Easier said than done! First I had to get the entire developer kit (2+ Gb of downloads, and a couple of hours to install) from Apple. (I can see excluding the GUI developer tools, XCode and friends, from a default OS X install—but why the command-line C compiler and a basic set of libraries and header files? They'd take up a negligible amount of disk space.)
Next came installing the actual SDL libraries, then the Perl-to-SDL interface. I first tried Fink, which aims to provide one-stop shopping for .deb packages à la the various GUI frontends to apt in different Linux distros. Fink presents you with a window of available packages (which updates every time you open it, naturally) and downloads the ones you choose either as an OS X binary if one exists or as source if necessary (then configuring the latter to build under Darwin, compiling it, etc.). Fink has worked well for me in the past, but in this case though the list of available packages included SDL, it didn't include SDL-Perl. Fine, I thought, I'll tell Fink to install SDL, then install SDL-Perl via the command-line CPAN installer module included with Perl. The former worked OK; the latter didn't. The CPAN installer module couldn't deal with the many modules that were prerequisites to installing SDL-Perl, so I gave up and started doing everything by hand. This quickly led me into a "dependency hell" wherein every tarball I downloaded seemed to require that something else already be installed. About here is when I started to feel like banging my head against the keyboard. THIS SHOULDN'T HAPPEN. The problem of package dependencies on Unix-like systems was solved 15 years ago when the first Debian Linux distribution was released. I remember installing Debian 1.something on my first Linux box, which had previously been running Red Hat with its markedly inferior .rpm package system, and marvelling at how smoothly the install process went despite my idiosyncratic selection of software from the packages available.
Then I tried MacPorts, a similar front end to open-source software, mostly command-line and X Window stuff configured for Darwin. After installing it from a .pkg file (a self-installing Mac OS X package format) I typed just one line in a terminal window (MacPorts so far has no GUI front end):
sudo port install p5-sdl_perland was rewarded with a couple of hundred lines of beee-you-dee-ful status info scrolling by; extracting this, checksumming that, and compiling the other thing, as MacPorts automagically set up the necessary prerequisites and finally SDL-Perl itself. When I tried to run my Perl script again, it Just Worked.1,2
Moral: No matter whether your software is the most user-friendly GUI application ever, or some kind of arcane tool only to be used by superhackers; if you don't implement (at the very least) dependency checking or (preferably) automatic dependency resolution, you deserve forty lashes with a wet noodle, as Ann Landers used to say.
- Well, almost—I had to tell Perl where to find the new modules, but that was both trivial and something I needed to know how to do anyway. [back]
- Check it out! (Not impressed yet? Hey, it's just proof of concept.) [back]