script to get specyfic extension files
myUrl=$1
myExt=$2
#./getExtFromUrl.bash 'http://some.url.com' 'png'
wget \
--recursive \
--level=1 \
--tries=1 \
--no-directories \
--timestamping \
--no-parent \
--accept ".${myExt}" \
--execute robots=off \
--wait=10 \
${myUrl}