Stuff
public text v1 · immutablels | grep _[0-9] | grep _[0-9].r > tmp$$
while read file
do
newname=`echo $file | sed 's/\([0-9]\)/0\1/'`
mv $file $newname
done < tmp$$
ls | grep _[0-9] | grep _[0-9].r > tmp$$
while read file
do
newname=`echo $file | sed 's/\([0-9]\)/0\1/'`
mv $file $newname
done < tmp$$