Send text messages between two computers through internet with delphi?

Establishing direct text communication between two computers over the internet with Delphi involves several steps:

1. Network Configuration:
2. Ensure that both computers are connected to the same network and have properly configured IP addresses.
3. If using a peer-to-peer network, configure port forwarding on the router to allow incoming connections to the computers' ports.
4. Centralized Server:
5. Set up a PHP script on a web server to act as a centralized server for coordinating communication between the clients.
6. The script should handle tasks like client registration, message routing, and maintaining a list of active clients.
7. Indy Socket Library:
8. Utilize the Indy socket library in Delphi to handle actual text communication between the computers.
9. The Indy library provides components and classes for creating socket-based applications, enabling data exchange over the network.
10. Client-Server Communication:
11. Develop a client application using Delphi that connects to the centralized server, registers its presence, and waits for messages from other clients.
12. Create a server application that listens for incoming connections from clients, receives messages, and forwards them to the appropriate recipients.

Here's an example using Delphi's Indy library for basic client-server text communication:

```delphi // Client code procedure TForm1.btnConnectClick(Sender: TObject); begin // Connect to the server IdTCPClient1.Host := '127.0.0.1'; // Server IP address IdTCPClient1.Port := 8080; // Server port IdTCPClient1.Connect; end; procedure TForm1.IdTCPClient1DataArrival(Sender: TObject; const Buffer: Pointer; BytesReceived: Integer); begin // Handle incoming messages from the server ShowMessage(IdTCPClient1.ReceiveText); end; // Server code procedure TForm2.btnStartServerClick(Sender: TObject); begin // Start listening for client connections IdTCPServer1.Port := 8080; // Server port IdTCPServer1.Active := True; end; procedure TForm2.IdTCPServer1ClientConnect(Sender: TObject; AClient: TIdTCPConnection); begin // Handle new client connections AClient.Connected := True; end; procedure TForm2.IdTCPServer1ClientDisconnect(Sender: TObject; AClient: TIdTCPConnection); begin // Handle client disconnections AClient.Connected := False; end; procedure TForm2.IdTCPServer1Execute(Sender: TObject); begin // Send a message to the client Sender.Connection.Socket.SendText('Hello from the server!'); end; ```

This basic example demonstrates how to establish a client-server connection and send text messages between the computers using Delphi's Indy library.