#!/bin/bash
#
# Test if the computer is running on line power
# Exit status:
# - 0 (true)  System is on AC power
# - 1 (false) System is not on AC power
#
# NOTE: Batteries are not good indicators unless we also check their type,
#       as some peripherals have batteries.
#
# Copyright 2006 Red Hat, Inc.
# Copyright 2006 Richard Hughes
#
# Based on work from:
#    Richard Hughes <hughsient@gmail.com>
#    Peter Jones <pjones@redhat.com>
#    Stefan Seyfried <seife@suse.de>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of version 2 of the GNU General Public License as
# published by the Free Software Foundation.
#
# 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, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#

# Check for AC/DC/etc adapters
ac_adapters=$(hal-find-by-capability --capability ac_adapter 2>/dev/null)
error=$?

if [ $error -eq 0 ]; then # dbus and HAL are there
	# If there are no AC adapters, it is most likely a desktop.
	# Assume online, since we have no data.
	[ -z "$ac_adapters" ] && exit 0

	# If any of them are online, then we're done.
	for device in $ac_adapters ; do
		present=$(hal-get-property --udi $device --key ac_adapter.present)
		[ "$present" == "true" ] && exit 0
	done
else # fall back to /sys/.../ac/... parsing...
	ADAP=/sys/bus/acpi/drivers/ac/*/power_supply/*/online
	for i in $ADAP; do
		# no adapter -> assume online
		[ $i = "/sys/bus/acpi/drivers/ac/*/power_supply/*/online" ] && exit 0
		read a < $i
		[ $a = 1 ] && exit 0
	done
fi

# If there are adapters, but none are online, we're not on AC.
exit 1
