How can I set the exit code from return code of my Execute File in Inno Setup?

Question

I want to get return code (negative value) from my {app}\{#MyAppExeName} for setup exit code (MyAppExeName will run 20~30s)

I refer many example codes, and Exec can get result code but still don't know how to add to [Code] section for setup exit code (I have no idea about Pascal Script)

Below is [Run] section in my Inno Setup Script

[Run]
Filename: "{app}\{#MyAppExeName}"; Description: "{cm:LaunchProgram,{#StringChange(MyAppName, '&', '&&')}}"; Flags: nowait postinstall skipifsilent

How to change [Run] & [Code] section for my goal?

Please help me and give me example code

Thanks

BR, Alan

Answer 1

To run an external process and retrieve its exit code, using Exec support function.

To modify installer's exit code, implement GetCustomSetupExitCode event function

[Code]

var
  ExitCode: Integer;
  
procedure CurStepChanged(CurStep: TSetupStep);
begin
  if CurStep = ssPostInstall then
  begin
    if Exec(
         ExpandConstant('{app}\{#MyAppExeName}'), '', '', SW_SHOW,
         ewWaitUntilTerminated, ExitCode) then
    begin
      Log(Format('Command finished, exit code is %d', [ExitCode]));
    end
      else
    begin
      Log('Failed to run command');
    end;
  end;
end;

function GetCustomSetupExitCode: Integer;
begin
  if ExitCode <> 0 then
  begin
    Log(Format('Returning exit code %d', [ExitCode]));
  end;
  Result := ExitCode;
end;

---

Note that Windows process exit code cannot be negative. The exit code is an unsigned 32-bit integer.

See how uExitCode parameter of ExitProcess and well as lpExitCode parameter of GetExitCodeProcess are of UINT and DWORD types respectively.

It's just a common error/misconception that the exit code is interpreted as signed.

The Inno Setup follows that misconception by using signed integer value in GetCustomSetupExitCode.