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I am doing literate programming in Emacs org mode. When I do the Latex export to a pdf, I would like the name of the file the code gets tangled to to be displayed by each code block. I can't find a suitable header argument in the manual.

Here is my org file:

A piece of Python code:
#+BEGIN_SRC python :tangle pythontest.py
  print("hello")
#+END_SRC

Here is my .emacs:

(org-babel-do-load-languages
 'org-babel-load-languages
 '((python . t)))

Here is a screenshot of the part of the pdf export with text on it: Latex pdf output

8n8
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1 Answers1

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There are a couple of options that all require some hacking on your part. These two examples show how to use filters to modify export of src blocks.

http://kitchingroup.cheme.cmu.edu/blog/2014/09/22/Showing-what-data-went-into-a-code-block-on-export/

http://kitchingroup.cheme.cmu.edu/blog/2013/09/30/Attaching-code-blocks-to-a-pdf-file-during-export/

They are a little clunky to me. An alternative approach is to use a preprocessing hook like this where you modify a temporary copy of the org-file prior to export:

(defun add-tangled-name (backend)
  (let ((src-blocks (org-element-map (org-element-parse-buffer) 'src-block #'identity)))
(setq src-blocks (nreverse src-blocks))
    (loop for src in src-blocks
      do
      (goto-char (org-element-property :begin src)) 
      (let ((tangled-name (cdr (assoc :tangle (nth 2 (org-babel-get-src-block-info))))))        
        (insert (format "=Tangle: %s=\n" tangled-name))))))

(let ((org-export-before-processing-hook '(add-tangled-name))
      (org-latex-pdf-process '("pdflatex -shell-escape -interaction nonstopmode -output-directory %o %f"
                   "pdflatex -shell-escape -interaction nonstopmode -output-directory %o %f"
                   "pdflatex -shell-escape -interaction nonstopmode -output-directory %o %f"))
      (async nil)
      (subtreep t)
      (visible-only nil)
      (body-only nil)
      (ext-plist '()))
  (org-open-file (org-latex-export-to-pdf nil t)))

This is what I would probably do these days.

John Kitchin
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  • Thank you very much, that is a good idea about using a preprocessing hook. The code in your post doesn't work for me when I paste it into my .emacs, but maybe I'm doing the wrong thing with it? I don't know enough elisp to understand it all. – 8n8 Aug 15 '16 at 19:03
  • what does "doesn't work" mean? Do you get an error? It probably shouldn't go in .emacs. I would put it in an elisp src block in the document you want to export, and run it from there. You can put it in a section tagged :noexport: so that block won't show in your document. – John Kitchin Aug 16 '16 at 11:42