File Attachments

PDF files can have attachments added at the document or page level. The technical foundations of PDF attachments are discussed in Chapter 7. To add an attachment at the file level:

pdftk input.pdf attach_files file1.xls file2.xls output output.pdf

The attachment is added to the end of the list of file-level attachments. To add an attachment at the page level, use the to_page keyword:

pdftk input.pdf attach_files file1.xls to_page 4 output output.pdf

To extract the attachments from a document, writing them to a given directory, we can use the unpack_files keyword:

pdftk input.pdf unpack_files output outputs/

This writes the attachments, under their original filenames, in the outputs directory.