apt_installed.sh

#! /bin/bash
#
# APT Installed
# Compare currently installed packages with archived package list
#
# (c) Winston Astrachan 2019


ARCHIVE_FILE=/etc/apt/basepackages.txt


if [ ! -f "$ARCHIVE_FILE" ]; then
    read -r -p  "Base package list does not exist at $ARCHIVE_FILE. Create it now? [Y/n]" response
    if [[ $response =~ ^(yes|y|Y| ) ]] || [[ -z $response ]]; then
	    dpkg -l | awk 'NR > 3 { print }' | awk '{ print $2 }' | sort > $ARCHIVE_FILE
    else
        echo "Aborting..."
	exit 0
    fi
fi

dpkg -l | awk 'NR > 3 { print }' | awk '{ print $2 }' | sort |  diff -y - $ARCHIVE_FILE | less