if test -z "$DIST_FORMAT" ; then
	DIST_FORMAT="gztar"
fi

if test -z "$DIST_FILE" ; then
	echo "Environment variable DIST_FILE must not be empty" >&2
	exit 1
fi

if test -n "$INSTALL_DIR" ; then
	mkdir -p "$INSTALL_DIR"
	tar_opts="--strip-components=1 -C \"$INSTALL_DIR\""
fi

case "$DIST_FORMAT" in
gztar)
	tar -xzf "$DIST_FILE" $tar_opts
	;;
*)
	echo "Unsupported DIST_FORMAT ($DIST_FORMAT)" >&2
	exit 1
	;;
esac