在c++中是否有跨平台的方法来获取当前的日期和时间?


当前回答

下面是不弃用的现代c++解决方案,用于将时间戳作为std::string用于例如文件名:

std::string get_file_timestamp()
{
    const auto now = std::chrono::system_clock::now();
    const auto in_time_t = std::chrono::system_clock::to_time_t(now);

    std::stringstream output_stream;

    struct tm time_info;
    const auto errno_value = localtime_s(&time_info, &in_time_t);
    if(errno_value != 0)
    {
        throw std::runtime_error("localtime_s() failed: " + std::to_string(errno_value));
    }

    output_stream << std::put_time(&time_info, "%Y-%m-%d.%H_%M_%S");
    return output_stream.str();
}

其他回答

(给谷歌人)

还有Boost::date_time:

#include <boost/date_time/posix_time/posix_time.hpp>

boost::posix_time::ptime date_time = boost::posix_time::microsec_clock::universal_time();

localtime_s()版本:

#include <stdio.h>
#include <time.h>

int main ()
{
  time_t current_time;
  struct tm  local_time;

  time ( &current_time );
  localtime_s(&local_time, &current_time);

  int Year   = local_time.tm_year + 1900;
  int Month  = local_time.tm_mon + 1;
  int Day    = local_time.tm_mday;

  int Hour   = local_time.tm_hour;
  int Min    = local_time.tm_min;
  int Sec    = local_time.tm_sec;

  return 0;
} 

这适用于g++,我不确定这是否对你有帮助。 项目输出:

The current time is 11:43:41 am
The current date is 6-18-2015 June Wednesday 
Day of month is 17 and the Month of year is 6,
also the day of year is 167 & our Weekday is 3.
The current year is 2015.

代码:

#include <ctime>
#include <iostream>
#include <string>
#include <stdio.h>
#include <time.h>

using namespace std;

const std::string currentTime() {
time_t now = time(0);
struct tm tstruct;
char buf[80];
tstruct = *localtime(&now);
strftime(buf, sizeof(buf), "%H:%M:%S %P", &tstruct);
return buf;
}

const std::string currentDate() {
time_t now = time(0);
struct tm tstruct;
char buf[80];
tstruct = *localtime(&now);
strftime(buf, sizeof(buf), "%B %A ", &tstruct);
return buf;
}

int main() {
    cout << "\033[2J\033[1;1H"; 
std:cout << "The current time is " << currentTime() << std::endl;
    time_t t = time(0);   // get time now
    struct tm * now = localtime( & t );
    cout << "The current date is " << now->tm_mon + 1 << '-' 
         << (now->tm_mday  + 1) << '-'
         <<  (now->tm_year + 1900) 
         << " " << currentDate() << endl; 

 cout << "Day of month is " << (now->tm_mday) 
      << " and the Month of year is " << (now->tm_mon)+1 << "," << endl;
    cout << "also the day of year is " << (now->tm_yday) 
         << " & our Weekday is " << (now->tm_wday) << "." << endl;
    cout << "The current year is " << (now->tm_year)+1900 << "." 
         << endl;
 return 0;  
}

你可以尝试下面的跨平台代码来获取当前的日期/时间:

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

// Get current date/time, format is YYYY-MM-DD.HH:mm:ss
const std::string currentDateTime() {
    time_t     now = time(0);
    struct tm  tstruct;
    char       buf[80];
    tstruct = *localtime(&now);
    // Visit http://en.cppreference.com/w/cpp/chrono/c/strftime
    // for more information about date/time format
    strftime(buf, sizeof(buf), "%Y-%m-%d.%X", &tstruct);

    return buf;
}

int main() {
    std::cout << "currentDateTime()=" << currentDateTime() << std::endl;
    getchar();  // wait for keyboard input
}

输出:

currentDateTime()=2012-05-06.21:47:59

有关日期/时间格式的更多信息,请访问这里

这为我在Linux (RHEL)和Windows (x64)上编译,目标是g++和OpenMP:

#include <ctime>
#include <iostream>
#include <string>
#include <locale>

////////////////////////////////////////////////////////////////////////////////
//
//  Reports a time-stamped update to the console; format is:
//       Name: Update: Year-Month-Day_of_Month Hour:Minute:Second
//
////////////////////////////////////////////////////////////////////////////////
//
//  [string] strName  :  name of the update object
//  [string] strUpdate:  update descripton
//          
////////////////////////////////////////////////////////////////////////////////

void ReportTimeStamp(string strName, string strUpdate)
{
    try
    {
        #ifdef _WIN64
            //  Current time
            const time_t tStart = time(0);
            //  Current time structure
            struct tm tmStart;

            localtime_s(&tmStart, &tStart);

            //  Report
            cout << strName << ": " << strUpdate << ": " << (1900 + tmStart.tm_year) << "-" << tmStart.tm_mon << "-" << tmStart.tm_mday << " " << tmStart.tm_hour << ":" << tmStart.tm_min << ":" << tmStart.tm_sec << "\n\n";
        #else
            //  Current time
            const time_t tStart = time(0);
            //  Current time structure
            struct tm* tmStart;

            tmStart = localtime(&tStart);

            //  Report
            cout << strName << ": " << strUpdate << ": " << (1900 + tmStart->tm_year) << "-" << tmStart->tm_mon << "-" << tmStart->tm_mday << " " << tmStart->tm_hour << ":" << tmStart->tm_min << ":" << tmStart->tm_sec << "\n\n";
        #endif

    }
    catch (exception ex)
    {
        cout << "ERROR [ReportTimeStamp] Exception Code:  " << ex.what() << "\n";
    }

    return;
}