- 

### update action ###

describe_update() {

	echo "Update the kernel symlink to running kernel"

}

describe_update_options() {

	echo "ifunset: Do not override currently set version"

}

do_update() {

	[[ -z $1 || $1 == ifunset ]] || die -q "Usage error"

	[[ $# -gt 1 ]] && die -q "Too many parameters"

	test_for_root

	if [[ -e ${EROOT}/usr/src/linux && ! -L ${EROOT}/usr/src/linux ]]; then

		# we have something strange

		die -q "${EROOT}/usr/src/linux exists but is not a symlink"

	fi

	if [[ $1 == ifunset && -e ${EROOT}/usr/src/linux ]]; then

		# The /usr/src/linux symlink exists, points to a path that

		# exists, and 'ifunset' is provided. Nothing to do.

		return

	fi

	local targets=( $(find_targets) )

	if [[ ${#targets[@]} -eq 0 ]]; then

		die -q "No target kernel-source trees found"

	fi

	local running_kernel_release

	running_kernel_release=$(uname -r)

	if (( $? > 0 )); then

		die -q "Executing uname failed with $?"

	fi

	local running_kernel_symlink_target="linux-${running_kernel_release}"

	if [[ -e ${EROOT}/usr/src/linux ]]; then

		local current_target

		current_target=$(basename "$(canonicalise "${EROOT}/usr/src/linux")")

		if [[ ${current_target} == "${running_kernel_symlink_target}" ]]; then

			# The /usr/src/linux symlink already points to the running

			# kernel's sources. Nothing to do.

			return

		fi

	fi

	local target

	local target_list=()

	for target in "${targets[@]}"; do

		if [[ ${target} == "${running_kernel_symlink_target}" ]]; then

			set_symlink "${target}"

			return

		fi

		target_list+=("\n- ${target}")

	done

	write_error_msg "No kernel sources for running kernel ${running_kernel_release} found."

	if ! is_output_mode brief; then

	   do_list >&2

	fi

	die -q "Could not update the kernel symlink"

}

### helper functions ###

test_for_root() {

	if [[ ! -w ${EROOT}/usr/src ]]; then

		die -q "${EROOT}/usr/src not writeable by current user. Are you root?"

	fi

}