README

depfinder is a tool that finds the dependencies of Slackware packages.

depfinder is much faster than requiredbuilder, a very nice script
by Stefano Stabellini that I used in the past to find package
dependencies. But requiredbuilder is written entirely in bash and I
had always thought that optimizing the search routines in C or C++
would make the whole process a lot faster. So, the speed difference
mainly comes from the C++ code that is used in depfinder to find in
which package each individual library is included. That C++ code is
'borrowed' (as in blatanly ripped) from Nigel Bosch's zpm code.

depfinder also has support for running multiple jobs in parallel that
makes it a lot faster when used with multiple CPUs/cores.

The dependency list is by default being output in a comma separated
list, without version information, but there are options to output
dependencies with version information and to a file: a .dep file
with a comma separated list without version information, or a
slack-required file with version information, respectively.

Note that I don't really agree with version information in
dependency lists. "libxyz >= 1.0-i486-2gv" actually doesn't always
mean that the package will work with any version of libxyz greater
than 1.0. There will be cases that it will have to be rebuilt with
a new libxyz version. Also the check will fail if someone has
"libxyz >= 1.0-i486-1xy" installed since "1xy"<"2gv". But the two
libxyz packages might really be identical otherwise. Using
"libxyz = 1.0-i486-2gv" is not a solution, since the check will
always fail with any subsequent libxyz packages, prompting for
a package rebuild, which would be completely unnecessary. But this is
the format used as standard for slack-required files that are used by
many slackware-based projects, so I added support for it anyway.

I also don't personally agree with slack-required files being
inside packages, which I think is a very poor and inefficient design.
A simple change in the dependency list, which would otherwise require
the editing of a text file only, requires rebuilding the package, which
then requires reuploading and redistributing the package, for the users
only to upgrade to a version that in terms of functionality is identical
to the one they have with the previously installed package. Lots of
work, time and bandwidth can be completely wasted that way.
But that's really a whole different matter and I'll stop my ranting
now, since everyone can do whatever he wants with the dependency list
he gets with depfinder.

depfinder is perfectly accurate when detecting dependencies of binary
files. I didn't want to implement support for detecting python
dependencies until I was sure I could do it in a way that would really
work. I didn't want to go the way requiredbuilder went and "pretend" to
have support for detecting python dependencies. Detecting python as a
dependency and detecting python dependencies is not at all the same
thing. The way it works now in depfinder I think is the best way it can
be done. All python files in a package are parsed for modules that they
import (or try to import). In most cases there is going to be some extra
output in the form of warnings and the packager might need to do some
manual work to sort out which python dependencies are optional and which
are not, but at least there is no chance that a python dependency will
not be reported (I think). Python dependency checking is going to make
depfinder run a bit slower, it needs to do a lot of work, probing every
single file in the package and parsing all python scripts for certain
keywords, but it's not really that bad in terms of speed. Support for
detecting perl dependencies might be a possibility for the future.

Apart from basic shell commands, like ls, sed, touch etc, depfinder
requires python in order to detect python dependencies. You also need to
have the gcc-g++ compiler, so that depfinder-search can be compiled.

A huge thanks goes to Nigel Bosch for creating the original code for his
zpm package manager and making it available in the first place.