Rename all files in a directory to year_month_day_hour_minutes.ext from date of last modification.

rename.sh

#! /bin/ksh

if [ $# -ne 1 ] ;then
  echo "USAGE: $0 <directoryToScan>"
	exit 1;
fi

for file in "$1"/* ;do
	extension=${file##*.}

	fulldate=`ls -al "$file" | tr -s ' ' | cut -d' ' -f6-7`

	date=${fulldate%% *}
	fulltime=${fulldate##* }

	year=${date:0:4}
	month=${date:5:2}
	day=${date:8:2}

	hour=${fulltime:0:2}
	minutes=${fulltime:3:2}

	echo "mv \""$file"\" \""$year"_"$month"_"$day"_"$hour"_"$minutes"."$extension"\""
done