renaming_files_from_csv.sh

#!/bin/bash
# this is run within the directory from which the script is executed and relies upon the csv file titled 'index.csv'

# note in the oldname to newname process, bash on mac introduces /r (carriage return) chacters within the csv, 
# therefore a step variable is added that overcomes the rename issue
     while read line          
     do          
          oldName=${line%,*}
          step=${line#*,}
          newName=${step%$'\r'}
          mv "$oldName" "$newName"
     done <"index.csv"

This provides an example of the index template used within the renaming bash gist.