Your new project really could use a block device for Linux. File systems are easy to do with FUSE, but that’s sometimes too high-level. But a block driver can be tough to write and debug, especially since bugs in the kernel’s space can be catastrophic. [Jiri Pospisil] suggests Ublk, a framework for writing block devices in user space. This works using the io_uring facility in recent kernels.

This opens the block device field up. You can use any language you want (we’ve seen FUSE used with some very strange languages). You can use libraries that would not work in the kernel. Debugging is simple, and crashing is a minor inconvenience.

Another advantage? Your driver won’t depend on the kernel code. There is a kernel driver, of course, named ublk_drv, but that’s not your code. That’s what your code talks to.

The driver maintains the block devices and relays I/O and ioctl requests to your code for servicing. There are several possible use cases for this. For example, you could dream up some exotic RAID scheme and expose it as a block device that multiplexes many devices. The example in the post, for example, exposes a block device that is made up of many discrete files on a different file system.

Do you need this? Probably not. But if you do, it is a great way to push out a block driver in a hurry. Is it high-performance? Probably not, just like FUSE isn’t as performant as a “real” file system. But for many cases, that’s not a problem.

If you want to try FUSE, why not make your favorite website part of your file system?

If you were asked to pick the most annoying of the various Microsoft Windows interfaces that have appeared over the years, there’s a reasonable chance that Windows 8’s Metro start screen and interface design language would make it your choice. In 2012 the software company abandoned their tried-and-tested desktop whose roots extended back to Windows 95 in favor of the colorful blocks it had created for its line of music players and mobile phones.

Consumers weren’t impressed and it was quickly shelved in subsequent versions, but should you wish to revisit Metro you can now get the experience on Linux. [er-bharat] has created Win8DE, a shell for Wayland window managers that brings the Metro interface — or something very like it — to the open source operating system.

We have to admire his chutzpah in bringing the most Microsoft of things to Linux, and for doing so with such a universally despised interface. But once the jibes about Windows 8 have stopped, we can oddly see a point here. The trouble with Metro was that it wasn’t a bad interface for a computer at all, in fact it was a truly great one. Unfortunately the computers it was and is great for are handheld and touchscreen devices where its large and easy to click blocks are an asset. Microsoft’s mistake was to assume that also made it great for a desktop machine, where it was anything but.

We can see that this desktop environment for Linux could really come into its own where the original did, such as for tablets or other touch interfaces. Sadly we expect the Windows 8 connection to kill it before it has a chance to catch on. Perhaps someone will install it on a machine with the Linux version of .net installed, and make a better Windows 8 than Windows 8 itself.

Over the decades the number of Linux distributions has effectively exploded, from a handful in the late ’90s to quite literally hundreds today, not counting minor variations. There lately seems to be a counter-movement brewing in response to this fragmentation, with Project Bluefin’s Distroless project being the latest addition here. Also notable are KDE’s efforts, with KDE Linux as its own top-down KDE-based distro, but now with a switch to BuildStream from Arch likely as a distroless move.

It should be clear that there is no obvious course here yet, and that opinions are very much divided. The idea of ‘Linux’ becoming a more singular OS appeals to some, while to others it’s the antithesis of what ‘Linux’ is about. This much becomes clear in [Brodie Robertson]’s exploration of this topic as well.

The way to think about ‘distroless’ is that there is a common base using the Freedesktop SDK on which the customization layer is applied, such as Bluefin, KDE or Gnome’s environments. You could think of this base as the common runtime, using the Freedesktop standards for interoperability for a user-selected layer that’s installed on top. This way the idea of basing a distro on a specific distro is tossed out in favor of something that’s vaguely reminiscent of the Linux Standard Base attempt at standardization.

It’ll be fascinating to see how things will move from here, as there are definite arguments to be made in favor of less fragmentation and resultingly less duplicated effort. In many ways this would bring Linux closer to for example FreeBSD, which avoids the Linux Chaos Vortex problem by having a singular codebase. FreeBSD ‘distros’ like GhostBSD and NomadBSD are therefore essentially just specialized customizations that target a sub-group of FreeBSD users.

Of course, when we start talking about package managers and other base-distro specific features, we may very well risk igniting the same problems that tore apart the LSB so many years ago. Will we also standardize on RPM over DEB package files and kin, or something else?

I’m going to go ahead and admit it: I really have too many tray icons. You know the ones. They sit on your taskbar, perhaps doing something in the background or, at least, giving you fingertip access to some service. You’d think that creating a custom tray icon would be hard, but on Linux, it can be surprisingly simple. Part of the reason is that the Freedesktop people created standards, so you don’t typically have to worry about how it works on KDE vs. GNOME or any of the other desktop environments. That’s a big win.

In fact, it is simple enough that you can even make your own tray icons with a lowly shell script. Well, of course, like most interesting shell scripts, you need some helper programs and, in this case, we’ll use YAD — which is “yet another dialog,” a derivative of Zenity. It’s a GTK program that may cause minor issues if you primarily use KDE, but they are nothing insurmountable.

The program is somewhat of a Swiss army knife. You can use it to make dialogs, file pickers, color selectors, printer dialogs, and even — in some versions — simple web browsers. We’ve seen plenty of tools to make pretty scripts, of course. However, the ability to quickly make good-looking taskbar icons is a big win compared to many other tools.

Docs

Depending on what you want to do, YAD will read things from a command line, a file, or standard input. There are dozens of options, and it is, honestly, fairly confusing. Luckily, [Ingemar Karlsson] wrote the Yad Guide, which is very digestible and full of examples.

Exactly what you need will depend on what you want to do. In my case, I want a tray icon that picks up the latest posts from my favorite website. You know. Hackaday?

The Web Connection

YAD can render HTML using WebKit. However, I ran into immediate problems. The version in the repos for the Linux I use was too old to include the HTML option. I found a supposedly statically linked version, but it was missing dependencies. Even after I fixed that, the program still reported errors related to the NVIDIA OpenGL stack.

I quickly abandoned the idea of using a web browser. I turned to two other YAD features. First, the basic dialog can hold text and, in most cases, renders quasi-HTML because it uses the Pango library. However, there is also a text-info dialog built in. Unlike most other YAD features, the text-info dialog reads its input from standard input. However, it doesn’t render markup.

In the end, I decided to try them both. Why not? It is simple enough. But first, I needed a tray icon.

The Tray

YAD can provide a “notification,” which is what it calls a tray icon. You can specify an icon, some text, and a right-click context menu. In addition, it can react when someone clicks on the icon.

I decided to write a script with multiple personalities. If you run it with no arguments, it sets up the tray icon. If you pass anything to it, it will show a dialog with the latest Hackaday articles from the RSS feed. I wanted to make those links clickable, and that turned out to be a bit of a wrinkle. Both versions will do the job, but they each need a different approach, as you will see.

Here’s the tray code:

yad --notification --image="$0.icon.png" --text="Hackaday Now" \
   --menu="Quit!quit!gtk-quit" --command="$0 show" --no-middle

You can probably guess at most of this without the manual. The image is stored in a file with the same name as the script, but with .icon.png at the end. That’s the icon in the tray. The simple menu provides an option to exit the program. If you click the icon, it calls the same script again, but with the “show” argument. The script doesn’t care what the argument is, but maybe one day it will.

So that part of the project was extremely simple. The next job is making the dialog appear.

Text Info

Grabbing the RSS feed with wget is trivial. You could use grep, sed, and bash pattern replacement to extract the titles and URLs, but I opted for awk and a brute-force parsing approach.

The standard output of awk pipes into YAD, but you can’t readily apply formatting or hyperlinks. You can use formatting in regular dialog text, which will appear before the other output. That’s where the yellow “Hackaday Today!” title in the adjacent screenshot gets set. In addition, you can automatically detect URLs and make them clickable using the --show-uri option.

Here’s the relevant command:

yad --text-info \
   --text "<span foreground='$TITLECOLOR'><b><big><big>Hackaday Today!</big></big></b></span>" \
   --show-uri --window-icon="$0.icon.png" \
   --uri-color=$LINKCOLOR --width=$WIDTH --height=$HEIGHT \
   --Title "Hackaday Posts" --button="Close!gtk-ok" \
   --buttons-layout=center --escape-ok 2>/dev/null

You’ll notice that the –text option does take Pango formatting and the --show-uri option makes the links clickable. By default, dialogs have an Open and Cancel button, but I forced this one to have a single close button, accept escape, and I wanted the button centered.

As you can see in the screenshot, the result isn’t bad, but it does require having the title followed by a long URL that you can click on and that’s a little ugly.

Stock Dialog

Since the –text option works with any dialog and handles formatting, I decided to try that. The awk code was nearly the same, except for the output formatting. In addition, the output now needs to go on the command line instead of through a pipe.

This does make the script a bit more unwieldy. The awk script sets a variable, since jamming the command into the already busy YAD command line would make the script more complicated to read and work with.

The YAD command is still simple, though:

yad \
--text="$DATA" \
--window-icon="$0.icon.png" \
--width=$WIDTH --height=$HEIGHT \
--Title "Hackaday Posts" --button="Close!gtk-ok" \
--buttons-layout=center --escape-ok

The DATA variable has the formatted output text. The result looks better, as you can see in the screenshot. In either version, if you click an underlined link, your default browser should open the relevant post.

Other Choices

If you want to install either script, you can get it from GitHub. Of course, you could do this in Python or any other conventional language. There are also programs for “minimizing” another program to the tray, like AllTray or KDocker, although some of these may only work with X11 and not Wayland.

It would have been nice to have an integrated browser, although, thanks again to FreeDesktop, it is simple enough to open a URL and launch the system’s default browser.

Prefer your Hackaday feed on the command line? Check out the comments for this post. Meanwhile, send us a tip (you know, a link to your project, not a gratuity) and maybe you’ll see your own project show up on the feed.