CODEWITHSUNDEEP
c++dateboost
Humble Debugger
Humble Debugger

Reputation: 4595

How to get current UTC date in boost?

Given this is a basic question, I imagine there might be duplicates, but I could not find any. I simply want to get the current iso_date ( like 20110503 ) from boost.

Any pointers ?

Upvotes: 8

Views: 15106

Answers (2)

Konrad Kleine
Konrad Kleine

Reputation: 4479

To print the current date and time in UTC, you can use this code (save as datetime.cpp):

#include <iostream>

// Not sure if this function is really needed.
namespace boost { void throw_exception(std::exception const & e) {} }

// Includes
#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/date_time/local_time_adjustor.hpp>
#include <boost/date_time/c_local_time_adjustor.hpp>

int main(int argc, char *argv[])
{
    // Code
    using boost::posix_time::ptime;
    using boost::posix_time::second_clock;
    using boost::posix_time::to_simple_string;
    using boost::gregorian::day_clock;

    ptime todayUtc(day_clock::universal_day(), second_clock::universal_time().time_of_day());
    std::cout << to_simple_string(todayUtc) << std::endl;

    // This outputs something like: 2014-Mar-07 12:56:55

    return 0;
}

Here's the CMake code to configure your build (save as CMakeLists.txt):

cmake_minimum_required(VERSION 2.8.8)

project(datetime)

find_package(Boost COMPONENTS date_time REQUIRED)
include_directories(${Boost_INCLUDE_DIRS})

add_executable(datetime datetime.cpp)

target_link_libraries(datetime ${Boost_LIBRARIES})

Put both files in a directory or clone my snippets using git clone https://gist.github.com/9410910.git datetime. To build the program run these commands: cd datetime && cmake . && make && ./datetime.

Here are my snippets: https://gist.github.com/kwk/9410910

I hope this is useful for somebody.

Upvotes: 11

ildjarn
ildjarn

Reputation: 62975

I assume you're looking for a Boost.Date_Time-based solution?

#include <locale>
#include <string>
#include <iostream>
#include <sstream>
#include <boost/date_time/gregorian/gregorian.hpp>

std::string utc_date()
{
    namespace bg = boost::gregorian;

    static char const* const fmt = "%Y%m%d";
    std::ostringstream ss;
    // assumes std::cout's locale has been set appropriately for the entire app
    ss.imbue(std::locale(std::cout.getloc(), new bg::date_facet(fmt)));
    ss << bg::day_clock::universal_day();
    return ss.str();
}

See Date Time Input/Output for more information on the available format flags.

Upvotes: 12

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