You just look for people who are interested to learn your language, any place where people communicate can work. Maybe hit some groups for learning the language you know and try to find people who speak the language you want there.
I personally play VRChat, there are a number of language learning groups there. Though, the culture of the place is certainly not for everyone.
Not really about piracy, but doing language exchanges is a great way to learn a language. You teach someone your language, they teach you theirs. It’s free and it gives you more knowledge than any book. Natural languages don’t work with strict rules usually, natives speak by feel, the only way to learn that feel is by interacting with people.
Assuming you made a bit of a typo with your regexp, any of these should work as you want:
grep -oE '/dev/loop[0-9]+'
awk 'match($0, /\/dev\/loop[0-9]+/) { print substr($0, RSTART, RLENGTH) }'
sed -r 's%.*(/dev/loop[0-9]+).*%\1%'
AWK one is a bit cursed as you can see. Such ways of manipulating text is not exactly it’s strong suite.
That’s exactly why you want to do this. When people speak casually or are making jokes, nobody speaks with grammar in mind. Gathering this intuition for the language is exactly what I’m looking for when learning.