Computer Science - Brian Kernighan on successful language design 

The fact that someone added subtitles to this video is incredible

Thank you for making this talk available to the public.

Man...this guy is just incredible. He has almost a legendary status in the history of computer science yet he is so humble and so down to earth. His presentation skills are just awesome -I didn't loose focus even once during whole video, which happens every 30 seconds when the profs at my uni try to teach. He explained everything in very clear and concise way, no BS at all. No trying to sound smart, no cryptic explanations, no ego at all. I wish lecturers at my uni were a bit more like him...

I literally owe my career to Mr. Kernigan. As a young programmer writing PL/1 and COBOL code on IBM MVS platforms, I discovered "The C Programming Language" in the library in 1984 and checked it out as a curiosity... I'd never heard of the language. The terseness of the language and elegance of his examples in the book blew me away! I knew I had to learn this language - even though I really liked PL/1 , so I bought the only C compiler available for a PC at the time (Whitesmith's C Compiler), and taught myself the language. A year later I was working in Unix and C for a major Aerospace company and never looked back. Thank you Mr. Kernigan.... my career was a blast because of you and Dennis Richie, et. al.

His lecture is electrifying, and he's 70s, put many younger guys to shame. A legend yet so humble and not condescending to his audience like current conference speakers. Top guy.

I like to imagine that this humble man uses Comic Sans in his code editor as well. Great talk and thanks for C!

I could listen to Prof Kernighan speak all day long. What a clear thinker

13:54 I've noticed something that could be a pattern. Many legendary scientists seem to be humble in general and are not afraid to admit that their knowledge is limited. On the other hand, there are many people that are very arrogant, in contrast to what they have achieved (i.e. not much). I couldn't expect less from such a legend... Thank you U.o.Nottingham for sharing this lecture. And thank you Prof. Kernighan, for C and Unix.

The man who introduced him taught me language design.

That's how you do an intro, people. 5 seconds and get the star on stage.

CS == Computer Science? No CS == C#? No. CS == Comic Sans? Yes!

Someday, I would love to possess 1/10th the knowledge and humility that Brian Kernighan has.

11:26 "People in 70s discovered, that you could program in the command interpreter." Microsoft in 2009: "I think now I'm starting to get it..."

B.K..?! Hands down.. Couldn’t agree more that RU-vid is a real treasure island in our time. Thank you

Another reason I would add that (partly at least) helps some languages to thrive is marketing. Most of the most well-known languages of the new millennium (e.g. C#, Go, Swift, Rust) were developed or backed by major companies (Microsoft, Google, Apple and Mozilla respectively). The most successful language is not alway the one with the best specs, but with the best hype.

The 64 dislikes are all pure functional programming programmers.

Sure, Brian Kernighan is a great, but have you ever seen better camera work and speaker/slide transition timing in a university lecture? Incredible!

At 25:07 you have the most concise example of an associative array. Period. Thank you Dr. Kernighan for this precious gem.

Comic Sans improves ALL presentations!

58:12 - "But you wonder whether it [C++] has passed beyond some threshold of complexity that's beyond mortals." 😂

I still picture him reclining in the chair describing how Unix works.

I write a lot of python scripts in Linux, and 9/10 if I need to do some kind of data handling for files, I just have the python script run an awk command. Python is no slouch at file processing, but an awk one liner can usually do the trick :)

To be precise: 06:11 - this is not the 1961 CACM cover, because TMG and PL/I were not invented yet in 1961. This is the tower from the 1969 Sammet's book. CACM cover of January 1961 did feature a reference to the Tower of Babel, however, it listed slightly fewer languages.

Sincere huge thanks to the transcriber(s) of this video.

C is a very complicated language. Not in the language itself, but also in it's coupling with the OS, take POSIX compliance, vs POSIX certified, vs Windows Certified or even DOS. Compliance with C89, C99, 2017, etc.

I would say that today a language is more defined by the existing tools you can use with it than by the language itself.

Always a pleasure to here Brian speak. Thanks for posting!

I once made a web server in C, and everyone seemed to be arguing that there would be a threshold, such that their interpreted language would run faster. I even tried to hammer the site, and there is NO point that ASP was a better choice (lol). There is no limit where ASP, or another other backend will surpass C.

This man IS a true legend..

It is always a pleasure to hear Brain Kernighan speak

I bought a wallet from the University of Nottingham and it fell apart within a year. This talk was so good that now I feel I owe you money.

I have used AMPL in MIT edx course on supply chain management. I used it for modelling linear programming to find optimization values using constraints.

Amazing talk. Learned so much about the evolution of languages from the master himself. I'm now inspired to read about a bunch of languages that I've not explored 😀

Thank you for sharing this. That was wonderfully enlightening.

Very nice talk. Arguably, everything a programmer does is design languages/interpreters thereof. We write functions (interpreters) that take data[structures] (source code) and do something with it. Then you name all that stuff and there you have a (programming/declarative/configuration) language. Often, it is not worth or helpful to define your own parser taking textual source code to obtain your syntax tree, since there are now many standard ways to represent the kind of labeled graphs that all programs are textually or as nested datastructures in any language (html with extra attributes, nested associative arrays [json/yaml], S-expressions...). In fact, please don't define your own parser for key-value data like so many unix programs did in the past, just because it (seems) so simple.

A legend. You gave us so much sir. I learned C just because a lot of modern langages I use (Java, C#) use its syntax and I thought it was a way to honour the creation of C that to learn C and C++ even if I don't use those at work, just to honor the great work. Thank you sir. My job and life today are the result of all that fine work you did with Ritchie :-)

This is one of the best presentation I've seen in a while. Simple explanation for complicated topic. I think I'm going to learn a new programming language... Thanks

Wonderful video, thanks you so much

Thuis guys knows stuff.. and shows how to age gracefully.

Unix, C and AWK are parts of my life. I love you!

"strongly-hyped" XD

Why a language succeeds: All those reasons, plus the creator needs to have a beard.

Fasacinating. Thank you.

I vaguely recall watching this two years ago, now with some more general programming experience I find it much more informative, very good stuff. I even used AMPL about 6 months ago, super useful for supply chain optimization but the documentation is ...haphazard, plenty of it but you must dig through hundreds of pages of tutorial style docs spread across two dozen PDF files, it really has no solid "man page" style syntax summary, doubly so for the data syntax.

I am not computer science but i worked with computer - I used his UNIX C book.

Fantastic talk :)

What a great presentation! :)

At 28:50 on SWIFT, precisely right. Same with JS frameworks.

Is it just me or does anyone else too feel his voice seem much younger than his face?

Incredibly interesting.

I don't know how I managed to miss this event!

Pascal with a few (small) extensions/modifications worked fine as a systems programming language. So did Algol. Bliss was definitely used as a systems programming language. So was Mesa. So was PL/I (but that one was probably too complicated). Cobol with a few extensions has been used to implement a (fast!) Cobol compiler so it could probably also have been used as a systems programming language.

I was one of the people who had to do system programming in Pascal. Back in the 1980's I worked for NCR doing application programming on automated cash machines (ATMs). Even though it was application programming (business logic) it had many system aspects and ATM programming was not trivial. Intel did have a suitable language for their real iRMX OS (called PL/M I think), that was used to write device drivers and managers. But it was considered too hard for application developers and so Intel's Pascal/86 was mandated (I think this was a re-branded version of Pascal/MT). This was an extended version of Pascal designed to be used as a "real" language. It had support for include files, separate source code module, overlays, variable length arrays (only when passing parameters between different modules), assembly language support -- but I never used that. It worked surprisingly well, but I would not want to do that again...

I love troff and im happy to see it get mentioned in this video. I make videos on troff on my channel for those of you that are interested.

I miss lectures.

I've never noticed Brian's name on my copy of the AMPL book. Quite a surprise.

I would have shouted perl to the first question, because I'd be done writing it and running it before most would get their boilerplate done. Though it would take 5 minutes to write it pretty and make it obvious how it worked for any later maintainer. But for problems like the one-shot mentioned above, a really simple text split and numeric compare on a field - and you're done. Maybe 3 lines if you were being super explicit. I love C and use it daily. C++ - well, some of it is good, but trying to use ever more complex constructs and bizarre template syntax (the template engine itself is Turing-complete without any cods at all, as Damian Conway demonstrated) is a dead end - adding complexity to cure complexity. But for a simple one-shot task? In most cases developer time costs more than computer time, and perl is better for those. Parsing that out in C vs using a language meant to do parsing is not a win. Ah, so (on viewing further) our hero says AWK - and that's a great choice, if you know AWK. I know perl, so, horses for courses. And make no mistake, this guy is a hero.

This guy carries 1.5x speed by himself so I don't have to use it😂

Is that comic sans? Legend!

The Wizard of Computer Science

Good call on the swift thing

He says you should teach associative arrays to undergrad. students. In C, how do you use assoc. arrays? Should we implement it each time from scratch? In Python, for instance, we have dictionaries. What is the preferred way to use hashmaps in C?

Right on the spot, Java: Strongly-hyped

Professor, How do you think about Forth language and Forth machine?

Epic video!

I used bash, sed and awk to handle my references for generation of bibtex for latex documentation when doing my thesis.

I think Pearl was simply displaced by Python and Bash(as most non-compact systems have moved to Bash from posix sh since the peak growth of Pearl), Python became preferred for the heavy scripting end because it is easier to read and thus maintain for subsequent users even though Pearl may have some advantage for the original authoring. Python(with all the extensions) also has more uses and users, simple populatrity.

amazing

Strongly-hyped: Java

PopQuiz: What is the dollar amount in precious change that Brian is playing with in his pocketses?

I wrote this exact program in Java.

Are Brian's slides available?

what a legend

Amen to his comments about Swift... I got so tired of the radical changes that broke code that they'd make to the language with EVERY new version.

Simon Peyton Jones uses Comic Sans... Brian Kernighan uses Comic Sans... If you want to design a language, use Comic Sans.

@35:00 sparse matrices??? Sure, I've had to deal with these all my life in computational physics. But I also do research these days in Clifford algebra, and this talk struck me suddenly: why not use Clifford algebra structures instead of sparse matrix algebra? I'll bet this could simplify a lot of code and produce faster run times. (The mathematical basis is sound: all matrices can be recast into Clifford algebra, but in a Clifford algebra you do not need all the zeroes for a sparse matrix, instead you are using just basis vectors, and combining them as multivectors.)

"good programming langauge shouldn't make you think differently. It should just let you express what you want." -- me

Ocaml is multi-paradigm, not only functional

very good Talk, Can you Please any one help me with Presentation document which is sharing in talk, the dropbox down load link is broken , now working, Thanks in Advance

is AMPL a more heavyweight MiniZinc?

Interesting he didn't mention Smalltalk on that list.

The lecture is great, Kernighan simplay awesome, but the sound is difficult

I know this will apply to nobody else, but he talks and jokes JUST like my band director, and that makes me like him that much more lmao

this is a moment

3:36 "Aboot" :)

Five fifth decious include posion design.

Came for Brian Kernighan, stayed for Comic Sans.

Editing the audio to filter background noise would be great, but hey, it's not that big a deal.

55:04 when he talks about why Java didn't work out for the web, isn't that how wasm works?

I have a BSCS, class of 2000. After OOP, all they ever said was document, document, document. Upon graduation and getting into industry, I determined that the last thing a programmer would EVER do is document their code. It's nothing more than digging your own grave. Once management got the juice, you would be fired with no warning. Then they hoped your "budget" replacement could maintain your code. Ha! The more obscure and abstruse your code, the better off you were!

Thankfully the whiteboard notes will only ever be read by machines, so the fact that they're effectively flashcards shouldn't matter too much.

Scheme... bad memories for me. I studied CS at University on Montreal with the creator of scheme. We had to bootstrap Scheme in Scheme as assignment. By far the worst course I did, and my only abandoned course. And did Simula in Programming 101 and 201.

strtok is tricky!

Brian, I really like all the videos you are in here on Y-Tube. Have you ever tried C#? I was avoiding it for several years. Looked like another toy language. Really not that bad and simple to use.

I came here just to listen to Brian Kernighan... so it came as a nice surprise to see the video was from that RU-vid favourite Uni. Nottingham and to see the talk introduced by Prof. Brailsford. I like how he goes over some shortcomings of C and they're all problems with the standard library.... not the language itself.... "Because I invented it... it's perfect" ;) Now, I must admit, I'm an anti-Java bigot... but "Strongly hyped" particularly tickled me. As for functional languages in "the real world".... you gotta remember that, despite it's silly name, JavaScript is LISP dressed up as C... and all the best JavaScript programmers (HELLO!) are functional programmers.... well sort-of... not quite.... but sort-of.... y'know.

Kernighan rules so hard

Great talk but a comment on the editing. As much as I like to look at Professor Kernighan's pretty face it would be helpful to leave his slides up long enough to be able to read them.

He kept playing with the coins in his pocket. lol

The original Macintosh system was mostly written in Pascal.

So when you have a problem just pick one of the languages you’ve written. Easy! 😂