Get all links from website using Hpricot

links.rb

require 'rubygems'
require 'hpricot'
require 'open-uri'

doc = Hpricot(open("http://7thoughts.com/links.html"))
myfile = File.new('links.html', 'w+')
doc.search("a[@href]").each do |param|
  param = param.to_s
  unless param =~ /\.pdf/i
    myfile.puts(param)
  end
end

# or raggi's variant ( from irc )
Hpricot(open('http://www.google.com')).search('a[@href]').reject{|e| e['href'] =~ /\.pdf$/ }