Messages

1

Network / Re: How to create a UDP "chat"

« on: December 28, 2012, 11:47:41 am »

I nerver said that I want a finished code.

I chose UDP because I thought it was a bit simpler than TCP. I am a newbie in network programming, so I want to learn the basics first (using that example).

So yes, I am doing that program because I just want to experiment.

On the other hand, I want to make a simple communication between the server and the client.
More exactly: the server and the client must have the sending and receiving properties so that the server can receive messages from the client and to send messages too, as same as the client. 


I am stuck in the following situation: the server must receive messages (as it does in the code below) but it also has to send messages. Now, I don't know how to make a kind of algorithm which knows when to send the messages at the appropriate time (if I type something in the server - application and I hit enter, the client should see my message in his application; but what if the client is typing in the same time I hit enter? does he receive my message?);  the same situation is in the client - application. In some way, both applications must wait for the message or...someting like that.

I've seen that chat - application made using TCP sockets but it was a bit hard to understand for me because I  don't know many things about threads and mutex or whatever.

I want something as simple as possible.

Thank you respectfully.

2

Network / How to create a UDP "chat"

« on: December 27, 2012, 09:30:07 pm »

Hello!

I try to create a...kind of chat using a UDP socket.

I started with the examples in the tutorial about UDP sockets and I modified them a bit.

I want to create two separate programs (the server and the client) and to communicate each other. Until now, only the client can send messages to the server.

Here is the code for the server application:

#include<SFML/Network.hpp>
#include<iostream>
#include<cstring>

void DoServerUDP(unsigned short Port)
{
    // Create a UDP socket for communicating with clients
    sf::SocketUDP Server;

    // Bind it to the specified port
    if (!Server.Bind(Port))
        return;

    // Receive a message from anyone
    sf::IPAddress ClientAddress = sf::IPAddress::LocalHost;
    unsigned short ClientPort;
    char Message[128];
    char SendingMessage[200];
    std::size_t Received;

    int i=0;
    while(i<100)
    {

          Server.Receive(Message, sizeof(Message), Received, ClientAddress, ClientPort);
          std::cout <<"Client: "<< Message << "\n" << std::endl;
       /*   std::cin.getline(SendingMessage, 200);
          Server.Send(SendingMessage,sizeof(SendingMessage), ClientAddress, ClientPort);*/

        i++;
    }

    // Close the socket when we're done
    Server.Close();
}
int main()
{
    const int port = 2343;
    std::cout<<"Hello! The UDP server has been started. Now, the server waits for messages.";
    std::cout<<"\n";
    DoServerUDP(port);
    std::cout<<"Press enter to exit...";
    std::cin.ignore(10000, '\n');
    std::cin.ignore(10000, '\n');
    return EXIT_SUCCESS;
}
 

And this is the code for the client application:

#include<SFML/Network.hpp>
#include<iostream>
#include<cstring>

void DoClientUDP(unsigned short Port)
{
    // Ask for server address
    sf::IPAddress ServerAddress;
    do
    {
        std::cout << "Type address or name of the server to send the message to : ";
        std::cin  >> ServerAddress;
    }
    while (!ServerAddress.IsValid());
    char Message[3000];
    // Create a UDP socket for communicating with server
    sf::SocketUDP Client;

    std::cout<<"You will now start the conversation with server: ";
    std::cin.getline(Message, 3000);
    std::size_t Received;
    char MessageReceived[256];

    int i=0;
    while(i<100)
    {


       Client.Send(Message, sizeof(Message), ServerAddress, Port);

       std::cin.getline(Message, 3000);

      i++;

    }
    // Close the socket when we're done
    Client.Close();
}

int main()
{
    const int port = 2343;
    std::cout<<"Welcome to the Client application!";
    std::cout<<"\n";
    DoClientUDP(port);
    std::cin.ignore(10000, '\n');
    std::cin.ignore(10000, '\n');
    return EXIT_SUCCESS;

}
 

As a server address, I use my local host: 127.0.0.1

How can I modify them so that the server can send messages to the client?

Thank you respectfuly.

P.S. Please excuse my english, I'm not a native speaker.