Modify OpenELEC SYSTEM squashfs filesytem

modify_OpenELEC_squashfs.sh

#!/bin/sh

if [ ! $@ ]; then
  echo "Need OpenELEC archive file. Exiting!"
  exit 0
fi

if [ ! `which mksquashfs` ]; then
  echo "Your system doesn't seem to have squashfs-tools installed"
  echo "You can install this package with:"
  echo "sudo apt-get install squashfs-tools"
  exit 1
fi

FILE=${@%%.tar.bz2}
  
if [ ! -d /tmp/${FILE}_modified ]; then
  echo "=============================================================="
  echo "### extracting SYSTEM & KERNEL file from OpenELEC archive file"
  tar -xjf $@ -C /tmp $FILE/target/SYSTEM
  tar -xjf $@ -C /tmp $FILE/target/KERNEL
  mv /tmp/$FILE/target/KERNEL /tmp/${FILE}_modified.kernel
  echo "    Done!"

  echo "### mount OpenELEC SYSTEM squashfs filesystem"
  sudo mkdir /mnt/$FILE
  sudo mount /tmp/$FILE/target/SYSTEM /mnt/$FILE -t squashfs -o loop
  echo "    Done!"
  echo "### copy squashfs filesystem to tmp folder"
  sudo rsync -a /mnt/$FILE/ /tmp/${FILE}_modified/

  echo "### umount OpenELEC squashfs filesystem and clean tmp files."
  sudo umount /mnt/$FILE
  sudo rmdir /mnt/$FILE
  rm -rf /tmp/$FILE
  echo "    Done!"
else
  echo "!!!"
  echo "/tmp/${FILE}_modified directory exist. Skipping squashfs extract/mount/clone."
  echo "If you want new modify directory please write \"Clean\" and hit Enter for"
  echo "erase /tmp/${FILE}_modified directory then rerun this script!"
  echo "!!!"
fi
echo
echo "You can modify your extracted OpenELEC squashfs filesystem before make new squashfs!"
echo
echo "After you finish, write \"Done\" and press Enter for create new modifed squashfs filesystem!"
echo "Or just write \"exit\" for stop and cancel before creating new squashfs image!"
echo "For cleaning everthing and start over, write \"Clean\" and hit Enter"
echo "!!!NOTE: All command case sensitive and write it without quote(\")!!!" 
while :
do
  read INPUT_STRING
  case $INPUT_STRING in
    Done)
      echo "### creating new OpenELEC squashfs filesystem"
      sudo mksquashfs /tmp/${FILE}_modified /tmp/${FILE}_modified.system -noappend -comp gzip
      sudo chown user:user /tmp/${FILE}_modified.system
      chmod 0644 /tmp/${FILE}_modified.system
      md5sum -t ${FILE}_modified.system > ${FILE}_modified.system.md5
      md5sum -t ${FILE}_modified.kernel > ${FILE}_modified.kernel.md5
      echo "### Finished!"
      echo "new squashfs: /tmp/${FILE}_modified.system"
      echo "=============================================================="
      exit 0
      ;;
    Clean)
      echo "### Cleaning everthing for starting over!"
      sudo rm -rf /tmp/${FILE}_modified*
      echo "### Exiting!"
      echo "=============================================================="
      exit 0
      ;;
    exit)
      echo "### Exiting!"
      echo "=============================================================="
      exit 0
      ;;
    *)
      echo "### Exiting!"
      echo "=============================================================="
      exit 0
      ;;
  esac
done