#!/bin/bash

echo "De quina extensio vols sumar les linies?"
read extensio

linies=$(find . -iname "*.$extensio" -exec cat {} \; | wc -l)
#linies=$(find . -iname "*.$extensio" | xargs cat | wc -l)

linies=$(echo "$linies" | tr -s " ")
echo "En total hi ha $linies linies"