KOBO Modifies CBR and CBZ files to be displayed correctly on Kobo devices

kobocomic

#!/bin/bash
# kobocomic: Modifies CBR and CBZ files to be displayed correctly on Kobo devices
# Requires perl, rar, unrar, zip, unzip

if [ "$#" -lt 1 ]; then
  echo Supply a CBZ, CBR, ZIP, or RAR file to modify. 
  exit
fi

if [ -d "tmp_kobocomic" ]; then
  echo Directory tmp_kobocomic exists
  exit
fi

for z in "$@"
do
  mkdir tmp_kobocomic
  if [ ${z: -4} == ".cbz" ] || [ ${z: -4} == ".zip" ]; then
    filetype="zip"
  elif [ ${z: -4} == ".cbr" ] || [ ${z: -4} == ".rar" ]; then
    filetype="rar"
  else
    continue
  fi

  if [ $filetype == "rar" ]; then
    echo Unraring: $z
    unrar x "$z" tmp_kobocomic >/dev/null
  else
    echo Unzipping: $z
    unzip -d tmp_kobocomic "$z" >/dev/null
  fi

  cd tmp_kobocomic

  # Add leading zeros to any single or double digits in files, recursively
  # perl is needed for lookahead/behind
  echo \ \ Padding numbers with leading zeros
  find . -depth | while read i; do
    mv -n "$i" "$(dirname "$i")/$(basename "$i" | perl -ne 's/(?<!\d)(\d)(?!\d)/0$1/g; s/(?<!\d)(\d\d)(?!\d)/0$1/g; print;')" 2>/dev/null
  done

  # Append directory name to all files in subdirectories
  echo \ \ Appending directory name to all files
  find . -mindepth 2 -type f | while read i; do
    dir=$(dirname "$i")
    mv "$i" "$dir/$(basename "$dir")_$(basename "$i")"
  done

  if [ $filetype == "rar" ]; then
    echo \ \ Compressing: ${z:0:${#z}-4}_new.cbr
    rar a "${z:0:${#z}-4}_new.cbr" * >/dev/null
    mv "${z:0:${#z}-4}_new.cbr" ..
  else
    echo \ \ Compressing: ${z:0:${#z}-4}_new.cbz
    zip -r "${z:0:${#z}-4}_new.cbz" * >/dev/null
    mv "${z:0:${#z}-4}_new.cbz" ..
  fi

  cd ..
  rm -r tmp_kobocomic  
done