Question

I need to process two file contents. I was wondering if we can pull it off using a single nawk statement.

File A contents:

AAAAAAAAAAAA  1
BBBBBBBBBBBB  2
CCCCCCCCCCCC  3

File B contents:

XXXXXXXXXXX  3
YYYYYYYYYYY  2
ZZZZZZZZZZZ  1

I would like to compare if $2 (2nd field ) in file A is the reverse of $2 in file B.
I was wondering how to write rules in nawk for multi-file processing ?
How would we distinguish A’s $2 from B’s $2

EDIT: I need to compare $2 of A’s first line (which is 1) with the $2 of B’s last line (which is 1 again) .Then compare $2 of line 2 in A with $2 in NR-1 th line of B. And so on…..

Answer 1

You can do something like this –

[jaypal:~/Temp] cat f1
AAAAAAAAAAAA  1
BBBBBBBBBBBB  2
CCCCCCCCCCCC  3
DDDDDDDDDDDD  4

[jaypal:~/Temp] cat f2
AAAAAAAAAAA  5
XXXXXXXXXXX  3
YYYYYYYYYYY  2
ZZZZZZZZZZZ  1

Solution:

awk '
NR==FNR {a[i++]=$2; next}
{print (a[--i] == $2 ? "Match " $2 FS a[i] : "Do not match " $2 FS a[i])}' FileB FileA
Match 1 1
Match 2 2
Match 3 3
Do not match 4 5