How to compare files in two .zip folder in Windows PowerShell

Question

I can compare files in two different folder with the commands:

$test = get-childitem -recurse -path C:\test 
$test1 = get-childitem -recurse -path C:\test1
$counter = (diff $test $test1).count

I would like to know how many differences between those two folders. This works.

However, now I would like to compare the filenames in two .zip files. Is it possible to compare the files inside two .zip files and I get a return value for the counter of different files? Thank you so much.

Answer 1

I have tested .NET ZIP functionality on PowerShell V4. I suspect it would work on V3 but not on V2 (or V1).

Add-Type -AN System.IO.Compression.FileSystem
$zip1 = [IO.Compression.ZipFile]::OpenRead("c:\test\test1.zip")
$zip2 = [IO.Compression.ZipFile]::OpenRead("c:\test\test2.zip")
$names1 = $zip1.Entries.FullName
$names2 = $zip2.Entries.FullName
$counter = (diff $names1 $names2).count
$zip1.Dispose()
$zip2.Dispose()