for i in *.jpg; do mv "$i" "`basename $i .jpg`.JPG"; done

ls foo*.jpg | awk '{print("mv "$1" "$1)}' | sed 's/foo/bar/2' | /bin/sh

find . -name "foo*.jpg" | awk '{print("mv "$1" "$1)}' | sed 's/foo/bar/2' | /bin/sh