2012 Scripting Games Beginner Event 4: Compare Two Folders

Or “My first 5 star script”

The scenario in this event was to compare 2 the contents of 2 folders to make sure that the files where being copied across successfully. The full scenario is listed here

The design points are listed below and quite easy to fulfil.

• You should return file information objects as the result of your comparison.
• You only need to compare file names, not file sizes, dates, or contents.
• Your output should list files that exist in one folder, but not in the other folder.
• Because the object is to prove to your boss that your backup works, you do not need to write a complicated script. Unnecessary complexity will cost you points.
• Extra points for using native Windows PowerShell cmdlets, and for simplicity of code.

The cmdlet we need for this is

Compare-Object

Now we need to add in the reference and difference objects

Compare-Object -ReferenceObject C:\2 -DifferenceObject C:\1

This will only show that folders 1 and 2 are different, so what we need to do is get the contents of the folder

Compare-Object -ReferenceObject (Get-ChildItem C:\2)
 -DifferenceObject (Get-ChildItem C:\1)

(Get-ChildItem C:\2) will process the contents of the folder before comparing them. This gets around having to create a variable and making the script unnecessarily complex.

Finally we add in the –PassThru to pass through the output to the console

Compare-Object -ReferenceObject (Get-ChildItem C:\2) 
-DifferenceObject (Get-ChildItem C:\1) –PassThru

 

And there is my 5 star script for Beginner Event 4 of the 2012 Scripting Games