#!/bin/bash

# bkup_dpkg.sh
# backup the current list of package for precautionary rollback
# created:  July 3, 2014
# updated:  November 1, 2018 - autocreate dir and provide final message


dirbase="/root/BKUP"

mkdir -p $dirbase

savenum=9

# first delete any tar.gz files older than the last $savenum
# to avoid first-run error on num_files=ls

numbkups=`find $dirbase -type f |wc -l`

if [ $numbkups != "0" ]; then

    num_files=`ls $dirbase |grep tar.gz |wc -l`

    while [ $num_files -gt $savenum ]
        do
        deleteme=` ls -t $dirbase/*.tar.gz |tail -n1`
        # echo "deleteme = $deleteme"
        rm $deleteme
        # reevaluate the number of files remaining
        num_files=`ls $dirbase |grep tar.gz |wc -l`
    done
fi


# datestring=`date +%Y%m%d | tr '\n|\r' ' ' | sed 's/\s$//'`
datestring=$(date +"%Y%m%d")

todaybdir="d_$datestring"

dirfull=$dirbase
dirfull+='/'
dirfull+=$todaybdir
dirfull+='/'

mkdir -p $dirfull


pckg=$dirfull
srcs=$dirfull
rkeys=$dirfull

pckg+="package.list${datestring}"
srcs+="sources.list${datestring}"
rkeys+="repo.keys${datestring}"

dpkg --get-selections | grep -v deinstall > $pckg
cp /etc/apt/sources.list  $srcs
apt-key exportall > $rkeys

tarfile="$todaybdir.tar.gz"
cd $dirbase
tar czf $tarfile  $todaybdir -C $dirbase 2>/dev/null
rm -rf $dirfull

echo "Package backup complete.  See file ${dirbase}/${tarfile}