blog de bonarbo

time_t time(  
   time_t *timer   
);  

struct tm *localtime(  
   const time_t *timer
); 

struct tm *gmtime(    
 const time_t *timer   
); 

time_t mktime(
     struct tm *timeptr   
);  

Unix time ( = POSIX time, Epoch time)

time_t local_time;
time ( &local_time );

struct tm *local_tm = localtime(&local_time);

// local_tm: 2016-12-14 11:33:8

struct tm *utc_tm = gmtime(&local_time); 

// utc_tm: 2016-12-14 2:33:8
// local_tm: 2016-12-14 2:33:8 // 내부적으로 같은 정보를 가르키고 있어서, 값이 함께 바뀜

DebugLog("local_tm: %d-%d-%d %d:%d:%d\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);