How to get Inno Setup to unzip a file it installed (all as part of the one installation process)

Question

To save bandwidth/space as well as prevent accidental meddling, the installation files for a database product (call it Ajax), have been zipped up (call that file "AJAX_Install_Files.ZIP). I would like to have Inno-Setup "install" (i.e., copy) the AJAX_Install_Files.ZIP file to the destination, and then Unzip the files into the same folder where the .ZIP file is located. A subsequent program would be fired off by Inno Setup to actually run the install of product "Ajax".

I've looked through the documentation, FAQ, and KB at the Inno Setup website, and this does not seem possible other than writing a Pascal script (code) - would that be correct, or are there are any alternative solutions?

Answer 1

You can use an external command line tool for unzipping your archive, see here for example. Put it in your [Files] section:

[Files]
Source: "UNZIP.EXE"; DestDir: "{tmp}"; Flags: deleteafterinstall

Then call it in your [Run] section, like this:

[Run]
Filename: "{tmp}\UNZIP.EXE"; Parameters: "{tmp}\ZipFile.ZIP -d C:\TargetDir"

(You'll probably want to take your target directory from a script variable, so there is some more work that needs to be done)

Answer 2

You can use the shell Folder.CopyHere method to extract a ZIP.

const
  SHCONTCH_NOPROGRESSBOX = 4;
  SHCONTCH_RESPONDYESTOALL = 16;

procedure UnZip(ZipPath, TargetPath: string); 
var
  Shell: Variant;
  ZipFile: Variant;
  TargetFolder: Variant;
begin
  Shell := CreateOleObject('Shell.Application');

  ZipFile := Shell.NameSpace(ZipPath);
  if VarIsClear(ZipFile) then
    RaiseException(
      Format('ZIP file "%s" does not exist or cannot be opened', [ZipPath]));

  TargetFolder := Shell.NameSpace(TargetPath);
  if VarIsClear(TargetFolder) then
    RaiseException(Format('Target path "%s" does not exist', [TargetPath]));

  TargetFolder.CopyHere(
    ZipFile.Items, SHCONTCH_NOPROGRESSBOX or SHCONTCH_RESPONDYESTOALL);
end;

Note that the flags SHCONTCH_NOPROGRESSBOX and SHCONTCH_RESPONDYESTOALL work on Windows Vista and newer.

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For an example of extracting some files only, see:
How to get Inno Setup to unzip a single file?