CMake

cmake_minimum_required(VERSION 3.11)
project(spdlog_example)

if(NOT TARGET spdlog)
    find_package(spdlog REQUIRED)
endif()

add_executable(${PROJECT_NAME} spdlog_example.cc)
target_link_libraries(${PROJECT_NAME} PRIVATE spdlog::spdlog $<$<BOOL:${MINGW}>:ws2_32>)

日志等级

namespace level {
enum level_enum : int {
    trace = SPDLOG_LEVEL_TRACE,
    debug = SPDLOG_LEVEL_DEBUG,
    info = SPDLOG_LEVEL_INFO,
    warn = SPDLOG_LEVEL_WARN,
    err = SPDLOG_LEVEL_ERROR,
    critical = SPDLOG_LEVEL_CRITICAL,
    off = SPDLOG_LEVEL_OFF,
    n_levels
};

1. 简单输出日志

void load_levels_example() {
    spdlog::cfg::load_env_levels();
}

int main(int , char* []) {

    load_levels_example();
    spdlog::info("This is spdlog version {}.{}.{}!", SPDLOG_VER_MAJOR, SPDLOG_VER_MINOR, SPDLOG_VER_PATCH);
    spdlog::warn("Easy padding in numbers like {:08d}", 12);
    spdlog::critical("Support for int: {0:d}, hex: {0:x}; oct: {0:o}; bin: {0:b}", 42);
    spdlog::info("Support for floats {:03.2f}", 1.23456);
    spdlog::info("Positional args are {1} {0}..", "too", "supported");
    spdlog::info("{:>8} aligned, {:<8} aligned", "right", "left");
}

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2. 输出指定等级之上的日志

int main(int , char* []) {

    spdlog::set_level(spdlog::level::info);
    spdlog::debug("This message should be dispalyed!");
    spdlog::set_level(spdlog::level::trace);
    spdlog::debug("This message should be displayed..");
}

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3. 设置样式

int main(int, char* []) {

    spdlog::set_pattern("[%H:%M:%S %z] [%^%L%$] [thread %t] %v");
    spdlog::info("This an info message with custom format");
    spdlog::set_pattern("%+");
    spdlog::set_level(spdlog::level::info);
    spdlog::enable_backtrace(10);
    for (int i = 0; i < 100; i++) {
        spdlog::debug("Backtrace message {}", i);
    }
    spdlog::dump_backtrace();
}

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在终端（控制台输出）

int main() {

    auto logger = spdlog::stdout_color_mt<spdlog::async_factory>("console logger");
    logger->set_level(spdlog::level::info);
    logger->info("console info log");
    spdlog::get("console logger")->critical("console debug log");

    // auto formatter = std::make_unique<spdlog::pattern_formatter>();
    // formatter->set_pattern("[%n] [%*] [%^%l%$] %v");
    // formatter->add_flag
    // logger->set_formatter(std::move(formatter));
    logger->warn("format warn log");
    return 0;
}

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自定义格式

class my_formatter_flag : public spdlog::custom_flag_formatter
{
public:
    void format(const spdlog::details::log_msg &, const std::tm &, spdlog::memory_buf_t &dest) override
    {
        std::string some_txt = "mark-flag";
        dest.append(some_txt.data(), some_txt.data() + some_txt.size());
    }
    std::unique_ptr<custom_flag_formatter> clone() const override
    {
        return spdlog::details::make_unique<my_formatter_flag>();
    }
};

int main() {

    spdlog::info("hello world");

    auto logger = spdlog::stdout_color_mt<spdlog::async_factory>("console");
    logger->info("hello world too!!");
    spdlog::get("console")->info("hello world too too !!!");

    auto sink1 = std::make_shared<spdlog::sinks::stdout_color_sink_mt>();
    auto sink2 = std::make_shared<spdlog::sinks::basic_file_sink_mt>("mark.txt");


    auto formatter = std::make_unique<spdlog::pattern_formatter>();
    formatter->add_flag<my_formatter_flag>('*').set_pattern("[%D] [%n] [%*] %v");
    sink1->set_formatter(std::move(formatter));

    sink2->set_pattern("[%^%l%$] %v");

    auto logger1 = std::make_shared<spdlog::logger>(std::string("console1"));

    logger1->sinks().push_back(sink1);
    logger1->sinks().push_back(sink2);
    spdlog::register_logger(logger1);
}

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写到文件

int main() {

spdlog::info("hello world");

auto logger = spdlog::stdout_color_mt<spdlog::async_factory>("console");
logger->info("hello world too!!");
spdlog::get("console")->info("hello world too too !!!");

auto sink1 = std::make_shared<spdlog::sinks::stdout_color_sink_mt>();
auto sink2 = std::make_shared<spdlog::sinks::basic_file_sink_mt>("mark.txt");


auto formatter = std::make_unique<spdlog::pattern_formatter>();
formatter->add_flag<my_formatter_flag>('*').set_pattern("[%D] [%n] [%*] %v");
sink1->set_formatter(std::move(formatter));

sink2->set_pattern("[%^%l%$] %v");

auto logger1 = std::make_shared<spdlog::logger>(std::string("console1"));

logger1->sinks().push_back(sink1);
logger1->sinks().push_back(sink2);
spdlog::register_logger(logger1);

spdlog::get("console1")->info("hello world too too too!!!!");

SPDLOG_INFO("hello mark too!");
SPDLOG_LOGGER_INFO(spdlog::get("console1"), "hello mark too too !!!");
}

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