#!/usr/bin/env bash
if (( $# < 2 )); then
echo "USAGE: $0 DIGITS FILES"
return 1
fi
digits="$1"
shift 1
i=1
for file in $@; do
mv -n "$file" "$(dirname $file)/$(printf %0${digits}d $i).${file##*.}"
i="$((i+1))"
done