Decrypting PDF files from the command line (Linux/Mac)

Why?

Sometimes you need to mass decrypt PDF files (Telephone bill comes to mind). Opening them one by one and entering the password, finding a way to export them to a non encrypted file all seem too tedious. Let's do it from the command line

Requirements

  • MacOS or Linux or WSL with Linux

How to do it

On Mac

Make sure you have homebrew installed. If not, go HERE

brew install qpdf

On Linux

sudo apt install qpdf

To decrypt a single file

qpdf --password=yourpass --decrypt input.pdf output.pdf

Decrypting everything in a directory

For this, keep all your pdf files that needs to be decrypted into a single directory, and then from that directory, do:

mkdir decrypted

for i in `ls *.pdf`;do qpdf --password=yourpassword --decrypt $i decrypted/$i;done

This will put all the decrypted PDFs in the directory decrypted

Take only one page from the PDF

for i in `ls *.pdf`;do qpdf --password=<pdf password> --decrypt --pages . 1 --  $i decrypted/$i;done