How do I find all the lines that are in one file and not in another?

Question

Say I got:

aaa
bbb
ccc

and:

aaa
ccc
ddd

and I would like:

bbb

How would I get it?

I guess this has been asked many times. I cannot find an exact duplicate, though! — fedorqui, May 26 '14 at 12:28
It looks like it should have been, but I couldn't find anything helpful. — John Lawrence Aspden, May 26 '14 at 12:30
possible duplicate of [bash, Linux: Set difference between two text files](http://stackoverflow.com/questions/2509533/bash-linux-set-difference-between-two-text-files) — msw, May 26 '14 at 13:10

anubhava · Accepted Answer · 2014-05-26T13:05:28.747

2

Using grep -vf:

grep -vFxf file2 file1
bbb

edited May 26 '14 at 13:05

answered May 26 '14 at 12:20

anubhava

looks like it should work but it's horribly slow on my actual fairly moderate (1MB) files. – John Lawrence Aspden May 26 '14 at 12:29
You can add `-F` and `-x` options for fixed + exact matching, but I guess it will make it even slower. – fedorqui May 26 '14 at 12:30
grep -vFxf is very fast and does what I wanted. Gracies, el amic. – John Lawrence Aspden May 26 '14 at 12:38

score 0 · Answer 2 · edited May 26 '14 at 15:18

0

Please try below command:

comm is used for Compare sorted files FILE1 and FILE2 line-by-line.

-23 suppresses column 2 and 3.

$ comm -23 fil1.txt fil2.txt  
bbb

edited May 26 '14 at 15:18

fedorqui

answered May 26 '14 at 13:08

Ayyappa Boligala

2 Answers2