A Bash Shell Script to find ".aaa" files recursively in a directory, then rename the files as ".bbb".

rename_files.sh

#!/bin/bash

num = 0
for file in $(find ./* -name '*.sgk' | grep -n 'sgk$')
do
  (( num++ ))
  echo "$file"
done
echo -e '\n' "Searched $num files.\n" 

answer="N"
echo -n "Is this result right? Do you want to change the file names? (y/N)"
read answer

if [[ "$answer" == [Yy] ]]
then
  for file in $(find ./* -name '*.sgk' | grep 'sgk$')
  ¦ do
  ¦ ¦ ¦ mv "$file" "${file%.sgk}.php"
  ¦ done
  if [[ $? == "0" ]]; then
  ¦ echo -e "Done.\n"
  fi
else
  echo -e "Okay,bye... \n"
fi