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Effective Shell Part 1: Navigating the Command Line

about 1 month ago | Dave Kerr: dwmkerr.com

Text in the command line can quickly get unwieldy. Here are some simple tricks you can use to navigate in the command line.

Promises, Async and Await in Node.js

about 2 months ago | Rocky Jaiswal: Still Learning

This week we had the much awaited Node.js 8.0.0 release! Node is getting faster and better all the time. This release also makes the async / await feature available natively. But before we look at async / await let us quickl ...

A utility to help you wait for ports to open

about 2 months ago | Dave Kerr: dwmkerr.com

There are occasions where you might need to have scripts or commands which wait for TCP/IP ports to open before you continue. I've come across this need again and again when working with microservices, to make my life easier I've created a little utility called wait-port which will wait

Engineering Leader: How to make a difference?

2 months ago | Subodh Gupta: Subodh's Blog

Being an engineering leader is not an easy task, especially when you are stepping into this role as a first-timer. Seldom you go through a training, however in most situations you are expected to figure it out yourself with little or no guidance. Often leadership demands you to play following roles: People ManagerProduct/Business knowledgeArchitect/Senior DeveloperVision for technologyI will be writing separate blogs to cover the first two roles. For a beginner, last two roles are very important to gain credibility of the team which is the most important factor in succeeding at your job. As a technical leader, you will be facing the challenges from all the directions like decision making, improving team efficiency and choosing the technology roadmap for your team. However, I hope adopting following patterns can help you sail through these challenges. Decision Making: When hit with the problem, as a techie you rely on your technical skills and often start suggesting solutions immediately which is fine in few situations, however in my experience better way would be to ask pointed questions to lead your team in driving the right decision. Questions should be repeatedly asked to highlight the blemishes in the suggested design. For example, "How would you take care of security?", "How are you addressing scalability?", "How would application behave under these circumstances?" and many more. It's easier to jump to the solution by picking up the first suggestion by trusting the loudest (not literally) person in the room. However, as a coach, you should be involving everyone in the decision-making process. Find out what is missing in the room, is it the knowledge, the skill or the participation. You need to create enough opportunities for everyone to participate. To do that you need to think about various factors like structure of the team, personalities in the team etc. These factors can be neutralized to an extent by bringing everyone to a common understanding of the problem. In my experience, following preparation before hosting an important meeting would make it easier: Share a document explaining the problem which can educate the team before the discussionDuring the meeting, explain the problem in detail so that team can align their understandingDo your homework before going to the meeting. This will help you in asking the right questions and guiding the meeting towards the solution. Improving Efficiency: Team delivers to the full potential if they are not disturbed and allowed to focus on the problem. As a leader, think about how the team is getting distracted, how can you make them focus on stories or task in hand? Improve the development processes so that you can minimize the impact on the team. For example, in a production issue churn out the non-technical part and direct developer towards solving the technical problem. Vision for Technology: Successful teams stay ahead of the technology curve. As a coach, you need to ensure that your team is adapting to changing landscape of the technology world. While working with your team to strengthen the technology muscle, you need to start focusing on what should be the future technology platform for your team. If you are not thinking at least 3-months down the line, you will lose the war while you were busy fighting battles. Be sensitive to what role you are playing in your team. You are not a developer anymore, you are a coach and coaching means understanding before suggesting, listening before speaking, advising rather than commenting. As a beginner, starting in the world of unknown unknowns of management, I hope my secret sauce can help you prepare the right dish for your team!!!

Techniques for Efficiently Learning Programming Languages

3 months ago | Daniel Higginbotham: Flying Machine Studios

Learning programming languages is a skill: do it well and you'll experience one dopamine hit after another as you master something new; do it poorly and you'll feel constantly frustrated and even give up. What follows are the best techniques for learning programming languages that I've picked up over years of teaching programming by writing books and articles, doing talks, and running a training course. Many of these techniques are pulled from books explaining the latest research in efficient learning, and you can find those books (along with other great programming books) at Community Picks: Learn Programming. Test Yourself Constantly to Defeat The Illusion of Competence One of the worst ways to learn is to re-read or re-watch material. This kind of review gives you the feeling that you understand the topic covered because it seems like you're understanding the topic effortlessly. Researchers call this the illusion of competence. A significantly better approach (and one of the best techniques you can employ) is to test yourself constantly. Instead of re-reading what a function or class or object is, ask yourself to define these concepts or use them in a short program; force yourself to somehow demonstrate your understanding. This process often feels uncomfortable, but it's much more efficient at forming long term memories. You can take this one step further and test yourself before you've covered the material by, for example, attempting exercises before reading a chapter. Remarkably, this has also been shown aid memory formation. The impressive impact that testing has on learning is called the testing effect, and here are some specific ways you can take advantage of it: Before reading a chapter or watching a video, try guessing at what you're about to learn and write it down. Try doing a chapter's exercises before reading the chapter. Always do exercises, even the hard ones. It's OK to give up on an exercise and come back to it later (or never, even), but at least try it. (More on this in the next section.) Read a short program and try to recreate it without looking at the original code. Or, go smaller and do this with a function. Immediately after learning a new concept like objects, classes, methods, or higher-order functions, write code that demonstrates that concept. Create diagrams that illustrate concepts, both in isolation and how they relate to each other. Blog about a concept you just learned. Try explaining the concept to a non-technical friend. (I did this a lot when writing Clojure for the Brave and True; being able to explain an idea in layman's terms forces you to understand the idea deeply.) Many of these techniques boil down to write some code! With programming it's easy to believe we're learning a lot just by reading because programming is text-heavy and conceptual. But it's also a skill, and like any other skill you have to perform it to get better. Writing code is the best way to reveal your incorrect assumptions about programming. The faster you do that, the faster you can make corrections and improve. If you'd like to learn more about the testing effect, check out make it stick: The Science of Successful Learning. Take Time to Unfocus If you're stuck on a problem or don't understand something you just read, try taking a walk or even a shower -- anything to enter a relaxed, unfocused state of mind. It probably seems counterintuitive that one of the best ways to get unstuck is to stop trying for a little while, but it's true. The problem is that it's easy for us to put on mental blinders when we're focusing hard on a problem. I mean, that's pretty much what "focus" means. But by focusing hard, we're exploring only a small portion of the solution space. By unfocusing, our unconscious mind is able to explore and make connections across vast swaths of our experience. To me it's like when you're trying to find a destination on a paper map (remember those?). You can unconsciously become convinced that the city you're trying to reach should be right here! in the upper-left qudrant of the map, so you look at it over and over without success. Then you put the map down and take a deep breath and stare at nothing for a minute, and when you look at the map again the actual location jumps out at you immediately. We've all had the experience of having a sudden insight in the shower; now you have a slightly better understanding of why that happens, and you can employ the technique on purpose. Personally, I will actually take a shower if I'm stuck on something, and it's remarkable how well the technique works. And how clean I am. If you'd like to learn more about the focused and diffuse modes of thinking, check out A Mind for Numbers: How to Excel at Math and Science (Even If You FLunked Algebra). Don't Waste Time Being Frustrated Related to the last section: don't waste time being frustrated with code. Frustration leads us into doing stupid things like re-compiling a program or refreshing the browser with the hope that this time it will be magically different. Use frustration as a signal that there's a gap in your knowledge. Once you realize you're frustrated, it can help to take a step back and clearly identify the problem. If you've written some code that's not working, explicitly explain to yourself or someone else the result that you expected. Use the scientific method and develop a hypothesis for what's causing the unexpected behavior. Then test your hypothesis. Try again, and if a solution still eludes you, put the problem aside and come back to it later. I can't tell you how many times I've thrown my laptop in disgust over a seemingly unsolvable problem, only to look at it the next day and have an obvious solution pop into my head immediately. This happened last week, even. Identify Which Programming Language Aspect You're Dealing With Personally, I find it useful to keep in mind that when you're learning a programming language, you're actually learning four things: How to write code: syntax, semantics, and resource management The language's paradigm: object-oriented, functional, logic, etc. The artifact ecosystem: how to build and run executables and how to use libraries Tooling: editors, compilers, debuggers, linters It's easy to get these four facets mixed up, with the unfortunate result that when you run into a problem you end up looking in completely the wrong place. Someone who's completely new to programming, for example, might start out by trying to build iOS apps. They might try to get their app running on a friend's phone, only to see some message about needing a developer certificate or whatever. This is part of the artifact ecosystem, but an inexperienced person might see this as a problem with how to write code. They might look at every line they wrote to figure out the problem, when the problem isn't with their code at all. I find it easier to learn a language if I tackle each of these aspects systematically, and in another blog post I'll present a general list of questions that need answering that should help you in learning any language. Identify the Purpose, External Model, and Internal Model Whenever you’re learning to use a new tool, its useful to identify its purpose, external model and internal model. When you understand a tool's purpose, your brain gets loaded with helpful contextual details that make it easier for you to assimilate new knowledge. It's like working on a puzzle: when you're able to look at a picture of the completed puzzle, it's a lot easier to fit the pieces together. This applies to languages themselves, and language libraries. A tool's external model is the interface it presents and the way it wants you to think about problem solving. Clojure’s external model is a Lisp that wants you to think about programming as mostly data-centric, immutable transformations. Ansible wants you to think of server provisioning in terms of defining the end state, rather than defining the steps you should take to get to that state. A tool's internal model is how it transforms the inputs to its interface into some lower-level abstraction. Clojure transforms Lisp into JVM bytecode. Ansible transforms task definitions into shell commands. In an ideal world, you wouldn’t have to understand the internal model, but in reality it’s almost always helpful to understand a tool's internal model because it gives you a unified perspective on what might seem like confusing or contradictory parts. When the double-helix model of DNA was discovered, for example, it helped scientists make sense of higher-level phenonema. My point, of course, is that this blog post is one of the greatest scientific achievements of all time. Tutorials often mix up a tool's external model and internal model in a way that’s confusing for learners; it's helpful to be aware of this so that you can easily identify when it's causing you frustration. Spaced Repetition Helps You Remember Spaced Repetition been proven to be one of the best ways to encode new information in long-term memory. The idea is to quiz yourself at ever-increasing time intervals to minimize memory decay using the fewest number of repetitions. The Guardian wrote a great introductory article. Sleep and Exercise Take care of your body! It's more than just a vehicle for your brain. If you want to be able to stay focused and learn efficiently, getting adequate sleep and exercise beats the pants off caffeine and energy drinks. More tips? If you have any useful tips, please leave them in the comments! If you'd like more excellent resources on learning to program, check out the Community Picks: Learn Programming, a community-curated collection of the best books for learning programming. It includes a wide array of subjects, including introductory programming books, books on craftsmanship, and books on soft skills and interviews.

Kubernetes with ELK Setup

4 months ago | Rocky Jaiswal: Still Learning

As it turns out this is my 100th post. The first one was published in March 2011 and a lot has changed since then. A lot of new technologies have come in and a lot of my posts have become obsolete. In all these years nothing has created more i ...

Tips and Tricks for Beautifully Simple Mobile App CI

4 months ago | Dave Kerr: dwmkerr.com

In this article I'm going to demonstrate some simple tips and tricks which will help you build and maintain beautifully simple mobile build pipelines. These techniques can be applied to different mobile app technologies and integrated into almost any build system: Sample App Index Each tip is demonstrated in the sample apps in

Testing HapiJS with Jest

4 months ago | Rocky Jaiswal: Still Learning

HapiJS and React are pretty much my go-to technology choices for web application development right now. While Jest works really well with React, on the HapiJS side I was ...

Zen and the Art of Blowing Things Up

4 months ago | Daniel Higginbotham: Flying Machine Studios

The Dark Knight came out at the same time that I was becoming intensely interested in Buddhism, and the movie struck me as a kind of extended Buddhist parable, with Bruce Wayne as an icon of the suffering that results from clinging and the Joker as a very fucked up enlightened being. Here are some of my main reasons: (warning: spoilers!) Suffering and Impermanence Buddhism teaches that suffering comes from constantly scrambling for stability in an unstable world. Nothing is permanent, but we strive mightily to hold on to the illusion of permanence, only to suffer when reality once again asserts itself. In the scene where Batman is in the interrogation room beating the stuffing out of the Joker, the Joker just laughs and says, "You have nothing! Nothing to threaten me with. Nothing to do with all your strength." And that cuts to the heart of who the Batman is: a person whose reaction to the first shock of impermanence (his parents dying) was to dedicate his life to developing his strength so that he would never experience that pain again. The Batman's entire being is an exercise in doing just one... more... thing... to establish control. I mean, who would want to live that life? And here's the Joker, ready with the Zen slap: he tells Batman where to find Harvey and his girlfriend Rachel, giving him the illusion of control over who to save. And we know how that turned out: the Joker lied to the caped crusader, telling him Rachel was at one address, but actually Harvey was there. Batman races to save Rachel, only to find find Harvey instead. Nothing to do with all that strength. This really hit home for me because, at the time, I was in a relationship with someone that had a chronic illness. I could try to do everything to make her life less painful and more enjoyable, but there was only so much I or anyone could do. Natural Metaphors and Endless Desire At one point, the Joker says, "I'm just a dog chasing cars, I wouldn't know what to do if I caught one." Or something like that. This is a double whammy: "a dog chasing cars" is totally something a zen master would say, but besides that it expresses our human tendency to constantly strive for the next thing. We're all just dog chasing cars, not knowing what to do when catch one. You get a job: now you want a better job. You get a house: now you want a bigger house. Better to just say fuck it, put on some makeup, and start blowing up hospitals. No Self The Buddhist idea of "no self" is actually somewhat nuanced and I'm purposefully misrepresenting it here, but it would be difficult to argue that the Joker clings to any notion of self in the way that most of us non-enlightened psychopaths do. He gives multiple stories for how he got his scars, revealing the Buddhist truth that our sense of self is just a story we tell ourselves and that no one story is better than any other. He gives up his name and identity to become a fucking clown. And people really hate clowns! Interconnectedness One Buddhist teaching is the idea of interconnectedness: that we are all one, but not in the wavy-gravy way your high uncle used to ramble about. My take on the idea is that it's related to no self: you cannot point to a "you" that is separate from the world you exist in. It's a fallacy to believe your "you" is somehow different from the collection of experiences of the world, so that you are inextricably intertwined with the world. You can't point to one thing outside yourself and say "I am not this," because you are pointing at it you moron, and so in that moment who you are is a guy pointing at that thing, and life is the accumulation of such experiences of things outside of "you." ANYWAY I am totally not your high uncle, OK? Point is, the idea of interconnectedness is meant to foster a sense of compassion. You can see that at the end of the movie when the Joker plays his hilarious "blow up the other boat" gag. Two boats full of strangers become enlightened, refusing to do harm to people they haven't even met. The Dark Knight remains one of my favorite movies of all time, and it inspired a Batman obsession that took years to subside. (Ironically, obsession is a fairly un-Bhuddist behavior.) If you're a Batman fan too, check out Batman Community Picks for the best Batman books and movies. Or if you're interested in Buddhism, check out Buddhism Community Picks for the excellent books.

Get up and running with OpenShift on AWS

6 months ago | Dave Kerr: dwmkerr.com

Setting up your own OpenShift cluster can be a little complex, but in this article I'll show you how to make it fairly painless.

WFFM: Save to Database

6 months ago | Sumit Bajaj: Sumit Bajaj's Blogs

Web Forms For Marketers has become one of the essential component of Sitecore. Almost every website is using forms to capture the inputs from users and it is very common scenario to get the data stored in Database for reporting purpose. Here are few easy steps which can help you storing the form's data in SQL database.Download the WFFM - SQL Provider(Save To Database) and install it in Sitecore using Installation wizard. All physical files and Sitecore items will be stored in respective location.Once installed, you will notice that it has created a new Action under System-> Modules -> Web Forms for Marketers -> Settings -> Actions -> Save ActionsNow, we have to add connection string in configuration file which will help us storing the data in that database. You have to keep the name of connectionstring to 'wfm' only as same name is referred in WFFM module code.< add connectionstring="user id=your_db_user_id;password=your_db_password;Data Source=your_db_server;Database=your_db_name" name="wfm" >You are done.Now add the 'Save to Database' action on any WFFM form and start using it. Also validate the database and data should start getting stored in it.Furthermore, this module provides the capability of exporting the saved data in CSV format. We can do customization on it to export the data from different servers(CMS or CD) which I will explain in next article.Please don't hesitate to contact me at 'email.bajaj@gmail.com' for any Sitecore related query/scenario.

Pointers in C and x86 Assembly Language

6 months ago | Pat Shaughnessy: Pat Shaughnessy

16GB of DDR random access memory my son used in his new gaming PC Recently I’ve been trying to learn how to read x86 assembly language. In http://patshaughnessy.net/2016/11/26/learning-to-read-x86-assembly-lang

Creating a Resilient Consul Cluster for Docker Microservice Discovery with Terraform and AWS

7 months ago | Dave Kerr: dwmkerr.com

In this article I'm going to show you how to create a resilient Consul cluster, using Terraform and AWS. We can use this cluster for microservice discovery and management. No prior knowledge of the technologies or patterns is required! The final code is at github.com/dwmkerr/terraform-consul-cluster. Note that

Learning to Read x86 Assembly Language

8 months ago | Pat Shaughnessy: Pat Shaughnessy

A 16-bit Intel 8086 microprocessor from 1978 (source: RodolfoNeres via Wikimedia Commons) Writing assembly language is

Using Slack for Server Development

8 months ago | Dave Kerr: dwmkerr.com

I recently found a surprisingly helpful approach for server-side development which uses Slack in a creative way.

Docker Registry with AWS & Let's Encrypt

8 months ago | Rocky Jaiswal: Still Learning

With pretty much all new projects moving to Docker and Docker managers like Kubernetes, the Docker Registry becomes the first piece of infrastructure that a team needs to setup. Sure there are public and private registries availa ...

Simple Continuous Integration for Docker Images

9 months ago | Dave Kerr: dwmkerr.com

In this article I'm going to demonstrate a few tips and tricks which can make your life easier when you are building or maintaining Dockerfiles. The need for a Build Pipeline Do we really need any kind of continuous integration or build pipeline for Dockerfiles? There will be cases when

Run Amazon DynamoDB locally with Docker

9 months ago | Dave Kerr: dwmkerr.com

tl;dr: Run DynamoDB locally using Docker: docker run -d -p 8000:8000 dwmkerr/dynamodb Try it out by opening the shell, localhost:8000/shell: DynamoDB Shell That's all there is to it! DynamoDB Amazon DynamoDB is a NoSQL database-as-a-service, which provides a flexible and convenient repository for your services. Building applications

Need a Second Opinion on Your Ruby Code? Ask Crystal

10 months ago | Pat Shaughnessy: Pat Shaughnessy

Running the Crystal compiler on your Ruby codeis like asking a second doctor for their opinion. When it comes to your health, you don’t hesitate to get a second opinion. Doctors don’t always agree, and a second doctor’s app

Hello Kubernetes

10 months ago | Rocky Jaiswal: Still Learning

Introduction Pretty much everyone in the technology world has heard about Kubernetes by now. But before we dive into it, let's try and understand the problems it solves - Back when I started programming, servers were usually considered out of reach for us developer ...

Effective Node.js Debugging

11 months ago | Dave Kerr: dwmkerr.com

If you are interested in improving your Node.js debugging skills, then check out my talk at the recent JSChannel 2016 conference in Bangalore: Comments and observations are always welcome!

My Writing Process

11 months ago | Daniel Higginbotham: Flying Machine Studios

The letter below is a response to an email from a Twitter friend. For context: I've written some instructional material that's enjoyed success online, including Clojure for the Brave and True and Clean Up Your Mess: A Guide to Visual Design for Everyone. Robert asked me a few questions about my process. Hi Robert! You're in the unfortunate position of being my permission to write at length about my creative process without seeming completely self indulgent: someone's actually interested in listening to me describe the chaos between my ears! Be prepared to read way more than you asked for. How do you decide who you are writing for? This one’s key for me. When I’ve written in the past, I’ve struggled with knowing how much or how little to say. I’m curious to learn how you deal with that. First: I've found it useful to follow the standard advice and pick an individual or two and write for them. The argument goes that you'll find it much easier to choose words and have a consistent tone, and that's proven true for me. When I wrote Clean Up Your Mess, I was one of three programmers working in an office full of charming people who did business analysis for management consultants, and I wrote the guide for a couple of them that I had become friends with. These analysts produced powerpoint decks by the barrel, and every single one was ugly. Similarly, Clojure for the Brave and True started as a guide for a couple coworkers that I was mentoring. However, picking your audience is only half the process. The other half is picking who the author is. I'm going to go on a bit of a tangent to explain this. When I started writing Clean Up Your Mess, my personal life was a mess. In hopes of making it less messy I had been spending most of my free time reading Buddhist literature and listening to lectures by Thich Nhat Hanh and Pema Chodron (in fact, my site opens with a Thich Nhat Hanh quote). I was spending a great deal of time meditating and reflecting. (You're interested in Buddhism too, right?) One of the ideas that really grabbed me was that our self-conceptions are just stories we tell ourselves with no reality to them. I won't belabor the point here; suffice to say that I found it useful and powerful to be able to perceive my identity as a construct as ephemeral as smoke. Around the same time, I started taking improv comedy classes, where I would spend two hours a week constantly coming up with new, unique characters and living in them for a few minutes at a time. When you're sold on the idea that your day-to-day you is itself just a character, improv becomes way easier and more fun. It's also fun to do this in real life - like, recently my wife and I were at the grocery store and I decided my character was "Super Excited About Carrots Guy", and I started shouting "OH MY GAWD JESS CARROTS! THEY HAVE CARROTS JESS! CARROTS!" Everyone was laughing as they escorted me out! Anyway, during this time of buddhism and improv I was writing Clean Up Your Mess and when I sat down to write I got to play with new identities, new characters, and see which was the most fun. It became much easier to find words and keep a consistent tone when I decided on the author's character. So, you mentioned not knowing how much or how little to write. Knowing your character helps. In Clojure for the Brave and True, one of my editors would sometimes whittle down sentences to the bone, leaving only pure information; I would undo those edits with gusto, adding back the shape and texture of the author's voice. There's another aspect of writing instructional material, which is that 95% of the time you can take more time to explain something. Even if you're writing for experienced audiences, at least take the time to explain acronyms and jargon. How often and how much do you write? Not enough and not enough! Writing was easiest, however, when I had a consistent schedule of writing at least one hour every single day. Let me tell you about my garage. My garage is a living f*cking nightmare. It's like Cthulhu and the dread of the dark you had as a child made disgusting love and produced a horde of horrors that died in giant filthy clumps all over. At the beginning of the year I suppressed my gag reflex long enough to clean it out with the goal of setting up a photo studio, which I did, only to let it sit for three months. So three months later I go in there to actually take photos and guess what: it's a complete horror show, again! If I had only spent time every day or even every week maintaining it, I'm sure it would have been much easier to keep clean. If I had cleaned it out, all those tiny insect monsters wouldn't have been able to breed, there wouldn't have been two dozen spider egg sacs, etc. When I don't write consistently it's like that. I have to crawl into the nest of no one cares what you write and this time everyone's going to hate it called my mind and clear it all out before I can actually start writing. When I write consistently, on the other hand, it's actually quite pleasant! One more note: much of the writing process is research. Every time I find myself struggling to explain something, it's because I don't understand it well enough. When that happens I put down the keyboard and pull out the pen and notebook. I try to articulate the questions that will lead me to understand what I want to explain. I read and I draw diagrams and play with words until I feel like I understand the concept. Becoming aware that, for me, writer's block is a lack of understanding, has helped me be much more productive. Collaboration Who does your drawings? My wife! She's pretty great. Do you have someone who edits for you? I did when I worked with No Starch. They were awesome! Clojure for the Brave and True is much, much better because they kept pushing me to write more clearly and explain things more fully. For other projects, I'll ask friends to look at drafts. How much does it cost? I paid my wife in carrots. OH MY GAWD JESS THEY HAVE CARROTS! No Starch gets 85% of hard copy sales and 77.5% of ebook sales (or something like that). I hope this was helpful!

Understanding Recursion

12 months ago | Daniel Higginbotham: Flying Machine Studios

During my Clojure training I've found that recursion routinely trips people up. It definitely tripped me up for a long time. I've tried to develop an explanation that's clear and intuitive, so if you're still scratching your head about recursion, read on! A classic recursion example is calculating n factorial, which is n multiplied by every natural number before n; 3 factorial is 6 (3 times 2 times 1), 4 factorial is 24, 5 factorial is 120. The code snippet that follows is a typical implementation of factorial; if you're reading this, then presumably it's confusing - which is great! It means that I haven't written this article for nothing. function factorial(n) { if (n == 1) { return n; } else { return n * factorial(n - 1); } } What makes this function recursive is that factorial calls itself. That's also what makes the function tricky; the function calls itself!? We're used to functions calling other functions to get work done. For example, this function uppercases a string and prepends "Yo, " to it: function yoShout(str){ return "Yo, " + str.toUpperCase(); } yoShout("gimme a donut"); // "Yo, GIMME A DONUT" In this tiny example, yoShout does its work by using the toUpperCase function. It's easier to understand than a recursive function because yoShout treats toUpperCase as a black-box abstraction. You don't have to tax your brain by loading toUpperCase's implementation details into your short-term memory. Let's re-write factorial to use function calls this way, with function's body calling another function in order to get its work done. To calculate 3 factorial, you could write a series of functions, factorial_1, factorial_2, and factorial_3, like this: function factorial_1() { return 1; } function factorial_2() { return 2 * factorial_1(); } function factorial_3() { return 3 * factorial_2(); } These functions feel safe and comfy. factorial_3 calls factorial_2, something we're completely familiar with, and likewise factorial_2 calls factorial_1. factorial_3 also does not care how factorial_2, just like in the string example. Unfortunately, these functions are also completely impractical; can you imagine writing factorial_1000? The recursive implementation doesn't have this problem. My suggestion is to try seeing the recursive implementation from the same perspective as the nonrecursive imiplementation. Here's the code again: function factorial(n) { if (n == 1) { return n; } else { return n * factorial(n - 1); } } You can look at this and say, "Oh, if n isn't 1, then this function does its work by calling some black-box function named factorial with the argument n - 1." You can look at the call to factorial(n - 1) as a call to a completely different function - one that just happens to have the same name and algorithm. That's it! I hope it helps. If you've been confused by recursion, I'd love to hear your feedback!

Pi Calculation with Elixir

about 1 year ago | Rocky Jaiswal: Still Learning

As a programmer one is always searching for better tools, practices and programming languages. For example, working with Clojure makes me a better programmer, it provides me the ability to write functional, succinct code that runs fast and works on the well-tuned and battle-tested JVM. Looking at ...

F#: Disabling SSL Certificate validation

about 1 year ago | Kristof Mattei: Kristof's blog

Yesterday I wanted to download some content off a website with F#, however unfortunately the certificate of the website was expired. let result = try let request = "https://somewebsite/with/expired/ssl/certificate/data.json?paramx=1&paramy=2" |> WebRequest.Create let response = request.GetResponse () // parse data let parsed = "..." Ok parsed with | ex -> Error ex If we execute this, … Continue reading "F#: Disabling SSL Certificate validation" The post F#: Disabling SSL Certificate validation appeared first on Kristof's blog.

F#: Disabling SSL Certificate validation

about 1 year ago | Kristof Mattei: Kristof's blog

Yesterday I wanted to download some content off a website with F#, however unfortunately the certificate of the website was expired. let result = try let request = "https://somewebsite/with/expired/ssl/certificate/data.json?paramx=1&paramy=2" |> WebRequest.Create let response = request.GetResponse () // parse data let parsed = "..." Ok parsed with | ex -> Error ex If we execute this, … Continue reading "F#: Disabling SSL Certificate validation" The post F#: Disabling SSL Certificate validation appeared first on Kristof's blog.

HTTP Compression and Performance tuning

about 1 year ago | Sumit Bajaj: Sumit Bajaj's Blogs

With the advancement of technology and exceeding expectations of users, one has to be very careful designing a website. Performance is one of the key elements for success of an application. Even if, you have designed the application with uttermost care and rock solid architecture, there are few key areas in which you have to be really vigilant. HTTP Compression is one of those pivotal spaces.HTTP compression is the technique to compress static and dynamic content which improves the transfer speed and performance of a website.Steps to keep the compression ON for a website. Here the demonstration is given for IIS based website.1. Open IIS (inetmgr)2. Goto website. Right side will show all components of that website3. Click on 'Compression' module and verify that both the checkboxes are checked if you need static and dynamic content to be compressed.4. Click 'Mime Types' and check 'application/x-javascript' is added in the existing mime types. If not, add it.5. Reset IIS, browse website and verify that JS is getting compressed now.Web.Config SettingsHere are all the mime types and gzip information which should exist for a website if compression needed, either in IIS settings or in web.config.Note: Include it in web.config if configuration file also get deployed with every build.Section to include in <system.webserver></system.webserver><system.webServer><httpCompression> <staticTypes> <add mimeType="text/*" enabled="true" /> <add mimeType="message/*" enabled="true" /> <add mimeType="application/javascript" enabled="true" /> <add mimeType="application/x-javascript" enabled="true" /> <add mimeType="image/jpeg" enabled="true" /> <add mimeType="*/*" enabled="false" /> </staticTypes> <dynamicTypes> <add mimeType="text/*" enabled="true" /> <add mimeType="message/*" enabled="true" /> <add mimeType="application/javascript" enabled="true" /> <add mimeType="application/x-javascript" enabled="true" /> <add mimeType="image/jpeg" enabled="true" /> <add mimeType="*/*" enabled="false" /> </dynamicTypes> <scheme name="gzip" dll="%Windir%\system32\inetsrv\gzip.dll" dynamicCompressionLevel="4" /> </httpCompression></system.webServer>After compression is ON:Response header of a JS file being loaded in website. 'Content-Encoding: gzip' shows that it is compressed.Useful toolsThere are several webistes which can help you detect, if your website/CSS/JS is compressed or not. You should check css/js or website seperately to make sure that all static medias are compressed. One of the examples website is given here.Check CompressionFor further detail, you can contact me www.bajajsumit.com. Please share your feedback if you find the article useful.

Testing the Docker for Mac Beta

about 1 year ago | Dave Kerr: dwmkerr.com

I've finally had a chance to install the new Docker for Mac Beta and give it a whirl, here are my experience so far!

Is it worth persevering with Golang?

about 1 year ago | Dave Kerr: dwmkerr.com

After perhaps 10-20 hours of learning, coding and messing around, I'm wondering - is it worth persevering with Golang?

What's your Vim Name?

about 1 year ago | Dave Kerr: dwmkerr.com

I'm a few weeks into moving to Vim as my main editor, I've stopped crying and shaking mostly (at least about my editing ability). Now I'm wondering: what's your Vim name? And who's got the best one? As far as I can work out, my Vim name is: Replace everything

Quick Tip: Sending Newlines with cURL

about 1 year ago | Dave Kerr: dwmkerr.com

Yikes, this took far too long to figure out! I have a service which takes plain text multiline input and outputs an object for each line, something like this: Input Line 1 Line 2 Line 3 Output [ {line: "Line 1"}, {line: "Line 2"}, {line: "Line 3"} ] There's a bit more

Classes and patterns in Node.js

about 1 year ago | Rocky Jaiswal: Still Learning

This week we had the awesome Node.js 6.0.0 release! With the 6.0.0 release Node.js has 93% of the ES6 features implemented. In this short post we will look at few particularly interesting features including "classes in JavaScript", ...

Moving from React + Redux to Angular 2

about 1 year ago | Dave Kerr: dwmkerr.com

I'm going to share my experiences of experimenting in Angular 2, as someone who needs a pretty compelling reason to move away from React/Redux!

Learn Docker by building a Microservice

over 1 year ago | Dave Kerr: dwmkerr.com

If you are looking to get your hands dirty and learn all about Docker, then look no further!

Running dotnet on Linux

over 1 year ago | Sumit Bajaj: Sumit Bajaj's Blogs

Server: Linux, version SUSE 12To run dotnet code on Linux, the first and foremost task is to "Install Mono package on linux".Note: Mono is an open implementation of Microsoft's .Net framework, including compilers. It uses the same development libraries on Linux which are being used on Windows. Therefore, if you code and compiled some mono code on Linux,  it will work for Windows as well.      zypper is a package installation tool which is used in this scenario. If zypper is not available, check which package manager tool is installed on server. Furthermore, to verify if zypper is installed or not, type zypper on command line which will show all options if zypper is available on server else it will show 'command not found'.zypper ar -r http://download.opensuse.org/repositories/Mono/SLE_11_SP2/Mono.repoThe above command will download from mentioned URL in a new repository. Here 'ar' stands for 'add repo'.After adding it to repository, type 'zypper refresh' command, it will ask to install packages. Type the appropriate option and install the Mono packages.Once successful installation,       we are all set to run dotnet on linux server.Running first dotnet codeCreate a new test.cs file by typing following command.$cat>test.csNow open the file using any available editor. In this case it is 'vi' editor.vi test.csStarting writing the first dotnet code as shown below.      Information about 'vi' editor:Type 'i' to change it to insert mode.Type 'esc' to come out of insert mode.Type ':w' to write the file and save.Type ':q' to quit and come back to command line tool.       NOTE: If any exception appears like '!' is required to override the file. Type ":w!" to override the existing file and write the new text. OR Type ":q!" to override the existing file with new text and quit.C# code for 'test.cs':using System;namespace Test1{class Test1{static void Main(string[] args){Console.WriteLine("Hello World!!");}}}Once you have saved the file, its time to compile it. 'mcs' is command which is used for compiling the code.dev-server-linux-suse12:~ # mcs test.csAfter compilation is successfully completed, its time to run the application. As it is console project, '.exe' file will be created as output. 'mono' is the command used for running the test project.dev-server-linux-suse12:~ # mono test.exeHello World!!You are all set to run dotnet on Linux. Provide your valuable comments/suggestions.

Two Dumb Ruby Mistakes

over 1 year ago | Pat Shaughnessy: Pat Shaughnessy

Coding is like climbing: You need equipment that will catch you when you make a mistake. (source: Elke Wetzig via Wikimedia Commons)

Packer, Ansible and Docker

over 1 year ago | Rocky Jaiswal: Still Learning

A little while back we looked at an operational setup that can get us up and running with any simple application by using Docker and capistrano. What was missing was the setup of the machine itself, we do not want to ...

Timeless Programming Tools

over 1 year ago | Daniel Higginbotham: Flying Machine Studios

I've been programming professionally for a dozen years. Some of what I've learned is best forgotten (oh god, Cold Fusion), but there have been many tools, techniques, and concepts that continue to be useful every day. Here are mine; I'd love to hear what yours are so I can experience both the joy of discovery and regret for not learning about the tool earlier. Relational Algebra / SQL I feel lucky that, during my fourteenth summer, I apparently had no friends and so had nothing better to do than try and slog through a book on MySQL and the now-defunct mSQL. You can see from the reviews that the book "is sketchy, incomplete, and almost totally useless." But, it did introduce me to SQL and databases. Soon after, I learned relational algebra (the theory underlying RDBMSs) and that investment has been one of the best of my life. I can't count the number of times a LEFT OUTER JOIN has saved my bacon. Friends be damned! Learning relational algebra provided the foundation I needed to move easily from MySQL to Oracle and MS SQL Server when I joined EnterpriseCo, and in general knowing how to interact with databases without a framework or ORM helped me quickly advance career-wise. It's why, at 20, I was able to land a contract building a custom site for the city of Santa Fe, New Mexico, instead of just cobbling together Wordpress and Drupal plugins. If you come from Rails or some other framework that handles all the database interaction for you, one of the best things you can do for your career is to learn relational theory and SQL. Read a book by C. J. Date. The Unix Process Model Understanding Unix processes helped me understand what's actually happening when I run a program. It's also helped me understand what exactly a web server is and what I'm doing when I write a web application. The book Advanced Linux Programming has a chapter on processes for free online. Actually, the whole book is free. When you don't know about processes, programming is much harder and more mysterious. It's harder to understand performance, and it's harder to understand how programs interact with each other. If you ever feel a vague sense that you don't really get what's going when you run the apps you write, learning the process model will go a long way toward clearing things up. Regular Expressions Yeah, yeah, we've all heard the joke: "something something regular expressions, then you have two problems." Personally, I don't get it, because regular expressions are seriously badass. I remember going through O'Reilly's big fat regex book while I worked from 11pm till 7am as a night auditor at a hotel when I was 18, and being blown away at how powerful they are. To say that we programmers deal with text all the time is so obvious, it's not even worth saying. Regular expressions are an essential tool, and here's where you can learn to use them. Finite State Machines Regular expressions are built as finite state machines. Here's a great tutorial on FSMs showing how to actually build a regular expression. It's extremely cool! I think FSMs are covered in computer science 101, but since I only went to college for a year and even then I studied works written a couple millennia before before the computer revolution, I didn't actually learn about them until about six years ago. My colleagues and I were having trouble with a mobile app - we needed the initialization process to happen in a particular way, and the logic for ensuring that was getting pretty tangled. Once we took the time to learn about FSMs, though, it was easy to express the process as a series of states and transitions. I've since found that most tricky UI code can be improved this way. Just a couple months ago I was having trouble building a typeahead element from scratch with hoplon. Once I identified that the difficulty was in keeping track of all the possible states, it only took a few minutes drawing a state machine diagram and I was back on track. Emotion Management In my personal life I'm constantly learning about and practicing ways to manage emotions. This stems from both my personal aspiration to improve the lives of others and from the completely selfish reason that it helps me do good work. Emotion management is probably the most important meta-skill you can develop. I mean, emotions are at the core of who you are as a human being. The book Non-Violent Communication is an excellent resource for dealing with emotions. Also, my friend Alex Harms recently wrote a book specifically for technical people. Those are my programming power tools - I hope you find them useful!

Cannot alter the login 'sa', because it does not exist or you do not have permission.

over 1 year ago | Sumit Bajaj: Sumit Bajaj's Blogs

Working on projects, it can happen that 'sa' account gets locked. If it is on local machine OR development boxes, onus would be on you to fix it. If scripts and SQL steps are not working, this might help you fixing the issue.Steps to unlock 'sa' account and resetting the password.1. Open SQL Server Configuration Manager2. Select SQL Server Services -> 'SQL Server' service.3. Right click on 'SQL Server' service and click on "Startup Parameters". For 2008, server "Startup Parameters" are inside Advanced tab. 4. Add '-m' in startup parameters as shown above and click on 'Add'. This will put SQL server into 'Single User Mode' and local admin will have 'Super User' rights. For 2008, server you have to add ':-m' in the last of the existing query.5. Save the settings and Restart the service.6. Now open the SQL Server Management Studio and connect to database using 'Windows Authentication'.7. Goto Security -> sa -> Right click and open properties.8. Unlock the 'sa' account and reset the password.YOU ARE DONE!!**Important: Now to switch back to 'Mixed User Mode' where you can access the database using 'sa' account, remove the '-m' from 'Startup Parameters' which we added in above steps.

Brave Clojure: Become a Better Programmer

over 1 year ago | Daniel Higginbotham: Flying Machine Studios

Next week week I'm re-launching www.braveclojure.com as Brave Clojure. The site will continue featuring Clojure for the Brave and True, but I'm expanding its scope a bit. Instead of just housing the book, the purpose of the site will be to help you and the people you cherish become better programmers. Like many other Clojurists, I fell in love with the language because learning it made me a better programmer. I started learning it because I was a bit bored and burnt out on the languages and tools I had been using. Ruby, Javascript, Objective-C weren't radically different from each other, and after using them for many years I felt like I was stagnating. But Clojure, with its radically different approach to computation (and those exotic parentheses) drew me out of my programming funk and made it fun to code again. It gave me new tools for thinking about software, and a concomitant feeling that I had an unfair advantage over my colleagues. So of course the subtitle of Clojure for the Brave and True is learn the ultimate language and become a better programmer. And, four years since I first encountered Rich Hickey's fractal hair, I still find Clojure to be an exceptional tool for becoming a better programmer. This is because Clojure is a fantastic tool for exploring programming concepts, and the talented community has created exceptional libraries for such diverse approaches as forward-chaining rules engines and constraint programming and logic programming, just to name a few. By learning a variety of programming concepts, you become a better programmer because you're better able to recognize what kind of problem you're working on and apply the right tools. To give just one example: when I'm working on complex UI widgets my work is always made easier if I model the widget using a finite state machine (FSM) - but I had to actually spend time learning what FSMs are and how to use them (those of you with comp sci degrees are probably chuckling at this). You may have started learning Clojure because you heard that functional programming, Lisp, and immutability can make your life easier, but the fun doesn't stop there! At Brave Clojure, I hope you'll continue using the ultimate language to explore the vast and infinitely fascinating world of computer programming with me. The first topic we'll explore is parallel programming. Here's the beginning of an ebook on the topic that I'm nearly finished with: Yes, it would be fair for you to describe my startup as the Google of palm reading. I don't know if you know this, but the fortune telling industry has no quality control standards. There is no Six Sigma of fortune telling. Sometimes it seems like these people are just making things up! We can do better. Did I say we? Yes! I want to you to embark on this startup journey with me. Lucky you! My - our - plan is to disrupt the field with an app that lets a user position their phone so that the camera faces their palm and takes a picture, then predicts the future. I call it: iFacePalm. And, uh, there's parallel programming in it. While I plan on spending most of my time helping you and all of your closest friends, enemies, and even frenemies become better programmers by writing about these big ideas, I'm also going to spend time covering practical Clojure topics like deployment and debugging. To make this happen, I'm working a (great) job only two days a week and spending the rest of the time on Brave Clojure, so I'll need to find a way to derive income from the site. I'm not sure yet what will be free and what won't. My dream is to make all the content available online for free. That's what gives me joy, and I think it's the best way to have a positive impact. Ideally, I would be supported in this endeavor through monthly donations, but I'll likely try different approaches over time. Finally, I've been putting together two sites to help you up your game: Open Source Clojure Projects, a directory of active projects, and Clojure Work, the first Clojure-only job board. The latter is still in beta, and I'm going to officially release it and move it to https://jobs.braveclojure.com next week. The best way to get better at Clojure is to actually write Clojure, and working on real projects (and even getting paid to do so) is a great way to do that. Companies who buy job board ads will also be supporting me in making more content - hooray! If you get excited about learning more programming ideas, or learning to develop Clojure programs better, or getting paid cold hard cash to write your favorite language, then I cordially invite you to consider signing up for my newsletter, where I'll announce every release: Writing Clojure for the Brave and True was one of the most rewarding experiences of my life in large part because I got to interact with so many kind, thoughtful, intelligent people. I look forward to your company as I embark on this new chapter of my journey!