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On creating Org documents using shell scripts

December 28, 2020

I switched recently to Neovim as a full-time text editor. This means that I no longer have access to Emacs Org mode natively. Of course, I still have Emacs on my machine — otherwise, I wouldn’t be able to handle Org file without resorting to Pandoc (which doesn’t handle Babel code chunks, unfortunately). This is just that I want to avoid opening Emacs just to export an Org file to a PDF or HTML document. Hopefully, it’s quite easy to call Emacs from the command line and ask it to compile Org files on the go.

Over the past few months, I wrote some custom templates for PDF and HTML exports, namely the Tufte $\LaTeX$ handout and a hand crafted HTML template that I discussed in previous posts. I know I could write in Markdown and use Pandoc, but I don’t want to forget all those Org files that I wrote in the last two years or so. Moreover, I still believe that the Org specs are better than the Markdown ones, especially because the latter are not really ones.

Here is a simple shell script that takes care of this:

#!/usr/bin/env bash

OPT=$1
FILE=$2

ELISP="/home/chl/Documents/notes/.assets/org-babel.el"
BIB="#+BIBLIOGRAPHY: references ieeetr limit:t option:-nobibsource"

case $OPT in
-pdf)
	emacs --batch -l "$ELISP" --eval "(progn (find-file \"$FILE\") (org-latex-export-to-pdf))"
	;;
-html)
	cp "$FILE" "_$FILE"
	rc="$(grep '#+BIBLIOGRAPHY' "$FILE")"
	[ -z "$rc" ] && echo "$BIB" >>"_$FILE"
	emacs --batch -l "$ELISP" --eval "(progn (find-file \"_$FILE\") (org-html-export-to-html))"
	mv _"${FILE%.org}.html" "${FILE%.org}.html"
	rm "_$FILE"
	;;
*)
	echo "Unknown export format."
	;;
esac

[2022-04-24]
I updated the above script to account for the case where we want to produce both a PDF and an HTML file. The latter requires a #+BIBLIOGRAPHY: directive to generate a proper bibliography with bibtex2html, but this directive is not well handled when exporting to PDF. Maybe there’s an option to detect the exporting backend and discard such a directive in case it is not the HTML format, but I don’t really know. For the time being, I will just add the HTML directive manually. Older version of this script can be found in the Git history.

Basically, it allows to compile an Org file and to produce either a PDF or HTML file, based on the flag passed when invoking the command. Of note, for HTML documents it relies on ox-bibtex, while PDFs are produced using the standard toolchain (biblatex with bibtex backend and pdflatex, but it is not difficult to use biber and lualatex instead). With that in place, I can now regenerate my previous documents without even opening Emacs, which is great after all. I know that the vim-orgmode plugin can take care of this as well, but as you see it is not very difficult to write your own backend for that purpose. I keep my custom settings in the file org-babel.el, which remains available on Github in my “org” repository, in case you’re interested.

emacs unix

See Also

» One Week With Ubuntu » Random thoughts for the end of the year » Welcome Ubuntu » How I stopped worrying about the Mac » Org custom CSS