sub fix_URL {
    use URI;
    my $in = shift;
    my $url = URI->new($in);
    $url->scheme('http');
    print "input is: $in\n";
    print "fixed url is: $url\n";
}

##</code><code>##

perl> fix_URL 'tp://www.cnn.com'
input is: tp://www.cnn.com
fixed url is: http://www.cnn.com
perl>