Using diff and erasing the lines that match
 

How do I diff two files and erase the lines that are the same without having to go into an editor?

So if i have

List A
1
2
3
4
5
6

List B
2
4
6

If i diff these two files, i'd want to be able to have
List A -B = C

List C
1
3
5

Pipe is your friend. Also check sed and awk as they would be helpfull.

I think something like "diff list_A list_B > list_C" would work.

No, that would just get me output of the diff...i want to actually get rid of any lines that match in List B.

Hi,

Using one command:

comm -3 list_A list_B

man comm for details.

Hope this helps.

That is exactly what I was looking for. THANKS!