20.03.client.cpp

#define _WINSOCK_DEPRECATED_NO_WARNINGS
#pragma execution_character_set("utf-8")

#include <ws2tcpip.h>
#include <iostream>
#include <string>
#include <windows.h>
using namespace std;

#pragma comment (lib, "Ws2_32.lib")

#define DEFAULT_BUFLEN 4096
#define SERVER_IP "127.0.0.1"
#define DEFAULT_PORT "8888"

SOCKET client_socket;
wstring login;

DWORD WINAPI Sender(void* param) {
    while (true) {
        wstring message;
        getline(wcin, message);

        // формируем строку "login: текст"
        wstring formatted = login + L": " + message;
        string utf8(formatted.begin(), formatted.end()); // простая конвертация
        send(client_socket, utf8.c_str(), (int)utf8.size(), 0);
    }
}

DWORD WINAPI Receiver(void* param) {
    char response[DEFAULT_BUFLEN];
    while (true) {
        int result = recv(client_socket, response, DEFAULT_BUFLEN, 0);
        if (result <= 0) break;
        response[result] = '\0';
        wcout << L"Відповідь від сервера: " << response << endl;
    }
    return 0;
}

int main() {
    system("title Клієнт");

    // ввод логина и пароля
    wstring password;
    wcout << L"Введіть логін: ";
    getline(wcin, login);
    wcout << L"Введіть пароль: ";
    getline(wcin, password);

    WSADATA wsaData;
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        wcout << L"WSAStartup error\n";
        return 1;
    }

    addrinfo hints{}, * result = nullptr;
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_protocol = IPPROTO_TCP;

    if (getaddrinfo(SERVER_IP, DEFAULT_PORT, &hints, &result) != 0) {
        wcout << L"getaddrinfo error\n";
        WSACleanup();
        return 2;
    }

    client_socket = socket(result->ai_family, result->ai_socktype, result->ai_protocol);
    if (connect(client_socket, result->ai_addr, (int)result->ai_addrlen) == SOCKET_ERROR) {
        wcout << L"Connect error\n";
        WSACleanup();
        return 3;
    }
    freeaddrinfo(result);

    // отправляем логин+пароль серверу
    wstring credentials = login + L";" + password;
    string utf8(credentials.begin(), credentials.end());
    send(client_socket, utf8.c_str(), (int)utf8.size(), 0);

    system("cls");
    wcout << L"Авторизація успішна! Тепер можна писати повідомлення.\n";

    CreateThread(0, 0, Sender, 0, 0, 0);
    CreateThread(0, 0, Receiver, 0, 0, 0);

    Sleep(INFINITE);
}

20.03.server.cpp

#define _WINSOCK_DEPRECATED_NO_WARNINGS
#pragma execution_character_set("utf-8")

#include <winsock2.h>
#include <ws2tcpip.h>
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;

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

#define MAX_CLIENTS 20
#define DEFAULT_BUFLEN 4096

struct ClientInfo {
    string login;
    string password;
    string ip;
    int port;
};

SOCKET server_socket;
SOCKET client_socket[MAX_CLIENTS]{};
vector<ClientInfo> registeredClients;
vector<string> history;

int main() {
    setlocale(LC_ALL, "");
    system("title Сервер");

    WSADATA wsa;
    if (WSAStartup(MAKEWORD(2, 2), &wsa) != 0) {
        wcout << L"Помилка WSAStartup\n";
        return 1;
    }

    server_socket = socket(AF_INET, SOCK_STREAM, 0);
    if (server_socket == INVALID_SOCKET) {
        wcout << L"Не вдалося створити сокет\n";
        return 2;
    }

    sockaddr_in server{};
    server.sin_family = AF_INET;
    server.sin_addr.s_addr = INADDR_ANY;
    server.sin_port = htons(8888);

    if (bind(server_socket, (sockaddr*)&server, sizeof(server)) == SOCKET_ERROR) {
        wcout << L"Помилка прив'язки сокета\n";
        return 3;
    }

    listen(server_socket, MAX_CLIENTS);
    wcout << L"Сервер запущено. Очікування клієнтів...\n";

    fd_set readfds;
    sockaddr_in address;
    int addrlen = sizeof(sockaddr_in);

    while (true) {
        FD_ZERO(&readfds);
        FD_SET(server_socket, &readfds);
        for (int i = 0; i < MAX_CLIENTS; i++)
            if (client_socket[i] > 0) FD_SET(client_socket[i], &readfds);

        if (select(0, &readfds, NULL, NULL, NULL) == SOCKET_ERROR) {
            wcout << L"Помилка select\n";
            break;
        }

        if (FD_ISSET(server_socket, &readfds)) {
            SOCKET new_socket = accept(server_socket, (sockaddr*)&address, &addrlen);

            char buffer[DEFAULT_BUFLEN];
            int len = recv(new_socket, buffer, DEFAULT_BUFLEN, 0);
            if (len <= 0) continue;
            buffer[len] = '\0';

            string credentials(buffer);
            size_t sep = credentials.find(';');
            string login = credentials.substr(0, sep);
            string password = credentials.substr(sep + 1);

            auto it = find_if(registeredClients.begin(), registeredClients.end(),
                [&](const ClientInfo& c) { return c.login == login && c.password == password; });

            if (it == registeredClients.end()) {
                registeredClients.push_back({ login, password, inet_ntoa(address.sin_addr), ntohs(address.sin_port) });
                wcout << L"Новий клієнт зареєстрований: " << login.c_str() << endl;
            }
            else {
                wcout << L"Клієнт " << login.c_str() << L" увійшов." << endl;
            }

            for (int i = 0; i < MAX_CLIENTS; i++) {
                if (client_socket[i] == 0) {
                    client_socket[i] = new_socket;
                    break;
                }
            }
        }

        for (int i = 0; i < MAX_CLIENTS; i++) {
            SOCKET s = client_socket[i];
            if (FD_ISSET(s, &readfds)) {
                char msg[DEFAULT_BUFLEN];
                int len = recv(s, msg, DEFAULT_BUFLEN, 0);
                if (len <= 0) {
                    client_socket[i] = 0;
                    continue;
                }
                msg[len] = '\0';
                string message(msg);

                history.push_back(message + "\n");
                wcout << L"Отримано: " << message.c_str() << endl;

                for (int j = 0; j < MAX_CLIENTS; j++)
                    if (client_socket[j] != 0 && client_socket[j] != s)
                        send(client_socket[j], msg, len, 0);
            }
        }
    }

    WSACleanup();
    return 0;
}