Várkért Bazár

Last month we went to see the recently renovated Várkert Bazár –literally “Castle Gardens Bazaar”— in Budapest’s castle district, here are some photos.

Rooting Samsung Galaxy Mini

Samsung Galaxy Mini

Samsung Galaxy Mini

My wife’s phone (Samsung Galaxy Mini GT-S5570I) doesn’t get system updates any more, so I need to manually move Google’s updates into ROM to make space for regular apps. You need root privileges to do this, so I was following these instructions on the XDA Forum which almost work fine. You need to download and apply a file update.zip but the problem is the update script inside doesn’t include S5570I in the list of phone models it checks for, so the script aborts.

All you need to do is edit /META-INF/com/google/android/updater-script inside update.zip and include this phone model in the assertion list, for example, I duplicated lines 15 and 16 and just added an I to the end:

getprop("ro.product.device") == "GT-S5570" ||
getprop("ro.build.product") == "GT-S5570"  ||
getprop("ro.product.device") == "GT-S5570I" ||
getprop("ro.build.product") == "GT-S5570I"  ||

Everything works completely fine after that. Obviously this is not a general solution when rooting, you can’t just blindly add your own phone model into any update.zip not knowing what’s in it, but since this was from a post for specifically this model and it already had several very similar models listed, I thought it was worth the risk and it turned out just fine. Woop! 😎

grml zsh inPlaceMkdirs

I keep forgetting this, but it’s really useful when working in the command line so I’m writing it down now. I use the grml zsh configuration in my shell and it has several very good features; a cool one I’d use more often if I could remember the shortcut is “in-place mkdir”. The key sequence is:

Ctrl-X, Shift-M

That’s Ctrl and x, followed by an uppercase M.

Here’s an example use case: Imagine you’re writing a command to do something with a very long path, like moving a file deep into a source tree

mv File.java src/something/very/long/

except half-way in your realise some of the directories in that path don’t exist. No problem! Usually you’d have to cancel that command, create the missing directories and then type it again. Now you can just type Ctrl-X, Shift-M, the directories are created and you can just press enter to use them. Much less annoying! This can even work for different directories in the same command; move the cursor to the directory you need and zsh will create that one!

For other useful shortcuts, see the reference card.

Secured my site with Let’s Encrypt

You might notice if you browse this blog now, that it’s served over HTTPS. I’ve even added an Apache configuration to redirect plain HTTP requests to secure HTTPS and I’ve spent the last few days checking the pages for URLs including non-secure content and rewriting them to use HTTPS where possible, or otherwise removing them. You’ll also notice in the left-hand corner of the browser’s address bar, there’s a (hopefully familiar) little green lock which indicates:

  • your communication with the site is encrypted well
  • the authenticity of the site is verified by a trusted authority

Of those, the latter usually involves paying a trusted certificate authority a lot of money to verify and sign your site’s certificate so that browsers will mark it trusted. Security is important but this high cost often creates a barrier for small companies wanting to use https. Continue reading

Mathematical Range Summing

Immediately after the last post about summing a range of numbers, a talented friend of mine, Gábor, offered an even shorter, cleverer solution:

What I especially like about it is that instead of relying on esoteric JavaScript functions to do the job, it’s done with reasoning and plain maths, which makes it clearer and easier to read too.

The Maths.abs() call is only needed because in the original problem, the arguments could be in either order; the logic is still the same though, you just need to make sure the range is positive. In short, it’s (a+b) × (a-b+1) ÷ 2.

Sum All Numbers in a Range

A solution to Free Code Camp’s “Sum All Numbers in a Range” JavaScript challenge, in a Functional Programming style.

A friend of mine hosts meetups for the Free Code Camp, which describes itself as:

We’re an open source community of people who learn to code and help nonprofits.

He organises casual meetings in coffee shops to allow participants to work on their assignments in a nice environment and help each other. If you’re looking to learn programming I recommend finding a Free Code Camp group in your area.

Today I visited such a meeting and one of the Code Campers was working on a solution for one of the JavaScript problems in the Intermediate Algorithm Scripting section. The task was to write a function that takes an array of 2 numbers as an argument and returns the sum of all the numbers between them, including the 2 numbers themselves. For example, an input of [3, 1] should result in 6, because 1 + 2 + 3 = 6. As a hint, it’s recommended you read the documentation for Math.min(), Math.max() and Array.prototype.reduce(). Continue reading