7b) UDP Client-Server Communication (Windows)

Files:
- server.cpp (UDP Server)
- client.cpp (UDP Client)

SERVER (server.cpp):
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#include <iostream>
#include <winsock2.h>

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

int main() {
    WSADATA wsa;
    WSAStartup(MAKEWORD(2,2), &wsa);

    SOCKET serverSocket = socket(AF_INET, SOCK_DGRAM, 0);

    sockaddr_in serverAddr;
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_addr.s_addr = INADDR_ANY;
    serverAddr.sin_port = htons(5001);

    bind(serverSocket, (sockaddr*)&serverAddr, sizeof(serverAddr));

    char buffer[1024];
    sockaddr_in clientAddr;
    int clientAddrSize = sizeof(clientAddr);

    std::cout << "[+] UDP Server listening on port 5001..." << std::endl;

    while (true) {
        int bytesReceived = recvfrom(serverSocket, buffer, sizeof(buffer) - 1, 0,
                                     (sockaddr*)&clientAddr, &clientAddrSize);
        if (bytesReceived > 0) {
            buffer[bytesReceived] = '\0';
            std::cout << "Message from client: " << buffer << std::endl;
        }
    }

    closesocket(serverSocket);
    WSACleanup();
    return 0;
}
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Terminal Command (Windows):
1) g++ server.cpp -o server -lws2_32
2) .\server.exe
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CLIENT (client.cpp):
---------------------------------------------------------------
#include <iostream>
#include <winsock2.h>

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

int main() {
    WSADATA wsa;
    WSAStartup(MAKEWORD(2,2), &wsa);

    SOCKET clientSocket = socket(AF_INET, SOCK_DGRAM, 0);

    sockaddr_in serverAddr;
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_port = htons(5001);
    serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1"); // same machine

    std::string message;
    std::cout << "Enter message to send: ";
    std::getline(std::cin, message);

    sendto(clientSocket, message.c_str(), message.length(), 0,
           (sockaddr*)&serverAddr, sizeof(serverAddr));

    std::cout << "Message sent!" << std::endl;

    closesocket(clientSocket);
    WSACleanup();
    return 0;
}
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Terminal Command (Windows):
1) g++ client.cpp -o client -lws2_32
2) .\client.exe