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Edward Barnard
Ed Barnard had a front-row seat when the Morris Worm took down the Internet, November 1988. He was teaching CRAY-1 supercomputer operating system internals to analysts as they were being directly hit by the Worm. It was a busy week! Ed continues to indulge his interests in computer security and teaching software concepts to others.
twitter: @ewbarnard
Articles
Education Station: Interview Coding Challenges
By Edward Barnard
Meanwhile, the days where employees stay with the same company 20-30 years are long gone. We move around or move on from contract to contract. For many of us, this means formal job interviews. Many of those interviews include coding challenges; that can be a problem. Let’s talk about that!
Education Station: The Day the Internet Died
By Edward Barnard
The more things change, the more they remain the same. We’re taking a 30th Anniversary Tour of the Morris Worm. We’ll find that the same attacks and defenses remain in use today. It behooves us all, as modern software developers, to understand our history.
Education Station: Producer-Consumer Programming Techniques
By Edward Barnard
This month we have a “cookbook” of producer-consumer programming examples. We work through a complete example of timing production web page loads. We then consider techniques for message versioning, funneling, and feature migration.
Education Station: Producer-Consumer Programming
By Edward Barnard
Producer-consumer programming is an excellent technique for offloading work from your main application. You can scale resources to meet increased demand. You can smooth out spikes by placing your backlog in a queue. You can set aside long-running tasks such as thumbnail generation. We’ll develop a simple CakePHP application that produces and consumes via a free CloudAMQP (RabbitMQ) account. Although we use CakePHP, the principles are universal to any modern PHP framework.
Education Station: That’s Logical
By Edward Barnard
This month we practice working “close to the hardware.” We’ll see why this is becoming more important to today’s software developers. We’ll use the PHP bitwise operators to manipulate single-bit binary numbers. We’ll then take a more general look at ways to learn what we need to learn.
Education Station: Build an Algorithm
By Edward Barnard
If you have trouble making change for a dollar without a calculator, and don’t care, this article may not be for you. Otherwise, come along with me! We’ll be converting between numbering systems. We’ll create an algorithm for converting between decimal (integer) and hexadecimal numbers.
Education Station: Build an API, Part Three
By Edward Barnard
In this series, we look at using Behavior-Driven Development (BDD) and specification by example to develop a RESTful API. In Part Three, we focus on the HTTP verbs directing any RESTful API. Understanding where and when to use HTTP verbs will inform how we structure our API and affects the developer experience.
Education Station: Build an API, Part Two
By Edward Barnard
In this series, we look at using Behavior-Driven Development (BDD) and specification by example to develop a RESTful API. In Part Two we introduce Behavior-Driven Development as a way of communicating with non-developers, our stakeholders.
Education Station: Build an API, Part One
By Edward Barnard
In this series, we look at using Behavior-Driven Development (BDD) and specification by example to develop a RESTful API with JSON-formatted request and response. In Part One we introduce these concepts, design our database, and implement a minimal working API.
Internal Apparatus: How PHP Works: Show Me the Code
By Edward Barnard
We all use PHP; it’s open source, which means anyone can take a look. However, it’s not as easy as with the various PHP frameworks, because PHP is written in C and makes heavy use of C preprocessor macros. We’ll see it’s relatively readable once we know how and where to look.
Internal Apparatus: Beginning the Deep Dive
By Edward Barnard
Understanding C code requires far more than understanding the language syntax—we need to understand the environment and context. Along the way, we’ll learn more about how computers work. We’ll be taking a deep dive into how PHP implements arrays. We begin our deep dive this month by looking at the PHP executable file and PHP’s packed hash table.
Twitter for PHP Development
By Edward Barnard
The Internet Research Agency indictment carries strong implications for the software development community. We’ll educate ourselves by drilling down into examples of computational propaganda with Twitter. Then, we’ll relax and learn how we can use Twitter to further our professional development by connecting to the greater PHP community.
Education Station: What is a Real Programmer?
By Edward Barnard
We expect a shortage of software engineering talent in 2018. Those with a deeper understanding of how things work will most benefit from the shortage. Let’s bring in 2018 by taking on one of those fundamentals, binary arithmetic, but with a twist: We’ll use XOR and AND logic for our implementation.
Education Station: Shifting and Masking with a Side of Crypto
By Edward Barnard
The basics can be tricky. This month we take a careful walk-through of a few lines of cryptographic code in PHP. This leads us through the difference between ones’ complement and two’s complement representation. We achieve weirdness by combining logical AND with integer addition.
Internal Apparatus: Hash Table Collisions
By Edward Barnard
We continue our deep dive into how PHP implements arrays as hash tables. We’ll see how the collision chain works. We’re not ready to dig into the C implementation just yet, so we’ll see how to build and rebuild the hash table using PHP code. This month we’re learning how PHP arrays are stored and manipulated; next month we’ll see the C code itself.
Internal Apparatus: Patterns in the Code
By Edward Barnard
The PHP compiler source code includes many patterns that can be frustrating and intimidating, because they are so different from typical PHP code, until we understand the structure and context. C’s preprocessor has a significant role in these unfamiliar patterns. We look at several of these patterns in the compiler’s PHP Array implementation.
Learning Machine Learning, Part Three: Data Wrangling
By Edward Barnard
Part One and Part Two of Learning Machine Learning explored the machine learning (ML) workflow. We built and evaluated a K-nearest neighbors classification model. By far the most work for this classification project, behind the scenes, has been wrangling the input and output data. Since this sort of PHP/MySQL data wrangling is nothing like building a website, we’re using Part Three to build our wrangling skills.
Internal Apparatus: Memory Abstractions
By Edward Barnard
We normally don’t care about abstractions in software, because they exist to hide details we shouldn’t need to care about. However, sometimes, we do need to know the detail. An essential part of how PHP works involves memory management. This month we’ll see new ways to think of memory itself; we’ll also introduce a learning tool we’ll be using in upcoming articles. We’ll be simulating an ancient mainframe computer, and its hard-wired operator console, using modern text messages.
