Order your photos from your usb card to your hard drive, ordered by years/month, no risk of override or accidental deletion with md5sum

gistfile1.txt

#!/bin/bash
# Author : Nicolas Coevoet
# This script read exifs informations of files and copy them to output/YEAR/MONTH/yearmonthday_hourminutesecond.ext
# It checks md5sum in case file with the same name is found and skip it md5sum matchs or create a new one with _<digit> if different.
# Dependencies are exiftool exiv2

if [ ! -n "${1}" ]; then
	echo "Usage : ./{0} src/ output/"
	exit 1
fi
if [ ! -n "${2}" ]; then
	echo "Usage : ./{0} ${1}/ output/"
	exit 1
fi
if [ ! "${3}" = "run" ]; then
	echo "${0} run"
	find "${1}" -type f -exec "${0}" {} "${2}" "run" \;
	echo "Done."
else
	#echo "${1}"
	extension=${1##*.}
	extension=$(echo "${extension}" | tr 'A-Z' 'a-z')
	time=`exiftool -DateTimeOriginal -fast -s -s -s -q "${1}" 2>/dev/null`
	nb=$((`echo $time | sed 's/[^:]//g' | wc -m`-1))
	if [ ! $nb -ne 0 ]; then
		echo "	${1} Ignored - no exif data"
	else
		full=`echo ${time} | cut -d' ' -f1`
		year=`echo ${full} | cut -d':' -f1`
		month=`echo ${full} | cut -d':' -f2`
		day=`echo ${full} | cut -d':' -f3`
		local=`echo ${time} | cut -d' ' -f2`
		hour=`echo ${local} | cut -d':' -f1`
		min=`echo ${local} | cut -d':' -f2`
		second=`echo ${local} | cut -d':' -f3`
		dir="${2}${year}/${month}/" #here you can specify ${year}/${month}/${day}/ if you want
		mkdir -p "${dir}"
		copied=0
		count=0
		filename="${year}${month}${day}_${hour}${min}${second}"
		file="${dir}${filename}"
		skipped=0
		if [ -s "${dir}${filename}.${extension}" ]; then
			sumSrc=`md5sum "${1}" | cut -d' ' -f1`
			sumOut=`md5sum "${dir}${filename}.${extension}" | cut -d' ' -f1`
			if [ "${sumSrc}" = "${sumOut}" ]; then
				echo "${1} Skipped"
				skipped=1
			else
				while [ $copied -eq 0 ];do
					if [ -s "${dir}${filename}_${count}.${extension}" ]; then
						sumOut=`md5sum "${dir}${filename}_${count}.${extension}" | cut -d' ' -f1`
						if [ "${sumSrc}" = "${sumOut}" ]; then
							echo "${1} Skipped"
							copied=1
							skipped=1
						else
							count=$(expr $count + 1)
						fi
					else
						cp -a "${1}" "${dir}${filename}_${count}.${extension}"
						file="${dir}${filename}_${count}"
						echo "${1} --> ${dir}${filename}_${count}.${extension}"
						copied=1
					fi
				done
			fi
		else
			cp -a "${1}" "${dir}${filename}.${extension}"
			echo "${1} --> ${dir}${filename}.${extension}"
		fi
	fi
fi