#!/bin/bash

awk -F "." '{if(NF!=4){print "error"}
            else if((0<=$1 && $1<256) && (0<=$2 && $2<256)  &&(0<=$3 && $3<256)  && (0<=$4 && $4<256) )
            {print "yes"}
            else
            {print "no"}

}'