#!/bin/bash for addr in $(cat $1) do x=$(expr substr $addr 1 8) y=$(expr substr $addr 9 8) z=$(expr substr $addr 17 8) t=$(expr substr $addr 25 8) addr_dot=$((2#$x)).$((2#$y)).$((2#$z)).$((2#$t)) echo $addr_dot done>$2 exit