Sometimes it is necessary to check, remove or modify the metadata of PDF files. Here is a quick post to show how it can be done in the terminal on Ubuntu Checking PDF metadata Most PDF viewers have an option for showing the metadata of PDF files. This can also be done in the terminal using the “pdfinfo” command-line tool. First, we need to install the “poppler-utils” package: sudo apt install poppler-utils Once installed, you can check the metadata by using the following command: