Background

I have five files that I am trying to make unique relative to each other. In other words, I want to make it so that the lines of text in each file have no commonality with each other.

Attempted solution

So far, I have been able to run the grep -vf command comparing one file with the other 4 as so:

grep -vf file2.txt file1.txt

grep -vf file3.txt file1.txt

…

This makes it print out the lines in file1 that are not in file2, nor file3, etc.. However, this becomes cumbersome because I would need to do this for the superset of all files. In otherwords, to truly reduce each file to lines of text only in that file, I would have to do every combination of files into the grep -vf command. Given that this sounds cumbersome to me, I wanted to know…

Question

What is the command/series of commands in linux to find the lines of text in each file that is mutually exclusive to all the other files?

Answer

You could just do:

awk '!a[$0]++ { out=sprintf("%s.out", FILENAME); print > out}' file*

This will write the lines that are uniq in file to file.out. Each line will be written to the output file of the associated input file in which it first appears, and subsequent duplicates of that same line will be suppressed.