Randomly select a line out of a text file and set that line as a variable

Question

How to randomly select a line/ip out of a text file, and set it as a variable.

I mean something like:

set IP=TheLine/IPFromOfTheFile

Answer 1

My solution is essentially identical to Aacini's but with a few differing details:

@echo off

setlocal enabledelayedexpansion
set i=0
for /f "tokens=*" %%x in (%1) do (
    set line[!i!]=%%x
    set /a i += 1
)
set /a j=%random% %% %i%
set ip=!line[%j%]!

The file name is an argument to this batch.