PDF Eigenschaften mit PowerShell bearbeiten

<#
.Synopsis
    Get PDF Metadata
.DESCRIPTION
    Get PDF Metadata Properties
.EXAMPLE
    Get-PDFMetaData -FilePath "D:\test.pdf"
.EXAMPLE
    Get-ChildItem -Path "D:\FolderA" -File -Filter *.pdf | Get-PDFMetaData

    You can use the pipeline to get the metadata from your pdf files
.OUTPUTS
   [System.Collections.Generic.Dictionary[string,string]]
#>
function Get-PDFMetaData {
    [cmdletbinding(SupportsShouldProcess=$true)]
    param(
        # FilePath of PDF
        [Parameter(mandatory=$true,ValueFromPipelineByPropertyName=$true)][Alias('Fullname')][string[]]$FilePath
    )
    begin{
        # Funktion zum Laden des iTextSharp Assemblies
        function Load-iTextLibrary {
            if($psscriptroot -ne ''){
                $localpath = join-path $psscriptroot 'itextsharp.dll'
            }else{
                $localpath = join-path $env:TEMP 'itextsharp.dll'
            }
            $zip = $null;$tmp = ''
            try{
                if(!(Test-Path $localpath)){
                    Add-Type -A System.IO.Compression.FileSystem
                    $tmp = "$env:TEMP\$([IO.Path]::GetRandomFileName())"
                    write-host "Downloading and extracting required 'iTextSharp.dll' ... " -F Green -NoNewline

                    (New-Object System.Net.WebClient).DownloadFile('https://www.nuget.org/api/v2/package/iTextSharp/5.5.13.1', $tmp)
                    $zip = [System.IO.Compression.ZipFile]::OpenRead($tmp)
                    $zip.Entries | ?{$_.Fullname -eq 'lib/itextsharp.dll'} | %{
                        [System.IO.Compression.ZipFileExtensions]::ExtractToFile($_,$localpath)
                    }
                    write-host "OK" -F Green 
                }
                if (Get-Item $localpath -Stream zone.identifier -ea SilentlyContinue){
                    Unblock-File -Path $localpath
                }
                Add-Type -Path $localpath
            }catch{
                throw "Error: $($_.Exception.Message)"
            }finally{
                if ($zip){$zip.Dispose()}
                if ($tmp -ne ''){del $tmp -Force -EA SilentlyContinue}
            }
        }
        # iText Library laden
        Load-iTextLibrary
    }
    process{
        foreach($file in $filepath){
            if ($PSCmdlet.ShouldProcess($file,"GetMetadata")){
                # create reader object
                $reader = New-Object iTextSharp.text.pdf.PdfReader $file
                # output metadata
                $reader.Info
                # cleanup
                $reader.Dispose()
            }
        }
    }
}

<#
.Synopsis
    Set PDF Metadata
.DESCRIPTION
    Write Metadata of PDF files
.EXAMPLE
    Set-PDFMetaData -FilePath "D:\test.pdf" -metadata @{'Author'='Mickey Mouse'}

    Set the Author-Field from the pdf to a new value
.EXAMPLE
    Get-ChildItem -Path "D:\FolderA" -File -Filter *.pdf | Set-PDFMetaData -metadata @{'Author'='Mickey Mouse'}

    You can use the pipeline to set the metadata of your pdf files
.OUTPUTS
   [System.Collections.Generic.Dictionary[string,string]]
#>
function Set-PDFMetaData {
    [CmdletBinding(SupportsShouldProcess=$true)]
    param(
        [Parameter(mandatory=$true,ValueFromPipelineByPropertyName=$true)][ValidateNotNullOrEmpty()][Alias('Fullname')][string[]]$FilePath,
        [Parameter(mandatory=$true)][ValidateNotNullOrEmpty()][hashtable]$metadata
    )
    begin{
        # Funktion zum Laden des iTextSharp Assemblies
        function Load-iTextLibrary {
            if($psscriptroot -ne ''){
                $localpath = join-path $psscriptroot 'itextsharp.dll'
            }else{
                $localpath = join-path $env:TEMP 'itextsharp.dll'
            }
            $zip = $null;$tmp = ''
            try{
                if(!(Test-Path $localpath)){
                    Add-Type -A System.IO.Compression.FileSystem
                    $tmp = "$env:TEMP\$([IO.Path]::GetRandomFileName())"
                    write-host "Downloading and extracting required 'iTextSharp.dll' ... " -F Green -NoNewline

                    (New-Object System.Net.WebClient).DownloadFile('https://www.nuget.org/api/v2/package/iTextSharp/5.5.13.1', $tmp)
                    $zip = [System.IO.Compression.ZipFile]::OpenRead($tmp)
                    $zip.Entries | ?{$_.Fullname -eq 'lib/itextsharp.dll'} | %{
                        [System.IO.Compression.ZipFileExtensions]::ExtractToFile($_,$localpath)
                    }
                    write-host "OK" -F Green 
                }
                if (Get-Item $localpath -Stream zone.identifier -ea SilentlyContinue){
                    Unblock-File -Path $localpath
                }
                Add-Type -Path $localpath
            }catch{
                throw "Error: $($_.Exception.Message)"
            }finally{
                if ($zip){$zip.Dispose()}
                if ($tmp -ne ''){del $tmp -Force -EA SilentlyContinue}
            }
        }
        # iText Library laden
        Load-iTextLibrary
    }
    process{
        foreach($file in $filepath){
            if ($PSCmdlet.ShouldProcess($file,"SetMetadata")){
                $reader = $null; $fs = $null;$stamper = $null
                try{
                    # get pdf reader
                    $reader = New-Object iTextSharp.text.pdf.PdfReader $file
                    # create temporary file to store changes into
                    $tmp = join-path ([IO.Path]::GetDirectoryName($file)) ([IO.Path]::GetRandomFileName())
                    # handle case where file with random file already esists, and generate new name until free
                    while(Test-Path $tmp){
                        $tmp = join-path ([IO.Path]::GetDirectoryName($file)) ([IO.Path]::GetRandomFileName())
                    }
                    # create filestream to temp file
                    $fs = [System.IO.FileStream]::new($tmp,[System.IO.FileMode]::Create,[System.IO.FileAccess]::ReadWrite)
                    # create pdf stamper object with file stream as output
                    $stamper = New-Object iTextSharp.text.pdf.PdfStamper $reader,$fs
                    # get metadata
                    $meta = $reader.Info
                    # set metadata from users hashtable
                    $metadata.GetEnumerator() | %{
                        write-verbose "Key '$($_.Key)' set to value '$($_.Value)'."
                        if ($meta.ContainsKey($_.Key)){
                            $meta[$_.Key] = $_.Value
                        }else{
                            $meta.Add($_.Key,$_.Value)
                        }    
                    }
            
                    # set metadata into stamper
                    $stamper.MoreInfo = $meta
                    # close stamper/reader
                    $stamper.Close()
                    $stamper.Dispose()
                    $reader.Close()
                    $reader.Dispose()
                    # remove original file
                    remove-item $file -Force
                    # move modified Version into original location
                    move-item -LiteralPath $tmp -Destination $file -Force
                }catch{
                    write-host $_.Exception.Message -F Red
                }finally{
                    if($reader){$reader.Dispose()}
                    if($fs){$fs.Dispose()}
                    if($stamper){$stamper.Dispose()}
                }
            }
        }
    }
}

# PDF Metadaten auslesen
Get-ChildItem -LiteralPath 'D:\quelle' -File -Filter *.pdf | Get-PDFMetaData
# PDF Metadaten beschreiben
Get-ChildItem -LiteralPath 'D:\quelle' -File -Filter *.pdf | Set-PDFMetaData -metadata @{Author="Max Muster";Title="Another Title"}
# Nur PDFs mit bestimmten Metadata-Werten verändern
Get-ChildItem -LiteralPath 'D:\quelle' -File -Filter *.pdf | ?{(Get-PDFMetadata -FilePath $_.Fullname)['Author'] -eq 'Max Muster'} | Set-PDFMetaData -metadata @{Author="Mickey Mouse";Title="Another Title";Subject="Another Subject";Keywords="Tag1,Tag2"} -Verbose