Pascal (Lazarus/Delphi)

Accept Connection on Socket

See more Socket/SSL/TLS Examples

Demonstrates how to create a TCP/IP socket, listen on a port, accept an incoming connection, and send a "Hello World" message to the client. Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Socket;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  listenSocket: TSocket;
  connectedSocket: TSocket;

begin
  success := False;

  //  This example requires the Chilkat API to have been previously unlocked.
  //  See Global Unlock Sample for sample code.

  listenSocket := TSocket.Create;

  //  Bind to a port and listen for incoming connections:
  //  This example will listen at port 5555 and allows for a backlog
  //  of 25 pending connection requests.
  success := listenSocket.BindAndListen(5555,25);
  if (success = False) then
    begin
      WriteLn(listenSocket.LastErrorText);
      Exit;
    end;

  //  Get the next incoming connection
  //  Wait a maximum of 20 seconds (20000 millisec)
  connectedSocket := TSocket.Create;
  success := listenSocket.AcceptNext(20000,connectedSocket);
  if (success = False) then
    begin
      WriteLn(listenSocket.LastErrorText);
      Exit;
    end;

  //  Set maximum timeouts for reading an writing (in millisec)
  connectedSocket.MaxReadIdleMs := 10000;
  connectedSocket.MaxSendIdleMs := 10000;

  //  Send a "Hello World!" message to the client:
  success := connectedSocket.SendString('Hello World!');
  if (success <> True) then
    begin
      WriteLn(connectedSocket.LastErrorText);
      Exit;
    end;

  //  Close the connection with the client.
  //  Wait a max of 20 seconds (20000 millsec)
  success := connectedSocket.Close(20000);

  WriteLn('success!');


  listenSocket.Free;
  connectedSocket.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.