downloads the latest edition of the excellent magazine from the guys at pragprog and pushes it to your kindle

pragprogmagazine-downloader.rb

#!/usr/bin/env ruby
# Quick rough and dirty script to push new issues of the excellent
# free monthly magazine from the guys at PragProg to your kindle
#
# Will download the latest magazine from the list and then will only
# download magazines when a new issue comes out
#
require 'date'
require 'fileutils'
require 'nokogiri'
require 'open-uri'
SETTINGS_FILE = File.expand_path('~/.pragprogmagazines2kindle-settings')

def get_last_issue_no
  last_issue = 0
  File.open(SETTINGS_FILE,'r') do |file|
    last_issue = file.gets
  end
  return last_issue.to_i
end

begin

  doc = Nokogiri::HTML(open('http://pragprog.com/magazines'))
  issue_nos = []
  doc.css('table.magazines h3').each do |issue| issue_nos << issue.content.chomp.strip.slice(6..100)[0..1].to_i end
  latest_issue = issue_nos.max
  puts DateTime.now.strftime('%d/%m/%Y %H:%M:%S')
  puts "-"*80
  puts "Latest issue is ##{latest_issue}"

  last_issue = File.exists?(SETTINGS_FILE) ? get_last_issue_no : 0
  puts "Last issue retrieved was ##{last_issue}" if last_issue > 0

  if latest_issue > last_issue
    puts "New issue found! Downloading..."

    #construct a filepath
    filename = latest_issue.to_s << ".mobi"
    magazine_link = "http://pragprog.com/magazines/download/" << filename
    filepath = File.expand_path("~/" << filename)

    #download
    puts "\n"
    %x(wget #{magazine_link} -O #{filepath})
    puts

    #use kindlemail to send document
    system("kindlemail #{filepath}")

    #remove file from filesystem
    FileUtils.rm(filepath)

    File.open(SETTINGS_FILE,'w') do |file| file.write latest_issue end
  else
    puts "No new issues found"
  end
  puts
end