Expand-GzipFile.ps1

Function Expand-GZipFile {
    <#
.Synopsis
    Unzip a gz file
.Description
    Unzip a gz file
.Notes
    Change History
    1.0 | 2019/03/22 | francois-xavier cat (@lazywinadmin)
        based on https://social.technet.microsoft.com/Forums/windowsserver/en-US/5aa53fef-5229-4313-a035-8b3a38ab93f5/unzip-gz-files-using-powershell?forum=winserverpowershell
        add comment based help, error handling, missing parameters
        rename variables
.Example
    Expand-GZipFile -LiteralPath C:\tmp\lazywinadmin-2019.xml.gz -outfile C:\tmp\lazywinadmin-2019.xml

    Will expand the content of C:\tmp\lazywinadmin-2019.xml.gz to C:\tmp\lazywinadmin-2019.xml

.Example
    Expand-GZipFile -LiteralPath C:\tmp\lazywinadmin-2019.xml.gz

    Will expand the content of C:\tmp\lazywinadmin-2019.xml.gz to C:\tmp\lazywinadmin-2019.xml
.LINK
        https://github.com/lazywinadmin/PowerShell
#>
    [CmdletBinding()]
    Param(
        [ValidateScript( { Test-Path -Path $_ })]
        [String]$LiteralPath,
        $outfile = ($LiteralPath -replace '\.gz$', '')
    )
    try {
        $FileStreamIn = New-Object -TypeName System.IO.FileStream -ArgumentList $LiteralPath, ([IO.FileMode]::Open), ([IO.FileAccess]::Read), ([IO.FileShare]::Read)
        $output = New-Object -TypeName System.IO.FileStream -ArgumentList $outFile, ([IO.FileMode]::Create), ([IO.FileAccess]::Write), ([IO.FileShare]::None)
        $GzipStream = New-Object -TypeName System.IO.Compression.GzipStream -ArgumentList $FileStreamIn, ([IO.Compression.CompressionMode]::Decompress)

        # Create  Buffer
        $buffer = New-Object -TypeName byte[] -ArgumentList 1024
        while ($true) {
            $read = $GzipStream.Read($buffer, 0, 1024)
            if ($read -le 0) { break }
            $output.Write($buffer, 0, $read)
        }

        $GzipStream.Close()
        $output.Close()
        $FileStreamIn.Close()
    }
    catch {
        throw $_
        if ($GzipStream) { $GzipStream.Close() }
        if ($output) { $output.Close() }
        if ($FileStreamIn) { $FileStreamIn.Close() }
    }
}