Function write_time_tests

test/operations_test.cpp:1604–1641

  //  write_time_tests  ----------------------------------------------------------------//

  void write_time_tests(const fs::path& dir)
  {    
    cout << "write_time_tests..." << endl;

    fs::path f1 = dir / "foobar2";
    create_file(f1, "foobar2");
    BOOST_TEST(fs::exists(f1));
    BOOST_TEST(!fs::is_directory(f1));
    BOOST_TEST(fs::is_regular_file(f1));
    BOOST_TEST(fs::file_size(f1) == 7);
    verify_file(f1, "foobar2");

    // Some file system report last write time as local (FAT), while
    // others (NTFS) report it as UTC. The C standard does not specify
    // if time_t is local or UTC. 

    std::time_t ft = fs::last_write_time(f1);
    cout << "\n  UTC last_write_time() for a file just created is "
      << std::asctime(std::gmtime(&ft)) << endl;

    std::tm * tmp = std::localtime(&ft);
    cout << "\n  Year is " << tmp->tm_year << endl;
    --tmp->tm_year;
    cout << "  Change year to " << tmp->tm_year << endl;
    fs::last_write_time(f1, std::mktime(tmp));
    std::time_t ft2 = fs::last_write_time(f1);
    cout << "  last_write_time() for the file is now "
      << std::asctime(std::gmtime(&ft2)) << endl;
    BOOST_TEST(ft != fs::last_write_time(f1));

    cout << "\n  Reset to current time" << endl;
    fs::last_write_time(f1, ft);
    double time_diff = std::difftime(ft, fs::last_write_time(f1));
    cout 
      << "  original last_write_time() - current last_write_time() is "
      << time_diff << " seconds" << endl;
    BOOST_TEST(time_diff >= -60.0 && time_diff <= 60.0);
  }

  //  platform_specific_tests  ---------------------------------------------------------//