gistfile1.txt

require 'rubygems'
require 'mechanize'
require 'open-uri'

username = ''
password = ''

#Mechanizeの設定
agent = Mechanize.new
agent.user_agent_alias = 'Mac Safari'

#ログイン処理
page = agent.get('http://mixi.jp/')

form = page.forms[0]

form.fields.find {|f| f.name == 'email'}.value = username
form.fields.find {|f| f.name == 'password'}.value = password
form.fields.find {|f| f.name == 'next_url'}.value = '/home.pl'
results = agent.submit(form)

#対象コミュニティページのURL
url = ["http://mixi.jp/view_community.pl?id=1390708",
"http://mixi.jp/view_community.pl?id=657724",
"http://mixi.jp/view_community.pl?id=629852"
]

get_category = []

url.each do |a|

  agent.get(a).search('//dl[contains(concat(" ",@class," "), " categoryName ")]/dd').each do |b|    
    p b.text
  end                                                                         
                                                                              
end