school.rb

#!/usr/local/bin/ruby -Ks
# _*_ coding: utf-8 _*_

require 'rubygems'
require 'mechanize'
require 'time'

MAIL = 'mixi_login_mail_address'
PASS = 'mixi_login_pass'
DIRECTORY = 'log_directory_path'

# start mechanize
def login
    agent = WWW::Mechanize.new
    agent.user_agent_alias = 'Windows IE 7'
    page = agent.get('http://mixi.jp/')
    login_form = page.forms.first
    login_form['email'] = MAIL
    login_form['password'] = PASS
    login_form['next_url'] = '/home.pl'

    agent.submit(login_form)
    return agent
end

def get_populations(agent)
    res = Hash::new
    url = 'https://mixi.jp/edit_account_school.pl'
    page = agent.get(url)
    # tekitou
    res['elem'] = page.at('//div[@class="cl01"]/p/a').inner_text.match(/^.+\((\d+)\)$/)[1]
    res['junior'] = page.at('//div[@class="cl02"]/p/a').inner_text.match(/^.+\((\d+)\)$/)[1]
    res['high'] = page.at('//div[@class="cl03"]/p/a').inner_text.match(/^.+\((\d+)\)$/)[1]
    res['univ'] = page.at('//div[@class="cl04"]/p/a').inner_text.match(/^.+\((\d+)\)$/)[1]
    return res
end

def save2csv(res)
    res.each{|key, value|
        content = Time.now.strftime("%Y-%m-%d %H:%M:%S") + ', ' + value
        file = DIRECTORY + key + '.csv'
        f = File.open(file,'a+')
        f.puts content
        f.close
    }
end

agent = login
save2csv(get_populations(agent))