diff on columns of two files in shell

Question

I want to do a very simple thing. I have two files as follows:

FILE 1:
A s1 p1
B s2 p2
C s3 p3

FILE2:
B s4 p4
A s1 p1
C s6 p6

I want to extract first and third column from both file and print diff of that file. One easy way is to create intermediate files with cut -f1,3 of both files and do diff. Thats what exactly i want my output is. But i don't want to create intermediate file. Any simple one liner to do that.

One more thing, both the files are NOT sorted, so unable to use join directly.

Answer 1

Try this:

diff <(cut -f1,3 file1) <(cut -f1,3 file2)

References:

Compare two files line by line and generate the difference in another file

Answer 2

Use [ process substitution ]

diff -y <( awk '{print $1,$3}' file1) <( awk '{print $1,$3}' file2 )

should do it. Note -y option with diff is for side-by-side o/p.