Alan's Lair

Ollivander

The curse of the downvote

I don't have strong opinions on Facebook - I'm not even a user anymore - but I think that the "like/dislike" mania is going a bit too far. I've read yesterday that an engineer was fired from Facebook for having a YouTube channel, but that's beyond the scope of

Ollivander

Machine Learning: a sound primer

How to start with machine learning? Some serious, yet practical, suggestions.

Mostly Unixish

Standalone, single-file, editable Python scripts WITH DEPENDENCIES

How badly I wanted something like that? The problem: Python for scripting Beside programming and data science, I find Python to be a very useful glue language; I think it's great for shell replacement when bash/zsh scripts get too complex, but there's one caveat: as long as you can

Ollivander

Application authors: please don't force users into your language or packaging details

This story has been boiling in my head since long; today I chose to (finally) publish it. Long story short: in order to use a certain application, I should not need to understand how to use the language or its packaging ecosystem. Delivery and distribution is a relevant part of

Mostly Unixish

Misaligned Expectations: investigating the expectations gap

As some of my followers already know, I'm enrolled in the great Master's program at Georgia Tech, the OMSCS. As a part of my studies, I'm doing some research to investigate the expectations gap between the higher education and the industry sectors; why does the university teach students this way?

Mostly Unixish

SCP taming: stop local silliness

Every day now and then, I get an scp command wrong. Scp is designed after commands like rcp and works totally fine for local-to-local file copy. While this can (or could) be useful in some contexts, It's not what I like to do these days; very often, if either hosts

Ollivander

Productivity, the office, and the open floor plan

There's one pattern that, nowadays, I find amusing; the productivity mantra is repeated everywhere. Everybody wants to get more productive, every company is trying to make their employees more productive. Robotics, AI: everything calls for it. From Wikipedia: Productivity describes various measures of the efficiency of production. A productivity measure

Ollivander

Command line data crunching with Python

Every time I'm doing some data crunching on the command line, I find myself juggling between sed, awk, sort, uniq, etc. While I like the UNIX way of having one tool doing one thing well, I sometimes find it slightly boring to put all the tools together, sometimes stretching their

Mostly Unixish

Git: automatically set and use multiple commit identities

Sure, git is great. Sure it is possible to use multiple commit identities in git - just set local per-repo variables. If it weren't for the fact that chances of forgetting about it is about 99.9%. Problem context When installing git, it is required to configure a username and

Ollivander

Shell scripting: short or long format options?

This is something I get asked quite a lot, so I wanted to write a piece about it. This is an extract from the manpage from GNU grep: NAME grep, egrep, fgrep, rgrep - print lines matching a pattern SYNOPSIS grep [OPTIONS] PATTERN [FILE...] grep [OPTIONS] [-e PATTERN]... [-f FILE]

Ollivander

Stopping The Internet Of Noise - A Useful Internet Back Again

The internet is getting noisy. Too noisy. Having grown up in the nineties, with 56k dial-up, I sometimes struggle to understand how little I'm accomplishing today with all the bandwidth I can leverage. There were some key factors that made the old internet so productive, by the way, and many

Ollivander

Students that don't "get" computer science - bimodality as a teaching failure

There seems to be a common belief about computer science: people either get it, or don't get it. A recent paper by the University of Toronto, Evidence That Computer Science Grades Are Not Bimodal, dispels such myth. The paper even suggests some explanations for this myth: teaching failure. We don't

Ollivander

Primitive types are not your friends

Really. Stop (ab)using just strings and integers! Yes, they're the building blocks of whatever you do. But if you abuse them, you're not taking full advantage of your Object Oriented programming language. Let me explain with some concrete example. For the sake of conciseness, I'll use Python here, but

Ollivander

Enabling Process vs Bureaucratic Process

The Process, today, is king. There're a lot of people focusing just on process, and a lot of them hold it as The True Solution to all the world's problems. Then, there're those who don't believe in process. They say, we mostly focus on people! Process is a failed attempt

Mostly Unixish

badblocks: test your mass storage!

Are you unsure whether your mass storage works properly? Do you suspect it's faulty somewhere? Verify it with a nifty tool, included in most Linux distros and in macOS if you install the ext2fs tools: sudo badblocks -swv -t random -b 4096 -c 2048 <DEVICE> It will perform

Mostly Unixish

Automated cleanup of Docker leavings

As much as I like Docker, one thing it doesn't do well: cleanup whatever is left on my hard drive after running it for a while. There're generally two kinds of Docker Waste: Exited containers. Unless you used run --rm when running a new container from an image, docker doesn't

Ollivander

Python: discover the type of an object

This seems a simple enough question: How can I discover the type of any given Python object? Suppose Python 2.7 (Python 3 is a different beast on this topic), and try implementing such function: def discover_type_of_object(obj): """ Args: obj: Any python object Returns:

Ollivander

Git Flow is superflous and complex

Some years ago, a git workflow model called git-flow took the software development world by storm. I'd always thought that the workflow was far too complex and I couldn't figure out what purpose it served. Now, after having used it for some months, I can just confirm my impression: git

Mostly Unixish

Python requests SSL and InsecurePlatformWarning

Every now and then, when using Python 2.7 < 2.7.9 and trying to access SSL resources, especially through the requests toolkit, which seems to trigger the issue frequently - but I've seen it on some combinations of pip inside virtualenv as well - you'll get an error

Ollivander

Parkinson's law and estimates

Each and every time I think about Parkinson's law, I think that Cyril Northcote Parkinson was a sort of genius, who could gain a great insight into people's heads. For the few that have never heard about it, it's as simple as: Work expands so as to fill the time

Mostly Unixish

chmod and the capital X

This is one very, very, very interesting piece of ancient wisdom. Suppose you need to change permissions for some directories. Maybe the permissions are too strict, e.g. something like 700 for directories and 600 for files, and you need to give access to some other group and not just

Mostly Unixish

Kill Me Softly: killing a process The Right Way

I was tired of repeating the same old pattern. Send a kill signal. Check with pgrep. Did the process exit? Send a kill -9. Now all my knowledge has been permanently dumped here: Kill Me Softly on GitHub If you want to kill a process by letting it to exit

Mostly Unixish

Unfreezing your desktop: when Compiz goes wrong

A desktop freeze is something that's not so rare nowadays - that's not good, but we shouldn't get desperate about that. I like Compiz with Unity Desktop on my Ubuntu Trusty very much; I feel it's a step forward compared to traditional desktops. The only major nuisance I had on

Mostly Unixish

Don't give a shell to system users - use su

I seem very ancientwisdom-oriented these days. Sometimes you've got a system user on your linux server that's used to run a specific service; it's a good practice to employ those users to achieve privilege separation, since it limits the impact of many security breaches. It's security 101, really. If you've

Mostly Unixish

SSH hostnames configuration and shortcuts

This is another old trick, but I like to tell the world about such amenities. I often find people writing command lines such as: ssh arcane-system-user@someextremelylong.andimpossibiletotype.anderrorprone.hostname.com or, worse ssh idliketorememberwhichuser@10.20.30.40 or maybe it was ssh someuserimashamedof@1.2.3.4 yes,