C語言 文件中時間與當前系統時間 時間差比較（比較結果返回為天數）最好是調用子函數解決

#include?<stdlib.h>

#include?<time.h>

int?days(char*?begin_time)//格式:?"20180914000000"?//2018-9-14?0點0分0秒?

{

struct?tm?tm1;

time_t?time1,time_now;

sscanf(begin_time,"%4d%2d%2d%2d%2d%2d",&tm1.tm_year,&tm1.tm_mon,&tm1.tm_mday,&tm1.tm_hour,&tm1.tm_min,&tm1.tm_sec);

tm1.tm_year-=1900;

tm1.tm_mon--;

tm1.tm_isdst=-1;

time1=mktime(&tm1);?//構造time1?

time_now=time(NULL);

tm1=*(localtime(&time_now));?//當時日期

return?(time_now-time1)/(3600*24);?//返回相差天數?

}

int?main()

{

char?time_in_file[30]={"20180914000000\0"};

printf("\n%d",days(time_in_file));

return?0;

}