arxiv -> a5paper

#!/usr/bin/env bash

# Download an arXiv article source and recompile the latex as an a5 for
# reading on a smaller device such as an e-reader or tablet

# download the source in a temporary folder
wd="$(pwd)"
tmpdir="/tmp/arxiv-a5/$1"
mkdir -p "$tmpdir"
cd "$tmpdir"
url=https://arxiv.org/e-print/"$1"
wget -q -O "$1".tar.gz --user-agent arxiv-a5 "$url"
tar zxf "$1".tar.gz

# guess the main tex file
texfile=$(grep -l '\\begin{document}' *.tex)

# exit if main tex file not found
[ -z "$texfile" ] && echo "arXiv paper or main tex file not found in $tmpdir" && exit 1

# remove existing geometry options, if any
sed -i '/^\\usepackage.*{geometry}/d' "$texfile"
# insert the a5 paper size override
sed -i '/^\\begin{document}/i \\\usepackage[a5paper, margin=1cm]{geometry}\n' "$texfile"

# compile (twice to get references)
pdflatex --halt-on-error -draftmode -interaction batchmode "$texfile" > "$1".pdflatex.log
pdflatex --halt-on-error -interaction batchmode "$texfile" >> "$1".pdflatex.log || echo "Could not compile latex"

# move the result and tidy up
mv "$(basename $texfile .tex)".pdf "$wd"/"$1".pdf
cd "$wd"