Since we dont have uniq
Here is it, and it doesnt even need a sort
Basically it goes line by line and only prints it if it hasnt been seen
cat text.txt | awk '!a[$0]++'
cat text.txt | awk '!a[$0]++'
cat text.txt | awk '!a[$0]++'
If you want to sort the output afterwards (sort by frequency of occurrence)
cat text.txt | awk '!a[$0]++' | sort
cat text.txt | awk '!a[$0]++' | sort
cat text.txt | awk '!a[$0]++' | sort
The end.