Hmmm. Readme unfortunately fails to note what the required hardware is (that apparently has a common/shared control interface) which makes these USB hubs controllable.
What? They list several hubs that work, I guess you could buy any of these.

https://github.com/codazoda/hub-ctrl.c#hubs-known-to-work

In my experience, the hubs listed tend to be obsolete. For instance, that LinkSys one I just looked up and its manual is copyright 15 years ago.

Someone on Amazon is boldly offering to sell you one, a 4 port USB 2.0 hub, for $72, but whether they actually have it or are a robot planning to order one from another robot that doesn’t have it but thinks it can get it for $60 is anyone’s guess.

Last time I went through hubctl’s list, none were available new, and lots of the ones listed have “issues” where later buyers can’t make them work (probably because the manufacturer changed the design but kept the model number). But that’s been a few years.

I just like to tell the manufacturers that I’m a niche, but I will happily pay double for them to put the current sense shunts and power switching transistors from the IC reference design on their board.

Also listed elsewhere, this repo has a much more up to date list. Maybe I should make an edit to the repo after all these years!

I also had trouble finding the original author online when I created the GitHub repo, but the other repo links him. I’m sure this didn’t exist back in the day. I did reach out to Niibe Yutaka way back and get his permission to post on GitHub.

https://github.com/mvp/uhubctl