Bash - Scripting - Converting file name to web ready file name

#!/bin/bash
#
# web_ready.sh
#
if [ "${1}" ]
then
extension=$( echo "${1}" | awk -F . '{print $NF}' )
mv "${1}" $( echo "${1}" | iconv -f utf-8 -t ascii//translit | tr -d '[:punct:]' | tr [:upper:] [:lower:] | sed "s/${extension}$/.$extension/" | tr ' ' '-')

# echo $(echo "${1}" | tr [:upper:] [:lower:])
# echo "$extension"

else
        echo "Enter file"
fi

Results:

#web_ready.sh "What They Know, What You Don't.pdf"

#ls -ltr

# what-they-know-what-you-dont.pdf