dougsparling.org (kl93)

HTTP Load Testing/Tsung

2009-08-14T12:08:00.000-07:00

I'm reviewing a few open source tools for load testing for a project at work. We selected Tsung, an open-source multi-protocol distributed load testing tool written in Erlang. I'll go into Tsung in more depth in a later post, but for now I'll list several resources that I've found helpful.

Tsung

Tsung

Google Video: Erlang eXchange 2008: Tsung Tutorial - Mickael Remond

The Tsung-users Archives

Test the Performance and Scalability of Your Web Applications With Tsung

Using Tsung for Load Testing Rails or Web Apps

Load Testing

RailsLab: Scaling Rails - Episode #15 - Load Testing - Part 1

RailsLab: Scaling Rails - Episode #16 - Load Testing - Part 2

Linux.com - Using free software for HTTP load testing (2006)

Linux.com - Stress testing an application with JMeter (2004)

Server Fault - Tools for load-testing HTTP servers?

Open Source Testing Tools

Google Testing Blog - Performance Testing (Goranka Bjedov)

Google Video: Using open source tools for performance testing (Google Tech Talk - Goranka Bjedov)

Real-World Load Testing Tips to Avoid Bottlenecks When Your Web App Goes Live

patterns & practices: Performance Testing Guidance

New Blogs - scriptrunner.com, Learning Erlang

2009-05-21T17:05:00.000-07:00

I'll be posting all Ruby, Rails, and related topics at my new blog, http://www.scriptrunner.com/ (and I'll probably move over my old posts as well)

I'm also getting ready to start another new blog, "Learning Erlang," currently located at http://learningerlang.blogspot.com/ which I may move it to its own domain once I get started.

Rails & Testing - Resources

2009-02-06T10:07:00.000-08:00

This is an in-progress set of testing resources aimed at the Ruby/Rails developer...

Rails Guides

http://guides.rubyonrails.org/testing_rails_applications.html

nullislove.com

Nginx, Mongrel, Merb

2008-11-18T16:10:00.000-08:00

Quick notes on installing and configuring nginx and running with existing mongrel and Merb app on my MacBookPro.

1) Download and install PCRE (if needed)
http://www.pcre.org/
ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/
ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-7.8.tar.gz

$ ./configure
$ ./make
$ ./make install

2) Download and install nginx:
http://nginx.net/
The latest stable version is nginx-0.6.32, the change log.
http://sysoev.ru/nginx/nginx-0.6.32.tar.gz

$ ./configure
$ ./make
$ ./make install

# Edit nginx.conf file (/usr/local/nginx/conf/nginx.conf)
# Note - based on Ezra's blog post (see notes below)


user  nobody;
worker_processes  2;

error_log  logs/error.log notice;
pid        logs/nginx.pid;

events {
    worker_connections  1024;
}

http {
    include       mime.types;
    #include       conf/mime.types;
    default_type  application/octet-stream;

    # no sendfile on OSX uncomment 
    #this if your on linux or bsd
    #sendfile        on;
    tcp_nopush     on;

    keepalive_timeout  65;
    tcp_nodelay        on;

    upstream mongrel {
        server 127.0.0.1:4000;
        server 127.0.0.1:4001;
        server 127.0.0.1:4002;
    }

    gzip on;
    gzip_min_length  1100;
    gzip_buffers     4 8k;
    gzip_types       text/plain;

    server {
        listen       80;
        #server_name  localhost;
        root /Users/dsparlingimbp/git/dougsparlingdotcom/public;

        access_log  off;
        rewrite_log on;

        location ~ ^/$ {
          if (-f /index.html){
            rewrite (.*) /index.html last;
          }
           proxy_pass  http://mongrel;
        }

        location / {
          if (!-f $request_filename.html) {
            proxy_pass  http://mongrel;
          }
          rewrite (.*) $1.html last;
        }

        location ~ .html {
           root /Users/dsparlingimbp/git/dougsparlingdotcom/public;
        }

           location ~* ^.+\.(jpg|jpeg|gif|png|ico|css|zip|tgz|gz|rar|bz2|doc|xls|exe|pdf|ppt|txt|tar|mid|midi|wav|bmp|rtf|js|mov)$ {
          root /Users/dsparlingimbp/git/dougsparlingdotcom/public;
        }

        location / {
            proxy_pass  http://mongrel;
            proxy_redirect     off;
            proxy_set_header   Host             $host;
            proxy_set_header   X-Real-IP        $remote_addr;
            proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;
        }

    }
}

4) Commands for starting and stopping nginx
start: sudo /usr/local/nginx/sbin/nginx
stop: sudo kill `cat /usr/local/nginx/logs/nginx.pid`

5) Start Mongrel cluster (I'm using 3 Mongrels):
$ merb -c 3
or
$ merb -p 4000 -c 3

6) Resources
http://brainspl.at/articles/2006/08/23/nginx-my-new-favorite-front-end-for-mongrel-cluster
http://articles.slicehost.com/2008/5/13/ubuntu-hardy-installing-nginx-from-source
http://articles.slicehost.com/2008/5/13/ubuntu-hardy-adding-an-nginx-init-script
http://articles.slicehost.com/2008/4/25/ubuntu-hardy-setup-page-1
http://articles.slicehost.com/2008/4/25/ubuntu-hardy-setup-page-2
http://forum.slicehost.com/comments.php?DiscussionID=2179
http://merb.rubyforge.org/files/README.html

Ruby - Randomize arrays and strings

2008-11-09T05:42:00.000-08:00

Randomize the elements of an array:


random_array = my_array.sort_by{rand}

Randomize a string (jumble a given word):


jumbled_word = word.split("").sort_by{rand}.join

Updating to RubyGems 1.3.0 on Mac OS X Leopard 10.5.4

2008-11-08T04:33:00.000-08:00

When attempting to stall final release of Merb 1.0, I got an error message that I needed RubyGems version >=1.3.0:


ERROR:  Error installing merb:
 merb-core requires RubyGems version >= 1.3.

So I did the usual "gem update --system" but got an error:


$ sudo gem update --system
Password:
Updating RubyGems
Updating rubygems-update
Successfully installed rubygems-update-1.3.0
ERROR:  While executing gem ... (NameError)
    undefined local variable or method `remote_gemspecs' for #
$ gem --version
1.2.0

I found that you have to run a second set of instructions:


$ sudo gem install rubygems-update
Successfully installed rubygems-update-1.3.0
1 gem installed
$ sudo update_rubygems 
Installing RubyGems 1.3.0

More info here:
http://rails.wincent.com/wiki/Updating_to_RubyGems_1.3.0_on_Mac_OS_X_Leopard_10.5.4

Dynamic Details Row in GridView

2008-08-27T10:18:00.000-07:00


<%@ Page Language="C#" %>
<%@ Import Namespace="System.Web.Configuration" %>

<script runat="server">
    
    void GridView1_PreRender(object sender, EventArgs e)
    {
        if (GridView1.SelectedRow != null)
        {
            Table table = GridView1.SelectedRow.Parent as Table;

            if (table != null)
                CreateRow(table, GridView1.SelectedIndex);
        }
    }

    void CreateRow(Table table, int index)
    {
        GridViewRow row = new GridViewRow(-1, -1, DataControlRowType.DataRow, DataControlRowState.Normal);
        row.Cells.Add(CreateColumn());
        table.Rows.AddAt(index + 2, row);
    }

    private TableCell CreateColumn()
    {
        TableCell cell = new TableCell();
        cell.ColumnSpan = GridView1.Columns.Count;
        cell.Width = Unit.Percentage(100);

        DataSourceControl ds = CreateDataSourceControl();
        
        cell.Controls.Add(ds);
        cell.Controls.Add(CreateDetailsView(ds));    
        return cell;
    }

    private static DetailsView CreateDetailsView(DataSourceControl ds)
    {
        DetailsView dv = new DetailsView();
        dv.AutoGenerateRows = true;
        dv.DataSourceID = ds.ID;
        return dv;
    }

    private DataSourceControl CreateDataSourceControl()

    {
        SqlDataSource ds = new SqlDataSource();
        ds.ConnectionString = WebConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString;
        ds.SelectCommand = "SELECT * FROM [Users] WHERE [UserID] = @UserID";
        ds.ID = "SqlDataSource2";
        
        Parameter cp = new Parameter("UserID", TypeCode.String, GridView1.SelectedValue.ToString());
        ds.SelectParameters.Add(cp);
        return ds;
    }   
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >

<head id="Head1" runat="server">
    <title>Untitled Page</title>
</head>

<body>
    <form id="form1" runat="server">
    <div>

         <asp:GridView ID="GridView1" Runat="server" DataSourceID="SqlDataSource1" DataKeyNames="UserID"
            AutoGenerateColumns="False" OnPreRender="GridView1_PreRender" EnableViewState="False">
            <Columns>
                <asp:CommandField ShowSelectButton="True">
                <asp:BoundField ReadOnly="True" HeaderText="UserID" DataField="UserID" SortExpression="UserID">
                <asp:BoundField HeaderText="UserName" DataField="UserName" SortExpression="UserName"></asp:BoundField>
            </Columns>
        </asp:GridView>

        <asp:SqlDataSource ID="SqlDataSource1" Runat="server" SelectCommand="SELECT [UserID], [UserName] FROM [Users]"
            ConnectionString="<%$ ConnectionStrings:MyConnectionString %>">
        </asp:SqlDataSource>

    </div>
    </form>

</body>
</html>

Amazon S3 with Ruby aws-s3 gem

2008-08-23T17:58:00.000-07:00

I stated using Amazon S3 to store and backup the music I've written and recorded. I'm using the Ruby aws-s3 gem. Note that I check for some basic audio file types so I don't have to manually type the bucket or mime-type.


aws-s3.rb
---------
#!/usr/bin/env ruby
require 'rubygems'
require 'aws/s3'

# File to upload
local_file = ARGV[0]

# bucket & mime-type
if local_file =~ /mp3$/
  bucket = 'doug_mp3'
  mime_type = 'audio/mpeg'
elsif local_file =~ /wav$/
  bucket = 'doug_wav'
  mime_type = 'audio/x-wav'
elsif local_file =~ /aif[c|f]?$/
  bucket = 'doug_aiff'
  mime_type = 'audio/x-aiff'
else
  bucket = ARGV[1]
  mime_type = ARGV[2] || "application/octet-stream"
end 

if bucket.nil?
  puts "need a bucket"
  exit
end

puts "file: #{local_file}"
puts "bucket: #{bucket}"
puts "mime_type: #{mime_type}"

AWS::S3::Base.establish_connection!(
  :access_key_id     => 'REPLACE_ME',
  :secret_access_key => 'REPLACE_ME'
)

base_name = File.basename(local_file)
 
puts "Uploading #{local_file} as '#{base_name}' to '#{bucket}'"

AWS::S3::S3Object.store(
  base_name,
  File.open(local_file),
  bucket,
  :content_type => mime_type
)
 
puts "Uploaded!"

I can call the script a couple ways:

# with defaults based on extension
$ ruby aws-s3.rb mysong.mp3

# or explicitly (file, bucket, mime-type)
$ ruby aws-s3.rb mysong.mp3 doug_mp3 'audio/mp3'

Add and remove a remote source from gem 'remote sources''

2008-08-23T16:33:00.000-07:00

I was attempting to add a gem and ran into an error I hadn't seen before:


Macintosh:aws-s3 dsparlingimbp$ sudo gem i aws-s3
WARNING:  RubyGems 1.2+ index not found for:
        http://merbivore.com

RubyGems will revert to legacy indexes degrading performance.
Updating metadata for 63 gems from http://gems.rubyforge.org/
...............................................................
complete
ERROR:  could not find gem aws-s3 locally or in a repository

So I tried to update gems:


Macintosh:aws-s3 dsparlingimbp$ sudo gem update --system
Updating RubyGems
WARNING:  RubyGems 1.2+ index not found for:
 http://merbivore.com

RubyGems will revert to legacy indexes degrading performance.
Updating metadata for 63 gems from http://gems.rubyforge.org/
...............................................................
complete
ERROR:  While executing gem ... (Gem::RemoteFetcher::FetchError)
    bad response Not Found 404 (http://merbivore.com/Marshal.4.8)

Next I looked the gems environment:


Macintosh:rubygems-1.2.0 dsparlingimbp$ gem env
RubyGems Environment:
  - RUBYGEMS VERSION: 1.2.0
  - RUBY VERSION: 1.8.6 (2007-03-13 patchlevel 0) [i686-darwin8.8.5]
  - INSTALLATION DIRECTORY: /usr/local/lib/ruby/gems/1.8
  - RUBY EXECUTABLE: /usr/local/bin/ruby
  - EXECUTABLE DIRECTORY: /usr/local/bin
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86-darwin-8
  - GEM PATHS:
     - /usr/local/lib/ruby/gems/1.8
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :benchmark => false
     - :backtrace => false
     - :bulk_threshold => 1000
     - :sources => ["http://gems.rubyforge.org", "http://merbivore.com"]
  - REMOTE SOURCES:
     - http://gems.rubyforge.org
     - http://merbivore.com

Noticing the issues with Merb (which I recently installed), I removed http://merbivore.com from the list of remote sources:


sudo gem sources -r http://merbivore.com

I went ahead and added github while I was at it:


sudo gem sources -a http://gems.github.com

Checked my gems environment:


Macintosh:rubygems-1.2.0 dsparlingimbp$ gem env
RubyGems Environment:
  - RUBYGEMS VERSION: 1.2.0
  - RUBY VERSION: 1.8.6 (2007-03-13 patchlevel 0) [i686-darwin8.8.5]
  - INSTALLATION DIRECTORY: /usr/local/lib/ruby/gems/1.8
  - RUBY EXECUTABLE: /usr/local/bin/ruby
  - EXECUTABLE DIRECTORY: /usr/local/bin
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86-darwin-8
  - GEM PATHS:
     - /usr/local/lib/ruby/gems/1.8
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :benchmark => false
     - :backtrace => false
     - :bulk_threshold => 1000
     - :sources => ["http://gems.rubyforge.org", "http://gems.github.com"]
  - REMOTE SOURCES:
     - http://gems.rubyforge.org
     - http://gems.github.com

Everything looked good, so I tried to install aws-s3 gem again:


Macintosh:rubygems-1.2.0 dsparlingimbp$ sudo gem install aws-s3
Successfully installed aws-s3-0.5.1
1 gem installed
Installing ri documentation for aws-s3-0.5.1...
Installing RDoc documentation for aws-s3-0.5.1...

Et Voilà! C'est si bon...

authentication token

2008-07-26T18:21:00.000-07:00

I had a need to both validate the source of data sent to a web service and to only accept the data if it was sent within a limited time period. One thing I didn't need, (but I imagine would be necessary in most cases) was to only allow the request once, in which case you would probably want to store the token in a database and flag it once it had been "redeemed."

To create the token, first concatenate current time in epoch seconds (or whatever time format you like, but stick with UTC since the end user may be any where in the world), username, and a password, then m5d and base64 that concatenated string and prepend it with the same timestamp, separated by a colon (':').


#!/usr/bin/ruby
require 'digest/md5'
require 'base64'

# Username/password
UID = 'marypoppins'
PWD = "supercalifragilisticexpialidocious"

# create token using utc secconds, uid, and pwd
def create_token(t=nil)
  timestamp = t || Time.now.utc.to_i.to_s
  plaintext = timestamp + UID + PWD
  md5 = Digest::MD5.digest(plaintext)
  return timestamp + ':' + Base64.encode64(md5).strip
end

# validate token
def validate_token(token)
  token_timestamp = token.split(':')[0]
  token2 = create_token(token_timestamp)
  return token == token2 ? true : false
end

# validate timestamp and token
def validate_token_and_timestamp(token,num_secs=60)
  token_timestamp = token.split(':')[0]
  return nil if Time.now.to_i - token_timestamp.to_i > num_secs
  token2 = create_token(token_timestamp)
  return token == token2 ? true : false
end

The most basic example: create a token and validate it by creating a new token using the timestamp in the original token with the known user id and password. If the two tokens match, the original token is valid (which it will be in this contrived example):


# create a token and validate
if (validate_token(create_token))
  puts "Valid token"
else
  puts "Invalid token"
end

To check if the token was passed within a certain time period, just compare the timestamp on the original token with current time.


# create a token and validate timestamp and token
if (validate_token_and_timestamp(create_token,10))
  puts "Valid token"
else
  puts "Invalid token"
end

For demonstration only, use sleep to timeout a token:


# create a token, but let token timeout before trying to validate
timeout_token = create_token
sleep 15
if (validate_token_and_timestamp(timeout_token,10))
  puts "Valid token"
else
  puts "Invalid token"
end

Self Referential Associations with has_many :through

2008-07-21T14:04:00.000-07:00


db/migrate/001_create_teletubbies.rb

class CreateTeletubbies < ActiveRecord::Migration
  def self.up
    create_table :teletubbies do |t|
      t.string :name
      t.timestamps
    end
    Teletubby.create(:name => 'Tinky Winky')
    Teletubby.create(:name => 'Dipsy')
    Teletubby.create(:name => 'Laa Laa')
    Teletubby.create(:name => 'Po')
  end

  def self.down
    drop_table :teletubbies
  end
end

db/migrate/002_create_friendships.rb

class CreateFriendships < ActiveRecord::Migration
  def self.up
    create_table :friendships do |t|
      t.integer :teletubby_id
      t.integer :friend_id
      t.timestamps
    end
    # Tinky Winky loves all the other Teletubbies very much
    Friendship.create(:teletubby_id => 1, :friend_id => 2)
    Friendship.create(:teletubby_id => 1, :friend_id => 3)
    Friendship.create(:teletubby_id => 1, :friend_id => 4)
    # Dipsy loves all the other Teletubbies very much
    Friendship.create(:teletubby_id => 2, :friend_id => 1)
    Friendship.create(:teletubby_id => 2, :friend_id => 3)
    Friendship.create(:teletubby_id => 2, :friend_id => 4)
    # Laa Laa loves Po very much
    Friendship.create(:teletubby_id => 3, :friend_id => 4)
    # Po loves Laa Laa very much
    Friendship.create(:teletubby_id => 4, :friend_id => 3)
    # Big Hug
  end

  def self.down
    drop_table :friendships
  end
end

app/models/teletubby.rb

class Teletubby < ActiveRecord::Base
  # a teletubby 'has_many' friendships (teletubbies love each other very much)
  has_many :friendships

  # a teletubby 'has_many' friends ':through' friendships relationship
  has_many :friends, :through => :friendships
end

app/models/friendship.rb

class Friendship < ActiveRecord::Base
  # ActiveRecord already knows what a teletubby is (reflection)
  belongs_to :teletubby

  # No actual friendship model, so add :class_name and :foreign_key
  belongs_to :friend, :class_name => "Teletubby", :foreign_key => "friend_id"
end

The database should look a little something like this:


mysql> select * from teletubbies;
+----+-------------+---------------------+---------------------+
| id | name        | created_at          | updated_at          |
+----+-------------+---------------------+---------------------+
|  1 | Tinky Winky | 2008-07-21 15:41:42 | 2008-07-21 15:41:42 | 
|  2 | Dipsy       | 2008-07-21 15:41:42 | 2008-07-21 15:41:42 | 
|  3 | Laa Laa     | 2008-07-21 15:41:42 | 2008-07-21 15:41:42 | 
|  4 | Po          | 2008-07-21 15:41:42 | 2008-07-21 15:41:42 | 
+----+-------------+---------------------+---------------------+
4 rows in set (0.00 sec)

mysql> select * from friendships;
+----+--------------+-----------+---------------------+---------------------+
| id | teletubby_id | friend_id | created_at          | updated_at          |
+----+--------------+-----------+---------------------+---------------------+
|  1 |            1 |         2 | 2008-07-21 15:41:42 | 2008-07-21 15:41:42 | 
|  2 |            1 |         3 | 2008-07-21 15:41:42 | 2008-07-21 15:41:42 | 
|  3 |            1 |         4 | 2008-07-21 15:41:42 | 2008-07-21 15:41:42 | 
|  4 |            2 |         1 | 2008-07-21 15:41:42 | 2008-07-21 15:41:42 | 
|  5 |            2 |         3 | 2008-07-21 15:41:42 | 2008-07-21 15:41:42 | 
|  6 |            2 |         4 | 2008-07-21 15:41:42 | 2008-07-21 15:41:42 | 
|  7 |            3 |         4 | 2008-07-21 15:41:42 | 2008-07-21 15:41:42 | 
|  8 |            4 |         3 | 2008-07-21 15:41:42 | 2008-07-21 15:41:42 | 
+----+--------------+-----------+---------------------+---------------------+
8 rows in set (0.00 sec)

Use script/console to check the relationships:


dsparling-imbps-computer:~/Sites/teletubbies dsparlingimbp$ script/console 
Loading development environment (Rails 2.0.2)
>> t1 = Teletubby.find(1)
=> #<Teletubby id: 1, name: "Tinky Winky", created_at: "2008-07-21 15:41:42", updated_at: "2008-07-21 15:41:42">
>> t1.friends.each { |f| puts "#{t1.name} loves #{f.name} very much." }; false
Tinky Winky loves Dipsy very much.
Tinky Winky loves Laa Laa very much.
Tinky Winky loves Po very much.
=> false
>> t2 = Teletubby.find(2)
=> #<Teletubby id: 2, name: "Dipsy", created_at: "2008-07-21 15:41:42", updated_at: "2008-07-21 15:41:42">
>> t2.friends.each { |f| puts "#{t2.name} loves #{f.name} very much." }; false
Dipsy loves Tinky Winky very much.
Dipsy loves Laa Laa very much.
Dipsy loves Po very much.
=> false
>> t3 = Teletubby.find(3)
=> #<Teletubby id: 3, name: "Laa Laa", created_at: "2008-07-21 15:41:42", updated_at: "2008-07-21 15:41:42">
>> t3.friends.each { |f| puts "#{t3.name} loves #{f.name} very much." }; false
Laa Laa loves Po very much.
=> false
>> t4 = Teletubby.find(4)
=> #<Teletubby id: 4, name: "Po", created_at: "2008-07-21 15:41:42", updated_at: "2008-07-21 15:41:42">
>> t4.friends.each { |f| puts "#{t4.name} loves #{f.name} very much." }; false
Po loves Laa Laa very much.
=> false

Screencast Addiction

2008-07-12T21:02:00.000-07:00

Ruby/RoR
http://www.railsenvy.com/speaking
http://railscasts.com
http://www.rubyplus.org
http://www.buildingwebapps.com/podcasts
http://peepcode.com
http://www.pragprog.com/screencasts
http://envycasts.com

Rails Conf(s)
http://www.railsenvy.com/tags/conferences
http://www.railsenvy.com/2008/6/2/Railsconf-videos
http://blip.tv/search?q=rails+conf&x=0&y=0
http://www.confreaks.com
http://mwrc2008.confreaks.com/
The RubyFringe Videos

OSCON
http://www.railsenvy.com/2008/7/29/oscon-videos
http://blip.tv/search?q=oscon&x=0&y=0

Other
ThoughtWorks IT Matters and ThoughtWorks Talks
http://www.justin.tv/signals37/archive
http://developer.yahoo.com/yui/theater/
http://www.theflexshow.com/blog/
Gooogle search railsconf
Google search oscon
InfoQ Presentations

ruby-mp3info

2008-07-12T06:55:00.000-07:00

I have an old SanDisk mp3 player that I use to listen to music and podcasts. Though it's a rather small card (512M), it's still annoying to have to scroll through my single playlist to get to a specific file.

The SanDisk sorts by the mp3 info title tag, so I wrote a small script that I run on my podcast files before I load them on my player so that they will show up first in the playlist by prepending '01_' to the mp3 title tag (and using the mp3 filename if the title is nil).

First, install the ruby-mp3info gem if you don't have it:


gem install ruby-mp3info

edit_mp3info_title.rb


require 'rubygems'
require "mp3info"

dir = Dir.open('/Users/dsparlingimbp/PODCAST/mp3')
puts "mp3 directory: #{dir.path}"

dir.each do |file|
  next unless /\.mp3$/ =~ file
  puts "mp3: #{file}"

  mp3file = "#{dir.path}/#{file}"

  Mp3Info.open(mp3file) do |mp3|
    puts "original title: #{mp3.tag.title}"
    title = '01_' + (mp3.tag.title || file)
    mp3.tag.title = title
    puts "new title: #{mp3.tag.title}"
  end

end

Podcast Addiction

2008-07-11T14:25:00.000-07:00

It's bad enough that I subscribe to more RSS feeds than I can possibly read in a day, but I've also become addicted to podcasts...many are tech podcasts, but I listen to a wide variety...

From my current iTunes podcasts directory:

Andy Jordan's Tech Diary
Audible Ajax
boagworld
The Bugle
The Christian Science Monitor - News
Digital Media Insider
The Flex Show (podcast and screencast)
FOO Casts
The French Pod Class
Hanselminutes
IT Conversations
L33t Tech News
Learning Rails (now a screencast)
.NET Rocks!
php_abstract
php|architecht
podcasts - Channel 9
Pragmatic Programmers
Radio Allegro
Rails Envy Podcast
Railscasts (screencast)
Rubyology
Ruby on Rails Podcast
StackOverflow
TalkCrunch
The Thirsty Developer
This American Life
Wall Street Journal Tech News Briefings
Wall Street Journal on Small Business
Wall Street Journal's Your Money Matters
The Washington Institute Podcast
The Web 2.0 Show
Web Design TV
WebDevRadio.com

A few others:
French Vibes

And a couple of "top tech podcasts" links:
The top 40 tech podcasts - .net magazine
Top 10 Best Technology Podcasts

Ignore exisiting directory in subverion Rails repo

2008-07-10T08:51:00.000-07:00

I needed to ignore the log directory of an existing Rails app I had checked out:


svn up
svn delete log
svn commit -m 'removed log dir'
mkdir log
svn add --non-recursive log
svn propset svn:ignore "*" log/
svn commit -m "Add log dir, ignore contents"

With a little help from:
http://rails.wincent.com/wiki/Checking_a_new_Rails_application_into_an_existing_Subversion_repository

BDD - Behaviour Driven Development, RSpec, JSSpec

2008-06-21T10:04:00.000-07:00

Behavior Driven Development - Wikipedia, the free encyclopedia

O'Reilly Network -- Behavior Driven Development Using Ruby (Part 1)

O'Reilly Network -- Behavior Driven Development Using Ruby (Part 2)

O'Reilly Network -- Behavior Driven Development Using Ruby (Part 3)

Behavior-driven testing with RSpec

PeepCode - RSpec Screencast Tutorials

JSSpec - Javascript BDD(Behavior Driven Development) framework

JSSpec - Official Homepage

CocoaMySQL - MySQL GUI for Mac OS X

2008-06-03T18:58:00.000-07:00

I had to restore a MySQL database dump to a server at new host with no shell access. The host recommended SQLyog, but I'm working on this project on my Mac, and SQLyog is Windows only.

CocoaMySQL was a quick and easy install and did exactly what I needed.

Of course, on my Mac itself, it was the standard MySQL command:

$ mysql -h localhost -u root myshinynewdb < mydatabasedump.sql

CSS, Firefox - font-family, form intput and textarea

2008-06-01T16:49:00.000-07:00

I'll do my own write up at some point, but ran across this, which solved a problem I was having with FF:

http://cakebaker.42dh.com/2006/02/02/some-css-trouble-with-input-and-textarea-in-firefox/

cache_fu: Conditional action-caching stops after a period of time

2008-05-22T08:52:00.000-07:00

http://groups.google.com/group/acts_as_cached/browse_thread/thread/eff6287664362f66

fragment_cache.rb


module ActsAsCached
  module FragmentCache
    def self.setup!
      class << CACHE
        include Extensions
      end
      
      setup_fragment_cache_cache
      setup_rails_for_memcache_fragments
      setup_rails_for_action_cache_options
    end
    
    # add :ttl option to cache helper and set cache store memcache object
    def self.setup_rails_for_memcache_fragments
      if ::ActionView.const_defined?(:Template)
        # Rails 2.1+
        ::ActionController::Base.cache_store = CACHE
      else
        # Rails < svn r8619
        ::ActionView::Helpers::CacheHelper.class_eval do
          def cache(name = {}, options = nil, &block)
            @controller.cache_erb_fragment(block, name, options)
          end
        end
        ::ActionController::Base.fragment_cache_store = CACHE
      end
    end

    def self.setup_fragment_cache_cache
      Object.const_set(:FragmentCacheCache, Class.new { acts_as_cached :store => CACHE })
    end
    
    # add :ttl option to caches_action on the per action level by passing in a hash instead of an array
    # 
    # Examples:
    #  caches_action :index                                       # will use the default ttl from your memcache.yml, or 25 minutes
    #  caches_action :index => { :ttl => 5.minutes }              # cache index action with 5 minute ttl
    #  caches_action :page, :feed, :index => { :ttl => 2.hours }  # cache index action with 2 hours ttl, all others use default
    #
    def self.setup_rails_for_action_cache_options
      ::ActionController::Caching::Actions::ActionCacheFilter.class_eval do
        # convert all actions into a hash keyed by action named, with a value of a ttl hash (to match other cache APIs)
        def initialize(*actions, &block)
          if [].respond_to?(:extract_options!)
            #edge
            @options = actions.extract_options!
            @actions = actions.inject(@options.except(:cache_path)) do |hsh, action|
              action.is_a?(Hash) ? hsh.merge(action) : hsh.merge(action => { :ttl => nil })
            end
            @options.slice!(:cache_path)
          else
            #1.2.5
            @actions = actions.inject({}) do |hsh, action|
              action.is_a?(Hash) ? hsh.merge(action) : hsh.merge(action => { :ttl => nil })
            end
          end
        end

        # override to skip caching/rendering on evaluated if option
        def before(controller)
          return unless @actions.include?(controller.action_name.intern)

          # maintaining edge and 1.2.x compatibility with this branch
          # Jan Prill - added && false
          #if @options && false
          # DSS - removed false - false causing else to always run - this may be 
          # because Jan was using Rails 1.2...
          if @options
            action_cache_path = ActionController::Caching::Actions::ActionCachePath.new(controller, path_options_for(controller, @options))
          else
            action_cache_path = ActionController::Caching::Actions::ActionCachePath.new(controller)
          end
          
          # should probably be like ActiveRecord::Validations.evaluate_condition.  color me lazy.
          if conditional = @actions[controller.action_name.intern][:if]
            conditional = conditional.respond_to?(:call) ? conditional.call(controller) : controller.send(conditional)
          end
          # Jan Prill - causing caching to stop after a period of time?
          #@actions.delete(controller.action_name.intern) if conditional == false

          # Jan Prill - added if clause
          cache = controller.read_fragment(action_cache_path.path) if conditional != false
          if cache && (conditional || conditional.nil?)
            controller.rendered_action_cache = true
            if method(:set_content_type!).arity == 2
              set_content_type!(controller, action_cache_path.extension)
            else
              set_content_type!(action_cache_path)
            end
            controller.send(:render, :text => cache)
            false
          else
            # 1.2.x compatibility
            # Jan Prill added &&
            controller.action_cache_path = action_cache_path if (controller.respond_to?(:action_cache_path) && conditional != false)
          end
        end
        
        # override to pass along the ttl hash
        def after(controller)
          # Jan Prill - added || controller.action_cache_path.nil? 
          return if !@actions.include?(controller.action_name.intern) || controller.rendered_action_cache || controller.action_cache_path.nil? 
          # 1.2.x compatibility
          path = controller.respond_to?(:action_cache_path) ? controller.action_cache_path.path : ActionController::Caching::Actions::ActionCachePath.path_for(controller)
          controller.write_fragment(path, controller.response.body, action_ttl(controller))
        end

        private
        def action_ttl(controller)
          @actions[controller.action_name.intern]
        end
      end
    end

    module Extensions
      def read(*args)
        return if ActsAsCached.config[:skip_gets]
        FragmentCacheCache.cache_store(:get, args.first)
      end
      
      def write(name, content, options = {}) 
        ttl = (options.is_a?(Hash) ? options[:ttl] : nil) || ActsAsCached.config[:ttl] || 25.minutes
        FragmentCacheCache.cache_store(:set, name, content, ttl)
      end
    end

    module DisabledExtensions
      def read(*args) nil end
      def write(*args) "" end
    end
  end
end

git

2008-05-20T19:59:00.000-07:00

I've been wanting to play with git, so I created repositories for all my jquery plugins at github.com.

http://github.com/dsparling

For now, that would be:

jClock
datemaker
regexpCommon

git documentation:

http://git.or.cz/#documentation
http://www.sourcemage.org/Git_Guide
http://www.gitcasts.com/

ASP.NET - Import and display Excel spreadsheet

2008-05-06T18:30:00.000-07:00

I needed to upload and parse an Excel spreadsheet and display it in a GridView. For the most part, pretty straight forward. I ran into an issue "Could not find installable ISAM" once I added "IMEX=1" to my connection string. This was solved by adding (char)34 as shown in my working example:


string filePath = "~/somedirectory/somespreadsheet.xls";

string strConn = @"Provider=Microsoft.Jet.OLEDB.4.0;"
+ "Data Source=" +  MapPath(filePath) + ";" 
+ "Extended Properties=" + (char)34
+ "Excel 8.0;IMEX=1;" + (char)34;

DataSet dsRecords = new DataSet();
// "Sheet" is name of sheet being opened, must add $ after the name
OleDbDataAdapter da = new OleDbDataAdapter("SELECT * FROM [Sheet1$]", strConn);
      
//da.TableMappings.Add("Table", "ExcelText");
da.Fill(dsRecords);
scheduleGridView.DataSource = dsRecords.Tables[0].DefaultView;
scheduleGridView.DataBind();

As a note, you can also access the spreadsheet directly using the file path:

    
string strConn = @"Provider=Microsoft.Jet.OLEDB.4.0;" 
+ "Data Source=c:/somedirectory/somespreadsheet.xls;" 
+ "Extended Properties=Excel 8.0;";

will_paginate gem

2008-04-26T07:07:00.000-07:00

While upgrading an old project to Rails 2.0.2 (and having trouble getting the will_paginate plugin to install), I discovered that there is a will_paginate gem:

http://mislav.caboo.se/rails/will_paginate-love/

Railscasts - will_paginate

Rails - ActionController::InvalidAuthenticityToken

2008-04-24T20:35:00.000-07:00


ActionController::InvalidAuthenticityToken in User#login

Showing user/login.html.erb where line #2 raised:

No :secret given to the #protect_from_forgery call.  
Set that or use a session store capable of generating its 
own keys (Cookie Session Store).

This happened after I switched from using the file system to a database for storing sessions (after uncommenting the line "config.action_controller.session_store = :active_record_store" in config/environment.rb).

Once you switch to database store, you'll need to comment the "protect_from_forgery" line in app/controllers/application.rb


# See ActionController::RequestForgeryProtection for details
# Uncomment the :secret if you're not using the cookie session store
#protect_from_forgery # :secret => 'b3e36f40312f075ea2697fb85180e312'

Rails 2.0.2 - setup with functional tests

2008-04-24T20:09:00.000-07:00

If you want to use setup with functional tests in Rails 2.0.2, you'll need to rename the setup method to setup_with_fixtures and call super before running your setup code:

  
def setup_with_fixtures
  super
  # Set up code here
end

mod_rails

2008-03-29T05:58:00.000-07:00

Phusion Passenger (a.k.a. mod_rails for Apache) Preview
Riding Rails: mod_rails is on the way

Ruby on Rails - Using External Asset Hosts

2008-03-23T19:18:00.000-07:00

Rails uses the "public" directory on the current host as the default location for static assets (images, CSS, Javascript, etc). Setting up your Rails app to use an external assets server is as simple as adding a single line to a configuration file.

Add the following line to your config/environment.rb file:


ActionController::Base.asset_host = 'http://assets.yourdomain.com'

It's also possible to set a single environment to use an external asset host:

Add the following line to config/environments/production.rb (the most likely spot - this line should already be in this file, but commented out):


config.action_controller.asset_host = 'http://assets.yourdomain.com'

Now this line in my layout


<%= stylesheet_link_tag 'scaffold/base' %>

will translate to http://assets.yourdomain.com/stylesheets/scaffold/base.css

Additional information on setting up multiple asset hosts can be found at:

http://api.rubyonrails.com/classes/ActionView/Helpers/AssetTagHelper.html

Ruby Gem - Highline

2008-03-12T09:23:00.000-07:00

I was looking for a way to prompt a user for input on the console and ran across the RubyGem HighLine. It does a lot more than this, but here's how to capture STDIN from the console:


#!/usr/local/bin/ruby
require 'rubygems'
require 'highline/import'

username = ask("Enter your username:  ") { |q| q.echo = true }
password = ask("Enter your password:  ") { |q| q.echo = "*" }

Here's the output on the console:


$ ruby highline.rb 
Enter your username:  doug
Enter your password:  ******

Get it here:

HighLine

or simply install the gem the normal way:

$ sudo gem install highline

Autotesting Javascript in Rails

2008-03-12T09:22:00.001-07:00

From Dr. Nic's Blog:

Autotesting Javascript in Rails

Installing Ruby without openssl

2008-03-12T09:19:00.001-07:00

When installing Ruby on an old machine, I got this error:


ruby make[1]: *** [ossl_ssl.o] Error 1

Other than installing openssl, which wasn't option, install ruby without openssl:


$ ./configure prefix=/home/doug/bin/ruby --without-openssl

Javascript - insertAfter(), formatCurrency, DOM Scripting

2008-03-10T22:15:00.001-07:00

insertAfter()


function insertAfter(newElement,targetElement) {
    var parent = targetElement.parentNode;
    if (parent.lastChild == targetElement) {
        parent.appendChild(newElement);
    } else {
        parent.insertBefore(newElement,targetElement.nextSibling);
    }
}

formatCurrency()


function formatCurrency(amount) {
    var i = parseFloat(amount);
    if(isNaN(i)) { i = 0.00; }
    var minus = '';
    if(i < 0) { minus = '-'; }
    i = Math.abs(i);
    i = parseInt((i + .005) * 100);
    i = i / 100;
    s = new String(i);
    if(s.indexOf('.') < 0) { s += '.00'; }
    if(s.indexOf('.') == (s.length - 2)) { s += '0'; }
    s = minus + s;
    return s;
}

DOM scripting - create text node with value of  


var textEl = document.createTextNode('\u00a0');

Accordion Effects with Scriptaculous

2008-03-10T12:16:00.000-07:00

I had a couple recent projects that required an accordion effect. I normally use jQuery, but found a couple nice Prototype/Scriptaculous accordions (one is for a Rails project, so we're already using Scriptaculous).

stickman labs
grf-design

Note - The stickman labs accordion doesn't appear to work with the latest Prototype (1.6.1). I'm using the combined js file from the stickman site.

jQuery Sortable with Ajax, PHP, and MySQL

2008-02-27T17:19:00.000-08:00

I needed to create a sortable list that would save the order position of data items. I've been using jQuery more and more and decided to go with the Interface Elements for jQuery.

I found a blog entry titled jQuery Sortable Ajax PHP Integration that was a good start. However, it didn't actually use MySQL to store the sorted data so I've gone ahead and added the database queries and updates.

First I created a simple table to store links (I'd like my client to order the links they enter through an admin interface).


CREATE TABLE links ( 
id int(10) NOT NULL auto_increment, 
link_url varchar(50) NOT NULL, 
link_text varchar(50) NOT NULL, 
order_position int(2), 
primary key(id) 
);

Next is the PHP page that reads the link data from the table and displays the links based on the order_position column of the table.

index.php


<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
                    "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<script type="text/javascript" src="/js/jquery/jquery-1.2.3.min.js"></script>
<script type="text/javascript" src="interface.js"></script>
  
<script>
$(document).ready(
  function() {
    $("#sortme").Sortable({
      accept : 'sortitem',
      onchange : function (sorted) {
        serial = $.SortSerialize('sortme');

        $.ajax({
                  url: "sortdata.php",
                  type: "POST",
                  data: serial.hash,
                  // complete: function(){},
                  //success: function(feedback){ $('#data').html(feedback); }
                  // error: function(){}
        });
      }
    });
  }
);

  </script>
</head>
<body>

<ul id="sortme">
<?php
  // Connect to the database as necessary
  $dbh = mysql_connect('127.0.0.1','username','password')
    or die ("Unaable to connnect to MySQL");

  $selected = mysql_select_db("sort_test",$dbh)
    or die("Could not select sort_test");

  $result = mysql_query('SELECT * FROM links ORDER BY order_position');
  while ($row = mysql_fetch_array($result)) {
    print '<li id="' . $row{'id'} . '" class="sortitem">' . $row{'link_text'} . "\n";
  }
  mysql_close($dbh);
?>
</ul>
 
</body>
</html>

This will make an Ajax call back to the server where PHP will update the database as you drag and sort the list data:

sortdata.php


<?php

$sortme = $_POST['sortme'];
// Connect to the database as necessary
$dbh = mysql_connect('127.0.0.1','username','password')
  or die ("Unaable to connnect to MySQL");

$selected = mysql_select_db("sort_test",$dbh)
  or die("Could not select sort_test");

for ($i = 0; $i < count($sortme); $i++) {
  mysql_query("UPDATE links SET order_position=$i WHERE id=$sortme[$i]");
}
mysql_close($dbh);
?>

A little CSS certainly wouldn't hurt things. Here's some I found on another tutorial:


<style>
ul {
  list-style: none;
}
li {
  background: #727EA3;
  color: #FFF;
  width: 100px;
  margin: 5px;
  font-size: 10px;
  font-family: Arial;
  padding: 3px;
}
</style>

I wouldn't call this production ready code, but all the pieces are in place if you'd like to use jQuery with Ajax, PHP, and MySQL for a sortable list. Don't forget, you'll need to get jQuery itself and the interface.js file as well. Another thing to consider is alerting the user if the update fails or takes a long time.

Ruby on Rails - Testing with Multiple Databases

2008-02-21T12:42:00.000-08:00

I ran into errors when running tests for a Rails app using multiple databases. When testing, fixtures are automatically inserted into the primary database, and I was getting an error on an unused default fixture that was created when I built the model tied to the second database. Removing that fixture got my tests to pass...

More info here:

http://www.elctech.com/2007/3/8/using-and-testing-rails-with-multiple-databases
http://www.elctech.com/2007/5/30/using-and-testing-multiple-databases-in-rails-part-2

and on multiple databases in general:

http://wiki.rubyonrails.org/rails/pages/HowtoUseMultipleDatabases
http://wiki.rubyonrails.org/rails/pages/HowtoUseMultipleDatabasesWithFixtures

jQuery

2008-02-19T17:41:00.000-08:00

I've been using the jQuery Javascript library a lot lately and it's definitely become my favorite library. (I've written four plugins in the last couple months to boot)

Here are a few links to useful jQuery resources.

jQuery: The Write Less, Do More, JavaScript Library
jQuery UI: Widgets, Components, and Interaction
Plugins - jQuery JavaScript Library
jQuery Blog
Learning jQuery
Visual jQuery
IBM developerWorks: Simplify Ajax development with jQuery

composite_primary_keys.gem

2008-02-19T17:35:00.000-08:00

Ruby on Rails does not support composite primary keys and a legacy database I'm working with has lots of them...after a quick search I found this useful Gem:

composite_primary_keys.

Easy Restful Rails Screencast

2008-01-31T18:21:00.000-08:00

http://www.akitaonrails.com/2008/1/25/easy-restful-rails-screencast

10 Ruby on Rails Plugins You Should Be Using

2008-01-23T14:31:00.000-08:00

Media72: 10 Ruby on Rails Plugins You Should Be Using

jQuery: Cookie Plugin

2008-01-23T08:09:00.000-08:00

I've become a big fan of jQuery and have contributed two small plugins myself, so when it came time to switch to a library for cookie manipulation with Javascript (time to replace all that nasty inline JS code) my first choice was jQuery.

Not to be disappointed, I found that Klaus Hartl has written a very slim and useful Cookie Plugin for jQuery.

Here's a small page test using the jQuery Cookie plugin:


<html>
<head>
  <title>jquery cookie</title>

  <script type="text/javascript" src="jquery-1.2.1.min.js"></script>
  <script type="text/javascript" src="jquery.cookie.js"></script>

  <script type="text/javascript">

    $(function($) {

      function displayMessage(msg) {
        $('#message').html(msg).css({color: 'green'});
      }

      displayMessage('jQuery cookie plugin test');

      $('#setSessionCookie').click(function() { 
        $.cookie('test', 'Hmmm, cookie');
        displayMessage("Cookie 'test' has been set.");
      });

      $('#setCookie').click(function() {
        $.cookie('test', 'Hmmm, cookie', { expires: 7 });
        displayMessage("Cookie 'test' has been set and will expire in 7 days.");
      });

      $('#getCookie').click(function() {
        displayMessage("The value of the cookie named 'test' is: " + $.cookie('test'));
      });

      $('#deleteCookie').click(function() {
        $.cookie('test', null);
        displayMessage("Cookie 'test' has been deleted.");
      });

      $('#testCookiesEnabled').click(function() {
        $.cookie('testcookiesenabled', null);
        $.cookie('testcookiesenabled', 'enabled');
        if ($.cookie('testcookiesenabled')) {
          displayMessage("Cookie: "+ $.cookie('testcookiesenabled'));
        } else {
          displayMessage("Cookies disabled");
          $.cookie('testcookiesenabled', null);
        }
      });

    });

  </script>

</head>

<body>

<p><span id="message" style="forecolor: red;"></span>

<p><input type="button" id="testCookiesEnabled" value="Cookies enabled?"/></p>

<p><input type="button" id="setSessionCookie" value="Set session cookie"/></p>

<p><input type="button" id="setCookie" value="Set cookie expires in  7 days"/></p>

<p><input type="button" id="getCookie" value="Show cookie value"/></p>

<p><input type="button" id="deleteCookie" value="Delete the cookie"/></p>

</body>
</html>

My jQuery cookie demo using jquery.cookie.js

ASP.NET GridView - Header always bold

2008-01-21T16:17:00.000-08:00

GridView uses a table and creates a <th> tag for the header, which will bold all the text generated by the GridView. Here's a simple solution:

Set a style:


<style>
.GridViewHeaderStyle th {
  font-weight: normal;  
}
</style>

And apply it to your GridView:


<asp:GridView ID="grdSomeGrid" runat="server" CssClass="GridViewHeaderStyle">
...
</asp:GridView>

ASP.NET GridView "ShowFooter"

2008-01-19T11:06:00.000-08:00

Sometimes it's the small things that get you...

Uh, not that it ever happened to me, but in case you can't get your GridView template footer to show up...don't forget 'ShowFoooter="true"' :)


<asp:GridView ID="grdListings" runat="server" AutoGenerateColumns="false" BorderWidth="0" 
AllowPaging="true" PageSize="5" OnPageIndexChanging="grdListings_PageIndexChanging" ShowFooter="true">
                   
<Columns>
<asp:TemplateField>
                                    
<HeaderTemplate>
Header         
</HeaderTemplate>

<ItemTemplate>
Item
</ItemTemplate>

<FooterTemplate>
Footer
</FooterTemplate>
                                    
</asp:TemplateField>
</Columns>
</asp:GridView>

Install Ruby without openssl

2008-01-05T07:29:00.000-08:00

When installing Ruby on an old machine, I got this error:


ruby make[1]: *** [ossl_ssl.o] Error 1

Other than installing openssl, which wasn't option, install ruby without openssl:


$ ./configure prefix=/home/doug/bin/ruby --without-openssl

Autotesting Javascript in Rails

2008-01-05T07:26:00.000-08:00

From Dr. Nic's Blog:

Autotesting Javascript in Rails

Upgrading to specific version of Rails

2008-01-03T12:20:00.000-08:00


sudo gem install -v=2.0.1 rails --include-dependencies

How to pass variables thru a DataGrid hyperlink column

2007-12-30T17:19:00.000-08:00


<asp:HyperLink NavigateUrl='<%# "SomePage.aspx?someparam=" + DataBinder.Eval(Container, "DataItem.PropertyID") %>' runat="server" />

Ruby Blog

2007-12-19T19:19:00.000-08:00

I've decided to create a Ruby only blog, though I'll keep cross posting here for now...who knows, I may change my mind and just keep the one blog here...

spariamsgems

Viewing .CHM files on Mac OS X - Chmox

2007-12-19T19:09:00.000-08:00

I tried several Mac options and had no luck (xchm froze, libchmxx has a utility called chmdissect - it worked, but no images)...finally, I struck gold with Chmox.

1) Install CHMLIB - http://www.jedrea.com/chmlib/


% ./configure
% make
% sudo make install

2) Install Chmox - http://chmox.sourceforge.net/

The binary is a standard dmg file...click on the dmg file and move the application over to your application directory.

Sending E-mail with Ruby Net::SMTP

2007-12-10T14:21:00.001-08:00

All you need to know is here:
http://www.ruby-doc.org/stdlib/libdoc/net/smtp/rdoc/classes/Net/SMTP.html


def send_email(from, from_alias, to, to_alias, subject, message)

  msg = <<EOF
From: #{from_alias} <#{from}>
To: #{to_alias} <#{to}>
Subject: #{subject}
 
#{message}
EOF

  Net::SMTP.start('localhost') do |smtp|
    smtp.send_message(msg, from, to)
  end
 
end

Or if your mail server is on another machine:


  Net::SMTP.start(mail_server, port, helo_domain) do |smtp|
    smtp.send_message msg, from, to
  end

For example:


smtp.send_message('your.smtp.server', 25, 'mail.from.domain')

ASP.NET Calendar Control - Misc

2007-11-21T11:02:00.000-08:00

How to: Display Selected Dates from a Database in the Calendar Control

Hide days that aren't in current month:


protected void Calendar1_DayRender(object sender, DayRenderEventArgs e)
{
    if (e.Day.Date.Month != Calendar1.VisibleDate.Month)
    e.Cell.Text = "";
}

Disable link for particular day (the 23rd, in this case):


protected void cal_DayRender(object source, DayRenderEventArgs e)
{
    if (e.Day.Date.Day == 23)
    {
        e.Cell.Controls.Clear();
        e.Cell.Text = e.Day.DayNumberText; 
        e.Cell.BackColor = System.Drawing.Color.Gainsboro;
    }
}

ASP.NET HyperLink Control: mailto link

2007-11-20T11:12:00.000-08:00


<asp:HyperLink ID="EmailLink" text='<%# Eval("UserEmail") %>' NavigateUrl='<%# Eval("UserEmail","mailto:{0}")%>' runat="server" target="_blank" />

With a "Subject"


<asp:HyperLink ID="EmailLink" text='<%# Eval("UserEmail") %>' NavigateUrl='<%# Eval("UserEmail","mailto:{0}?Subject=YourQuestion")%>' runat="server" target="_blank" />

Identify Button Clicked in GridView

2007-11-17T09:18:00.000-08:00

I had a GridView with a ButtonField used to Select a record to display a User's details in a DetailsView. I wanted a second button to display different form for changing a Users's password, since I wanted that to be a separate option.

GridView (usersGrid):


<asp:ButtonField CommandName="Select" Text="Select" />
<asp:TemplateField>
    <ItemTemplate>
        <asp:LinkButton runat="server" ID="changePasswordButton" Text="Change Password" OnClick="usersGrid_SelectRow" />
    </ItemTemplate>
</asp:TemplateFild>

Code Behind:


protected void usersGrid_SelectRow(object sender, EventArgs e)
{
    GridViewRow row = (GridViewRow)((LinkButton)sender).Parent.Parent;
    usersGrid.SelectedIndex = row.RowIndex;

    MyDatabase.DBUtil = new MyDatabase.DBUtil();
    changePasswordDetails.DataSource = DB.GetUser(Int16.Parse(usersGrid.SelectedValue.ToString());
    changePasswordDetails.ChangeMode(DetailsViewMode.ReadOnly);
    userDeatils.Visible = false;
    changePasswordDetails.Visible = true;
    changePasswordDetails.DataKeyNames = new string[] { "UserID" };
    changePasswordDetails.DataBind();
}

.NET Smart Delete (Details View Client-side delete confirmation)

2007-11-09T23:11:00.000-08:00

I was working on a database-driven web site and I needed a way to make sure that the admin couldn't delete all the admin user accounts (that was simple enough), but I also wanted a javascript confirmation popup when an admin did delete accounts.

I found exactly what I was looking for on Dino Esposito's WebLog on his post ASP.NET Today: Smart Delete:

DetailsView and FormView controls support delete operations and delegate the execution to the underlying data source control. If the data source control is configured to execute the delete operation, all works fine, otherwise an exception is thrown.

The DetailsView generates command buttons automatically and doesn't expose them directly to page code. How can you add a bit of Javascript code to ask for confirmation? Here's the code.
protected void DetailsView1_ItemCreated(object sender, EventArgs e)
{
   // Test FooterRow to make sure all rows have been created 
   if (DetailsView1.FooterRow != null)
   {
     // The command bar is the last element in the Rows collection
     int commandRowIndex = DetailsView1.Rows.Count-1;
     DetailsViewRow commandRow = DetailsView1.Rows[commandRowIndex];
     
     // Look for the DELETE button
     DataControlFieldCell cell = (DataControlFieldCell) commandRow.Controls[0];
     foreach(Control ctl in cell.Controls)
     {
       LinkButton link = ctl as LinkButton;
       if (link != null)
       {
          if (link.CommandName == "Delete")
          {
             link.ToolTip = "Click here to delete";
             link.OnClientClick = "return confirm('Do you really want to delete this record?');";
          }
       }
    }
}
The ItemCreated event doesn't provide any information about the row being created. However, it can be figured out that the footer row is always created and is always the last row to be created. If the FooterRow object is not null, you can conclude that all rows have been created, including the command bar. The command bar is the first row after the data rows and is stored in the Rows collection--it's the last element in the collection. The command bar is a table row (type is DetailsViewRow) and contains a cell (type is DataControlFieldCell). The cell contains as many link buttons (type is DataControlLinkButton) as there are commands. Delete, Edit, New, Update, Cancel are the command names used and useful to identify the right button.

The FormView is fully templated and lets you manually define appearance and behavior of command buttons. If you place a custom button, or want to use a custom command name for a standard button (Edit, New, Delete), here's how to detect the click on the button. You start by adding a handler for ItemCommand. The code below shows how to deal with a custom Delete button that checks if the bound data source control is enabled for deletion before proceeding.
protected void FormView1_ItemCommand(object sender, FormViewCommandEventArgs e)
{
  if (e.CommandName == "SmartDelete")
  {
    IDataSource obj = (IDataSource) FindControl(FormView1.DataSourceID);
    DataSourceView view = obj.GetView("DefaultView");
    if (!view.CanDelete) {
       Response.Write("Sorry, you can't delete");
       return;
    }
    else 
       FormView1.DeleteItem();
  }
}

Formatting Date Field in Grid View

2007-11-06T17:49:00.000-08:00

Due to a bug fix in .NET 2.0, HtmlEncode must be set to False for date formatting to give expected results:


<asp:BoundField DataField="AgendaDate" HeaderText="Agenda Date" SortExpression="AgendaDate" DataFormatString="{0:yyyy-MM-dd}" HtmlEncode=False />

In a Details View using TemplateFields:


<ItemTemplate>
  <asp:Label ID="agendaDateLabel" runat="server" Text='<%# Eval("AgendaDate", "{0:yyyy-MM-dd}") %>'></asp:Label>
</ItemTemplate>

SQL Server 2005 Check Constraint

2007-11-03T07:39:00.000-07:00

I wanted to use something like the MySQL Enum constraint in SQL Server to limit the values allowed in a column...

I ended up using a separate table and a foreign key for this, but never the less, here's how to use the Check constraint, in my case, to limit RecordStatus to contain only 'Active' or 'Inactive':


CREATE TABLE NewsItems (
  NewsItemID int IDENTITY NOT NULL PRIMARY KEY,
  RecordStatus nvarchar(10) NOT NULL DEFAULT 'ACTIVE' CHECK (RecordStatus IN ('Active', 'Inactive'))
);

ASP .NET - C# Decimal Comparison

2007-10-19T22:28:00.000-07:00

A little more shopping cart hacking. Here's how do to Decimal comparisons in C#:


        public static decimal GetShippingCost()
        {
            decimal sum;
            decimal shippingCost;
            sum = GetSubtotal() - GetCouponDiscount();
            if (sum < 0)
                sum = 0;

            if ( Decimal.Compare(sum, 26.95m) <= 0 )
                shippingCost = 8.95m;
            else if ( Decimal.Compare(sum, 35.95m) <= 0 )
                shippingCost = 11.95m;
            else if ( Decimal.Compare(sum, 45.95m) <= 0 )
                shippingCost = 12.95m;
            else if ( Decimal .Compare(sum, 55.95m) <= 0 )
                shippingCost = 16.95m;
            else if ( Decimal.Compare(sum, 74.95m) <= 0 )
                shippingCost = 18.95m;
            else if ( Decimal.Compare(sum, 99.95m) <= 0 )
                shippingCost = 20.95m;
            else if ( Decimal.Compare(sum, 119.95m) <= 0 )
                shippingCost = 22.95m;
            else if (Decimal.Compare(sum, 139.95m) <= 0 )
                shippingCost = 24.95m;
            else if (Decimal.Compare (sum, 159.95m) <= 0 )
                shippingCost = 26.95m;
            else if (Decimal.Compare(sum, 199.95m) <= 0 )
                shippingCost = 29.95m;
            else if ( Decimal.Compare(sum, 249.95m ) <= 0 )
                shippingCost = 32.95m;
            else if (Decimal.Compare(sum, 299.95m) <= 0 )
                shippingCost = 34.95m;
            else
                shippingCost = 34.95m;

            return shippingCost;
        }

ASP .NET - Redirecting to HTTPS

2007-10-19T22:17:00.000-07:00

On a project where I had to install a third party shopping cart, one issue that came up was to make sure all the pages ran under https (many hard coded links used "http").

I put the following code in the Global.asax file:


protected void Application_BeginRequest(Object sender, EventArgs e)
{
    if (Request.Url.Port != 443)
    {
        Response.Redirect ("https://www.yourdomain.com" +  Request.Url.AbsolutePath, true);
    }
}

This uses


Request.IsSecureConnection

to determine if the call was made over SSL.

So


if (Request.IsSecureConnection)
{
    Response.Write("HTTPS");
}
else
{
    Response.Write("HTTP");
}

Another way to write this:


if (!Request.IsSecureConnection)
{ 
    string serverName =HttpUtility.UrlEncode(Request.ServerVariables["SERVER_NAME"]);        
    string filePath = Request.FilePath;
    Response.Redirect("https://" + serverName + filePath);
}

Classic ASP: Sending e-mail (CDONTS -> CDOSYS)

2007-10-18T13:11:00.000-07:00

One of today's jobs was fixing a mail script running on classic ASP that died after being moved to a new server. Attempting to send an email resulted in this error:


Microsoft VBScript runtime  error '800a01ad'

ActiveX component can't create object: 'CDONTS.Newmail'

/aspmailer.asp, line 45

CDONTS has been deprecated and replaced with CDOSYS.

I updated aspmailer.asp (a somewhat redundantly named script) to use CDOSYS. After the update, I got this error:


The "SendUsing" configuration value is invalid.

So I still need a bit more code.

This site provided the needed fix:

http://classicasp.aspfaq.com/email/how-do-i-send-e-mail-with-cdo.html


<!-- 
    METADATA 
    TYPE="typelib"  
    UUID="CD000000-8B95-11D1-82DB-00C04FB1625D"  
    NAME="CDO for Windows 2000 Library" 
--> 
<%  
    Set cdoConfig = CreateObject("CDO.Configuration")  
 
    With cdoConfig.Fields  
        .Item(cdoSendUsingMethod) = cdoSendUsingPort  
        .Item(cdoSMTPServer) = "<enter_mail.server_here>"  
        .Update  
    End With 
 
    Set cdoMessage = CreateObject("CDO.Message")  
 
    With cdoMessage 
        Set .Configuration = cdoConfig 
        .From = "from@me.com" 
        .To = "to@me.com" 
        .Subject = "Sample CDO Message" 
        .TextBody = "This is a test for CDO.message" 
        .Send 
    End With 
 
    Set cdoMessage = Nothing  
    Set cdoConfig = Nothing  
%>

Replace <enter_mail.server_here> with the name or IP of your SMTP mail server ("localhost" may do the trick).

The other example provided is as follows:


<% 
    sch = "http://schemas.microsoft.com/cdo/configuration/" 
 
    Set cdoConfig = CreateObject("CDO.Configuration") 
 
    With cdoConfig.Fields 
        .Item(sch & "sendusing") = 2 ' cdoSendUsingPort 
        .Item(sch & "smtpserver") = "<enter_mail.server_here>" 
        .update 
    End With 
 
    Set cdoMessage = CreateObject("CDO.Message") 
 
    With cdoMessage 
        Set .Configuration = cdoConfig 
        .From = "from@me.com" 
        .To = "to@me.com" 
        .Subject = "Sample CDO Message" 
        .TextBody = "This is a test for CDO.message" 
        .Send 
    End With 
 
    Set cdoMessage = Nothing 
    Set cdoConfig = Nothing 
%>

JavaScript Style

2007-09-26T07:02:00.000-07:00

As I've been doing a lot of Javascript and Ajax these days, I've found these resources valuable:

JavaScript style and the art of anal retention

Dojo style guide
Ajaxian commentary on Dojo style guide
Crockford style guide, part 1
Crockford style guide, part 2
Ajaxian commentary on Crockford style guide
Mozilla style guide

Ruby on Rails - Legacy MySQL Database

2007-09-19T14:37:00.000-07:00

I'm rewriting a company admin tool written in mod_perl (Catalyst) and replacing it with a new one using Ruby on Rails. At the moment, I have to keep the legacy database/schema. Most of the old tables don't use auto-incrementing keys, which means I won't get the Rails Active::Record magic and I need to work around the keys.

Here's an example table:

mysql> describe clients;
+--------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+--------------+-------------+------+-----+---------+-------+
| client_abbrv | varchar(5) | NO | PRI | | |
| client_name | varchar(50) | YES | | NULL | |
+--------------+-------------+------+-----+---------+-------+

To get this to work with Rails, I had to make a few small changes.

I made one small change in the view, which was setting the name of the primary key field. I changed "client_abbrv" to "id" in the form:

app/views/client/new.rhtml


<%= error_messages_for 'client' %>

  <fieldset>
    <legend>Add a Client
    <% form_tag :action => "create" do %>
      <p>
        <label for="client_client_name">Client Name:
        <%= text_field 'client', 'client_name'  %>
      </p>
      <p>
        <label for="client_id">Client Abbrv:
        <%= text_field 'client', 'id' %>
      </p>
      <p>
      <%= submit_tag 'Add' %>
      </p>
    <% end %>
  </fieldset>

For the model, I had set the primary key with set_primary_key.

app/models/clients.rb


class Client < ActiveRecord::Base
set_primary_key "client_abbrv"
end

Luckily, the table was already pluralized. If it had been "client," then I would have had to add this line:


def self.table_name() "client" end

For the controller, I had to change the create method:

app/controllers/client_controller.rb


def create
  @client = Client.new
  @client.id = params[:client][:id]
  @client.client_name = params[:client][:client_name]
  if @client.save
    flash[:notice] = "Client was successfully created."
    redirect_to :action => 'list'
  else
    render :action => 'new'
  end
end

That replaced the old create method where I had the normal:


@client = Client.new(params[:client])

When using set_primary_key, you insert data using "id" and typically select data using the actual field name, "client_abbrv" in this case.

Here's what the controller is doing for the create method:


dsparling-imbps-computer:~/my/rubydev/uclick-admin dsparlingimbp$ script/console 
Loading development environment.
>> client = Client.new
=> #<Client:0x32b5e14 @new_record=true, @attributes={"client_name"=>nil}>
>> client.id = "abc"
=> "abc"
>> client.client_name = "ABC Company"
=> "ABC Company"
>> client.valid?
=> true
>> client.save
=> true

Javascript Resources

2007-09-08T09:18:00.001-07:00

Yahoo! UI Library: YUI Theater
Douglas Crockford — "The JavaScript Programming Language"
Douglas Crockford — "An Inconvenient API: The Theory of the DOM"
Douglas Crockford — "Advanced JavaScript"

Douglas Crockford
Douglas Crockford's Javascript
Code Conventions for the JavaScript Programming Language

John Resig
John Resig
John Resig - JavaScript Talk at Northeastern (video)

Misc
QuirksMode - JavaScript
netscape devedge: JavaScript Central
webdeveloper.com: JavaScript
Web Reference JavaScript
W3Schools JavaScript
Tutorial
DHTML Goodies
JavaScript Toolbox
JavaScript Toolbox
JavaScript Toolbox - Best Practices
comp.lang.javascript FAQ

Tools
JSLint, The JavaScript Verifier
JSMIN, The JavaScript Minifier
dean.edwards.name/packer/
JsUnit

W3C
W3C Document Object Model

Books
JavaScript: The Definitive Guide by David Flanagan
Pro Javascript Techniques by John Resig
JavaScript: The Good Part by Douglas Crockford
Learning jQuery by Karl Swedberg and Jonathan Chaffer

Upgrading to PHP5 on Mac OS X 10.4

2007-09-01T23:16:00.000-07:00

I've been running PHP5 for ages on my Linux box, but my new (for me) MacBook Pro had PHP4...um, time for an upgrade. Well, easy enough...

I downloaded the PHP5 tarball from http://www.entropy.ch/software/macosx/php/ and did the install.

Before the install, I commented out all the php4 lines in my apache config file(/etc/httpd/httpd.conf).

The entropy package installed under /usr/local/php5 and it added a new config file (/private/etc/httpd/users/+entropy-php.conf), which is included by the main apache httpd.conf file...restart apache, that's it!

RMagick on Mac OSX

2007-08-28T11:27:00.000-07:00

When installing RMagick, I found that X11 hadn't been installed. It's on the developer CD, which I didn't have handy, so here's what I did.

1) read the notes here:

http://developer.apple.com/opensource/tools/runningx11.html

2) Downloaded and installed Xcode and X11SDK from Apple Developers Center.

3) I still needed X11.app, so I downloaded and installed that from:

http://xanana.ucsc.edu/xtal/x11.html

4) Downloaded and installed rm_install from:

http://rubyforge.org/projects/rmagick/

This will install ImageMagick and RMagick with all dependencies.

I originally had downloaded ImageMagick binary and got this error when trying to install RMagick gem:

"Can't install RMagick. Can't find libMagick or one of the dependent libraries. Check the config.log file for more detailed information."

Info on the error here:

http://rubyforge.org/forum/message.php?msg_id=4066

Ruby on Rails - script/console

2007-08-05T14:39:00.000-07:00

A nice and easy way to check you validation rules...

With a table called users with fields user_name, password, and email, we can add simple validation to the model User.


validates_uniqueness_of :user_name, :email
validates_length_of :user_name, :within => 4..20
validates_length_of :password, :within => 4..20
validates_length_of :email, :maximum => 50
validates_format_of :user_name,
                    :with => /^[A-Z0-9_]*$/i,
                    :message => "must contain only letters, " +
                                      "numbers and underscores"
validates_format_of :email,
                    :with => /@/,
                    :message => "must be a valid email address"

Then using script/console, we can check our validation:

First, try to add a bad record:


$ script/console
Loading development environment.
>> user = User.new(:user_name => "pooh bear",
?> :password => "pb",
?> :email => "poohbear_at_100akerwood.com")
=> #"pooh bear", "password"=>"pb", "email"=>"poohbear_at_100akerwood.com"}>
>> user.save
=> false

Then you can inspect the errors individually with errors.on method:


>> user.errors.on(:user_name)
=> "must contain only letters, numbers and underscores"
>> user.errors.on(:password)
=> "is too short (minimum is 4 characters)"
>> user.errors.on(:email)
=> "must be a valid email address"

or all at once with errors.full_messages method:


>> user.errors.full_messages
=> ["Screen name must contain only letters, numbers and underscores", "Password is too short (minimum is 4 characters)", "Email must be a valid email address"]
>>

PHP PEAR: MDB2

2007-07-16T13:25:00.000-07:00

The PEAR DB class has been deprecated and replaced with MDB2.

MDB2 doesn't come with the MySQL driver out to the box, so you need to install that separately:


$ pear install MDB2
$ pear install MDB2_Driver_mysql

Here's a simple select, using the default fetchmode of MDB2_FETCHMODE_ORDERED.


<?
require_once "MDB2.php";

$dsn = 'mysql://my_username:@my_password@127.0.0.1/my_db';

$options = array(
    'debug' => 2,
    'result_buffering' => false,
);

$mdb2 =& MDB2::factory($dsn, $options);
if (PEAR::isError($mdb2)) {
    die($mdb2->getMessage());
}

// Proceed with a query...
$res =& $mdb2->query('SELECT * FROM my_table');

// Always check that result is not an error
if (PEAR::isError($res)) {
    die($res->getMessage());
}

// Iterate through result set (assume default fetchmod is MDB2_FETCHMODE_ORDERED)
while (($row = $res->fetchRow())) {
    echo $row[0] . " " . $row[1] . "<br/>\n";
}

?>

The three possible fetchmode values are:
1) MDB2_FETCHMODE_ORDERED (query results returned as array - column numbers are keys)
2) MDB2_FETCHMODE_ASSOC (query results returned as hash/associative array - column names are keys)
3) MDB2_FETCHMODE_OBJECT (query results returned as object - column names as properties)

To change the default fetchmode and use MDB2_FETCHMODE_ASSOC instead, use the setFetchMode method:


$mdb2->setFetchMode(MDB2_FETCHMODE_ASSOC);

and then iterate through the results:


while ($row = $res->fetchRow()) {
    echo $row['column_name_a'] . ' ' . $row['column_name_b'] . "<br/>\n";
}

Or you can change it per call:


while ($row = $res->fetchRow(MDB2_FETCHMODE_ASSOC)) {
    echo $row['client_abbrv'] . ' ' . $row['client_name'] . "<br/>\n";
}

Here's an example of the first method:


<?
require_once "MDB2.php";

$dsn = 'mysql://my_username:@my_password@127.0.0.1/my_db';

$options = array(
    'debug' => 2,
    'result_buffering' => false,
);

$mdb2 =& MDB2::factory($dsn, $options);
if (PEAR::isError($mdb2)) {
    die($mdb2->getMessage());
}

// Set the fetchmode
$mdb2->setFetchMode(MDB2_FETCHMODE_ASSOC);

// Proceed with a query...
$res =& $mdb2->query('SELECT * FROM my_table');

// Always check that result is not an error
if (PEAR::isError($res)) {
    die($res->getMessage());
}

// Iterate through result set
while ($row = $res->fetchRow()) {
    echo $row['column_name_a'] . ' ' . $row['column_name_b'] . "<br/>\n";
}

?>

You can insert data with a prepared statement:


<?
require_once "MDB2.php";

$dsn = 'mysql://my_username:@my_password@127.0.0.1/my_db';

$options = array(
    'debug' => 2,
    'result_buffering' => false,
);

$mdb2 =& MDB2::factory($dsn, $options);
if (PEAR::isError($mdb2)) {
    die($mdb2->getMessage());
}

// Insert
$statement = $mdb2->prepare('INSERT INTO clients VALUES (?, ?)');
$data = array($var1, $var2);
$statement->execute($data);
$statement->free();
?>

These are just the basics...read all the goodness here:

http://pear.php.net/manual/en/package.database.mdb2.php

PHP PEAR: MDB2 Error: connect failed (localhost MySQL)

2007-07-14T15:19:00.000-07:00

I ran into a persistent connect error when trying to connect to localhost MySQL database with MDB2.

Instead of:

dsn: mysql://my_username:my_password@localhost/my_db

use:

dsn: mysql://my_username:my_password@127.0.0.1/my_db

Viewing Ruby Gem documentation

2007-07-05T12:50:00.000-07:00

1) Command line

$ ri <gem_name>

2) Browser (http://localhost:8808)

$ gem_server

Emulate PHP5 str_split() in PHP4

2007-07-05T12:20:00.000-07:00

/* emulate the php5 str_split function
* array str_split( string $string [, int $split_length])
* Converts a string to an array
* If the optional split_length param is specified, the returned array
* will be broken down into chunks with each being split_length in
* length, otherwise each chuck will be one character in length.
* False is returned if split_length is less than 1. If the split_length
* length exceeds the length of string, the entire string is returned
* as the first (and only) array element.
*/

If you want to use optional split_length:


function str_split($str, $l=1) {
  $str_array = explode("\r\n", chunk_split($str,$l));
  return $str_array;
}

Or optionally, if you just need the simple split (split_length=1):


function str_split($str) {
  $str_array=array();
  $len=strlen($str);
  for($i=0; $i<$len; $i++) {
    $str_array[]=$str{$i};
  }
  return $str_array;
}

Gem List

2007-07-05T09:43:00.000-07:00

Here's a command to list all your installed Gems:


gem list | grep '^[a-zA-Z]'

Eclipse Tutorials

2007-06-12T14:34:00.000-07:00

eclipse-tutorial: Project Home Page
Eclipse Tutorial
developerWorks : Open source : Technical library

APT Quick Reference

2007-06-08T12:25:00.000-07:00

I found this handy apt-get Phil's APT Quick Reference...

Download and install package:

apt-get install package

Update apt's list of available packages:

apt-get update

Upgrade all installed packages with upgrades available:

apt-get upgrade

Upgrade to new distro, or in general upgrade anything available for update including core system packages:

apt-get dist-upgrade

Uninstall package:

apt-get remove package

Uninstall package, and its config files, and don't leave it in the database as 'uninstalled':

apt-get --purge remove package

Search for a package like pattern:

apt-cache search pattern

Get information on installed package:

dpkg -s package

Find which installed package file belongs to:

dpkg -S inetd.conf

List which files are in package:

apt-file list package

Find out what packages provide file:

apt-file search file

Run a command (such as ./configure or make) and have all necessary packages installed as needed:

auto-apt run command

Unless specified, the package in reference doesn't have to be already installed for these to work... but the database needs to be updated. You can update the appropriate database via:

apt-get update

or

auto-apt update

or

apt-file update

Ruby on Rails/Mongrel/Ubuntu

2007-06-08T11:59:00.000-07:00

I've been using Ubuntu lately and decided to install Ruby on Rails and Mongrel.


$ sudo apt-get install ruby irb rdoc

Or download the source for the latest version (apt-get installs 1.8.4, but the latest source is 1.8.6):


$ tar zxvf ruby-1.8.6.tar.gz
$ cd ruby-1.8.6
$ ./configure 
$ make
$ sudo make install

Once ruby is installed, I typically use Gems if I can.

Download the latest Gems at http://rubyforge.org/frs/?group_id=126 (0.9.4 in this case) and then:


$ tar xzvf rubygems-0.9.4.tgz
$ cd rubygems-0.9.4
$ sudo ruby setup.rb

Install Rails:


sudo gem install rails --include-dependencies

Install Mongrel and Mongrel cluster gem plugin:


sudo gem install mongrel --include-dependencies
sudo gem install mongrel_cluster

Install Apache 2.2


$ tar zxvf httpd-2.2.4.tar.gz
$ cd httpd-2.2.4
$ ./configure \
  --prefix=/usr/local/apache \
  --enable-rewrite \
  --enable-headers \
  --enable-ssl \  
  --enable-proxy \ 
  --with-mpm=prefork
$ make
$ sudo make install

I got this error when running configure:


Configuring Apache Portable Runtime Utility library...

checking for APR-util... yes
configure: error: Cannot use an external APR-util with the bundled APR
make: *** [apache] Error 1

Adding this option fixed the problem:


--with-included-apr

Running Apache with a single Mongrel Instance


$ mongrel_rails start -p 8000 -e production -d

Add to apache conf (httpd.connf)


ServerName hostname.com
ServerAlias www.hostname.com

ProxyPass / http://www.hostname.com:8000/
ProxyPassReverse / http://www.hostname.com:8000/
ProxyPreserveHost on

Restart Apache and it will forward requests for www.hostname.com on port 80 to Mongrel server running on port 8000.

Javascript/Ajax Libraries

2007-06-07T08:44:00.000-07:00

I've been working on a few Ajax and DOM scripting projects at work using prototype.js and scriptaculous. Now we're looking at a "Web 2.0" upgrade for some of our sites, so I'm looking at several libraries:

Prototype JavaScript Framework
script.aculo.us
The Dojo Toolkit
Rico
Yahoo! UI Library (YUI)
mootools framework
MochiKit
JQuery

There are many, many more...
OSA Foundation - Survey of Ajax/JavaScript Libraries

Here's an accoridion demo I created with Rico:
My Rico Accordion Demo

DocBook

2007-06-04T22:51:00.002-07:00

I've been tackling some documentation at work and decided to take a look at docbook.

There are a few good resources to start with:

DocBook.org the home of "DocBook: The Definitive Guide" by Norman Walsh and Leonard Muellner (published by O'Reilly & Associates, Inc.), the official documentation for DocBook.

"DocBook XSL: The Complete Guide" by Bob Stayton.

Single-Source Publishing with DocBook XML by Dan York.

With DocBook, you can use SGML (Dsssl styesheets) or XML (XSL stylesheets). I've chosen to work with XML. "DocBook XSL" provides the details of all the tools that are needed. At the moment I'm working on a Mac laptop, using the following:

DocBook DTD: The DTDs can be found at http://www.oasis-open.org/docbook/xml/. I downloaded
version 4.5 (docbook-xml-4.5.zip).

DocBook XSL Stylesheets: The XSL stylesheets can be downloaded from http://sourceforge.net/project/showfiles.php?group_id=21935. I downloaded docbook-xsl 1.72.0.

XSL processor: xsltproc (already installed on my system). There are a few others as well (Saxon, Xalan).

I installed everything in my home directory and worked from there, but LSB proposal is:

DTD: /usr/share/sgml/docbook/xml-dtd-4.5

XSL: /usr/share/sgml/docbook/docbook-xsl-1.72.0/

Create a DocBook XML file (book.xml, for example)


<?xml version="1.0"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5/EN"
"/path/to/dtd/docbook-xml-4.5/docbookx.dtd">
<book>
<bookinfo>
<title>My Book Title</title>
</bookinfo>

<chapter>
<title>Chapter Name</title>

<para>Some text</para>
</chapter>
</book>

Procss to generate html:


$ xsltproc --output book.html /path/to/docbook-xsl-1.72.0/html/docbook.xsl book.xml

You can validate XML using xmllint (parser won't necessarily do it).


$ xmllint --noout book.xml

No output will be seen unless there is an error.

I haven't covered other formats (like converting to pdf using FOP), Java parsers, catalogs, makefiles, and Ant.

Speaking of Ant, here's a resource for DocBook and Ant:

DocBook and Ant.

I've already started looking at using Cocoon with DocBook, but that will be material for another post...

WebSphere Application Server V6.1 on Linux

2007-06-04T22:40:00.000-07:00

I recently downloaded the full-featured trial download of WebSphere Application Server V6.1 to my old Fedora Core 5 laptop.

The installation was amazingly easy...


$ tar zxvf websphere.tar.gz
$ cd WAS/install
$ java -jar WAS/setup.jar
$ cd /opt/IBM/WebSphere/AppServer/bin
$ ./startServer server1

After starting WebSphere, you can check out the sample application:


http://localhost:9080/WSsamples

Audio file conversion

2007-05-25T13:10:00.000-07:00

Here's a collection of small scripts for converting audio file formats using lame, mpg123, and mplayer.

wav2mp3.pl


#!/usr/bin/perl
use strict;
use warnings;

my $in = "/home/doug/music/somedir/";
my $out = $in;

opendir DH_IN, $in || die "Can't open $in: $!";
foreach my $name (sort readdir(DH_IN)) {
  next unless $name =~ /\.wav$/;
  print "NAME: $name\n";
  my($base_name) = ($name =~ /^(.*)\.wav$/);
  my $in_file = "${in}$base_name.wav";
  my $out_file = "${out}$base_name.mp3";
  `lame -b 192 $in_file $out_file`;
}
close DH_IN;

wav2mp3.sh


#!/bin/sh
bitrate="192"
for wavfile in *.wav
do
   echo "input: $wavfile"
   mp3file=`echo $wavfile | sed s/\\.wav/.mp3/`
   echo "output: $mp3file"
   lame -b $bitrate $wavfile $mp3file
done

mp32wav.sh


#!/bin/sh
for mp3file in *.mp3
do
   echo "input: $mp3file"
   wavfile=`echo $mp3file | sed s/\\.mp3/.wav/`
   echo "output: $wavfile"
   mpg123 -w $wavfile $mp3file
done

wma2mp3.sh


#!/bin/sh

if [ -z "$1" ]
then
        echo "Usage: wma2mp3 "
        exit 1
fi

name=`echo $1 | tr ' ' '_' | tr '[A-Z]' '[a-z]'`

name="`basename "$name" .wma`.mp3"

cp "$1" $name

mplayer -vo null -vc dummy -af resample=44100 -ao pcm:waveheader $name && lame -m s -h --vbr-new audiodump.wav -o $name

m4a2mp3.sh


#!/bin/sh

MPLAYER=mplayer
LAME=lame

for m4a in *.m4a
do

    mp3=`echo "$m4a" | sed -e 's/m4a$/mp3/'`
    wav="$m4a.wav"

    if [ ! -e "$mp3" ]; then
        [ -e "$wav" ] && rm "$wav"
   mkfifo "$wav" || exit 255
        mplayer "$m4a" -ao pcm:file="$wav" &>/dev/null &
        lame "$wav" "$mp3"
        [ -e "$wav" ] && rm "$wav"
    fi
done

Finding installed Perl modules

2007-05-25T12:54:00.000-07:00

I don't recall where I came across this little script, but it's quite handy for finding installed Perl modules along with their versions.


#!/usr/bin/perl
use strict;

use ExtUtils::Installed;
my $instmod = ExtUtils::Installed->new();
foreach my $module ($instmod->modules()) {
    my $version = $instmod->version($module) || "???";
    print "$module -- $version\n";
}

iBATIS - part 1

2007-05-16T12:30:00.000-07:00

Very basic and simple iBATIS tutorial for a simple SELECT:

Download iBATIS from http://ibatis.apache.org/

Unpack the tar ball and install the jar file (it's now a single file - something like ibatis-2.3.0.677.jar) somewhere on your classpath...or if using with Tomcat or another servlet container, add it to "/WEB-INF/lib" in your for the webapp.

Database (MySQL)


mysql> describe book;
+------------+--------------+------+-----+---------+----------------+
| Field      | Type         | Null | Key | Default | Extra          |
+------------+--------------+------+-----+---------+----------------+
| id         | int(11)      | NO   | PRI | NULL    | auto_increment |
| title      | varchar(50)  | NO   |     |         |                |
| authors    | varchar(50)  | YES  |     | NULL    |                |
| editor     | varchar(50)  | YES  |     | NULL    |                |
| chapters   | text         | YES  |     | NULL    |                |
| page_count | int(11)      | YES  |     | NULL    |                |
| status     | char(1)      | NO   |     | P       |                |
| price      | decimal(5,2) | YES  |     | NULL    |                |
+------------+--------------+------+-----+---------+----------------+

mysql> SELECT * FROM book;
+----+----------------------+---------+--------+----------+------------+--------+-------+
| id | title                | authors | editor | chapters | page_count | status | price |
+----+----------------------+---------+--------+----------+------------+--------+-------+
|  1 | Learning Perl 3rd Ed | NULL    | NULL   | NULL     |       NULL | P      | 29.99 |
|  2 | Learning Java 4th Ed | NULL    | NULL   | NULL     |       NULL | P      | 29.99 |
+----+----------------------+---------+--------+----------+------------+--------+-------+

SqlMapConfig.xml


PUBLIC "-//iBATIS.com//DTD SQL Map Config 2.0//EN"
"http://www.ibatis.com/dtd/sql-map-config-2.dtd">
<sqlMapConfig>

        <!-- These settings control SqlMap configuration details -->
        <settings
                useStatementNamespaces="true"
        />

        <transactionManager type="JDBC">
                <dataSource type="SIMPLE">
                        <property name="JDBC.Driver" value="com.mysql.jdbc.Driver"/>
                        <property name="JDBC.ConnectionURL" value="jdbc:mysql://localhost/bookdb"/>
                        <property name="JDBC.Username" value="yourusername"/>
                        <property name="JDBC.Password" value="yourpassword"/>
                </dataSource>
        </transactionManager>

        <!-- Identify all SQL Map XML files to be loaded by this SQL map -->
        <sqlMap resource="BookMap.xml" />

</sqlMapConfig>

BookMap.xml


<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE sqlMap
PUBLIC "-//iBATIS.com//DTD SQL Map 2.0//EN"
"http://www.ibatis.com/dtd/sql-map-2.dtd">
<sqlMap namespace="Book">

<resultMap id="get-Result" class="Book">
        <result property="id" column="id"/>
        <result property="title" column="title"/>
</resultMap>

<select id="getById" parameterClass="string" resultMap="get-Result">
SELECT * FROM book WHERE (id = #value#)
</select>

<select id="getAll" parameterClass="string" resultMap="get-Result">
SELECT * FROM book WHERE (status = 'P') ORDER BY title
</select>

</sqlMap>

Book.java


import com.ibatis.sqlmap.client.SqlMapClient;
import java.sql.Date;

public class Book {

  public int getId()
  {
    return id;
  }

  public void setId(int id)
  {
    this.id = id;
  }

  public String getTitle()
  {
    return title;
  }

  public void setTitle(String title)
  {
    this.title = title;
  }

  public char getStatus()
  {
    return status;
  }

  public void setStatus(char status)
  {
    this.status = status;
  }

  private Integer id;
  private String title;
  private char status;
}

BookTest.java


import com.ibatis.sqlmap.client.*;
import com.ibatis.common.resources.Resources;

import java.io.Reader;
import java.util.List;
import java.util.Iterator;

public class BookTest {
  public static void main(String arg[]) throws Exception {
    String resource = "SqlMapConfig.xml";
    Reader reader = Resources.getResourceAsReader(resource);
    SqlMapClient sqlMap = SqlMapClientBuilder.buildSqlMapClient(reader);
    List bookList = sqlMap.queryForList("Book.getAll",null);
    System.out.println("Selected " + bookList.size() + " records.");

    if(bookList.size() == 0){
      System.out.println("OOOPS - bookList size is 0\n");
    }
    Iterator books = bookList.iterator();
    StringBuffer bookBuffer = new StringBuffer();
    while(books.hasNext()){
      Book bookX = (Book)books.next();
      bookBuffer.append("ID: " + bookX.getId() + " TITLE: " + bookX.getTitle() + "\n");
    }
    String bookOptions = bookBuffer.toString();
    System.out.println(bookOptions);
  }
}


$ java BookTest
Selected 2 records.
ID: 2 TITLE: Learning Java 4th Ed
ID: 1 TITLE: Learning Perl 3rd Ed

Tomcat - How to run stand alone on port 80

2007-05-13T12:13:00.000-07:00

With Apache, all ports below 1024 are privileged ports, so normally to run Tomcat as a stand alone server, you'd have to run as root, which is a Very Bad Idea. Using the jsvc interface, it is possible to bind Tomcat to a privileged port, such as port 80.

First, change server.xml to use port 80:


$ cd $CATALINA_HOME/conf
$ sudo vi server.xml

and make this change:


    <!--<Connector port="8080" protocol="HTTP/1.1" -->
    <Connector port="80" protocol="HTTP/1.1"

With Tomcat 5 & 6, there will be a jsvc.tar.gz file in the bin directory of your $CATALINA_HOME directory.


$ cd $CATALINA_HOME/bin
$ sudo tar zxvf jsvc.tar.gz
$ cd jsvc-src
$ sudo autoconf
$ sudo ./configure
$ sudo make
$ sudo cp jsvc ..

I had to add a few packages on Ubuntu to compile jsvc...


$ sudo apt-get install libc6-dev g++ gcc
$ sudo apt-get install make
$ sudo apt-get install autoconf

You can start Tomcat as "tomcat" user (use which ever existing non-privileged user you want, or create a new user):


$ cd $CATALINA_HOME
$ sudo ./bin/jsvc -cp ./bin/bootstrap.jar \
  -user tomcat \
  -outfile ./logs/catalina.out \
  -errfile ./logs/catalina.err \
  org.apache.catalina.startup.Bootstrap

There is a sample starup script in the $CATALINA_HOME/bin/jsvc-src/native directory, which can be modified to work on your system:


$ cd /etc/init.d
$ sudo cp tomcat tomcat.bak (if needed, and make sure it will start on the run levels you need for startup on server boot)
$ sudo cp $CATALINA_HOME/bin/jsvc-src/native/Tomcat5.sh ./tomcat
$ sudo vi tomcat (edit for your system)

Now you can start Tomcat:


$ sudo /etc/init.d/tomcat start

More info can be found at Apache Jakarta Project - commons daemon (Java Service)

Hibernate 3 Tutorial

2007-04-29T22:49:00.000-07:00

Here's a simple Hibernate tutorial which will guide you through installation, configuration, and use of Hibernate 3.2, HSQLDB, Ant, and Java on Linux...

This is a rather contrived example and nothing you would see in the real world, but I'll probably expand on this example in later posts.

You'll need the following to run this Hibernate example:

Apache Ant
Hibernate
Hibernate Tools
Hsqldb

As of April 23, 2007, these were the latest downloads:

apache-ant-1.7.0-bin.tar.gz
hibernate-3.2.2.ga.tar.gz
HibernateTools-3.2.0.beta9a.zip
hsqldb_1_8_0_7.zip

I installed these under /usr/local on my laptop (Fedora), but you can install them anywhere that works for you.

So I ended up with this directory structure:

/usr/local/apache-ant-1.7.0
/usr/local/hibernate-3.2
/usr/local/HibernateTools
/usr/local/hsqldb

Note: Manually create the HibernateTools directory and unzip the HibernateTools zip file there.

Create a project directory where you'll place your project files. I created a project directory called "Book" in my home directory (/home/doug/Book).

Here's the project file layout:


Book -
  build.properties
  build.xml
  classes -
  data -
  src -
    hibernate.cfg.xml  
    log4j.properties
    com - 
      dougsparling -
        AddBook.java  
        Book.hbm.xml  
        Book.java  
        ListBooks.java

Database files will build under the data directory. The classes directory will be created during the Ant build process, so you don't need to create that directory manually.

1) Ant build script

Includes targets to create schema/database tables, prepare project files and directories, and compile java source code, as well as a target to add books to the database and another target to read books from databasae.

Book/build.xml
-------------------


<?xml version="1.0"?>
<project name="book">

  <!-- properties -->
  <property file="build.properties"/>

  <property name="src" value="src"/>
  <property name="class" value="classes"/>
  <property name="data" value="data"/>
  <property name="hibernate.tools"
            value="${hibernate.tools.home}${hibernate.tools.path}"/>

  <!-- project classpath -->
  <path id="project.classpath">
    <pathelement location="${src}"/>
    <pathelement location="${class}"/>
    <pathelement location="${hibernate.home}/hibernate3.jar"/>
    <fileset dir="${hibernate.home}/lib" includes="**/*.jar"/>
    <pathelement location="${hsql.home}/lib/hsqldb.jar"/>
  </path>

  <!-- Hibernate tools classpath -->
  <path id="tools.classpath">
    <path refid="project.classpath"/>
    <pathelement location="${hibernate.tools}/hibernate-tools.jar"/>
  </path>

  <!-- task def for Hibernate Tools -->
  <taskdef name="htools"
           classname="org.hibernate.tool.ant.HibernateToolTask"
           classpathref="tools.classpath"/>

  <!-- Create runtime subdirectories -->
  <target name="prepare">
    <mkdir dir="${class}"/>

    <!-- Copy property files and O/R mappings needed at runtime -->
    <copy todir="${class}">
      <fileset dir="${src}">
        <include name="**/*.properties"/>
        <include name="**/*.cfg.xml"/>
      </fileset>
    </copy>
  </target>

  <!-- Generate schemas for all mapping files -->
  <target name="schema" depends="prepare">
    <htools destdir="${data}">
      <classpath refid="tools.classpath"/>
      <configuration
        configurationfile="${src}/hibernate.cfg.xml"/>
      <hbm2ddl drop="true" outputfilename="book.sql"/>
    </htools>
  </target>

  <!-- Compile java source code -->
  <target name="compile" depends="prepare">
    <javac srcdir="${src}"
           destdir="${class}"
           debug="on"
           optimize="off"
           deprecation="on"
           classpathref="project.classpath"/>
  </target>

  <!-- Add a book (create and persist) -->
  <target name="addBooks" depends="compile">
    <java classname="com.dougsparling.AddBook" 
             classpathref="project.classpath"/>
  </target>

  <!-- Display persisted data -->
  <target name="listBooks" depends="compile">
    <java classname="com.dougsparling.ListBooks" 
             classpathref="project.classpath"/>
  </target>

</project>

2) build.properties

This file is included in the build.xml file. build.properties contains paths to the installed libraries.

Book/build.properties
-----------------------------------------


# Path to the hibernate install directory
hibernate.home=/usr/local/hibernate-3.2

# Path to the hibernate-tools install directory
hibernate.tools.home=/usr/local/HibernateTools

# Path to hibernate-tools.jar relative to hibernate.tools.home
hibernate.tools.path=
/plugins/org.hibernate.eclipse_3.2.0.beta9a/lib/tools

# Path to the HSQL DB install directory
hsql.home=/usr/local/hsqldb

3) Hibernate configuration file

Database connection information mappings.

Book/src/hibernate.cfg.xml
--------------------------------


<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
  "-//Hibernate/Hibernate Configuration DTD//EN"
  "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
  <session-factory>
    <property name="hibernate.connection.url">
        jdbc:hsqldb:file:data/book;shutdown=true
    </property>
    <property name="hibernate.connection.driver_class">
      org.hsqldb.jdbcDriver
    </property>
    <property name="hibernate.connection.username">sa</property>
    <property name="hibernate.connection.password"></property>
    <property name="hibernate.connection.pool_size">0</property>
    <property name="hibernate.dialect">
      org.hibernate.dialect.HSQLDialect
    </property>
    <property name="hibernate.show_sql">false</property>

    <!-- mapping resources -->
    <mapping resource="com/dougsparling/Book.hbm.xml"/>

  </session-factory>
</hibernate-configuration>

4) Logging

Set up logging. You can use the file that comes in the etc directory of the HibernateTools in the unpacked archive file.

Book/src/log4j.properties

5) Book class

POJO class to represent a book

Book/src/com/dougsparling/Book.java
-----------------------------------------


package com.dougsparling;

public class Book {
  private int id;
  private String title;

  public Book(String title) {
    this.title = title;
  }

  Book() {
  }

  public int getId() {
    return this.id;
  }

  public void setId(int id) {
    this.id = id;
  }

 public String getTitle() {
    return this.title;
  }

  public void setTitle(String title) {
    this.title = title;
  }
}

6) Object mapping for Book class

Book/src/com/dougsparling/Book.hbm.xml
-------------------------------------------


<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
          "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>

  <class name="com.dougsparling.Book" table="book">

    <id name="id" type="int" column="id">
      <generator class="native"/>
    </id>

    <property name="title" type="string"/>

  </class>
</hibernate-mapping>

7) AddBook class

Code to add a book to database

Book/src/com/dougsparling/AddBook.java
--------------------------------------------


package com.dougsparling;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

import com.dougsparling.Book;

public class AddBook {
  public static void main(String[] args) {

    String title = "A Book";

    SessionFactory factory =
      new Configuration().configure().buildSessionFactory();
    Session session = factory.openSession();
    session.beginTransaction();

    Book book = new Book(title);

    session.save(book);
    session.getTransaction().commit();
    session.close();
  }
}

8) ListBooks class

Code to read books from database

Book/src/com/dougsparling/ListBooks.java
----------------------------------------------


package com.dougsparling;

import java.util.Iterator;
import java.util.List;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

import com.dougsparling.Book;

public class ListBooks {
  public static void main(String[] args)
  {
    SessionFactory factory =
      new Configuration().configure().buildSessionFactory();
    Session session = factory.openSession();

    List books = session.createQuery("from Book").list();
    System.out.println("Found " + books.size() + " books(s):");

    Iterator i = books.iterator();
    while(i.hasNext()) {
      Book book = (Book)i.next();
      System.out.println(book.getTitle());
    }

    session.close();
  }
}

9) Ant build

At this point it's time to run Ant against the build.xml file.


kl93@oiche:/home/kl93/Book$ ant schema
kl93@oiche:/home/kl93/Book$ ant addBooks
kl93@oiche:/home/kl93/Book$ ant listBooks

Perl - DateTime

2007-04-28T05:58:00.000-07:00

Our servers were recently switched from using local time to UTC. This had an affect on our content, causing it to show several hours early since content availability is based on local time. In the past we had relied on Date::Calc on other various date manipulations using epoch seconds. Having recently worked on two projects with Catalyst, I had become familiar with the Perl module DateTime. Not only was converting UTC to local time a breeze, DateTime required far fewer lines of code, not to mention the ease and readability of date manipulations.

The standard Unix date command shows the server is on UTC:


kl93@oiche/home/kl93:$ date
Sat Apr 28 13:10:15 UTC 2007

or in Perl:


my $date = localtime(time);
print "$date\n";

returns


2007-04-28T13:16:29

Now, using DateTime module:


#!/usr/bin/perl
use strict;
use DateTime;
my $dt = DateTime->now();
print $dt->datetime(), "\n";

Output:


kl93@oiche:/home/kl93$ perl datetime1.pl
2007-04-28T13:23:15

To get local time, you can either set the desired time zone when you create the DateTime object:


#!/usr/bin/perl
use strict;
use DateTime;
my $dt = DateTime->now(time_zone => 'America/Chicago');
print $dt->datetime(), "\n";

or set it after you've created the object:


#!/usr/bin/perl
use strict;
use DateTime;
my $dt = DateTime->now();
$dt->set_time_zone('America/Chicago');
print $dt->datetime(), "\n";

Now we have local time for US Central:


kl93@oiche:/home/kl93$ perl datetime2.pl
2007-04-28T08:29:56

Using a named time zone like 'America/Chicago' is nice, as it will calculate DST changes. However, it's not recommended for dates far in the future (read the Pod).

You can also use "today" in place of "now," which will only initialize the date, not the time:


#/usr/bin/perl
use strict;
use DateTime;
my $dt1 = DateTime->today();
print "dt1: ", $dt1->datetime(), "\n";
my $dt2 = DateTime->now();
print "dt2: ", $dt2->datetime(), "\n";


kl93@oiche:/home/kl93$ perl datetime3.pl
dt1: 2007-04-28T00:00:00
dt2: 2007-04-28T17:53:32

You can also initialize the DateTime object to any valid date by passing passing parameters to the constructor:


#!/usr/bin/perl
use strict;
use DateTime;
my $dt = DateTime->new( year   => 2001,
                        month  => 4,
                        day    => 23,
                        hour   => 10,
                        minute => 45,
                        second => 30,
                        time_zone  => 'America/Chicago',
                      );
print $dt->datetime(), "\n";

We can see that the date has been initialized to April 23, 2005 at 10:45:30 (am):


kl93@oiche:/home/kl93$ perl datetime4.pl
2001-04-23T10:45:30

There are several accessors - a quick perusal of the Pod shows:


$dt->year;
$dt->month;          # 1-12 - also mon
$dt->day;            # 1-31 - also day_of_month, mday
$dt->day_of_week;    # 1-7 (Monday is 1) - also dow, wday
$dt->hour;           # 0-23
$dt->minute;         # 0-59 - also min
$dt->second;         # 0-61 (leap seconds!) - also sec
$dt->day_of_year;    # 1-366 (leap years) - also doy
$dt->day_of_quarter; # 1.. - also doq
$dt->quarter;        # 1-4

I won't cover everything, that's what the Pod is for, but a few handy features include easy date formating and date calculations.

A few formatting built-ins:


$dt->ymd;      # 2007-04-28
$dt->ymd('/'); # 2007/04/28
$dt->ymd('')   # 20070428

$dt->mdy;      # 04-28-2007
$dt->mdy('/'); # 04/28/2007
$dt->mdy('');  # 04282007

$dt->dmy;      # 28-04-200
$dt->dmy('/'); # 28/04/2007
$dt->dmy('');  # 28042007

$dt->hms;      # 12:33:45

And if you need it, you can use 'strftime' for further formatting:


$dt->strftime("%A, %B %d, %Y"); # Saturday, April 28, 2007

A few date manipulations:

You can update an existing DateTime object to another date:


#!/usr/bin/perl
use strict;
use DateTime;
my $dt = DateTime->new( year   => 2001,
                        month  => 4,
                        day    => 23,
                        hour   => 10,
                        time_zone  => 'America/Chicago',
                      );
print $dt->ymd, "\n";

$dt->set( year => 2007 );
$dt->set( month => 11 );
$dt->set( day => 30 );
print $dt->ymd, "\n";

We can see that the date was changed from 2001-04-23 to 2007-11-30:


kl93@oiche:/home/kl93$ perl datetime5.pl
2001-04-23
2007-11-30

You can find x number of years, months, days from a date by using "add" and "subtract" on your DateTime object.

To find one month from today:


#!/usr/bin/perl
use strict;
use DateTime;
my $dt = DateTime->now();
print $dt->datetime(), "\n";
print $dt->add(months => 1), "\n";

Output:


kl93@oiche:/home/kl93$ perl datetime6.pl
2007-04-28T14:05:35
2007-05-28T14:05:35

Or one month previous:


#!/usr/bin/perl
use strict;
use DateTime;
my $dt = DateTime->now();
print $dt->datetime(), "\n";
print $dt->subtract(months => 1), "\n";

Output:


kl93@oiche:/home/kl93$ perl datetime7.pl
2007-04-28T14:07:42
2007-03-28T14:07:42

One note - DateTime objects are hash references, so if you want to keep your original DateTime object unchanged, you need to clone your object and then use "add" or "subtract" to get the calculated date.

Here we simply copy $dt1 and update $dt2.


#/usr/bin/perl
use strict;
use DateTime;
my $dt1 = DateTime->now();
print "dt1: ", $dt1->datetime(), "\n";
my $dt2 = $dt1;
$dt2->add(months => 1), "\n";
print "dt2: ", $dt2->datetime(), "\n";
print "dt1: ", $dt1->datetime(), "\n";

Note that once $dt2 is modified, $dt1 is modified as well (they both "point" to the same DateTime object:


kl93@oiche:/home/kl93$ perl datetime8.pl
dt1: 2007-04-28T17:19:46
dt2: 2007-05-28T17:19:46
dt1: 2007-05-28T17:19:46

To prevent this, use the clone method to create a totally new DateTime object:


#/usr/bin/perl
use strict;
use DateTime;
my $dt1 = DateTime->now();
print "dt1: $dt1->datetime(), "\n";
my $dt2 = $dt1->clone;
$dt2->add(months => 1), "\n";
print "dt2: ", $dt2->datetime(), "\n";
print "dt1: ", $dt1->datetime(), "\n";

Now $dt1 remains unchanged:


kl93@oiche:/home/kl93$ perl datetime9.pl
dt1: 2007-04-28T17:23:39
dt2: 2007-05-28T17:23:39
dt1: 2007-04-28T17:23:39

Find out more about the DateTime module at the Perl DateTime Wiki or at CPAN (written by Dave Rolsky)

Java/Perl - Command-line arguments

2007-04-21T19:49:00.000-07:00

Command-line arguments are passed to a Perl program in the array @ARGV.

Perl


#!/usr/bin/perl
use strict;
use warnings;

my $num_args = @ARGV;
print "Length of \@ARGV array: $num_args\n";
for(my $i = 0; $i %lt; $num_args; $i++) {
  print "Argument $i = |$ARGV[$i]|\n";
}

# another way to loop through arguments
my $count = 0;
for my $arg(@ARGV) {
  print "Argument $count = |$arg|\n";
  $count++;
}

Output:


[kl93@localhost ]$ perl args.pl Eeyore Piglet "Pooh Bear"
Argument 0 = |Eeyore|
Argument 1 = |Piglet|
Argument 2 = |Pooh Bear|
Length of @ARGV array: 3
Argument 0 = |Eeyore|
Argument 1 = |Piglet|
Argument 2 = |Pooh Bear|

Command-line arguments are passed to main method in a Java program. The arguments are passed as a String array called args (or whatever you may choose to call it).

Java


public class Args
{
  public static void main(String[] args)
  {
    System.out.println("Length of args array: " 
                       + args.length);

    for(int i = 0; i < args.length; i++)
    {
      System.out.println("Argument " + i + " = |" + args[i] + "|");
    }
  }
}

Output:


[kl93@localhost ]$ java Args Eeyore Piglet "Pooh Bear"
Length of args array: 3
Argument 0 = |Eeyore|
Argument 1 = |Piglet|
Argument 2 = |Pooh Bear|

Java/Perl - String comparison (eq)

2007-04-21T19:47:00.001-07:00

In Perl, comparison operators are used when comparing either numbers or strings. For comparing strings, the comparison operator for equality is 'eq.' Unlike Java, Perl doesn't have a String class as Perl is a "typeless" language. However, Perl scalar variables can contain numbers or strings, so there isn't much difference between 999 (number) or '999' (string). So comparing strings in Perl for equality is fairly straight forward.

Perl


#!/usr/bin/perl
use strict;
use warnings;

my $string1 = 'Eeyore';
my $string2 = 'Eeyore';

if($string1 eq $string2) {
  print "True\n";
} else {
  print "False\n";
}

The output is:


True

In Java, strings are objects. In most cases when an equality comparison is made between two strings, it is the value of the two strings that we want to compare. To check if two strings have the same value, the 'equals' method is used.

Java


public class Equals
{
  public static void main(String[] args)
  {
    String string1 = "Eeyore";
    String string2 = "Eeyore";
    if(string1.equals(string2))
      System.out.println("True");
    else
      System.out.println("False");
  }
}

The output is:


True

Note that with Java, there are two ways to create a new string.

String string1 = "Eeyore";

String string2 = new String("Eeyore");

There is a subtle difference. With the the informal method, String objects are created and the JVM places them in the "literal pool," an area in JVM memory that allows shared access to String objects. In this case, before a new String object is created, the literal pool is checked to see if an identical string already exists, and if so it is reused. If not, a new String is created and added to the literal pool. That way, if several strings are created with the same value, they all point to the same String object.

With the formal method, a new String object is created even if the same string already exists. In this case the String object is placed in the JVM general memory.

To check if two Strings point to the same object, the '==' operator is used.


public class Equals2
{
  public static void main(String[] args)
  {
    String string1 = "Eeyore";
    String string2 = "Eeyore";
    String string3 = new String("Eeyore");

    if(string1.equals(string2))
      System.out.println("True");
    else
      System.out.println("False");

    if(string1.equals(string3))
      System.out.println("True");
    else
      System.out.println("False");

    if(string1 == string2)
      System.out.println("True");
    else
      System.out.println("False");

    if(string1 == string3)
      System.out.println("True");
    else
      System.out.println("False");
  }
}

The output is:


True
True
True
False

This shows that string1 and string2 have the same value and point to the same String object. This also shows that while string1 and string3 have the same value, they point to different String objects.

Java/Perl - split

2007-04-21T19:45:00.001-07:00

split breaks up (or splits) a string into "tokens" or substrings according to a separator. split uses a regular expression as the separator.

Perl



#!/usr/bin/perl
use strict;
use warnings;

my @fields = split /:/, "jim:bob:frank:steve";
foreach my $field (@fields) {
  print "$field\n";
}

my $string = "one two  three   four\tfive";
my @array = split /\s+/, $string;
foreach my $el(@array) {
  print "$el\n";
}

Output:


jim
bob
frank
steve
one 
two 
three
four 
five

Java 1.4 added the split() method to the String class.

Java


public class Split
{
  public static void main(String[] args)
  {
    String string1 = "jim:bob:frank:steve";
    String[] names = string1.split(":");
    for(int i=0; i<names.length; i++)
      System.out.println(names[i]);

    String string2 = "one two  three   four\tfive";
    String[] words = string2.split("\\s+");
    for(int i=0; i<words.length; i++)
      System.out.println(words[i]);
  } 
}

It is also possible to use the java.util.StringTokenizer to break a string into tokens.


import java.util.StringTokenizer;

public class StringToke
{
  public static void main(String[] args)
  {
    String string1 = "jim:bob:frank:steve";
    StringTokenizer st1 = new StringTokenizer(string1,":");
    while(st1.hasMoreTokens()) 
      System.out.println(st1.nextToken());
   
    String string2 = "one two  three   four\tfive";
    StringTokenizer st2 = new StringTokenizer(string2);
    while(st2.hasMoreTokens()) 
      System.out.println(st2.nextToken());
  } 
}

Output:


jim
bob
frank
steve
one
two
three
four
five

If no regular expression pattern is used, split defaults to using white space as the separator. (both in Perl and Java)

Java/Perl - Directory handles

2007-04-21T19:40:00.000-07:00

With Perl, one way to get a list of names in a given directory is to use a directory handle. On my Fedora box, Perl displays "." and ".." while Java does not.

Perl


#!/usr/bin/perl
use strict;
use warnings;

my $dir = '/home/kl93';
opendir DH, $dir or die "Cannot open $dir: $!";
foreach my  $file (readdir DH) {
  next if $file =~ /^\.\.?$/;     # skip . and ..
  print "$file\n";
}
close DH;

Java


import java.io.*;

public class ReadDir
{
  public static void main(String[] args) throws Exception
  {

    File file = new File("/home/kl93");

    if( !file.exists() || !file.canRead() )
    {
      System.out.println("Can't read " + file);
      return;
    }

    if( file.isDirectory() ) {
      String[] files = file.list();
      for(int i=0; i<files.length; i++)
        System.out.println(files[i]);
    }
    else {
      System.out.println(file + " is not a directory");
    }
  }
}

If you want to display filenames based on some sort of criteria - like all files with the .java extension for example - then it's often easiest to use a regular expression.

Perl


#!/usr/bin/perl
use strict;
use warnings;

my $dir = '/home/kl93';
opendir DH, $dir or die "Cannot open $dir: $!";
foreach my  $file (readdir DH) {
  next unless $file =~ /\.java$/;
  print "$file\n";
}
close DH;

Java


import java.io.*;
import java.util.regex.*;

public class ReadDir2
{
  public static void main(String[] args) throws Exception
  {

    File file = new File("/home/kl93");

    if( !file.exists() || !file.canRead() )
    {
      System.out.println("Can't read " + file);
      return;
    }

    if( file.isDirectory() ) {
      String[] files = file.list();
      for(int i=0; i<files.length; i++)
      {
        if(files[i].matches("^.*\\.java$"))
          System.out.println(files[i]);
      }
    }
    else {
      System.out.println(file + " is not a directory");
    }
  }
}


import java.io.*;
import java.util.regex.*;

public class ReadDir3
{
  public static void main(String[] args) throws Exception
  {

    File file = new File("/home/kl93");

    if( !file.exists() || !file.canRead() )
    {
      System.out.println("Can't read " + file);
      return;
    }

    if( file.isDirectory() ) {
      String[] files = file.list();
      Pattern pattern = Pattern.compile("\\.java$");
      Matcher matcher;
      for(int i=0; i<files.length; i++)
      {
        matcher = pattern.matcher(files[i]);
        if(matcher.find())
          System.out.println(files[i]);
      }
    }
    else {
      System.out.println(file + " is not a directory");
    }
  }
}

Sort (ascending)

Perl


#!/usr/bin/perl
use strict;
use warnings;

my $dir = '/home/kl93';
opendir DH, $dir or die "Cannot open $dir: $!";
foreach my $file (sort readdir(DH)) {
  print "$file\n";
}
close DH;

Sort desending


#!/usr/bin/perl
use strict;
use warnings;

my $dir = '/home/kl93';
opendir DH, $dir or die "Cannot open $dir: $!";
foreach my $file (reverse(sort readdir(DH))) {
  print "$file\n";
}
close DH;

dougsparling.org (kl93)

HTTP Load Testing/Tsung

Tsung

Load Testing

New Blogs - scriptrunner.com, Learning Erlang

Rails & Testing - Resources

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nullislove.com

railstips.org

andrzejonsoftware.blogspot.com

Behavior Driven Development (BDD)

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Books

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Nginx, Mongrel, Merb

Ruby - Randomize arrays and strings

Updating to RubyGems 1.3.0 on Mac OS X Leopard 10.5.4

Dynamic Details Row in GridView

Amazon S3 with Ruby aws-s3 gem

Add and remove a remote source from gem 'remote sources''

authentication token

Self Referential Associations with has_many :through

Screencast Addiction

ruby-mp3info

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CocoaMySQL - MySQL GUI for Mac OS X

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cache_fu: Conditional action-caching stops after a period of time

git

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will_paginate gem

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mod_rails

Ruby on Rails - Using External Asset Hosts

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Autotesting Javascript in Rails

Installing Ruby without openssl

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Accordion Effects with Scriptaculous

jQuery Sortable with Ajax, PHP, and MySQL

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composite_primary_keys.gem

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10 Ruby on Rails Plugins You Should Be Using

jQuery: Cookie Plugin

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Install Ruby without openssl

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How to pass variables thru a DataGrid hyperlink column

Ruby Blog

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ASP.NET Calendar Control - Misc

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Identify Button Clicked in GridView

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Formatting Date Field in Grid View

SQL Server 2005 Check Constraint

ASP .NET - C# Decimal Comparison

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Classic ASP: Sending e-mail (CDONTS -> CDOSYS)

JavaScript Style

Ruby on Rails - Legacy MySQL Database

Javascript Resources

Upgrading to PHP5 on Mac OS X 10.4

RMagick on Mac OSX

Ruby on Rails - script/console

PHP PEAR: MDB2

PHP PEAR: MDB2 Error: connect failed (localhost MySQL)

Viewing Ruby Gem documentation

Emulate PHP5 str_split() in PHP4

Gem List