I've been playing around with the debian-cd package recently for ProLinux, turns out the Debian build process is a little antiquated and written for the larger part in Perl.
As a result (mainly of the latter), I'm in the process of re-writing the entire procedure in Python and have come across many optimisations, but the biggest revelation is a package called python-apt. Previously I'd see the python dpkg tools package, but python-apt is a new one on me - and it's very handy.
Consider the question; "I'd love to know which package installed 'that' file" or more to the point, "which packages contain 'that' file", here's a very easy answer.
#!/usr/bin/python3 import apt,sys db = apt.cache.Cache() for pkg in db.keys(): words = pkg.split(":") try: package = db[words] for item in package.installed_files: words = item.split("/") if sys.argv in words: print(pkg,item) except: pass
If you run this and pass say "xterm.faq.gz" as a parameter, you'll get something like this;
# ./what.py xterm.faq.gz xterm /usr/share/doc/xterm/xterm.faq.gz xterm:i386 /usr/share/doc/xterm/xterm.faq.gz
You can do lots of other cool things with dependencies etc, but ultimately it condenses the install process into a couple hundred lines of Python and all the Makefiles, Perl and Bash go out the window.
It seems you can get a Python package to do pretty mich anything for you .. although I'm still looking for the python-coffee package .. maybe one day ...