#! /bin/sh
#
# Set a default boot entry for GRUB, for the next boot only.
# Copyright (C) 2004,2009  Free Software Foundation, Inc.
#
# GRUB is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# GRUB is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with GRUB.  If not, see <http://www.gnu.org/licenses/>.

# Initialize some variables.
prefix=@prefix@
exec_prefix=@exec_prefix@
bindir=@bindir@
sysconfdir="@sysconfdir@"
PACKAGE_NAME=@PACKAGE_NAME@
PACKAGE_VERSION=@PACKAGE_VERSION@
datarootdir="@datarootdir@"
datadir="@datadir@"
if [ "x$pkgdatadir" = x ]; then
    pkgdatadir="${datadir}/@PACKAGE@"
fi

self=`basename $0`

grub_editenv=${bindir}/@grub_editenv@
rootdir=
bootdir=
grubdir=`echo "/@bootdirname@/@grubdirname@" | sed 's,//*,/,g'`

export TEXTDOMAIN=@PACKAGE@
export TEXTDOMAINDIR="@localedir@"

. "${pkgdatadir}/grub-mkconfig_lib"

# Usage: usage
# Print the usage.
usage () {
    gettext_printf "Usage: %s [OPTION] MENU_ENTRY\n" "$self"
    gettext "Set the default boot menu entry for GRUB, for the next boot only."; echo
    gettext_printf "This requires setting GRUB_DEFAULT=saved in %s/default/grub.\n" "$sysconfdir"
    echo
    print_option_help "-h, --help" "$(gettext "print this message and exit")"
    print_option_help "-v, --version" "$(gettext "print the version information and exit")"
    dirmsg="$(gettext_printf "expect GRUB images under the directory DIR/%s instead of the %s directory" "@grubdirname@" "$grubdir")"
    print_option_help "--boot-directory=$(gettext "DIR")" "$dirmsg"
    echo
    gettext "MENU_ENTRY is a number, a menu item title or a menu item identifier."; echo
    echo
    gettext "Report bugs to <bug-grub@gnu.org>."; echo
}

argument () {
  opt=$1
  shift

  if test $# -eq 0; then
      gettext_printf "%s: option requires an argument -- \`%s'\n" "$0" "$opt" 1>&2
      exit 1
  fi
  echo $1
}

# Check the arguments.
while test $# -gt 0
do
    option=$1
    shift

    case "$option" in
    -h | --help)
	usage
	exit 0 ;;
    -v | --version)
	echo "$self (${PACKAGE_NAME}) ${PACKAGE_VERSION}"
	exit 0 ;;

# Accept for compatibility
    --root-directory)
	rootdir=`argument $option "$@"`; shift ;;
    --root-directory=*)
	rootdir=`echo "$option" | sed 's/--root-directory=//'` ;;

    --boot-directory)
    bootdir=`argument $option "$@"`; shift;;
    --boot-directory=*)
    bootdir=`echo "$option" | sed 's/--boot-directory=//'` ;;

    -*)
	gettext_printf "Unrecognized option \`%s'\n" "$option" 1>&2
	usage
	exit 1
	;;
    *)
	if test "x$entry" != x; then
	    gettext "More than one menu entry?" 1>&2
	    echo >&2
	    usage
	    exit 1
	fi
	entry="${option}" ;;
    esac
done

if test "x$entry" = x; then
    gettext "Menu entry not specified." 1>&2
    echo >&2
    usage
    exit 1
fi

if [ -z "$bootdir" ]; then
    # Default bootdir if bootdir not initialized.
    bootdir=/@bootdirname@

    if [ -n "$rootdir" ] ; then
        # Initialize bootdir if rootdir was initialized.
        bootdir=${rootdir}/@bootdirname@
    fi
fi

grubdir=`echo "${bootdir}/@grubdirname@" | sed 's,//*,/,g'`

prev_saved_entry=`$grub_editenv ${grubdir}/grubenv list | sed -n 's/^saved_entry=//p'`
if [ "$prev_saved_entry" ]; then
    $grub_editenv ${grubdir}/grubenv set prev_saved_entry="$prev_saved_entry"
else
    # We need some non-empty value for prev_saved_entry so that GRUB will
    # recognise that grub-reboot has been used and restore the previous
    # saved entry. "0" is the same as an empty value, i.e. the first menu
    # entry.
    $grub_editenv ${grubdir}/grubenv set prev_saved_entry=0
fi
$grub_editenv ${grubdir}/grubenv set saved_entry="$entry"

# Bye.
exit 0