Hi all,
I want to compare two files based on column value
Kindly help me
a.txt
123,ABCD
456,DEF
789,SDF
b.txt
123,KJI
456,LMN
321,MJK
678,KOL
Output file should be like
Common on both files
c.txt
123,ABCD,KJI
456,DEF,LMN
Present in one file but not in 2nd file
789,SDF
Present in 2nd file but not in first file
321,MJK
678,KOL
What have you tried?
I tried using join and awk both but didnt work
I have only basic knowledge of awk 
In what way did it "not work"? Show exactly what you did, and we can help correct your mistakes.
join -t, -o "1.1 1.2 2.2" a b
Thank you.
join requires sorted input, so isn't suitable here.
How about this:
$ awk -F, '{ A[$1]=A[$1] FS $2 ; T[$1]++ } END { for(X in T) if(T[X]>1) { print X A[X] } }' a.txt b.txt
456,DEF,LMN
123,ABCD,KJI
$
can you pls revert for other two requirement as well
Requirement? Is this homework?
Try this:
awk -F, '
NR==FNR{a[$1]=$0;next}
$1 in a{print a[$1] FS $2; delete a[$1];next}
{print > "e.txt"}
END {for(i in a){print a > "d.txt"}}' a.txt b.txt > c.txt