You have another problem besides returning on the first try. In your code if https://securesite.com is a good refererer then http://securesite.com is also good. Unless that is what you wanted, but you didn't state that.

try using grep and lc and test for equality

#!/usr/local/bin/perl -w
use strict;

my @referers = qw| https://www.imdb.com http://www.yoda-speak.org |;

$ENV{HTTP_REFERER} = 'http://www.yoda-speak.org';
print  check_url($ENV{HTTP_REFERER},@referers) , "\n";

$ENV{HTTP_REFERER} = 'https://www.imdb.com';
print  check_url($ENV{HTTP_REFERER},@referers) , "\n";

$ENV{HTTP_REFERER} = 'http://badsite.net';
print  check_url($ENV{HTTP_REFERER},@referers) , "\n";


sub check_url {
    my $http_referer = shift;
    my @referers = @_;
    return scalar(grep ( lc($http_referer) eq lc($_) , @referers ));
}
[download]

grep

Mynd you, mønk bites Kan be pretti nasti...