Update: URI + URI::QueryParam.

#!/usr/bin/env perl
use strictures;
use URI;
use URI::QueryParam;

my $in = URI->new('http://www.bing.com/cr?IG=E1B087FDC4A64C13B6B6F56EE
+3AA3510&CID=04F7052A8A496C5127170CFC8BAE6DD4&rd=1&h=mRcJ09asL7Bb7lrqF
+pfdvPQYVwtg1d5J6vMWCRwXbAk&v=1&r=http%3a%2f%2fwww.raiscuola.rai.it%2f
+articoli%2fstato-della-ricerca-scientifica-in-italia%2f19049%2fdefaul
+t.aspx&p=DevEx,5328.1');

my $out = 'http://www.raiscuola.rai.it/articoli/stato-della-ricerca-sc
+ientifica-in-italia/19049/default.aspx';

my $r = $in->query_param("r");
print $r, $/;

print $out eq $r ? "Same same\n" : "No es correcto\n";

__END__
http://www.raiscuola.rai.it/articoli/stato-della-ricerca-scientifica-i
+n-italia/19049/default.aspx
Same same
[download]