I’ve been trying to tackle a very tricky issue recently. I have a folder of PDF files sitting in a folder, and on a regular basis, the files in that folder need to be password protected and then moved elsewhere.
Acrobat Pro has a great feature called Actions, where you can set a workflow for documents. Normally, I would pick the folder containing these files and use a saved workflow to encrypt each file with a pre-determined password.
Unfortunately, the contents of some of these files (fillable forms) prevent that workflow from applying properly, meaning some files can’t be password protected in this manner. Since they need to be encrypted, it was important to find another way to do this.
I discovered that if I used a PDF printer to print the file to PDF again, the resulting file could be encrypted without issue. This was a good start, but not of much use if I needed to open each file and print the file manually. I needed something that could be automated. Specifically, I needed to be able to:
- Automatically select the correct printer;
- Specify a folder and work through each PDF in that folder;
- Print each PDF to a file without any interaction during the process (so the output path must also be automatic);
- Avoid interfering with the default print device beyond this task.
So, I turned to PowerShell and Adobe’s PDF printer (which comes with Adobe Acrobat’s licensed products).
Adobe’s PDF printer is useful because it’s possible to specify a default output directory in the printer preferences, and thus avoid a pop-up appearing for each PDF prompting for a save location. Free PDF printers like CutePDF don’t have this option (although I believe they are available in their paid-for products).
After that, everything can be done in PowerShell. Here’s the code I wrote:
$defaultprinter = Get-WmiObject -Query "SELECT * FROM win32_Printer WHERE default=$true"
$PDFprinter = Get-WmiObject -Query "Select * From Win32_Printer Where Name = 'Adobe PDF'"
$PDFprinter.SetDefaultPrinter()
Dir C:\test\*.pdf | Foreach-Object { Start-Process -FilePath $_.FullName -Verb Print }
$defaultprinter.SetDefaultPrinter()
The first line retrieves the current default printer. This is so that, at the end of the task, the default printer is restored (it will be changed for the duration of this task).
The second line retrieves the Adobe PDF printer. On my computer, it’s called “Adobe PDF”. If the named printer doesn’t exist, the script will return a horrible looking error and fail (I’ve no real need for error handling in this script).
The third line of this script sets the Adobe PDF printer from the second line as the default printer.
The fourth line of the script takes a specified directory and, for each PDF in that directory, prints the document. As the default printer is the Adobe PDF printer, that’s the printer that is used. In the Adobe PDF printer, I’ve already set a couple of options:
- Disabled the option to show the PDF as it’s created (I want the task to run in the background as far as possible);
- Specified an output directory where the PDFs will be saved to;
- Set the PDF quality settings (in this case, “Standard”, for compatibility).
The final line restores the default printer, as it’s not likely I would want the Adobe PDF printer set as the default printer.
For me, that’s not the end of the process as I then need to go back in to Acrobat and encrypt the files, but the PowerShell script makes this a much quicker process than it would otherwise be.
I’d love to be able to encrypt the files from the same script, but unfortunately I’ve not found a way to do that. Nevertheless, a time-consuming problem made easier.