UNIX for Dummies Questions & Answers

super newbish question here. I have a file with the following format:

Code:

A  A  200
A  B  100
A  C  90
B  B  203
B  A  101
B  C  87
C  C  300
C  A  91
C  B  86

I would like to find reciprocal sets for columns 1 and 2 and then write the value of column 3 for the reciprocal set into column 4.

An example:

The second row "A B" has a reciprocal set, which is row 5 "B A"

So, I would like to make a script that would output for row 2:

Code:

A  B  100  101

obvious some columns would not have reciprocals in which case I would like the 4th row to be 0.

Is this possible?

cheers!