Question

I’m detecting @replies in a Twitter stream with the following PHP code using regexes. In the first pattern, I replace @replies at the beginning of the string; in the second, I replace the @replies which follow a space.

$text = preg_replace('!^@([A-Za-z0-9_]+)!', '<a href="http://twitter.com/$1" target="_blank">@$1</a>', $text); $text = preg_replace('! @([A-Za-z0-9_]+)!', ' <a href="http://twitter.com/$1" target="_blank">@$1</a>', $text); 

How can I best combine these two rules without false flagging [e-mail] as a reply?

Answer 1

OK, on a second thought, not flagging whatever@email means that the previous element has to be a ‘non-word’ item, because any other element that could be contained in a word could be signaled as an email, so it would lead:

!(^|\W)@([A-Za-z0-9_]+)! 

but then you have to use $2 instead of $1.