use strict;
use warnings;

my @b = ( "corp.home.ge.com",
          "scotland.gcf.home.ge.com",
          "marketing.ge.com",
          "home-school.com" );
my %b; $b{$_} = 0 for @b;

for (<DATA>) {
    $_ = lc $_;
    m/^https?:\/\/(?:www.)?(.*?)[\/\n]/;
    $b{$1}++ if exists $b{$1};
}

print "$_ => $b{$_}\n" for @b;

__DATA__
http://corp.home.ge.com/page/whatever.php3
https://scotland.gcf.home.ge.com
http://sub.marketing.ge.com/
HTTP://marketing.ge.com/
http://www.home-school.com/mypage.html
http://home-school.com/mypage.html
https://MARKETING.ge.com/testpage.html