Find total size of files of an extension given as input in bash

 #!/bin/bash
echo "Please enter extension"
read ext
total=0
for i in $(pwd)/*.$ext

do

#filesize=$((`stat --printf="%s" $i`))
#filesize=$((`wc -c $i | awk '{print $1}'))
filesize=$((`wc -c $i | cut -d " " -f 1`))
total=$(($total+$filesize))
done

echo "The total size of $ext files in present directory is $total"

#alternate way

#!/usr/bin/bash
read -rep $'Please enter the extension\n' ext
total=0
for i in `ls`
do
if [[ "$i" == *"$ext"* ]]
then
#echo $i
total=$(($total + `du -k $i | cut -f 1`))
fi
done
echo "The total size of $ext files is $total"