Problem Statement

Rename:

This should be done twice:   once "here", i.e. in the current working directory and once in the filesystem root. It can be assumed that the user has the rights to do so. (In unix-type systems, only the user root would have sufficient permissions in the filesystem root.)

Let's start with the solution:

# Here
File.rename('input.txt', 'output.txt');
File.rename('docs',      'mydocs');

# Root dir
File.rename(Dir.root + %f'input.txt', Dir.root + %f'output.txt');
File.rename(Dir.root + %f'docs',      Dir.root + %f'mydocs');