Retrieve Paris RER A/B schedule from your terminal

rer.rb

require 'uri'
require 'net/http'
require 'net/https'
require 'nokogiri'

def get_stations(line)
  uri = URI("http://www.ratp.fr/horaires/fr/ratp/rer/choix-arret-direction/#{line}")
  response = Net::HTTP.get_response(uri)
  if response.is_a? Net::HTTPSuccess
    doc = Nokogiri::HTML(response.body)
    rows = doc.xpath("//select[@id='rerArretDirectionForm_station']/option/@value")
  else
    "Error retrieving stations list: #{response.message} (#{response.code})"
  end
end

def get_schedule(line, station, terminus)
  uri = URI("http://www.ratp.fr/horaires/fr/ratp/rer/prochains_passages/#{line}/#{station.gsub(/ /, '+')}/#{terminus}")
  response = Net::HTTP.get_response(uri)

  if response.is_a? Net::HTTPSuccess
    doc = Nokogiri::HTML(response.body)
    rows = doc.xpath("//div[@id='prochains_passages']//tbody/tr")
    rows.each do |row|
      puts "%4s | %-26s | %s" % row.xpath("./td").map{|col| col.content.strip}
    end
  elsif response.is_a? Net::HTTPFound
    raise "Real-time service information not available"
  else
    raise "Error retrieving service information: #{response.message} (#{response.code})"
  end
end

terminus = {
  "RA" => {
    "A" => "St-Germain-en-Laye/Poissy/Cergy",
    "R" => "Boissy-St-Léger/Marne-la-Vallée",
  },
  "RB" => {
    "A" => "Charles-de-Gaulle/Mitry-Claye",
    "R" => "Robinson/Saint-Rémy-lès-Chevreuse",
  }
}

header = <<-EOF
--------------------------------------------------------
Name | Terminus                   | Time
--------------------------------------------------------
EOF

begin
  puts "From Arcueil Cachan, Terminus #{terminus["RB"]["A"]}"
  puts header
  get_schedule("RB", "Arcueil Cachan", "A")
  puts
  puts "From Chatelet, Terminus #{terminus["RB"]["R"]}"
  puts header
  get_schedule("RB", "Chatelet", "R")
rescue Exception => e
  puts e.message
end

#puts get_stations("RA")

result.txt

$ ruby rer.rb

From Arcueil Cachan, Terminus Charles-de-Gaulle/Mitry-Claye
--------------------------------------------------------
Name | Terminus                   | Time
--------------------------------------------------------
EMUR | Aeroport Ch.De Gaulle 2    | Train à quai
ILOU | Mitry-Claye                | 19:52
EBOI | Aeroport Ch.De Gaulle 2    | Train sans arrêt
EMUR | Aeroport Ch.De Gaulle 2    | 20:02
IDRE | Mitry-Claye                | Train sans arrêt
ILOU | Mitry-Claye                | 20:00

From Chatelet, Terminus Robinson/Saint-Rémy-lès-Chevreuse
--------------------------------------------------------
Name | Terminus                   | Time
--------------------------------------------------------
KUNE | Massy Palaiseau            | Train à l'approche
SOUS | Robinson                   | 19:52
PAKE | Saint Remy les Chevreuse   | 19:54
LEVI | Orsay Ville                | 19:52
KUNE | Massy Palaiseau            | 19:58
SOUS | Robinson                   | 20:00