VCF East: Ken Thompson interviewed by Brian Kernighan

Also I found these fascinating: The Unix-Haters Handbook (1994) has a lot of history and takes you back in time.. [link] Brian Kernighan 'interviews' Ken Thompson (2019) - Ken telling stories. They're both very funny, a very entertaining video, some stories I (and even Brian) hadn't heard. [this video] UNIX: Making Computers Easier To Use (1982) [link] Also the other day I read in the AWK book that it was mainly inspired by SNOBOL4, so looked at some SNOBOL4 books from archive.org, from 1970-2 and just before, slightly earlier than Unix history takes you back. One tells you how to organize your punch cards to feed in the program.. Another had a bibliography with many dozens of SNOBOL books. It was widely used by people in the humanities apparently; like AWK it was at home dealing with words and text.

> Brian is super modest and claims to be a horrible programmer but he is comparing himself to Ken Thompson, who he thinks is just incredible. Ken once wrote a disassembler, assembler and B interpreter for a mini-computer that ran a printer they were struggling with, in a couple of days, so that they could get it printing again. This blew Brian's mind. For the next level up here's Ken (in a very interesting conversation with Brian Kernighan about the history of Unix) describing McIlroy: > McIlroy keeps coming up. He's the smartest of all of us and the least remembered (or written down)... McIlroy sat there and wrote ---on a piece of paper, now, not on a computer--- TMG [a proprietary yacc-like program] written in TMG... And then! He now has TMG written in TMG, he decided to give his piece of paper to his piece of paper and write down what came out (the code). Which he did. And then he came over to my editor and he typed in his code, assembled it, and (I won't say without error, but with so few errors you'd be astonished) he came up with a TMG compiler, on the PDP-7, written in TMG. And it's the most basic, bare, impressive self-compilation I've ever seen in my life. This story, by the way, leads into how Ken created B (and how that was eventually improved by Dennis Ritchie into C). [0] [this video]

The article provides ancillary hyperlinks to nearly every topic mentioned, but fails to link the actual video of Kernighan speaking. Here it is: [link] In reality the subject of the talk is Kernighan’s perspective of the history of Unix at Bell Labs. The questions covered in the article are the least interesting part, and make up about six minutes at the very end—a small fraction not just of the 70-minute video, but even of the 30-minute Q&A session. In short, the headline and article are disappointing clickbait, but the video itself is worth watching for Kernighan’s relating of history and his theories about what confluence of factors made Unix successful (collegial environment, good management, overall mission…). Another worthwhile video from the same conference (in a different year) is Kernighan’s interview of Ken Thompson: [this video]

As one of few authors of an implementation of `dc` and `bc`, but one who never actually met Lorinda Cherry, perhaps I have a slightly different perspective of her work. I've read the closest thing we have to the original sources of `dc` and `bc`: the source bundled with Plan 9. It didn't take me long to read the entirety of the source because they were simple and concise. That immensely impressed me. However, I hate to say that my youth (compared to Ms. Cherry, at least) caused me to look at the source with disdain, mostly from a lack of handling errors caused by user mistakes. It took several days for me to think more carefully about the context. She was writing for herself and other programmers, who would probably be able to recognize when they made a mistake and fix it. The code has a simple elegance that mine will never have. Sure, you might call mine "industrial strength," but I think a quote by ** Gabriel sums up the difference between Ms. Cherry's code and mine: "I'm always delighted by the light touch and stillness of early programming languages. Not much text; a lot gets done. Old programs read like quiet conversations between a well-spoken research worker and a well-studied mechanical colleague, not as a debate with a compiler. Who'd have guessed sophistication bought such noise?" [1] And that says nothing of the design of her software. `dc` was, and in many ways still is, the simplest calculator that could ever exist. It was the simplest shell too, with the `!` com

The question that I'm curious about is "why does POSIX require unary negation to have a higher precedence?" Was it a "this is the way that bc worked in the 70s because it was easier to write a parser for it?" or was there some more underlying reason for the "this problem gets really icky if unary negation has lower precedence than the binary operators and makes for other expressions that become less reasonable?" It's like the Logical XOR issue ( [link] ) ... and I'm of the opinion that there's a real reason why this design choice was made. (Aside: Some other historical "why things work that way" touching on dc's place in history: Ken Thompson interviewed by Brian Kernighan at VCF East 2019 [this video] - it goes on to pipes and dc makes an appearance there again)