Pascal (Lazarus/Delphi)

HTTP HEAD Request

See more HTTP Examples

Sends an HTTP HEAD request and gets the response.

Note: The response to an HTTP HEAD request is always just the response header. The reponse body is always 0 length (thus the reason it's called a "HEAD" request..)

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.HttpResponse,
  Chilkat.Http;

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

procedure RunDemo;
var
  success: Boolean;
  http: THttp;
  resp: THttpResponse;
  numHeaderFields: Integer;
  i: Integer;

begin
  success := False;

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

  http := THttp.Create;

  //  If the URL uses "https://", then the connection will be TLS.
  //  Otherwise it will be TCP.

  //  A failure is when we don't get any response.  It could be a timeout, an inability to connect, etc.
  //  For example, a "404 Not Found" response is still a response, and thus deemed success in terms of the API..

  resp := THttpResponse.Create;
  success := http.HttpNoBody('HEAD','https://example-code.com/',resp);
  if (success = False) then
    begin
      WriteLn(http.LastErrorText);
      Exit;
    end;

  //  Examine the response.
  WriteLn('Status Code = ' + resp.StatusCode);
  WriteLn('Status Line = ' + resp.StatusLine);
  WriteLn('Status Text = ' + resp.StatusText);
  WriteLn('Full Response Header:');
  WriteLn(resp.Header);
  WriteLn('----');
  numHeaderFields := resp.NumHeaderFields;
  WriteLn('Num Header Fields: ' + numHeaderFields);

  for i := 0 to numHeaderFields - 1 do
    begin
      WriteLn(resp.GetHeaderName(i) + ': ' + resp.GetHeaderValue(i));
    end;



  http.Free;
  resp.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.