Given two files, each containing a list of strings, in no particular order, find the list of strings that occur in both files. The output does not need to be in any particular order.
Even better if the output is in sorted order.
The original dataset is the dictionary file taken from Mac OS X Mojave (words).
Two randomly permuted subsets of this file (words.1 and words.2) have been generated, using the following commands:
shuf -n 140000 words > words.1
shuf -n 140000 words > words.2
The expected output (words.duped) has been generated using the following command:
cat words.1 words.2 | sort | uniq -d > words.duped