#!/bin/sh

usage () {
	cat <<EOF>&2
Usage: ${0##*/} FILES

Rename FILES to lowercase if destination does not exist.

EOF
}

[ $# -eq 0 ] && usage && exit 1
[ "$1" = "-h" ] && usage && exit
[ "$1" = "--" ] && shift

for f ; do
	filename=${f##*/}

	case "$f" in
	*/*) dirname="${f%/*}" ;;
	*) dirname="." ;;
	esac

	nf="$(echo "$filename" | awk '{print tolower($0)}')"
	[ "$nf" = "$filename" ] && continue
	newname="${dirname}/${nf}"
	mv -nv "$f" "$newname"
done