This question already has an answer here:
simply put, I have a file with lines of text that are unknown to me, something like
abaa dddd bbbb cccc abaa aaaa abaa
the result I'd like to get is
dddd bbbb cccc aaaa
where all the duplicates are completely removed. if one line of text is duplicated anywhere else, remove this line and any repetitions that follow. is this possible to do? all of my searches show output with duplicates removed, leaving one instance, which I would like removed.