If it's only a really short hack, and the page doesn't contain the strings "http://" or "ftp://" outside of anchor tags, that'll be fine. For a slightly more sophisticated method, you can use the old mainstay HTML::TokeParser.

use HTML::TokeParser;

my $count = 0;
my $parsee = HTML::TokeParser->new('test.html')
    or die "couldn't open test.html: $!";
while (my $tag = $parsee->get_tag('a')) {
    $count++ if $tag->[1]{href} =~ m{(http|ftp)://}i;
}
print "There are $count links in this file.\n";
[download]

And if you ever want to do anything more complicated, which you probably will eventually, you have crazyinsomniac's superb tutorial to guide you.