Localized Live CD/USB hack

#!/bin/bash
# http://askubuntu.com/q/47522/6969
remove_other_lang=true
cd "$(dirname "$(readlink -f "$0")")"
bootcfg=
[ -d isolinux ] && bootcfg=isolinux/isolinux.cfg
[ -d syslinux ] && bootcfg=syslinux/syslinux.cfg
if [ $(id -u) = 0 ]; then
    echo "** WARNING: you're running this script as root **"
    echo "The newly created file localized-init and directory locale-hack will be owned by root"
fi
if [ ! -s "$bootcfg" -o ! -s casper/filesystem.squashfs ]; then
    echo "Please copy this file $0 to the root directory of the Live USB / CD"
    exit 1
fi
read -p "Locale: " lang
if ! apt-cache search 'language-pack-gnome-*' | grep -q "language-pack-gnome-$lang-base"; then
    echo "The language package could not be found"
    exit 1
fi
if [ ! -d locale-hack ]; then
    chmod u+w .
    mkdir locale-hack
    chmod u+w locale-hack
fi
echo "Root permissions are required to mount the squashfs"
mountpoint=$(sudo mktemp -d)
sudo mount -o loop casper/filesystem.squashfs $mountpoint
names=$(grep -E "Filename: pool/main/l/[^/]+/(language-pack-gnome-$lang|language-pack-gnome-${lang}-base|language-pack-$lang|language-pack-${lang})" \
    $mountpoint/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_natty_main_binary-amd64_Packages \
    | cut -d' ' -f2)
sudo umount $mountpoint
sudo rmdir $mountpoint
if [ -n "$names" ]; then
	remove_other_lang && rm -f locale-hack/*.deb
    mirror=archive.ubuntu.com
    host $lang.$mirror >/dev/null && mirror=$lang.$mirror
    for item in $names; do
        wget http://$mirror/ubuntu/$item -O locale-hack/$(basename $item)
    done
	printf "#!/bin/sh\ncp /cdrom/locale-hack/*.deb /var/cache/apt/archives && apt-get -y install language-pack-gnome-%s\nexec init\n" $lang > localized-init
    chmod u+w $bootcfg
    if grep -q 'init=/cdrom/localized-init' $bootcfg; then
        sed "s,locale=\S*,locale=$lang," -i $bootcfg
    else
        sed "s,--,locale=$lang init=/cdrom/localized-init --," -i $bootcfg
    fi
else
    echo "Language packs not found!"
fi