#!/bin/bash
# http://redsymbol.net/articles/unofficial-bash-strict-mode/

set -eu
set -o pipefail

if [ $# -eq 0 ]
then
	echo "usage: tolower filename"
	exit 1
fi

oldname=$1

echo "filename is $oldname"

newname=$(echo $oldname|tr A-Z  a-z)
echo "new filename will be $newname"

if test -e $newname
then
    echo "file $newname already exists"
    exit 1
fi

mv $oldname $newname