This year I was competing in the Windows PowerShell Scripting Games 2012.
One of the exercises in the Beginners class was to compare two folders.
Ed Wilson (Microsoft ScriptingGuy) provided a script to create two folders with a bunch of files in them and delete one file from each folder.
So, I started to script… by using the Compare-Object cmdlet. This lets you compare objects (sounds kinda logical when looking at the name of the cmdlet, right? Image may be NSFW.
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).
But, then there was the Expert Commentary… here the expert provided explanation of the exercise and the solution. The solution he provided was as follows:
$original = Get-Childitem -Path c:\1 | Sort-Object -Property Name
$copy = Get-Childitem -Path c:\2 | Sort-Object -Property Name
$difference = @(Compare-Object -ReferenceObject $original -DifferenceObject $copy -Property Name -PassThru)
if ($difference.Count -eq 0) {
Write-Host -ForegroundColor Green ‘Content is equal’
} else {
Write-Host -ForegroundColor Red ‘Content is different. Differences:’
$difference
}
Now, this is a easy and good solution Image may be NSFW.
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In short (by removing code that’s not required for the functionality of the script), this will become something like:
$original = Get-Childitem -Path c:\1 | Sort-Object -Property Name
$copy = Get-Childitem -Path c:\2 | Sort-Object -Property Name
$difference = @(Compare-Object -ReferenceObject $original -DifferenceObject $copy -Property Name -PassThru)
This differs from the solution I came up with since I’m a big fan of “one liners” Image may be NSFW.
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My solution:
Compare-Object –ReferenceObject (Get-ChildItem C:\1) –DifferenceObject (Get-ChildItem C:\2) –Passthru
Now, yesterday one of my students (in a PowerShell workshop I’m giving) came up with an even shorter solution (and I was thinking my solution was bad-ass Image may be NSFW.
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Compare-Object (Get-Childitem C:\1) (Get-ChildItem C:\2)
This is because Compare-Object automatically knows that if you provide the objects, the first is the ReferenceObject and the second will be the DifferenceObject… so even an easier way Image may be NSFW.
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Now this is the strength of PowerShell… it’s very easy, short, intelligent and understandable… but you can still make it as complex as you want Image may be NSFW.
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