Log file is not getting created

问题

I need a global logger that I can use across multiple classes in my project. I want to have logger settings in an ini file.

I start following example here and combined it with some suggestions at my earlier question here.

My Logger.h is as follows.

#pragma once

#include <boost/log/common.hpp>
#include <boost/log/attributes.hpp>
#include <boost/log/utility/setup/from_stream.hpp>
#include <boost/regex.hpp>

#include <boost/log/expressions.hpp>
#include <boost/log/sources/global_logger_storage.hpp>
#include <boost/log/support/date_time.hpp>
#include <boost/log/trivial.hpp>
#include <boost/log/utility/setup.hpp>


#define INFO  BOOST_LOG_SEV(my_logger::get(), boost::log::trivial::info)
#define WARN  BOOST_LOG_SEV(my_logger::get(), boost::log::trivial::warning)
#define ERROR BOOST_LOG_SEV(my_logger::get(), boost::log::trivial::error)

//Narrow-char thread-safe logger.
typedef boost::log::sources::severity_logger_mt<boost::log::trivial::severity_level> logger_t;

//declares a global logger with a custom initialization
BOOST_LOG_GLOBAL_LOGGER(my_logger, logger_t)
BOOST_LOG_INLINE_GLOBAL_LOGGER_DEFAULT(test_lg, boost::log::sources::severity_logger< >)

The Logger.cpp is as follows.

#include "stdafx.h"
#include "Logger.h"
#include <fstream>

namespace attrs = boost::log::attributes;
namespace expr = boost::log::expressions;
namespace logging = boost::log;

//Defines a global logger initialization routine
BOOST_LOG_GLOBAL_LOGGER_INIT(my_logger, logger_t)
{
    logger_t lg;

    logging::add_common_attributes();

    std::ifstream settings("settings.ini");
    if (!settings.is_open())
    {
        std::cout << "Could not open settings.txt file" << std::endl;
        //return 1;
    }

    // Read the settings and initialize logging library
    logging::init_from_stream(settings);

    // Add some attributes
    logging::core::get()->add_global_attribute("TimeStamp", attrs::local_clock());
    logging::register_simple_filter_factory<logging::trivial::severity_level>("Severity");

    return lg;
}

The settings.ini looks like below

#
#          Copyright Andrey Semashev 2007 - 2014.
# Distributed under the Boost Software License, Version 1.0.
#    (See accompanying file LICENSE_1_0.txt or copy at
#          http://www.boost.org/LICENSE_1_0.txt)
#

[Core]
Filter="%Severity% >= debug"

[Sinks.1]
Destination=TextFile
FileName=test.log
AutoFlush=true
Format="[%TimeStamp%] <%Severity%> (%Channel%): %Message%"

Finally I am trying to use logger as below.

#include "Logger.h"
int wmain(int argc, wchar_t* argv[])
{
    INFO << "Program started";
}

However, no log file is getting created. What am I doing wrong now?

回答1:

The filter factory needs to be registered before parsing the settings ini.

// Add some attributes
logging::core::get()->add_global_attribute("TimeStamp", attrs::local_clock());
logging::register_simple_filter_factory<logging::trivial::severity_level>("Severity");

Needs to be in front of the call

// Read the settings and initialize logging library
logging::init_from_stream(settings);

Without the factory, the filter is not interpreted and ends up filtering everything.

来源：https://stackoverflow.com/questions/52172457/log-file-is-not-getting-created

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c++

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boost-log

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