Automatically download NASA Astronomy Pictures of the Day

apod.sh

# Download the latest pic of the day from NASA and delete or archive any
# previous ones in a specified directory. Optionally create a copy of the most
# current picture to allow OSX to pick up pictures as wallpapers
#
# Steve Challis 2011
# http://schallis.com/2011/mar/20/nasa-astronomy-picture-of-the-day-background/

# Get a fresch picture from NASA
todays_pic=`ruby -rubygems latest_nasa_photo.rb`

if [ -d tmp ]; then
  rm -rf tmp
fi
mkdir tmp
cd tmp
curl -O --silent $todays_pic
file=`ls -1 *.jpg`
mv $file ..
cd ..
rm -rf tmp
echo "Setting wallpaper to $file"
osascript -e 'tell application "Finder"' \
  -e "set desktop picture to POSIX file \"`pwd`/$file\"" \
  -e "end tell"

gistfile1.sh

# Run at 12 o'clock every day
0   0   *   *   *   ~/Pictures/Wallpapers/apod/apod.sh

latest_nasa_photo.rb

require 'httparty'
require 'json'
require 'awesome_print'

latest_image = HTTParty.get('http://api.flickr.com/services/feeds/photos_public.gne?id=35067687@N04&lang=en-us&format=rss_200').parsed_response.first[1]['channel']['item'].first['content']['url']

puts latest_image