How to save pictures from URL to disk - ruby-on-rails

Question

I want to download pictures from a URL, like: http://trinity.e-stile.ru/ and save images to a directory like "C:\pickaxe\pictures". It is important to use Nokogiri.
I read similar questions on this site, but I didn't find how it works and I didn't understand the algorithm.
I wrote the code where I parse the URL and put parts of the webpage source code with "img" tag into a links object:
require 'nokogiri'
require 'open-uri'
PAGE_URL="http://trinity.e-stile.ru/"
page=Nokogiri::HTML(open(PAGE_URL)) #parsing into object
links=page.css("img") #object with html code with img tag
puts links.length # it is 24 images on this url
puts
links.each{|i| puts i } #it looks like: <img border="0" alt="" src="/images/kroliku.jpg">
puts
puts
links.each{|link| puts link['src'] } #/images/kroliku.jpg
What method is used to save pictures after grabbing the HTML code?
How can I put the images into a directory on my disk?
I changed the code, but it has an error:
/home/action/.parts/packages/ruby2.1/2.1.1/lib/ruby/2.1.0/net/http.rb:879:in `initialize': getaddrinfo: Name or service not known (SocketError)
This is the code now:
require 'nokogiri'
require 'open-uri'
require 'net/http'
LOCATION = 'pics'
if !File.exist? LOCATION # create folder if it is not exist
require 'fileutils'
FileUtils.mkpath LOCATION
end
#PAGE_URL = "http://ruby.bastardsbook.com/files/hello-webpage.html"
#PAGE_URL="http://trinity.e-stile.ru/"
PAGE_URL="http://www.youtube.com/"
page=Nokogiri::HTML(open(PAGE_URL))
links=page.css("img")
links.each{|link|
Net::HTTP.start(PAGE_URL) do |http|
localname = link.gsub /.*\//, '' # left the filename only
resp = http.get link['src']
open("#{LOCATION}/#{localname}", "wb") do |file|
file.write resp.body
end
end
}

Answer 1

You are almost done. The only thing left is to store files. Let’s do it.
LOCATION = 'C:\pickaxe\pictures'
if !File.exist? LOCATION # create folder if it is not exist
require 'fileutils'
FileUtils.mkpath LOCATION
end
require 'net/http'
.... # your code with nokogiri etc.
links.each{|link|
Net::HTTP.start(PAGE_URL) do |http|
localname = link.gsub /.*\//, '' # left the filename only
resp = http.get link['src']
open("#{LOCATION}/#{localname}", "wb") do |file|
file.write resp.body
end
end
end
That’s it.

Answer 2

The correct version:
require 'nokogiri'
require 'open-uri'
LOCATION = 'pics'
if !File.exist? LOCATION # create folder if it is not exist
require 'fileutils'
FileUtils.mkpath LOCATION
end
#PAGE_URL="http://trinity.e-stile.ru/"
PAGE_URL="http://www.youtube.com/"
page=Nokogiri::HTML(open(PAGE_URL))
links=page.css("img")
links.each{|link|
uri = URI.join(PAGE_URL, link['src'] ).to_s # make absolute uri
localname=File.basename(link['src'])
File.open("#{LOCATION}/#{localname}",'wb') { |f| f.write(open(uri).read) }
}