Convert images to one combined PDF file (based on pdftk and imagemagic)

pdfer.sh

#!/usr/bin/env bash

set -e

if [[ ! "$1" ]]; then
	echo "Usage: pdfer page1.png page2.png..."
	exit 1
fi

output_file="combined.pdf"
pages=""

for file in ${@}; do
	if [[ ! "$file" =~ .pdf$ ]]; then
		convert "${file}" "${file}.pdf"
		pages+=" ${file}.pdf"
  else
    pages+=" ${file}"
	fi
done

pdftk ${pages} cat output ${output_file}

rm -f ${pages}

echo "Done - saved as $output_file"