struct tm localtime(time_t * _Time):將UTC的秒數轉化爲年(since1900)、月([0-11])、日、時、分、秒
time_t mktime(strcut tm * timeptr):將struct tm轉化爲time_t
#include <stdio.h>
#include <time.h>
{
time_t tm;
struct tm *local_tm;
printf("sec1 = %d\n", (long)tm);
local_tm = localtime(&tm);
printf("%4d-%02d-%02d %02d:%02d:%02d\n", (local_tm->tm_year+1900), (local_tm->tm_mon+1),
local_tm->tm_mday,local_tm->tm_hour, local_tm->tm_min, local_tm->tm_sec);
printf("sec2 = %d\n", (long)tm);
}
編譯結果:
sec1 = 1515406808
2018-01-08 18:20:08
sec2 = 1515406808
請按任意鍵繼續. . .
int clock_gettime(clockid_t clk_id, struct timespec *tp);
a、CLOCK_REALTIME:系統實時時間,隨系統實時時間改變而改變
b、CLOCK_MONOTONIC,從系統啓動這一刻起開始計時,不受系統時間被用戶改變的影響
c、CLOCK_PROCESS_CPUTIME_ID,本進程到當前代碼系統CPU花費的時間
d、CLOCK_THREAD_CPUTIME_ID,本線程到當前代碼系統CPU花費的時間
{
time_t tv_sec; /* 秒*/
long tv_nsec; /* 納秒*/
};