Linux comm command

http://www.unixcl.com/2009/08/linux-comm-command-brief-tutorial.html


From COMM(1) man page, the options available are:

-1 suppress lines unique to FILE1
-2 suppress lines unique to FILE2
-3 suppress lines that appear in both files

comm - compare two sorted files line by line

comm <(sort a.txt) <(sort b.txt)