c c 時間函式學習筆記

#include #include #include #include #include using namespace std;

int main(int argc, char * ar**)
// for debug
/*for (vector::iterator it = time.begin(); it != time.end(); it++)
*/// 將tm結構時間轉化為time_t時間
cout << time1[0] << endl;
struct tm *time_info2 = null;
time_info2 = (struct tm*)malloc(sizeof(struct tm));
time_info2->tm_year = time1[0] - 1900;
time_info2->tm_mon = time1[1] - 1;
time_info2->tm_mday = time1[2];
time_info2->tm_hour = time1[3];
time_info2->tm_min = time1[4];
time_info2->tm_sec = time1[5];
time_info2->tm_isdst = 0; //夏令時識別符號也需要賦值，否則會出錯
printf( "the time is %4d_%02d_%02d_%02d_%02d_%02d\n", time_info2->tm_year+1900, time_info2->tm_mon+1, \
time_info2->tm_mday, time_info2->tm_hour, time_info2->tm_min, time_info2->tm_sec);
time_t cur_time2;
cur_time2 = mktime(time_info2);
cout << "the current time is " << cur_time2 << endl;
sleep(2);
time_t raw_time3;
raw_time3 = time(nullptr);
cout << raw_time3 << endl;
// difftime 比較兩個時間相差的秒數，前面的秒數比後面大，則返回正數，否則返回負數
double seconds = difftime(raw_time3, cur_time2);
cout << "the seconds is " << seconds << endl;
free(time_info2);
}

執行結果如下：

the raw_time is 1550243429

the time buffer is 2019_02_15_23_10_29
2019
0215
2310
292019
the time is 2019_02_15_23_10_29
the current time is 1550243429
1550243431
the seconds is 2

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