On 18.01.2011 22:02, Ronald J Kimball wrote: > On Tue, Jan 18, 2011 at 01:29:50PM -0600, Christopher Stone wrote: >> Hey Folks, >> >> I've been looking at positive and negative assertions until my head is >> spinning. :) >> >> What I want to do is find the entirety of line 1 but *not* line 2: >> >> ./Address Book.app >> ./Address Book.app/Contents/CodeResources.app >> >> So I want to find a line that ends with ".app" but it cannot contain ".app" >> except at the end. >> > > Here's the approach I usually take for this kind of task: > > ^(?>(?:(?!\.app).)*)\.app$ > > (?:(?!\.app).)* matches a substring that doesn't contain ".app". It does > this by checking whether the next part of the string is ".app"; if it's > not, it matches one character, and repeats. > > (?>...) prevents the regex from backtracking into its subexpression once it > matches. We know that if the regex doesn't get to the end of the string, > backtracking isn't going to help. > > > But I also thought of a simpler approach in this case: > > ^(?!.*\.app.*\.app).*\.app$ > > That one uses a negative lookahead to make sure the string doesn't contain > .app twice, and then matches if it contains .app at the end of the string. > > Ronald >
Hello all! Did I oversaw something? This looks little bit like an overkill. Would it not be sufficient, to search for an and of line with grep: \./Address Book\.app$ Or if it is not at the end of line, probable with a word boundary: \./Address Book\.app\b Best greetings from Munich marek -- You received this message because you are subscribed to the "BBEdit Talk" discussion group on Google Groups. To post to this group, send email to bbedit@googlegroups.com To unsubscribe from this group, send email to bbedit+unsubscr...@googlegroups.com For more options, visit this group at <http://groups.google.com/group/bbedit?hl=en> If you have a feature request or would like to report a problem, please email "supp...@barebones.com" rather than posting to the group. Follow @bbedit on Twitter: <http://www.twitter.com/bbedit>
