#!/bin/bash read -p "Enter an IP address: " ip_address if [[ $ip_address =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then echo "Valid IP address: $ip_address" else echo "Invalid IP address." fi#!/usr/bin/env bash ip=1.2.3.4 if [[ $ip =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then echo "success" else echo "fail" fi