Providing directly viewable links to specific PDF pages in various TeX manuals

Question

Many questions on the site ask for explanations of specific commands, for TeX/LaTeX/Engine Foo. The informations is often directly available in one of canonical books like "TeX by Topic", "TeX for the Impatient", and of course "The TeXBook". At least some of these are freely and legally available as PDFs (assume for the moment that distribution issues were suitably settled).

It is technically quite simple to drop these PDFs on a website and provide an in-browser viewer for displaying them, also allowing anyone to link directly to a specific page of any hosted book. There may be existing services (Scribd, once upon a time?) to do this, and if not, Setting this up on github pages for example can be done with a couple of hours work. Knowing that the urls will work "forever", participants on the site could provide a directly viewable link to a precise location in a specific resource in comments and answers.

As a concrete example of how this could work, here is a link to the tech demo for the [PDF.js project][1] from Mozilla, an in-browser PDF viewer, displaying a CS paper on javascript engine tech.

Implementation is easy, hosting is not a problem, assuming legal permission is obtainable or available, if there's no actual hinderance to putting this in place, would it be useful or useless? is it a good idea? would it have negative side-effects on answer quality?

Answer 1

As noted in the comments, texdoc already provides this—as long as your browser is configured to view pdf file in the browser because, at least in firefox, appending #page=123 to the texdoc package url is sufficient to have the requested page opened directly. Examples:

• \looseness explanation on Page 288 of TeX By Topic.
• Line breaking parameters in TeX for the impatient.

Edit: texdoc links (it seems) always point to the latest version, so absolute references to page number can break when manuals get revised.

Edit: @thewaywewalk points out that it's possible to link directly to a named destination in the pdf by appending #nameddest=<name> to the url. Google turned up this SO question and this Adobe guide on url parameters for pdf links.

• Section 7.1 of the beamer manual: Link

How are the named destinations created in the first place? hyperref creates them for use with internal hyperlinks (see section 3.2 of the manual), naming each one using its own convention. By using the nameddest url parameter, you can link directly to any locations hyperref creates a named destination for, including section, subsection, figure, table, footnote, etc'.

Edit: Here's a quick python script for listing all named destinations in a given PDF file (pip install PyPDF2):

#!/usr/bin/env python
#
# Invoke from shell as `$ script.py foo.pdf`

import sys
from PyPDF2 import PdfFileReader

pdf = PdfFileReader(open(sys.argv[1], "rb"))
x=pdf.getNamedDestinations()
for n in sorted(x.keys(),key=lambda x:x.rsplit('.',1)[0]):
    print(n)