extracting unique values between 2 sets/files

Question

Working in linux/shell env, how can I accomplish the following:

text file 1 contains:

1
2
3
4
5

text file 2 contains:

Answer 1

Using some lesser-known utilities:

sort file1 > file1.sorted
sort file2 > file2.sorted
comm -1 -3 file1.sorted file2.sorted

This will output duplicates, so if there is 1 3 in file1, but 2 in file2, this will still output 1 3. If this is not what you want, pipe the output from sort through uniq before writing it to a file:

sort file1 | uniq > file1.sorted
sort file2 | uniq > file2.sorted
comm -1 -3 file1.sorted file2.sorted

There are lots of utilities in the GNU coreutils package that allow for all sorts of text manipulations.

Answer 2

with grep:

grep -F -x -v -f file_1 file_2