Changing win32 icons from a Mac with Perl

The current build procedure for Talking Panda involves taking two stub applications (Mac OS X, Win2K/XP) and replacing their resources. This is extremely easy for the Mac installer, because it's just a bunch of folders. It's actually so convenient that I use the Mac application bundle to house the majority of resources that the Windows installer uses. Unfortunately, I do have to change one in-exe resource for the Win32 installer: the application's icon.

The Win32 application icons are still created "by hand" using Axialis IconWorkshop, which I highly recommend. It understands the Mac OS X icns format and does everything in a few shortcut keystrokes. Eventually I hope to write a script to generate the Windows icons on the fly with PIL, but I had a bit of trouble trying to find updated specs for the Windows XP additions to the ICO format.

I did some research into the Microsoft Portable Executable File Format, but was unable to find any portable C or Python libraries that could create a new executable using an existing one as a template. py2exe does this, but it uses a non-portable C library. Whenever this happens, I generally turn to Perl. CPAN is pretty good about having modules to read/write various file formats (the only other Perl I've used in the past few years is for reading/writing Excel spreadsheets).

Unsurprisingly, CPAN did indeed have what I needed in a module called Win32::Exe, which has a pretty painless API. And here it is, my most recent Perl monstrosity. It takes 3 arguments, the source executable, the new icon, and the destination executable. If someone wrote an equivalent Python module, I'd love to switch, but this does the job quite nicely for now.

#!/usr/bin/perl

use Win32::Exe;
use strict;
my $exe = Win32::Exe->new(shift());
$exe->update(icon => shift());
$exe->write(shift());