# Str.scan **URL:** \ **Category:** Ruby\ **Created:** [June 15, 2007, 8:02am UTC](https://www.ruby-forum.com/t/str-scan/106907 "2007-06-15T08:02:37Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![banry](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/898d66/32.png) [@banry](https://www.ruby-forum.com/u/banry)\ **Post date:** [June 15, 2007, 8:02am UTC](https://www.ruby-forum.com/t/str-scan/106907/1 "2007-06-15T08:02:37Z")
I have a page of html, the usual thing. It has an ordered list. So it has 1. item 2. item 3. item 4. item Well, I am going through this my usual way, which is just brute force string manipulation. It’s still my first day with Ruby. Then I see str.scan Both forms iterate through str, matching the pattern (which may be a Regexp or a String). For each match, a result is generated and either added to the result array or passed to the block. If the pattern contains no groups, each individual result consists of the matched string, $&. If the pattern contains groups, each individual result is itself an array containing one entry per group. And I think, oooh, I bet that would be cool to use here. But my regexp is rusty and I’m not sure how I would set it up items = page.scan(’ - \* ’) something like that? Then items would be an array of the text in the items? Looked cool, anyway. I love how terse it can be. There’s probably also an html/xml parsing library, but I don’t have THAT much of this stuff to do, so I think a little manual work is probably simpler/easier to learn. –Colin ---
**Author:** ![banry](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/898d66/32.png) [@banry](https://www.ruby-forum.com/u/banry)\ **Post date:** [June 15, 2007, 8:14am UTC](https://www.ruby-forum.com/t/str-scan/106907/2 "2007-06-15T08:14:38Z")
Colin, But my regexp > is rusty and I’m not sure how I would set it up > items = page.scan(‘ > > - \* > ’) > something like that? Then items would be an array of the text in the items? Yes, they will be. However, first things first: 1. items = page.scan(‘ 2. \* ’) I believe you want instead is items = page.scan(‘ - .\* ’) ( or maybe items = page.scan(‘ - .+ ’) if you are not interested in empty - - .\*? ’) ? adds greediness to your regexp - so instead of matching the first - . then matching as much as possible of anything, then matching the \*last\* , 2) will match as less as possible. Let’s try: stuff = \<\ > stuff.scan(/ > > > > - .\*?\/) > > =\> [“ > > - aaa > > ”, “- bbb > > ”] 1. Maybe you want even this: > > stuff.scan(/ > > > > - (.\*?)\/) > > =\> [[“aaa”], [“bbb”]] or, even more friendly: > > stuff.scan(/ > > > > - (.\*?)\/).flatten > > =\> [“aaa”, “bbb”] HTH, Peter \_ [http://www.rubyrailways.com](http://www.rubyrailways.com) :: Ruby and Web2.0 blog [http://scrubyt.org](http://scrubyt.org) :: Ruby web scraping framework [http://rubykitchensink.ca/](http://rubykitchensink.ca/) :: The indexed archive of all things Ruby. ---
**Author:** ![banry](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/898d66/32.png) [@banry](https://www.ruby-forum.com/u/banry)\ **Post date:** [June 15, 2007, 10:37am UTC](https://www.ruby-forum.com/t/str-scan/106907/3 "2007-06-15T10:37:58Z")
> hpricot, mechanize, rexml, rubyful\_soup and if you decide you need something advanced, you could check out scRUBYt! as well. Cheers, Peter \_ [http://www.rubyrailways.com](http://www.rubyrailways.com) :: Ruby and Web2.0 blog [http://scrubyt.org](http://scrubyt.org) :: Ruby web scraping framework [http://rubykitchensink.ca/](http://rubykitchensink.ca/) :: The indexed archive of all things Ruby. ---
**Author:** ![banry](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/898d66/32.png) [@banry](https://www.ruby-forum.com/u/banry)\ **Post date:** [June 15, 2007, 10:20am UTC](https://www.ruby-forum.com/t/str-scan/106907/4 "2007-06-15T10:20:57Z")
Colin S. wrote: > There’s probably also an html/xml parsing library, There are a number of them. > but I don’t have > THAT much of this stuff to do, so I think a little manual work is > probably simpler/easier to learn. I doubt it. The html/xml parsing libraries that are available are very easy to learn. Here’s a few you could google for: ``` hpricot, mechanize, rexml, rubyful_soup ``` You can literally be up and running within minutes with one of those. cheers, mick ---
**Author:** ![banry](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/898d66/32.png) [@banry](https://www.ruby-forum.com/u/banry)\ **Post date:** [June 15, 2007, 5:06pm UTC](https://www.ruby-forum.com/t/str-scan/106907/5 "2007-06-15T17:06:15Z")
On Jun 15, 12:13 am, Peter S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > 1. What I really believe you want is > > items = page.scan(‘ > > - .\*? > ’) > > ? adds greediness to your regexp - so instead of matching the first > > - . then matching as much as possible of anything, then matching the \*last\* > , 2) will match as less as possible. Minor pedantic correction: .\* is greedy (it grabs as much as it can). The question mark makes it non-greedy (stop as soon as you’ve found a match). ---
**Author:** ![banry](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/898d66/32.png) [@banry](https://www.ruby-forum.com/u/banry)\ **Post date:** [June 15, 2007, 5:46pm UTC](https://www.ruby-forum.com/t/str-scan/106907/6 "2007-06-15T17:46:25Z")
stuff.scan(/ - is exactly what I was hoping for. I peeked at scRUBYt and I know that I am duplicating work in there, but I am trying to a bunch of things at once and one is learning Ruby. scRUBYt is doing so much work for me that I wouldn’t learn very much. - (.\*?)\/).flatten is so long. That’s great. Day 2: Have my pickaxe. Bought Pine’s book because it was fun to read on the web and I like having books. Bought another copy of Lenz’ Rails book because a friend like it so much he took it. 115 lines and I am ahead of where the professional consultant was with the .NET application (after a month of programming). Thanks, –Colin