gistfile1.rb

require 'rubygems'
require 'open-uri'
require 'yaml'
require 'mechanize'


ARCHIVE_PATH = '/tmp/images'
FileUtils.mkdir_p ARCHIVE_PATH

a = WWW::Mechanize.new { |agent| agent.user_agent_alias = 'Mac Safari'}

(0..10).each do |page_number|
  page_number = 'imgboard' if page_number == 0
  url = "http://img.4chan.org/b/#{page_number}.html"
  p "getting #{url}"
  a.get(url) do |page|
   page.links.each do |link|
     file_name = link.text.downcase
     next unless file_name =~ /[0-9]*\.(jpg|png|gif)/
     file_path = ARCHIVE_PATH + '/' + file_name
     if File.exists?(file_path)
       p "exists, skipping"
         next
       end
       file = link.click

       p "creating #{file_path}"
       File.open(file_path, "w+") do |f|
         f.syswrite(file.body)    
       end
    end
  end
end