sysfsbatmon

#!/bin/bash

# sysfsbatmon: A simple script to display battery status on screen
#
# Author: Dimitris Lampridis <dlampridis_at_gmail.com>

# (C) Copyright 2010 Dimitris Lampridis
#
# 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://www.gnu.org/licenses/>.

#-------------------------------------------------------------------------
# configuration settings below, adjust as necessary

####################
#  SYSFS SETTINGS  #
####################

# Set this to your power supply's sysfs path 
PSUPATH="/sys/class/power_supply"

# Change this to match the string assigned to your battery
# and ac adapter by sysfs. To find out the available strings, 
# have a look at the SYSFSPATH subfolder names.
BTNAME="BAT1"
ACNAME="ACAD"

####################
#   OSD SETTINGS   #
####################

# Font name and size (default = FreeSerif, size 64)
# Try reducing the size of the OSD is too large for your
# desktop resolution
FONT="FreeSerif"
FONTSIZE="36"

# Character to use for OSD display (default = "|")
OSDCHAR="|"

# Horizontal scaling factor
# Try reducing this if the OSD is so long that it continues
# on a second line (default = 2)
HORIZSCALE="1"

# OSD position, X and Y (default x=10, y=-10)
OSDX="10"
OSDY="-10"

# OSD Fade in/out, in milliseconds (default = 0ms)
FADEIN="0"
FADEOUT="0"

#####################
# PROGRAM LOCATIONS #
#####################

# Adjust the location of required binaries (if needed)
# Should be OK for most Linux distributions
AOSD=/usr/bin/aosd_cat
AWK=/usr/bin/awk
GREP=/bin/grep
ECHO=/bin/echo
CAT=/bin/cat
KILLALL=/usr/bin/killall
TR=/usr/bin/tr
SEQ=/usr/bin/seq
PRINTF=/usr/bin/printf
EXPR=/usr/bin/expr

# end of configuration settings, nothing requires changing below this line
#-------------------------------------------------------------------------

# check that all binaries exist
for i in $AOSD $AWK $GREP $ECHO $CAT $KILLALL $TR $SEQ $PRINTF $EXPR
do
    if [ ! -e $i ]; then
	$ECHO $i" does not exist"
	$ECHO "please install it if missing, and/or adjust the configuration settings to point to the correct location"
	exit
    fi
done

ACPATH=$PSUPATH/$ACNAME
ACSTATPATH=$ACPATH/online

for i in $ACPATH $ACSTATPATH
do
    if [ ! -e $i ]; then
	$ECHO $i" does not exist"
	$ECHO "please adjust script settings"
	exit
    else
	# get AC status
	ACSTATUS=$($CAT $ACSTATPATH)
    fi
done

BTPATH=$PSUPATH/$BTNAME
BTSTATPATH=$BTPATH/present
BTPWRNOWPATH=$BTPATH/energy_now
BTPWRFULPATH=$BTPATH/energy_full

if [ -e $BTPATH ]; then
    for i in $BTSTATPATH $BTPWRFULPATH $BTPWRNOWPATH
    do
	if [ ! -e $i ]; then
	    $ECHO $i" does not exist"
	    $ECHO "please adjust script settings"
	    exit
	fi
    done

    # get battery status
    BTSTATUS=$($CAT $BTSTATPATH)
    BTPWRNOW=$($CAT $BTPWRNOWPATH)
    BTPWRFUL=$($CAT $BTPWRFULPATH)

    # determine battery percentage and adjust text color
    BTPERCENT=$($EXPR \( 100 \* $BTPWRNOW \) \/ $BTPWRFUL)

     if [ $BTPERCENT -ge 50 ]; then
	 GREEN=255
	 RED=$($EXPR \( 5 \* \( 100 - $BTPERCENT \) \) )
     else
	 RED=255
	 GREEN=$($EXPR \( 5 \* $BTPERCENT \) )
     fi

     OSDCOLOR=$($PRINTF "#%.2x%.2x00" $RED $GREEN)

    # determine number of characters to draw on the OSD
    STEPS=$($EXPR $BTPERCENT \/ $HORIZSCALE)

    # "draw" the OSD characters on a temporary string
    OSDI=$BTPERCENT"%"

    if [ $ACSTATUS == "1" ]; then
	OSDI=$OSDI" + "
    else
	OSDI=$OSDI" - "
    fi

    for i in $($SEQ 1 $STEPS)
    do
	OSDI=$OSDI$OSDCHAR
    done
    
else
    OSDCOLOR="green"
    OSDI="on AC, no battery present..."
fi

# kill any existing instances of AOSD_CAT
$KILLALL aosd_cat &> /dev/null

# Print the temporary string on screen with AOSD_CAT
$ECHO "$OSDI" | $AOSD -n "$FONT $FONTSIZE" -R $OSDCOLOR -o $FADEOUT -f $FADEIN -x $OSDX -y $OSDY