Socket库在C++中的日志记录

在C++中，使用Socket库进行日志记录时，通常需要将日志消息发送到远程服务器或本地文件。为了实现这一功能，我们可以使用C++的Socket编程技巧来创建一个简单的日志记录客户端或服务端。

以下是一个简单的C++ Socket日志记录客户端示例：

#include <iostream>
#include <string>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>

#define SERVER_IP "127.0.0.1"
#define SERVER_PORT 12345
#define BUFFER_SIZE 1024

void logMessage(const std::string& message) {
    int sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock == -1) {
        std::cerr << "Error creating socket" << std::endl;
        return;
    }

    struct sockaddr_in serverAddr;
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_port = htons(SERVER_PORT);
    serverAddr.sin_addr.s_addr = inet_addr(SERVER_IP);

    if (connect(sock, (struct sockaddr *)&serverAddr, sizeof(serverAddr)) == -1) {
        std::cerr << "Error connecting to server" << std::endl;
        close(sock);
        return;
    }

    send(sock, message.c_str(), message.size(), 0);
    close(sock);
}

int main() {
    std::string logMessage = "This is a test log message";
    logMessage += "\n";
    logMessage += "------------------------------------\n";

    logMessage(logMessage);

    return 0;
}

以下是一个简单的C++ Socket日志记录服务端示例：

#include <iostream>
#include <string>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <fstream>

#define SERVER_IP "127.0.0.1"
#define SERVER_PORT 12345
#define BUFFER_SIZE 1024

void logMessage(const std::string& message) {
    std::ofstream logFile("log.txt", std::ios::app);
    if (!logFile.is_open()) {
        std::cerr << "Error opening log file" << std::endl;
        return;
    }

    logFile << message;
    logFile.close();
}

int main() {
    int serverSocket = socket(AF_INET, SOCK_STREAM, 0);
    if (serverSocket == -1) {
        std::cerr << "Error creating socket" << std::endl;
        return 1;
    }

    struct sockaddr_in serverAddr;
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_port = htons(SERVER_PORT);
    serverAddr.sin_addr.s_addr = INADDR_ANY;

    if (bind(serverSocket, (struct sockaddr *)&serverAddr, sizeof(serverAddr)) == -1) {
        std::cerr << "Error binding socket" << std::endl;
        close(serverSocket);
        return 1;
    }

    if (listen(serverSocket, 5) == -1) {
        std::cerr << "Error listening on socket" << std::endl;
        close(serverSocket);
        return 1;
    }

    struct sockaddr_in clientAddr;
    socklen_t clientAddrSize = sizeof(clientAddr);

    int clientSocket = accept(serverSocket, (struct sockaddr *)&clientAddr, &clientAddrSize);
    if (clientSocket == -1) {
        std::cerr << "Error accepting client connection" << std::endl;
        close(serverSocket);
        return 1;
    }

    char buffer[BUFFER_SIZE];
    while (true) {
        ssize_t bytesReceived = recv(clientSocket, buffer, BUFFER_SIZE - 1, 0);
        if (bytesReceived == -1) {
            std::cerr << "Error receiving data from client" << std::endl;
            break;
        } else if (bytesReceived == 0) {
            std::cerr << "Client disconnected" << std::endl;
            break;
        }

        buffer[bytesReceived] = '\0';
        logMessage(buffer);
    }

    close(clientSocket);
    close(serverSocket);

    return 0;
}

在这个示例中，我们创建了一个简单的日志记录服务端，它监听指定的端口并接收客户端发送的日志消息。接收到的日志消息将被追加到名为log.txt的文件中。同时，我们还提供了一个简单的日志记录客户端，用于将日志消息发送到服务端。

请注意，这个示例仅用于演示目的，实际应用中可能需要考虑更多的错误处理和功能。