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用C语言在Linux中使用TCP协议发送文本消息

1.用C语言在Linux中使用TCP协议发送一句文本消息

1.使用C语言在Linux中创建服务端程序接收一句文本消息

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// LinServer.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h> // for close()
#include <arpa/inet.h> // for sockaddr_in, inet_ntop
#include <sys/socket.h> // for socket(), bind(), listen(), accept()

int main() {
    int serverSocket, clientSocket;
    struct sockaddr_in server, client;
    socklen_t clientSize;
    char buffer[1024];
    int recvSize;

    // 创建 socket
    serverSocket = socket(AF_INET, SOCK_STREAM, 0);
    if (serverSocket < 0) {
        perror("Could not create socket");
        return 1;
    }

    // 设置服务器信息
    server.sin_family = AF_INET;
    server.sin_addr.s_addr = INADDR_ANY; // 监听所有可用的接口
    server.sin_port = htons(8888); // 服务器端口

    // 绑定 socket
    if (bind(serverSocket, (struct sockaddr*)&server, sizeof(server)) < 0) {
        perror("Bind failed");
        close(serverSocket);
        return 1;
    }

    // 开始监听
    if (listen(serverSocket, 3) < 0) {
        perror("Listen failed");
        close(serverSocket);
        return 1;
    }
    printf("Waiting for incoming connections...\n");

    clientSize = sizeof(client);
    // 接受连接
    clientSocket = accept(serverSocket, (struct sockaddr*)&client, &clientSize);
    if (clientSocket < 0) {
        perror("Accept failed");
        close(serverSocket);
        return 1;
    }

    char clientIP[INET_ADDRSTRLEN]; // 用于存储客户端 IP 地址
    inet_ntop(AF_INET, &client.sin_addr, clientIP, sizeof(clientIP)); // 使用 inet_ntop
    printf("Connection accepted from %s:%d\n", clientIP, ntohs(client.sin_port));

    // 接收消息
    while ((recvSize = recv(clientSocket, buffer, sizeof(buffer) - 1, 0)) > 0) {
        buffer[recvSize] = '\0'; // 添加字符串结束符
        printf("Received message: %s\n", buffer);
    }

    if (recvSize < 0) {
        perror("Receive failed");
    }

    // 关闭 sockets
    close(clientSocket);
    close(serverSocket);
    return 0;
}

2.使用C语言在Linux中创建客户端程序发送一句文本消息

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// LinClient.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h> // for close()
#include <arpa/inet.h> // for sockaddr_in, inet_pton
#include <sys/socket.h> // for socket(), connect()

int main() {
    int sock;
    struct sockaddr_in server;
    char* message;
    int sendResult;

    // 创建 socket
    sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock < 0) {
        perror("Could not create socket");
        return 1;
    }

    // 设置服务器信息
    server.sin_family = AF_INET;
    server.sin_port = htons(8888); // 服务器端口

    // 使用 inet_pton 将 IP 地址转换为网络字节顺序
    if (inet_pton(AF_INET, "127.0.0.1", &server.sin_addr) <= 0) {
        perror("Invalid address/ Address not supported");
        close(sock);
        return 1;
    }

    // 连接到服务器
    if (connect(sock, (struct sockaddr*)&server, sizeof(server)) < 0) {
        perror("Connection failed");
        close(sock);
        return 1;
    }

    // 要发送的消息
    message = "Hello, Server!";

    // 发送消息
    sendResult = send(sock, message, strlen(message), 0);
    if (sendResult < 0) {
        perror("Send failed");
    } else {
        printf("Message sent: %s\n", message);
    }

    // 关闭 socket
    close(sock);
    return 0;
}

3.运行结果

  1. 运行LinServer
  2. 运行LinClient
  3. 运行成功

2.用C语言在Linux中使用TCP协议多次发送文本消息

1.使用C语言在Linux中创建服务端程序多次接收文本消息

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// LinServer.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h> // for close()
#include <arpa/inet.h> // for sockaddr_in, inet_ntop
#include <sys/socket.h> // for socket(), bind(), listen(), accept()

int main() {
    int serverSocket, clientSocket;
    struct sockaddr_in server, client;
    socklen_t clientSize;
    char buffer[1024];
    int recvSize;

    // 创建 socket
    serverSocket = socket(AF_INET, SOCK_STREAM, 0);
    if (serverSocket < 0) {
        perror("Could not create socket");
        return 1;
    }

    // 设置服务器信息
    server.sin_family = AF_INET;
    server.sin_addr.s_addr = INADDR_ANY; // 监听所有可用的接口
    server.sin_port = htons(8888); // 服务器端口

    // 绑定 socket
    if (bind(serverSocket, (struct sockaddr*)&server, sizeof(server)) < 0) {
        perror("Bind failed");
        close(serverSocket);
        return 1;
    }

    // 开始监听
    if (listen(serverSocket, 3) < 0) {
        perror("Listen failed");
        close(serverSocket);
        return 1;
    }
    printf("Waiting for incoming connections...\n");

    clientSize = sizeof(client);
    // 接受连接
    clientSocket = accept(serverSocket, (struct sockaddr*)&client, &clientSize);
    if (clientSocket < 0) {
        perror("Accept failed");
        close(serverSocket);
        return 1;
    }

    char clientIP[INET_ADDRSTRLEN]; // 用于存储客户端 IP 地址
    inet_ntop(AF_INET, &client.sin_addr, clientIP, sizeof(clientIP)); // 使用 inet_ntop
    printf("Connection accepted from %s:%d\n", clientIP, ntohs(client.sin_port));

    // 接收消息
    while ((recvSize = recv(clientSocket, buffer, sizeof(buffer) - 1, 0)) > 0) {
        buffer[recvSize] = '\0'; // 添加字符串结束符
        printf("Received message: %s\n", buffer);
    }

    if (recvSize < 0) {
        perror("Receive failed");
    }

    // 关闭 sockets
    close(clientSocket);
    close(serverSocket);
    return 0;
}

2.使用C语言在Linux中创建客户端程序多次发送文本消息

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// LinClient.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h> // for close()
#include <arpa/inet.h> // for sockaddr_in, inet_pton
#include <sys/socket.h> // for socket(), connect()

int main() {
    int sock;
    struct sockaddr_in server;
    char message[1024];
    int sendResult;

    // 创建 socket
    sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock < 0) {
        perror("Could not create socket");
        return 1;
    }

    // 设置服务器信息
    server.sin_family = AF_INET;
    server.sin_port = htons(8888); // 服务器端口

    // 使用 inet_pton 将 IP 地址转换为网络字节顺序
    if (inet_pton(AF_INET, "127.0.0.1", &server.sin_addr) <= 0) {
        perror("Invalid address/ Address not supported");
        close(sock);
        return 1;
    }

    // 连接到服务器
    if (connect(sock, (struct sockaddr*)&server, sizeof(server)) < 0) {
        perror("Connection failed");
        close(sock);
        return 1;
    }

    // 发送多条消息
    while (1) {
        printf("Enter message (type 'exit' to quit): ");
        fgets(message, sizeof(message), stdin);
        message[strcspn(message, "\n")] = 0; // 去掉换行符

        // 检查是否退出
        if (strcmp(message, "exit") == 0) {
            break;
        }

        // 发送消息
        sendResult = send(sock, message, strlen(message), 0);
        if (sendResult < 0) {
            perror("Send failed");
            break;
        } else {
            printf("Message sent: %s\n", message);
        }
    }

    // 关闭 socket
    close(sock);
    return 0;
}

3.运行结果

  1. 运行LinServer

  2. 运行LinClient

  3. 运行成功

3.用C语言在Linux中使用TCP协议客户端退出后可以再次连接服务器

1.使用C语言在Linux中创建服务端程序断开后等待客户端连接

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// LinServer.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h> // for close()
#include <arpa/inet.h> // for sockaddr_in, inet_ntop
#include <sys/socket.h> // for socket(), bind(), listen(), accept()

int main() {
    int serverSocket, clientSocket;
    struct sockaddr_in server, client;
    socklen_t clientSize;
    char buffer[1024];
    int recvSize;

    // 创建 socket
    serverSocket = socket(AF_INET, SOCK_STREAM, 0);
    if (serverSocket < 0) {
        perror("Could not create socket");
        return 1;
    }

     // 设置 SO_REUSEADDR 选项
     int opt = 1;
     if (setsockopt(serverSocket, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0) {
         perror("setsockopt failed");
         close(serverSocket);
         exit(EXIT_FAILURE);
     }
 
    // 设置服务器信息
    server.sin_family = AF_INET;
    server.sin_addr.s_addr = INADDR_ANY; // 监听所有可用的接口
    server.sin_port = htons(8888); // 服务器端口

    // 绑定 socket
    if (bind(serverSocket, (struct sockaddr*)&server, sizeof(server)) < 0) {
        perror("Bind failed");
        close(serverSocket);
        return 1;
    }

    // 开始监听
    if (listen(serverSocket, 3) < 0) {
        perror("Listen failed");
        close(serverSocket);
        return 1;
    }
    printf("Waiting for incoming connections...\n");

    clientSize = sizeof(client);

    // 循环接受连接
    while (1) {
        // 接受连接
        clientSocket = accept(serverSocket, (struct sockaddr*)&client, &clientSize);
        if (clientSocket < 0) {
            perror("Accept failed");
            close(serverSocket);
            return 1;
        }

        char clientIP[INET_ADDRSTRLEN]; // 用于存储客户端 IP 地址
        inet_ntop(AF_INET, &client.sin_addr, clientIP, sizeof(clientIP)); // 使用 inet_ntop
        printf("Connection accepted from %s:%d\n", clientIP, ntohs(client.sin_port));

        // 接收消息
        while ((recvSize = recv(clientSocket, buffer, sizeof(buffer) - 1, 0)) > 0) {
            buffer[recvSize] = '\0'; // 添加字符串结束符
            printf("Received message: %s\n", buffer);
        }

        if (recvSize < 0) {
            perror("Receive failed");
        }

        // 关闭客户端 socket
        close(clientSocket);
        printf("Client disconnected.\n");
    }

    // 关闭服务器 socket
    close(serverSocket);
    return 0;
}

2.使用C语言在Linux中创建客户端程序退出后再次连接服务端

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// LinClient.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h> // for close()
#include <arpa/inet.h> // for sockaddr_in, inet_pton
#include <sys/socket.h> // for socket(), connect()

int main() {
    int sock;
    struct sockaddr_in server;
    char message[1024];
    int sendResult;

    // 创建 socket
    sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock < 0) {
        perror("Could not create socket");
        return 1;
    }

    // 设置服务器信息
    server.sin_family = AF_INET;
    server.sin_port = htons(8888); // 服务器端口

    // 使用 inet_pton 将 IP 地址转换为网络字节顺序
    if (inet_pton(AF_INET, "127.0.0.1", &server.sin_addr) <= 0) {
        perror("Invalid address/ Address not supported");
        close(sock);
        return 1;
    }

    // 连接到服务器
    if (connect(sock, (struct sockaddr*)&server, sizeof(server)) < 0) {
        perror("Connection failed");
        close(sock);
        return 1;
    }

    // 发送多条消息
    while (1) {
        printf("Enter message (type 'exit' to quit): ");
        fgets(message, sizeof(message), stdin);
        message[strcspn(message, "\n")] = 0; // 去掉换行符

        // 检查是否退出
        if (strcmp(message, "exit") == 0) {
            break;
        }

        // 发送消息
        sendResult = send(sock, message, strlen(message), 0);
        if (sendResult < 0) {
            perror("Send failed");
            break;
        } else {
            printf("Message sent: %s\n", message);
        }
    }

    // 关闭 socket
    close(sock);
    return 0;
}

3.运行结果

  1. 运行LinServer

  2. 运行LinClient

  3. 运行成功

4.用C语言在Linux中使用TCP协议让客户端与服务端相互发送文本消息

1.使用C语言在Linux中创建服务端接收文本消息后再发送到客户端

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// LinServer.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h> // for close()
#include <arpa/inet.h> // for sockaddr_in, inet_ntop
#include <sys/socket.h> // for socket(), bind(), listen(), accept()

int main() {
    int serverSocket, clientSocket;
    struct sockaddr_in server, client;
    socklen_t clientSize;
    char buffer[1024];
    int recvSize;

    // 创建 socket
    serverSocket = socket(AF_INET, SOCK_STREAM, 0);
    if (serverSocket < 0) {
        perror("Could not create socket");
        return 1;
    }

    // 设置服务器信息
    server.sin_family = AF_INET;
    server.sin_addr.s_addr = INADDR_ANY; // 监听所有可用的接口
    server.sin_port = htons(8888); // 服务器端口

    // 绑定 socket
    if (bind(serverSocket, (struct sockaddr*)&server, sizeof(server)) < 0) {
        perror("Bind failed");
        close(serverSocket);
        return 1;
    }

    // 开始监听
    if (listen(serverSocket, 3) < 0) {
        perror("Listen failed");
        close(serverSocket);
        return 1;
    }
    printf("Waiting for incoming connections...\n");

    clientSize = sizeof(client);

    // 循环接受连接
    while (1) {
        // 接受连接
        clientSocket = accept(serverSocket, (struct sockaddr*)&client, &clientSize);
        if (clientSocket < 0) {
            perror("Accept failed");
            close(serverSocket);
            return 1;
        }

        char clientIP[INET_ADDRSTRLEN]; // 用于存储客户端 IP 地址
        inet_ntop(AF_INET, &client.sin_addr, clientIP, sizeof(clientIP)); // 使用 inet_ntop
        printf("Connection accepted from %s:%d\n", clientIP, ntohs(client.sin_port));

        // 接收和发送消息
        while (1) {
            // 接收消息
            recvSize = recv(clientSocket, buffer, sizeof(buffer) - 1, 0);
            if (recvSize > 0) {
                buffer[recvSize] = '\0'; // 添加字符串结束符
                printf("Received message from client: %s\n", buffer);

                // 发送回客户端
                send(clientSocket, buffer, recvSize, 0);
            }
            else if (recvSize == 0) {
                printf("Client disconnected.\n");
                break; // 客户端断开连接
            }
            else {
                perror("Receive failed");
                break;
            }
        }

        // 关闭客户端 socket
        close(clientSocket);
    }

    // 关闭服务器 socket
    close(serverSocket);
    return 0;
}

2.使用C语言在Linux中创建客户端程序接收与发送文本消息

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// LinClient.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h> // for close()
#include <arpa/inet.h> // for sockaddr_in, inet_pton
#include <sys/socket.h> // for socket(), connect()

int main() {
    int sock;
    struct sockaddr_in server;
    char message[1024];
    char buffer[1024];
    int sendResult, recvSize;

    // 创建 socket
    sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock < 0) {
        perror("Could not create socket");
        return 1;
    }

    // 设置服务器信息
    server.sin_family = AF_INET;
    server.sin_port = htons(8888); // 服务器端口

    // 使用 inet_pton 将 IP 地址转换为网络字节顺序
    if (inet_pton(AF_INET, "127.0.0.1", &server.sin_addr) <= 0) {
        perror("Invalid address/ Address not supported");
        close(sock);
        return 1;
    }

    // 连接到服务器
    if (connect(sock, (struct sockaddr*)&server, sizeof(server)) < 0) {
        perror("Connection failed");
        close(sock);
        return 1;
    }

    // 发送和接收消息
    while (1) {
        printf("Enter message (type 'exit' to quit): ");
        fgets(message, sizeof(message), stdin);
        message[strcspn(message, "\n")] = 0; // 去掉换行符

        // 检查是否退出
        if (strcmp(message, "exit") == 0) {
            break;
        }

        // 发送消息
        sendResult = send(sock, message, strlen(message), 0);
        if (sendResult < 0) {
            perror("Send failed");
            break;
        } else {
            printf("Message sent: %s\n", message);
        }

        // 接收来自服务器的消息
        recvSize = recv(sock, buffer, sizeof(buffer) - 1, 0);
        if (recvSize > 0) {
            buffer[recvSize] = '\0'; // 添加字符串结束符
            printf("Received from server: %s\n", buffer);
        } else if (recvSize == 0) {
            printf("Server disconnected.\n");
            break; // 服务器断开连接
        } else {
            perror("Receive failed");
            break;
        }
    }

    // 关闭 socket
    close(sock);
    return 0;
}

3.运行结果

  1. 运行LinServer

  2. 运行LinClient

  3. 运行成功

5.用C语言在Linux中使用TCP协议让两个客户端之间可以相互发送文本消息

1.使用C语言在Linux中创建服务端接收与转发文本消息到所有客户端中

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// LinServer.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h> // for close()
#include <arpa/inet.h> // for sockaddr_in, inet_ntop
#include <pthread.h> // for pthreads
#include <errno.h>

#define MAX_CLNT 256
#define BUF_SIZE 100

void error_handling(const char* msg);
void* ThreadProc(void* arg);
void send_msg(char* msg, int len);
int clnt_cnt = 0;
int clnt_socks[MAX_CLNT];
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

int main() {
    int serv_sock;
    struct sockaddr_in sin;

    // 创建套接字
    serv_sock = socket(AF_INET, SOCK_STREAM, 0);
    if (serv_sock < 0)
        error_handling("Failed socket()");

    // 设置服务器地址结构
    sin.sin_family = AF_INET;
    sin.sin_port = htons(8888); // 监听端口 8888
    sin.sin_addr.s_addr = INADDR_ANY; // 监听所有可用的接口

    // 绑定套接字
    if (bind(serv_sock, (struct sockaddr*)&sin, sizeof(sin)) < 0)
        error_handling("Failed bind()");

    // 开始监听
    if (listen(serv_sock, 256) < 0)
        error_handling("Failed listen()");
    printf("Start listen:\n");

    struct sockaddr_in remoteAddr;
    socklen_t addrLen = sizeof(remoteAddr);
    pthread_t tid;

    while (1) {
        printf("Waiting for new connection...\n");
        int clnt_sock = accept(serv_sock, (struct sockaddr*)&remoteAddr, &addrLen);
        if (clnt_sock < 0) {
            perror("Failed accept()");
            continue;
        }

        // 添加客户端套接字到数组
        pthread_mutex_lock(&mutex);
        clnt_socks[clnt_cnt++] = clnt_sock;
        pthread_mutex_unlock(&mutex);

        char ip_str[INET_ADDRSTRLEN]; // 用于存储 IP 地址字符串
        inet_ntop(AF_INET, &remoteAddr.sin_addr, ip_str, sizeof(ip_str));
        printf("Connection accepted: %s\n", ip_str);

        // 创建线程处理客户端
        pthread_create(&tid, NULL, ThreadProc, (void*)&clnt_sock);
        pthread_detach(tid); // 使线程在结束时自动释放资源
    }

    close(serv_sock);
    return 0;
}

void error_handling(const char* msg) {
    perror(msg);
    exit(1);
}

void* ThreadProc(void* arg) {
    int clnt_sock = *((int*)arg);
    int str_len = 0;
    char msg[BUF_SIZE];

    // 接收消息并广播
    while ((str_len = recv(clnt_sock, msg, sizeof(msg), 0)) > 0) {
        send_msg(msg, str_len);
        printf("Broadcast message sent\n");
    }

    printf("Client disconnected: %d\n", clnt_sock);
    pthread_mutex_lock(&mutex);
    // 从客户端数组中移除断开的客户端
    for (int i = 0; i < clnt_cnt; i++) {
        if (clnt_sock == clnt_socks[i]) {
            while (i < clnt_cnt - 1) {
                clnt_socks[i] = clnt_socks[i + 1];
                i++;
            }
            break;
        }
    }
    clnt_cnt--;
    pthread_mutex_unlock(&mutex);
    close(clnt_sock);
    return NULL;
}

void send_msg(char* msg, int len) {
    pthread_mutex_lock(&mutex);
    // 向所有客户端发送消息
    for (int i = 0; i < clnt_cnt; i++) {
        send(clnt_socks[i], msg, len, 0);
    }
    pthread_mutex_unlock(&mutex);
}

2.使用C语言在Linux中创建客户端程序接收与发送文本消息

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// LinClient.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h> // for close()
#include <arpa/inet.h> // for sockaddr_in, inet_pton
#include <pthread.h> // for pthreads
#include <errno.h>

#define BUF_SIZE 256
#define NAME_SIZE 30

void* send_msg(void* arg);
void* recv_msg(void* arg);
void error_handling(const char* msg);

char name[NAME_SIZE] = "[DEFAULT]";
char msg[BUF_SIZE];

int main() {
    pthread_t threads[2];
    int sock;
    struct sockaddr_in servAddr;

    printf("Input your Chat Name: ");
    scanf("%s", name);
    getchar(); // 接收换行符

    sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock < 0)
        error_handling("Failed socket()");

    servAddr.sin_family = AF_INET;
    servAddr.sin_port = htons(8888);

    // 使用 inet_pton 替代 inet_addr
    if (inet_pton(AF_INET, "127.0.0.1", &servAddr.sin_addr) <= 0) {
        error_handling("Invalid address/ Address not supported");
    }

    if (connect(sock, (struct sockaddr*)&servAddr, sizeof(servAddr)) < 0)
        error_handling("Failed connect()");
    printf("connect success\n");

    // 创建发送和接收线程
    pthread_create(&threads[0], NULL, send_msg, (void*)&sock);
    pthread_create(&threads[1], NULL, recv_msg, (void*)&sock);

    // 等待线程结束
    pthread_join(threads[0], NULL);
    pthread_join(threads[1], NULL);

    printf("Thread Over, Enter anything to exit.\n");
    getchar();
    close(sock);
    return 0;
}

void* send_msg(void* arg) {
    int sock = *((int*)arg);
    char name_msg[NAME_SIZE + BUF_SIZE];
    while (1) {
        fgets(msg, BUF_SIZE, stdin);
        if (!strcmp(msg, "q\n") || !strcmp(msg, "Q\n")) {
            close(sock);
            exit(0);
        }
        sprintf(name_msg, "[%s]: %s", name, msg);
        send(sock, name_msg, strlen(name_msg), 0);
    }
    return NULL;
}

void* recv_msg(void* arg) {
    int sock = *((int*)arg);
    char name_msg[NAME_SIZE + BUF_SIZE];
    int str_len;
    while (1) {
        str_len = recv(sock, name_msg, NAME_SIZE + BUF_SIZE - 1, 0);
        if (str_len <= 0) {
            return NULL; // 连接关闭或出错
        }
        name_msg[str_len] = 0;
        fputs(name_msg, stdout);
    }
    return NULL;
}

void error_handling(const char* msg) {
    perror(msg);
    exit(1);
}

3.运行结果

  1. 运行LinServer

  2. 运行LinClient

  3. 运行成功

6.用C语言在Linux中使用TCP协议与ipv6协议发送一句文本消息

1.使用C语言在Linux中使用ipv6地址创建服务端程序

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// LinServer.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h> // for close()
#include <arpa/inet.h> // for sockaddr_in6, inet_pton
#include <netdb.h> // for getaddrinfo
#include <errno.h>

#define PORT "8080" // 服务器端口
#define BACKLOG 10   // 最大连接数

int main() {
    struct addrinfo hints, *res;
    int listenfd, clientfd;
    struct sockaddr_storage client_addr;
    socklen_t addr_len = sizeof(client_addr);
    char buffer[1024];
    int recvResult;

    // 设置addrinfo结构
    memset(&hints, 0, sizeof(hints));
    hints.ai_family = AF_INET6; // 使用IPv6
    hints.ai_socktype = SOCK_STREAM; // TCP
    hints.ai_flags = AI_PASSIVE; // 服务器使用

    // 获取地址信息
    if (getaddrinfo(NULL, PORT, &hints, &res) != 0) {
        perror("getaddrinfo failed");
        return 1;
    }

    // 创建socket
    listenfd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
    if (listenfd < 0) {
        perror("socket failed");
        freeaddrinfo(res);
        return 1;
    }

    // 绑定socket
    if (bind(listenfd, res->ai_addr, res->ai_addrlen) < 0) {
        perror("bind failed");
        close(listenfd);
        freeaddrinfo(res);
        return 1;
    }

    freeaddrinfo(res); // 释放addrinfo结构

    // 开始监听
    if (listen(listenfd, BACKLOG) < 0) {
        perror("listen failed");
        close(listenfd);
        return 1;
    }

    printf("Server is listening on port %s...\n", PORT);

    // 接受客户端连接
    clientfd = accept(listenfd, (struct sockaddr*)&client_addr, &addr_len);
    if (clientfd < 0) {
        perror("accept failed");
        close(listenfd);
        return 1;
    }

    // 接收消息
    recvResult = recv(clientfd, buffer, sizeof(buffer) - 1, 0);
    if (recvResult > 0) {
        buffer[recvResult] = '\0'; // 添加字符串结束符
        printf("Received message: %s\n", buffer);
    } else if (recvResult < 0) {
        perror("recv failed");
    }

    // 关闭socket
    close(clientfd);
    close(listenfd);
    return 0;
}

2.使用C语言在Linux中使用ipv6地址创建客户端程序

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// LinClient.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h> // for close()
#include <arpa/inet.h> // for sockaddr_in6, inet_pton
#include <netdb.h> // for getaddrinfo
#include <errno.h>

#define PORT "8080" // 服务器端口
#define SERVER_ADDR "::1" // 服务器地址（本地IPv6地址）

int main() {
    struct addrinfo hints, *res;
    int sockfd;
    const char* message = "Hello, IPv6 TCP Server!";
    ssize_t sendResult;

    // 设置addrinfo结构
    memset(&hints, 0, sizeof(hints));
    hints.ai_family = AF_INET6; // 使用IPv6
    hints.ai_socktype = SOCK_STREAM; // TCP
    hints.ai_flags = 0;

    // 获取服务器地址信息
    if (getaddrinfo(SERVER_ADDR, PORT, &hints, &res) != 0) {
        perror("getaddrinfo failed");
        return 1;
    }

    // 创建socket
    sockfd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
    if (sockfd < 0) {
        perror("socket failed");
        freeaddrinfo(res);
        return 1;
    }

    // 连接到服务器
    if (connect(sockfd, res->ai_addr, res->ai_addrlen) < 0) {
        perror("connect failed");
        close(sockfd);
        freeaddrinfo(res);
        return 1;
    }

    freeaddrinfo(res); // 释放addrinfo结构

    // 发送消息
    sendResult = send(sockfd, message, strlen(message), 0);
    if (sendResult < 0) {
        perror("send failed");
        close(sockfd);
        return 1;
    }

    printf("Message sent: %s\n", message);

    // 关闭socket
    close(sockfd);
    return 0;
}

3.运行结果

  1. 运行LinServer

  2. 运行LinClient

  3. 运行成功