split-pdf.sh

#!/bin/bash

# split-pdf.sh <INPUT.pdf> <END_PAGE>

if [ -d "${1%.*}" ]; then
    rm -r "${1%.*}"
fi

mkdir "${1%.*}"

__interval_size=20
__range_start=1
__coverpage='true'

if [ "${__coverpage}" == 'true' ]; then
    __range_start="$((__range_start + 1))"
fi

__range_end="${2}"
if [ -z "${__range_end}" ]; then
    __range_end="$(pdftk "${1}" dump_data | grep NumberOfPages | sed -e 's/.* //')"
fi

__stub_size="$(((1 + __range_end - __range_start) % __interval_size))"

__bulk_size="$((1 + __range_end - __range_start - __stub_size))"

(
    if [ "${__coverpage}" == 'true' ]; then
        echo "$((__range_start - 1))-$((__range_start - 1))"
    fi

    seq "${__range_start}" "${__interval_size}" "$((__range_start + __bulk_size - 1))" | while read -r __num; do

        echo "${__num}-$((__num + __interval_size - 1))"

    done

    if ! [ "${__stub_size}" == 0 ]; then
        echo "$((__range_start + __bulk_size))-${__range_end}"
    fi
) | while read -r __range; do
    {
        pdftk "${1}" cat "${__range}" output "${1%.*}/${__range}.pdf"
        echo "${1%.*}/${__range}.pdf"
    } &
done

wait

exit