Display directory from delphi - windows

Question

I would like to display the contents of a directory using DOS commands from Delphi(7). Using Win10 - 64
The following program displays the DOS shell but does not display the directory contents. What is wrong with my code ?
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, shellapi;
type
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.FormCreate(Sender: TObject);
var i : integer;
begin
i := ShellExecute(Handle, nil, 'cmd.exe', PChar(' dir'), nil, SW_SHOW);
caption := inttostr(i);
end;
end.

Answer 1

Running your code on Windows 10 returns 2, which is ERROR_FILE_NOT_FOUND.
I got it to work, on both 32- and 64-bit target platforms, by changing it to
this:
var
ComSpec: string;
retval: HINSTANCE;
begin
ComSpec := GetEnvironmentVariable('comspec');
retval := ShellExecute(Handle, nil, PChar(comspec), '/k dir', nil, SW_SHOW);
if retval <= 32 then
Caption := Format('Error, return value = %d', [retval])
else
Caption := 'Success';
end;
The /k says to run a new instance of cmd.exe and keep the window open. For more details, run cmd /? from a command prompt.
Note that the error handling of ShellExecute is very limited. If you wish to check for errors comprehensively then you must use ShellExecuteEx instead.