int main(void)
{
    WORD sockVer;
    WSADATA wsaData;
    long int retVal;
 
    sockVer = MAKEWORD(2,2);
 
    WSAStartup(sockVer, &wsaData);
 
    //??????? ?????
    SOCKET servSock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
 
    if(servSock == INVALID_SOCKET)
    {
        printf("Unable to create socket\n");
        WSACleanup();
        return SOCKET_ERROR;
    }
	SOCKADDR_IN sin;
    sin.sin_family = PF_INET;
    sin.sin_port = htons(90);
    sin.sin_addr.s_addr = INADDR_ANY;
    SOCKET clientSock;
 

    retVal = bind(servSock, (LPSOCKADDR)&sin, sizeof(sin));
    if(retVal == SOCKET_ERROR)
    {
        printf("Unable to bind\n");
        WSACleanup();
        return SOCKET_ERROR;
    }
 
    //???????? ?????? ??????? ?????
    retVal = listen(servSock, 10);
    if(retVal == SOCKET_ERROR)
    {
        printf("Unable to listen\n");
        WSACleanup();
        return SOCKET_ERROR;
    }
    //???? ???????
 clientSock = accept(servSock, NULL, NULL);
    
    if(clientSock == INVALID_SOCKET)
    {
        printf("Unable to accept\n");
        WSACleanup();
        return SOCKET_ERROR;
    }
 
    char szReq[1024]; 
 while(todo){
    retVal = recv(clientSock, szReq, 1024, 0);
.....
s1=myparse(szReq);
.....
    if(retVal == SOCKET_ERROR)
    {
        printf("Unable to recv\n");
        return SOCKET_ERROR;
    }
    char *szResp = "Response";
    
  
    

 
    if(retVal == SOCKET_ERROR)
    {
        printf("Unable to send\n");
        return SOCKET_ERROR;
    }

    retVal = send(clientSock, s1.c_str(), s1.length(), 0);
    
    ZeroMemory(szReq,1024);
    
}
    closesocket(clientSock);
    closesocket(servSock);
 
    WSACleanup();
    

    system("PAUSE");
    return EXIT_SUCCESS;

void Awake(){
		ip = "127.0.0.1";
		//ip = "37.151.21.7";
		port = 90;
		s = "";
		ss = "";
		localEndPoint = new IPEndPoint(IPAddress.Parse(ip), port);
		// Create a TCP/IP socket.
		client1 = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
		try{
			client1.Connect (localEndPoint);
			Debug.Log ("Connected");
		}
		catch{
			Debug.Log("Can't connect");		
		}
....
}

void Update () {
		byte[] Buffer;
		string data = "";
		Buffer = Encoding.ASCII.GetBytes(data);
		Array.Clear (Buffer,0, Buffer.Length);
		client1.Receive (Buffer);
		data = Encoding.ASCII.GetString (Buffer);
		//Debug.Log (data);
		s = s + data;
		.....

		if (ss != "") {
				
			myparse (ss);
		}
		
		Array.Clear (Buffer,0, Buffer.Length);
		}

	void OnGUI () {
		byte[] Buffer;
		string data;
		
		
		data = "begin \n";
		Buffer = Encoding.ASCII.GetBytes(data);
		client1.Send (Buffer);
		
		Array.Clear (Buffer,0, Buffer.Length);
		
		data = "player " + Player1.transform.localPosition.x.ToString () + " " +
			Player1.transform.localPosition.y.ToString () + " " +
				Player1.transform.localPosition.z.ToString () + " \n";
		Buffer = Encoding.ASCII.GetBytes(data);
		client1.Send (Buffer);
		

		Array.Clear (Buffer,0, Buffer.Length);	
		data = "the_end \n";
		Buffer = Encoding.ASCII.GetBytes(data);
		client1.Send (Buffer);
		
		Array.Clear (Buffer,0, Buffer.Length);		

	}

msg[256]
...//тут чтение в msg
S=S+msg;
...

string S="";
...
while(b){
  msg[256];
  ...
  S=S+msg;
  cout<<sizeof(msg)<<"  "<s.length()<<"\n";
}

256 276

cout<<sizeof(msg)<<"  "<S.length()<<"\n";

cout<<sizeof(msg)<<"  "<S.length()<<"\n";