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:

rename file "input.txt" to "output.txt"
rename folder "docs" to "mydocs"
rename file "/input.txt" to "/output.txt"
rename folder "/docs" to "/mydocs"