Linux, Unix, Operating Systems

QR Codes

QR Codes

QR codes are a two-dimensional equivalent of barcodes: a graphical encoding of information, which in practice means a string of about 4000 alpha-numeric characters (upper-case only) or a little less than 3000 arbitrary bytes.

So, how then are QR codes able to perform magic, such as automatically opening web pages, or sending text messages, or even dealing bitcoin? The answer is: they can’t.

Let’s try to understand what’s going on.

Read Again: The Art of UNIX Programming by Eric S. Raymond

In a moment of nostalgia, I picked up my copy of “The Art of UNIX Programming” by Eric S. Raymond (esr) and flipped through it again. It’s a book I’ve had since when it came out in 2004, and that I’ve always been quite fond of. I was looking forward to a review of “the way the future was”, as viewed from the early 2000s. So, it came as a bit of a surprise to me to find that the book seems to have aged rather poorly.

A Guide to Running GUI Applications in a Docker Container

Containers are not usually associated with GUI applications, but there may be times when one might still want to run such a program inside a container, for example to isolate the application’s dependencies. Installing a GUI application in a container means that not only the application, but also all its specific dependencies are encapsulated inside the container (respectively, the container image), and can therefore reliably be removed from the system in a single step.

The primary challenge is to let a container communicate with the host’s display system, so that it can create GUI windows on the host. A GUI application will likely also need to share files with the host system, which in turn requires the appropriate user permissions.