Ideas, Theory, Computers, WEB, Mobile, Products

1. If you stop the script in between manually, it will not download those screencasts that are already in your hard disk.
2. All logs are maintained in Railsproject/log/railscasts.log.
3. Handling all exceptions raised

Improvements/Suggestions  are appreciated.

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</pre>

<pre># Author : Akshay Gupta</pre>

<pre>#file: railscasts.rb

# First check you have all gems installed. Place the script in /lib folder and run the script.

# I don't have expertize in ruby, please tell how it can be improved.

# change the path accordingly, where you want to save path

# My working env is on MacOS, one need to make some changes if running on Windows

<code>

require 'rubygems'

require 'hpricot'

require 'open-uri'

require 'logger'

$log = Logger.new('log/railscasts.log')

$path = "/Users/akshaygupta/railsvideo/railscasts/"

$stop = false



class Railscasts

attr_accessor :url



def initialize

  @@page = 1

  @@url  = "http://railscasts.com/episodes?page="

  start

end



def url

  @url = @@url+@@page.to_s

end



def start

  url

  build_doc

  screencasts_links

  download_screencasts

  next_page

  if !$stop

    start

  else

    puts "Successfully done :) Enjy all the screencasts"

  end

end



def build_doc

  begin

    $log.info("*********Fetching #{@url}***********")

    @doc = Hpricot(open(@url))

  rescue Exception =&gt; e

    $log.debug("Problem fetching #{e}")

  end

end



def screencasts_links

  begin

    @download_links =

      (@doc/".download/a[1]").collect {|a| (a.search("[@href]").first[:href])}

    $log.info(" All Download links on this page :\n #{@download_links}")

  rescue

    $log.info("Problem in download links")

  end

end



def download_screencasts

  @download_links.each do |mov|

    begin

      file = mov.split('/').last

      res = `cd #{$path}; ls | grep "#{file}"`

      if !res

        $log.info("Now downloading file #{file}")

        result = `cd #{$path}; wget "#{mov}"`

        if result

          $log.info("Successfully Downloaded #{file}")

        end

      else

        $log.info("Already downloaded #{file}")

      end

    rescue Exception =&gt; e

      $log.info("problem downloding file #{e}")

    end

  end

end



  def next_page

    if @@page &lt; 17

      @@page += 1

    else

      $log.info("All screencasts downloaded :-), Mission accomplished!!")

      $stop = true

    end

  end

end</code></pre>

<pre><span style="font-family: monospace;">