It is no secret that most Linux power users use the shell for many tasks, as for people who know what they are doing, it can be quite efficient. In addition, there are some tasks that can only be carried out from the command line, although their number shrinks every year. However, these days we are spoiled because you can have one X session running lots of terminals at once. If you log into a server, it might not have X. Or you might log into a computer over a slow connection where X is painful to use. What then? The modern answer is the tmux terminal multiplexer, and [zserge] has a thoughtful introduction to how you can use tmux for improved productivity at the command line.
In particular, he shares some configuration and offers sound advice. For example, do you really need a status bar that shows you CPU load at all times? Cool, yes, but not always a practical win.
Continue reading “Linux Command Line Productivity With Tmux”
There are countless ways to create music. In the simplest form, it won’t even require any equipment, as evidenced by beatboxing or a capella. If we move to the computer, it’s pretty much the same situation: audio programming languages have been around for as long as general-purpose high-level languages, and sound synthesis software along with them. And just as with physical equipment, none of that is particularly necessary thanks to
sed. Yes, the
sed, the good old stream editor, as [laserbat] shows in her music generating script.
Providing both a minified and fully commented version of Bach’s Prelude 1 in C major as example, [laserbat] uses a string representation of the sheet music as the script’s starting point, along with a look-up table of each transformed note’s wavelength. From here, she generates fixed length PCM square wave signals of each of the notes, to be piped as-is to the sound card via ALSA’s
aplay or SoX’s
play. To keep things simple enough, she stays within the region of printable characters here, using space and tilde as low and high values respectively, providing highest possible volume at the same time this way.
The concept itself is of course nothing new, it’s how
.wav files work, as well as these little C lines. And while the fixed note duration takes away some of the smoothness in [laserbat]’s version, adding variable duration might just be a hint too much for a
sed implementation, although we’ve certainly seen some more complex scripts in the past.
The ARM series of processors are an industry standard of sorts for a vast array of applications. Virtually anything requiring good power or heat management, or any embedded system which needs more computing power than an 8-bit microcontroller is a place where an ARM is likely found. While they do appear in various personal computers and laptops, [Pieter] felt that their documentation for embedded processors wasn’t quite as straightforward as it could be and created this development board which will hopefully help newbies to ARM learn the environment more easily.
Called the PX-HER0, it’s an ARM development board with an STM32 at its core and a small screen built in. The real work went in to the documentation for this board, though. Since it’s supposed to be a way to become more proficient in the platform, [Pieter] has gone to great lengths to make sure that all the hardware, software, and documentation are easily accessible. It also comes with the Command Line Interpreter (CLI) App which allows a user to operate the device in a Unix-like environment. The Arduino IDE is also available for use with some PX-HER0-specific examples.
[Pieter] has been around before, too. The CLI is based on work he did previously which gave an Arduino a Unix-like shell as well. Moving that to the STM32 is a useful tool to have for this board, and as a bonus everything is open source and available on his site including the hardware schematics and code.
Git is a handy tool that many of us are using for more than just software development. Having a cloud-based upstream repository is also surprisingly useful, but until now using GitHub — the most common upstream server — meant firing up a web browser, at least for certain tasks. Now GitHub is releasing a beta version of command-line tools made to manipulate your GitHub repos.
The tools are early release so they mostly focus on issues and pull requests. Of course, git itself will do the normal things like clone and checkout — you’ve always been able to do that on the command line. The example given in the announcement blog post lists all issues with a help wanted label:
gh issue list --label "help wanted"
We noticed that asking to view the issue, while done on the command line, will still open a browser. The tools are still a little early, so this is an excellent time to let the developers know what you’d like or otherwise influence the project.
We were a little surprised it wouldn’t just consume git, so that you’d use the same commands for everything and it would just pass pre-formed commands to git. Of course, that would be pretty easy to write as a shell script wrapper if you were interested in such a thing.
You’d be forgiven for only thinking of git as a way to manage source code revisions, but it’s actually capable of all sorts of interesting tricks.
Not every programmer likes creating GUI code. Most hacker types don’t mind a command line interface, but very few ordinary users appreciate them. However, if you write command line programs in Python, Gooey can help. By leveraging some Python features and a common Python idiom, you can convert a command line program into a GUI with very little effort.
The idea is pretty simple. Nearly all command line Python programs use
argparse to simplify picking options and arguments off the command line as well as providing some help. The Gooey decorator picks up all your options and arguments and creates a GUI for it. You can make it more complicated if you want to change specific things, but if you are happy with the defaults, there’s not much else to it.
At first, this article might seem like a Python Fu and not a Linux Fu, since — at first — we are going to focus on Python. But just stand by and you’ll see how this can do a lot of things on many operating systems, including Linux.
Continue reading “Linux Fu: Python GUIs For Command Line Programs (Almost) Instantly”
Although many people think of Linux-based operating systems as graphical, really that GUI is just another application running over the bare operating system. Power users, remote administrators, and people running underpowered computers like a Raspberry Pi have a tendency to do more with command line tools. [Igor] did a FOSDEM19 presentation you can see below about how he’s providing web-like services to the command line using web servers and curl as a client.
This is subtly different from just accessing an ordinary web server via curl. The output is meant for display in the terminal. Of course, you could also hit them with a web browser, if you wanted — at least, for some of them. [Igor’s] tools include a weather reporter, a QR code encoder, information and graphs for currency and cybercurrency rates, and an online help system for programmers.
Continue reading “Command Line Utilities… In The Cloud?”
When using an Arduino, at least once you’ve made it past blinking LEDs, you might start making use of the serial connection to send and receive information from the microcontroller. Communicating with the board while it’s interacting with its environment is a crucial way to get information in real-time. Usually, that’s as far as it goes, but [Pieter] wanted to take it a step farther than that with his command line interpreter (CLI) for the Arduino.
The CLI allows the user to run Unix-like commands directly on the Arduino. This means control of GPIO and the rest of the features of the microcontroller via command line. The CLI communicates between the microcontroller and the ANSI/VT100 terminal emulator of your choosing on your computer, enabling a wealth of new methods of interacting with an Arduino.
The CLI requires a hex file to be loaded onto the Arduino that you can find at a separate site, also maintained by [Pieter]. Once that’s running, you can get all of that sweet command line goodness out of your Arduino. [Pieter] also has some examples on his project page, as well as the complete how-to to get this all set up and running. There’s a lot going on in the command line world, in Linux as well as windows. So there’s plenty to explore there as well.