Robert Klemme
12/15/2004 3:00:00 PM
"Scott Rubin" <slr2777@cs.rit.edu> schrieb im Newsbeitrag
news:41c04ca2$1@buckaroo.cs.rit.edu...
> 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>.
You need grouping. As a first shot:
if %r{<a\s+href="(\w+)://([^"]+)"[^>]*>([^<]*)</a>}i =~ text
proto, url, text = $1, $2, $3
end
> The other thing I don't know how to do is replace things like & 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.
Dunno. But you can easily create that on your own:
ENT = {
"amp" => "&",
"gt" => ">",
# ...
}
text.gsub!(%r{&(\w+);}i) {|m| ENT[$1] || m}
Kind regards
robert