#!/bin/bash

IFS=$'\n'
if [ -z "$1" ]
then echo rename files in current folder replacing arg1 with arg2.
     echo '-n for match non ascii, replace with arg2'
     exit
fi
c=0
if [ "$1" = "-n" ]
then for file in $( ls | grep -P "[\x80-\xFF]" )
   do echo "$file" '->' "$( echo $file | tr -d \\n\\r | tr -c [:print:] '\000' | sed s/'\x0'/"$2"/g )"
      c=$(( $c + 1 ))
   done
   echo $c' matches. Sure?'
   read i
   for file in $( ls | grep -P "[\x80-\xFF]" )
   do mv -iv -- "$file" "$( echo $file | tr -d \\n\\r | tr -c [:print:] '\000' | sed s/'\x0'/"$2"/g )"
   done
  exit
fi
for file in $( ls | grep -- "$1" )
do echo "$file" '->' "$( echo $file | sed s/"$1"/"$2"/g )"
   c=$(( $c + 1 ))
done
echo $c' matches. Sure?'
read i
for file in $( ls | grep -- "$1" )
do mv -iv -- "$file" "$( echo $file | sed s/"$1"/"$2"/g )"
done