::= | " " ::= | "." ::= [ [ ] ] ::= | ::= | "-" ::= | ::= any one of the 52 alphabetic characters A through Z in upper case and a through z in lower case ::= any one of the ten digits 0 through 9 #### use Net::DNS::DomainName; my $host = "foo.example.com"; my $bare = (Net::DNS::DomainName->new($host)->label)[0]; print "$bare\n"; # prints "foo"