DZone Snippets: Jnewland's Code Snippets

Restore a single table from a large MySQL backup

jnewland (Jesse Newland) — Wed, 28 Nov 2007 14:10:03 GMT

Say, for some reason, you need to restore the entire contents of a single table from a HUGE mysqldump generated backup containing several tables. For example:



create table `baz`;



GIGS OF SQL YOU DON'T WANT;



create table `foo`;



A COUPLE THOUSAND LINES YOU DO WANT;



create table `bar`;



MORE SQL YOU DON'T WANT;

With a little dash 'o ruby, you can extract just the part you want:



$ ruby -ne '@found=true if $_ =~ /^CREATE TABLE `foo`/i; next unless @found; exit if $_ =~ /^CREATE TABLE (?!`foo`)/i; puts $_;' giant_sql_dump.sql > foo.sql

$ cat foo.sql

create table `foo`;



A COUPLE THOUSAND LINES YOU DO WANT;

You can then easily restore that entire table:



$ mysql mydatabase -e 'drop table foo'

$ mysql mydatabase < foo.sql

open_body_tag

jnewland (Jesse Newland) — Thu, 01 Nov 2007 19:24:01 GMT



  #creates a body tag uniquely indentifying this page

  #takes an options Hash with two keys:

  #

  #id::        string that will be used as the body's ID. defaults to controller.controller_name.singularize

  #classes::   an Array of class names. defaults to [params[:action]]

  #

  #Examples:

  #

  # in HomeController#index:

  #

  # <%= open_body_tag %>

  # => 

  #

  # <%= open_body_tag(:id => 'foo') %>

  # => 

  #

  # <%= open_body_tag(:id => 'foo', :classes => %w(one two)) %>

  # => 

  def open_body_tag(options = { :id => controller.controller_name.singularize, :classes => [params[:action]] })

    ""

  end

Test Trackback using cURL

jnewland (Jesse Newland) — Fri, 14 Sep 2007 01:31:16 GMT

I've Googled this about 20 times - documenting it here for convenience.



curl -d url=TRACKBACK_URL -d title=TRACKBACK_TITLE -d blog_name=TRACKBACK_BLOG_NAME -d excerpt=TRACKBACK_EXCERPT URL

A correct response:

Rails URL Validation

jnewland (Jesse Newland) — Wed, 12 Sep 2007 14:03:00 GMT

No regexes, allows URLs with ports or IPs. Inspiration from here



  validates_each :href, :on => :create do |record, attr, value|

    begin

      uri = URI.parse(value)

      if uri.class != URI::HTTP

        record.errors.add(attr, 'Only HTTP protocol addresses can be used')

      end

    rescue URI::InvalidURIError

      record.errors.add(attr, 'The format of the url is not valid.')

    end

  end

Mofo - Parse Microformats with Ruby

jnewland (Jesse Newland) — Fri, 30 Mar 2007 16:58:34 GMT



$ sudo gem install mofo 

Successfully installed mofo-0.2.1

$ irb -rubygems

>> require 'mofo'

=> true

>> HResume.find("http://resume.jnewland.com").tags.uniq.sort

=> ["AJAX", "Apache", "CSS", "Capistrano", "DNS", "GNU/Linux", "HTML", "Javascript", "LAMP", "Mongrel", "Movable Type", "MySQL", "PHP", "Perl", "REST", "RSS", "Ruby", "Ruby on Rails", "SEO", "XHTML", "XML", "XSLT", "high availability", "lighttpd", "load-balanced"]

RSS Twitter Bot

jnewland (Jesse Newland) — Thu, 22 Mar 2007 04:20:12 GMT

Republish an RSS feed on a twitter account. This was the source I used to run the Woot Twitter Bot before they took it over.



require 'rubygems'

require 'active_record'

require 'simple-rss'

require 'open-uri'

require 'twitter'



#twitter account to post to

twitter_email = "yourtwitteremail@bla.com"

twitter_password = "secret"



#rss feed to post

rss_url = "http://yoursite.com/index.xml"

rss_user_agent = "http://twitter.com/yourbot"



#sqlite db

path_to_sqlite_db = "/PATH/TO/db.sqlite"





ActiveRecord::Base.logger = Logger.new(STDERR)

ActiveRecord::Base.colorize_logging = false



ActiveRecord::Base.establish_connection(

    :adapter => "sqlite3",

    :dbfile  => path_to_sqlite_db

)



#uncomment this section the first time to create the table

#

#ActiveRecord::Schema.define do

#    create_table :item do |table|

#        table.column :title, :string

#        table.column :link, :string

#    end

#end



class Item < ActiveRecord::Base

  def to_s

    "#{self.title[0..(130-self.link.length)]} - #{self.link}"

  end

end



#run the beast

rss_items = SimpleRSS.parse open(rss_url ,"User-Agent" => rss_user_agent)



for item in rss_items.items

  Item.transaction do

    unless existing_item = Item.find(:all, :conditions => ["link=?", item.link]).first

      twitter ||= Twitter::Base.new(twitter_email, twitter_password)

      new_item = Item.create(:title => item.title, :link => item.link) 

      twitter.post(new_item.to_s)

    end

  end

end

Run this once with the lines uncommented to create the DB, then slap it in your crontab.

Repair Spy

jnewland (Jesse Newland) — Mon, 26 Feb 2007 16:38:54 GMT

Takes a screenshot and a webcam snapshot and emails them to flickr. Requires isightcapture. Hacked up to spy on the Apple repair team as they try to repair my Mac Book Pro's backlight for the second time.



#!/bin/bash

# requires isightcapture http://www.intergalactic.de/hacks.html



# path to save the images

PATH=/Users/default/



# flickr email address

EMAIL="yourflickremail+private@photos.flickr.com"



# tags to attach to each picture uploaded

TAGS="repair_spy"



TIMESTAMP=`/bin/date "+%y%m%d%H%M%S"`

FRIENDLY_TIMESTAMP=`/bin/date "+%Y/%m/%d %H:%M"`



#take pics

/usr/sbin/screencapture -mxC $PATHscreen_$TIMESTAMP.png

/usr/local/bin/isightcapture -t png $PATHisight_$TIMESTAMP.png



#post to flickr

/usr/bin/uuencode $PATHscreen_$TIMESTAMP.png $PATHscreen_$TIMESTAMP.png | /usr/bin/mail -s "Repair Spy Screenshot - $FRIENDLY_TIMESTAMP tags: $TAGS" $EMAIL

/usr/bin/uuencode $PATHisight_$TIMESTAMP.png $PATHisight_$TIMESTAMP.png | /usr/bin/mail -s "Repair Spy iSight Cature - $FRIENDLY_TIMESTAMP tags: $TAGS" $EMAIL

Toss this in your crontab like so, making sure to run it as the user that you provide to the Apple Techs



*/1    *       *       *       *       default /Users/default/repair_spy >& /dev/null

Ruby One Time Web Server

jnewland (Jesse Newland) — Wed, 07 Feb 2007 23:45:38 GMT

An interpretation of OneTimeWebServer in Ruby. OneTimeWebServer holds a single "page" in memory, serves it to the first visitor, and evaporates. Useful for all sorts of hijinks.



#!/usr/local/bin/ruby

require 'socket'

t = STDIN.read

while s = TCPServer.new('127.0.0.1', (ARGV[0] or 8080)).accept

  puts s.gets

  s.print "HTTP/1.1 200/OK\rContent-type: text/plain\r\n\r\n" + t

  s.close

  exit

end

Usage:



echo "test" | ./otws.rb [optional port number, defaults to 8080]

Or for recursive fun:



cat otws.rb | ./otws.rb [optional port number, defaults to 8080]

Export del.icio.us links to MT Import Format

jnewland (Jesse Newland) — Wed, 31 Jan 2007 18:36:51 GMT

A friend of mine needed his del.icio.us links in MT Import format for some reason. This solved that problem.



require 'rexml/document'

require 'net/https'

require 'rubygems'



# change credentials!

user = 'username'

pass = 'password'



# User-Agent: required for del.icio.us api

agent = 'delicious-mt'

xml = ''



http = Net::HTTP.new('api.del.icio.us', 443)

http.use_ssl = true

http.start do |http|

  request = Net::HTTP::Get.new('/v1/posts/all', {'User-Agent' => agent})

  request.basic_auth(user, pass)

  response = http.request(request)

  response.value

  xml = response.body

end

 

REXML::Document.new(xml).elements.each('posts/post') do |el|

  puts "TITLE: #{el.attributes['description']}"

  puts "AUTHOR: Author Name"

  puts "DATE: #{DateTime.parse(el.attributes['time']).strftime("%m/%d/%Y %H:%M:%S")}"

  puts "-----"

  puts "BODY:"

  puts el.attributes['extended']

  puts "-----"

  puts "EXCERPT:"

  puts el.attributes['href']

  puts "KEYWORDS:"

  puts el.attributes['tag']

  puts "-----"

  puts "--------"

end

Synchronizing Rails DB Contents via Fixtures

jnewland (Jesse Newland) — Wed, 31 Jan 2007 01:04:37 GMT

The following rake task will dump the contents of the current environment's database to YAML fixtures. Stick the following in lib/tasks/fixtures.rake:



namespace :db do

  namespace :fixtures do

    

    desc 'Create YAML test fixtures from data in an existing database.  

    Defaults to development database.  Set RAILS_ENV to override.'

    task :dump => :environment do

      sql  = "SELECT * FROM %s"

      skip_tables = ["schema_info"]

      ActiveRecord::Base.establish_connection(:development)

      (ActiveRecord::Base.connection.tables - skip_tables).each do |table_name|

        i = "000"

        File.open("#{RAILS_ROOT}/test/fixtures/#{table_name}.yml", 'w') do |file|

          data = ActiveRecord::Base.connection.select_all(sql % table_name)

          file.write data.inject({}) { |hash, record|

            hash["#{table_name}_#{i.succ!}"] = record

            hash

          }.to_yaml

        end

      end

    end

  end

end

After making changes to the database that you'd like to dump to fixtures:



rake db:fixtures:dump

After checking out updated fixtures from SVN:



rake db:migrate

rake db:fixtures:load