How should I distribute a pre-built perl module, and what version of perl do I build for?

Question

This is probably a multi-part question. Background: we have a native (c++) library that is part of our application and we have managed to use SWIG to generate a perl wrapper for this library. We'd now like to distribute this perl module as part of our application.

My first question - how should I distribute this module? Is there a standard way to package pre-built perl modules? I know there is ppm for the ActiveState distro, but I also need to distribute this for linux systems. I'm not even sure what files are required to distribute, but I'm guessing it's the pm and so files, at a minimum.

My next question - it looks like I might need to build my module project for each version of perl that I want to support. How do I know which perl versions I should build for? Are there any standard guidelines... or better yet, a way to build a package that will work with multiple versions of perl?

Sorry if my questions make no sense - I'm fairly new to the compiled module aspects of perl.

CLARIFICATION: the underlying compiled source is proprietary (closed source), so I can't just ship source code and the appropriate make artifacts for the package. Wish I could, but it's not going to happen in this case. Thus, I need a sane scheme for packaging prebuilt binary files for my module.

Answer 1

DISCLAIMER: I have next to no experience creating binary packages that can easily be installed. Therefore, I am making this post CW to make it easier for others to add their advice.

You should make the distribution available in source form so it can be compiled on each system tailored according to the specifics of that system. I really like Module::Build for that purpose.

For ActiveState users on Windows, you probably want to have four or six PPMs based on whether you want to support 5.6. Package both 32-bit and 64-bit versions for each of 5.6, 5.8 and 5.10. Use the version of mingw you can install using ppm to compile the modules to preserve binary compatibility.

Another option is to use PAR::Packer and distribute your application in a PAR archive. In that context, PAR::WebStart might be useful although I have not tried it. I have had success with PAR archives in the past, though.

Answer 2

I look after DBD::Informix, one of the Perl Database Driver modules that works with the DBI (Perl Database Interface). The underlying libraries used to connect to IBM Informix Dynamic Server (IDS) are proprietary, but the DBD::Informix code itself is not. I distribute that code on CPAN, just the same as any other Perl module. People can download that source, and (provided that they have the Informix ClientSDK installed on their machine - and Perl and DBI and so on), they can build DBD::Informix to work with their installed Perl.

I would strongly counsel that you arrange that your Perl interface code be made available in source form, even though the library that it interfaces to is proprietary. This allows people to install the code with any version of Perl they have - without requiring you to deal with inconsistencies.

If you still want to provide binary support, you are going to have to work out which platforms you want to support, and build the module with the standard version of Perl on each such platform. This gets messy. You need access to an instance of each machine. Granted, virtual machines make this easier, but it is still fiddly and the number of platforms and versions only grows. But you still need to support people who don't use the standard version of Perl on their machine - that's why the Perl wrapper interface needs to be provided in source form.