dropbox_backup.sh

size=`rsync --delete --delete-excluded -pthrv --exclude-from \
/Users/paul/.backup/exclude /Users/paul/Documents/ \
/Users/paul/Dropbox | egrep -o "total size is (.*)G" | egrep -o "[0-9\.]+"`
if [ "$size" = "" ]; then
    size=0
fi

if [ `echo "$size < 1.8" | bc` = 0 ]; then
    echo "`date`: WARNING: Size is running out for Dropbox backups.\
    (Currently using ${size} GB.)" 1>&2
elif [ "$1" != "" ]; then
    echo "size: $size GB"
fi