Here’s something fun to try. Create a text file that looks like this (Note: utf-8 encoded!):
A ß C ßa ßz a B b c S s SS ss SA sa SZ sz
Just to be really clear, here are the exact bytes I’m talking about:
$ hexdump -C /tmp/foo.txt 00000000 41 0a c3 9f 0a 43 0a c3 9f 61 0a c3 9f 7a 0a 61 |A....C...a...z.a| 00000010 0a 42 0a 62 0a 63 0a 53 0a 73 0a 53 53 0a 73 73 |.B.b.c.S.s.SS.ss| 00000020 0a 53 41 0a 73 61 0a 53 5a 0a 73 7a 0a |.SA.sa.SZ.sz.| 0000002d $ md5sum /tmp/foo.txt ac2be5e453dd79c070da74d0e67aa6b2 /tmp/foo.txt
Now, compare the output of the following commands:
$ sort /tmp/foo.txt $ LC_ALL='en_US' sort /tmp/foo.txt $ LC_ALL='en_US.utf8' sort /tmp/foo.txt $ LC_ALL='en_US.iso88591' sort /tmp/foo.txt $ LC_ALL='C' sort /tmp/foo.txt $ LC_ALL='de_DE.utf8' sort /tmp/foo.txt
How’s that for rocking your world? So, the next time your friend says “hey, can you return those results sorted for me?” then you’ll have something really fun to think about when you can’t sleep at night.
And just when you thought “Oh, well great, at least all the UTF-8 versions sort the same” then comes along this little gem:
$ LC_ALL="jp_JP.utf8" sort /tmp/foo.txt
Oh, and just when you thought “Well, I guess I’ll be OK with en_US.utf8 and at least English will sort the way I want worldwide!” then along comes your friends to the North with this awesome zinger:
$ LC_ALL="en_CA.utf8" sort /tmp/foo./txt
Here’s a programming challenge / interview question that I like to think about, and gives me that tingly feeling of “I think there’s a really clever, efficient algorithm for this” but I haven’t been able to come up with a really clever answer yet. Here’s the problem:
Given a file containing N random positive integers less than N, write a program that runs on O(n) time and produces a collection of sorted files containing the input data, but where each file is itself in strictly sorted order.
Give it a try and send me the code and we can compare algorithms. I’ve been working with N=10000 and have a solution that produces about 200 unique sorted files, and can get as good as about 160 unique sorted files if I allow a fixed constant sized space usage (i.e. a small internal buffer).
I like to think of this operation as “semi-sorting”. The output is a collection of sorted files, which can be merged together by a traditional merge operation.
You’ve got a great development setup and now you want to “do the right thing” in production.
You’re using virtualenv (good!)
You’re using “pip install…” for all your dependencies (good!)
You’re probably not keeping a requirements.txt up to date (that’s OK!)
You’re using “django-admin.py runserver” or similar (not gonna cut it!)
You’ve got all your source code in a git repo (self hosted or github or other, good!)
You’re ready to write your first fabric script! (good!)
Now let’s get that code out to production!
I’ve commented in the past about how Android fragmentation isn’t really as huge of an issue as some developers have made it to be. But, there is one elephant in the room that no one is talking about:
Android fragmentation and lack of updates increased damages in the Apple vs. Samsung lawsuit.
How? Why? Well, the sad truth of it is that Android is evolving over time to be “less infringing” on Apple patents. One great example of this is the “bounce-back scrolling feature” patent. This feature did not exist in Android 1.x, was implemented (poorly, I might add) in Android 2.x, and was then removed in Android 3.x and 4.x and replaced with a non-infringing color-overlay scrolling feedback mechanism.
So, if Samsung (or any other vendor) had been able to keep devices up to date more quickly, they would have been less liable to Apple for damages. Similarly, if they had been quicker to adopt new Android versions (say, 4.0) then they would not be liable for any damages against this patent.
There are many other examples of how Google is evolving the Android User Interface to NOT infringe on Apple patents . This is the first case that I can think of where fragmentation (more specifically: Lack of keeping software versions up-to-date) has cost anyone real money. By the books, it’s Samsung who’s paying, and maybe this means they’ll be more aggressive with keeping up to date.
I also hope Google sees this lesson, and helps the hardware manufacturers with hardware drivers and other issues that hold back software on many devices.
Here, have this pile of links:
I’m going to keep updating this list as I find more, so check back. I’ve already added 3 new links since I first wrote this.
Here’s a thought:
Wouldn’t it be awesome if your bash prompt could show you:
Well, all this is possible (and more, probably!). I worked a bit on getting all these features working this afternoon. The source code is pretty rough, but I think this could be useful enough for others that I should start to share it. I’ll likely put this in it’s own github repository eventually. But, for now, here’s a simple gist with my ~/.bash_prompt source.
To use this, just copy it to your home directory, and add the following to the bottom of your ~/.bashrc:
This is totally non-obvious, so here goes.
At a shell prompt, run:
$ gnome-desktop-item-edit ~/.local/share/applications/mylauncher.desktop –create-new
Go through the dialog to create the launcher and make sure you give it an easy to remember name. When you’re done, that application should show up under “Applications” in that search thing.