comm est la commande qu'il te faut

COMM(1) NetBSD General Commands Manual COMM(1)

NAME
comm -- select or reject lines common to two files

SYNOPSIS
comm [-123f] file1 file2

DESCRIPTION
The comm utility reads file1 and file2, which should be sorted lexically,
and produces three text columns as output: lines only in file1; lines
only in file2; and lines in both files.

The filename ``-'' means the standard input.

The following options are available:

-1 Suppress printing of column 1.

-2 Suppress printing of column 2.

-3 Suppress printing of column 3.



Pour que ca marche, il faut que les fichiers soient triés.

droopy# cat A
1
2
4
A
S

droopy# cat B
4
S
X
3
2
1droopy# sort A >A.sorted
droopy# cat ./A.sorted
1
2
4
A
S
droopy# sort B >B.sorted
droopy# cat ./B.sorted
1
2
3
4
S
X

droopy# comm -13 ./A.sorted ./B.sorted
3
X

droopy# comm -23 ./A.sorted ./B.sorted
A