);

sleep(2);

}

return 0;

}

返回結果為：

evil@dcenter:~/tmp$ ./a.out

time 1142077839:903605

time 1142077841:910129

time 1142077843:920155

time 1142077845:930180

time 1142077847:940205

time 1142077849:950231

time 1142077851:960256

time 1142077853:970280

time 1142077855:980307

time 1142077857:990331

頭檔案： <sys/time.h>

timeval

{

time_t tv_sec; //秒 [long int]

suseconds_t tv_usec; //微秒 [long int]

};

成員：

tv_sec

秒

tv_usec

微秒