apt-user-installed

#!/bin/bash

if test "x$1" = "x--install"
then
	if test \! -f "/etc/sysgit/apt-packages"
	then
		echo "Info: No apt-package file found. Thanks."
		exit 0
	fi
	apt install -y $(cat /etc/sysgit/apt-packages)
	exit 0
fi

get_packages() {
	manual="$(apt-mark showmanual | sort)"

	# substract:
	substract="$(dpkg-query -W -f='${Package};${Priority}\n' | grep -E ";(required|important)$" | sed -r 's/;.*$//' | sort -u)"

	manual="$(comm -2 -3 <(echo "${manual}") <(echo "${substract}"))"

	#echo "${manual}" | xargs apt-cache rdepends --installed --no-recommends --no-suggests --no-conflicts --no-breaks --no-replaces --no-enhances

	depends="$(grep -E "^(Pre-)?Depends:" /var/lib/dpkg/status)"

	for p in ${manual}
	do
		# check if no rdepends:
	#	if test "x$(apt-cache rdepends --installed --no-recommends --no-suggests --no-conflicts --no-breaks --no-replaces --no-enhances "${p}" | grep -vE "^    " | wc -l)" = "x2"
		if test "x$(echo "${depends}" | grep -E " ${p} | ${p}, | ${p}:| ${p}\$")" = "x"
		then
			echo ${p}
		fi
	done
}

if test "x$1" = "x--save"
then
	if test \! -f "/etc/sysgit/apt-packages" || test \
			"/var/lib/dpkg/status" -nt "/etc/sysgit/apt-packages"
	then
		mkdir -p "/etc/sysgit"
		get_packages >/etc/sysgit/apt-packages
	fi
else
	get_packages
fi