Tryag File Manager

//usr/lib/ubuntu-release-upgrader/release-upgrade-motd

#!/bin/sh -e
#
#    91-release-upgrade - display upgrade message or update the cache
#                         in the background
#
#    Copyright (C) 2010 Canonical Ltd.
#
#    Authors: Dustin Kirkland <kirkland@canonical.com>
#
#    This program 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, version 3 of the License.
#
#    This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.

stamp=/var/lib/ubuntu-release-upgrader/release-upgrade-available
if [ -f "$stamp" ]; then
	# Stamp exists, see if it's expired
	now=$(date +%s)
        lastrun=$(stat -c %Y "$stamp") 2>/dev/null || lastrun=0
        expiration=$(expr $lastrun + 86400)
        if [ $now -ge $expiration ]; then
		# Older than 1 day old, so update in the background
		/usr/lib/ubuntu-release-upgrader/check-new-release -q > "$stamp" &
	elif [ -s "$stamp" ]; then
		# Less than 1 day old, and non-empty, so display now
		cat "$stamp"
		echo
	fi
elif [ "$(id -u)" = 0 ]; then
	# No cache at all, so update in the background
	/usr/lib/ubuntu-release-upgrader/check-new-release -q > "$stamp" &
fi