socket基本

fd_set用法：

http://blog.sina.com.cn/s/blog_5c8d13830100erzs.htm 

socket连接：

lpszHost="127.0.0.1"
    nPort = 9200
    m_Socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); 
    
    if (m_Socket == SOCKET_ERROR)   
    { 
        return false;   
    }

    // 构造sockaddr_in结构
    sockaddr_in    ClientAddr;
    ClientAddr.sin_family    = AF_INET;
    ClientAddr.sin_port    = htons(nPort);
    hostent* pHostent = gethostbyname((char*)lpszHost);
    ClientAddr.sin_addr = *((struct in_addr *)pHostent->h_addr);
    
    if (connect(m_Socket, (SOCKADDR *)&ClientAddr, sizeof(ClientAddr)) == SOCKET_ERROR)   
    {
        return false;
    }
    m_bIsRunning = true;
    m_hThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)WorkThread, (LPVOID)this, 0, 0);