From: Bill Kelly <billk@...>
Date: 2004-11-11T10:12:14+09:00
Subject: Re: A Wiki/Spam Report

From: "Jim Weirich" <jim@weirichhouse.org>
>
> (3) Detecting the addition of links is difficult because the change is
> submitted to the wiki as a whole page, with nothing to distinguish the new
> material from the old.  To determine that we would have to run a diff
> algorithm between the old and new content.

How about:

... er... my Perl is very rusty... I concur with the <shudder>... :)

..uh..um...

my $old = "abc http://blah.com def ftp://foo.bar ghi";

my $new = "abc http://spam1.com def ftp://foo.bar ghi http://spam2.com";

my %old_links;
$old_links{$&}++ while $old =~ m{\w+://[^\s)>]+}g;

my $new_links;
while($new =~ m{\w+://[^\s)>]+}g) {
  $new_links++ unless defined $old_links{$&};
}

print "new links: $new_links\n";


...The above doesn't count negatively when links disappear,
only positively when new links appear...  I'd first written
this version:

my %delta;
$delta{$&} -= 1 while $old =~ m{\w+://[^\s)>]+}g;
$delta{$&} += 1 while $new =~ m{\w+://[^\s)>]+}g;

my $d;
foreach my $val (values %delta) {
  $d += $val;
}

print "delta links: $d\n";


...But I'd guess the former is probably more like what
we'd want to count.


HTH,

Regards,

Bill