这是一个实现在命令行登录和注销校园网的小脚本。

auto-login.rb

# encoding = utf-8
require 'mechanize'
class Internet
  # 定义自动登录的地址
  @@url = 'http://192.168.31.4:8080'

  #初始化，生成一个Mechanize对象
  def initialize
    @agent = Mechanize.new
  end

  # 获取当前页面的表单
  def get_form
    @page = @agent.get(@@url)
    @current_form = @page.form('AuthenticateForm')
  end

  # 登录
  def login
    get_form
    if @current_form.submit_button?('Submit') # 如果有登录按钮，就执行登录动作，否则提示已经登录
      @login_form = @current_form
      @login_form.AuthenticateUser = $USERNAME
      @login_form.AuthenticatePassword = $PASSWORD
      @logout_form = @agent.submit(@login_form).form('AuthenticateForm')
      if @logout_form.submit_button?('Logout')   # 如果登录成功，就显示成功提示，否则重复登录动作
        puts "Login Success."
      else
        login
      end
    else
      puts "You have already login!"
    end
  end

  #注销
  def logout
  get_form
    if @current_form.submit_button?('Logout')  # 如果有注销按钮，就执行注销动作，否则提示还没登录
      @logout_form = @current_form
      @login_form = @agent.submit(@logout_form, @logout_form.buttons.first).form('AuthenticateForm')
      if @login_form.submit_button?('Submit')  # 如果注销成功，就显示成功提示，否则重复注销动作
        puts "Logout Success."
      else
        logout
      end
    else
      puts "You haven't login yet!"
    end
  end

  # 查询流量
  def check_bytes
    get_form
    if @current_form.submit_button?('Logout')   # 如果有注销按钮，就执行查询动作，否则提示还没登录
      used_bytes = @page.search("#ub").text.gsub(/,/,"").to_i  # 搜索页面中的元素，找到id为"#ub"的元素
      puts "---------------"
      puts "Used: #{used_bytes/1024/1024 + 1}MB"               # 把 byte 转成 MB
      total_bytes = @page.search("#tb").text.gsub(/,/,"").to_i
      left_bytes = total_bytes - used_bytes
      puts "Left: #{left_bytes/1024/1024}MB"
      puts "---------------"
    else
      puts "You haven't login yet!"
    end
  end
end

stu = Internet.new
stu.login       #登录
stu.check_bytes #查询流量
stu.logout      #注销