Parse the UTF8 ".ini" file via the Boost property_tree #devsample #boost

0-read-ini.cpp

/**
 * Parse the UTF8 ".ini" file via the Boost property_tree
 */

#include <string>
#include <fstream>

#if defined(__APPLE__)
#   include <codecvt>
#endif /* defined(__APPLE__) */

#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/ini_parser.hpp>
#include <boost/program_options/detail/convert.hpp>
#include <boost/program_options/detail/utf8_codecvt_facet.hpp>
#include <boost/program_options.hpp>

/* namespace alias */
namespace po = boost::program_options;
namespace pt = boost::property_tree;

static void read_ini_file(const char *filename, const char *locale)
{
    /* udpate locale */
    setlocale(LC_ALL, locale);

    /* Open the UTF8 .ini file */
    std::locale oldLocale;
    std::locale utf8Locale(oldLocale, new po::detail::utf8_codecvt_facet());
    std::wifstream iniStream(filename);
    iniStream.imbue(utf8Locale);

    /* Parse the .ini file via boost::property_tree::ini_parser */
    pt::wptree iniWPTree;
    pt::ini_parser::read_ini(iniStream, iniWPTree);

    /* Test INI File:
     * [app]
     * string=test string
     * number=99
     */

    /* Read the string */
    boost::optional<std::wstring> strVal = 
        iniWPTree.get_optional<std::wstring>(L"app.string");
    std::wstring ret = strVal.get_value_or(std::wstring(L"defaultStrVal"));

#if defined(__APPLE__)
    /* coodecvt for OSX terminate */
    std::wstring_convert<std::codecvt_utf8<wchar_t>,wchar_t> convert;
    std::cout << "app.string=" << convert.to_bytes(ret) << std::endl;
#else
    /* NOTE: must update the correct locale setting 
     *       before you print the string 
     * For instance: 
     *      Chinese  -> "zh-CN"
     *      EN-US    -> "en-US.UTF8"
     */
    wprintf(L"app.string=%s\n", ret.c_str());
#endif /* defined(__APPLE__) */

    /* Read the number */
    boost::optional<uint32_t> numVal = 
        iniWPTree.get_optional<uint32_t>(L"app.number");
    const uint32_t numValDefault = 100;
    std::cout << "app.number="
        << numVal.get_value_or(numValDefault)
        << std::endl;
}

int main(int argc, char **argv)
{
    po::options_description desc("MainOptions");
    desc.add_options()
        ("help,h", "Print help message")
        ("locale,l",
            po::value<std::string>()->default_value("C"),
            "Locale settings (e.g. en-US.UTF8, zh-CN) ")
        ("file,f", 
            po::value<std::string>()->default_value("test.ini"),
            "The test .ini file");

    po::variables_map vm;
    try
    {
        po::store(po::parse_command_line(argc, argv, desc), vm);
    }
    catch (po::error &e)
    {
        /* Invalid options */
        std::cerr << "ERROR: " << e.what() << std::endl << std::endl;
        std::cout << "Boost property_tree tester:" << std::endl
            << desc << std::endl;
        return 0;
    }

    if (vm.count("help"))
    {
        /* print usage */
        std::cout << "Boost property_tree tester:" << std::endl
                  << desc << std::endl;
        return 0;
    }

    std::string iniFile = vm["file"].as<std::string>().c_str();
    std::cout << "Read ini file: " << iniFile << std::endl;
    read_ini_file(iniFile.c_str(), vm["locale"].as<std::string>().c_str());
    return 0;
}

CMakeLists.txt

# CMake build script (read .ini) 
cmake_minimum_required(VERSION 2.8)

# project name & version
project(ReadIni)

# common settings (Boost libraries)
if (MSVC)
    # Enable the static libraries on Windows
    foreach (flag_var 
        CMAKE_CXX_FLAGS CMAKE_CXX_FLAGS_DEBUG CMAKE_CXX_FLAGS_RELEASE
        CMAKE_CXX_FLAGS_MINSIZEREL CMAKE_CXX_FLAGS_RELWITHDEBINFO
        CMAKE_C_FLAGS CMAKE_C_FLAGS_DEBUG CMAKE_C_FLAGS_RELEASE
        CMAKE_C_FLAGS_MINSIZEREL CMAKE_C_FLAGS_RELWITHDEBINFO)
        # update to the static version of the run time library
        string(REPLACE "/MD" "/MT" ${flag_var} "${${flag_var}}")
    endforeach()

    unset(Boost_LIBRARIES)
    set(Boost_USE_STATIC ON)
    set(Boost_USE_STATIC_LIBS ON)
    set(Boost_USE_MULTITHREADED ON)
    set(Boost_USE_STATIC_RUNTIME ON)
endif()

find_package(Boost REQUIRED COMPONENTS 
    program_options)

include_directories("${PROJECT_SOURCE_DIR}"
    "${Boost_INCLUDE_DIRS}")

set(rdcfg_boost_dbg_libs 
    "${Boost_PROGRAM_OPTIONS_LIBRARY_DEBUG}")
set(rdcfg_boost_opt_libs 
    "${Boost_PROGRAM_OPTIONS_LIBRARY_RELEASE}")

# application
add_executable(read-ini 
    "${PROJECT_SOURCE_DIR}/0-read-ini.cpp")

target_link_libraries(read-ini
    debug "${rdcfg_boost_dbg_libs}"
    optimized "${rdcfg_boost_opt_libs}")

# install
install(TARGETS read-ini DESTINATION bin)