CODE EXAMPLE FOR SHELL

rename with zeros padding in loop inside subfolders

for dir in ./*/     # list directories in the form "./dirname/"
do
    dir=${dir%*/}      			# remove the trailing "/"
    cd ${dir}					# go in subfolder	
    zmv '(*).pdf' '${1//(#m)<->/${(l[3][0])MATCH}}.pdf'		# do the renaming
    cd ..						# return to main folder
done