How to sort by column and break ties randomly

Question

I have a tab-delimited file with three columns like this:

joe W 4
bob A 1
ana F 1
roy J 3
sam S 0
don R 2
tim L 0
cyb M 0

I want to sort this file by decreasing values in the third column, but to break ties I do not want to use some other column to do so (i.e. not use the first column to sort rows with the same entry in the third column).

Instead, I want rows with the same third column entries to either preserve the original order, or be sorted randomly.

Is there a way to do this using the sort command in unix?

Answer 1

For the first part, you can use the -k option of sort :

sort -k 3 -r

I don't really understand what you want to do with ties...