Unzip a file in powershell by overwriting existing files

unzip.ps1

function Unzip($zipfile, $outdir)
{
    Add-Type -AssemblyName System.IO.Compression.FileSystem
    $archive = [System.IO.Compression.ZipFile]::OpenRead($zipfile)
    foreach ($entry in $archive.Entries)
    {
        $entryTargetFilePath = [System.IO.Path]::Combine($outdir, $entry.FullName)
        $entryDir = [System.IO.Path]::GetDirectoryName($entryTargetFilePath)
        
        #Ensure the directory of the archive entry exists
        if(!(Test-Path $entryDir )){
            New-Item -ItemType Directory -Path $entryDir | Out-Null 
        }
        
        #If the entry is not a directory entry, then extract entry
        if(!$entryTargetFilePath.EndsWith("\")){
            [System.IO.Compression.ZipFileExtensions]::ExtractToFile($entry, $entryTargetFilePath, $true);
        }
    }
}

Unzip -zipfile "$zip" -outdir "$dir"

If the zip was created on a Unix system, you want to amend the check for directory to the following:

if (!$entryTargetFilePath.EndsWith("\") -And !$entryTargetFilePath.EndsWith("/")) {