recurse folder find all by optional ext and return only file name

find.sh

#!/bin/bash

if [-z "$1" ]; then
  BASE_PATH=.
else
  BASE_PATH=$1
fi

if [-z "$2" ]; then
  FILTER_EXT=*
else
  FILTER_EXT=$2
fi

find "$BASE_PATH" -type f -iname "$FILTER_EXT" -exec basename {} \;