Bind and Listen for Incoming Connections

See more Socket/SSL/TLS Examples

Demonstrates Socket.BindAndListen, which binds a TCP listener to a port and places it into listening mode, then accepts an incoming connection.

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;
  socket: TSocket;
  connectedSock: TSocket;

begin
  success := False;

  socket := TSocket.Create;

  //  Bind a TCP listener to a port and place it into listening mode.  The 2nd argument is the backlog,
  //  the maximum number of pending connections allowed to queue.
  success := socket.BindAndListen(5000,25);
  if (success = False) then
    begin
      WriteLn(socket.LastErrorText);
      Exit;
    end;

  //  After the listener is established, accept the next incoming connection into a new Socket.
  connectedSock := TSocket.Create;
  success := socket.AcceptNext(20000,connectedSock);
  if (success = False) then
    begin
      WriteLn(socket.LastErrorText);
      Exit;
    end;
  WriteLn('Accepted a connection.');


  socket.Free;
  connectedSock.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.