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I know how to swap something with something with privoxy, e.g:

s/class="node ad"/class="node ad" style="display:none"/g

But how can I delete a line with privoxy? E.g.: If a line contains:

RANDOM STRING BEFORE<a href="/forum/100">Offtopic</a></td>RANDOM STRING AFTER

then what should I write in the user.action file to delete the line?

I'm searching for this kind of "sed" effect in Privoxy:

echo -e "asdf\nsomething2\nadf" | sed '/thing2/d;'

If I use "/Offtopic/d" in the user.filter file it doesn't works. (And yes, I have other rules in user.filter perfectly working.)

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You may want to read up on regular expressions. The line you posted is a regular expression:

s/class="node ad"/class="node ad" style="display:none"/g

It means "replace every occurrence of the first string with the second one".

If you want to delete something, you can just leave the second string empty, like so:

s/class="node ad"//g

This would remove all occurrences of that string.

If you want to match a whole line, you could use:


Where ^ is a special character meaning "beginning of line", $ means "end of line", . means any character and * means zero or more repetitions of that character.

So it would match "zero or more repetitions of any character", then "some_string", and then "zero or more repetitions of any character" again (which should achieve what you want).

Here's a good introduction to regular expressions if you want to learn more.

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thanks for trying to help, but "s/^.*some_string.*$//g" doesnt works. it doesn't deletes the line containing the offtopic string. – LanceBaynes Mar 16 '11 at 11:09
That's quite possible, since different programs use different regular expression engines so there are often subtle differences in behaviour. I don't know specifically about Privoxy, so I can't help you there. But you can try replacing the s in the beginning of the expressions with an m. If you really want to understand how this works and how to debug a non-working regular expression, you aren't going to be able to avoid learning the syntax tough. You can start here: regular-expressions.info/anchors.html – Cedric Mar 16 '11 at 12:21

I don't know Privoxy but judging form the replacement statements above this one could work:

s/^.*<a href="/forum/100">Offtopic</a></td>.*$//
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