Shlomi Fish (shlomifish) wrote,
Shlomi Fish

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Sherlock Holmes about the Awk Programming Language

I enjoyed reading some of Sir Arthur Conan Doyle’s writings about the fictional detective Sherlock Holmes when I was younger, which were entertaining (although possibly distanced from the way actual crime investigation actually works), and interesting. I vividly recall one excerpt from the very first Sherlock Holmes story A Study in Scarlet:

His ignorance was as remarkable as his knowledge. Of contemporary literature, philosophy and politics he appeared to know next to nothing. Upon my quoting Thomas Carlyle, he enquired in the naivest way who he might be and what he had done. My surprise reached a climax, however, when I found incidentally that he was ignorant of the Copernican Theory and of the composition of the Solar System. That any civilized human being in this nineteenth century should not be aware that the earth travelled round the sun appeared to be to me such an extraordinary fact that I could hardly realize it.

"You appear to be astonished," he said, smiling at my expression of surprise. "Now that I do know it I shall do my best to forget it."

"To forget it!"

"You see," he explained, "I consider that a man's brain originally is like a little empty attic, and you have to stock it with such furniture as you choose. A fool takes in all the lumber of every sort that he comes across, so that the knowledge which might be useful to him gets crowded out, or at best is jumbled up with a lot of other things, so that he has a difficulty in laying his hands upon it. Now the skilful workman is very careful indeed as to what he takes into his brain attic. He will have nothing but the tools which may help him in doing his work, but of these he has a large assortment, and all in the most perfect order. It is a mistake to think that that little room has elastic walls and can distend to any extent. Depend upon it there comes a time when for every addition of knowledge you forget something that you knew before. It is of the highest importance, therefore, not to have useless facts elbowing out the useful ones."

"But the Solar System!" I protested.

"What the deuce is it to me?" he interrupted impatiently; "you say that we go round the sun. If we went round the moon it would not make a pennyworth of difference to me or to my work."

(Chapter 2 of A Study in Scarlet by Sir Arthur Conan Doyle, under the public domain in most countries.)

Conan Doyle was naturally exaggerating here in portraying the ideal of Sherlock Holmes (as few, if any, human beings can forget that the Earth revolves around the Sun), but the principle still stands: we need to make a conscious decision of how to manage our memory, because there is a limit to how many different aspects can put inside our resident memory, or otherwise we'll forget more important stuff.

So what does it has to do with the Awk programming language? Many decades after A Study in Scarlet, Eric S. Raymond had this to say in his book The Art of Unix Programming:

A case study of awk is included to point out that it is not a model for emulation; in fact, since 1990 it has largely fallen out of use. It has been superseded by new-school scripting languages—notably Perl, which was explicitly designed to be an awk killer. The reasons are worthy of examination, because they constitute a bit of a cautionary tale for minilanguage designers.

The awk language was originally designed to be a small, expressive special-purpose language for report generation. Unfortunately, it turns out to have been designed at a bad spot on the complexity-vs.-power curve. The action language is noncompact, but the pattern-driven framework it sits inside keeps it from being generally applicable — that's the worst of both worlds. And the new-school scripting languages can do anything awk can; their equivalent programs are usually just as readable, if not more so.

For a few years after the release of Perl in 1987, awk remained competitive simply because it had a smaller, faster implementation. But as the cost of compute cycles and memory dropped, the economic reasons for favoring a special-purpose language that was relatively thrifty with both lost their force. Programmers increasingly chose to do awklike things with Perl or (later) Python, rather than keep two different scripting languages in their heads.[90] By the year 2000 awk had become little more than a memory for most old-school Unix hackers, and not a particularly nostalgic one.

Falling costs have changed the tradeoffs in minilanguage design. Restricting your design's capabilities to buy compactness may still be a good idea, but doing so to economize on machine resources is a bad one. Machine resources get cheaper over time, but space in programmers' heads only gets more expensive. Modern minilanguages can either be general but noncompact, or specialized but very compact; specialized but noncompact simply won't compete.

(Emphasis mine.)

(Case Study: awk in minilanguages in The Art of Unix Programming by Eric Steven Raymond, text available under the Creative Commons Attribution-NonDerivatives licence, and hopefully quoted here (with attribution) under fair use auspices.)

Back in 1996, after I first learned Perl and started working on Unix, I asked one of my co-workers if I should learn Awk and he said “Forget it! Perl can do everything Awk does and more, and is a much better language”. (That was some time before other of the so-called “scripting languages” that gained popularity after Perl, were notable and/or mature enough to be considered by most sane people.) While I was not entirely convinced, and also ended up using GNU awk (gawk) to write a small text processing script for Microsoft Windows at one point (because I preferred not to investigate how to make the perl executable more self-contained). For a while, I felt guilty about not being fluent in Awk, until I read what Raymond said, when I realised why he, my co-worker, and Conan Doyle’s words of Sherlock Holmes, have been right all along.

Some people take more radical approaches to managing their memory. A friend of mine mostly converted from Perl 4 to Python, which due to syntactic limitations is not very suitable for one-off scripts on the command line, as his scripting language. He told me that whenever he has to perform a text processing or a similar task from the command-line, he edits a new file in his text editor, which also gives him some boilerplate to write his script, edits it, saves the file, and finally calls it from the command line. If I did something like that whenever I wrote something on the command line, I would quickly become extremely unhappy, but I suppose it is a useful approach if one is most comfortable with Python for such tasks.

Awk is not completely useless, and may sometimes need to be used for extra portability when old, antiquated or kept-minimal-on-purpose Unix systems, are involved, and is of important historical significance. However, in my case, I don't see a point in knowing it. If I need to learn it, I learn it enough to write what I need, and, like Sherlock Holmes, try to quickly forget it because I know I won't readily need this knowledge.

Naturally, this extends to other fields aside from computing. One of my pupils for private lessons testified that he had photographic memory, and for the history matriculation examination, he memorised the entire books, and during the exam wrote an paraphrased answer based on his memory, and as a result, got a very high grade, and eventually forgot most of it. Similarly, my sister, who now studies medicine, told me that she and her fellow students often memorised a lot of material in preparation for the examinations, only to forget it and then learn it again for a different examination, that also covered the same material. This makes me question the effectiveness of the methodology behind medical education, but still reinforces the original point.

The Other Side of the Coin

On the other hand, your knowledge and understanding of it should not be too specialised either, because one can infer many parallels from different fields of knowledge, and reach conclusions, because all knowledge is contiguous. By learning a little of everything and anything, you can often handle situations and have clearer thinking and greater creativity.

In my screenplay Star Trek: “We, the Living Dead”, I describe an optimal situation of this in the “Planet of the Hebrews” where scholars each take different units of study and learn any that they want, and eventually are judged based on the number of units they learned, and the amount of useful contributions they have done. And you still shouldn't rule out that someone less experienced, younger, or less qualified, than you will be able to do as well, or even better than you (see what Paul Graham wrote about “amateurs” in “What business can learn from open source?”).


This document is Copyright by Shlomi Fish, 2006, and is available under the terms of the Creative Commons Attribution License 3.0 Unported (or at your option any later version of that licence).

For securing additional rights, please contact Shlomi Fish and see the explicit requirements that are being spelt from abiding by that licence.


Despite enjoying captioned images for a long time, I am late to the game of creating them. You may know them as lolcats, and they are also sometimes called “memes”, although the term “meme” is used for any unit of thought and more than just. However, I recently created three of them using Wikimedia Commons, or Google Image Search, as well as GIMP and Inkscape, and realised it is incredibly easy to do. I now truly understand why their low barrier to entry - almost everyone can take a photo of a cat or whatever and caption it - makes them so subversive, and why the Cheezburger network is being blocked by both Iran and China.

I have done some work on Star Trek: “We, the Living Dead” (which is now close to being in a mostly usable state) and “Selina Mandrake - The Slayer”, which combines a Buffy the Vampire Slayer parody and tribute (with a conscious and constant referencing of the original show) with many more elements. An Indian software developer, with whom I talked on the Internet, and who did not watch Buffy, said it was still very funny, so there may be hope for me yet.

Cheers, all.

Tags: holmes, memory, psychology, sherlock, software
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