Admin hints
From Lolly's Wiki
Cheat sheets
DNS
Get your IP address
$ dig +short +time=2 +tries=1 myip.opendns.com @resolver1.opendns.com
Remove empty and comment lines
$ grep -Ev "^(\s*|(//|[;#]).*)$" <file>
$ dig +short +time=2 +tries=1 myip.opendns.com @resolver1.opendns.com
$ grep -Ev "^(\s*|(//|[;#]).*)$" <file>