Terminate a frozen SSH session

I work remotely via a VPN and am often plagued by frozen SSH sessions (especially if I step away from my desk for any length of time).  I always used to close the shell/terminal - which is a bit annoying.  Then I came across the solution below, just type enter (in the frozen shell) then tilde and period/full-stop and you drop out of the ssh session.

Generating random numbers in bash

I wanted to assign each member of a training set to a cross-validation fold.  I wanted to do this in a bash script and so ended up using something like the following:

This script generates n numbers selected randomly in the series of integers from 1 to m.  In this case m represents the number of cross validation folds.


You could generate a random CV fold assignment like so:

Depending on your input file format of course.