Unfully support for Regular Expression

CrendKing · Post by **CrendKing** » Sun Aug 12, 2007 4:54 pm

I want to block "abc/def.com", block "xyz/def.com" but not "img/def.com", i.e. I want to block any address when "img" is not preceding "/def.com".

I found this regular expression /(?<!img\/)def\.com/ could work. However, it is an invalid expression in Adblock Plus 0.7.5.1. Does Adblock Plus not fully support regular expression? Or there is any alternative expression could work? Thanks!

Alan · Post by **Alan** » Sun Aug 12, 2007 6:08 pm

The Adblock Plus documentation page at http://adblockplus.org/en/filters#regexps points to "check out documentation on regular expressions to learn how to write them" at http://developer.mozilla.org/en/docs/Co ... cts:RegExp

Does that help?

CrendKing · Post by **CrendKing** » Sun Aug 12, 2007 6:18 pm

Yes, I checked that document and found no rule about ?<!. However I think I may write an equivalent like /img(?!\/def\.com)/ , since Firefox support (?!expr) expression, right?

Alan · Post by **Alan** » Sun Aug 12, 2007 6:24 pm

CrendKing wrote:right?

I don't know. I'm not an expert. Put together something that does what you want and report back what it is. The experts might have alternatives.

chewey · Post by **chewey** » Sun Aug 12, 2007 6:38 pm

(?<!) is a "negative lookbehind" used in PCRE (i.e. Perl). Gecko's JS engine doesn't
support this operator, and since ABP relies on Gecko's JS capabilities, it doesn't either.

Yes, Gecko's JS supports (?!), but this won't help in this case.
The easiest way I see is to make it two rules:

Code: Select all

/def.com
@@img/def.com