Mac OS X Leopard - ARCAism

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CHAPTER 19 EXTENDING THE POWER OF DARWIN
use the irb command). For OS X developers the most important similarity is that they are both
compiled as Cocoa frameworks, which makes them available for Cocoa development as well as
Darwin development. Despite the similarities, Ruby is different from Python most noticeably
semantically but also syntactically.
Because Ruby is a newer language, it seems to have learned to avoid a number of issues and
perhaps shortcomings that Perl and Python have had, while at the same time incorporating new
ideas that weren’t mature when Perl and Python were conceived. On the other hand, because of
its relative newness, Ruby has not been tested as much as Perl or Python and as such may not be
as hardened as them. For example, there are those who think Ruby does not scale (in a performance
sense) as well as Perl or Python.
NOTE Much of the performance talk about Ruby may stem from the fact that nobody has
actually used Ruby on a massively large scale. Ultimately, as a new language evolves, it will be
tested, and in certain areas, it will fail or perform poorly; however, as it grows, those issues will
be resolved. Ruby seems to be hovering around those last performance hurdles, but we won’t
know whether it’s actually there until someone does something with it. Python may be considered
the most scalable scripting language today, but it wasn’t considered that until people
realized just how much it could handle (a large amount of Goggle’s back end allegedly runs on
Python, which one would assume puts the question of Python’s scalability to rest).
We’ll be looking at Ruby, specifically Ruby on Rails, a framework for web development,
later in this book. To learn more about Ruby in general, check out Beginning Ruby by Peter
Cooper (Apress, ISBN: 1590597664). If you are looking for specifics on Developing Ruby
Cocoa applications, documentation is included with the Xcode Tools installation (/Developer/
Documentation/RubyCocoa/).
Installing New Darwin Software
Although scripting is a good solution for simple problems, or new problems, often it’s easier to
just use a program that someone else has already written. Since Unix and related operating systems
(such as Linux) have been around for a very long time and continue to be popular, for many
of the tasks you may want to accomplish, an existing application or program may already be
available. Best of all, many of these programs are available for free and are waiting for you to
install them. Some are available simply by downloading an OS X installation package and
installing them like any other OS X app (MySQL is a popular database that is available in many
formats, including an official OS X installation package), but many more are available either as
a precompiled binary (that is, a ready-to-run program) or more commonly (and often preferably)
as a source package. This gives you some options; you could download the source package, configure
it for your specific needs, and then compile the source code into an application optimized
for your computer. You could try to locate a precompiled binary and install that (and hope that
it works right). Or you could take advantage of either Fink or MacPorts (formally known as
DarwinPorts), which are two systems of finding, installing, and maintaining third-party Darwin
applications. This ultimately boils down to preference, but if you haven’t already formed your
own, we suggest you try things in this order:
1. An official binary release, if available, would be the first choice. This should make
installation trivial and effective and should make for easy upgrades if needed. Additionally,
any other applications that may rely on the application would probably assume the official
release.