C/C++判断传入的UTC时间是否当天的实现方法

#include <iostream>
#include <time.h>

using namespace std;

bool IsInToday(long utc_time){

    time_t timeCur = time(NULL);
    struct tm curDate = *localtime(&timeCur);

    struct tm argsDate = *localtime(&utc_time);

    if (argsDate.tm_year == curDate.tm_year &&
        argsDate.tm_mon == curDate.tm_mon &&
        argsDate.tm_mday == curDate.tm_mday){
        return true;
    }

    return false;
}

std::string GetStringDate(long utc_time){

    struct tm *local = localtime(&utc_time);
    char strTime[50];
    sprintf(strTime,"%*.*d年%*.*d月%*.*d日",
            4,4,local->tm_year+1900,
            2,2,local->tm_mon+1,
            2,2,local->tm_mday);

    return strTime;
}

std::string GetStringTime(long utc_time){

    struct tm local = *localtime(&utc_time);
    char strTime[50];
    sprintf(strTime,"%*.*d:%*.*d:%*.*d",
            2,2,local.tm_hour,
            2,2,local.tm_min,
            2,2,local.tm_sec);
    return strTime;
}

void ShowTime(long utc_time){

    if (IsInToday(utc_time)){
        printf("%s\n",GetStringTime(utc_time).c_str());
    }else{
        printf("%s\n",GetStringDate(utc_time).c_str());
    }

}

int main(){

    ShowTime(1389998142);
    ShowTime(time(NULL));

    return 0;

}

bool IsInToday(long utc_time){

    time_t timeCur = time(NULL);
    struct tm* curDate = localtime(&timeCur);

    struct tm* argsDate = localtime(&utc_time);

    if (argsDate->tm_year == curDate->tm_year &&
        argsDate->tm_mon == curDate->tm_mon &&
        argsDate->tm_mday == curDate->tm_mday){
        return true;
    }

    return false;

}