#!/bin/bash

read -ep 'please enter a filename: ' filename

if [ -f "$filename" ]; then
  echo 'This is a regular file.'
else
  echo 'This is not a regular file.'
fi

if [ -O "$filename" ]; then
  echo 'This file is owned by the effective user ID.'
else
  echo 'This file is not owned by the effective user ID.'
fi

if [ -w "$filename" ]; then
  echo 'This file is writable.'
else
  echo 'This file is made writable for all users now.'
  chmod o+w "$1"
fi