battery_warning

#!/bin/bash
########################################################################
#    Name: battery_warning, Author: Henning Hollermann,                #
#    laclaro@mail.com, http://laclaro.wordpress.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, either version 3    #
#    of the License, or (at your option) any later version             #
#                                                                      #
#    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://gnu.org/licenses/>.  #
#                                                                      #
#    Bash script to be run in background to notify the user(s) on      #
#    critical battery level and to shut down the system if the charge  #
#    level gets too low                                                #
#                                                                      #
#    To send broadcast-messages to all users while running as root     #
#    it uses the notify-send-broadcast script. This is available       #
#    according to the terms of the GPL as well                         #
#                                                                      #
########################################################################

# USER SETTINGS

# sleep time for main loop
SLEEP="60"
# low battery in % (warning begins)
LOW="15"
# critical battery in % (execute action)
CRITICAL="13"
# Seconds to delay shutdown after critical battery level is reached
MAX_DELAY="180"
# on this level ACTION is executed
SUPERCRITICAL="10"
# action performed on SUPERCRITICAL
# Note: executing user has to have permissions to do so
ACTION="sudo /sbin/shutdown now -h"
# notification sound command
PLAY="paplay /usr/share/sounds/freedesktop/stereo/dialog-warning.oga"
# ICONS to display
ICON_supercritical=dialog-warning
ICON_batt_low=battery-caution
ICON_batt_plugged=gnome-power-manager

# SYSTEM SETTINGS

# Battery-Name and AC-Adapter-Name
BAT="BAT0"
AC="AC"
# Files to be found in
AC_ONLINE_FILE="/sys/class/power_supply/$AC/online"
BAT_PRESENT_FILE="/sys/class/power_supply/$BAT/present"
ENERGY_FULL_FILE="/sys/class/power_supply/$BAT/energy_full"
ENERGY_NOW_FILE="/sys/class/power_supply/$BAT/energy_now"
STATE_FILE="/sys/class/power_supply/$BAT/status"
CHARGE_FILE="/sys/class/power_supply/$BAT/energy_now"
# Script to send X-broadcast messages as root
notify_send_broadcast="/usr/local/bin/notify-send-wall"
#notify_send_broadcast="/usr/bin/notify-send"
# file for the process ID
# executing user has to have permissions to write this file
PIDFILE="/var/run/battery_warning/pid"

# END OF SETTINGS
#[ ! -d /var/run/battery_warning/ ] && mkdir /var/run/battery_warning/

start()
{
    echo "Starting battery-warning...";
    if [ ! -e $PIDFILE ]; then
        if [ -w $PIDFILE ]; then
            echo $$ > $PIDFILE
        else
            echo "Warning: cannot create file $PIDFILE."
        fi
    fi

        MAX_BATTERY=$(cat $ENERGY_FULL_FILE)
        LOW_BATTERY=$(($LOW*$MAX_BATTERY/100))
        CRITICAL_BATTERY=$(($CRITICAL*$MAX_BATTERY/100))
        SUPERCRITICAL_BATTERY=$(($SUPERCRITICAL*$MAX_BATTERY/100))
        # Main Loop
        while [ true ]; do

            PRESENT=$(cat $BAT_PRESENT_FILE)
            AC_online=$(cat $AC_ONLINE_FILE)

            if [ "$PRESENT" = "1" ] && [ "$AC_online" = "0" ] ; then

                STATE=$(cat $STATE_FILE)
                CAPACITY=$(cat $ENERGY_NOW_FILE)

                if [ "$CAPACITY" -lt "$CRITICAL_BATTERY" ] && \
                   [ "$STATE" = "Discharging" ];
                then
                    DELAY=0; INTERVAL=10;
                    while [ "$AC_online" = "0" ]; do
                        if [ $CAPACITY -lt $SUPERCRITICAL_BATTERY ] || \
                           [ $DELAY -ge $MAX_DELAY ]; then
                            ${notify_send_broadcast} -u critical \
                                -i $ICON_supercritical \
                                -T 15000 -t 'Achtung' \
                                -m 'Das System wird heruntergefahren!'
                            sleep 3
                            $($ACTION)
                            [ $? -ne 0 ] && ${notify_send_broadcast} -u critical \
                                -i $ICON_supercritical \
                                -m 'DAS SYSTEM KONNTE NICHT HERUNTERGEFAHREN
WERDEN. SCHALTEN SIE DEN COMPUTER SOFORT AUS UM DATENVERLUST ZU VERHINDERN!' \
-T 0 -t 'FEHLER'
                        else
                            ${notify_send_broadcast} -u normal \
                                -i $ICON_batt_low \
                                -m "Sehr niedriger Ladestand
($((100*$CAPACITY/$MAX_BATTERY))%). Das System wird in
$(($MAX_DELAY-$DELAY+$INTERVAL)) Sekunden oder bei einem Ladestand
unter $SUPERCRITICAL% automatisch heruntergefahren." \
                                -T $((1000*$INTERVAL-200)) -t "Achtung"
                        fi
                        sleep $INTERVAL
                        DELAY=$(($DELAY+$INTERVAL))
                        CAPACITY=$(cat $ENERGY_NOW_FILE)
                        AC_online=$(cat $AC_ONLINE_FILE)
                    done
                    ${notify_send_broadcast} -u normal -i $ICON_batt_plugged \
                        -T 10000 \
                        -t "Stromversorgung hergestellt!" \
                        -m "Ladestand: $((100*$CAPACITY/$MAX_BATTERY))%"

                elif [ "$CAPACITY" -lt "$LOW_BATTERY" ] && \
                     [ "$STATE" = "Discharging" ];
                then
                    $($PLAY)
                    ${notify_send_broadcast} -u normal \
                        -T "$(($SLEEP/2*1000))" \
                        -i "$ICON_batt_low" -t "Akku schwach" \
                        -m "$((100*$CAPACITY/$MAX_BATTERY))% verbleibend,
$ACTION bei $SUPERCRITICAL%"
                fi
            fi
            sleep $SLEEP
        done

#    else
#        echo "battery_warning seems to be running..."
#        exit 1;
#    fi;
    return 0;
}


stop()
{
    processID="$(ps -eF|grep -v $$|grep -v 'grep'|grep bash|awk '/battery_warning/ {print $2}')"
    if [ -f $PIDFILE ]; then
        echo "$PIDFILE found. Killing battery_warning..."
        kill `cat $PIDFILE` && rm $PIDFILE
    elif [ -n "$processID" ]; then
        echo "$PIDFILE not found, but battery_warning
running. Killing battery_warning..."
        kill $processID
    else
        echo "Process battery_warning not running.
Nothing to do."
    fi;
    return 0;
}

status()
{
    processID="$(ps -eF|grep -v $$|grep -v 'grep'|grep bash|awk '/battery_warning/ {print $2}')"
    if [ -f $PIDFILE -o "x" != "x$processID" ];
    then
        echo "battery_warning seems to be running with
process ID $processID."
    else
        echo "Process battery_warning not running."
    fi;
    return 0;
}

case $1 in
    start)
        start
        ;;
    stop)
        stop;
        ;;
    restart)
        stop;
        sleep 1;
        start
        ;;
    status)
        status;
        ;;
    *)
        echo "Usage: $0 {start|stop|restart|status}"
        ;;
esac;

exit 0;