Comparing two lists [SOLVED (at least it looks like that)]

[Rolf Nielsen]

2011-05-07 02:09, Rolf Nielsen skrev:
> Hello all,
>
> I have two text files, quite extensive ones. They have some lines in
> common and some lines are unique to one of the files. The lines that do
> exist in both files are not necessarily in the same location. Now I need
> to compare the files and output a list of lines that exist in both
> files. Is there a simple way to do this? diff? awk? sed? cmp? Or a
> combination of two or more of them?
>
> TIA,
>
> Rolf

sort file1 file2 | uniq -d