yum vs. apt

[James Wilkinson]

Ralf Corsepius wrote:
> Furthermore, yum is a script-based application suffering from the same
> deficiencies all script-based applications suffer from. 

Erik Hemdal asked:
> What deficiencies are you thinking about?

and Ralf replied:
> Basically, I was thinking about package dependencies, because it's very
> easy to break script-based applications by corrupting the interpreter
> underneath, than it is to break a binary application.
> 
> Problems like this
> http://www.redhat.com/archives/fedora-devel-list/2004-November/msg01218.html
> are typical for script-based applications.

(Yum in Rawhide is currently broken due to a broken development version
of Python).

I'm not particularly sure this supports what you're arguing, Ralf. It
looks like you're arguing against using libraries.

I'd say it shows that packages with dependencies may break if the
dependencies break. One might assume that, all else being equal,
packages with more dependencies are more likely to break due to bad
dependencies.

And one might argue that generally, a script in a scripting language has
scripting language + glibc + libraries for dependencies whereas a
compiled C program will have glibc + libraries.

But I don't think all is equal. The scripting languages themselves tend
to be pretty stable. More importantly, writing in a higher-level
interpreted language means that there's more support for run-time
checking (so programs fail noisily and get fixed rather than appear to
run and corrupt stuff), and they do more stuff for you (so you rely on
existing, debugged, language support rather than program-specific code).

And generally, the wisdom seems to be not "put your eggs in many
baskets", and re-implement the same routines for each package, but "put
your eggs in one basket, and *watch* *that* *basket*": put your library
routines in a library, and make sure it's debugged.

So with scripting languages, even if one does get more breakages due to
dependencies, one is likely to get less due to the program itself being
broken. I'd say you get less overall.

And then of course you shouldn't get buffer over-runs in scripts...

James.
-- 
E-mail address: james | Never ask, "Oh, why were things so much better
@westexe.demon.co.uk  | in the old days?"
                      | It's not an intelligent question.
                      |     -- Ecclesiastes 7 v. 10