Question

是否有将日期时间字符串转换为纪元时间（以秒为单位）的C / C ++ / STL / Boost清理方法？

yyyy:mm:dd hh:mm:ss

Answer 1

请参阅：Date/time conversion: string representation to time_t

并且：[Boost-users] [date_time] So how come there isn't a to_time_t helper func?

所以，显然这样的事情应该有效：

#include <boost/date_time/posix_time/posix_time.hpp>
using namespace boost::posix_time;

std::string ts("2002-01-20 23:59:59");
ptime t(time_from_string(ts));
ptime start(gregorian::date(1970,1,1)); 
time_duration dur = t - start; 
time_t epoch = dur.total_seconds();

但我认为它不比Rob's suggestion更清晰：使用sscanf将数据解析为struct tm，然后调用mktime。

Answer 2

在Windows平台上，如果不想使用Boost，可以执行以下操作：

// parsing string
SYSTEMTIME stime = { 0 };
sscanf(timeString, "%04d:%02d:%02d %02d:%02d:%02d",
       &stime.wYear, &stime.wMonth,  &stime.wDay,
       &stime.wHour, &stime.wMinute, &stime.wSecond);

// converting to utc file time
FILETIME lftime, ftime;
SystemTimeToFileTime(&stime, &lftime);
LocalFileTimeToFileTime(&lftime, &ftime);

// calculating seconds elapsed since 01/01/1601
// you can write similiar code to get time elapsed from other date
ULONGLONG elapsed = *(ULONGLONG*)&ftime / 10000000ull;

如果您更喜欢标准库，可以使用struct tm和mktime（）来完成相同的工作。

Answer 3

http://www.boost.org/doc/libs/1_39_0/doc/html/date_time.html 应该做的伎俩。

C ++干净地将Datetime字符串转换为Epoch

3 个答案: