Has anybody ever implimented a to_time_t function/method for the ptime class to create a time_t from a ptime. I tried doing it similar to the way from_time_t does it but I'm not getting the right answer. It's nice that you can convert from a time_t for use with legacy code but sometimes you need to go back the other way. Herer is my to_time_t function that does not appear to be working inline std::time_t to_time_t(ptime t) { if( t == neg_infin ) return 0; else if( t == pos_infin ) return LONG_MAX; ptime start(gregorian::date(1970,1,1),time_duration(0,0,0)); return (t-start).total_seconds(); } Thanks,
On Thu, 22 Jul 2004 07:45:15 -0700, Matt Schuckmann wrote
Has anybody ever implimented a to_time_t function/method for the ptime class to create a time_t from a ptime. I tried doing it similar to the way from_time_t does it but I'm not getting the right answer.
It's nice that you can convert from a time_t for use with legacy code but sometimes you need to go back the other way.
Herer is my to_time_t function that does not appear to be working inline std::time_t to_time_t(ptime t) { if( t == neg_infin ) return 0; else if( t == pos_infin ) return LONG_MAX; ptime start(gregorian::date(1970,1,1),time_duration(0,0,0)); return (t-start).total_seconds(); }
Odd. It works fine for me. Here's my slightly cleaned up version with command line interface for testing: #include "boost/date_time/posix_time/posix_time.hpp" #include <string> #include <iostream> using namespace boost::posix_time; using namespace boost::gregorian; inline std::time_t to_time_t(ptime t) { if( t == neg_infin ) return 0; else if( t == pos_infin ) return LONG_MAX; ptime start(date(1970,1,1)); return (t-start).total_seconds(); } int main() { std::cout << "***** Time_t calculator *****" << std::endl; std::cout << "Enter a time as in yyyy-mm-dd hh:mm:ss format" << std::endl; std::cout << "For example: 2003-3-25 00:55:26" << std::endl; std::cout << "Time: "; std::string ts; std::getline(std::cin, ts); ptime t2 = time_from_string(ts); std::cout << "seconds since 1/1/1970: " << to_time_t(t2) << std::endl; } Couple of runs: ***** Time_t calculator ***** Enter a time as in yyyy-mm-dd hh:mm:ss format For example: 2003-3-25 00:55:26 Time: 2003-3-25 00:56:26 seconds since 1/1/1970: 1048553786 ***** Time_t calculator ***** Enter a time as in yyyy-mm-dd hh:mm:ss format For example: 2003-3-25 00:55:26 Time: 1970-1-1 0:0:1 seconds since 1/1/1970: 1 What is your environment (compiler, boost version, etc)? Jeff
You are right it does work however I've got another problem. The standard ::ctime function takes a time_t adjusts for the local time zone and converts it to printable string, There doesn't appear to be an equivalent for the ptime, ie I haven't been able to figure out how to create a ptime object from a time_t, adjust it for the local time zone and generate a printable string that shows the correct time for this the local time zone. It's almost like you need another parameter for from_time_t() or to_??_string() to indicated if it's local time or UTC time or ? That or some other flag or operation to indicate that a ptime is in UTC time and you want to convert it into local time. Am I making sense here? Does this seem reasonable? I was also wondering if you plan to impliment any more options for converting to and from strings to ptime's. You've implimented a rather limited set. It would be especially nice if you implimented a format type function that works like strftime(). Matt S. "Jeff Garland" <jeff@crystalclearsoftware.com> wrote in message news:20040723002145.M7047@crystalclearsoftware.com...
On Thu, 22 Jul 2004 07:45:15 -0700, Matt Schuckmann wrote
Has anybody ever implimented a to_time_t function/method for the ptime class to create a time_t from a ptime. I tried doing it similar to the way from_time_t does it but I'm not getting the right answer.
It's nice that you can convert from a time_t for use with legacy code but sometimes you need to go back the other way.
Herer is my to_time_t function that does not appear to be working inline std::time_t to_time_t(ptime t) { if( t == neg_infin ) return 0; else if( t == pos_infin ) return LONG_MAX; ptime start(gregorian::date(1970,1,1),time_duration(0,0,0)); return (t-start).total_seconds(); }
Odd. It works fine for me. Here's my slightly cleaned up version with command line interface for testing:
#include "boost/date_time/posix_time/posix_time.hpp" #include <string> #include <iostream>
using namespace boost::posix_time; using namespace boost::gregorian;
inline std::time_t to_time_t(ptime t) { if( t == neg_infin ) return 0; else if( t == pos_infin ) return LONG_MAX; ptime start(date(1970,1,1)); return (t-start).total_seconds(); }
int main() { std::cout << "***** Time_t calculator *****" << std::endl; std::cout << "Enter a time as in yyyy-mm-dd hh:mm:ss format" << std::endl; std::cout << "For example: 2003-3-25 00:55:26" << std::endl; std::cout << "Time: "; std::string ts; std::getline(std::cin, ts); ptime t2 = time_from_string(ts); std::cout << "seconds since 1/1/1970: " << to_time_t(t2) << std::endl; }
Couple of runs:
***** Time_t calculator ***** Enter a time as in yyyy-mm-dd hh:mm:ss format For example: 2003-3-25 00:55:26 Time: 2003-3-25 00:56:26 seconds since 1/1/1970: 1048553786
***** Time_t calculator ***** Enter a time as in yyyy-mm-dd hh:mm:ss format For example: 2003-3-25 00:55:26 Time: 1970-1-1 0:0:1 seconds since 1/1/1970: 1
What is your environment (compiler, boost version, etc)?
Jeff
participants (6)
-
Jeff Garland -
Matt Schuckmann