#!/usr/bin/perl -Tw

use URI::Find;
use strict;

my $text = " ... long string with lots of URLs ... ";

my @urls;
find_uris($text, sub {
    my ($uri, $orig_uri) = @_;
    push @urls, $orig_uri;
});

print join("\n", @urls), "\n";
exit 0;
[download]

Note that the CPAN documentation for URI::Find is out-of-date with the newest version (0.04) exporting only the one function, find_uris, which takes two arguments, the string to be searched and a function reference.

perl -e 's&&rob@cowsnet.com.au&&&split/[@.]/&&s&.com.&_&&&print'

use strict;
use feature ':5.10';
use LWP::UserAgent;

our $ua = LWP::UserAgent->new;
$ua->max_redirect(10);
my $uri = 'https://t.co/O4qjsxuCsV';

say expand($uri);

sub expand {
    my ($short) = @_;
    my $long;
     my $response = $ua->get($short);
    if ($response->is_success) {
            my @redirects = $response->redirects();
            if (@redirects) {
                $long = $redirects[$#redirects]->header('location');
            }
            elsif ($response->header('refresh')) {
                $long = $response->header('refresh');
                $long =~ s/0\;URL\=//;
            }
            return $long;
    }
    else {
        return $short;
    }    
}
[download]

I suspect you intended to reply to Unshortening t.co links.

"Should work for any shortened URL"

The first search result I could find for 'url shorten', which didn't require payment or signing up was https://shorturldotat, which does not work with this code, however the following does work:

#!/usr/bin/perl
use strict;
use warnings;
use LWP::UserAgent;
use feature 'say';
use Data::Dumper;
my $url = 'https://shorturl[dot]at/REDACTED';
my $uaname = 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (
+ KHTML, like Gecko) Chrome/40.0.2214.93 Safari/537.36';

my $ua = LWP::UserAgent->new;
$ua->agent( $uaname );
my $resp = $ua->get($url);
my $final = $resp->request()->uri();
while ($resp) {
   say $resp->request()->uri();
   $resp = $resp->previous();
}

say "Final URL: $final";
[download]

In short I don't think you're going to find a one size fits all solution, without automating a browser like WWW::Mechanize::Chrome.

Update: url cloaked a little, it's a bit spammy.

Here is what I finally came up with

According to the thread dates, it only took you 21 years!!!

Hopefully, marto is right about you being in the wrong thread rather than in a time warp...

--
perl -pe "s/\b;([st])/'\1/mg"