чат на TCP

Client.cpp

#include <ws2tcpip.h>
#include <windows.h>
#include <iostream>
#include <string>
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;
string nick;

DWORD WINAPI Sender(void* param) {
    while (true) {
        char query[DEFAULT_BUFLEN];
        cin.getline(query, DEFAULT_BUFLEN);

        string message = nick + ": " + query;
        send(client_socket, message.c_str(), message.size(), 0);
    }
}

DWORD WINAPI Receiver(void* param) {
    while (true) {
        char response[DEFAULT_BUFLEN];
        int result = recv(client_socket, response, DEFAULT_BUFLEN, 0);

        if (result <= 0) continue;

        response[result] = '\0';
        cout << response << "\n";
    }
}

BOOL ExitHandler(DWORD whatHappening) {
    switch (whatHappening) {
    case CTRL_C_EVENT:
    case CTRL_BREAK_EVENT:
    case CTRL_CLOSE_EVENT:
    case CTRL_LOGOFF_EVENT:
    case CTRL_SHUTDOWN_EVENT:
        cout << "Shutting down...\n";
        Sleep(1000);
        send(client_socket, "off", 3, 0);
        return TRUE;
    default:
        return FALSE;
    }
}

int main() {
    cout << "Enter your nickname: ";
    getline(cin, nick);

    SetConsoleCtrlHandler((PHANDLER_ROUTINE)ExitHandler, true);
    system("title Client");

    WSADATA wsaData;
    int iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
    if (iResult != 0) {
        cout << "WSAStartup failed with error: " << iResult << "\n";
        return 1;
    }

    addrinfo hints{};
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_protocol = IPPROTO_TCP;

    addrinfo* result = nullptr;
    iResult = getaddrinfo(SERVER_IP, DEFAULT_PORT, &hints, &result);
    if (iResult != 0) {
        cout << "getaddrinfo failed with error: " << iResult << "\n";
        WSACleanup();
        return 2;
    }

    addrinfo* ptr = nullptr;
    for (ptr = result; ptr != NULL; ptr = ptr->ai_next) {
        client_socket = socket(ptr->ai_family, ptr->ai_socktype, ptr->ai_protocol);
        if (client_socket == INVALID_SOCKET) {
            cout << "Socket creation failed with error: " << WSAGetLastError() << "\n";
            WSACleanup();
            return 3;
        }

        iResult = connect(client_socket, ptr->ai_addr, (int)ptr->ai_addrlen);
        if (iResult == SOCKET_ERROR) {
            closesocket(client_socket);
            client_socket = INVALID_SOCKET;
            continue;
        }
        break;
    }

    freeaddrinfo(result);

    if (client_socket == INVALID_SOCKET) {
        cout << "Unable to connect to server!\n";
        WSACleanup();
        return 5;
    }

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

    Sleep(INFINITE);
}

Server.cpp

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

#define MAX_CLIENTS 20
#define DEFAULT_BUFLEN 4096

#pragma comment(lib, "ws2_32.lib")
#pragma warning(disable:4996)

SOCKET server_socket;
vector<string> history;

int main() {
    setlocale(0, "");
    system("title Server");

    cout << "Starting server... done.\n";
    WSADATA wsa;
    if (WSAStartup(MAKEWORD(2, 2), &wsa) != 0) {
        cout << "Failed. Error code: " << WSAGetLastError() << "\n";
        return 1;
    }

    if ((server_socket = socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET) {
        cout << "Failed to create socket: " << WSAGetLastError() << "\n";
        return 2;
    }
    cout << "Server socket created... done.\n";

    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) {
        cout << "Bind failed with error code: " << WSAGetLastError() << "\n";
        return 3;
    }

    cout << "Socket bind... done.\n";
    listen(server_socket, MAX_CLIENTS);

    cout << "Server is waiting for incoming connections...\nPlease start one or more client applications.\n";

    fd_set readfds;
    SOCKET client_socket[MAX_CLIENTS]{};

    while (true) {
        FD_ZERO(&readfds);
        FD_SET(server_socket, &readfds);

        for (int i = 0; i < MAX_CLIENTS; i++) {
            SOCKET s = client_socket[i];
            if (s > 0) FD_SET(s, &readfds);
        }

        if (select(0, &readfds, NULL, NULL, NULL) == SOCKET_ERROR) {
            cout << "Select function failed with error code: " << WSAGetLastError() << "\n";
            return 4;
        }

        SOCKET new_socket;
        sockaddr_in address;
        int addrlen = sizeof(sockaddr_in);

        if (FD_ISSET(server_socket, &readfds)) {
            if ((new_socket = accept(server_socket, (sockaddr*)&address, &addrlen)) < 0) {
                perror("Accept function error");
                return 5;
            }

            for (int i = 0; i < history.size(); i++) {
                send(new_socket, history[i].c_str(), history[i].size(), 0);
            }

            cout << "New connection, socket fd: " << new_socket
                << ", IP: " << inet_ntoa(address.sin_addr)
                << ", Port: " << ntohs(address.sin_port) << "\n";

            for (int i = 0; i < MAX_CLIENTS; i++) {
                if (client_socket[i] == 0) {
                    client_socket[i] = new_socket;
                    cout << "Added to socket list at index " << i << "\n";
                    break;
                }
            }
        }

        for (int i = 0; i < MAX_CLIENTS; i++) {
            SOCKET s = client_socket[i];
            if (FD_ISSET(s, &readfds)) {
                getpeername(s, (sockaddr*)&address, (int*)&addrlen);

                char client_message[DEFAULT_BUFLEN];
                int client_message_length = recv(s, client_message, DEFAULT_BUFLEN, 0);

                if (client_message_length <= 0) {
                    cout << "Client #" << i << " disconnected\n";
                    client_socket[i] = 0;
                    continue;
                }

                client_message[client_message_length] = '\0';
                string check_exit = client_message;

                if (check_exit == "off") {
                    cout << "Client #" << i << " disconnected\n";
                    client_socket[i] = 0;
                }
                else {
                    string temp = client_message;
                    temp += "\n";
                    history.push_back(temp);

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

    WSACleanup();
}