dedup_run.sh

#!/bin/bash

tmp1=`tempfile`
tmp2=`tempfile`
dir=`pwd`

if [ "$1" != "--run-here" ]; then
        echo "$0 --run-here"
        exit 1
fi

cd /opt/dedup
find -type f | grep -vE '^\./(DEBIAN|dedup)' | xargs -d '\n' sha256sum > $tmp1

cd "$dir"
find -type f | grep -vE '^\./(DEBIAN|dedup)' | xargs -d '\n' sha256sum > $tmp2

cat >dedup_install.sh <<'EOF'
#!/bin/bash

dedup()
{
        local file_source="$1"
        local file_target="$2"
        local uid="$3"
        local gid="$4"
        local mode="$5"
        local mtime="$6"

        cp "$file_source" "$file_target"
        chown $uid:$gid "$file_target"
        chmod $mode "$file_target"
        touch -d @$mtime "$file_target"
}

cd /

echo -n "dedup: installing files... "
EOF

cat >dedup_remove.sh <<'EOF'
#!/bin/bash

echo -n "dedup: removing files... "
EOF

cat $tmp2 | while read line; do
        checksum=${line:0:64}
        filename=${line:68}

        if [ -L "${dir}/${filename}" ]; then
                continue
        fi

        line2=`cat $tmp1 | grep -E "^${checksum} " | head -n 1`

        if [ "$line2" == "" ]; then
                continue
        fi

        filename2=${line2:68}

        uid=`stat --format '%u' "${dir}/${filename}"`
        gid=`stat --format '%g' "${dir}/${filename}"`
        mode=`stat --format '%a' "${dir}/${filename}"`
        mtime=`stat --format '%Y' "${dir}/${filename}"`

        echo "dedup '/opt/dedup/${filename2}' '${filename}' $uid $gid $mode $mtime" >> dedup_install.sh
        echo "rm '${filename}'" >> dedup_remove.sh

        rm "${dir}/${filename}"
done

echo "echo \"done.\"" >> dedup_install.sh
echo "echo \"done.\"" >> dedup_remove.sh

chmod 700 dedup_remove.sh
chmod 700 dedup_install.sh

rm $tmp1
rm $tmp2