Renaming multiple files using script in linux/windows

------- in windows

setlocal ENABLEDELAYEDEXPANSION
cd d:
cd D:\kettle_exmples\repot_sample
set count=1
for %%a in (test3*.csv) do (
echo !count!
set /A count=!count!+1
echo "file name %%a  is renaming to sample!count!.csv"
ren "%%a" "sample!count!.csv"
)
endlocal

--------- in linux

echo "begining of script"
cd /home/app/oracle/table_exam/
nooff=`ls -l|wc -l`
echo "there are $nooff files to rename"

j=1
for i in *sample*
do

echo "renaming file $i to sample$j "
mv "$i" sample$j
j=`expr $j + 1`

done