UNIX for Dummies Questions & Answers

I have a tab delimited file with 4 columns. If the value in the first column, equals the value in the second column, I'd like to have the 4th column multiplied by 2 then add 1. If the value in the first column differs from the value in the second, I'd like to have the 4th column multiplied by 2 only. How do I go about doing that? Thanks!

Example Input:

Code:

A A 1 2
A B 2 3 
A C 3 4

Example Output:

Code:

A A 1 5
A B 2 6
A C 3 8

Read all the fields into an array, do your math, print out the result. Adding the second dimension is left to the student.

DGPickett has it spot-on. I'd suggest giving the "awk" man page a thorough study and then write a suitable script for your problem.

Drum roll for the standard question:

What have you tried so far?

bakunin

I've tried :

Code:

 awk '$1!=$2' file1 | awk '{print $1,$2,$3,$4*2}' > file2
 awk '$1==$2' file2 | awk '{print $1,$2,$3,$4*2 + 1}' > file 3

It works but I was wondering if there is a way to convert them into a one liner

Code:

awk '$1!=$2{$4=$4*2}$1==$2{$4=$4*2+1}1' file

Pls pay full attention to DGPickett's and bakunin's comments, in order to improve your own skills!

Code:

$ awk '{$4=$4*2+($1==$2)}1' file
A A 1 5
A B 2 6
A C 3 8