stock_scraper.rb

require 'httparty'
require 'nokogiri'

loop do
    puts "Enter a stock identifier. Escape to exit."
    stock_ticker = gets.chomp

    if stock_ticker == "\e"
        break
    end
    puts ""

    response = HTTParty.get("http://finance.yahoo.com/q?s=#{stock_ticker.upcase}")
    dom = Nokogiri::HTML(response.body)
    stock_span = dom.xpath("//span[@id='yfs_l84_#{stock_ticker.downcase}']").first
    stock_prev = dom.xpath("//td[@class='yfnc_tabledata1']").first
    stock_open = dom.xpath("//td[@class='yfnc_tabledata1']")[1]

    print "Stock \"#{stock_ticker.upcase}\""

    if(stock_span.nil?)
        puts " cannot be found."
    else
        printf ": PREV CLOSE: $%.2f; OPEN - $%.2f; CURR: $%.2f", stock_prev.content, stock_open.content, stock_span.content
    end

    puts ""
end