SO what is the one-line command and how do I know if my computer is in jeopardy?
The means for triggering the flaw are in the article.
If you're running Windows XP or later up to and including the latest Windows 10, your computer is vulnerable to this corruption.
That said, it's not going to suddenly corrupt itself -- you or a bad guy would have to do it intentionally. So: 1) don't execute the command that does it, and b) secure your system to be as safe as possible from bad guys.
I assume you know how to do the latter. If not, and you're running Windows, I recommend that you start learning quick. :-)