类封装socket实现tcp，udp的代码

下面是一个简单的示例代码，用C++封装了Socket类，实现了TCP和UDP协议的通信功能。

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

using namespace std;

class Socket {
public:
    Socket(int type);
    ~Socket();

    int Bind(const string& ip, unsigned short port);
    int Listen(int backlog = 5);
    int Accept(Socket& client);
    int Connect(const string& ip, unsigned short port);
    void Close();

    int Send(const string& data);
    int Recv(string& data);

private:
    int _sockfd;
    int _type;
};

Socket::Socket(int type): _type(type) {
    if (type == SOCK_STREAM) {
        _sockfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    } else if (type == SOCK_DGRAM) {
        _sockfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
    } else {
        _sockfd = -1;
    }
}

Socket::~Socket() {
    Close();
}

int Socket::Bind(const string& ip, unsigned short port) {
    sockaddr_in addr = {};
    addr.sin_family = AF_INET;
    addr.sin_port = htons(port);
    if (ip.empty()) {
        addr.sin_addr.s_addr = INADDR_ANY;
    } else {
        addr.sin_addr.s_addr = inet_addr(ip.c_str());
    }
    return bind(_sockfd, (sockaddr*)&addr, sizeof(addr));
}

int Socket::Listen(int backlog) {
    return listen(_sockfd, backlog);
}

int Socket::Accept(Socket& client) {
    sockaddr_in addr = {};
    socklen_t addrlen = sizeof(addr);
    int sockfd = accept(_sockfd, (sockaddr*)&addr, &addrlen);
    if (sockfd < 0) {
        return sockfd;
    }
    client._sockfd = sockfd;
    client._type = _type;
    return 0;
}

int Socket::Connect(const string& ip, unsigned short port) {
    sockaddr_in addr = {};
    addr.sin_family = AF_INET;
    addr.sin_port = htons(port);
    addr.sin_addr.s_addr = inet_addr(ip.c_str());
    return connect(_sockfd, (sockaddr*)&addr, sizeof(addr));
}

void Socket::Close() {
    if (_sockfd != -1) {
        close(_sockfd);
        _sockfd = -1;
    }
}

int Socket::Send(const string& data) {
    return send(_sockfd, data.c_str(), data.size(), 0);
}

int Socket::Recv(string& data) {
    char buffer[1024] = {};
    int n = recv(_sockfd, buffer, sizeof(buffer), 0);
    if (n > 0) {
        data = string(buffer, n);
    }
    return n;
}

int main() {
    Socket server(SOCK_STREAM);
    server.Bind("127.0.0.1", 8080);
    server.Listen();

    Socket client(SOCK_STREAM);
    client.Connect("127.0.0.1", 8080);

    Socket conn(SOCK_STREAM);
    server.Accept(conn);

    string message = "Hello, world!";
    client.Send(message);
    string buffer;
    conn.Recv(buffer);
    cout << buffer << endl;

    return 0;
}

以上是一个简单的Socket类的实现，可以通过调用Socket类的方法，实现TCP和UDP协议的通信。其中，Bind方法用于绑定IP地址和端口号，Listen方法用于监听连接请求，Accept方法用于接受客户端连接，Connect方法用于连接到服务端，Send方法用于发送数据，Recv方法用于接收数据。