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.
This has similar benefits — and drawbacks — to a normal cloud service. Invocation is simple. To get the current weather, for example:
curl wttr.in
Produces this:
You can, of course, pass arguments to set a different location and other options.
Some of the tools have pretty impressive graphics outputs for console tools. Of course, there’s nothing magic about curl. You can easily use something like wget if you arrange for its output to go to the console.
[Igor] has promised a framework is forthcoming to help create these kinds of services. Honestly, we could just as easily see using any of a dozen other protocols to do the same thing and unless there is a compelling reason to have things on the cloud, we aren’t sure these services are particularly great other than as examples. But we can see using the technique to serve centralized data out to terminal sessions, for example. As an example of what other protocols can do, try this:
telnet towel.blinkenlights.nl
[Igor] doesn’t have a monopoly on curl-friendly services like this. Try:
curl http://ifconfig.co
If you are a big fan of the command line, why not put one on your Arduino? If you start juggling lots of commands, maybe checkout Marker.
Source:: Hackaday