#!/bin/bash

list()
{
	dpkg --get-selections | grep -P "\t+hold$"
}

hold()
{
	check_exist $1
	if [ $? -eq 1 ]; then
		echo -e "ERROR:\tThe package '$1' not found!"
		return
	fi

	check_hold $1
	if [ $? -eq 0 ]; then
		echo -e "INFO:\tThe package '$1' is already hold."
		return
	fi

	check_install $1
	if [ $? -eq 1 ]; then
		echo -e "WARN:\tThe status of package '$1' is NOT 'install'."
		return
	fi

	echo -e "$1 hold" | dpkg --set-selections

	check_hold $1
	if [ $? = 1 ]; then
		echo -e "ERROR:\tHold package '$1' fault!"
	else
		echo -e "INFO:\t`dpkg --get-selections | grep -P "^$1\t+"`"
	fi  
}

unhold()
{
	check_exist $1
	if [ $? -eq 1 ]; then
		echo -e "ERROR:\tThe package '$1' not found!"
		return
	fi

	check_install $1
	if [ $? -eq 0 ]; then
		echo -e "INFO:\tThe package '$1' is already unhold."
		return
	fi
	
	check_hold $1
	if [ $? -eq 1 ]; then
		echo -e "WARN:\tThe status of package '$1' is NOT 'hold'."
		return
	fi

	echo -e "$1 install" | dpkg --set-selections

	check_install $1
	if [ $? = 1 ]; then
		echo -e "ERROR:\tUnHold package '$1' fault!"
	else
		echo -e "INFO:\t`dpkg --get-selections | grep -P "^$1\t+"`"
	fi
}

check_exist()
{
	PKG=`dpkg --get-selections | grep -P "^$1\t+"`
	if [ -z "$PKG" ]; then
		return 1
	else
		return 0
	fi
}

check_install()
{
	PKG=`dpkg --get-selections | grep -P "^$1\t+install$"`
	if [ -z "$PKG" ]; then
		return 1
	else
		return 0
	fi  
}

check_hold()
{
	PKG=`dpkg --get-selections | grep -P "^$1\t+hold$"`
	if [ -z "$PKG" ]; then
		return 1
	else
		return 0
	fi
}

list_not_install()
{
	dpkg --get-selections | grep -v -P "\t+install$"
}

get_help()
{
	echo -e "Usage: $0\t\t\tList holded packages."
	echo -e "       $0 pkg1 [pkg2 ...]\thold packages."
	echo -e "       $0 -u pkg1 [pkg2 ...]\tunhold packages."
	echo -e "       $0 -v\t\t\tList packages not 'install'."
	echo -e "       $0 -h/-?\t\t\tThis help text."
}

case $1 in
'')
	list
	;;
-v)
	shift
	if [ -z "$1" ]; then
		list_not_install
	else
		get_help
	fi
	;;
-u)
	shift
	if [ -z "$1" ]; then
		echo -e "WARN:\tMissing package name after -u option."
	else
		while [ -n "$1" ]; do
			unhold "$1"
			shift
		done
	fi
	;;
-*)
        get_help
        ;;
-)
	get_help
	;;
*)
	while [ -n "$1" ]; do
		hold "$1"
		shift
	done
	;;
esac