newsbin.com

Quade can you add in the regex feature to "exclude" results? I think it's the ^operator, so you return all search results that DON'T include the ^[text] string. That would eliminate junk posts that litter results containing that string. I don't want to create a filter for it as it is usually a one-off situation.
Thanks

As far as I know there is no regex operator to exclude (the ^ operator means anchor to start) which I have always though was a shame. I am sure Quade is just using a standard RegEx engine - not something custom written for Newsbin.

There is NO exclude for regex

You're right, I must have misunderstood regex examples on the web. Too bad, I'd still love to see an "exclude string" capability to eliminate garbage postings.

Add you word to exclude into the exclude filter !

As I said in my first post, I don't want a permanent filter for occasional garbage posts.

Why not use lookahead?
negative lookahead:
(?!foo) means not followed by "foo".
^(?!.*foo) means start of line not followed by any number of chars and then "foo"
positive lookahead:
(?=bar) means followed by "bar"
^(?=.*bar) means start of line followed by any number of chars and then "bar" .

Lookahead is a regex "zero width operator", which means (among other things) that you can stack 'em, so...

^(?!.*foo)(?=.*bar)
Will pick up any lines that have "bar" but not "foo".

bobkoure wrote:Why not use lookahead?
negative lookahead:
(?!foo) means not followed by "foo".
^(?!.*foo) means start of line not followed by any number of chars and then "foo"
positive lookahead:
(?=bar) means followed by "bar"
^(?=.*bar) means start of line followed by any number of chars and then "bar" .

Lookahead is a regex "zero width operator", which means (among other things) that you can stack 'em, so...

^(?!.*foo)(?=.*bar)
Will pick up any lines that have "bar" but not "foo".

I was looking for the same thing, with a twist:

I would like to exclude all posts with "foo" except those with "newfoo"?
(The simple negative lookahead above, (?!foo), also excludes "newfoo")

You could try '\b', which is another "zero width" operator - means "word boundary"
\bfoo\b matches foo 1foo 1234foo33 but not newfoo

So... ^(?!.*\bfoo\b) is all posts not including the word foo.

bobkoure wrote:You could try '\b', which is another "zero width" operator - means "word boundary"
\bfoo\b matches foo 1foo 1234foo33 but not newfoo

So... ^(?!.*\bfoo\b) is all posts not including the word foo.

Great. Thanks!!