socket-实现简单的聊天

一.Socket的功能图示

二.使用Socket完成简单的聊天功能

1.服务端代码

- (void)viewDidLoad {
    [super viewDidLoad];
    
    //TCP套接字
    int serverSocket = socket(AF_INET, SOCK_STREAM, 0);
    
    //判断套接字的创建状态
    if (serverSocket == -1) {
        NSLog(@"创建socket失败");
    }else{
        NSLog(@"创建socket成功");
    }
    
    //绑定套接字
    struct sockaddr_in addr;
    addr.sin_family = AF_INET; //IP地址类型
    addr.sin_addr.s_addr = inet_addr("127.0.0.1");//IP地址
    addr.sin_port = htons(1234);//端口号
    int result = bind(serverSocket, (const struct sockaddr*)&addr, sizeof(addr));
    
    //判断绑定状态
    if (result == -1) {
        NSLog(@"绑定出错");
    }else{
        NSLog(@"绑定成功");
    }
    
    //被动监听
    result = listen(serverSocket, 5);
    
    //判断监听是否成功
    if (result == -1) {
        NSLog(@"监听失败");
    }else{
        NSLog(@"监听成功");
    }
    
    //保存客户端的信息
    struct sockaddr_in c_addr;
    //保存客户端信息的字节
    socklen_t c_addr_len;
    //接受数据的缓冲区
    char buff[1024];
    
    //死循环持续接受客户端请求
    while (1) {
        
        //获得用于和客户端通信的socket
        int newSocket = accept(serverSocket, (struct sockaddr *)&c_addr, &c_addr_len);
        
        //判断接受客户端请求是否成功
        if (newSocket == -1) {
            
            NSLog(@"接受数据失败");
        }else{
            
            
            //客户端的IP地址为
            NSLog(@"开始聊天了：%s",inet_ntoa(c_addr.sin_addr));
            
            //接受数据
            size_t length = read(newSocket, buff, 1024);
            NSLog(@"接受了%zu字节: %s",length,buff);
            
            //发送数据
            char *message = "Hello World";
            length = write(newSocket, message, strlen(message));
            NSLog(@"成功发送给客户端%zu字节",length);
        }
    }
}

2.客户端代码

- (void)viewDidLoad {
    [super viewDidLoad];
    
    
    //TCP套接字
    int clientSocket = socket(AF_INET, SOCK_STREAM, 0);
    
    //判断套接字是否创建成功
    if (clientSocket == -1) {
        NSLog(@"创建socket失败");
    }else{
        NSLog(@"创建socket成功");
    }
    
    //发起连接
    struct sockaddr_in addr;
    addr.sin_family = AF_INET;//IP地址类型
    addr.sin_addr.s_addr = inet_addr("127.0.0.1");//IP地址
    addr.sin_port = htons(1234);//端口号
    int result = connect(clientSocket, (const struct sockaddr*)&addr, sizeof(addr));
    
    //判断连接是否成功
    if (result == -1) {
        NSLog(@"连接出错");
    }else{
        NSLog(@"连接成功");
    }
    
    //接受数据的缓冲区
    char buff[1024];
    
    //发送数据
    char *message = "Hello World";
    ssize_t length = write(clientSocket, message, strlen(message));
    NSLog(@"成功发送给客户端%zu字节",length);

    //接受数据
    length = read(clientSocket, buff, 1024);
    NSLog(@"接受了%zu字节: %s",length,buff);
    
}

3.运行结果

127.0.0.1的另一种形式是16777343

unsigned long ip = inet_addr("127.0.0.1");
printf("%ld\n", ip);
运行结果：16777343

运行服务端打印结果

2019-05-16 20:44:18.021821+0800 Server-服务端[4345:158908] 创建socket成功
2019-05-16 20:44:18.022118+0800 Server-服务端[4345:158908] 绑定成功
2019-05-16 20:44:18.022296+0800 Server-服务端[4345:158908] 监听成功

运行客户端打印结果

2019-05-16 20:44:34.213811+0800 客户端-Client[4362:159468] 创建socket成功
2019-05-16 20:44:34.214072+0800 客户端-Client[4362:159468] 连接成功
2019-05-16 20:44:34.214346+0800 客户端-Client[4362:159468] 成功发送给客户端11字节
2019-05-16 20:44:34.215025+0800 客户端-Client[4362:159468] 接受了11字节: Hello World

运行客户端之后服务端的打印结果

2019-05-16 20:44:18.021821+0800 Server-服务端[4345:158908] 创建socket成功
2019-05-16 20:44:18.022118+0800 Server-服务端[4345:158908] 绑定成功
2019-05-16 20:44:18.022296+0800 Server-服务端[4345:158908] 监听成功
2019-05-16 20:44:34.214103+0800 Server-服务端[4345:158908] 开始聊天了：16777216
2019-05-16 20:44:34.214593+0800 Server-服务端[4345:158908] 接受了11字节: Hello World��
2019-05-16 20:44:34.214843+0800 Server-服务端[4345:158908] 成功发送给客户端11字节

四.代码链接

工程链接:
https://pan.baidu.com/s/1R7ng8v1RFjkYAJRqS0EoRA
密码:0sj6