Weather screensaver background script

[peterson]

As I've put in some work in updating the weather screensaver, I thought I'd share it here. You obviously need the server-side script to create the weather image. Just replace the display-weather.sh script from the original package on the Kindle.

Features:
* customizable interval
* turns WiFi on/off
* refreshes screen

Missing features:
* wake device up when in suspend

Thanks to NiLuJe for the tip about eips.

#!/bin/sh

# how old (in minutes) the screensaver image should be at the least to
# fetch it again from the server
INTERVAL=100

# whether to disable WiFi after the script has finished (if WiFi was off
# when the script started, it will always turn it off)
DISABLE_WIFI=0 

# domain to ping to test network connectivity
TEST_DOMAIN="www.google.com"

# URI of screensaver image
IMAGE_URI="http://www.example.com/weather.png"

# if update failed, the script would try to download the image again
# when it is executed next (depending on the cron job). If you do not
# want this to happen, set DONOTRETRY to 1 and the next update attempt
# will only happen after $INTERVAL minutes
DONOTRETRY=0

# directories
SCREENSAVERFOLDER=/mnt/us/linkss/screensavers/
SCREENSAVERFILE=/mnt/us/linkss/screensavers/bg_medium_ss00.png

# check whether we need to update
if [ -e $SCREENSAVERFILE ]; then
	if test `find $SCREENSAVERFILE -mmin +$INTERVAL`; then
		echo "Screensaver is older than $INTERVAL minutes, going to update."
	else
		echo "Not updating, screensaver is recent enough."
		exit
	fi
else
	echo "Screensaver not found, updating"
fi

# change to directory of this script
cd "$(dirname "$0")"
rm -f .weather-script-output.png

# enable wireless if it is currently off
if test 0 -eq `lipc-get-prop com.lab126.cmd wirelessEnable`; then
	echo "WiFi is off, turning it on now"
	lipc-set-prop com.lab126.cmd wirelessEnable 1
	DISABLE_WIFI=1
fi

# wait for network to be up
TIMER=15
CONNECTED=0
while test 0 -eq $CONNECTED; do
	# test whether we can ping outside
	/bin/ping -c 1 -w 2 $TEST_DOMAIN > /dev/null && CONNECTED=1
	
	# if we can't, checkout timeout or sleep for 1s
	if test 0 -eq $CONNECTED; then
		TIMER=$(($TIMER-1))
		if test 0 -eq $TIMER; then
			echo "No connection after timeout, aborting."
			break
		else
			sleep 1
		fi
	fi
done
	
if test 1 -eq $CONNECTED; then
	if wget -q $IMAGE_URI -O .weather-script-output.png; then
		mntroot rw
		cp .weather-script-output.png $SCREENSAVERFILE
		mntroot ro
		echo "Screen saver image updated"
		
		# refresh screen
		lipc-get-prop com.lab126.powerd status | grep "Screen Saver" && (
			echo "Updating image on screen"
			eips -f -g $SCREENSAVERFILE
		)
	else
		echo "Error updating screensaver"
		if test 1 -eq $DONOTRETRY; then
			touch $SCREENSAVERFILE
		fi
	fi
fi

# disable wireless if necessary
if test 1 -eq $DISABLE_WIFI; then
	echo "Disabling WiFi"
	lipc-set-prop com.lab126.cmd wirelessEnable 0
fi