osx-duplex-split.sh

#!/bin/bash

function split() {
	file="$1"
	dir="$2"
	odd="$3"
	even="$4"
	pages=$(/usr/local/bin/pdfinfo "$file" | perl -ne 'print "$1" if /^Pages:\s+(\d+)/')

	/usr/local/bin/pdfseparate "$file" "$dir/p-%d.pdf"

	# prepare the list of odd pages in assending
	for o in $(seq 1 2 $pages)
	do
		f="$dir/p-$o.pdf"
		O="$O $f"
	done
	# join the odd pages into one file
	/usr/local/bin/pdfunite $O "$odd"

	if [ $((pages % 2)) == 1 ]
	then	
		# add a blank page to for the "back" of the last page
		f="$dir/p-blank.pdf"
		base64 --decode --output "$f" <<EOH
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
EOH
		E=$f
		pages=$((pages -1))
	fi
	# prepare the list of even pages in descending/reverse order
	for e in $(seq $pages -2 2)
	do
		f="$dir/p-$e.pdf"
		E="$E $f"
	done
	# join the even pages into one file
	/usr/local/bin/pdfunite $E "$even"

	# remove the intermediary files
	rm -f $O $E
}

# remove title and printer settings
shift 2

for f in "$@"
do
	dir=$(mktemp -d "/tmp/duplex-XXXX")
	split "$f" "$dir" "$dir/odd.pdf" "$dir/even.pdf"
	open "$dir/even.pdf"
	open "$dir/odd.pdf"
done

# END