pdf_merge_by_folder_structure.sh

#!/usr/bin/env bash
#
# GPLv3 / Stefan Morgenthaler, 2015;
#
# What?
#
# traverses a given directory down till no subdirectories are present. The pdf
# files within the 'last' directory are merged together and stored in the
# parents folder. The merged document uses the name of the directory, the pdfs
# where located in.
#

echo "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~"
echo "~                  PDF MERGE BY FOLDER STRUCTURE                        ~"
echo "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~"

function main () {
  local dir_now=$1;
  local dir_lst=$(find ${dir_now} ! -path ${dir_now} -type d 2> /dev/null);

  if [ -z "${dir_lst}" ]; then
    pdfmerge ${dir_now}
  else
    for dir in ${dir_lst}; do
      main $dir
    done
  fi
}

function pdfmerge () {
  local path="$1"
  local name="${path}/../$(basename ${path}).pdf";

  [[ -f ${name} || ! -d ${path} ]] && return

  echo "- Processing folder: ${path}"

  gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -sOutputFile=${name} *.pdf \
    && rm -rf ${path};
}

main $1