apk-backup-restore.sh

#!/bin/bash

ADB=${ADB:-adb}
DEST=${DEST:-apks}

if [ $# -lt 1 ]; then
	echo "ERROR: Specify operation (backup/restore)."
	exit 1
fi

if [ "$1" = backup ]; then
	rm -rf "$DEST"
	mkdir -p "$DEST"
	cd "$DEST"

	OLDIFS="$IFS"
	IFS=$': =\r'
	while read -r -u 3 _1 package _2 installer; do
		user=0
		system=0
		echo "Backing up '$package'..."
		mkdir -p "$package"
		while read -r -u 4 _3 path; do
			case "$path" in
			/data/*)
				((user++))
				[ "$system" -gt 0 ] && break # happens?
				$ADB pull "$path" "$package"
				;;
			*)
				((system++))
				;;
			esac
		done 4< <($ADB shell pm path "$package")
		if [ "$system" -gt 0 ] || [ "$user" -eq 0 ]; then # happens (user)?
			rm -rf "$package"
		else
			echo "$package $installer" >> packages.dat
		fi
	done 3< <($ADB shell pm list packages -i -u)
	IFS="$OLDIFS"

	exit 0
fi

if [ "$1" = restore ]; then
	if ! [ -d "$DEST" ]; then
		echo "ERROR: Directory '$DEST' does not exist."
		exit 3
	fi
	cd "$DEST"
	if ! [ -f packages.dat ]; then
		echo "ERROR: File 'packages.dat' does not exist."
		exit 4
	fi

	while read -r -u 3 package installer; do
		opts="-i $installer"
		echo "Restoring '$package'..."
		[ "$installer" = null ] && opts=""
		pushd "$package" > /dev/null
		$ADB install-multiple -r "$opts" ./*.apk
		popd > /dev/null
	done 3< packages.dat

	exit 0
fi

echo "ERROR: Unsupported operation specified."
exit 2