2.用C语言在windows中使用UDP协议发送文本消息

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用C语言在windows中使用UDP协议发送文本消息

1.用C语言在windows中使用UDP协议发送一句文本消息

1.使用C语言在windows中创建服务端程序接收一句文本消息

//WinServer.c
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdio.h>
#include <stdlib.h>

#pragma comment(lib, "WS2_32.lib")

#define BUF_SIZE 256

int main() {
    WSADATA wsaData;
    SOCKET sock;
    struct sockaddr_in serverAddr, clientAddr;
    char buffer[BUF_SIZE];
    int clientAddrLen = sizeof(clientAddr);

    // 初始化 Winsock
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        printf("WSAStartup failed. Error Code: %d\n", WSAGetLastError());
        return 1;
    }

    // 创建 UDP 套接字
    sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
    if (sock == INVALID_SOCKET) {
        printf("Socket creation failed. Error Code: %d\n", WSAGetLastError());
        WSACleanup();
        return 1;
    }

    // 填充服务器地址信息
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_port = htons(8888); // 监听端口
    serverAddr.sin_addr.s_addr = INADDR_ANY; // 监听所有可用的接口

    // 绑定套接字到地址
    if (bind(sock, (struct sockaddr*)&serverAddr, sizeof(serverAddr)) == SOCKET_ERROR) {
        printf("Bind failed. Error Code: %d\n", WSAGetLastError());
        closesocket(sock);
        WSACleanup();
        return 1;
    }

    printf("UDP server is listening on port 8888...\n");

    // 循环接收消息
    while (1) {
        int recvLen = recvfrom(sock, buffer, BUF_SIZE, 0, (struct sockaddr*)&clientAddr, &clientAddrLen);
        if (recvLen == SOCKET_ERROR) {
            printf("Receive failed. Error Code: %d\n", WSAGetLastError());
            break;
        }

        // 将接收到的消息以 null 结尾
        buffer[recvLen] = '\0';

        // 打印接收到的消息
        char clientIP[INET_ADDRSTRLEN];
        inet_ntop(AF_INET, &clientAddr.sin_addr, clientIP, sizeof(clientIP));
        printf("Received message from %s:%d\n", clientIP, ntohs(clientAddr.sin_port));
        printf("%s", buffer);
    }

    // 关闭套接字
    closesocket(sock);
    WSACleanup();
    return 0;
}

2.使用C语言在windows中创建客户端程序发送一句文本消息

//WinClient.c
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdio.h>
#include <stdlib.h>

#pragma comment(lib, "WS2_32.lib")

#define BUF_SIZE 256

int main() {
    WSADATA wsaData;
    SOCKET sock;
    struct sockaddr_in serverAddr;
    char message[BUF_SIZE];

    // 初始化 Winsock
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        printf("WSAStartup failed. Error Code: %d\n", WSAGetLastError());
        return 1;
    }

    // 创建 UDP 套接字
    sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
    if (sock == INVALID_SOCKET) {
        printf("Socket creation failed. Error Code: %d\n", WSAGetLastError());
        WSACleanup();
        return 1;
    }

    // 填充目标地址信息
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_port = htons(8888); // 目标端口

    // 使用 inet_pton 替代 inet_addr
    if (inet_pton(AF_INET, "127.0.0.1", &serverAddr.sin_addr) <= 0) {
        printf("Invalid address/ Address not supported \n");
        closesocket(sock);
        WSACleanup();
        return 1;
    }

    // 输入要发送的消息
    printf("Enter message to send: ");
    fgets(message, BUF_SIZE, stdin);

    // 发送消息
    int sendResult = sendto(sock, message, strlen(message), 0, (struct sockaddr*)&serverAddr, sizeof(serverAddr));
    if (sendResult == SOCKET_ERROR) {
        printf("Send failed. Error Code: %d\n", WSAGetLastError());
        closesocket(sock);
        WSACleanup();
        return 1;
    }

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

    // 关闭套接字
    closesocket(sock);
    WSACleanup();
    return 0;
}

3.运行结果

1. 运行WinServer.exe
2. 运行WinClient.exe
3. 运行成功

2.用C语言在windows中使用UDP协议多次发送文本消息

1.使用C语言在windows中创建服务端程序多次接收文本消息

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>
#include <ws2tcpip.h>

#pragma comment(lib, "ws2_32.lib") // 链接 Winsock 库

int main() {
    WSADATA wsaData;
    SOCKET serverSocket;
    struct sockaddr_in server, client;
    int clientSize;
    char buffer[1024];
    int recvSize;

    // 初始化 Winsock
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        printf("Failed to initialize Winsock. Error Code: %d\n", WSAGetLastError());
        return 1;
    }

    // 创建 socket
    serverSocket = socket(AF_INET, SOCK_DGRAM, 0);
    if (serverSocket == INVALID_SOCKET) {
        printf("Could not create socket. Error Code: %d\n", WSAGetLastError());
        WSACleanup();
        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)) == SOCKET_ERROR) {
        printf("Bind failed. Error Code: %d\n", WSAGetLastError());
        closesocket(serverSocket);
        WSACleanup();
        return 1;
    }

    printf("Waiting for incoming messages...\n");

    clientSize = sizeof(client);
    // 接收消息
    while (1) {
        recvSize = recvfrom(serverSocket, buffer, sizeof(buffer) - 1, 0, (struct sockaddr*)&client, &clientSize);
        if (recvSize == SOCKET_ERROR) {
            printf("Receive failed. Error Code: %d\n", WSAGetLastError());
            break;
        }

        buffer[recvSize] = '\0'; // 添加字符串结束符
        char clientIP[INET_ADDRSTRLEN];
        inet_ntop(AF_INET, &client.sin_addr, clientIP, sizeof(clientIP)); // 使用 inet_ntop
        printf("Received message from %s:%d: %s\n", clientIP, ntohs(client.sin_port), buffer);
    }

    // 关闭 socket
    closesocket(serverSocket);
    WSACleanup();
    return 0;
}

2.使用C语言在windows中创建客户端程序多次发送文本消息

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>
#include <ws2tcpip.h>

#pragma comment(lib, "ws2_32.lib") // 链接 Winsock 库

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

    // 初始化 Winsock
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        printf("Failed to initialize Winsock. Error Code: %d\n", WSAGetLastError());
        return 1;
    }

    // 创建 socket
    sock = socket(AF_INET, SOCK_DGRAM, 0);
    if (sock == INVALID_SOCKET) {
        printf("Could not create socket. Error Code: %d\n", WSAGetLastError());
        WSACleanup();
        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) {
        printf("Invalid address/ Address not supported \n");
        closesocket(sock);
        WSACleanup();
        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 = sendto(sock, message, strlen(message), 0, (struct sockaddr*)&server, sizeof(server));
        if (sendResult == SOCKET_ERROR) {
            printf("Send failed. Error Code: %d\n", WSAGetLastError());
            break;
        }
        else {
            printf("Message sent: %s\n", message);
        }
    }

    // 关闭 socket
    closesocket(sock);
    WSACleanup();
    return 0;
}

3.运行结果

1. 运行WinServer.exe

2. 运行WinClient.exe

3. 运行成功

3.用C语言在windows中使用UDP协议客户端退出后可以再次连接服务器

1.使用C语言在windows中创建服务端程序断开后等待客户端连接

// WinServer.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>
#include <ws2tcpip.h>

#pragma comment(lib, "ws2_32.lib") // 链接 Winsock 库

int main() {
    WSADATA wsaData;
    SOCKET serverSocket;
    struct sockaddr_in server, client;
    int clientSize;
    char buffer[1024];
    int recvSize;

    // 初始化 Winsock
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        printf("Failed to initialize Winsock. Error Code: %d\n", WSAGetLastError());
        return 1;
    }

    // 创建 socket
    serverSocket = socket(AF_INET, SOCK_DGRAM, 0);
    if (serverSocket == INVALID_SOCKET) {
        printf("Could not create socket. Error Code: %d\n", WSAGetLastError());
        WSACleanup();
        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)) == SOCKET_ERROR) {
        printf("Bind failed. Error Code: %d\n", WSAGetLastError());
        closesocket(serverSocket);
        WSACleanup();
        return 1;
    }

    printf("Waiting for incoming messages...\n");
    clientSize = sizeof(client);

    // 循环接收消息
    while (1) {
        // 接收消息
        recvSize = recvfrom(serverSocket, buffer, sizeof(buffer) - 1, 0, (struct sockaddr*)&client, &clientSize);
        if (recvSize == SOCKET_ERROR) {
            printf("Receive failed. Error Code: %d\n", WSAGetLastError());
            continue;
        }

        buffer[recvSize] = '\0'; // 添加字符串结束符
        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("Received message from %s:%d: %s\n", clientIP, ntohs(client.sin_port), buffer);
    }

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

2.使用C语言在windows中创建客户端程序退出后再次连接服务端

// WinClient.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>
#include <ws2tcpip.h>

#pragma comment(lib, "ws2_32.lib") // 链接 Winsock 库

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

    // 初始化 Winsock
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        printf("Failed to initialize Winsock. Error Code: %d\n", WSAGetLastError());
        return 1;
    }

    // 创建 socket
    sock = socket(AF_INET, SOCK_DGRAM, 0);
    if (sock == INVALID_SOCKET) {
        printf("Could not create socket. Error Code: %d\n", WSAGetLastError());
        WSACleanup();
        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) {
        printf("Invalid address/ Address not supported \n");
        closesocket(sock);
        WSACleanup();
        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 = sendto(sock, message, strlen(message), 0, (struct sockaddr*)&server, sizeof(server));
        if (sendResult == SOCKET_ERROR) {
            printf("Send failed. Error Code: %d\n", WSAGetLastError());
            break;
        } else {
            printf("Message sent: %s\n", message);
        }
    }

    // 关闭 socket
    closesocket(sock);
    WSACleanup();
    return 0;
}

3.运行结果

1. 运行WinServer.exe

2. 运行WinClient.exe

3. 运行成功

4.用C语言在windows中使用UDP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windows中创建服务端接收文本消息后再发送到客户端

// WinServer.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>
#include <ws2tcpip.h>

#pragma comment(lib, "ws2_32.lib") // 链接 Winsock 库

int main() {
    WSADATA wsaData;
    SOCKET serverSocket;
    struct sockaddr_in server, client;
    int clientSize;
    char buffer[1024];
    int recvSize;

    // 初始化 Winsock
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        printf("Failed to initialize Winsock. Error Code: %d\n", WSAGetLastError());
        return 1;
    }

    // 创建 socket
    serverSocket = socket(AF_INET, SOCK_DGRAM, 0);
    if (serverSocket == INVALID_SOCKET) {
        printf("Could not create socket. Error Code: %d\n", WSAGetLastError());
        WSACleanup();
        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)) == SOCKET_ERROR) {
        printf("Bind failed. Error Code: %d\n", WSAGetLastError());
        closesocket(serverSocket);
        WSACleanup();
        return 1;
    }

    printf("Waiting for incoming messages...\n");
    clientSize = sizeof(client);

    // 循环接收消息
    while (1) {
        // 接收消息
        recvSize = recvfrom(serverSocket, buffer, sizeof(buffer) - 1, 0, (struct sockaddr*)&client, &clientSize);
        if (recvSize == SOCKET_ERROR) {
            printf("Receive failed. Error Code: %d\n", WSAGetLastError());
            continue;
        }

        buffer[recvSize] = '\0'; // 添加字符串结束符
        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("Received message from %s:%d: %s\n", clientIP, ntohs(client.sin_port), buffer);

        // 发送回客户端
        sendto(serverSocket, buffer, recvSize, 0, (struct sockaddr*)&client, clientSize);
    }

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

2.使用C语言在windows中创建客户端程序接收与发送文本消息

// WinClient.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>
#include <ws2tcpip.h>

#pragma comment(lib, "ws2_32.lib") // 链接 Winsock 库

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

    // 初始化 Winsock
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        printf("Failed to initialize Winsock. Error Code: %d\n", WSAGetLastError());
        return 1;
    }

    // 创建 socket
    sock = socket(AF_INET, SOCK_DGRAM, 0);
    if (sock == INVALID_SOCKET) {
        printf("Could not create socket. Error Code: %d\n", WSAGetLastError());
        WSACleanup();
        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) {
        printf("Invalid address/ Address not supported \n");
        closesocket(sock);
        WSACleanup();
        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 = sendto(sock, message, strlen(message), 0, (struct sockaddr*)&server, sizeof(server));
        if (sendResult == SOCKET_ERROR) {
            printf("Send failed. Error Code: %d\n", WSAGetLastError());
            break;
        } else {
            printf("Message sent: %s\n", message);
        }

        // 接收来自服务器的消息
        recvSize = recvfrom(sock, buffer, sizeof(buffer) - 1, 0, NULL, NULL);
        if (recvSize > 0) {
            buffer[recvSize] = '\0'; // 添加字符串结束符
            printf("Received from server: %s\n", buffer);
        } else if (recvSize == SOCKET_ERROR) {
            printf("Receive failed. Error Code: %d\n", WSAGetLastError());
            break;
        }
    }

    // 关闭 socket
    closesocket(sock);
    WSACleanup();
    return 0;
}

3.运行结果

1. 运行WinServer.exe

2. 运行WinClient.exe

3. 运行成功

5.用C语言在windows中使用UDP协议让两个客户端之间可以相互发送文本消息(unsuccess)

1.使用C语言在windows中创建服务端接收与转发文本消息到所有客户端中

2.使用C语言在windows中创建客户端程序接收与发送文本消息

3.运行结果

1. 运行WinServer.exe

2. 运行WinClient.exe

3. 运行

6.用C语言在windows中使用UDP协议与ipv6协议发送一句文本消息

1.使用C语言在windows中使用ipv6地址创建服务端程序

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>
#include <ws2tcpip.h>

#pragma comment(lib, "ws2_32.lib")

#define PORT "8080" // 服务器端口
#define BUF_SIZE 1024 // 缓冲区大小

int main() {
    WSADATA wsaData;
    struct addrinfo hints, * res;
    SOCKET sockfd;
    struct sockaddr_storage client_addr;
    socklen_t addr_len = sizeof(client_addr);
    char buffer[BUF_SIZE];
    int recvResult;

    // 初始化Winsock
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        printf("WSAStartup failed: %d\n", WSAGetLastError());
        return 1;
    }

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

    // 获取地址信息
    if (getaddrinfo(NULL, PORT, &hints, &res) != 0) {
        printf("getaddrinfo failed: %d\n", WSAGetLastError());
        WSACleanup();
        return 1;
    }

    // 创建socket
    sockfd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
    if (sockfd == INVALID_SOCKET) {
        printf("socket failed: %d\n", WSAGetLastError());
        freeaddrinfo(res);
        WSACleanup();
        return 1;
    }

    // 绑定socket
    if (bind(sockfd, res->ai_addr, (int)res->ai_addrlen) == SOCKET_ERROR) {
        printf("bind failed: %d\n", WSAGetLastError());
        closesocket(sockfd);
        freeaddrinfo(res);
        WSACleanup();
        return 1;
    }

    freeaddrinfo(res); // 释放addrinfo结构

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

    // 接收消息
    while (1) {
        recvResult = recvfrom(sockfd, buffer, sizeof(buffer) - 1, 0, (struct sockaddr*)&client_addr, &addr_len);
        if (recvResult == SOCKET_ERROR) {
            printf("recvfrom failed: %d\n", WSAGetLastError());
            continue;
        }

        buffer[recvResult] = '\0'; // 添加字符串结束符
        printf("Received message: %s\n", buffer);

        // 发送回客户端
        sendto(sockfd, buffer, recvResult, 0, (struct sockaddr*)&client_addr, addr_len);
    }

    // 关闭socket
    closesocket(sockfd);
    WSACleanup();
    return 0;
}

2.使用C语言在windows中使用ipv6地址创建客户端程序

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>
#include <ws2tcpip.h>

#pragma comment(lib, "ws2_32.lib")

#define PORT "8080" // 服务器端口
#define SERVER_ADDR "::1" // 服务器地址（本地IPv6地址）
#define BUF_SIZE 256 // 缓冲区大小

int main() {
    WSADATA wsaData;
    struct addrinfo hints, * res;
    SOCKET sockfd;
    const char* message = "Hello, UDP Server!";
    int sendResult;

    // 初始化Winsock
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        printf("WSAStartup failed: %d\n", WSAGetLastError());
        return 1;
    }

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

    // 获取服务器地址信息
    if (getaddrinfo(SERVER_ADDR, PORT, &hints, &res) != 0) {
        printf("getaddrinfo failed: %d\n", WSAGetLastError());
        WSACleanup();
        return 1;
    }

    // 创建socket
    sockfd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
    if (sockfd == INVALID_SOCKET) {
        printf("socket failed: %d\n", WSAGetLastError());
        freeaddrinfo(res);
        WSACleanup();
        return 1;
    }

    // 发送消息
    sendResult = sendto(sockfd, message, (int)strlen(message), 0, res->ai_addr, (int)res->ai_addrlen);
    if (sendResult == SOCKET_ERROR) {
        printf("sendto failed: %d\n", WSAGetLastError());
        closesocket(sockfd);
        WSACleanup();
        return 1;
    }

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

    // 接收来自服务器的消息
    char buffer[BUF_SIZE];
    struct sockaddr_storage from_addr;
    socklen_t addr_len = sizeof(from_addr);
    int recvResult = recvfrom(sockfd, buffer, sizeof(buffer) - 1, 0, (struct sockaddr*)&from_addr, &addr_len);
    if (recvResult > 0) {
        buffer[recvResult] = '\0'; // 添加字符串结束符
        printf("Received from server: %s\n", buffer);
    }
    else {
        printf("recvfrom failed: %d\n", WSAGetLastError());
    }

    // 关闭socket
    closesocket(sockfd);
    WSACleanup();
    return 0;
}

3.运行结果

1. 运行WinServer.exe

2. 运行WinClient.exe

3. 运行成功