Powershell 2.0 extract certain files from zip (include subdirectories)

Question

Apologies, this question is scattered on the internet but I have yet to find a satisfactory answer that uses only Powershell 2.0 (with .NET v3.5) - no external libraries or programs

I'm using the following code to extract log.txt from ZipFile.zip (no matter log.txt's location)

$Destination = (new-object -com shell.application).NameSpace('C:\ZipExtractDir')
$ZipFile = (new-object -com shell.application).NameSpace('C:\ZipFile.zip')

$Destination.CopyHere(($Zipfile.Items() | where-object {$_.Name -like '*log.txt'}), 1044)

• Works if log.txt is in directory root \log.txt
• Fails if log.txt is in a subdirectory \Subfolder\log.txt
• Fails if referencing the literal (.zip) path {$_.Name -Like '*Subfolder\log.txt'} (both double & single quotes fail)
• Have tried using -eq -like -contains '' "" $_.FullName

---

I'm quite certain that I'm filtering incorrectly - can anyone help with this code so that it will parse subdirectories as well?

Answer 1

Similar to what you have already done, you can set up the Shell.Application namespaces like this. Then you can copy the extracted directory to the destination path.

$zipFilePath = "Zipfile.zip"
$destinationPath = "C:\Users\Public\Downloads"

$zipfile = (New-Object -Com Shell.Application).NameSpace($zipFilePath)
$destination = (New-Object -Com Shell.Application).NameSpace($destinationPath)
$destination.CopyHere($zipfile.Items())

Then to list the log.txt files, we can contruct the full extracted path with Join-Path. This basically just appends the zip file name from System.IO.Path.GetFileNameWithoutExtension() to the destination path. Then just use Get-ChildItem to list the files recursively with the -Recurse and -Filter switches.

$extractedPath = Join-Path -Path $destinationPath -ChildPath ([System.IO.Path]::GetFileNameWithoutExtension($zipFilePath))
Get-ChildItem -Path $extractedPath -Filter log.txt -Recurse

And to test this for PowerShell 2.0 we can use -version 2 with powershell.exe:

powershell.exe -version 2 .\test.ps1

---

UPDATE

If you want to inspect files before extracting, you'll need to recurse the directories yourself. Below is a demo of how this can be done.

function New-ZipChildRootFolder 
{
    param 
    (
        [string]$DestinationPath,
        [string]$ZipFileName
    )

    $folderPath = Split-Path -Path $ZipFileName -Leaf

    $destination = (New-Object -ComObject Shell.Application).NameSpace($DestinationPath)

    $destination.NewFolder($folderPath)
}

function Get-ZipChildItems 
{
    param 
    (
        [string]$ZipFilePath,
        [string]$DestinationPath
    )

    $zipfile = (New-Object -ComObject Shell.Application).NameSpace($ZipFilePath)
    $zipFileName = [System.IO.Path]::GetFileNameWithoutExtension($ZipFilePath)

    Write-Output "Create root zip folder : $zipFileName"
    New-ZipChildRootFolder -DestinationPath $DestinationPath -ZipFileName $zipFileName

    foreach ($item in $zipFile.items()) 
    {
        Get-ZipChildItemsRecurse -Items $item -DestinationPath $DestinationPath -ZipFileName $zipFileName
    }
}

function Get-ZipChildItemsRecurse
{
    param 
    (
        [object]$Items,
        [string]$DestinationPath,
        [string]$ZipFileName
    )

    foreach ($file in $Items.getFolder.Items())
    {
        if ($file.IsFolder -eq $true) 
        {
            Write-Output "Creating folder : $($file.Path)"
            New-ZipChildFolder -Folder $file -DestinationPath $DestinationPath -ZipFileName $ZipFileName
            Get-ZipChildItemsRecurse -Items $file -DestinationPath $DestinationPath -ZipFileName $ZipFileName
        }
        else 
        {
            $filename = Split-Path -Path $file.Path -Leaf
            if ($filename -eq "log.txt")
            {
                Write-Output "Copying file : $($file.Path)"
                New-ZipChildFile -File $file -DestinationPath $DestinationPath -ZipFileName $ZipFileName
            }
        }
    }
}   

function New-ZipChildFile
{
    param
    (
        [object]$File,
        [string]$DestinationPath,
        [string]$ZipFileName
    )

    $destination = New-Object -ComObject Shell.Application

    $items = $File.Path.Split("\")

    $zipRootIndex = [array]::IndexOf($items, $ZipFileName)

    $path = $items[$zipRootIndex..($items.Length - 2)] -join "\"

    $fullPath = Join-path -Path $DestinationPath -ChildPath $path

    $destination.NameSpace($fullPath).CopyHere($File)
}

function New-ZipChildFolder
{
    param 
    (
        [object]$Folder,
        [string]$DestinationPath,
        [string]$ZipFileName
    )

    $destination = New-Object -ComObject Shell.Application

    $items = $Folder.Path.Split("\")

    $zipRootIndex = [array]::IndexOf($items, $ZipFileName)

    $folders = $items[$zipRootIndex..($items.Length - 1)]

    $currentFolder = $DestinationPath
    foreach ($folder in $folders)
    {
        $destination.NameSpace($currentFolder).NewFolder($folder)
        $currentFolder = Join-Path -Path $currentFolder -ChildPath $folder
    }
}

Usage:

$zipFilePath = "C:\Zipfile.zip"
$destinationPath = "C:\Users\Public\Downloads"

Get-ZipChildItems -ZipFile $zipFilePath -DestinationPath $destinationPath