From: Scott Rubin <slr2777@...>
Date: 2004-12-15T23:47:15+09:00
Subject: Regex extraction

Hello,

I'm writing an application that parses log files, specifically gaim html log 
files, extracts any links it finds and creates an RSS feed of those links.  I 
have a working program that's about 60 lines of ruby, but it is far from 
perfect.  Most of the necessary fixes and improvements are things I know how to 
do, but just take time. But there are a couple things I need help with.

First, in ruby, how do I extract parts of a regex?  Let's use the example from 
my program.  Normally I could use an expression like the following

  href\s*=\s*?:(\"?<url>[^\"]*)\")

And this would allow me to get the <url> out of the expression.  But this 
doesn't seem to work in ruby, or at least I don't know how to make it work in 
ruby.  What I would really like to do is match the entire <a href tag structure. 
  I would want to extract: the protocol (ftp,http) the url (www.website.com), 
and the text which appears between the <a> and the </a> into three string 
variables.  And I have to extract this entire structure from any random line of 
text in which the structure either exists or does not.  I'm guaranteed that it 
wont be partial i.e: an <a> without a </a>.

The other thing I don't know how to do is replace things like &amp; with &.  Is 
there anything in the ruby standard library, maybe in rexml, that automatically 
takes care of all those standard entities for me?  I looked, but I couldn't find 
one.

Thanks a lot,

Scott Rubin