$ wget -q -O - checkip.dyndns.org|sed -e 's/.*Current IP Address: //' -e 's/<.*$//'
202.130.101.34
$ curl -q -s http://checkip.dyndns.org | egrep -o '[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+'
202.130.101.34
$ curl -q -s http://checkip.dyndns.org | egrep -o '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}'
202.130.101.34