C++如何实现一个简单的日志系统_C++ 日志系统实现方法

enum LogLevel {
    DEBUG,
    INFO,
    WARNING,
    ERROR
};

#include <chrono>
#include <ctime>
#include <iostream>
#include <sstream>

std::string getCurrentTime() {
    auto now = std::chrono::system_clock::now();
    std::time_t time = std::chrono::system_clock::to_time_t(now);
    std::tm tm = *std::localtime(&time);

    std::ostringstream oss;
    oss << std::put_time(&tm, "%Y-%m-%d %H:%M:%S");
    return oss.str();
}

#include <fstream>

void log(LogLevel level, const std::string& message) {
    std::ofstream logfile("app.log", std::ios_base::app); // 追加模式

    std::string levelStr;
    switch (level) {
        case DEBUG:   levelStr = "DEBUG";   break;
        case INFO:    levelStr = "INFO";    break;
        case WARNING: levelStr = "WARNING"; break;
        case ERROR:   levelStr = "ERROR";   break;
    }

    std::string timestamp = getCurrentTime();
    std::string logEntry = "[" + timestamp + "] [" + levelStr + "] " + message + "\n";

    // 输出到控制台
    std::cout << logEntry;

    // 写入文件
    if (logfile.is_open()) {
        logfile << logEntry;
        logfile.close();
    }
}

#define LOG_DEBUG(msg) log(DEBUG, msg)
#define LOG_INFO(msg)  log(INFO, msg)
#define LOG_WARNING(msg) log(WARNING, msg)
#define LOG_ERROR(msg) log(ERROR, msg)

LOG_INFO("程序启动成功");
LOG_WARNING("配置文件未找到，使用默认值");
LOG_ERROR("网络连接失败");