Software

In the recent interview with InformIT, Donald Knuth said:

I also must confess to a strong bias against the fashion for reusable code. To me, "re-editable code" is much, much better than an untouchable black box or toolkit. I could go on and on about this. If you’re totally convinced that reusable code is wonderful, I probably won’t be able to sway you anyway, but you’ll never convince me that reusable code isn’t mostly a menace.

I have tried in vain to locate any place where he talks about this topic at greater length. Does anyone have a link?

Every so often, I come across some utility that need. I think it must have been written before, but I can't find it.

Today I needed a tool to take a set of files and split them up into directories in a size that will fit on DVDs. I wanted a tool that could either produce the minimum number of DVDs, or keep the files in order. I couldn't find one. So I wrote datapacker.

datapacker is a tool to group files by size. It is perhaps most often used to fit a set of files onto the minimum number of CDs or DVDs.

datapacker is designed to group files such that they fill fixed-size containers (called "bins") using the minimum number of containers. This is useful, for instance, if you want to archive a number of files to CD or DVD, and want to organize them such that you use the minimum possible number of CDs or DVDs.

In many cases, datapacker executes almost instantaneously. Of particular note, the hardlink action can be used to effectively copy data into bins without having to actually copy the data at all.

datapacker is a tool in the traditional Unix style; it can be used in pipes and call other tools.

I have, of course, uploaded it to sid. But while it sits in NEW, you can download the source tarball (with debian/ directory) from the project homepage at http://software.complete.org/datapacker. I've also got an HTML version of the manpage online, so you can see all the cool features of datapacker. It works nicely with find, xargs, mkisofs, and any other Unixy pipe-friendly program.

Those of you that know me will not be surprised that I wrote datapacker in Haskell. For this project, I added a bin-packing module and support for parsing inputs like 1.5g to MissingH. So everyone else that needs to do that sort of thing can now use library functions for it.

Update... I should have mentioned the really cool thing about this. After datapacker compiled and ran, I had only one mistake that was not caught by the Haskell compiler: I said < where I should have said <= one place. This is one of the very nice things about Haskell: the language lends itself to compilers that can catch so much. It's not that I'm a perfect programmer, just that my compiler is pretty crafty.