# encoding: utf-8require 'thread'require 'nokogiri'require 'open-uri'require 'rss/maker' $result=Queue.newdef extract_readme_header(no,name,url) frame = Nokogiri::HTML(open(url)) return unless frame readme=$url+frame.css('frame')[1]['src'] return unless readme open(readme) do |f| doc = Nokogiri::HTML(f.read) text=doc.css("div#content div#filecontents p")[0..4].map { |c| c.content }.join(" ").strip return if text.length==0 if text !~ /(rails)|(activ_)/i puts "========= #{no} #{name} : #{text[0..50]}" date = f.last_modified $result << [no,name,readme,date,text] end endrescue puts $!.to_send def make_rss(items) RSS::Maker.make("2.0") do |m| m.channel.title = "GtitHub recently updated projects" m.channel.link = "http://localhost" m.channel.description = "GitHub recently updated projects" m.items.do_sort = true items.each do |no,name,url,date,descr| i = m.items.new_item i.title = name i.link = url i.description=descr i.date = date end endend ############################## M A I N ######################## ############# Scan list of recent project lth=[]$url="http://rdoc.info"puts "get url #{$url}..."doc = Nokogiri::HTML(open($url))doc.css('ul.libraries')[1].css('li').each_with_index do |li,i| aname =li.css('a').first name=aname.content purl=$url+aname['href'] lth << Thread.new(i,name,purl) { |j,n,u| extract_readme_header(j,n,u) }end ################ wait all readme are read lth.each { |th| th.join() } ################ dequeue results and sort them by date descending result=[]result << $result.shift while $result.size>0result.sort! { |a,b| a[0] <=> b[0] } ################ format results in rss File.open("RubyFeeds.rss","w") do |file| file.write make_rss(result)end以上就是使用Ruby和Nokogiri模拟爬虫导出RSS种子的实例详解的知识。速戳>>知识兔学习精品课！