uninstall - What's the name of PPA? (for ppa-purge)

I'm testing PPAs, so I commonly use ppa-purge, that restores my default versions. But I always have problem with the ppa name. What do I need to put as argument for ppa-purge?

I always used my browser to check name on launchpad, but what about when I'm without internet and I can't start X. Org server?

For xorg-edgers I know that ppa:xorg-edgers/ppa what about others? Let's say, I know that I have PPA of X-Updates. How do I find out the name of this PPA so I could use with ppa-purge, without using browser

So the name should be something like ppa:NAME/ppa? How to get this NAME?

This command will list all the PPA repositories you have configured

grep ppa /etc/apt/sources.list /etc/apt/sources.list.d/*

Alternatively, you can check the repository of a given package

apt-cache policy [package-name]