Merge pdf files and automatically create a table of contents with each file as an entry

Question

I have several pdf files (chapter1.pdf, chapter2.pdf, etc.), each one being a chapter of a book. I now how to merge them into a single pdf (I use the command pdfunite from poppler), but since the output file is big, it's difficult to find a chapter without having them indexed in a table of contents. So how to create an embedded table of contents in which each merged chapter is an entry?

Note that I do not want to create a page in the output file which contains the list of chapters and their respective page numbers. I want the index/table of contents metadata of an pdf file, that can be browseable in any pdf reader's (or ebook device's) which supports such feature.

You can use pdftk as you can read [here](https://unix.stackexchange.com/questions/17065/add-and-edit-bookmarks-to-pdf). — Hölderlin, May 31 '17 at 23:54

Mateen Ulhaq · Answer 1 · 2021-03-16T09:18:36.530

Non-destructive version of @bu5hman's answer:

#!/bin/bash

out_file="combined.pdf"
bookmarks_file="/tmp/bookmarks.txt"
bookmarks_fmt="BookmarkBegin
BookmarkTitle: %s
BookmarkLevel: 1
BookmarkPageNumber: %d
"

rm -f "$bookmarks_file" "$out_file"

declare -a files=(*.pdf)
page_counter=1

# Generate bookmarks file.
for f in "${files[@]}"; do
    title="${f%.*}"
    printf "$bookmarks_fmt" "$title" "$page_counter" >> "$bookmarks_file"
    num_pages="$(pdftk "$f" dump_data | grep NumberOfPages | awk '{print $2}')"
    page_counter=$((page_counter + num_pages))
done

# Combine PDFs and embed the generated bookmarks file.
pdftk "${files[@]}" cat output - | \
    pdftk - update_info "$bookmarks_file" output "$out_file"

It works by:

Generating bookmarks.txt.
Merging PDFs into combined.pdf.
Updating combined.pdf with bookmarks.txt.

How would one go about doing this recursively through several folders, and building the bookmarks from folder structure, i.e. sections/subsections depending on folder depth? — Cpt Reynolds, Dec 27 '22 at 17:47
@CptReynolds For that, I would probably just write the "Generate bookmarks file" section in Python. — Mateen Ulhaq, Jan 02 '23 at 22:41

score 5 · Answer 2 · edited Nov 19 '19 at 08:01

A function I use all the time to do exactly this. Just make sure the pdfs sort properly in sequence in the expansion.

tp="/tmp/tmp.pdf"
td="/tmp/data"
for i in *.pdf; do
    echo "Bookmarking $i"
    printf "BookmarkBegin\nBookmarkTitle: %s\nBookmarkLevel: 1\nBookmarkPageNumber: 1\n" "${i%.*}"> "$td"
    pdftk "$i" update_info "$td" output "$tp"
    mv "$tp" "$i"
done
pdftk *.pdf cat output myBook.pdf

Merge pdf files and automatically create a table of contents with each file as an entry

2 Answers2