Rename to checksum

find -maxdepth 1 -type f -exec sh -c 'mv -v "$0" `md5sum "$0" | cut -d\  -f1``echo "$0" | grep -o "\.[^\./]*$"`' {} ';' &&
for s in `seq 31 -1 1`; do for i in * ; do f=`echo $i | cut -c 1-$s``echo $i | grep -o "\.[^\./]*$"`; [ -f $f ] || mv -v $i $f; done; done