from_dropbox.sh

#!/bin/sh
#
# Shell script to sync all content of the DropBox
# download folder to the OSX download folder
#
# Best used when attached to a folder action
#

SOURCE="/Users/mrtazz/DropBox/Downloads/"
DESTINATION="/Users/mrtazz/Downloads"

# rsync content from dropbox folder
rsync -r -z --exclude=".DS_Store" $SOURCE $DESTINATION

to_dropbox.sh

#!/bin/sh
#
# Shell script to sync all files smaller than the given size
# from the OSX download folder to the DropBox download folder.
#
# Best used with folder actions.
#

MAXSIZE=20000000 # max 20MB
SOURCE="/Users/mrtazz/Downloads"
DESTINATION="/Users/mrtazz/DropBox/Downloads"
IGNORELIST="/Users/mrtazz/bin/.dropbox_ignore"

# empty ignore list
touch $IGNORELIST
cat /dev/null > $IGNORELIST
echo ".DS_Store" >> $IGNORELIST
echo ".localized" >> $IGNORELIST

# parse files
find $SOURCE -maxdepth 1 | while read f
do
    if [ -d "$f" ]
    then
        basename "$f" >> $IGNORELIST
    else
        filesize=`ls -l "$f" | awk '{print $5}'`
        if [ $filesize -gt $MAXSIZE ]
        then
            basename "$f" >> $IGNORELIST
        fi
    fi
done

# rsync content to dropbox folder
rsync -r -z --exclude-from=$IGNORELIST --delete $SOURCE"/" $DESTINATION