catonmat.net
Visit catonmat.net → RSS feedOn Hacker News May 2008 – Nov 2024
Software Engineering 42Tools & Productivity 18Math & Algorithms 9Web & Frontend 7Systems & Performance 7Startups 5
The most random and amazing things happened at my company Browserling in the last few weeks. Someone in India discovered that they can use WhatsApp on very cheap $20 phones (Jio Phones) via Browserling. These cheap phones can't run WhatsApp but if you go to Browserling, you can use it via web.whatsapp.com. He made a...
I was reading about vim the other day and found out why it used `hjkl` keys as arrow keys. When Bill Joy created the vi text editor he used the ADM-3A terminal, which had the arrows on hjkl keys. Naturally he reused the same keys and the rest is history. Here is how the `hjkl` keys looked. ADM-3A keyboard's hjkl…
A couple of days ago I watched a How Computers Learn talk by Peter Norvig. In this talk, Peter talked about how Google did machine learning and at one point he mentioned that at Google they also applied machine learning to hiring. He said that one thing that was surprising to him was that being a winner at…
I recently learned an interesting fact about Fibonacci numbers while watching a random number theory video on YouTube. Fibonacci numbers can be used to approximately convert from miles to kilometers and back. Here is how. Take two consecutive Fibonacci numbers, for example 5 and 8. And you're done converting. No...
I decided to write an article about a thing that is second nature to embedded systems programmers – low level bit hacks. Bit hacks are ingenious little programming tricks that manipulate integers in a smart and efficient manner. Instead of performing operations (such as counting the number of 1 bits in an integer)…
Update: StackVM is now called Browserling. Hey everyone, I have awesome news! I am doing a startup together with James Halliday! I met James on FreeNode several years ago and it turned out that we had very similar ideas about doing great hacking. So we teamed up as equal co-founders to do a startup. We're on…
At Browserling we are huge open-source fans and we have open-sourced 90 node.js modules! That's right! 90 node.js modules. All written from scratch. We're crazy! Edit: Now we've open-sourced several hundred! Here is the complete list of all the modules together with their brief descriptions. We have published all…
I thought I'd share my favorite regex of all time. [ -~] Any idea what this regexp matches? Scroll down for the answer. . . . . . . . . It matches all ASCII characters from the space to tilde. What are these characters? These are all printable characters! Take a look at this ASCII table. Printable characters start…
I was recently interviewed by Fog Creek and one of the questions was about my favorite programming, coding and development books. I got very excited by this question as I'm a huge book nerd. I love books about computers, programming, and science. Every few months I spend a day or two researching the latest…
A couple of days ago I watched a How Computers Learn talk by Peter Norvig. In this talk, Peter talked about how Google did machine learning and at one point he mentioned that at Google they also applied machine learning to hiring. He said that one thing that was surprising to him was that being a winner at…
Hi all! I'm starting a new article series here. This one is going to be about Unix utilities that you should know about. The articles will discuss one Unix program at a time. I'll try to write a good introduction to the tool and give as many examples as I can think of. The first post in this series is going to be…
Hey guys, here are the lastest StackVM news. So we applied to Y Combinator for the Winter 2011 funding cycle but got rejected. On November 2 we got an email saying that they could not accept our application for funding, which meant that we wouldn't even get the interview. Our plan was to surprise Y Combinator folks…
The `ldd` utility is more vulnerable than you think. It's frequently used by programmers and system administrators to determine the dynamic library dependencies of executables. Sounds pretty innocent, right? Wrong! In this article I am going to show you how to create an executable that runs arbitrary code if it's...
In this video, Alan Kay talks about his vision of object oriented programming and how to design scalable systems.
Hi everyone! Here's part three of my favorite programming, computer, and science books. If you're just joining, please see part one and part two for introduction. This time I'll be sharing my favorite books about Unix, logic programming, thermodynamics, and mathematical foundations of computer science. In one of the...
Hi everyone! Here's part five of my favorite programming, computer and science books. If you're just joining, please see part one, part two, part three and part four. I've been collecting and researching science, math, physics, programming books since 2001 or 2002, so it's been close to 15 years of book research…
Many people are surprised to learn that `sed`, a seemingly simple text filtering program, is actually Turing complete. This realization prompts the question: how can a text processing utility achieve such computational power? The answer lies in sed's fundamental operations. Essentially, sed functions as a miniature...
Hi all! I'm starting a new article series here. This one is going to be about Unix utilities that you should know about. The articles will discuss one Unix program at a time. I'll try to write a good introduction to the tool and give as many examples as I can think of. The first post in this series is going to be…
I love working in the shell. Mastery of shell lets you get things done in seconds, rather than minutes or hours, if you chose to write a program instead. In this article I'd like to explain the top one-liners from the commandlinefu.com. It's a user-driven website where people get to choose the best and most useful...
Here's something you didn't know about bash functions. Usually when you write a function you do this: function name () { ... } Right? I know you do, because that's how everyone writes functions. Well, here's the thing. In bash { ... } doesn't mean "function's body" or "function's scope" as in JavaScript or C. It's...
As you all may know, I watched and posted my lecture notes of the whole MIT Introduction to Algorithms course. In this post I want to summarize all the topics that were covered in the lectures and point out some of the most interesting things in them. Actually, before I wrote this article, I had started writing an...
This is the third post in the article series about Unix and Linux utilities that you should know about. In this post I will take you through the useful lsof tool. If netcat was called the Swiss Army Knife of Network Connections, then I'd call lsof the Swiss Army Knife of Unix debugging. Lsof follows Unix philosophy...
This is the second post in the article series about Unix utilities that you should know about. In this post I will introduce you to the netcat tool or simply nc. Netcat is often referred to as a Swiss Army knife utility, and for a good reason. Just like the multi-function usefulness of the venerable Swiss Army…
You have probably all heard the following story about Jobs meeting Knuth for the first time in 1983. Steve had managed to get Don Knuth, the legendary Stanford professor of computer science, to give a lunchtime lecture to the Mac team. Knuth is the author of at least a dozen books, including the massive and somewhat...
I recently learned an interesting fact about Fibonacci numbers while watching a random number theory video on YouTube. Fibonacci numbers can be used to approximately convert from miles to kilometers and back. Here is how. Take two consecutive Fibonacci numbers, for example 5 and 8. And you're done converting. No...
Frameworks are one of the hugest anti-patterns in software development. They're hard to learn. They limit your creativity. They increase your project's complexity and dependencies. They go out of business and get abandoned. You have to maintain and upgrade your code to match the latest framework versions for no good...
A while ago I had an on-site job interview at Google. The position I was interviewing for was a Google SRE. SRE stands for Site Reliability Engineering. Site reliability engineers (SREs) are both software engineers and systems administrators, responsible for Google's production services end-to-end. I interviewed…
Long story short, I went to Silicon Valley and found angel investors for my Browserling startup that I am doing together with James Halliday (SubStack). James Halliday, our lead investor and advisor David Weekly, and me. Here is how I did it. Last year in March, James offered me to do a startup. He had this idea of...
This is the fifth part of the Bash One-Liners Explained article series. In this part I'll teach you how to quickly navigate around the command line in bash using emacs-style keyboard shortcuts. That's right, emacs-style keyboard shortcuts. It might surprise you but by default bash uses emacs-style keyboard shortcuts...