Compresses PDFs using a ghostscript batch file, (required since ghostscript doesn't like powershell)

compress_pdfs.ps1

$ArrayList = [System.Collections.ArrayList]@()
Get-ChildItem -Path .\ -Recurse | Where-Object {
	$_ -is [System.IO.FileInfo] `
	-and ($_.Extension.ToLower().CompareTo('.pdf') -eq 0) `
	-and ($_.name.CompareTo('out.pdf') -ne 0)
} | ForEach-Object {
	$ArrayList.add($_.FullName)	
}

workflow Test-Workflow{
	param(
		[Parameter (Mandatory = $true)]
		[System.Collections.ArrayList]$ArrayList
	)
	ForEach -Parallel -throttlelimit 5 ($fileFullName in $ArrayList)
	{
		$GSBATCHPATH=".\gswin64c.bat"
		$file = Get-Item $fileFullName
		$guid = [guid]::NewGuid()
		# Write-Output 'OBJECT: ' $tempFolder
		$tempFolder = Join-Path -Path $file.Directory -ChildPath $guid
		# Write-Output 'tempFolder: ' $tempFolder
		$outputFilePath = Join-Path -Path $tempFolder -ChildPath 'out.pdf'
		# Write-Output 'outputFilePath: ' $outputFilePath
		# Write-Host '$file.FullName: ' $file.FullName
		# Write-Host 'outputFilePath: ' $outputFilePath
		$folder = New-Item $tempFolder -type directory
		$command = '"'+$GSBATCHPATH+'" "'+ $file.FullName+'" "'+$outputFilePath+'"'
		$output = iex "& $command"
		$item = Get-Item $outputFilePath
		if($item.Length -gt 25600){
		  Copy-Item $outputFilePath -Destination $file.FullName
		  Write-Output 'Completed ' $file.FullName
		}else{
		  Write-Output 'WARNING: ' $file.FullName ' did not compress successfully.'
		}
		Remove-Item $tempFolder -Recurse
	}
}
Test-Workflow -ArrayList ($ArrayList)
Write-Host "Press any key to continue ..."

$x = $host.UI.RawUI.ReadKey("NoEcho,IncludeKeyDown")
Write-Host "Finished"

#GSWIN64C.BAT
#set INPUT=%1
#set OUTPUT=%2
#"C:\Program Files (x86)\gs\gs9.21\bin\gswin32c.exe" -q -dNOPAUSE -dBATCH -dSAFER ^
#	-sDEVICE=pdfwrite ^
#	-dCompatibilityLevel=1.3 ^
#	-dPDFSETTINGS=/screen ^
#	-dEmbedAllFonts=true ^
#	-dSubsetFonts=true ^
#	-dColorImageDownsampleType=/Bicubic ^
#	-dColorImageResolution=300 ^
#	-dGrayImageDownsampleType=/Bicubic ^
#	-dGrayImageResolution=300 ^
#	-dMonoImageDownsampleType=/Bicubic ^
#	-dMonoImageResolution=300 ^
#	-sOutputFile=%OUTPUT% %INPUT%