#!/bin/sh
FN=julenisse-gespenst-$(date +%Y-%m-%d-%H-%M)

cd /

time /usr/local/bin/tarsnap \
    -c \
    --keyfile /root/tarsnap.key \
    --cachedir /var/lib/tarsnap/cache \
    -f $FN \
    --one-file-system \
    --exclude core.\* \
    --exclude tmp \
    --exclude var/lib/tarsnap/cache \
    .

backups=$(/usr/local/bin/tarsnap \
                   --keyfile /root/tarsnap.key \
                   --cachedir /var/lib/tarsnap/cache \
                   --list-archives)

[ 10 -lt $(echo $backups | wc -w) ] && exit 0

for a in $( echo $backups | fmt -1 | sort -r | sed -n '5~3p' ); do
    time /usr/local/bin/tarsnap \
        -d \
        --keyfile /root/tarsnap.key \
        --cachedir /var/lib/tarsnap/cache \
        -f $a
done