#!/usr/local/bin/perl
use 5.010;
use strict;
use warnings;
use LWP::UserAgent;

say expand_uri('http://j.mp/dankogai');

sub expand_uri{
  my $uri = shift;
  my $ua  = LWP::UserAgent->new;
  my $res = $ua->head($uri);
  die $res->status_line unless $res->is_success;
  return $res->request->uri;
}