Compiling Perl Scripts into Standalone Executables

This tutorial outlines the steps you need to take in order to compile your perl scripts into standalone executables. There are a few ways to do this, including the commerical Perl2Exe, and packages such as PerlBin and App::Packer, and a tool called perlcc. I have had the most luck using a free perl module called PAR, which packs perl code into a single .exe file, including all DLLs and other dependencies, so that is what I will discuss here. It is a very reliable and powerful tool, and has not disappointed me yet (which I cannot say for its alternatives). Please keep in mind as you read this that there is a reason people still code in C++ instead of just using 'compiled' perl. This is a fun (and useful!) trick, but if you're making a widely-distributed application, you should ask yourself if perl is really the correct language to use.

Why would you want to do this? Often, people wish to obscure their perl code by 'compiling' it. Unfortunately (or perhaps, fortunately, depending on your point of view), it is possible to 'decompile' executables made from perl code and look at the original source. Of course, compiling does add a layer of defense, and additional source-obscuring techniques are available through PAR (see the -f option in the pp documentation below), but this by no means keeps a determined and savvy individual from looking at your source code.

Another reason to 'compile' perl source code is to make the code run faster. Note that the actual instructions are executed no faster in a 'compiled' executable than in the original script: all that this process does is bundle everything you need to run the script together in one zip file (even though it 'looks' like an .exe). You do eliminate the need to recompile the script each time it is run, but the first time it is executed, there may be some delay while the archive is decompressed (the following executions should not have a delay -- the first time the script is run, the files are unpacked into your temporary directory so that they can be used again later).

The 'real' reason to want to compile perl code into an executable is portability. Imagine you've written a killer perl script that you want to give to your friend, but in order to use it, he has to install new modules, and maybe even upgrade his version of perl. Or even better, what about that friend you have who doesn't even have perl, and has no idea how to install it. Compiling perl scripts allows you to create applications that anyone can use without a hassle. In fact, you can even write scripts using Perl/Tk along with the compiler, to make full-featured applications with GUIs.

First, you will have to extract the files from the tarred, gzipped files you downloaded from CPAN. If you don't already have a utility to do this, I recommend 7-Zip -- it's great compression utility, and it's free. If you are using 7-Zip, simply right click on the archived files and select "extract files".

Once you have extracted the archived files, you will have three folders (one for each module). Open up a DOS command window (Start->Run and enter Cmd on Windows XP or command on Windows 98), and do the following steps for each of the modules. Make sure you install the modules in the order in which they appear in the list in section 2.

First, navigate to the folder containing the module files (using the cd command). Next, type the following commands and wait for each to execute:

perl Makefile.pl
nmake
nmake test
nmake install

Note: You may get some error messages when running the make test and make install commands for PAR. To be honest, I am not quite sure why these pop up, but everything seems to work fine with the modules on my machine, so I haven't worried about it too much.