Select TCP Server

// selectTCPServer.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "conio.h"
#include "stdio.h"
#include "winsock2.h"
#include "ws2tcpip.h"

SOCKET s, c[1204];
int nClient = 0;
SOCKADDR_IN sAddr;
SOCKADDR_IN cAddr;

DWORD WINAPI SenderThread(LPVOID Param) {
    char buf[1024];
    char msg[1024];
    while (true) {
        fgets(buf, 1024, stdin);
        sprintf(msg, "Server: %s\n", buf);
        for (int i = 0; i < nClient; i++)
            if (c[i != 0]) {
                send(c[i], msg, strlen(msg), 0);
            }
    }
    return 0;
}


int main()
{
    WSADATA wsadata;
    int ret = WSAStartup(MAKEWORD(2, 2), &wsadata);
    if (ret == SOCKET_ERROR) printf("Create winsock fail.");
    else printf("Create winsock success.\n");

    s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

    sAddr.sin_family = AF_INET;
    sAddr.sin_port = htons(10008);
    sAddr.sin_addr.s_addr = htonl(INADDR_ANY);

    int clientlen = sizeof(cAddr);

    for (int j = 0; j < 1024; j++) {
        c[j] = 0;
    }


    c[0] = s;
    nClient = 1;

    ret = bind(s, (sockaddr*)&sAddr, sizeof(sAddr));
    ret = listen(s, 16);

    fd_set fdread;
    int i;
    char buf[1024];
    char msg[1024];
    int len;
    timeval tm;
    bool tachluong = false;

    while (true) {
        FD_ZERO(&fdread);
        FD_SET(s, &fdread);
        for (i = 0; i < nClient; i++) {
            if (c[i] != 0) FD_SET(c[i], &fdread);
        }

        tm.tv_sec = 5;
        tm.tv_usec = 0;

        ret = select(0, &fdread, 0, 0, &tm);
        if (ret == SOCKET_ERROR) break;
        if (ret == 0) {
            printf("Khong co su kien nao xay ra\n");
            continue;
        }
        if (FD_ISSET(s, &fdread)) {
            for (i = 1; i < nClient; i++)
                if (c[i] == 0) break;
            c[i] = accept(s, (sockaddr*)&cAddr, &clientlen);
            printf("Client %d connectd\n", i);
            char * szHello = "Hello client\n";
            send(c[i], szHello, strlen(szHello), 0);
            if (tachluong == false) {
                CreateThread(0, 0, SenderThread, 0, 0, 0);
                tachluong = true;
            }
            if (i == nClient) nClient++;
        }
        for (i = 1; i < nClient; i++) {
            if (FD_ISSET(c[i], &fdread)) {
                len = recv(c[i], buf, 1024, 0);
                if (len > 0) {
                    buf[len] = 0;
                    printf("Client %d: %s\n", i, buf);
                    sprintf(msg, "Client %d: %s\n", i, buf);
                    for (int k = 1; k < nClient; k++) {
                        if (k != i && c[k] != 0)
                            send(c[k], msg, strlen(msg), 0);
                    }
                }
                else {
                    closesocket(c[i]);
                    c[i] = 0;
                    printf("Client %d ngat ket noi\n", i);
                }

            }
        }
    }

    closesocket(s);
    WSACleanup();


    return 0;
}