Simple PDF Reader

readpdf.ps1

# https://www.nuget.org/packages/itextsharp/ (5.5.13.3)
# https://github.com/itext/itextsharp/releases/tag/5.5.13
Add-Type -Path "$psscriptroot\itextsharp.dll" # 5.5.13 and lower have no dependencies

function Read-Pdf {
	[CmdLetBinding(DefaultParameterSetName="Path")]
	param (
		[Parameter(ParameterSetName="Path", Mandatory, ValueFromPipeline, ValueFromPipelineByPropertyName, Position=0)]
		[alias('fullname')][string[]]$path,
		[Parameter(ParameterSetName="Instance", Position=0)]
		[iTextSharp.text.pdf.pdfreader]$instance,
		[int[]]$page, # page selector by number
		[switch]$raw, # return content as a single string
		[alias('filter')][string[]]$pattern, # content filter; the value is treated as a regular expression
		[switch]$passThru, # return PDF object
		[switch]$enumerate # separate output by file/instance
	)
	end {
		$paths = if ($input) {$input} elseif ($path) {$path} elseif ($instance) {$instance}
		foreach ($file in $paths) {
			$pdf = if ($instance) {$instance}
			else {
				if ($file.gettype().name -eq 'DirectoryInfo') {continue}
				if ($file.gettype().name -eq 'FileInfo') {$file = $file.fullname}
				$file = (Resolve-Path $file -ErrorAction 0).ProviderPath
				if ($file -and (Test-Path $file)) {
					#[iTextSharp.text.pdf.pdfreader]::new($file)
					[iTextSharp.text.pdf.pdfreader]::new([iTextSharp.text.pdf.RandomAccessFileOrArray]::new($file,$true),$null)
				} else {
					Write-Warning "File '$file' not found."
					continue
				}
			}
			if ($passThru) {$pdf; continue}
			$range = 1..$pdf.NumberOfPages
			if ($page) {$range = ($page.where{$_ -in $range})}
			$text = foreach ($p in $range) {
				if ($pattern) {
					[string[]]([iTextSharp.text.pdf.parser.PdfTextExtractor]::GetTextFromPage($pdf,$p).Split([char]0x000A) | Select-String -pattern $pattern)
				} else {
					[iTextSharp.text.pdf.parser.PdfTextExtractor]::GetTextFromPage($pdf,$p).Split([char]0x000A)
				}
			}
			if ($enumerate) {
				[pscustomobject]@{
					File    = if ($instance) {''} else {$file}
					Content = if ($raw) {$text | Out-String} else {$text}
				}
			} elseif ($raw) {$text | Out-String} else {$text}
			if (-not $instance) {$pdf.Close(); $pdf.Dispose()}
		}
	}
} # END Read-Pdf