Powershell: Compress and decompress byte array

psCompress.ps1

# Compress and decompress byte array
  
function Get-CompressedByteArray {

	[CmdletBinding()]
    Param (
	[Parameter(Mandatory,ValueFromPipeline,ValueFromPipelineByPropertyName)]
        [byte[]] $byteArray = $(Throw("-byteArray is required"))
    )
	Process {
        Write-Verbose "Get-CompressedByteArray"
       	[System.IO.MemoryStream] $output = New-Object System.IO.MemoryStream
        $gzipStream = New-Object System.IO.Compression.GzipStream $output, ([IO.Compression.CompressionMode]::Compress)
      	$gzipStream.Write( $byteArray, 0, $byteArray.Length )
        $gzipStream.Close()
        $output.Close()
        $tmp = $output.ToArray()
        Write-Output $tmp
    }
}


function Get-DecompressedByteArray {

	[CmdletBinding()]
    Param (
		[Parameter(Mandatory,ValueFromPipeline,ValueFromPipelineByPropertyName)]
        [byte[]] $byteArray = $(Throw("-byteArray is required"))
    )
	Process {
	    Write-Verbose "Get-DecompressedByteArray"
        $input = New-Object System.IO.MemoryStream( , $byteArray )
	    $output = New-Object System.IO.MemoryStream
        $gzipStream = New-Object System.IO.Compression.GzipStream $input, ([IO.Compression.CompressionMode]::Decompress)
	    $gzipStream.CopyTo( $output )
        $gzipStream.Close()
		$input.Close()
		[byte[]] $byteOutArray = $output.ToArray()
        Write-Output $byteOutArray
    }
}

[string] $text = "some text to encode"
Write-Host "Text: " ( $text | Out-String )

[System.Text.Encoding] $enc = [System.Text.Encoding]::UTF8
[byte[]] $encText = $enc.GetBytes( $text )

$compressedByteArray = Get-CompressedByteArray -byteArray $encText
Write-Host "Encoded: " ( $enc.GetString( $compressedByteArray ) | Out-String )

$decompressedByteArray = Get-DecompressedByteArray -byteArray $compressedByteArray
Write-Host "Decoded: " ( $enc.GetString( $decompressedByteArray ) | Out-String )

• my issue is if the input is a compressed folder the output is a decompressed somthing, trying to wrap my head around this one

$file = [System.IO.File]::ReadAllBytes("C:\temp\webcontrol\wc.gz.zip")

$im = New-Object System.IO.MemoryStream(,$file)

$gzipStream = New-Object System.IO.Compression.GzipStream $im, ([IO.Compression.CompressionMode]::Decompress)

$output = New-Object System.IO.MemoryStream

$gzipStream.CopyTo($output)

$gzipStream.Close()

$im.Close()

$filebytes = $output.ToArray() 

• here is my issue, my output is undefined

[io.file]::WriteAllBytes("C:\temp\webcontrol\wco",$filebytes)

Running this today I get:

New-Object : Cannot find an overload for "GZipStream" and the argument count: "2".
At line:11 char:23
+ ... zipStream = New-Object System.IO.Compression.GzipStream $output, ([IO ...
+                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [New-Object], MethodException
    + FullyQualifiedErrorId : ConstructorInvokedThrowException,Microsoft.PowerShell.Commands.NewObjectCommand

Though I actually see two overloads in the docs. How to fix this?

• this removed the overload for me

$file = [System.IO.File]::ReadAllBytes("C:\temp\webcontrol\wc.gz.zip")

$im = New-Object System.IO.MemoryStream(,$file)

Running this today I get:

New-Object : Cannot find an overload for "GZipStream" and the argument count: "2".
At line:11 char:23
+ ... zipStream = New-Object System.IO.Compression.GzipStream $output, ([IO ...
+                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [New-Object], MethodException
    + FullyQualifiedErrorId : ConstructorInvokedThrowException,Microsoft.PowerShell.Commands.NewObjectCommand

Though I actually see two overloads in the docs. How to fix this?

The $input variable is special and can cause weird behavior if you try to use it like a normal variable. This particular error is being caused because the $input variable is of type ArrayListEnumeratorSimple, but the method expects a MemoryStream variable. Just find an replace all instances of $input with another variable name, like $inStream.