Inno Setup Code section create hidden file

Question

I am working with an Inno Setup project. The project is writing a file out using the SaveStringToFile function in the [Code] section. I would like to make this file a hidden system file, but I haven't been able to find information on how to make this work. Any ideas?

Answer 1

There is no function to set file attributes in Inno Setup Pascal Script. So either you would have to import Windows API functions that can set file attributes or use the following trick. You can create an empty file which you'll set to be hidden in the script entry and after that you can write whatever you need there, so it will be the installation process which will create a hidden file for you:

[Files]
; MyFile.txt is an empty text file
Source: "MyFile.txt"; DestDir: "{app}"; Attribs: hidden; AfterInstall: WriteToFile

[Code]
procedure WriteToFile;
begin
  SaveStringToFile(ExpandConstant('{app}\MyFile.txt'), 'Hello!', True);
end;

For the sake of completeness I'm including also a function by which you can explicitly set hidden attribute to a file:

[Code]
#ifdef UNICODE
  #define AW "W"
#else
  #define AW "A"
#endif

const
  INVALID_FILE_ATTRIBUTES = $FFFFFFFF;

function GetFileAttributes(lpFileName: string): DWORD;
  external 'GetFileAttributes{#AW}@kernel32.dll stdcall';
function SetFileAttributes(lpFileName: string; dwFileAttributes: DWORD): BOOL;
  external 'SetFileAttributes{#AW}@kernel32.dll stdcall';

procedure RaiseLastOSError;
var
  LastError: LongInt;
begin
  LastError := DLLGetLastError;
  RaiseException(Format('System Error. Code: %d. %s', [LastError,
    SysErrorMessage(LastError)]));
end;

procedure SetFileHiddenAttr(const FileName: string);
var
  Attrs: DWORD;
begin
  Attrs := GetFileAttributes(FileName);
  if Attrs <> INVALID_FILE_ATTRIBUTES then
  begin
    if Attrs and FILE_ATTRIBUTE_HIDDEN = 0 then
      if not SetFileAttributes(FileName, Attrs or FILE_ATTRIBUTE_HIDDEN) then
        RaiseLastOSError;
  end
  else
    RaiseLastOSError;
end;