Very simple file backup script using rsync

syncfiles.sh

#!/usr/bin/bash

INTERVAL=10
SRC_DIRS=( Documents )
DEST_HOST=192.168.0.1
DEST_USER=user
DEST_DIR="~/backup" # Quotes are important!

if [ -e ~/.syncfiles.lock ]; then
    echo "lockfile detected"
    exit 0
fi

touch ~/.syncfiles.lock && echo "Created lockfile"

trap "{ rm ~/.syncfiles.lock; echo \"lockfile removed\"; exit 255; }" EXIT

while [ true ]; do
    rsync -r ${SRC_DIRS[@]} $DEST_USER@$DEST_HOST:$DEST_DIR
    sleep $INTERVAL
done