How to Join PDF Files into a New One Using pdftk Command on Ubuntu

Installing pdftk on Ubuntu

Install pdftk on Ubuntu.

sudo apt update

sudo apt install pdftk-java

Joining .PDF files

Join .PDF files into a new .PDF file using the following command.

pdftk input1.pdf input2.pdf input3.pdf cat output outfile.pdf

Using a wildcard

You can use a wildcard (*) for input files.

pdftk *.pdf cat output outfile.pdf