Usando CURL
curl -s checkip.dyndns.org|sed -e 's/.*Current IP Address: //' -e 's/<.*$//' curl -s http://whatismyip.org/
Usando wget
wget -q -O - checkip.dyndns.org|sed -e 's/.*Current IP Address: //' -e 's/<.*$//'
Usando Lynx
lynx -dump checkip.dyndns.org lynx -dump www.whatismyip.com | grep 'Your IP'