Running Open MPI on macOS

I am, generally, against all these automation stuff (brew, etc.) at macOS. I prefer to install everything from sources (as long as it is possible).

So, here are few steps to get Open MPI up and running at macOS. Please make sure to download source package from:

Now, it’s time for Hello world! code.

And, eventually, we can compile and run it

That’s all.

Get all hidden files inside $HOME

Simple one liner that helps to find all config locations inside your HOME directory

In case you like more bass, the same way I do ;)

apps keep asking for key chain access

1. Open Key Chain Access and unlock all key chains

2. use security utility to set timeout for keychain

You can read more about security using man

Scratch Coding Cards by Natalie Rusk

Summary: So far, the best Scratch Coding resource I have found :)

“Old school” way of learning (one that industrial era developed) is based on reading. To know something, you have to read something. Well, that’s not always the best idea. And let me remind you, that an old philosopher, long, long time ago in a land far, far away, said:

You know, Phaedrus, writing shares a strange feature with painting. The offsprings of painting stand there as if they are alive, but if anyone asks them anything, they remain most solemnly silent. The same is true of written words. You’d think they were speaking as if they had some understanding, but if you question anything that has been said because you want to learn more, it continues to signify just that very same thing forever

– Socrates

And that’s exactly what it is whet it comes to learning from books. You are always left with the content as it is, and you can hardly discuss anything with it.

Let’s be honest, reading is really boring nowadays. You have so many, various, sources of knowledge: youtube, online courses, tutorials, podcasts, screencasts, etc.

Even more, sometimes you don’t need them at all. All you need is just an inspiration. Idea of what can be done, and how can you achieve it. You don’t need all the steps, described one by one. You don’t need full recipe. General idea is more than enough. After you know what you are looking for, all you need to do is to experiment and try to achieve it.

This is exactly the way you can learn using Scratch Coding Cards. By far, this is the most engaging and most powerful tool to teach Scratch I was dealing with. I have some experience with teaching Scratch and I know that finding good way of engaging kids into Scratch is quite challenging. There are few things I done in past. Like, fighting very bad and powerful Knight – you can find him at youtube. Or, some ideas quickly sketched on a piece of paper: here (my beloved Moleskine notebooks ;) ). However, they require either following the instructions, strictly, when you watch video or they require someone extra comment from teacher – like in case of Scratch UML.

When it comes to Scratch Coding Cards, it’s all different. All you need to do, is to give one of the sets to kids, and they will solve it. That’s the beauty of this Box full of cards. Kids are simply shuffling cards, looking at them to check what can be done and which blocks are important, and few minutes later solution is there.

What you get inside the Box (which is firm and solid) are 75 cards.

Cards are grouped into activities (challenges you are supposed to code). Each challenge can be solved by following steps presented on cards. Together with my kids, we have found that strict following of the order is not required.


Each card describes some activity and show you how to achieve that. It’s supper simple. Note that my kids are non english speakers and they were still able to follow cards by simply looking and images. This was really cool!

And, one more comment. There was no cheating at all. Kids were given cards and I slowly shaded away :)

If you are looking for some ideas and new, fresh way of teaching Scratch, make sure to check this one. Really worth it.

Have fun!!

Printed: Scratch Coding Cards

ldd in macOS

Redirecting http traffic

Sometimes, simple solutions are the best

Mr. Robot – some thoughts about bugs

Most coders think debugging software is about fixing a mistake, but that’s bullshit.
Debugging’s actually all about finding the bug.

Coding apprentice – TODOs

Coding apprentice:
– Hi there. Well, you know, there are lots of TODOs inside code.
What does it mean, really? Is it: This One Datelessly On-site?

If you have makefile that has weird name but you still want syntax highlighting