#!/bin/sh -e
#
# Copyright (C) 2014 Michael Gilbert <mgilbert@debian.org>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

cmd=$(cat /etc/default/init)
test ! -x $cmd && \
	echo "error: $cmd either does not exist or is not executable" && \
	exit 1 || true

grub=/etc/default/grub
test -z $cmd && init="" || init=" init=$cmd"
cat $grub | while read line; do
	if echo $line | grep GRUB_CMDLINE_LINUX_DEFAULT >/dev/null; then
		arguments=$(echo $line | cut -d\" -f2 | sed 's/init=[^ ]*//' | sed 's/^[\t ]*//' | sed 's/[\t ]*$//' | tr -s ' ')
		echo GRUB_CMDLINE_LINUX_DEFAULT=\"$arguments$init\" >> $grub.new
	else
		echo $line >> $grub.new
	fi  
done
mv $grub.new $grub
update-grub
