I have something like this
file1:
element1,12
element2,10
element3,5
file2:
IN
element1,8
element3,5
and I want to modify file1 and obtain:
element1,20
element2,10
element3,10
The first line from file2 contains "IN" that, means I want to make an addition. If it would have been "OUT" instead, the values should be subtracted and file1 should have looked like this:
element1,4
element2,10
element3,0
I have to work with awk, grep, sed. Thx a lot!