Compare two files

Shell Programming and Scripting
1

I need to compare two files and output the new lines added & updates made to existing lines to a different files based on a key.

File1: (old file)
-----------------------------------------

1, abcd, 1, a, 1
2, abcd, 2, b, 2
3, bcd,  3, c, 3

File 2: (new file)
---------------------------

1, abcd, 1, a, 1
2, bcde, 4, b, 2
3, bcda, 3, d, 5
4, aard,  5, f, e

The First Column in both the files in the common primary key to look for.

Outputs Needed:
---------------------
1)NewLineAdded.txt
--------

4, aard,  5, f, e

2) UpdatedLines.txt
-------------------

2, bcde, 4, b, 2
3, bcda, 3, d, 5
2

One way..

awk -F, 'NR==FNR{a[$1]=$2$3$4$5;next} {if ($1 in a) {if(a[$1] != $2$3$4$5){print $0 > "updated"}} else {print $0 > "new"}  }' old_file new_file

awk -F, '
	NR==FNR {a[$1]=$2$3$4$5;next}
	{
		if ($1 in a) {
			if(a[$1] != $2$3$4$5) {print $0 > "updated"}
		} else {
			print $0 > "new"
		} 
	}' old_file new_file