Terminal command

A few days ago I was having issues with audible books. It was late and I found a thread on Apple forums and one suggestion was running this terminal command :

{ sudo chflags -R nouchg,nouappnd ~ $TMPDIR..; sudo chown -R $UID:staff ~ $_; sudo chmod -R u+rwX ~ $_; chmod -R -N ~ $_; } 2>&-

Nothing bad has happened but I stupidly ran it not knowing the consequences ( never again )

Anyone familiar with terminal commands tell me what exactly it's done. I was concerned it may have been a ruse to open up some security etc