Milter-greylist

On Thu, Dec 21, 2006 at 03:35:25PM -0500, Matt Kettler wrote:
> That said, the the characters matched are really likely to be . or -, so it
> seems inefficient to use back references there anyway.
> 
> Personally I'd use one of these instead:
> 
> /[0-9]{1,3}[-._][0-9]{1,3}[-._][0-9]{1,3}[-._][0-9]{1,3}[-._]/
> 
> /[0-9]+[-._][0-9]+[-._][0-9]+[-._][0-9]+[-._]/
> 
> The primary difference being the first one won't match sequences involving more
> than three numbers at a time, but the second one will.
> (ie: 123-123-123-1234.example.com will not match the first one, but will match
> the second.)

I think the theroy behind the use of backreferences is, the
backrefrence will only pick up the following:

123.132.123.123
123-123-123-123
123_123_123_123

where yours would pickup

123.123-123_123

which, while unlikely to occur, if it did, probably wouldn't be
desired.  Though then again you might want to as well.

-- 
Till Later,
Jake <karrde@...>
http://www.viluppo.net/