There’s an easy way to add attachments to an existing pdf-file. Just install the pdftk-package of your favourite linux-distribution und use it like followed:
pdftk input.pdf attach_files file1.tex file2.tex output new_doc.pdf
This command will use the existing
input.pdf and attaches the existing files
file2.tex. A new file called
new_doc.pdf will be created which contains those 2 attachments.
You can attach any file you want! I use it to include the Latex-sources to the my pdf’s but there are many other reason’s to add attachments.